Priming stimulation is known to promote the motivational effects of intracranial self-stimulation (ICSS) behavior. The runway method using priming stimulation can experimentally distinguish the reward and motivational effects of ICSS behavior. In this study, we examined the motivational effect of a drug as determined by the runway method using priming stimulation of ICSS behavior. Electrodes were implanted chronically into the medial forebrain bundle (MFB) of the rats. A lever for stimulation of the MFB was set on the opposite side of the start box in the apparatus. The rats were trained to obtain a reward stimulation (50—200 μA, 0.2 ms, 60 Hz) of the MFB by pressing the goal lever, and then priming stimulation of the MFB was applied. After priming stimulation, rats were placed in the start box of the runway apparatus and the time taken by the rat to press the lever was recorded. Priming stimulation frequency was significantly correlated with running speed (r=0.897, p<0.05). Methamphetamine (1, 3 mg/kg) induced an increase in running speed (F(3, 20)=16.257, p<0.01), and was further increased with increase in priming stimulation frequency. In addition, methamphetamine significantly enhanced the motivational effect. These results suggest that the runway method using priming stimulation of ICSS behavior may be an effective way to evaluate the enhancing effect of a drug on motivation.
Using morphological and biochemical (Western blot and cell fractionation) methods, we investigated whether peroxisomes are present in human extravillous trophoblast cells. Immortalized extravillous trophoblast cells (TCL-1) were incubated in the presence or absence of 0.5 mM clofibric acid for 3 d. In immunofluorescence staining of trophoblast cells with antibodies anti-catalase and anti-acyl-CoA oxidase (marker enzymes of peroxisomes), electron microscopy and immunoelectron microscopy, peroxisomes were detected in the cells. The size and number of peroxisomes in the trophoblast cells were smaller than those in rat liver. The number of peroxisomes was increased by clofibric acid. In Western blot experiment with antibodies anti-peroxisomal enzymes of β-oxidation system, densitometric analysis revealed approximately two fold increase in staining by clofibric acid. When we performed cell fractionation experiment using catalase as one of the peroxisomal marker enzymes, the highest activity of catalase was found in the light mitochondrial fraction. Specific activity of catalase in the light mitochondrial fraction was significantly increased to about 1.3 times higher than the control value by clofibric acid treatment. Upon Nycodenz density gradient centrifugation, the catalase activity was concentrated in the density fraction around 1.14—1.15. These findings suggest that microperoxisomes, which have a density smaller than those of rat hepatic peroxisomes, do exist in human extravillous trophoblast cells. It may also be possible to proliferate human peroxisomes in limited quantities using peroxisome proliferator of rodents.
The Transacetylase function of Calreticulin (CR) catalyzing the transfer of acetyl groups from acetoxycoumarins (AC) to certain proteins was identified for the first time in our laboratory. Protein acetyltransferase action of CR was termed Calreticulin Transacetylase (CRTAase). In the present work, CRTAase of rat tracheal smooth muscle cells (TSMC) was characterized with respect to the specificity for various AC and its role in the activation of nitric oxide synthase (NOS). 7,8-Diacetoxy-4-methylcoumarin (DAMC), a model AC, when incubated with TSMC along with L-arginine caused profound activation of NOS as compared to that with L-arginine alone. Further, the inclusion of N-ω-nitro-L-arginine methyl ester (L-NAME) along with DAMC resulted in the reduction of NO levels of TSMC to that of control, there by confirming the activation of TSMC NOS. Also, several AC were found to activate TSMC NOS in tune with their specificities to CRTAase. The results presented in this paper bear evidence for the activation of TSMC NOS by AC and their effectiveness to enhance NO of airway cells may be expected to find useful applications in respiratory diseases.
The direct interaction of Mekabu fucoidan (meFucoidan) with four functional basic proteins (sPLA2-IIA, bFGF, histone H2B and HBV core protein) and three synthetic FGF-BP peptides (sp5, GE13 and RS6) was characterized in vitro. It was found that (i) meFucoidan inhibited dose-dependently the activity of sPLA2-IIA, but not pPLA2, through its direct binding to the enzyme; (ii) sPLA2-IIA activity was sensitive to meFucoidan rather than heparin, but significantly stimulated by sulfatide; (iii) the A-kinase-mediated phosphorylation of these basic proteins, except sPLA2-IIA, and synthetic peptides, containing potent phosphorylation sites for A-kinase, was inhibited dose-dependently by meFucoidan; and (iv) two consensus meFucoidan-binding motifs (B-B-B-B-X and B-X-B-B-X; B, basic amino acid) in these basic proteins and synthetic peptides could be overlapping to the potent phosphorylation site (B-B-X-S/T) for the kinase in vitro. These results presented here suggest that meFucoidan functions as a selective inhibitor for sPLA2-IIA and the A-kinase-mediated phosphorylation of cellular meFucoidan-binding functional basic proteins in vitro.
The endoplasmic reticulum (ER) plays a critical role in the maintenance of intracellular homeostasis and its dysfunction is thought to lead to neuronal death, which results in neurodegenerative disorders. Since phospholipase C (PLC) isozymes are involved in maintenance of the intracellular Ca2+ concentration by regulating Ca2+ release from the ER, their expression might be affected by ER stress. Of these isozymes, PLC-β1 and -γ1, in particular, are known to protect cells from oxidative stress and thus alteration of their expression profile under ER stress-loaded conditions is interesting. Using primary cultured rat cortical neurons, we here examined whether expression of PLC-β1 and -γ1 was altered in ER stress-loaded neurons induced by tunicamycin (Tm). In ER stress-loaded neurons treated with Tm in the range of 0.03—3 μg/ml for 20 h, the viability of the neurons was decreased dose-dependently, the decrease being significant with 0.3 or more μg/ml, and expression of the representative ER stress markers, GRP78/BiP, and cleaved caspase-3 and -12, was increased after 24 h postincubation, confirming the induction of ER stress in the neurons. In the ER stress-loaded neurons obtained on Tm treatment, the expression level of PLC-β1 decreased dose-dependently. On the other hand, there was no difference in the PLC-γ1 protein expression level between control and ER stress-loaded neurons. Overall, we demonstrated that ER stress decreases the expression of PLC-β1, but not -γ1, in neurons.
A biologically active quinone that exhibits a growth-inhibitory effect on rat liver cancer cells was isolated from the nest of a social wasp, Vespa simillima (Vespinae, Vespidae). The structure was unambiguously determined by NMR and synthetic experiments and identified as being 7,8-seco-para-ferruginone. The synthetic quinone showed potent growth-inhibitory effects on rat hepatoma cells (IC50 value=1.9 μM). Morphological analyses of dRLh84 cells using the synthetic compound were tested. Chromatin coagulation was induced by the synthetic compound at 31.6 μM.
Dried stems of Dendrobium officinale have been used as crude drugs in traditional Chinese medicine (TCM) with good tonic efficacy. Sequences of chloroplast, nuclear and mitochondria genes and the method of genomic DNA (gDNA) suppression subtraction hybridization (SSH) were used to authenticate different populations during the process of good agriculture practice (GAP) and crude drug quality control. Six populations could be authenticated successfully by nine single sucleotide polymorphism (SNP) sites and six pairs of diagnostic primers for amplification refractory mutation system (ARMS) were also designed to identify six populations on the basis of single nucleotide polymorphism (SNPs). The remainder two populations (JSR, GGL) with the same sequences could be authenticated by SSH. One population-specific fragment was obtained by SSH and a pair of specific primers (SSH-JB01, SSH-JB02) on the specific sequence was designed to authenticate GGL population from the other populations tested. As the resultants were population-specific, the botanic origins of fifty “Fengdou” drug samples from markets could be classified. It is evident that the combined methods provide a high throughput and reliable approach for identification of D. officinale plants and “Fengdou” drugs.
Berberine is an isoquinoline plant alkaloid with a long history of being used for the treatment of many diseases in Chinese herbal medicine. Berberine has a wide range of biochemical and pharmacological effects, including antitumor activities, but its mechanism of action is not clearly understood. In this study, we investigated that the relationship between the antiproliferative activities of berberine and the apoptotic pathway associated with its molecular mechanism of action in human glioblastoma T98G cells. Berberine treatment of T98G cell lines inhibited cell proliferation and induced cell death in a dose (50—200 μg/ml) dependent manner with an IC50 value of 134 μg/ml, which was associated with an increase in G1 arrest. Western blot analysis showed that the berberine-induced G1 arrest was mediated through the increased expression of P27 and the decreased expression of cyclin-dependent kinase (CDK) 2, CDK4, cyclin D, and cyclin E proteins. Berberine treatment also markedly enhanced apoptosis in T98G cells through the induction of a higher ratio of the Bax/Bcl-2 proteins, the disruption of mitochondrial membrane potential, and the activation of procaspase-9, caspase-9, caspase-3, and poly(ADP-ribose) polymerase (PARP). Berberine can inhibit T98G cell proliferation by inducing G1 arrest and apoptosis. These results demonstrate that the berberine-induced apoptosis of T98G cells is primarily mediated through the mitochondrial/caspases-dependent pathway.
The effects of a novel amphiphilic vitamin C derivative, disodium isostearyl 2-O-L-ascorbyl phosphate (disodium 2-(1,3,3-trimethyl-n-butyl)-5,7,7-trimethyl-n-octyl-L-ascorbyl phosphate, VCP-IS-2Na), possessing a C18 alkyl chain attached to a stable sodium L-ascorbic acid 2-phosphate (VCP-Na), on the proliferation of fibroblasts and collagen synthesis, and inhibition of matrix metalloproteinase-1 (MMP-1) in normal human fibroblasts, NHDFs and NB1RGBs, were evaluated. Compared with proliferation of non-treated fibroblasts, VCP-IS-2Na at 50 μM increased proliferation to 123 and 135% of that in NHDFs and NB1RGBs. On the other hand, L-ascorbic acid (vitamin C) and VCP-Na had little effect on proliferation. At a concentration of 5.0—50 μM, VCP-IS-2Na stimulated collagen synthesis with an effectiveness comparable to that of vitamin C and VCP-Na. The amount of type I collagen in the culture medium was increased by treatment with VCP-IS-2Na for 72 h, in a concentration-dependent manner. Maximum increases of 126 and 1067% were seen with VCP-IS-2Na at 50 μM in NHDFs and NB1RGBs, respectively, whereas vitamin C and VCP-Na only had a small effect. VCP-IS-2Na had a small inhibitory effect on MMP-1, but vitamin C did not inhibit MMP-1, and VCP-Na had very little effect. VCP-IS-2Na exerted its collagen synthesis-promoting activity after being converted to vitamin C by phosphatase. This vitamin C promoted proliferation, collagen synthesis and inhibition of MMP-1, which are prolonged through sustained conversion of VCP-IS-2Na.
The mechanism of megakaryopoiesis, proplatelet formation (PPF) and platelet (PLT) production is not fully elucidated. Lactoferrin (LF) has been reported to have many biological functions including cell proliferation and differentiation, and the LF receptor is present on megakaryocytic cells. In the present study, we examined the effect of human LF (hLF) on PLT production from primary megakaryocytes (MKs). At first, we developed a PLT production system derived from human CD34+ cells by thrombopoietin (TPO) stimulation. Because the number of proplatelets, PLTs and CD41+ MKs was remarkebly increased after day 5, we employed the TPO-induced CD34+ cells on day 5. Then, the effect of hLF on PLT production from human primary MKs was examined. In the range of 3—30 μg/ml, hLF significantly inhibited PLT production up to about 60%. However, it did not significantly change the intensity of CD41 expression in MKs and the ploidy of MKs. In addition, it did not inhibit MK progenitors. These results suggest that LF directly inhibits PLT production from matured MKs, but does not inhibit megakaryopoiesis, including proliferation/maturation processes.
Chloroquine is one of the disease-modifying antirheumatic drugs (DMARDs) with anti-malarial effect. In this study, we examined the modulatory effect of chloroquine on the functional activation of β1-integrins (CD29) using CD29- and CD98 (a functional regulator of CD29)-mediated U937 cell–cell adhesion, comparing macrophage functions and T cell proliferation. Chloroquine effectively suppressed U937 cell–cell adhesion mediated by CD29 and CD98, in a protein kinase (PK) C, PKA, protein tyrosine kinase (PTK), extracellular signal-regulated kinase (ERK) and actin cytoskeleton-independent manner. Other lysomotropic agents (monesin, methylamine and ammonium chloride) also significantly diminished both CD29- and CD98-mediated cell–cell adhesion, indicating that lysomotropic character may play a critical role in regulating β1-integrin functions. Therefore, these results suggest that chloroquine may act as a novel regulator of CD29 function in a lysomotropic character-dependent novel manner.
A clone of Madin-Darby canine kidney (MDCK) cells whose cell membrane was stably labeled with expressed cyan fluorescent protein (CFP) was established, and changes in their volume and shape induced by hyposmotic stress were analyzed with confocal microscopy. The membrane-targeted CFP was present not only on the cell membrane but also in the endoplasmic reticulum and Golgi apparatus, but was excluded from the mitochondria and cell nucleus. During hyposmosis, the initial swelling and the following regulatory volume decrease could be accurately measured by summation of the cellular volume in every confocal slice crossing the cell at different heights. Changes in the cellular height roughly paralleled the changes in cellular volume when the mean value was compared, but dissociation as much as 30% was observed for individual cells due to changes in cell shape. The present experimental system, which enables direct measurement of cell volume and simultaneous observation of various intracellular phenomena, would be useful for further investigation of cellular volume regulation.
Many detrimental nematodes exist, including parasitic plant and animal nematodes. The Pleurotus ostreatus (oyster mushroom) is a famous mushroom that preys upon live nematodes. However, there have been no details reported on the mechanism of this predatory activity. Therefore, we investigated the predatory relationship between the nematode and P. ostreatus as a potential way of exterminating other various detrimental nematodes. Upon invasion by the nematode, the mushroom defends itself by causing the nematode's head to shrink in size (anti-nematode activity). Our data suggest that this anti-nematode mechanism is associated with the peroxide of linoleic acid.
We previously reported that we had cloned genes responsible for multidrug resistance from the chromosomal DNA of Klebsiella pneumoniae MGH78578 using a drug-hypersusceptible Escherichia coli strain as a host. One of the recombinant plasmids pETV6 conferred resistance to host cells against a wide range of antimicrobial agents, dyes and detergents. It was revealed that this plasmid carried the acrBKp gene and a part of the acrAKp gene coding for a multidrug efflux pump belonging to the RND family. We cloned the whole acrAKpBKp operon of K. pneumoniae and characterized the pump. The AcrAB pump utilized TolC as an outer membrane component in cells of E. coli. Elevated energy-dependent efflux of ethidium was observed with cells possessing AcrAKp BKp-TolC. We cloned a gene coding for an ortholog of TolC from chromosomal DNA of K. pneumoniae, and designated it kocC. It seems that the AcrAKpBKp-KocC complex functions as a potent multidrug efflux pump in K. pneumoniae. We observed a higher level of expression of acrAKp in K. pneumoniae MGH78578, a multidrug resistant strain, compared with ATCC10031, a drug susceptible strain.
The growth of Candida albicans was dose-dependently inhibited by addition of hinokitiol. The sensitivity of C. albicans to hinokitiol under aerobic conditions was higher than that under anaerobic conditions. Amount of ATP in C. albicans was not inhibited by hinokitiol under both conditions. The expression of mRNAs related to the growth signal, CYR1 and RAS1, was inhibited by hinokitiol. These findings suggested that the growth inhibition of C. albicans by hinokitiol was due to the interruption of RAS-signal transmission, such as the cAMP pathway.
Graves' disease, the most common cause of hyperthyroidism, is an autoimmune disorder. Antithyroid drugs have been selected as the first-line treatment of Graves' disease in Korea, Japan, and European countries. However, antithyroid drugs such as methimazole (MMI) and prophylthiouracil (PTU) have limitations in clinical applications because of their side effects. In this study, we performed a clinical trial and in vitro study to investigate the clinical effects and action mechanism of Ahnjeonbaekho-tang (AJBHT), an herbal remedy for Graves' disease. In a clinical study of Graves' disease patients who had side effects from antithyroid drugs, we found that treatment by AJBHT resulted in a reduction of serum triiodothyronine (T3) and free thyroxine (FT4) levels and an increase in thyroid stimulating hormone (TSH) levels (T3: p<0.0001, FT4: p=0.0012, TSH: p=0.0370, respectively). In vitro, AJBHT significantly inhibits FRTL-5 cell proliferation, DNA synthesis, cyclic AMP production, T4 synthesis, and the expression of thyroglobulin (Tg) mRNA in comparison with the control. These results suggest that AJBHT might suppress T4 synthesis by modulating adenosine 3′,5′-cyclic monophosphate (cAMP) and Tg expression, and therefore, AJBHT could be an alternative therapy for Graves' disease patients who have side effects from antithyroid drugs.
Hydroxydihydrocarvone (HC) is a synthetic intermediate obtained from R-(−)-carvone hydration. Due to the chemical and structural similarity between HC and other monoterpenes with psychopharmacological activity, this study was carried out to investigate the possible central antinociceptive effect of intraperitoneally administered HC, and to evaluate its effect on the opioid system in mice. In the tail immersion test, the time of the response to the thermal noxious stimulus was longer in the animals that received HC (200 mg/kg). In the hot plate test, HC (100—200 mg/kg) significantly increased the time mice stayed on the apparatus. In the formalin test, HC was effective in both phases of the test with significant dose-dependent response (50—200 mg/kg), showing central antinociceptive activity. In addition, HC (25—200 mg/kg) did not induce catalepsy in mice. In an attempt to evaluate the mechanism of action of HC, the mice were pretreated with naloxone (5 mg/kg, s.c.). The effect of HC on the formalin and hot plate tests was not blocked by naloxone. Therefore, HC has an antinociceptive effect on the central nervous system without causing catalepsy. These results suggest the nonparticipation of the opioid system in the modulation of pain by HC.
Triptolide, a purified diterpenoid triepoxide compound derived from a traditional Chinese medicine, Tripterygium wilfordii HOOK. f (TWHf), has been used in the treatment of autoimmune and inflammatory diseases. However, the toxicity of triptolide limits its application to a great extent. In the present study, we treated human normal liver L-02 cells (L-02 cells) with triptolide in vitro and investigated its toxic effects. The cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for cellular viability and by flow cytometry and Hoechst 33258 staining for apoptosis. The mitochondrial membrane potential (Δψm) was evaluated by flow cytometry with JC-1 as probe. After treatment with triptolide, a decrease in the viability of L-02 cells and increase in apoptosis were observed. Triptolide-induced apoptosis was accompanied by loss of mitochondrial membrane potential and release of cytochrome c (cyt-c) from the mitochondria to the cytosol and down-regulation of anti-apoptotic protein Bcl-2 levels with concurrent up-regulation in pro-apoptotic protein Bax levels and tumor suppressor protein p53 levels. Triptolide-increased activity of caspase 9 and caspase 3 was also observed. These results indicate that triptolide induced cytotoxicity in L-02 cells by apoptosis, which is mediated through mitochondrial pathway.
Computer simulations of the human α1a-adrenergic receptor (α1a-AR) based on the crystal structure of rhodopsin have been combined with experimental site-directed mutagenesis to investigate the role of residues in the transmembrane domains in antagonist binding. Previous molecular dynamics studies from our laboratory indicated that the amino acids Asp106 in the third transmembrane domain (TMD), Gln167 in TMD IV of α1a-AR were directly involved in prazosin, tamsulosin and KMD-3213 binding. The Asp106Ala mutant did not exhibit any affinity for [3H]prazosin. On the other hand, the Gln167Phe mutant α1a-AR showed reduced binding affinity for [3H]prazosin. In competition binding experiment the binding affinities of prazosin and tamsulosin were increased 11-fold and 33-fold respectively to Gln167Phe mutant in comparison with wild type receptor. It seems that mutation of this residue by phenylalanine has offered more interaction for the ligands with its aromatic ring. The results provide direct evidence that these amino acid residues are responsible for the interactions between α1a-AR and radioligand [3H]prazosin as well as tamsulosin and KMD-3213.
Schisandrin B (Sch B), a dibenzocyclooctadiene derivative isolated from the fruit of Schisandra chinensis, has been shown to protect against oxidative damage in liver, heart and brain tissues in rodents. In the present study, the effect of long-term Sch B treatment (1—10 mg/kg/d×15) on gentamicin-induced nephrotoxicity was examined in rats. Sch B treatment protected against gentamicin-induced nephrotoxicity, as evidenced by significant decreases in plasma creatinine and blood urea nitrogen levels. The nephroprotection was associated with the enhancement in renal mitochondrial antioxidant status, as assessed by the level/activity of reduced glutathione, α-tocopherol and Mn-superoxide dismutase, as well as the improvement/preservation of mitochondrial functional and structural integrity, as assessed by the extents of ATP generation capacity, malondialdehyde production, Ca2+ loading and cytochrome c release, as well as the sensitivity to Ca2+-induced permeability transition, in control and gentamicin-intoxicated rats. In conclusion, long-term Sch B treatment could enhance renal mitochondrial antioxidant status as well as improve mitochondrial functional and structural integrity, thereby protecting against gentamicin nephrotoxicity.
It has been demonstrated that adipose-derived stem cells (ADSCs) secrete cytokines and exhibit diverse pharmacological actions. The present study examined the unknown pharmacological action of ADSCs regarding whitening effects. A conditioned medium of ADSCs (ADSC-CM) was harvested and the whitening effect of ADSC-CM was studied in melanoma B16 cells. ADSC-CM treatment inhibited the synthesis of melanin and the activity of tyrosinase in a dose dependent manner. To clarify the underlying mechanisms of the whitening action of ADSCs, protein levels of melanogenic proteins were measured by Western blot. Although expressions of microphthalmia-associated transcription factor and tyrosinase-related protein 2 (TRP2) remained unchanged, those of tyrosinase and TRP1 were down-regulated. Transforming growth factor-β1 (TGF-β1), a potent regulator of melanogenic proteins, was neutralized by the addition of a blocking antibody to ADSC-CM, and down-regulated expression of tyrosinase and TRP1 was almost reversed. Collectively, these results indicate that secretary factors of ADSC inhibit melanin synthesis by down-regulating the expression of tyrosinase and TRP1, which are mainly mediated by TGF-β1.
Quercetin, one of the flavonoids, is a compound of low molecular weight found in various plants and shows a wide range of diverse neuropharmacological actions. In fruits and vegetables, quercetin exists as monomer- (quercetin-3-O-rhamnoside) (Rham1), dimer- (Rutin), or trimer-glycosides [quercetin-3-(2G-rhamnosylrutinoside)] (Rham2) at carbon-3. In the previous studies, we demonstrated that quercetin inhibits both glycine and 5-hydroxytryptamine type 3, (5-HT3A) receptor channel activities expressed in Xenopus oocytes. However, the effects of quercetin glycosides on glycine and 5-HT3A receptor channel activities are not well known. In the present study, we investigated the effects of quercetin glycosides on the human glycine α1 receptor and mouse 5-HT3A receptor channel activities expressed in Xenopus oocytes using a two-electrode voltage clamp technique. In oocytes expressing glycine or 5-HT3A receptors, quercetin- or its glycosides-induced inhibitions on glycine- (IGly) and 5-HT-induced current (I5-HT) were dose-dependent and reversible. Applications of quercetin and its glycosides inhibited IGly in order of quercetin>Rutin≥Rham1>Rham2. Applications of quercetin and its glycosides inhibited I5-HT in order of Rham2≥quercetin>Rutin=Rham1. The inhibitions of IGly by quercetin glycosides were non-competitive and voltage-sensitive, whereas the inhibitions of I5-HT by quercetin glycosides were competitive and voltage-insensitive manners. These results also indicate that quercetin glycosides might regulate the human glycine α1 and mouse 5-HT3A receptors with differential manners.
Neuroblastoma is the most common solid tumor in children. Despite aggressive chemotherapy, the prognosis of patients with advanced neuroblastoma is still very poor. Our recent study showed that xanthoangelol, a major chalcone constituent of the stem exudates of Angelica keiskei, induced caspase-3-dependent apoptosis in neuroblastoma cells. However, details of the mechanism underlying its apoptotic action are still unclear. Here we show that xanthoangelol triggers oxidative stress by generation of reactive oxygen species and induces apoptosis through release of cytochrome c and activation of caspase-9 in IMR-32 cells. Pretreatment with an antioxidant, vitamin E, prevented the increase of reactive oxygen species and apoptosis induced by xanthoangelol. Proteomic analysis using 2-dimensional electrophoresis and MALDI-TOF-MS revealed that DJ-1 protein was involved in xanthoangelol-induced apoptosis. DJ-1 responded to its oxidative stress status by being oxidized itself. Furthermore, DJ-1 was down-regulated by xanthoangelol, leading to loss of antioxidant function and acceleration of apoptosis. We also show that xanthoangelol has a cytotoxic effect on drug-resistant LA-N-1 and NB-39 cells as well as drug-sensitive IMR-32 and SK-N-SH cells. These findings suggest that xanthoangelol induces apoptosis by increasing reactive oxygen species and targeting DJ-1, and such mechanism may be an effective therapeutic approach for advanced neuroblastoma.
Human ether-à-go-go-related gene (HERG) encodes the rapid component of the cardiac delayed rectifier K+ current, which has an important role in the repolarization of the cardiac action potential. QT interval prolongation through HERG channel inhibition is associated with a risk of torsade de pointes arrhythmias and is a major challenge for drug development. The effects of the novel antiviral drug sophocarpine (SC) were examined on stably expressed HERG channels in human embryonic kidney (HEK293) cells using a whole-cell patch clamp technique, Western blot analysis and immunofluorescence experiments. SC inhibited HERG channels in a concentration-dependent manner, with an IC50 of 100—300 μM. SC significantly accelerated channel inactivation, recovery from inactivation and onset of inactivation. In addition, it had no effect on channel activation and deactivation. Based on Western blot and immunofluorescence results, SC had no significant effect on the expression of HERG protein. In summary, SC is a potent blocker of HERG K+ channels that functions by changing the channel inactivation kinetics. In addition, SC has no effect on the generation and trafficking of HERG protein.
Refined Qing Kai Ling (RQKL) is an improved injectable multi-component preparation derived from Qing Kai Ling, which could offer the neuroprotection effect in middle cerebral artery occlusion (MCAO) model of rats by relieving the damage of vascular endothelial cell as well as inhibiting the process of inflammation. Herein, we observed whether RQKL could exert influence on the expression of endothelial nitric oxide synthase (eNOS), as a mechanism of its protective effects against ischemia. Sprague-Dawley rat model of focal cerebral ischemia was established by permanent filament occlusion of the left middle cerebral artery. We found that the administration of RQKL could reduce the ischemic infarct size as well as neurological deficit of model rats. Furthermore, it was showed that the eNOS level was consistently increased in endothelium of blood vessels of the ischemic penumbra after 2 to 72 h of permanent MCAO, and the expression of eNOS increases more in animals treated with RQKL. Our results suggested that eNOS levels in penumbral zone were enhanced after permanent focal ischemia, and RQKL could stimulate postischemic eNOS expression, which may be an important mechanism in RQKL's protection against cerebral ischemia.
Oseltamivir phosphate (Tamiflu), an anti-influenza virus drug, is hydrolyzed by carboxylesterase to an active metabolite. The metabolite inhibits the influenza virus-specific neuraminidase. In this study, the effects of oseltamivir on normal core body temperature were studied in mice. Oseltamivir (30—300 mg/kg, intraperitoneally (i.p.) and 100—1000 mg/kg, orally (p.o.)) dose-dependently lowered the body temperature. The effects of oseltamivir (p.o.) continued longer than those of oseltamivir (i.p.), and approximately triple doses of oral oseltamivir were needed to produce the same peak effects as intraperitoneal oseltamivir. The non-steroidal anti-inflammatory drug diclofenac (1—30 mg/kg, i.p.) did not affect body temperature, and (at 30 and 60 mg/kg, s.c.) did not interact with the hypothermic effects of oseltamivir (100 mg/kg, i.p.). Zanamivir, which also inhibits neuraminidase, did not produce hypothermia at doses of 100 and 300 mg/kg, i.p. Clopidogrel (100, 300 mg/kg, i.p.), which is metabolized by the same carboxylesterase, tended to decrease the hypothermic effects of oseltamivir (100 mg/kg, i.p.). These results suggest that the hypothermic effects of oseltamivir are due to its hydrolytic metabolite, and that the hypothermia observed in mice has some relationship to the antipyretic effects and severe hypothermia (adverse event) observed in influenza patients after taking oseltamivir.
The hepatoprotective effects of a diterpenoid acanthoic acid isolated from Acanthopanax koreanum NAKAI were evaluated in a D-galactosamine/lipopolysaccharide-induced fulminant hepatic failure mouse model. Mice were pretreated orally with acanthoic acid 12 and 1 h before intraperitoneal injection of D-galactosamine and lipopolysaccharide. Pretreatment with the compound markedly reduced lethal liver injury in experimental animals. The effects were likely associated with a significant decrease in serum tumor necrosis factor (TNF)-α levels, which are correlated not only with those of alanine aminotransferase and aspartate aminotransferase but also with the reduced number of apoptotic hepatocytes in the liver as confirmed using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling method and DNA fragmentation assay. These results suggest that acanthoic acid protects against D-galactosamine/lipopolysaccharide-induced fulminant liver failure at least in part by a mechanism associated with the down-regulation of TNF-α secretion.
The ethanol extract of Geranium carolinianum L., a domestic plant grown in China, was subjected to sequential extractions with different organic solvents. The extracts were assayed for anti-hepatitis B virus (HBV) activities. The ethyl acetate fraction was found to contain the highest level of anti-HBV activity. In order to identify the active ingredients, the ethyl acetate fraction was further fractionated by column chromatography. Seven compounds were identified including ellagic acid, geraniin, quercitrin, hyperin, hirsutrin, quercetin, and kaempferol, whose structures were determined by NMR. The presence of the anti-HBV compounds geraniin, ellagic acid and hyperin in G. carolinianum L. may account for the effectiveness of this folk medicine in the treatment of HBV infections. Geraniin inhibited hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) secretion by more than 85.8% and 63.7%, respectively, at the non-cytotoxic concentration of 200 μg/ml. The inhibitions of HBsAg and HBeAg secretion by geraniin were higher than the inhibition by the positive control Lamivudine, 33.5% and 32.2% respectively, at the same concentration. Since HBeAg is involved in immune tolerance during HBV infection, the newly identified anti-HBV compound geraniin might be a candidate agent to overcome the immune tolerance in HBV-infected individuals. This is the first report of the anti-HBV effects of geraniin and hyperin, the active substances derived from G. carolinianum L.
Although Panax ginseng has been widely used in oriental countries for pharmacological effects such as anti-diabetic, anti-inflammatory, adaptogenic and anti-fatigue activities, the active ingredient is not yet fully identified. In our preliminary studies, protopanaxadiol ginsenosides showed the insulin secretion-stimulating activity. In HIT-T15 cells, Rg3 enhanced the insulin secretion in a concentration dependent manner. This effect, however, was almost completely abolished in the presence of diazoxide (K+ channel opener) or nifedipine (Ca2+ channel blocker). Oral glucose tolerance test (OGTT) was also performed using ICR mice and Rg3 suppressed the blood glucose levels from rising by enhancing an insulin secretion at 30 min after administration. From these studies, we may conclude that Rg3 lowered the plasma glucose level by stimulating an insulin secretion and this action was presumably associated with ATP sensitive K+ channel. Next, to explore the hypothesis that ginsenoside Rg3 epimers may exhibit differential effects, glucose-stimulated insulin secretion activity and phosphorylation of AMP-activated protein kinase (AMPK) were compared between 20(S)- and 20(R)-ginsenoside Rg3. 5 μM of 20(S)-Rg3 enhanced the glucose-stimulated insulin secretion by 58% compared to the control, but 20(R)-Rg3 did not show any effect. In C2C12 myotubes, 20(S)- and 20(R)-Rg3 both markedly phosphorylated AMPK and acetyl-CoA carboxylase (ACC), although 20(R)-Rg3 showed a little less effect. Taken together, our results suggest that ginsenoside Rg3 epimers showed differential activities, and 20(S)-Rg3 epimer exhibited the higher pharmacological effects in insulin secretion and AMPK activation than 20(R)-Rg3. The novel characteristics of 20(S)-Rg3 may be a valuable candidate for anti-diabetic agent.
Using mice, we examined whether the topical application of tacrolimus would produce an acute anti-pruritic effect. An itch-related response, scratching, was elicited by intradermal injections of mosquito allergen (10 μg/site) in sensitized mice and SLIGRL-NH2 (protease-activated receptor-2 agonist, 50 nmol/site), histamine (100 nmol/site), serotonin (100 nmol/site) and substance P (100 nmol/site) in naive ones. Topical application of 1%, but neither 0.1% nor 0.3%, tacrolimus to the skin 1 h before injection inhibited scratching induced by mosquito allergen and SLIGRL-NH2, without effects on scratching induced by histamine, serotonin, and substance P. Topical tacrolimus also inhibited licking induced by an intraplantar injection of capsaicin (0.1 μg/site). These results suggest that topical tacrolimus exerts acute inhibitory effects on allergic and protease-activated receptor-2-mediated itching. Though precise mechanisms remain unclear, the action on sensory neurons expressing protease-activated receptor-2 and transient receptor potential vanilloid-1 capsaicin receptor may be involved in the inhibitory effects of tacrolimus.
The root of Ilex pubescens (Mao-Dong-Qing in Chinese, MDQ) has been commonly used for treatment of cardiovascular and inflammatory diseases in the Chinese medical system. The current studies aimed to investigate the anti-inflammatory and analgesic effects as well as the underlying mechanisms of a purified saponin fraction (PSF) derived from MDQ. PSF was found to significantly suppress the paw edema of rats induced by histamine given intraperitoneally at dosages ranging from 12.5—100 mg/kg. Meanwhile, PSF given orally at dosages of 200 and 100 mg/kg significantly inhibited acetic acid-induced abdominal writhing response of mice and prolonged the time required for mouse tail flick after exposure to a source of radiant heat. The mechanistic studies showed that cyclooxygenase-2 (COX-2) protein expression in carrageenan-injected paw tissues of rats was markedly attenuated by intraperitoneal injection of PSF at dosages of 12.5 to 100 mg/kg. PSF could also markedly inhibit production of proinflammatory cytokines, especially IL-1β, IL-6 and TNF-α, but enhance production of anti-inflammatory cytokines of IL-4 and IL-10 in the carrageenan-injected paw tissues in rats. These effects resulted in an overall attenuation of the ratio of proinflammatory/anti-inflammatory cytokines and, ultimately suppression of the paw edema. In conclusion, the current study has demonstrated the in vivo anti-inflammatory and analgesic effects of PSF, and suggested that the molecular mechanisms might be associated with inhibition of the elevated expression of COX-2 protein and the overproduction of the proinflammatory cytokines, as well as augmentation of the anti-inflammatory cytokines IL-4 and IL-10 in the carrageenan-injected paw tissues of rats.
Corosolic acid (CRA), a constituent of Banaba leaves, has been reported to exert anti-hypertension, anti-hyperinsulinemia, anti-hyperglycemia, and anti-hyperlipidemia effects as well as to induce anti-inflammatory and anti-oxidative activities. The aim of this study was to investigate the inhibitory effects of CRA on the development of obesity and hepatic steatosis in KK-Ay mice, a genetically obese mouse model. Six-week-old KK-Ay mice were fed a high fat diet for 9 weeks with or without 0.023% CRA. Nine-week CRA treatment resulted in 10% lower body weight and 15% lower total fat (visceral plus subcutaneous fat) mass than in control mice. CRA treatment reduced fasting plasma levels of glucose, insulin, and triglyceride by 23%, 41%, and 22%, respectively. The improved insulin sensitivity in CRA-treated mice may be due on part to the increased plasma adiponectin and white adipose tissue (WAT) AdipoR1 levels. In addition, CRA treatment increased the expression of peroxisome proliferator-activated receptor (PPAR)α in liver and PPARγ in WAT. This is the first study to show that CRA treatment can contribute to reduced body weight and amelioration of hepatic steatosis in mice fed a high fat diet, due in part to increased expression of PPARα in liver and PPARγ in WAT.
In the course of search for potent chitin synthase inhibitors from plant extracts, the chitin synthase 2 inhibitors, O-methyl pisiferic acid and 8,20-dihydroxy-9(11),13-abietadien-12-one which have diterpene skeleton, were isolated from the leaves of Chamaecyparis pisifera. These compounds inhibited chitin synthase 2 of Saccharomyces cerevisiae with the IC50 values of 5.8 and 226.4 μM, respectively. Especially, O-methyl pisiferic acid showed 15.3-fold stronger inhibitory activity than polyoxin D (IC50=88.6 μM), a well-known chitin synthase inhibitor. These compounds exhibited weaker inhibitory activities against chitin synthase 1 than chitin synthase 2, whereas it showed no inhibitory activity for chitin synthase 3. The compound exhibited mixed competitive inhibition with respect to UDP-N-acetyl-D-glucosamine as substrate (Ki=5 μM). These results indicated that O-methyl pisiferic acid is a specific inhibitor of chitin synthase 2. The compound also inhibited chitin synthase 1 of Candida albicans, which represents analogues to chitin synthase 2 of S. cerevisiae, with an IC50 of 75.6 μM, which represents 1.8-fold weaker activity than that of polyoxin D. Although O-methyl pisiferic acid has been reported for antibacterial and insecticidal activities, the present study is the first report on its inhibitory activity against chitin synthase 2.
To identify the hepatoprotective component from the leaves of Cirsium setidens (Compositae), the methanolic extract was divided into two fractions, chloroform and butanol fractions, and their hepatoprotective efficacy was evaluated in a rat model of hepatic injury caused by D-galactosamine (GalN). Hepatoprotective activity was measured by the activity of serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH). Glutathione metabolism was measured via biochemical parameters such as glutathione (GSH), glutathione reductase (GR), γ-glutamylcysteine synthetase (GCS), glutathione S-transferase (GST), and superoxide dismutase (SOD) levels. We subjected the butanol fraction, which had higher activity, to column chromatography to yield pectolinarin, which was further hydrolyzed to yield pectolinarigenin. Administration (10, 20 mg/kg, p.o.) of the main flavonoid glycoside component, pectolinarin, and its aglycone, pectolinarigenin, for 2 weeks significantly decreased the activity levels of AST, ALT, ALP and LDH, indicating that the two compounds have hepatoprotective activity. Pectolinarin and pectolinarigenin also increased activity levels of GSH, GR, GCS, and GST, as well as SOD. The significant effect was only seen in SOD activity. This suggests that the two components exhibit hepatoprotective activity mainly via SOD antioxidant mechanism.
In an effort to characterize active principles for diabetic complication from medicinal mushroom, aldose reductase inhibitors were isolated from the fruiting body of Phellinus linteus and identified as hispidin (5), phelligridimer A (6), davallialactone (7), methyldavallialactone (8), hypholomine B (9), interfungins A (10), and inoscavin A (11), together with protocatechuic acid (1), protocatechualdehyde (2), caffeic acid (3), and ellagic acid (4). Their structures were elucidated by spectroscopic analyses. Among them, davallialactone (7), hypholomine B (9), and ellagic acid (4) exhibited potent rat lens aldose reductase and human recombinant aldose reductase inhibitory activity with IC50 values of 0.33, 0.82, 0.63 μM and 0.56, 1.28, 1.37 μM, respectively.
Using skin as a port for systemic drug administration, transdermal drug delivery has expanded greatly over the last two decades. Our aim was to formulate the single layer drug-in-adhesive transdermal patch for 6-mercaptopurine (6-MP). In vitro permeation study was carried out using modified Franz diffusion cell with and without of different concentration of d-limonene in human cadaver skin. In vivo immunomodulatory was carried out in mice, cumulative skin irritation, sensitization and patch adherence study was done in both mice and human subjects. 6-MP flux increased from 43±12.2 μg/cm2h (control) to 162.8±32.2 μg/cm2h (6% w/v d-limonene) data was significant (p<0.05), with decrease in the lag time to 35±9.3 min compared to control of 90 ±15.3 min. In vivo immunomodulatory effect was shown in the Balb/c mice with 100 μmol/kg/body wt of animal for 5d (one dose/d) of d-limonene. WBC count of 13469 cells/mm peak was observed on 12th day, bone marrow cells of 26.3×106 cells/femur and α-esterase positive cells of 1259±328.4 cells/4000 bone marrow cells. Cumulative skin irritation, sensitisation and patch adherence in animals and human subjects showed no skin irritation and sensitization. Patch adhesion was greater than 90.0% respectively in both human subjects and mice. The percentage of human subjects with adhesive residue was significantly less with scores of zero. d-Limonene proved as good chemical enhancer by increasing in the skin permeability with shortened the lag time. It proved that therapeutic amount of 6-MP can be delivered through transdermal drug delivery.
Gentamicin-Eudragit RS100 microspheres were prepared by modified double emulsion method. A 32 full factorial experiment was designed to study the effects of the composition of outer aqueous phase in terms of amount of glycerol (viscosity effect) and sodium chloride (osmotic pressure gradient effect) on the entrapment efficiency and % yield and microsphere size. The results of analysis of variance test for responses measured indicated that the test is significant (p>0.05). The contribution of sodium chloride concentration was found to be higher on entrapment efficiency and % yield, whereas glycerol produced significant effect on the mean diameter of microspheres. Microspheres demonstrated spherical particles in the size range of 33.24—60.43 μm. In vitro release profile of optimized formulation demonstrated sustained release for 24 h following Higuchi kinetics. Finally, drug bioactivity was found to remain intact after microencapsulation. Response surface graphs are presented to examine the effects of independent variables on the responses studied. Thus, by formulation design important parameters affecting formulation characteristics of gentamicin loaded Eudragit RS100 microspheres can be identified for controlled delivery with desirable characters in terms of maximum entrapment and yield.
Liquid intraurethral prostaglandin E1 (PGE1) delivery system was developed using self-microemulsifying drug delivery system (SMEDDS). For this, pseudo-ternary phase diagrams were constructed and characterized. The viscosity of optimized formulation was increased gradually upon the addition of water and it was decreased from the water contents over 40%. With excessive mass of water, the present system transformed to a free flowing microemulsion. These results demonstrate that the present liquid PGE1 SMEDDS formulation might stay in the urethra as a viscous sol or gel state with contacting the moisture of urethra and easily eliminated by urination. Draize test and long-term stability study revealed that the present system would be safe and PGE1 would be stable for more than one year at 4 °C, respectively. In the feline animal model, SMEDDS formulation was as effective as PGE1 intracavernosal injections in terms of ICP (intracavernosal pressure), penile length increment, and erection sustaining time was more elongated than PGE1 injections. Therefore, SMEDDS was considered as a promising PGE1 intraurethral liquid formulation for erectile dysfunction treatment.
The purpose of this study was to prepare and evaluate the intravenous emulsion (BCOE) containing Brucea javanica oil (BJO) and Coix seed oil (CSO), which is used in anti-tumor treatment. The formulation and preparation of BCOE were systematically investigated. High-pressure homogenization, particle size distribution, ζ-potential and HPLC were carried out. The pharmacokinetics of the main component, oleic acid, and anti-tumor activity studies about the tumor growth inhibitory ratios (TGIR) and the mortality experiments were also employed to evaluate BCOE in vivo compared with BJO emulsion (BJOE) and CSO emulsion (CSOE) using S180 sarcoma-bearing mice. The final BCOE formulation was 10% (w/v) oils with BJO and CSO 3 : 1, 0.6% (w/v) Lipid E 80, 0.3% (w/v) Pluronic F-68 (F-68), 0.1% (w/v) sodium oleate and 2.5% (w/v) glycerin in water. The preparation conditions involved 70 °C for preparing the crude emulsion, 6 cycles for high-pressure homogenization at 500 bar, pH value was adjusted to 8.5 after high-pressure homogenization and 115°C for 30 min in a rotating water bath for sterilization. The pharmacokinetics parameters showed the combination of BJO and CSO may not influence the elimination of BCOE and have no significant difference between BCOE and BJOE or CSOE. The data of TGIR and mortality indicated that BCOE could increase the anti-tumor activity of CSOE and reduced the toxicity of BJOE. The mortality study (BCOE 0, BJOE 63.3%, CSOE 13.3%) showed that BCOE greatly reduced the toxicity of BJOE and CSOE. Therefore, the development and application of BCOE will make an important contribution to anti-tumor therapy.
p-Phenylenediamine (PPD) has been used as one of the ingredients in hair dye. The purpose of this study is to investigate the skin toxicity of PPD application in a tungstate-induced xanthine oxidase (XO) deficient animal model. PPD (2.5% PPD in 2% NH4OH) was applied to rat skin (25 mg/16.5 cm2) five times every other day in rats fed a standard diet (SD) or a tungstate supplemented diet (TD). The skin structure in the SD and the TD group was intact, whereas XO activity was not detected in the TD group during experimental periods. Furthermore, there were no differences between the SD and the TD group in dermal reactive oxygen species (ROS) scavenging enzymes. In these experimental conditions, although XO activity was not detected in the applied PPD rats fed a tungstate supplemented diet (PTD) group, it showed more severe tissue damage compared with the applied PPD rats fed a standard diet (PSD) group. In addition, the PTD group showed higher increased rates of ROS scavenging enzyme activity and lipid peroxide (LPO) content, and decreased glutathione (GSH) content than in the PSD group. In conclusion, the increase of PPD dermal toxicity in tungstate-induced XO deficient animals may be due to excessive ROS via ROS imbalance during PPD skin application.
Some plants classified in the genus Artemisia are used for medicinal purposes. In particular, A. iwayomogi, which is referred to as ‘Haninjin,’ is used as an important medicinal material in traditional Korean medicine. However, A. capillaris, and both A. argyi and A. princeps, referred to as ‘Injinho’ and ‘Aeyup,’ respectively, are used for purposes other than those for which ‘Haninjin’ is utilized. However, it is occasionally difficult to differentiate ‘Haninjin’ from ‘Injinho’ and/or ‘Aeyup’ on the basis of their morphological features, particularly when in the dried and/or sliced form. Therefore, the development of a reliable method by which to discriminate ‘Haninjin’ from other Artemisia herbs, especially ‘Injinho’ and ‘Aeyup,’ is clearly necessary. We recently determined that the RAPD (random amplified polymorphic DNA) technique can be used to discriminate efficiently between some Artemisia herbs. In particular, when applied to RAPD, the non-specific UBC primer 391 (5′-GCG AAC CTC G-3′) was demonstrated to amplify PCR products specific to A. iwayomogi. Based on the nucleotide sequences of the PCR product, we designed a 2F1 (5′-ACC TCG GAC CTA AAT ACA-3′)/ 2F3 (5′-TTA TGA TTC ATG TTC AAT TC-3′) primer set to amplify a SCAR (sequence-characterized amplified region) marker of A. iwayomogi. Employing this primer set, along with two other primer sets amplifying SCAR markers of ‘Aeyup’ (A. argyi and A. princeps) and both ‘Injinho’ (A. capillaris) and A. japonica, which are classified into the same subgroup in a phenogram constructed from RAPD analysis, we developed a multiplex PCR method by which A. iwayomogi could be discriminated with certainty from other Artemisia herbs. Via this method, we determined not only whether the tested Artemisia herb was A. iwayomogi, but also which Artemisia herbs were tested concurrently with A. iwayomogi.
Sulfated-polysaccharides are exploited as antithrombotic and anticoagulant agents and suggested to be immunostimulants. The sulfated-polysaccharide isolated from the red-marine-algae Champia feldmannii (Cf-PLS) was purified by ion exchange chromatography and tested in experimental protocols of coagulation, inflammation (in Wistar rats) and nociception (in Swiss mice). Cf-PLS was tested i.v. for its anti-inflammatory activity in the paw-edema induced by classical inflammatory stimuli and s.c. for its pro-inflammatory activity in the paw-edema and peritonitis models. The anticoagulant activity was evaluated by the test of partial thromboplastin activation time (aPTT) and the antinociceptive effect in the writhing-test. Cf-PLS was not anti-inflammatory, but rather induced maximal edematogenic activity at 0.9 mg/kg (1.01±0.030×0.06±0.03 ml) compared to controls (0.06±0.03 ml), increased vascular-permeability (38.44±12.63×11.29±3.91 μg/g) and stimulated neutrophil migration (3.348±295×307±99 cells/μl) 1 h after injection. Cf-PLS was also antinociceptive (6.6±1.28×33±1.44 writhes) and extended human plasma coagulation time by 3 times. Our data suggest that this molecule may be an important immunostimulant.
The metastasis of tumor cells is one of the major obstacles to successful clinical therapy. A treatment strategy by incorporating a specific inhibitor of thrombin, recombinant hirudin with stealthy liposomal vinblastine, was used in this study for inhibiting the metastasis of tumor cells and enhancing the efficacy of anti-tumor agents. In vitro cytotoxicity, cell adhesion to extracellular matrix (ECM) proteins, and cell invasion and migration assays were performed on human A375 melanoma cell line. In vivo measurement of coagulation parameters, inhibition of tumor growth, and inhibition of metastasis were assessed in female BALB/c mice. In vitro, vinblastine or stealthy liposomal vinblastine alone was effective to inhibit the growth of A375 cells. On the contrary, hirudin had no influence on either cytotoxicity when treating with hirudin alone or hirudin plus vinblastine. In addition, in vitro results showed that hirudin had no impact on the adhesion of tumor cells to extracellular matrix proteins, and metastasis and invasion of tumor cells. In mice, hirudin significantly inhibited the activity of thrombin. Furthermore, administered at the initial implantation of murine B16 melanoma cells, hirudin evidently delayed the growth of tumor, and depressed the occurrence of experimental lung metastasis. A subsequent administration of stealthy liposomal vinblastine resulted in further inhibiting growth and metastasis of tumor, indicating that hirudin plus stealthy liposomal vinblastine exhibited a significant anti-metastasis effect and slightly potent effect against tumor growth as compared with stealthy liposomal vinblastine alone. In conclusion, administration of recombinant hirudin followed by giving stealthy liposomal vinblastine may be beneficial for inhibiting the growth and metastasis of melanoma in vivo. The likely mechanism could be associated with inhibition of thrombin after administration of hirudin.
Malaria is one of the major public health problems of Bangladesh. We investigated the mosquito populations infected with malaria parasites in a malaria-endemic area Chakaria, Bangladesh, where Anopheles dirus and Anopheles minimus are the principal vectors. Anopheles mosquitoes were collected with a CDC miniature light trap from inside households in June 2007. A total of 868 mosquitoes were collected, among which females numbered 669 (77.1%). The species of female Anopheles mosquitoes were identified morphologically, and 651 were A. minimus and the remaining 18 were other Anopheles species. Malaria parasite DNA from individual female mosquitoes was extracted and distinguished using the microtiter plate hybridization (MPH) technique targeting the 18S rRNA of human malaria parasites. Nineteen mosquitoes were malaria parasite positive: 12 for Plasmodium falciparum, 1 for Plasmodium vivax, and 6 for both P. falciparum and P. vivax. This is the first time that the MPH technique was used for distinguishing malaria parasites in mosquitoes and the first report from Chakaria. Our results may contribute to planning and assessing malaria control strategies in Chakaria.
Prolonged exposure to high level of estrogen is a known risk factor for breast carcinogenesis. In cells, estrogens, in particular estrone (E1) and 17β-estradiol (E2), can be converted to catecholestrogens (CEs) which may be oxidized to form CE-semiquinones and CE-quinones that are capable of binding to DNA to induce mutations, followed by carcinogenesis. Whether the body is equipped with protective mechanisms against potentially harmful CEs, therefore, is an important issue. The present study was designed to examine the role of sulfation in the metabolism of CEs. MCF-7 breast cancer cells and MCF 10A human mammary epithelial cells were metabolically labeled with [35S]sulfate in the presence of individual CEs. Analysis of the labeling media showed the generation and release of exclusively [35S]sulfated 2-methoxy-E1 or [35S]sulfated 2- or 4-methoxy-E2 by cells labeled in the presence of 2-OH-E1 or 2- or 4-OH-E2. Whereas both [35S]sulfated 4-methoxy-E1 and [35S]sulfated 4-OH-E1 were detected in the labeling media of cells labeled in the presence of 4-OH-E1. These results indicated a concerted action of catechol-O-methyltransferase (COMT) and the cytosolic sulfotransferase (SULT) enzyme(s) in the metabolism of CEs. Enzymatic assays revealed that, five (SULT1A1, SULT1A2, SULT1A3, SULT1C4, and SULT1E1) of eleven known human SULTs tested could use CEs and methoxyestrogens (MEs) as substrates, with SULT1E1 displaying the strongest sulfating activity.