Long-term total parenteral nutrition (TPN) is known to be associated with cholestasis and hepatic steatosis, which can be lethal in infants who cannot be fed orally. The present review focuses on the metabolic complications in the liver that may occur due to the excessive administration of fat-free TPN. We have recently developed an infant rat model of hepatic dysfunction and steatosis induced by overdose of fat-free TPN. In this model, plasma levels of liver enzymes in the fat-free TPN group were found to be significantly higher than in the other groups (i.e., the oral diet and fat-containing TPN groups). Pathological examination showed hepatomegaly and severe fatty changes without cholestasis in the liver of infant rats that received fat-free TPN. We clearly demonstrated that the addition of soybean oil emulsion to the TPN regimen prevented hepatic dysfunction and fatty changes. In the present review, we discuss the molecular mechanism of the hepatic dysfunction induced by fat-free TPN and the role of soybean oil fat emulsion in the TPN regimen. We also discuss the clinical implications of soybean oil-containing TPN solutions and point out the importance of including fat in the TPN regimen in order to prevent the hepatic abnormalities associated with the excessive administration of fat-free TPN.
A close relationship between rat liver regeneration and the concentration ratio of spermidine to spermine (spd : spm) was demonstrated by the oral administration of trans-4-methylcyclohexylamine (MCHA), a specific inhibitor of putrescine aminopropyltransferase. A decrease in recovery rate of remnant liver with MCHA, as a percentage index of remnant liver weight to body weight, correlated well with a decrease of the spd : spm value, with a correlation coefficient of 0.952 for the remnant livers on day 3 after partial hepatectomy. The decrease in recovery rate could be explained by a prolonged cell cycle based on the data of the proliferating cell nuclear antigen labelling index and mitotic cell index in both livers of day 2 and day 3 after partial hepatectomy. The results presented here will give a new aspect in the field of polyamine regulation to control cell growth in vivo.
Rat liver microsomal glutathione S-transferase (MGST1) is known to be activated by trypsin, however, it has not been clarified whether MGST1 is activated by a protease present in liver. In the present study we purified the MGST1 activating protease from liver microsomes and finally identified that the protease is hepsin, a type II transmembrane serine protease. When the protease was incubated with the purified MGST1 or liposomal MGST1 at 4 °C, MGST1 activity was increased 3—4.5 fold after 3—6 d. In electrophoretic and immunoblot analyses after the incubation of MGST1 with the protease MGST1 dimer and its degraded fragment were detected. These results suggest that the rat liver microsomal hepsin functions as MGST1 activating/degrading enzyme.
A base non-specific ribonuclease (RNase Bm2) was isolated from a green algae (Ulvophyceae, Bryopsis maxima) as a single band on SDS-PAGE, and its primary structure and enzymatic properties, including base specificity, were investigated. The amino acid sequence of RNase Bm2 was homologous to many RNase T2 family RNases, and their characteristic CAS sequences were also conserved. The molecular mass of RNase Bm2 was 24444 Da, and its optimal pH was 5.5. RNase Bm2 was a poly U preferential RNase, similar to RNase MC1 from bitter gourd. The base specificity of this RNase suggested that the base specificity of the B1- and B2-base binding sites of RNase Bm2 were G≥U>C≫A and U>G>C≫A, respectively. The estimated active site of RNase Bm2 was very similar to that of RNase MC1 from bitter gourds; however, a tyrosine residue at the B1-base binding site that is conserved for all RNase T2 family RNases was replaced by a tryptophan residue. Here we discuss the effect of this replacement on the base specificity of RNase Bm2 and the phylogenetic relationship of RNase T2 family enzymes.
As part of an ongoing investigation to find bioactive medicinal herbs exerting anti-inflammation activity, the effect of an ethanol extract from the parts of Ailanthus altissima (Simaroubaceae) was evaluated in both in vitro and in in vivo system. The ethanol extract of A. altissima (EAa) inhibited generation of the cyclooxygenase-2 (COX-2) dependent phases of prostaglandin D2 in bone marrow-derived mast cells (BMMC) in a concentration-dependent manner with an IC50 value of 214.6 μg/ml. However, this compound did not inhibit COX-2 protein expression up to a concentration of 400 μg/ml in the BMMC, indicating that EAa directly inhibits COX-2 activity. In addition, EAa inhibited leukotriene C4 production with an IC50 value of 25.7 μg/ml. Furthermore, this compound inhibited degranulation reaction in a dose dependent manner, with an IC50 value of 27.3 μg/ml. Ovalbumin (OVA)-sensitized mice were orally pretreated with EAa before aerosol challenges. EAa reduced the eosinophil infiltration into the airway and the eotaxin, IL-4, and IL-13 mRNA expression levels. These results suggest that the anti-inflammation activity of A. altissima in OVA-induced lung inflammation may occur in part via the down regulation of TH2 cytokines and eotaxin transcripts as well as the inhibition of inflammatory mediators.
We have investigated possible roles of intra-glucose supply on microsomal triglyceride (TG) transfer protein (MTP) in the secretion of TG-rich very low-density lipoprotein (VLDL) from the liver. Due to the activation of MTP, TG and apolipoprotein B (apoB) in the liver are assembled into VLDL and then the VLDL is transferred into the blood stream. High MTP activity can increase the release of VLDL into the blood stream, and this would lead high levels of TG and apoB in the blood. High MTP activity was found when the liver (or hepatocytes) contained a high level of total Ca2+ as a response of glucose administration. However, the MTP activity was reduced in response to the calmodulin antagonist N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide (W-7, Ki=25 μM), the intracellular Ca2+ chelator BAPTA-AM, and the extracellular Ca2+ chelator EDTA. These suggested that there might be a very close relationship between high MTP activity and high Ca2+ level in the liver by glucose administration. Glucose-derived hyperglycemic condition resulted from those elevations of TG and total cholesterol in the liver. This hyperglycemic phenomenon may be associated with the increase of TG and apoB levels in blood. The possibility for the regulation of VLDL formation in the liver and, further, those related circulatory diseases due to the excess of VLDL in the blood stream by controlling MTP activity in association with Ca2+ was investigated.
AgK114 is a newly isolated membrane-associated protein which is expressed on keratinocytes. Its expression is restricted to dermal sheath cells near sebaceous glands in normal skin. However, it is transiently induced by UV exposure or injury stimulation (Tatefuji T. et al., Biol. Pharm. Bull., 27, 1742—1749, 2004). Thus, the expression pattern of AgK114 suggested its potential role in wound healing response. We report here that expression of AgK114 is induced in the initial 24 h at the edge keratinocytes during keratinocyte migration, followed by disappearance once epithelialization is completed in the murine excisional wound model. We also demonstrate that exogenous recombinant mouse AgK114FL promoted wound healing process. Mouse AgK114FL up-regulated pro-matrix-metalloproteinase-9, vascular endotherial growth factor, transforming growth factor-β, IL-6, and IL-1β production in the early stage of wound tissue. Moreover, mouse AgK114FL induced the matrix-metalloproteinase-9 activity of wound fibroblasts prepared from impaired skin in the presence of proinflammatory cytokines. These results suggest that the AgK114 participates in the wound response during the healing process, and promotes wound repair.
MicroRNAs (miRNAs) are endogenously expressed RNAs, 18—25 nucleotides in length, that repress protein translation through binding to target mRNAs. miRNAs have been implicated in many cellular processes including cell proliferation, differentiation, and death. Recently, let-7 miRNAs were found to regulate human RAS oncogene expression and to be often down-regulated in human lung tumors. In this study, we examined the expression of let-7 miRNAs in human colon cancer tumors and cell lines, with the result that 2 of 6 cases and 1 of 3 cell lines showed reduced expression of let-7. When let-7 low-expressing DLD-1 human colon cancer cells were transfected with let-7a-1 precursor miRNA, which is located at chromosome 9q22.3, the cells underwent significant growth suppression. At that time, the levels of RAS and c-myc proteins were lowered after the transfection, whereas the levels of both of their mRNAs remained almost unchanged. These findings suggest the involvement of let-7 miRNA in the growth of colon cancer cells. Thus, miRNAs might provide a basis for novel RNA anti-cancer agents.
Lysophosphatidylcholine (LPC), formed during low-density lipoprotein (LDL) oxidation and located within atherosclerotic plaques, regulates a variety of cellular functions, some of which could be construed to promote atherosclerotic lesion development, including vascular muscle cell proliferation, monocyte attraction, and endothelial cell apoptosis. We have previously reported that the synthetic peptide derived from Asp-hemolysin, named P-21, inhibits oxidized LDL (OxLDL)-induced macrophage proliferation through binding of P-21 to OxLDL. In this study, to clarify the interaction between P-21 and LPC as a typical lipid moiety of OxLDL, we examined the influence of P-21 on LPC-induced apoptosis in human umbilical vein endothelial cells (HUVECs). Based on flow cytometric analysis, using annexine V-fluorescein isothiocianate and propidium iodide as probes to assess apoptosis, LPC induced the apoptosis of HUVECs, and P-21 significantly inhibited this activity by 82.4%. Furthermore, dissociation-enhanced lanthanide fluorometric immunoassay indicated that LPC inhibited the binding of P-21 to OxLDL in a dose-dependent manner. A 50% inhibition dose was estimated to be 4.65 μM of LPC. These results suggest that P-21 inhibits LPC-induced HUVEC apoptosis through binding of P-21 to LPC.
The roles of metalloprotease (VvpE) and catechol-siderophore (vulnibactin) in the uptake of iron from human transferrins by Vibrio vulnificus have been determined using different experimental conditions and methods. Therefore, in this study, we attempted to elucidate the roles of VvpE and vulnibactin using the same methods and experimental conditions, in an in vitro and a human ex vivo system, and in accordance with the molecular version of Koch's postulates. Neither vvpE mutation nor in trans vvpE complementation affected vulnibactin production, iron-assimilation from human holotransferrin (HT), and bacterial growth in a HT-containing deferrated Heart-Infusion medium (HT-DF-HI) or a HT-containing cirrhotic ascites (HT-CA). In contrast, the mutation of fur gene encoding Fur, a repressor regulating expression of the vulnibactin-mediated iron-uptake system, derepressed vulnibactin production, and facilitated iron-assimilation from HT and bacterial growth in HT-DF-HI or HT-CA. The mutation of vis gene encoding isochorismate synthase required for vulnibactin synthesis abolished vulnibactin production, iron-assimilation from HT and bacterial growth in HT-DF-HI or HT-CA. These results demonstrate that vulnibactin is essentially required for iron-assimilation from transferrin, and that VvpE has no direct effect on facilitating vulnibactin-mediated iron-assimilation from transferrin in vitro or in a human ex vivo system.
The sensitivity of Candida albicans to antifungal drugs when cultured under aerobic and anaerobic conditions was measured. Ciclopirox olamine and siccanin were more effective under aerobic than under anaerobic conditions. Terbinafine, neticonazole and amphotericin B showed the same antifungal activity under both aerobic and anaerobic conditions. None of these antifungal activities were affected by the pH conditions. Terbinafine inhibited the elongation of hyphae, while neticonazole and amphotericin B induced proliferation of the yeast form. The expression of RAS1, EFG1 and CPH1 mRNAs was inhibited by these drugs. These results suggested that the inhibition of hyphal formation might be caused by disruption of the RAS1-signal pathway.
Hyphal growth of Candida albicans was observed at neutral condition, whereas the yeast growth was increased below pH 5. Eight out of 12 strains of C. albicans grow in hyphal form at pH 7, and hyphal formation was inhibited in all strains at pH 4. The addition of GMP, an alternative oxidase (AOX) activator, induced the hyphal growth at pH 4. Although C. albicans grew in hyphal form in pH 7, SHAM, an AOX inhibitor, enhanced the yeast proliferation at this pH. The relative expression level of RAS1 mRNA was higher at pH 7 than at pH 4, indicating that the hyphal formation signal was defective under acidic conditions. Based on these findings, we concluded that AOX-RAS1 signal transduction is the main pathway of hyphal formation of C. albicans, and that the signal was controlled by pH condition.
The interaction of anti-prion compounds and amyloid binding dyes with a carboxy-terminal domain of prion protein (PrP121—231) was examined using surface plasmon resonance (SPR) and compared with inhibition activities of abnormal PrP formation in scrapie-infected cells. Most examined compounds had affinities for PrP121—231: antimalarials had low affinities, whereas Congo red, phthalocyanine and thioflavin S had high affinities. The SPR binding response correlated with the inhibition activity of abnormal PrP formation. Several drugs were screened using SPR to verify the findings: propranolol was identified as a new anti-prion compound. This fact indicates that drug screenings by this assay are useful.
The sympathetic nerve activity plays an important role on the renal function through the vasoactive system and the renin-angiotensin system. Although interest in the renal protective effects of anti-sympathetic agents has been increased, there are not enough data to clarify this efficiency. Therefore, we investigated the effects of L/N-type calcium channel antagonist, cilnidipine on progressive renal injury in Dahl salt-sensitive (Dahl S) rats. Male Dahl S rats (6 weeks of age) were fed a high salt (4% NaCl) diet. They were divided into groups with similar blood pressure at 12 weeks of age and they received vehicle (n=7) or cilnidipine (30 mg/kg/d as food admix, n=9) for 8 weeks. Cilnidipine treatment suppressed the increase in systolic blood pressure. Although urinary protein excretion was not influenced, cilnidipine inhibited the increase in blood urea nitrogen and decrease in creatinine clearance. Histological investigation revealed that progression of gromerular sclerosis was inhibited in cilnidipine treatment group. Of notes, cilnidipine reduced plasma norepinephrine level and plasma rennin activity compared with vehicle-treated Dahl S rats. These data indicated that cilnidipine has suppressive effects against progressive renal injury in Dahl S rats. This effect is not only explained by the L-type calcium channel blocking action that lowered blood pressure, but also partially explained by the N-type calcium channel blocking action that lead to suppression of the sympathetic nerve activity and renin-angiotensin system.
The ethanolic extracts from the rhizome of Curcuma longa L. (turmeric), possesses a wide variety of biological activities related to the treatment and prevention of affective disorders. To study their antidepressant effects, the impacts of chronic mild stress (CMS) and of the subsequent administration of ethanolic extracts of C. longa were investigated. Male Sprague–Dawley rats subjected to the CMS procedure demonstrated increased serum interleukin-6 and tumor necrosis factor-alpha levels, as well as a reduction of natural killer cell activity in splenocytes. In addition, CMS-treated rats exhibited levated corticotropin-releasing factor in serum and medulla oblongata and cortisol levels in serum, with no significant change in serum adrenocorticotropin hormone levels. The preferential behavior of reduction in sucrose intake was also observed. These findings indicate that the alterations in immune and hypothalamic-pituitary-adrenal (HPA) axis systems could participate in the behavioral response to the CMS procedure in animals. Administration of ethanolic extracts of C. longa largely reversed the above effects. These results demonstrate the antidepressant-like activity of ethanolic extracts of C. longa in the rat CMS model of depression, at least in part by improving the abnormalities in immune and the HPA axis functions.
Puerarin is a major effective ingredient extracted from the traditional Chinese medicine Ge-gen (Radix Puerariae, RP). Recently, puerarin has been used to treat patients with coronary artery diseases (CAD). However, the mechanisms of puerarin on coronary artery diseases are still not very clear. In this study, we investigated the role of puerarin on angiogenesis in the non-ischemic and ischemic myocardium. We found that puerarin (120, 60 mg/kg, i.p.) could reduce infarct area in the heart of rat with myocardial infarction (MI). Puerarin (120 mg/kg) induced angiogenesis in the non-ischemic and ischemic myocardium, which was one of the mechanisms of curing coronary artery diseases. The gene expression or activation of vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1α (HIF-1α) and endothelial nitric oxide synthase (eNOS) that correlated with angiogenesis were also induced by puerarin. From these results, we suggested that puerarin may induce therapeutic angiogenesis in myocardium of rat with MI. The mechanism may be that puerarin can induce VEGF and eNOS expression.
20(R)-Ginsenoside Rh2 is isolated from Chinese traditional ginsengs with main antitumor effects. To support its pharmacokinetic study which was essential for the pre-clinical research for new drug development, in this paper, 20(R)-Rh2 plasma protein binding was assessed in vitro at four concentration levels (50, 100, 200, 400 ng/ml) both in rat and human plasma using equilibrium dialysis and followed by LC-MS analysis. The method was optimized against some influencing factors during both experimental procedures. And it was validated to be specific, sensitive, accurate, precise and of satisfactory recovery. The results showed the binding fractions were about 70% for rats and 27% for human within four concentration levels. It exhibited a significant species difference between human and rats for the plasma protein binding of 20(R)-Rh2.
Stroke is a third leading cause of death and oxygen free radicals have been shown to be involved in its pathophysiology. In the present study, we have investigated neuroprotective potential of trolox, a free radical scavenger in bilateral carotid arteries occlusion (5 min) model of global cerebral ischemia in Mongolian gerbils. Gerbils were treated with trolox (3, 10 or 30 mg/kg, i.p.) 30 min prior to occlusion. There was a significant increase in neurological symptoms and locomotor activity in ischemic animals as compared with the sham-operated animals. These effects were attenuated by trolox 30 mg/kg, i.p. Significant increase in the number of the surviving neurons in the hippocampal CA1 pyramidal region was observed in ischemic animals treated with trolox 30 mg/kg, i.p. There was significant increase in the level of malondialdehyde (MDA) in ischemic animals indicating oxidative stress. Elevated levels of MDA in ischemic animals (25.79±3.34 μM/mg of protein) were reduced (16.43±3.32 μM/mg of protein) and (8.98±0.89 μM/mg of protein) by trolox 10 and 30 mg/kg, i.p., respectively. This study demonstrates the neuroprotective potential of trolox in global cerebral ischemia in gerbils.
Aged garlic extract (AGE) has recently received attention as a potent anti-fatigue agent. The principal aim of this study was to elucidate the mechanism responsible for the ameliorating effect of AGE on physical fatigue in rats caused by repeated endurance exercise on a mechanical treadmill apparatus. Rats were subjected to endurance exercise 5 times per week for 4 weeks. AGE at a dosage of 2.86 g/kg was administrated to rats 30 min before every exercise. Succinate dehydrogenase (SDH) activity in the gastrocnemius and soleus muscles and superoxide dismutase (SOD) activity, nitric oxide (NO) metabolites, and lactic acid concentration in plasma were evaluated as biomarkers of physical fatigue. SDH activity was increased 2—4-fold by repeated endurance exercise in comparison with unexercised (intact) rats, and AGE further up-regulated this activity by 40%. SOD activity was increased 5-fold, whereas AGE maintained it at a level equivalent to that in intact rats. Levels of NO metabolites were slightly decreased, whereas AGE enhanced them 2-fold. Lactic acid concentration was not changed in any of the groups. These results indicate that AGE may facilitate the turnover of aerobic glucose metabolism, attenuate oxidative stress, and promote oxygen supply based on vasodilation, suggesting that AGE ameliorates the various impairments associated with physical fatigue.
The pharmacokinetics of arsenic species in a Japanese patient with relapsed acute promyelocytic leukemia (APL) treated with arsenic trioxide at a daily dose of 0.08 mg/kg was investigated. After achieving complete remission on Day 35 during the induction therapy of arsenic trioxide, we collected the serum and urine samples on Days 4 and 5 during the consolidation therapy of arsenic trioxide. The concentrations of inorganic arsenic and the methylated metabolites in serum and urine were measured by HPLC/ICP-MS. The patient restricted taking the seafood for 3 d before the start of administration and during the sampling period in order to avoid the influence of arsenic derived from seafood. Arsenite (AsIII), methylarsonic acid (MMAsV), and dimethylarsinic acid (DMAsV) were detected in serum and urine. The total concentration of AsIII, MMAsV and DMAsV in serum ranged from 18 to 41 μg/l (240—547 nM) during 24 h on Day 4. The amount of total arsenic (AsIII+MMAsV+DMAsV) in urine was 4464 μg/d on Day 4. These results suggest that not the micro-molar but the nano-molar order of arsenic in serum is sufficient to produce the therapeutic effect on APL cells.
In the present study, we evaluated the in vitro and in vivo anti-angiogenic and anti-tumor activities of 2′-hydroxy-4′-methoxychalcone (HMC). HMC decreased angiogenesis in both chick embryos in the chorioallantoic membrane assay and basic fibroblast growth factor (bFGF)-induced vessel formation in the mouse Matrigel plug assay. This compound also reduced the proliferation of calf pulmonary arterial endothelial cells and was found to possess relatively weak gelatinase/collagenase inhibitory activity in vitro. HMC, when administered subcutaneously at the dose of 30 mg/kg for 20 d to mice implanted with murine Lewis lung carcinoma, caused a significant inhibition of tumor volume by 27.2%. Intraperitoneal (i.p.) treatment at the same dosage for 10 d to ICR mice bearing sarcoma 180 caused a significant suppression in tumor weight by 33.7%. Taken together, out data demonstrate that the anti-angiogenic activities of HMC might be due to anti-proliferative activity under inhibition of the induction of COX-2 enzyme. Furthermore, the results suggest that the potent anti-angiogenic activity of HMC seems to be the possible mechanism of action in these animal models of solid tumors.
Microsomal enzyme inducers are known to influence the expression of many transporter proteins and mRNA. In this study, we examined the effects of microsomal enzyme inducers on the mRNA expression of Breast Cancer Resistance Protein (BCRP) and Multidrug Resistance Associated Protein 2 (MRP2) in BALB/c mice. mRNA expression in liver, duodenum, jejunum and ileum was examined in mice, which were treated with microsomal enzyme inducers–aryl hydrocarbon receptor (AhR) ligands 3-methylcholanthrene (3-MC) and pregnane-x-receptor (PXR) ligand pregenolone-16α-carbonitrile (PCN) and compared with control vehicle. The results suggested that the expression level of bcrp mRNA in the ileum was twice that in the liver, duodenum and jejunum using both semi quantitative PCR and Real-time PCR. Mrp2 mRNA was significantly increased by both PCN and 3-MC treatment. In contrast, bcrp mRNA expression was not significantly affected by these inducers. In summary, this study demonstrated that the expression of mrp2 mRNA is regulated by PCN and 3-MC, however, bcrp mRNA expression was not significantly affected by PCN and 3-MC.
We examined the effects of perinatal stress on the emotion-related behavior of the mouse during their adolescent period. Firstly, we applied the sound noise and/or the forced swim stress to the maternal pregnant mice in the pregnant mice at 10 to 18 d gestation. The stress applied during the fetal period did affect neither the spontaneous locomotor activity of the offspring mice in a new environment at an age of 4 weeks, nor those sound-induced changes in the locomotor activity. Secondly, we applied the stress to the neonatal mouse during the late lactation period, 14 to 18 d after birth. The mice that underwent the forced swim stress accompanied by the sound noise stress showed a significant reduction of the locomotor activity. On the other hand, the mice that underwent the forced swim stress during the lactation period showed a significant increase in the locomotor activity after the stimulation by the sound noise. Lastly, we applied the stress to the neonatal mouse immediately after the weaning period, 21 to 25 d after birth. The spontaneous locomotor activity of the mice was not changed compared to that of the non-stressed group. Thus, it was found that the stress applied to the mice during the lactation period, thought to be the critical period of mouse brain development, selectively influenced the emotion-related behavior in the subsequent adolescent period. These results suggested that second postnatal week may be the critical period for establishing proper behavioral responses to emotional stress in the adolescent mouse.
Two known flavonoids were isolated from a tropical medicinal plant, Hyptis fasciculata (Labiatae), found in Brazil. Flavonoids were identified as cirsilineol (1) and cirsimaritin (2) by spectroscopic means and were exhibited potent antibacterial activity against Helicobacter pylori, and cirsilineol (1) had weak antibacterial activity against Escherichia coli and Salmonella enteritidis. Following up on the relationship between anti-H. pylori activity and flavonoids with methoxy groups, several methoxy flavonoids were evaluated for proliferation of H. pylori.
Increased incidence of heart disease is reported in patients with diabetes. To elucidate a molecular profile of expressed genes during the progression of diabetes, a cDNA array was screened in the hearts of mice treated with streptozotocin (200 mg/kg, i.v.). Among the genes investigated, the plasma type glutathione peroxidase, GPX-3, was predominantly up-regulated in diabetic mice compared with control mice. In northern blot analysis, a significant increase in GPX-3 expression was observed as early as 5 d after the induction of hyperglycemia. On day 21, a nearly three-fold induction was demonstrated. Daily administration of insulin (0.2 U/d, s.c.) for 21 d almost completely abolished the increase in GPX-3 mRNA in streptozotocin-treated mice, suggesting that the expression level of the GPX-3 gene was dependent on insulin and serum glucose. Increased GPX-3 may play a significant role in protecting cardiomyocytes from oxidative stress caused by hyperglycemia.
Ginkgetin, a biflavonoid from Ginkgo biloba leaves (Ginkgoaceae), was previously demonstrated to inhibit phospholipase A2 and to suppress proinflammatory gene expression such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase. In this study, the effects of ginkgetin were examined on an animal model of chronic skin inflammation and proinflammatory gene expression. When topically applied to ICR mouse ear, ginkgetin (20—80 μg/ear/treatment) inhibited ear edema (22.8—30.5%) and prostaglandin E2 production (30.2—31.1%) induced by multiple treatment of 12-O-tetradecanoylphorbol-13-acetate (TPA) for 7 consecutive days. By histological comparison, ginkgetin was also found to reduce epidermal hyperplasia. The expression of proinflammatory gene, interleukin-1β, was suppressed by ginkgetin. From the results, it is suggested that ginkgetin may be beneficial against chronic skin inflammatory disorders like atopic dermatitis.
Malaria is one of the most life-threatening infectious diseases worldwide and claims the millions of peoples life each year. The appearance of drug-resistance Plasmodium falciparum has made the treatment of malaria increasingly problematic, and thus, it is a dire need to search the new alternatives of current drugs. In the present study, 44 cassane- and norcassane-type diterpenes isolated from Caesalpinia crista of Myanmar and Indonesia were evaluated for their antimalarial activity against the malaria parasite Plasmodium falciparum FCR-3/A2 clone in vitro. Most of the tested diterpenes displayed antimalarial activity, and norcaesalpinin E (28) showed the most potent activity with an IC50 value of 0.090 μM, more potent than the clinically used drug chloroquine (IC50, 0.29 μM). Based on the observed results, a structure–activity relationship has been established.
This study was undertaken to produce the clinical merits of two natural antinociceptive anti-inflammatory triterpenoids which synthetic anti-inflammatory drugs do not have. The triterpenoid glycoside niga-ichigoside F1 (NIF1) and its aglycone 23-hydroxytormentic acid (23-HTA), which were isolated from the unripe fruits of Rubus coreanus (Rosaceae), reduced rheumatoid arthritis (RA) factor and C-reactive protein (CRP) factor in Freund's complete adjuvant reagent-induced rats, suggesting that these two triterpenoids had an anti-rheumatic effect. It was also shown that treatment with NIF1 or 23-HTA reduced gastric lesion extent, acidity and total gastric acid output induced by EtOH plus sodium salicylate in a gastric secretion test. Moreover, 23-HTA had a greater effect than the glycoside, NIF1. To clarify the anti-gastropathic mechanism of these two compounds, their free radical scavenging activities in the gastric mucosa were examined in a rat EtOH–sodium salicylate-induced gastropathy model. The two compounds significantly increased superoxide dismutase and glutathione peroxidase activities, indicating that the healing effects of NIF1 and 23-HTA against gastropathy are associated with free radical scavenging enzyme activities. These results support the notion that the long-term administration of NIF1 or 23-HTA should overcome the adverse effects of synthetic anti-inflammatory drugs.
The anti-inflammatory and anti-nociceptive effects and sedative activities of the ethyl acetate fraction of Cynanchum paniculatum (EACP) were evaluated in mice and rats by acetic acid-induced vascular permeability, arachidonic acid-induced paw edema, cotton pellet-induced granuloma formation, formalin-induced licking time, acetic acid-induced writhing response, and pentobarbital-induced sleeping time. EACP at a dose of 40 mg/kg significantly exhibited anti-inflammatory activities on acetic acid-induced vascular permeability, arachidonic acid-induced paw edema, and the late phase of formalin-induced licking time. Moreover, it showed anti-nociceptive effects on acetic acid-induced writhing responses and significant sedative effects on pentobarbital-induced sleeping time. The results demonstrated that the anti-nociceptive effects are apparently related to the sedative effects of EACP. These results support the use of Cynanchum paniculatum in relieving inflammatory pain.
Inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) play a key role in the inflammatory processes. Improper overproduction of NO and prostaglandins by both enzymes are also believed to be involved in the pathogenesis of certain human cancers. Crude extracts of Selaginella tamariscina are used as an oriental medicine, which has been reported to inhibit the production of proinflammatory cytokines and cause cell cycle arrest. We isolated 2′,8″-biapigenin from S. tamariscina and investigated whether it modulates iNOS and COX-2 expressions in Raw264.7 macrophages stimulated with lipopolysaccharide (LPS). We found that 2′,8″-biapigenin blocked the transactivations of iNOS and COX-2 genes via the inactivation of nuclear factor-κB by preventing the nuclear translocation of p65. Hence, it may be possible to develop S. tamariscina extracts or 2′,8″-biapigenin as a useful agent for cancer chemoprevention or for the treatment of inflammatory diseases.
During screening for inhibitors of lipid droplet accumulation in mouse peritoneal macrophages, two coumarins identified as decursin and decursinol angelate were isolated from the roots of Angelicae gigantis. The cellular molecular target of these inhibitors in macrophages was studied. Decursin and decursinol angelate inhibited cholesteryl ester (CE) synthesis with IC50 values of 9.7 and 10.1 μM, respectively, whereas they enhanced triacylglycerol (TG) synthesis. Lysosomal metabolism of cholesterol to CE was inhibited by the compounds, indicating that the site of inhibition is one of the steps between the exiting of cholesterol from the lysosomes and CE synthesis in the endoplasmic reticulum. Therefore, acyl-CoA:cholesterol acyltransferase (ACAT) activity in the microsomal fractions prepared from mouse macrophages was studied, and the results showed inhibition of this activity by decursin and decursinol angelate with IC50 values of 43 and 22 μM, respectively. Thus, it was concluded that the compounds inhibit macrophage ACAT activity to decrease CE synthesis, leading to a reduction of lipid droplets in macrophages.
During our ongoing efforts to identify bioactive natural products with anti-inflammatory activity, we produced an extract from Ginkgo biloba (GBB) which contains higher levels of the active principles terpene and biflavonoid than EGb, the standard commercially available extract. In the present study, we examined and compared the effects of these two extracts on lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production by the RAW 264.7 macrophage cell line. Our data indicate that GBB is a more potent inhibitor of NO and PGE2 production than EGb 761, and it also significantly decreased tumor necrosis factor (TNF)-α release. Consistent with these observations, the protein and mRNA expression levels of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) were found to be inhibited by GBB in a dose-dependent manner. Furthermore, GBB inhibited the LPS-induced DNA binding activity of nuclear factor-κB (NF-κB), which was associated with the prevention of IκB degradation, and subsequently with decreased p65 protein level in the nucleus. These results suggest that GBB inhibits LPS-induced iNOS, COX-2 and TNF-α expressions through the down-regulation of NF-κB-DNA binding activity.
An extract of heat-processed Achyranthes fauriei roots showed more potent cytotoxic activity against human hepatoma SK-Hep-1 cells than that of the crude plant. Employing a bioassay-linked HPLC-ELSD (high performance liquid chromatography-evaporative light scattering detector) method, followed by silica gel column chromatography, a cytotoxic triterpenoid saponin, chikusetsusaponin IVa was isolated. It is contributive to the increased cytotoxic activity of the heat-processed. The amount of chikusetsusaponin IVa from the roots of Achyranthes fauriei was significantly increased after heat-processing.
The objective of the present study was to investigate the effects of saponin fraction from anomalous fruits of Gleditsia sinensis (SFGS) on picryl chloride-induced delayed type hypersensitivity (PC-DTH) and functions of T lymphocytes and macrophages in mice. SFGS (100, 200 mg/kg), orally administered during either sensitization stage or effector stage, produced remarkable inhibition of PC-DTH. In vitro, SFGS (1, 2, 4 μg/ml) concentration-dependently attenuated concanavalin A (Con A)-elicited mouse splenocyte proliferation and interleukin 2 (IL-2) production. At concentrations of 10 and 20 μg/ml, SFGS inhibited lipopolysaccharide (LPS)-induced production of nitric oxide and interleukin 1β (IL-1β) of mouse peritoneal macrophages. The findings indicate that SFGS attenuates PC-DTH in mice, which is probably mediated by preventing proliferation and differentiation of T cells during the sensitization stage and suppressing activation of macrophages during the effector stage.
Aquaporin 3 (AQP3), a membrane protein, is known to permeabilize water and other small molecules such as glycerol and urea and is localized in the bowel, skin, kidney, and erythrocytes. Since glycerol is a nutrient and serves as a source material in glycolytic metabolism, absorption of glycerol in the gastrointestinal tract may be under some control. Therefore we first investigated whether insulin regulating the glycolytic pathway took part in glycerol transport through AQP3 in the gastrointestinal tract and found that insulin significantly suppressed mRNA and protein expressions of AQP3 in Caco-2 cells. The antidiabetic drugs troglitazone and tolbutamide were also observed to suppress significantly AQP3 expression, but the biguanides metformin and buformin did not induce such suppression. Epinephrine was found to increase expression of AQP3, although glucagon showed no change of expression. Wortmannin and rapamycin were demonstrated to deactivate suppression of AQP3 expression by insulin and troglitazone, suggesting that the signal transducers, phosphoinositide 3 kinase (PI3K) and the mammalian target of rapamycin (mTOR), are involved in the signal pathway for regulating transcription of AQP3.
Human oligopeptide transporter (hPEPT1) translocates di/tri-peptide by coupling to movement of proton down the electrochemical gradient. This transporter has the characteristics that the pH-profile of neutral dipeptide transport shows a bell-shaped curve with an optimal pH of 5.5. In the present study, we examined the reason for the decrease in the acidic region with hPEPT1-transfected CHO cells stably oeverexpressing hPEPT1 (CHO/hPEPT1). The pH profile of the transport activity vs. pH was measured in the presence of nigericin/monensin. Under this condition, the inwardly directed proton concentration gradient was dissipated while the membrane potential remained. As pH increased the activity increased, and the Henderson–Hasselbalch equation with a single pKa was fitted well to the activity curve. The pKa value was estimated to be 6.7±0.2. This value strongly suggests that there is a key amino acid residue, which is involved in pH regulation of transport activity. To identify the key amino acid residue, we examined the effects of various chemical modifications on pH-profile of the transport activity. Modification of carboxyl groups or hydroxyl groups had no significant influence on the pH-profile, whereas a chemical modification of histidine residue with diethylpyrocarbonate (DEPC) completely abolished the transport activity in CHO/hPEPT1 cells. On the other hand, this abolishment was almost prevented by the presence of 10 mM Gly-Sar. This protection was observed only in the presence of the substrate of hPEPT1, indicating that the histidine residue is located at the substrate recognition site. The pH-profile of the transport activity in CHO/hPEPT1 cells treated with DEPC in the presence of 10 mM Gly-Sar also showed a bell-shape similar to that in non-treated CHO/hPEPT1 cells. These data stressed that the histidine residue located at or near the substrate binding site is involved in the pH regulation of transport activity.
The biguanides metformin and buformin, which are clinically used for diabetes mellitus, are known to improve resistance to insulin in patients. Biguanides were reported to cause lactic acidosis as a side effect. Since the mechanism of the side effect still remains obscure, we have examined genes whose expression changes by treating HepG2 cells with buformin in order to elucidate the mechanisms of the side effect. A subtraction cDNA library was constructed by the method of suppressive subtractive hybridization and the screening of the library was performed with cDNA probes prepared from HepG2 cells treated with or without buformin for 12 h. The expression of the gene and the protein obtained by the screening was monitored by real-time RT-PCR with specific primers and Western blotting with specific antibody. The amounts of ATP and NAD+ were determined with luciferase and alcohol dehydrogenase, respectively. We found that expression of the glyceraldehyde 3-phosphate dehydrogenase (GAPD) gene was suppressed by treating HepG2 cells with 0.25 mM buformin for 12 h as a result of the library screening. The decrease in the expression depended on the treatment period. The amount of GAPD protein also decreased simultaneously with the suppression of the gene expression by the treatment with buformin. The amount of ATP and NAD+ in the HepG2 cells treated with buformin decreased to 10 and 20% of the control, respectively. These observations imply that the biguanide causes deactivation of the glycolytic pathway and subsequently the accumulation of pyruvate and NADH and a decrease in NAD+. Therefore, the reaction equilibrium catalyzed by lactate dehydrogenase leans towards lactate production and this may result in lactic acidosis.
The tumoricidal and apoptosis-inducing activities of 5-fluorouracil (5-FU) have been demonstrated in experimental and clinical investigations. Clinically, the 5-FU suppository form has been widely adopted for its advantages of less systemic toxicity, higher local tissue concentrations, and reduced first-pass effect. In this study, we investigated the feasibility of rectal administration of 5-FU suppository based on poloxamer 188 (P188) and propylene glycol (PG) and its anticancer effect on the murine experimental cancer models. The rectal suppository was made with 70% P188 and 30% PG, which was a solid phase at room temperature and instantly melted at physiological temperature. The treatment with the 5-FU suppository was more effective than the oral route in decreasing the volume of rectal cancer in mice. In addition, the survival rate of the mice with rectal cancer was higher in the group treated with the 5-FU suppository than in the group treated with 5-FU orally. Furthermore, in mice skin cancers induced by inoculation of murine CT-26 colon carcinoma cells, the anticancer effect of 5-FU was significantly enhanced by the rectal administration of the suppository than by oral treatment. Taken together, the results suggest that a poloxamer gel system with 5-FU/P188/PG is an effective rectal dosage form for the treatment of both rectal and non-rectal cancers.
2-Methoxyestradiol (2-ME), an endogenous metabolite of 17β-estradiol, induces the intracellular accumulation of superoxide anion (O2·−) and buthionine sulfoximine (BSO) is an inhibitor of glutathione (GSH) synthesis. We have examined the combination anticancer effect of 2-ME and BSO accompanied with hydrogen peroxide (H2O2). 2-ME inhibited cell growth in renal carcinoma cell lines (ACHN and ACVB) accompanied by an increase in the intracellular contents of GSH. The combination of 2-ME, BSO and H2O2 showed a significant antiproliferation effect in both ACHN and ACVB. The intracellular levels of reactive oxygen species (ROS) with a combination with 2-ME and H2O2 in ACHN and ACVB pretreated with BSO were markedly increased, which may have contributed to the potential antiproliferative action.
Transdermal nicotine patch (TNP) contains approximately 16.6 and 24.9 mg of nicotine per 20 and 30 cm2 (TNP-20 and TNP-30). The aims of the study are to investigate linearity of nicotine pharmacokinetics after single application of different strengths of TNP and to directly compare plasma nicotine concentrations with those during cigarette smoking. Twelve healthy Japanese male smokers were randomly allocated to 1 of 2 cohorts consisting of 6 subjects each. Cohort 1 subjects received 1 sheet of TNP-20 (TNP-20×1) in period 1, and 2 sheets of TNP-20 (TNP-20×2) in period 3. Cohort 2 subjects were received 1 sheet of TNP-30 (TNP-30×1) in period 2, and smoked a total of 12 cigarettes at 1 h intervals in period 4. Each TNP was applied to the upper arm for 16 h. After TNP-20×1 or TNP-20×2 treatment in cohort 1, the amount of nicotine delivered from TNP (Dose) was proportional to surface area of TNP. Cmax and AUC of nicotine increased with the surface area (Dose), and tmax, t1/2, CL/F and percentage of dose excreted in urine were almost the same between both treatments. These suggest the linear pharmacokinetics of nicotine in proportion to the surface area and Dose following single application of TNP in identical subjects. In cohort 2, the plasma nicotine concentrations after TNP-30×1 treatment were approximately half those just before each smoking.
W39F, F52Y, S98G, S98A, and S98C mutants of the neocarzinostatin apoprotein (apo-NCS) were newly prepared and investigated their physicochemical properties. The circular dichroism (CD) spectra of F78W, F52Y, S98A, S98G, S98C were superimposable with that of wild type 1R49 protein although the minor spectral change seemed to be in the ellipticity of W39F. The results suggest that position 52, 78, and 98 involving natural chromophore binding do not play a major role in the inducing overall structural changes of the protein. Conversely, the position 39 would be affected slightly. Ethidium bromide (EtdBr) binding to mutants was also evaluated by the monitoring of total fluorescence intensity and fluorescence polarization (FP). The observed dissociation constant in the FP study was 4.4 μM for wild type, 2.2 μM for S98A, 1.3 μM for S98G, 9.7 μM for S98C, respectively. When S98G and F52Y, the calculated maximum change of the total fluorescence intensity was increased, suggesting that the EtdBr binding to S98G or F52Y were slightly improved compared with the wild type. Then, a total of 14 amino acids randomly substituted phage displayed library of apo-NCS was successfully prepared, because substitution of the amino acid structured the chromophore-binding cavity were not change the overall structural features. The phages which bound glycyrrhetic acid conjugated bovine serum albumin were enriched from this library using phage display technique as the pilot experiments. Although more precision investigation still needs, it should be possible to select variants that have new functions not found in nature.
CD14 is membrane-associating or free soluble glycoprotein which recognizes lipopolysaccharide (LPS) and is assumed to be involved in the onset of endotoxin shock. There are some reports suggesting the relationship between increased expression of CD14 in infectious or inflammatory diseases. However, little has been reported concerning the soluble CD14 (sCD14) level, especially in mice. In this study, we measured the plasma level of sCD14, TNF-α and IL-6 in the iota-carrageenan (CAR)-primed endotoxin shock model in addition to the D-galactosamine (D-galN)-primed endotoxin shock model mice. It was confirmed that all mice were dead within 12 h after a higher dose of LPS-treatment in both animal models. The level of TNF-α, IL-6 and sCD14 significantly increased in the CAR-primed endotoxin shock model mice. However, the D-galN-primed endotoxin shock model mice showed only a slight increment of TNF-α and IL-6 level, and sCD14 was below the detectable level. In the examination using several doses of LPS in CAR-primed model mice, IL-6 and sCD14 were increased dependent on the LPS dose, but TNF-α remained at an almost equal level at any dose of LPS in this study condition. In conclusion, the production of TNF-α, IL-6 and sCD14 was significantly enhanced in the CAR-primed model mice, compared to the D-galN-primed model mice. Therefore, these data indicate the possibility that the sCD14 level did not increase consistently, even under a fatal condition in endotoxin shock. Also, CAR-primed endotoxin shock would be an important experimental model to examine the elevation mechanisms for sCD14 and IL-6 production.