A novel screening experiment, to find radioactive probes for non-invasive measurements of physiological functions in experimental animals, was tested using the in vivo multitracer analysis technique. The details of the efficiency of the detector settings used in the in vivo multitracer analysis technique were examined by both computer simulations and practical measurements. Multiple radioactive isotopes, i.e. multitracer, were prepared by irradiating a silver foil target with a heavy ion beam at the RIKEN ring cyclotron. After chemical separation of the silver target, the multitracer was finally dissolved in isotonic citrate buffer. The multitracer solution was intravenously injected into rats. Using a γ-ray detector equipped with a well-defined slit, the collimated γ-rays from the upper abdomen of living rats were measured. After correction of detection efficiencies, it was possible to compare the distribution of radioactive elements between two groups of rats different in body weight. The in vivo measurement showed that the tissue substantial volume of the selenium-deficient (SeD) rat liver increased compared to normal rats. The possibility of a functional estimation of tissue/blood volume for living rats was proposed based on the characteristic in vivo distribution of 74As, 83Rb and 103Ru.
C-Glucosides, in which sugars are attached to the aglycone by carbon–carbon bonds, are generally resistant to acid and enzyme hydrolysis. The C-glucosyl bond of mangiferin, a xanthone C-glucoside, was cleaved by anaerobic incubation with a human intestinal bacterium, Bacteroides sp. MANG, to give norathyriol. A cell-free extract obtained by sonication of B. sp. MANG demonstrated cleaving activity for mangiferin to norathyriol by adding NADH, diaphorase, and dithiothreitol. Both high molecular weight (>10 k) and low molecular weight (<10 k) fractions obtained from the cell-free extract were required for the activity. MnCl2 was necessary for the activity, but other metal ions were not. By purification of the high molecular weight fraction using DEAE-cellulose and Phenyl Sepharose column chromatography, two fractions, designated as proteins A and B, were separated and required for the activity. Neither protein A nor protein B alone showed any activity. This is the first report describing a C-glucosyl-cleaving enzyme from human intestinal bacterium that seems to involve a novel enzyme mechanism.
The stromal MC3T3-G2/PA6 (PA6) cells from mouse clavaria did not require insulin for differentiation into mature adipose cells, although insulin is well known to play a key role in adipocyte differentiation. Large lipid droplets were observed in the cytoplasm of PA6 cells, and mRNA expression of the adipose specific proteins (aP2, PPARγ, C/EBPα, FAS, GLUT4, leptin, and adiponectin) as differentiation markers appeared or increased clearly in the cells at 8 d after stimulation without insulin. In addition, the glycerol released from the cells (lipolysis) was increased in a concentration-dependent manner by isoproterenol. However, the isoproterenol-induced lipolysis in the cells was not influenced by treatment with insulin, although that was observed in extramedullary adipocytes, 3T3-L1 cells. On the other hand, the 2-deoxy-D-[1-3H]glucose uptake in differentiated PA6 cells also increased by insulin, as shown in other adipose cells. In the cells, insulin induced the phosphorylation of extracellular signal-regulated kinases (Erks), Akt at Ser 473 and ribosomal p70 S6 protein kinase (p70 S6K) at Thr 389, and the insulin-induced 2-deoxy-D-[1-3H]glucose uptake was inhibited by pre-treatment with wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3K), or ML-9, an Akt inhibitor. These results suggest that the insulin signal for adipogenesis (lipogenesis) and lipolysis in bone marrow stroma PA6 cells differs from extramedullary adipocytes, such as 3T3-L1 cells.
So far it has proven difficult to identify a causative gene(s) or gene product initiating the events that lead to inflammation of the intestinal mucosa and, ultimately, progression to Crohn's disease (CD), an inflammatory bowel disease. However, gene transcripts identified in the intestine of trinitrobenzene sulfonic acid (TNBS)-treated mice might suggest a clue, and even represent candidate genes leading to inflammation and mucosal damage, and to subsequent fibrosis. In the present study, DNA microarray (13000 transcripts) methodology was applied to mucosal RNA extracted from TNBS-treated mice, some transcripts of which were validated via cDNA subtraction and RT-PCR analyses. Intestinal biopsy samples from CD patients were then analyzed using cDNA mini-array (1300 cDNAs), focusing on gene transcripts associated with cancer and immunity. Mini-array results revealed transcript changes similar and also dissimilar to those found from the DNA microarray analysis. These changes, previously known or newly identified, possibly occurring during the initial and progressive stages of inflammatory conditions may provide a clue to identify marker transcripts and/or targets for the development of future gene therapy.
Glucose transporter 2 (GLUT2) is tissue-specifically expressed in liver and kidney, and reduced in neoplastic hepatic lesions and in most hepatoma cell lines. Here we examined the involvement of epigenetic modifications in the regulation of GLUT2. Four CpGs in the GLUT2 promoter were undermethylated in GLUT2-expressing tissues. In isolated hepatocytes, GLUT2 expression declined and the promoter was methylated de novo. This de novo methylation occurred with a similar time-course in hepatocytes cultured in a high-glucose medium that induced GLUT2 expression, suggesting that de novo methylation can be induced independently of GLUT2 expression. GLUT2 was reactivated in hepatocytes following exposure to the methylation inhibitor 5-aza-2′-deoxycytidine (AzaC) but only after the methylation had occurred. In p53-deficient mouse liver, the CpGs were methylated de novo; the GLUT2 expression declined. The GLUT2 promoter was hypermethylated in Hepa1c1c7 cells, but expression could be rescued by AzaC. Thus, it is proposed that DNA methylation has an important role in the regulation of GLUT2 in mouse tissues and liver-derived cells.
The mammalian constitutive androstane receptor (CAR) is a transcription factor that participates in controlling the expression of xenobiotic metabolizing and transporting genes in response to xenobiotics in an organ-specific manner. In addition to the wild-type CAR (CAR WT) mRNA, mRNAs for five splice variants (SVs) could be detected in the liver of 7-week-old male Wistar rats by RT-PCR using primer pairs covering a full-length mRNA derived from 9 exons; insertion of 18 bp at the 5′-end of intron 8 with or without deletion of 3 bp from the 5′-end of exon 7 (CAR SV1 or SV2), deletion of 4 bp from the 5′-end of exon 8 (CAR SV3), insertion of 195 bp intron 7 (CAR SV4), and insertion of 91 bp intron 6 (CAR SV5). In contrast, only CAR SV5 was detected in lung. Due to the introduction of novel stop codons, all the SVs were considered to code for premature proteins. The liver homogenate gave two protein bands in the vicinity of 37 kDa on Western blotting. They were attributable to CAR WT and SV-complex, respectively, based on their putative molecular weights in descending order. Upon cotransfection with the reporter plasmid, only the cells transfected with the CAR SV4-expression plasmid showed enhanced luciferase activity similar to the WT-transfected cells, for which the further splicing of the remaining intron 7 seemed to be responsible. The transactivation-defective SVs downregulated CAR WT-induced luciferase activity to some extent in the cotransfection experiments.
In the present investigation the chemopreventive action of Panax ginseng extract, EFLA400, in Swiss albino mice has been evaluated. We used a 9-week medium term anticarcinogenicity test model of lung adenomas [Yun et al.1)]. Lung adenomas were induced by single subcutaneous injection in the subscapular region with 0.02 ml of benzo(a)pyrene (BP) (0.5 mg suspension in 1% aqueous gelatin) in newborn mice (less than 24 h old). Also chromosomal aberrations and micronuclei induction were evaluated in bone marrow cells. These genotoxicity end-points were compared with adenoma incidence at the same dose levels of BP and EFLA400. The oral administration of EFLA400 (10 mg/kg body weight) showed significant reduction in number of adenomas and weight of the lungs induced by BP. A significant reduction (p<0.001) in lung adenoma incidence in EFLA400-treated mice was observed as compared to the 68.3±2.96% lung adenoma incidence in BP-alone group. The inhibition rate was 72.05±1.36% in EFLA400-treated group with respect to the reference group (BP-alone group). However, tumor multiplicity was observed as 0.91±0.08 and 0.25±0.01 in BP alone and BP+EFLA400-treated groups respectively. In EFLA400-treated group significantly reduced frequencies of chromosomal aberrations and micronuclei induced by BP were observed. The results of the present investigation suggest the chemopreventive action and antimutagenic effect of EFLA400 in Swiss albino mice induced by BP in newborn mice.
Drug resistance has been a major limitation to chemotherapy. There are many mechanisms that contribute to such resistance. In our study, we subcloned oridonin-sensitive and low sensitive L929 cells and both types of cells grew at almost the same growth rate. The acquired low sensitivity to oridonin-induced apoptosis was associated with Bcl-2 up-regulation and down-regulation of p53 phosphorylation. The p38 inhibitor SB203580 decreased Bcl-2 expression in the low sensitive L929 cells and made the cells more sensitive to oridonin. Moreover, a higher dose of oridonin promoted p53 phosphorylation, increased Bax expression and subsequently induced death of low sensitive L929 cells, however, it had no effect on Bcl-2 expression. The increased Bcl-2/Bax ratio in oridonin low sensitive L929 cells did not inhibit caspase-9 or -3 activation, but suppressed the cleavage of poly (ADP-ribose) polymerase (PARP), indicating the existence of caspase-9 or -3 independent PARP activation. These results indicated that in L929 cells, there was a relationship among the low sensitivity to oridonin, down-regulation of p53 phosphorylation and Bcl-2 up-regulation.
We investigated the mechanism of inhibition of loxoprofen sodium, a non-steroidal anti-inflammatory drug (NSAID), and its active metabolite (loxoprofen-SRS) on cyclooxygenase (COX). In in vitro assays, loxoprofen sodium appeared inactive against recombinant human COX-1 and COX-2, whereas loxoprofen-SRS inhibited both. In the investigation of kinetic behavior, loxoprofen-SRS showed time-dependent inhibition for both isozymes. Human whole blood assay also showed that loxoprofen-SRS possesses the profile of a non-selective inhibitor for COX. In a rat air pouch model, oral administration of loxoprofen sodium lowered prostaglandin (PG) E2 in both fluid exudates of the inflammatory pouch and stomach tissue with ED50 values of 2.0 and 2.1 mg/kg, respectively. Additionally, platelet thromboxane B2 production was also inhibited by loxoprofen sodium (ED50 of 0.34 mg/kg). In a rat carrageenan-induced paw edema model, loxoprofen sodium dose-dependently reduced the paw edema, accompanied by a decrease in PGE2 content in inflamed paw exudates. These findings suggest that the COX inhibitory activity of loxoprofen sodium is attributable to its active metabolite, loxoprofen-SRS, and that loxoprofen-SRS shows non-selective inhibition for COX.
In the present study, we investigated the effects of a long-term treatment with vitamin E, an antioxidant vitamin, insulin, or their combination on renal damage in streptozotocin (STZ)-induced diabetic rats fed a high cholesterol diet. Increases in urinary albumin and lipid peroxide (LPO) excretions were observed in these diabetic rats, when both urinary parameters were measured at 8 and 15 weeks after STZ administration. Daily treatment with vitamin E, insulin, or their combination markedly suppressed the increase in the 24 h urinary albumin and lipid peroxide excretions. Furthermore, glycogen degeneration of distal tubules, fatty degeneration of glomerular endothelium and hypertrophy of glomeruli and mesangium were observed in the kidneys of the diabetic animals when histopathological evaluation was performed at 4, 8, and 15 weeks (glomerular and mesangial hypertrophy were observed only at 15 weeks). Combined vitamin E and insulin treatment was the most effective at suppressing these renal histopathological changes. These results indicate that combined vitamin E and insulin treatment additively prevents the development and progression of renal damage in diabetic rats. Possible mechanisms for the preventive effect of this combined treatment are discussed.
Serum thymic factor (FTS), a thymic peptide hormone, has been reported to increase superoxide disumutase (SOD) levels in senescence-accelerated mice. In the present study, we examined the effect of FTS on cephaloridine (CER)-induced nephrotoxicity in vivo and in vitro. We previously reported that CER led to extracellular signal-regulated protein kinase (ERK) activation in the rat kidney. So, we also investigated whether FTS has an effect on ERK activation induced by CER. Treatment of male Sprague-Dawley rats with intravenous CER (1.2 g/kg) for 24 h markedly increased BUN and plasma creatinine levels and urinary excretion of glucose and protein, decreased creatinine clearance and also led to marked pathological changes in the proximal tubules, as revealed by electron micrographs. An increase in phosphorylated ERK (pERK) was detected in the nuclear fraction prepared from the rat kidney cortex 24 h after CER injection. Pretreatment of rats with FTS (50 μg/kg, i.v.) attenuated the CER-induced renal dysfunction and pathological damage. FTS also suppressed CER-induced ERK activation in the kidney. In vitro treatment of the established cell line, LLC-PK1 cells, with FTS significantly ameliorated CER-induced cell injury, as measured by lactate dehydrogenase (LDH) leakage. Our results, taken together with our previous report that MEK inhibitors ameliorated CER-induced renal cell injury and ERK activation induced by CER, suggest that FTS participates in protection from CER-induced nephrotoxicity by suppressing ERK activation induced by CER.
We examined whether 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) improve glucose intolerance in spontaneously diabetic Goto–Kakizaki (GK) rats or not. The fasting blood glucose, plasma insulin, and serum cholesterol levels were significantly higher in GK rats than those in age-matched Wistar rats. All rats were given orally once a day 0.5% carboxymethylcellulose, pravastatin 8 mg/kg, simvastatin 8 mg/kg, or atorvastatin 8 mg/kg. An oral glucose tolerance test (OGTT) was performed before and 3, 6 and 12 weeks after statin treatments. The hyperglycemic response to OGTT in GK rats significantly exceeded that in Wistar rats. The plasma insulin level in GK rats increased with age until 14-week-old (treated for 6 weeks), and then decreased. Glucose intake significantly increased the plasma insulin in almost all rats. The increment of plasma insulin due to OGTT in GK rats appeared to be less than that in Wistar rats, because the basal level was already high in GK rats. Pravastatin, simvastatin, and atorvastatin did not modify changes in blood glucose and plasma insulin induced by glucose intake. In conclusion, long-term treatments of GK rats with statins did not improve glucose intolerance observed during OGTT.
Chemotherapy using anticancer drugs induces serious the problem of multidrug resistance (MDR) in the cancer cells. In contrast, endothelial cells so rarely acquire MDR that antiangiogenesis therapy has recently been considered as an effective means for cancer chemotherapy. We screened compounds in the chemical library to find a novel and orally active antitumor agent with vascular endothelial growth factor receptor-2 tyrosine kinase (VEGF-R2 TK) inhibition. The result was YM-231146 (IC50=0.080 μM). YM-231146 inhibited VEGF-stimulated proliferation, VEGF-R2 autophosphorylation, and vessel sprout formation of human vascular endothelial cells at concentrations between 0.15—0.30 μM. However, YM-231146 did not inhibit cancer cell proliferation at these concentrations (IC50>5 μM). In the in vivo studies, once-daily oral dosing of YM-231146 to human cancer xenografts elicited antitumor activity at doses of 3—100 mg/kg. Moreover, YM-231146 completely inhibited tumor growth of paclitaxel-resistant cancer cells without decreasing body weight at a dose of 100 mg/kg. These results suggest that YM-231146 is a novel orally bioavailable inhibitor of VEGF-R2 that would be useful for the treatment of multidrug resistant tumors.
1,3-β-D-Glucan synthase, which synthesizes a main component of fungal cell wall, is one of the promising targets for antifungal agents. In order to identify novel chemical classes of 1,3-β-D-glucan synthase inhibitors, we screened a chemical library monitoring inhibition of the Candida albicans 1,3-β-D-glucan synthase activity. The piperazine propanol derivative GSI578 [(2,6-difluoro-phenyl)-carbamic acid 3-(4-benzothiazol-2-yl-piperazine-1-yl)-propyl ester] was identified as a potent inhibitor against 1,3-β-D-glucan synthase with an IC50 value of 0.16 μM. GSI578 exhibited in vitro antifungal activity against pathogenic fungi including C. albicans and Aspergillus fumigatus. Temperature-sensitive mutations of the FKS1 gene in the Δfks2 background of Saccharomyces cerevisiae, where FKS1 and FKS2 encode putative catalytic subunits of 1,3-β-D-glucan synthase, altered sensitivity to GSI578. This suggests that the antifungal activity of the piperazine propanol derivative has an effect on 1,3-β-D-glucan synthase inhibition. Results of our initial evaluation suggest that the piperazine propanol derivative is a novel chemical structure of the class of antifungals which inhibit fungal cell growth by inhibiting fungal 1,3-β-D-glucan synthase.
The effect of the combination of β-cryptoxanthin and zinc sulfate (zinc) on bone components in the femoral-diaphyseal and -metaphyseal tissues of young rats in vitro was investigated. Bone tissues were cultured for 48 h in a serum-free Dulbecco's modified Eagle's medium containing either vehicle, β-cryptoxanthin (10−9—10−7 M) or zinc sulfate (10−6—10−4 M). The presence of β-cryptoxanthin (10−9 M) or zinc (10−6 M) did not have a significant effect on calcium content in the femoral-diaphyseal or -metaphyseal tissues. However, culture which combined β-cryptoxanthin (10−9 M) and zinc (10−6 M) caused a significant increase in calcium content in the femoral-diaphyseal and -metaphyseal tissues. Such an effect was not observed by the combination of β-cryptoxanthin (10−9 M) plus genistein (10−6 M) or menaquinone-7 (10−6 M), or zinc (10−6 M) plus genistein (10−6 M) or menaquinone-7 (10−6 M). Also, the combination of β-cryptoxanthin (10−9 M) plus zinc (10−6 M) caused a remarkable increase in alkaline phosphatase activity and deoxyribonucleic acid (DNA) in the femoral-diaphyseal and -metaphyseal tissues, while their application alone did not have an effect on the enzyme activity or DNA content in the femoral tissues. The effect of the combination of β-cryptoxanthin (10−9 M) plus zinc (10−6 M) in increasing calcium content, alkaline phosphatase activity, and DNA content in the femoral-diaphyseal and -metaphyseal tissues was completely prevented in the presence of cycloheximide (10−6 M), an inhibitor of protein synthesis, or 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DBR), an inhibitor of transcriptional activity. This study demonstrates that the combination of β-cryptoxanthin and zinc at a lower concentration has a synergistic effect on bone components in vitro.
Cetraxate hydrochloride (cetraxate), ecabet sodium (ecabet), and sulpiride, which are cytoprotective drugs, have been used to treat peptic ulcers and acute or chronic gastritis. They are reported to improve mucosal blood flow in the stomach. One of the most important factors believed to cause gastric ulcers is mental and/or physiological stress. When people feel stress, the hypothalamo-pituitary-adrenal (HPA) axis is activated. Therefore, corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and cortisol can be indicators of stress. We examined the effects of cetraxate, ecabet and sulpiride on the plasma levels of ACTH and cortisol under stress conditions by repetitive blood sampling. Venous blood samples were taken before and 20—240 min after a single administration of the drugs or a placebo. A single dose of ecabet caused significant suppression of increases in plasma ACTH-like immunoreactive substance (IS) levels at 90 to 120 min and cortisol levels at 240 min, compared with the response to placebo. Sulpiride only suppressed increases in plasma cortisol levels at 180 to 240 min, compared with the response to placebo. A single dose of cetraxate had no effect on plasma ACTH-IS and cortisol levels. Ecabet may have a modulatory effect on the HPA axis while sulpiride may have a partial modulatory effect on the HPA axis. These effects might be beneficial in stress-related disease.
To elucidate the details of tryptase release from the heart during ischemia-reperfusion (I/R), we attempted the enzymatic measurement of tryptase release from the isolated guinea pig heart perfused by the Langendorff mode I/R model. Tryptase-like activity in the effluent was monitored by the hydrolysis of L-Pyr-Gly-Arg-MCA. Tryptase-like protease and histamine were rapidly released from heart during ischemia within 10 min. After reperfusion, tryptase-like protease levels decreased, achieving stabilization. The tryptase-like protease activity in the effluent was inactivated by serine protease inhibitors. The pattern of inhibition was similar to those of guinea pig and human lung tryptase. In conclusion, tryptase was released into the coronary effluent during ischemia, but not during reperfusion in guinea pig heart.
Protopanaxadiol ginsenosides Rb2 and Rc were transformed using cell-free extracts from various edible food microorganisms and then analyzed by TLC and HPLC. Rb2 and Rc were transformed into compound K via Rd and F2 by Bifidobacterium sp. Int57 and Bifidobacterium sp. SJ32. Lactobacillus delbrueckii transformed Rb2 and Rc into ginsenoside Rh2. Bifidobacterium sp. SH5 transformed Rb2 and Rc into F2. Aspergillus niger transformed Rb2 into compound K via compound O and compound Y, whereas it transformed Rc into compound K via Mc. Taken together, these processes would allow a specific bioconversion process to obtain specific ginsenosides using an appropriate combination of ginsenoside substrates and specific microbial enzymes.
The pancreatic lipase inhibitors were isolated from the fructus of Gardenia jasminoides ELLIS, and their antihyperlipidemic activities were measured. Gardeniae fructus (GF) water extract inhibited pancreatic lipase activity. Crocetin and crocin were isolated from GF water extract as inhibitors of pancreatic lipase with an IC50 value of 2.1 and 2.6 mg/ml (triolein as a substrate). Crocin and crocetin significantly inhibited the increase of serum TG level in corn oil feeding-induced triglyceridemic mice, as well as that of serum triglyceride and total and LDL cholesterol levels in Triton WR-1339-induced hyperlipidemic mice. These compounds also showed hypolipidemic activity in hyperlipidemic mice induced by high cholesterol, high fat or high carbohydrate diets for 5 weeks. The results suggest that the hypolipidemic activity of GF and its component crocin may be due to the inhibition of pancreatic lipase and crocin, and its metabolite, crocetin, can improve hyperlipidemia.
Juzen-taiho-to (JTT) is known as a Japanese herbal medicine that increases the immune function via the enhancement of phagocytosis, cytokine induction, and antibody production. Anti-neoplastic effects on malignant gliomas have been reported by means of the enhancement of the immune function in both animals and humans. We evaluated whether JTT has anti-angiogenic effects on malignant glioma growth in vitro and in vivo. In vitro, the anti-proliferative effect of JTT on malignant glioma cells and endothelial cells was assessed by cell proliferation assay. In vivo, a subcutaneous model of malignant glioma with different-aged mice (old, 43 weeks; young, 8 weeks) was used. After oral administration of JTT to mice, their immunological function and angiogenic status of tumor tissues were assessed by flow cytometry and immunohistochemistry, respectively. JTT inhibited human endothelial cell, but not glioma cell, proliferation in vitro. In vivo, the NK (natural killer) cell ratio within PBMC (peripheral blood mononuclear cells) and NK activity of fresh splenocytes obtained from JTT-treated old mice were significantly increased compared to the ratio and activity in control mice. In old mice, the vessel area of tumor tissues in JTT treatment groups was significantly decreased. These enhancements of immunological function and the inhibition of angiogenic activity were not observed in young mice. JTT not only increased host immunological function but also exerted anti-angiogenic effects on malignant glioma growth. JTT would be useful as an adjuvant medicine for malignant gliomas through its enhancement of systemic immunological function and its anti-angiogenic action.
Nitobegiku (the herb of Tithonia diversifolia (HEMSL) A. GRAY) has been used as a medicinal plant for diabetes. The antidiabetic effect of an 80% ethanol extract of Nitobegiku (Td) was investigated in KK-Ay-mice, an animal model of type 2 diabetes. Td (500 mg/kg body weight) reduced the blood glucose of KK-Ay mice 7 h after a single oral dose. No change in blood glucose in Td-treated normal mice (ddY) was seen. Td (500 mg/kg) reduced blood glucose in KK-Ay mice 3 weeks after a single oral dose and also significantly lowered plasma insulin in KK-Ay mice under similar conditions. Td-treated KK-Ay mouse blood glucose was significantly decreased in an insulin tolerance test. These results support the hypothesis that Td improves glucose metabolism by reducing insulin resistance. Therefore, Nitobegiku may be useful for the treatment of type 2 diabetes.
The bioassay-guided fractionation of the MeOH extract of Galla Rhois furnished two hepatoprotective compounds, an equilibrium mixture of 3-galloyl-gallic acid and 4-galloyl-gallic acid isomers (3), 1,2,3,4,6-penta-O-galloyl-β-D-glucose (4), and two inactive phenolic compounds, gallic acid methyl ester (1) and gallic acid (2). Compounds 3 and 4 showed significant hepatoprotective effects with EC50 values of 70.39±5.4 and 29.51±0.7 μM, respectively, against tacrine-induced cytotoxicity, and 150.9±6.4 and 23.81±0.5 μM, respectively, against nitrofurantoin-induced cytotoxicity in Hep G2 cells.
Four anthraquinones isolated for the first time from the aerial parts of Rumex acetosa (Polygonaceae), a Korean and a Japanese medicinal plant, and two synthetic derivatives were examined for their cytotoxicities against five cultured human tumor cell lines, i.e. A549 (non-small cell lung), SK-OV-3 (ovary), SK-MEL-2 (melanoma), XF498 (central nerve system) and HCY15 (colon), using the Sulfrhodamine-B method in vitro and antimutagenic activities by Ames test with Salmonella typhimurium TA98 and TA100 and SOS chromotest with E. coli PQ37. Among the tested compounds, emodin strongly inhibited the proliferation of each examined tumor cell line with IC50 values ranged from 2.94 to 3.64 μg/ml and showed potent antimutagenic activities with 71.5% and 53.3% at the concentration of 0.1 mg/plate against the mutagens, NPD and sodium azide, respectively. Its antigenotoxic activity was also very effective at the final concentration of 10 μg/reaction tube against the mutagens, MNNG and NQO by SOS chromotest, reducing the induction factors by 19.6% and 43.5%, respectively. The structure–activity correlation study suggests that an additional OH group at C-6 position in the anthraquinone nucleus may play an important role for their cytotoxicities and an introduction of OH– or OCH3 group at C-6 position is necessary for their antimutagenicities.
Bofutsushosan (BOF), a traditional Chinese formulation (Kampo formulation in Japanese), is widely used for patients with obesity and hyperlipidemia resulting from long-term inappropriate lifestyles. Since atherosclerosis, a lifestyle-related disease, is accompanied by an abnormal accumulation of vascular smooth muscle cells (VSMCs) in the intimal area of the artery, we investigated the preventive effect of BOF on intimal thickening. Oral administration of BOF extracts 3 d before and 7 d after balloon endothelial denudation dose dependently suppressed the intimal thickening and proliferation of VSMCs in the intimal area in rat carotid arteries. This model has a similar pathologic process to atherosclerosis and is considered to be an “accelerated atherosclerosis” model. BOF extract also dose dependently inhibited the migration of cultured VSMCs. BOF extract suppressed serum lipid levels, which are a major risk factor for atherosclerosis. These findings clarified the usefulness of BOF in cardiovascular risk-reduction therapy.
We investigated the genotypic status of thiopurine methyltransferase (TPMT) polymorphism to evaluate the possible risk of the toxicity of azathioprine (AZA) in 68 patients with systemic lupus erythematosus (SLE). The allele frequency of TPMT mutation in the SLE group (2.9%) was higher than that in 174 Japanese healthy volunteers (1.1%), although it did not reach statistically significant difference (p=0.23). The mean value of TPMT activities in 51 subjects with TPMT*1/*1 was 40% higher than that of 4 subjects with TPMT*1/*3C in SLE group (18.1±6.1 nmol/h/ml packed red blood cells (pRBC) versus 13.2±3.2 nmol/h/ml pRBC; p=0.11). Two out of 4 SLE patients with TPMT*1/*3C had been treated with AZA, and one patient showed a leucopenia. The TPMT genotyping before AZA treatment is recommended for Japanese SLE patient group to avoid the AZA-induced adverse events, although detection of the patient with low TPMT activity by genotyping is still imperfect.
The 5-hydroxytryptamine3A (5-HT3) receptor is closely related with irritable bowel syndrome (IBS) in enteric nervous systems. We previously demonstrated that ginseng total saponins (GTS, also called ginsenosides), the active ingredients of Panax ginseng, inhibit the activity of 5-HT3A receptor channels expressed in Xenopus laevis oocytes. Here, we further investigated whether the in vitro inhibitory effect of ginsenosides on 5-HT3A receptor channel activity is coupled to in vivo attenuation of IBS. A rat model of IBS was induced by colorectal distention (CRD) and intracolonic infusion of 0.6% acetic acid (CRD-acetic acid), and visceral hypersensitivity was assessed by counting the contractions in the external oblique muscles of conscious rats during the 10 min distention period. We found that oral administration of GTS significantly and dose-dependently inhibited CRD-acetic acid-induced visceral hypersensitivity. The EC50 was 5.5±4.7 mg/kg (95% confidence intervals: 1.2—15.7) and the inhibitory effect of GTS against visceral hypersensitivity persisted for 4 h. When we compared the effects of protopanaxadiol (PD) ginsenosides and protopanaxatriol (PT) ginsenosides against CRD-acetic acid-induced visceral hypersensitivity, we found that PT but not PD ginsenosides significantly attenuated the CRD-acetic acid-induced visceral hypersensitivity. These results indicate that PT ginsenosides of Panax ginseng might be the main active components for the attenuation of experimentally CRD-acetic acid-induced visceral hypersensitivity, and may be clinically relevant for the future treatment of IBS.
We investigated the effect of plasmid DNA (pDNA) solution composition on gene transfection following liver surface administration in mice. Gene transfection experiments in situ and in vivo were performed using the following pDNA solutions: dextrose solution, NaCl solution, phosphate buffer, phosphate-buffered saline, Tris/HCl buffer with EDTA, Tris/HCl buffer with EDTA and Triton X-100, and water. In in situ experiments, we used a glass cylindrical diffusion cell that limited the contact area between the liver surface and the naked pDNA solution. The gene transfection at the site of diffusion cell attachment increased in hypotonic solution, and decreased in hypertonic solution, compared with isotonic solution. In in vivo experiments, instillation of naked pDNA solution onto the liver surface using a micropipette caused no significant differences in gene transfection in the applied lobe. These results suggest that it is important to select the optimal pDNA solution composition to control the gene transfection.
The pharmacokinetics of panipenem in experimental renal failure animal models was investigated in order to identify the appropriate covariates affecting the pharmacokinetic behavior. Panipenem and betamipron were administered intravenously to rats with a variety of renal failures, such as nephritis induced by glycerol, gentamicin, uranium and antiserum against glomerular basement membrane as well as 5/6 subtotal nephrectomy. Panipenem in plasma and urine was determined and pharmacokinetic analysis was performed using a one-compartment open model. The elimination half-life prolonged and total body clearance, renal clearance (CLR) and renal excretion ratio were decreased according to the renal function, i.e. control>glycerol>anti-GBM=gentamicin>nephrectomy=uranium in order. However, distribution volume was consistent in all models. CLR showed strong positive correlation with the glomerular filtration rate in spite of a weak correlation with the reciprocal of blood urea nitrogen. However, no obvious correlation was observed with secretory clearance of N-1-methylnicotinamide. This preliminary information based on animal model might be useful for designing pharmacokinetic studies in special population at early stage of new drug development.
The methanolic extract of leaves of Camellia sinensis (L) O. KUNTZE was screened for antimicrobial property against 111 bacteria comprising 2 genera of Gram positive and 7 genera of Gram negative bacteria. Most of these strains were inhibited by the compound at 10—50 μg/ml level and few strains were sensitive even at lower concentrations (5 μg/ml). The bacteria could be arranged in the decreasing order of sensitivity towards the compound in the following manner: Staphylococcus aureus, Vibrio cholerae, Escherichia coli, Shigella spp., Salmonella spp., Bacillus spp., Klebsiella spp. and Pseudomonas aeruginosa. The antibacterial activity of compound could also be confirmed in vivo. When it was given to Swiss strain of white mice at different dosages (30, 60 μg/mouse), it could significantly protect the animals challenged with 50 MLD of Salmonella typhimurium NCTC 74. According to Chi square test the in vivo data were highly significant (p<0.001).
Dilated cardiomyopathy (DCM) is a major cause of morbidity and mortality. Occurrence of myocardial fibrosis is an important event in the ventricular remodeling process, which takes place during DCM. Mast cells are well known inflammatory cells implicated in various biological phenomena. The involvement of mast cells in the development of myocardial fibrosis of DCM in rats after autoimmune myocarditis remains unknown. Nine-week-old male Lewis rats were immunized with cardiac myosin and divided into vehicle treated (group V) and disodium cromoglycate (DSCG), a mast cell stabilizer (24 mg/kg i.p.) treated (group DSCG) groups. The animals were sacrificed after 60 d of immunization. The myocardium was excised and preserved for histopathology and protein analysis. Myocardial levels of transforming growth factor (TGF) β1 and collagen-III were quantified. Staining of mast cells was performed by toluidine blue. A significant correlation was obtained between myocardial fibrosis and cardiac mast cell density. DSCG reduced myocardial fibrosis besides preventing infiltration and degranulation of mast cells. Our findings confirm the active participation of mast cells in the progression of myocardial fibrosis in rats with postmyocarditis DCM.
Here we report a primary structure conserved between Helicobacter pylori (H. pylori)-tumor necrosis factor-α inducing protein (Tipα) and bacterial penicillin-binding proteins. H. pylori is a Gram-negative bacterium which plays a key part in carcinogenesis in the human stomach. We previously reported that Tipα has a carcinogenic potential as tumor promoter, and that it has no obvious homologue in other species. To investigate the structure–function relationship of Tipα and to predict its ancestral protein, we searched among proteins which have weak homology to Tipα in their primary structures, using Psi-Blast, and we identified numerous Gram-positive bacterial penicillin-binding proteins as weakly homologous to Tipα. Among these, several unique amino acids are conserved and form a motif-like structure. Phylogenic tree analysis indicated that Tipα is closer to the penicillin-binding proteins of Gram-positive bacteria, based on their primary structures, than to H. pylori. This finding suggests that Tipα and penicillin-binding proteins are derived from a common ancestral protein, and that Tipα gene may be transferred horizontally from Gram-positive bacteria to H. pylori.
Long term and repeated exposure of UV light on the skin often induces chronic skin diseases such as skin cancer as well as photoaging, and the mechanisms of these skin damages are closely associated with up-regulation of matrix metalloproteinase's (MMPs) activities. We investigated the effect of 2′,4′,7-trihydroxyisoflavone purified from the whole plants of Viola hondoensis W. BECKER et H BOISSIEU (Violaceae) on the expression of MMPs in UV-B irradiated old aged human skin fibroblasts. 2′,4′,7-trihydroxyisoflavone markedly reduced UV-induced MMP-1 expression, but not MMP-2, at the both mRNA and protein levels in a dose-dependent manner. Our report is the first description for the ability of 2′,4′,7-trihydroxyisoflavone to regulate MMP-1 expression from ultraviolet-B irradiated primary cultured old aged human skin fibroblasts.
Ethanol and aqueous extracts of Machilus thunbergii used traditionally for the treatments a wide variety of diseases were screened in vitro for the matrix metalloproteinase (MMP)-9 inhibitor actions. Meso-dihydroguaiaretic acid from the stems bark of Machilus thunbergii showed significant MMP-9 inhibition in human keratinocyte cells cause by ultraviolet irradiation. Here we investigated the effect of meso-dihydroguaiaretic acid, which was isolated from Machilus thunbergii, on UV-induced premature skin aging. We studied the effect of meso-dihydroguaiaretic acid on UV-induced MMP-9 expression in an immortalized human keratinocyte cell line, HaCaT, in vitro. Acute UV irradiation induced MMP-9 expression at both the mRNA and protein levels and meso-dihydroguaiaretic acid suppressed this UV-induced MMP-9 expression in a dose-dependent manner. Taken together, these results show that meso-dihydroguaiaretic acid can prevent the harmful effects of UV that lead to skin aging. Therefore, we suggest that meso-dihydroguaiaretic acid should be viewed as a potential therapeutic agent for preventing and/or treating premature skin aging.