Rhodiola crenulata root ameliorates derangements of glucose and lipid metabolism in a rat model of the metabolic syndrome and type 2 diabetes

Ethnopharmacological relevance

Rhodiola species are traditionally used as tonics and stimulants to treat asthenia, suggesting their possible regulatory effect on energy metabolism. Clinical trials have demonstrated their glucose-lowering effect in type 2 diabetes.

Aim of the study

To examine the effects of Rhodiola on glucose and lipid metabolism in the metabolic syndrome and type 2 diabetes.

Materials and methods

Zucker diabetic fatty (ZDF) rats were treated with Rhodiola crenulata root (RCR) powder (100 and 500 mg/kg, by gavage, once daily for 4 weeks). In addition, the effects of RCR on sucrose-induced acute hyperglycemia in mice and olive oil-induced hypertriglyceridemia in rats were also examined. Biochemical variables were determined enzymatically or by ELISA.

Results

In ZDF rats, RCR treatment decreased the increased plasma insulin and triglyceride concentrations at baseline, the index of the homeostasis model assessment of insulin resistance (HOMA-IR) and excessive hepatic triglyceride accumulation. This treatment also inhibited abnormal increases in plasma glucose and insulin concentrations during oral glucose tolerance test. Furthermore, RCR reversed the increased adipose insulin resistance index, and accelerated the decline of plasma concentrations of non-esterified fatty acids after exogenous glucose stimulation. However, RCR minimally affected sucrose-induced acute hyperglycemia in mice and olive oil-induced acute hypertriglyceridemia in rats.

Conclusions

The present results demonstrate that RCR treatment improves metabolic derangements in animal model of the metabolic syndrome and type 2 diabetes. Our findings may provide new pharmacological basis of therapeutics for the adaptogenic plants to treat metabolic derangements-associated disorders, such as asthenia.     

Modulation of hepatic sterol regulatory element-binding protein-1c-mediated gene expression contributes to Salacia oblonga root-elicited improvement of fructose-induced fatty liver in rats

Ethnopharmacological relevance

Salacia oblonga root (SOR) is a traditionally herbal medicine for obesity and diabetes, which are closely associated with fatty liver. To investigate the molecular mechanisms of SOR in the treatment of dietary-induced fatty liver.

Materials and methods

Male rats were co-administered with fructose in drinking water and vehicle or the aqueous-ethanolic extract of SOR (by gavage, once daily) for 10 weeks. Biochemical variables were determined enzymatically or by ELISA. Gene expression was analyzed by Real-Time PCR and/or Western blot.

Results

SOR treatment (20 mg/kg) diminished fructose-induced fatty liver indicated by decreases in excess triglyceride accumulation and the increased vacuolization and Oil Red O staining area in the livers of rats. Importantly, Hepatic gene expression profile revealed that SOR suppressed fructose-stimulated overexpression of sterol regulatory element-binding protein (SREBP)-1/1c mRNA and nuclear protein. In accord, overexpression of SREBP-1c-responsive genes, such as fatty acid synthase, acetyl-CoA carboxylase-1 and stearoyl-CoA desaturase-1, was also downregulated. In contrast, overexpressed nuclear protein of carbohydrate response element binding protein and mRNA of its target gene liver pyruvate kinase were not altered. Additionally, SOR also did not affect expression of peroxisome proliferator-activated receptor-gamma- and -alpha, as well as their target genes, such as carnitine palmitoyltransferase-1a, acyl-CoA oxidase and CD36.

Conclusions

These results suggest that modulation of hepatic sterol regulatory element-binding protein-1c-mediated gene expression contributes to SOR-elicited improvement of fructose-induced fatty liver in rats. Our findings provide a better understanding of SOR in the treatment of obesity and diabetes.     

Protective effects of astragaloside IV on porcine-serum-induced hepatic fibrosis in rats and in vitro effects on hepatic stellate cells

Ethnopharmacological relevance

Astragaloside IV is the primary pure saponin isolated from Astragalus membranaceus, one of the valuable traditional medical herbs. Antifibrotic activities of Astragalus membranaceus have been extensively proved.

Aim of the study

To investigate the effects of astragaloside IV on hepatic stellate cells (HSCs) and hepatic fibrosis in rats induced by porcine-serum (PS).

Materials and methods

Liver fibrosis was induced by PS injection (0.5 ml, twice a week) for 12 weeks. Astragaloside IV (2.0, 4.0 mg kg⁻¹) was administered intragastrically. Liver samples were subjected to histological and immunohistochemical studies. In vitro effects of astragaloside IV on primary cultured HSCs were detected by incorporation assays.

Results

Astragaloside IV delayed the formation of liver fibrosis and decrease the serum levels of hyaluronic acid (HA), procollagen type III (PCIII) and hydroxyproline (Hyp) content in liver. The levels of transforming growth factor-β₁ (TGF-β₁) in serum and expression in liver were significantly decreased by astragaloside IV. Collagen synthesis and proliferation were significantly inhibited by astragaloside IV (1.5, 3.0, 6.0, 12.0 and 24.0 mg L⁻¹) in HSCs.

Conclusion

The results showed that astragaloside IV displays antifibrotic effects in rats induced by PS, the mechanism by which might be associated with its inhibitory effects on collagen synthesis and proliferation in HSCs.     

Study on effects of zhi zi (fructus gardeniae) on non-alcoholic fatty liver disease in the rat

Objective

To investigate the effects of Zhi Zi (Fructus Gardeniae) on non-alcoholic fatty liver disease (NAFLD) induced by a high-fat diet in the rat.

Methods

A rat model of NAFLD was established using a high-fat diet. Twenty one rats were randomly divided into a normal group, a model group and a Zhi Zi treatment group, 7 rats per group. Drinking water and the drug were intragastrically administrated for 5 weeks. Samples were then taken to observe pathological changes of the liver tissue (HE staining); changes in the fat metabolism pathway e. g. triglyceride (TG) and free fatty acid (FFA) content; alterations in liver function, i.e. serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity; and differences in tumor necrosis factor α (TNF-α) and P-lkB protein expression in the liver tissue.

Results

Fatty degeneration and vacuole-like changes of different degrees occurred in hepatic cells of the model group. Markers for fat metabolism, serum ALT and AST activities, and expression of TNF-α and P-lkB proteins in liver tissue significantly increased. Fat metabolism in the Zhi Zi group significantly reduced, as shown by a drop in marker levels. Serum ALT and AST activities, and expression of TNF-α, P-lkB proteins in liver tissue were also significantly decreased in this group.

Conclusion

Zhi Zi has a very strong inhibitory action on lipidosis and inflammatory injury in the rat model of NAFLD. This mechanism may possibly be related to the inhibition of the free fatty acid metabolism pathway.     

Inhibitory effects of salvianolic acid B on CCl4-induced hepatic fibrosis through regulating NF-κB/IκBα signaling

Ethnopharmacological relevance

Hepatic fibrosis, a precursor of liver cirrhosis, is a consequence of severe liver damage that occurs in many patients with chronic liver diseases. Salvianolic acid B (SA-B) is one of water soluble compounds derived from Salvia miltiorrhiza Bunge (Danshen in Chinese) widely used for chronic liver diseases. In this study we investigated the protective effects of SA-B on CCl₄-induced hepatic fibrosis.

Materials and methods

Hepatic fibrosis in rats was induced by carbon tetrachloride (CCl₄). Rats were divided into four groups, including normal controls (N group), model (M group), low SA-B of 10 mg/kg body weight (L group), or high SA-B of 20 mg/kg body weight (H group). After 6 weeks, macroscopic features of the liver and weight ratio of liver to body were measured. Liver fibrosis of the rats was evaluated by HE and Massion staining. Activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBIL) were checked with automated biochemistry analyzer. Serum levels of hyaluronic acid (HA), type IV collagen (IV-C), Laminin (LN) and procollagen III peptide (PIIIP) were detected by radioimmunoassay (RIA). The expression of NF-κB and IκBα was detected by western blotting.

Results

SA-B was shown to reduce CCl₄-induced hepatic fibrosis in rats. The serum levels of ALT, AST, and TBIL were significantly lower in the SA-B treatment groups than in the M group. Compared the M group, the serum levels of HA, LN, IV-C and PIIIP were decreased markedly after treatment with SA-B, especially in the H group. Treatment with SA-B at 10–20 mg/kg (L and N groups, respectively) dose-dependently decreased the expression of NF-κB in the nucleolus and increased the expression levels of NF-κB and IκBα protein in the cytoplasm compared to that of the M group.

Conclusions

This study reveals that SA-B could prevent the progression of liver angiogenesis and alleviate liver fibrosis possibly by regulating the expression of NF-κB and IκBα.     

Polyprenols from Taxus chinensis var. mairei prevent the development of CCl4-induced liver fibrosis in rats

Ethnopharmacological relevance

The aim of this study was to investigate the anti-fibrotic effects and the possible underlying mechanisms of taxus polyprenols (TPs) isolated from the needles of Taxus chinensis var. mairei.

Materials and methods

The animals were randomly divided into normal control with vehicles only (olive oil), rat model given CCl₄ only, CCl₄+low TPs (48 mg/kg), CCl₄+medium TPs (120 mg/kg), CCl₄+high TPs (300 mg/kg), and CCl₄+Polyene phosphatidylcholine (PP, 120 mg/kg). The rat model of liver fibrosis was induced by subcutaneous injection of 40% (v/v) of CCl₄ diluted in olive oil (3 mL/kg body weight) twice per week for 8 weeks. Liver histopathological study was performed. Aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and albumin (ALB) of the serum were determined for evaluating the liver function. In order to reveal the possible mechanisms of the anti-fibrotic effects, oxidative stress level, hepatic collagen metabolism, and hepatic stellate cells (HSCs) activation were investigated. Furthermore, the mRNA expression of the fibrotic-related factors was measured by the quantitative real-time RT-PCR.

Results

TPs successfully attenuated liver injury induced by CCl₄ shown by histopathological sections of livers and improved liver function as indicated by decreased ALT, AST and ALP levels and increased ALB levels in serum of the rats. TPs significantly increased the hepatic Cu/Zn SOD and GSH-Px activities along with GSH content while a remarkable decrease in MDA content. Both immunohistochemical staining and mRNA expression levels of α-SMA indicated a profound suppression of HSCs activation. Furthermore, it significantly inhibited the mRNA expression of the pro-fibrotic cytokines Col α1(I), Col α1(Ш), MMP-2, TIMP-1, TIMP-2, PDGF-β, TGF-β1, CTGF and TNF-α and restored the hepatoprotective factor HGF.

Conclusion

These results suggest that the protective effects of TPs in chronic CCl₄-induced liver fibrosis might be related with the reduction of oxidative damage, the inhibition of HSCs activation, the down-regulation of pro-fibrogenic stimuli and the protection of hepatocytes.     

Momordica charantia extract on insulin resistance and the skeletal muscle GLUT4 protein in fructose-fed rats

Aim of the study

We investigated the preventive effect of Momordica charantia Linn. (Cucurbitaceae) fruit, commonly known as bitter melon, on hyperglycemia and insulin resistance in rats fed with a fructose-enriched diet.

Materials and methods

First, rats were divided randomly into two groups: the control group was fed with control diet, whereas the experimental group was fed with a 60% high-fructose diet for 8 weeks. After the first 6 weeks, the fructose-treated rats were further subdivided into six groups and were orally fed with or without Momordica charantia L. or rosiglitazone (ROS) for 2 weeks while rats were still on fructose diet.

Results

We demonstrated that bitter melon was effective in ameliorating the fructose diet-induced hyperglycemia, hyperleptinemia, hyperinsulinemia, and hypertriglyceridemia as well as in decreasing the levels of free fatty acid (FFA) (P < 0.001, P < 0.05, P < 0.05, P < 0.05, P < 0.05, respectively). Bitter melon reversed fructose diet-induced hypoadiponectinemia (P < 0.05), which provides a therapeutic advantage to insulin resistance in improving insulin sensitivity. Additionally, bitter melon decreased the weights of epididymal (P < 0.05) and retroperitoneal white adipose tissue (WAT) (P < 0.05). Bitter melon increased the expression of peroxisome proliferator-activated receptor γ (PPARγ) in white adipose tissue (WAT). Conversely, bitter melon decreased the expression of leptin in WAT. Furthermore, we demonstrate that bitter melon significantly increases the mRNA expression and protein of glucose transporter 4 (GLUT4) in skeletal muscle.

Conclusions

This study demonstrates, for the first time, the beneficial effects of two different extracts of bitter melon on insulin resistance in rats fed a high-fructose diet thereby producing evidence of the role of changes in expression of PPARγ and GLUT4.     

Gene expression profiling and pathway network analysis of hepatic metabolic enzymes targeted by baicalein

Ethnopharmacological relevance

Baicalein is a flavone originally isolated from the roots of traditional Chinese medicinal herb, Scutellaria baicalensis, which has been proved as a promising chemopreventive compound for many chronic human diseases.

Aim of the study

The present study aimed to clarify the molecular mechanism targeted by baicalein.

Materials and methods

Gene expression profiling of HepG2 cells treated with baicalein was carried out, using the Affymetrix 42K oligonucleotide microarray in the present study. Microarray data analyzed by Ingenuity Pathway Analysis (IPA), further study performed by real time PCR, reporter gene assay, and Western blot.

Results

Among total 42K gene probes, baicalein treatment up-regulated the signals of 440 gene probes (1.04% of total gene probes) and down-regulated signals of 254 gene probes (0.6% of total gene probes) by ≥2-fold. These genes were categorized into 35 groups and hit for biological processes, molecular functions, and signaling pathways. The network and pathway analyses of these data further revealed that an Nrf2 (nuclear factor-erythroid 2 p45-related factor 2)-mediated ARE (antioxidant response element) pathway is involved in baicalein-induced gene expression of hepatic metabolic enzymes. The representative enzymes involved in Nrf2/ARE pathway were further confirmed at mRNA level by real time PCR and at protein level by Western blot analysis. Moreover, the ARE-reporter gene assay demonstrated that baicalein stimulated Nrf2-mediated ARE transactivation.

Conclusions

Our results provide a comprehensive data for understanding the hepatic metabolism, bioactive role and the molecular mechanisms of baicalein.     

Protective effect of Smilax glabra extract against lead-induced oxidative stress in rats

Ethnopharmacological relevance

Smilax glabra Roxb. is a traditional Chinese herb, the rhizome of Smilax glabra has been used in folk medicine for the treatment of lead poisoning.

Aims of the study

The present study was conducted to investigate the protective role of Smilax glabra extract (SGE) individually or combined with meso-2,3-dimercaptosuccinic acid (DMSA) against the effects of lead acetate on oxidative stress and lead burden in rats.

Materials and methods

The biochemical parameters and enzymes in different treated rats were determined by commercial kits. The metal concentrations were measured using atomic absorption spectrophotometer.

Results

SGE (300 mg/kg) showed very low toxicity to organs in non-lead exposed rats. Administration of SGE individually had no effect on blood zinc protoporphyrin (ZPP) level but significantly enhanced the glutathione (GSH) content and δ-aminolevulinic acid dehydratase (ALAD), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities in lead exposed rats. The co-treatment of SGE and DMSA had a synergism in increasing brain, liver and kidney superoxide dismutase (SOD), catalase (CAT) activities and GSH level, and decreasing oxidized glutathione (GSSG) and thiobarbituric acid reactive substances (TBARS) levels. Moreover, the co-treatment could improve the hepatic and renal histopathology changes. SGE as chelating agent showed significant efficiency in reducing blood and tissue lead burden.

Conclusions

The in vivo results suggested that SGE individually or combined with DMSA exhibited remarkable protective effects on lead-induced oxidative stress and lead burden in rats.     

Aqueous extract of Artemisia capillaris exerts hepatoprotective action in alcohol–pyrazole-fed rat model

Ethnopharmacologic relevance

Artemisia capillaris, also called “InJin” in Korean, has been widely used to treat various hepatic disorders in traditional Oriental medicine.

Aims

The purpose of this study is to evaluate the hepatoprotective effect of Artemisia capillaris (aqueous extract, WAC) on alcoholic liver injury.

Materials and methods

Liver injury was induced by oral administration of 30% alcohol (10 mL/kg, twice per day) plus pyrazole (PRZ, 30 mg/kg) with/without WAC (50, 100 mg/kg, orally once per day) or silymarin (50 mg/kg) for 10 days. The hepatoprotective effects were assessed by observing histopathological changes, hepatic transaminase enzymes, hepatic oxidation and antioxidant parameters, inflammatory cytokines, and alcohol metabolic enzymes in serum and hepatic gene expression level, respectively.

Results

Alcohol–PRZ treatment drastically increased the serum levels of aspartate transaminase (AST), alanine transaminase (ALT), and malondialdehyde (MDA) levels in serum and liver tissues while these changes were significantly ameliorated by WAC administration (p<0.05 or 0.01). The prominent microvesicular steatosis and mild necrosis in hepatic histopathology were induced by alcohol–PRZ treatment, but notably attenuated by WAC administration. Moreover, the alcohol–PRZ treatment-induced depletions of the antioxidant components including glutathione content, total antioxidant capacity (TAC), activities of glutathione peroxidase (GSH-Px), reductase (GSH-Rd), catalase, and superoxide dismutase (SOD) were significantly ameliorated by WAC administration (p<0.05, except GSH-Rd). These results were in accordance with the modulation of NF-E2-related factor (Nrf2) and heme oxygenase-1 (HO-1) gene expression. Alcohol–PRZ treatment increased the levels of tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta (TGF-β) in hepatic tissues. However they were significantly normalized by WAC administration (p<0.05 or 0.01). In addition, WAC administration significantly attenuated the alterations of aldehyde dehydrogenase (ALDH) level in serum and hepatic gene expressions of ALDH and alcohol dehydrogenase (ADH).

Conclusions

These results support the relevance in clinical use of Artemisia capillaris for alcohol-associated hepatic disorders. The underlying mechanisms may involve both enhancement of antioxidant activities and modulation of proinflammatory cytokines.     

Antidiabetic effect of flavonoids from Malus toringoides (Rehd.) Hughes leaves in diabetic mice and rats

Ethnopharmacological relevance

The leaf of Malus toringoides (Rehd.) Hughes is a traditional folk medicine in Tibet, China, which is called “E Se” in Tibetan language. This original plant grows on snow mountains at an attitude of 3000 to 3700 m. It is primarily used to treat hypertension, hyperlipidemia, hyperglycemia, indigestion and other diseases. This study aimed to evaluate the antidiabetic effect of flavonoids extracted from E Se (ESF) and to explore the potential mechanism in streptozotocin (STZ) or alloxan (ALX) induced diabetic mice and STZ-induced diabetic rats.

Materials and methods

72 h after the establishment of a diabetic model, STZ or ALX induced diabetic mice and STZ-induced diabetic rats were treated daily with ESF at doses of 45, 90, 180 mg/kg and 37.5, 75, 150 mg/kg, respectively. Both mice and rats were fasted for 5 h before administration and the blood glucose (BG) levels were tested 1 h after treatment. Body weight was determined every other day. For STZ-induced rats, glycosylated hemoglobin (Hb1Ac), serum insulin and c-peptide, hepatic glycogen, superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels in liver were assessed on the fourth day after BG level detection.

Results

Compared with the model group, the general behavior of mice treated with ESF (90, 180 mg/kg) and rats treated with ESF (75, 150 mg/kg) became better and BG levels were significantly reduced (P<0.05). Significant decrease (P<0.05) in Hb1Ac level was observed in ESF-treated rats compared with diabetic rats. Significant increase (P<0.05 ) in serum insulin and c-peptide were detected in ESF-treated rats. The treatment also significantly (P<0.05) elevated SOD activity and reduced MDA level in the liver of diabetic rats. Besides, ESF 150 mg/kg had a trend of rising hepatic glycogen content of diabetic rats.

Conclusions

The findings of this study suggest that flavonoids from the Malus toringoides (Rehd.) Hughes leaves may possess an antidiabetic activity in animals with established diabetes.     

Hepatoprotective potential of Tecomella undulata stem bark is partially due to the presence of betulinic acid

Ethnopharmacological relevance

Tecomella undulata (TU;` Family Bignoniaceae) is used in Indian Ayurvedic system of medicine for treating various diseases including hepatic ailments. It is also incorporated in various marketed hepatoprotective polyherbal formulations.

Aim

The present study was aimed at evaluating possible hepatoprotective role of isolated compounds from TU stem bark (TSB) using in vitro and in vivo experimental models.

Methods

In vitro cytotoxicity and hepatoprotective potential of various extract, fractions and isolated compounds from TU stem bark were evaluated using HepG2 cells. Rats were pre-treated with TU methanolic extract (TSB-7) or betulinic acid (MS-2) or silymarin for 7 days followed by a single dose of CCl₄ (0.5 ml/kg, i.p.). Plasma markers of hepatic damage, hepatic antioxidants and indices of lipid peroxidation along with microscopic evaluation of liver were assessed in control and treatment groups.

Results

TSB-2 and MS-1 accounted for significant cell death whereas; TSB-1, TBS-7, TSB-9, TSB-10 and, MS-2 did not register significant cytotoxicity. Further, non-cytotoxic components exhibited ascending grade of hepatoprotection in vitro (TSB-10<TSB-1<TSB-7<TSB-9<MS-2). Pre-treatment of TSB-7 or MS-2 to CCl₄ treated rats prevented hepatocyte damage as evidenced by biochemical and histopathological observations.

Conclusion

It can be concluded that, hepatoprotective potential of Tecomella undulata stem bark is partially due to the presence of betulinic acid.     

Evaluation of hepatotoxicity and cholestasis in rats treated with EtOH extract of Fructus Psoraleae

Ethnopharmacological relevance

Fructus Psoraleae (FP) has been widely used to heal skin diseases as well as osteoporosis, osteomalacia, and bone fracture. There also exist many clinical reports about FP-induced hepatotoxicity associated with acute cholestatic hepatic injury. However, the FP-induced hepatotoxicity and the underlying mechanisms remain unclear.

Aims of the study

The present study aims to determine the hepatotoxicity of FP in Sprague-Dawley (SD) rats and to investigate the underlying mechanisms.

Materials and methods

Sprague-Dawley rats of both sexes were intragastrically administered with the EtOH extract of FP (EEFP) at doses of 1.875, 1.25 and 0.625 g/kg for 28 day. Body weight, relative liver weight, biochemical analysis, histopathology, the mRNA and protein expression of Cholesterol 7α-hydroxylase (CYP7A1), farnesoid X receptor (FXR), bile-salt export pump (BSEP), multidrug resistance-associated protein 2 (MRP2), multidrug resistance-associated protein 3 (MRP3) were evaluated to study the EEFP-induced hepatotoxicity and its underlying mechanisms.

Results

Many abnormalities were observed in the EEFP-treated groups including suppression of weight gain and food intake, change of some parameters in serum biochemistry, increased weight of liver, and decreased concentration of bile acid in bile. The mRNA and protein expression of CYP7A1, MRP3, MRP2, BSEP increased and the expression of FXR decreased in EEFP-treated female groups; the mRNA and protein of FXR and CYP7A1 decreased and that of the others remained the same in EEFP-treated male groups.

Conclusion

In conclusion, we provide evidence for the first time that EEFP can induce sex-related cholestatic hepatotoxicity, and that female rats are more sensitive to EEFP-induced hepatotoxicity, which involves the destruction of the biosynthesis and transportation of bile acid. Further investigation is still needed to uncover the mechanism of the sex-dimorphic EEFP-induced hepatotoxicity.     

Effects of Bu-Zhong-Yi-Qi-Tang on hepatic drug-metabolizing enzymes and plasma tolbutamide concentration in rats

Ethnopharmacological relevance

Bu-Zhong-Yi-Qi-Tang (BT) is the dry powder derived from the aqueous extract of a mixture of 10 medicinal herbs. It is a traditional Chinese medicine being used for the treatment of various immune-related diseases.

Aim of the study

To investigate the effect of BT on hepatic drug-metabolizing enzymes and its effect on plasma concentrations of tolbutamide, a substrate of CYP2C, in rats.

Materials and methods: Exp 1

Thirty-two male Wistar rats were divided into four groups. Rats were fed a control diet and a control diet containing 1, 2.5 and 5% (w/w) of BT, respectively, for eight weeks. The activities of the major CYP and Phase II conjugating enzymes in rat liver microsomes as well as the antioxidant system in rat liver were assessed. Exp 2: Male Wistar rats were fed a control diet or a control diet containing 2.5% of BT, respectively, for eight weeks. A single 20-mg/kg oral dose of tolbutamide was then administered to each rat. Plasma samples were collected from each rat at 0.5, 1, 2, 4 and 8 h after dosing. The concentrations of tolbutamide and glucose level in plasma were determined by high-performance liquid chromatography-mass spectrometer (HPLC/MS) and enzymatic method, respectively.

Results

Significant decrease in microsomal CYP2C-catalyzed diclofenac 4-hydroxylation in the liver of rats fed the BT diet was observed. Increased UDP-glucuronosyltransferase (UGT) and glutathione S-transferase (GST) activities were also observed in the liver of rats fed the diet containing 2.5 and 5% of BT. Immunoblot analyses also showed decreases of CYP2C11 proteins in the liver of BT fed rats. In addition, rats fed the 2.5% BT diet for eight weeks had no effects on the disposition of tolbutamide and reduction of glucose level in plasma after orally administered of tolbutamide.

Conclusions

Rats fed the BT diet for eight weeks may decrease CYP2C enzyme activity and protein expression and increase Phase II conjugating enzyme activities in liver. However, BT may not affect the disposition and efficacy of tolbutamide.     

Salacia oblonga ameliorates hypertriglyceridemia and excessive ectopic fat accumulation in laying hens

Ethnopharmacological relevance

Salacia oblonga root (SOR) is an Ayurvedic medicine for obesity and diabetes, those are associated with glucose and lipid metabolism.

Aim of the study

SOR has been demonstrated previously to improve glucose and lipid metabolism in animal models of obesity and diabetes and to be a peroxisome proliferator-activated receptor-alpha activator. However, the anti-obesogenic and anti-diabetic mechanisms of SOR are still not largely understood. Here, we investigated the effects of SOR on lipid metabolism using laying hen, a unique animal model with a very high rate of triglyceride synthesis in the liver.

Materials and methods

Laying hens and preadolescent pullets were treated with the layer ration containing 0%, 0.5%, or 1% SOR water extract for 4 weeks. Biochemical variables were determined enzymatically.

Results

Laying hens showed much higher fasted triglyceride concentrations (increased by 5–13 folds) in plasma, liver, skeletal muscle and heart than pullets. 1% SOR extract treatment inhibited body weight increase without affecting food intake. Importantly, this treatment substantially attenuated hypertriglyceridemia and inhibited increases in triglyceride contents in the non-adipose tissues. However, SOR extract did not induce change in plasma glucose concentration. Moreover, SOR extract did not alter all variables in pullets.

Conclusions

These results demonstrate that SOR ameliorates hypertriglyceridemia and excessive ectopic fat accumulation in laying hens. These findings suggest that the triglyceride-lowering property is one of the primary effects of SOR, possibly via hepatic mechanisms.     

Hepatoprotective effect of the ethanol extract of Vitis thunbergii on carbon tetrachloride-induced acute hepatotoxicity in rats through anti-oxidative activities

Ethnopharmacological relevance

Vitis thunbergii var. taiwaniana are traditionally used for the treatment of diarrhea, fracture and injury, jaundice, and hepatitis in Taiwan.

Aim of the study

The hepatoprotective activity of its plant extracts seems to be been associated with its antioxidant activity. This paper aims to investigate the in vitro and in vivo antioxidant effects of the ethanol extract of Vitis thunbergii (EVT).

Materials and methods

In HPLC analysis, the fingerprint chromatogram of EVT was established. Antioxidant ability of EVT was investigated by employing several established in vitro methods. In vivo antioxidant activity was tested against CCl₄-induced toxicity in mice. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected in the blood to indicate hepatic injury. Product of lipid peroxidation (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and reduced glutathione (GSH) contents were evaluated for oxidative stress in hepatic injury. Moreover, histopathological observation was assayed for the degree of hepatic injury.

Results

EVT exhibited strong antioxidant ability in vitro. After oral administration of EVT significantly decreased ALT and AST, and ameliorated the oxidative stress in hepatic tissue and increased the activity of CAT, SOD, GPx, and GSH. Serum tumor necrosis factor-alpha (TNF-α), interleukin−1β (IL-1β), and nitric oxide (NO) were decreased in the group treated with CCl₄ plus EVT. Western blotting revealed that EVT blocked protein expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in CCl₄-treated rats, significantly. Histopathological examination of livers showed that EVT reduced fatty degeneration, cytoplasmic vacuolization and necrosis in CCl₄-treated rats.

Conclusion

This study suggests that EVT possesses antioxidant effects in vitro and hepatoprotective effect on acute liver injuries induced by CCl₄in vivo, and the results suggested that the effect of EVT against CCl₄-induced liver damage is related to its antioxidant properties.     

Effect of polypeptide 2B1 on condition of dampness pattern in rats in terms of Traditional Chinese Medicine

Objective

This study investigated how polypeptide 2B1 is involved in regulating and governing dampness in rat models with dampness pattern defined in terms of Traditional Chinese Medicine.

Methods

We randomly divided 48 SPF 10-week-old male Sprague-Dawley (SD) rats into a normal group, normal + Aristolochic acid I (AA-I) for 5 min group, normal + AA-I for 60 min group, dampness pattern group (DS-Group), dampness pattern + AA-I for 5 min group, and dampness pattern + AA-I for 60 min group. Groups were then treated accordingly. We took out the lung, stomach, liver, spleen, kidney, large intestine, and small intestine tissues to detect gene and protein expression of organic anion transporter polypeptide 2B1 (OATP2B1).

Results

Gene expression of OATP2B1 in spleen, kidney, and small intestine of rats with dampness pattern was lower than that in normal rats (P<0.05). The gene expressions of OATP2B1 in liver, stomach, large intestine, and small intestine were lower than that in control rats at different time points after being stimulated by AA-I (P<0.05).

Conclusion

There is coordination among multiple viscera in handling the condition of dampness, and the mechanism underlying the action may rely on regulating the expression of OATP2B1.     

The protective effect of Zizyphus jujube fruit on carbon tetrachloride-induced hepatic injury in mice by anti-oxidative activities

Aim of the study

The study was aimed to investigate the protective effect against hepatic injury induced by CCl₄ for the ethanolic extract of FZJ.

Materials and methods

The alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected as biomarker in blood of hepatic injury. Product of lipid peroxidation (MDA), activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), and reduced glutathione (GSH) contents were evaluated for oxidative stress in hepatic injury. Moreover, histopathological observation was assayed at the degree of hepatic injury.

Results

After administrated the FZJ, the dose of 200 mg/kg significantly decreased ALT and AST, and attenuated histopathology of hepatic injury, and ameliorated the oxidative stress in hepatic tissue. Partly assayed indexes were ameliorated after administrated FZJ at the dose of 100 mg/kg.

Conclusion

These results indicated that hepatic protective effects of FZJ were very relevant to modulate the oxidative stress in hepatic injury.