Modulatory effect of troxerutin on biotransforming enzymes and preneoplasic lesions induced by 1,2-dimethylhydrazine in rat colon carcinogenesis.

Colon cancer is the third most global oncologic problem faced by medical fraternity. Troxerutin, a flavonoid present in tea, coffee, cereal grains, and a variety of fruits and vegetables, exhibits various pharmacological and biological activities. This study was carried out to investigate the effect of troxerutin on xenobiotic metabolizing enzymes, colonic bacterial enzymes and the development of aberrant crypt foci (ACF) during 1,2-dimethylhydrazine (DMH) induced experimental rat colon carcinogenesis. Male albino Wistar rats were randomly divided into six groups. Group 1 served as control. Group 2 received troxerutin (50 mg/kg b.w., p.o. every day) for 16 weeks. Groups 3-6 received subcutaneous injections of DMH (20 mg/kg b.w.) once a week, for the first four weeks. In addition, groups 4-6 received different doses of troxerutin (12.5, 25, 50 mg/kg b.w., p.o. every day respectively) along with DMH injections. Our results reveal that DMH treated rats exhibited elevated activities of phase I enzymes such as cytochrome P450, cytochrome b5, cytochrome P4502E1, NADPH-cytochrome P450 reductase and NADH-cytochrome b5 reductase and reduced activities of phase II enzymes such as glutathione-S-transferase (GST), DT-diaphorase (DTD) and uridine diphospho glucuronyl transferase (UDPGT) in the liver and colonic mucosa of control and experimental rats. Furthermore, the activities of fecal and colonic mucosal bacterial enzymes, such as ß-glucronidase, ß-glucosidase, ß-galactosidase and mucinase were found to be significantly higher in DMH alone treated rats than those of the control rats. On supplementation with troxerutin to DMH treated rats, the alterations in the activities of the biotransforming enzymes, bacterial enzymes and the pathological changes were significantly reversed, the effect being more pronounced when troxerutin was supplemented at the dose of 25 mg/kg b.w. Thus troxerutin could be considered as a good chemopreventive agent against the formation of preneoplastic lesions in a rat model of colon carcinogenesis.

Antiproliferative efficacy of hesperetin (citrus flavanoid) in 1,2-dimethylhydrazine-induced colon cancer.

Cancer is the second leading cause of death worldwide and is increasing at an alarming rate. The present study was to evaluate the antiproliferative effects of hesperetin, a flavonoid commonly found in many herbal medicines and foods, on aberrant crypt foci (ACF), argyrophylic nucleolar organizer regions (AgNORs) and proliferating cell nuclear antigen (PCNA) in 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in rats. Rats were given subcutaneous injections of DMH (20 mg/kg body weight) weekly for 15 weeks to induce carcinogenesis, and hesperetin was administered orally at the dose of 20 mg/kg body weight. DMH exposure alone produced a high incidence of ACF and showed positive staining for PCNA and AgNORs in colonic tissues. Supplementation with hesperetin lowered the PCNA labeling index and suppressed the formation of ACF in the rats with colon cancer. These results clearly reveal that dietary hesperetin possesses antiproliferative ability against chemically induced colon tumourigenesis.

Dietary d-limonene alleviates insulin resistance and oxidative stress-induced liver injury in high-fat diet and L-NAME-treated rats.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is one of the most common etiologies of chronic liver disease worldwide. The pathogenesis of metabolic syndrome associated with NAFLD is still under debate. AIM OF THE SCOPE: This study has investigated the hepatic biochemical and histological changes and also insulin resistance in metabolic syndrome associated with NAFLD. METHODS: Young male Wistar rats fed a high-fat diet (HFD 42.2% beef tallow) together with N ( ω )-nitro-L-arginine methyl ester (L-NAME; 80 mg/L in drinking water) for 8 weeks and subsequently with 2% d-limonene for the final 4 weeks. RESULTS: HFD-fed rats treated with L-NAME showed increased systolic blood pressure, heart rate, fasting blood glucose, plasma insulin, hepatic marker enzymes, hepatic lipids, circulatory lipid peroxidation by-products, and hepatic phase I enzyme activities with decreased circulatory nonenzymic antioxidant concentrations and hepatic phase II enzyme activities. Dietary supplementation with d-limonene reversed the HFD and L-NAME-induced changes and restored pathological alteration of liver and pancreas. CONCLUSIONS: These data provide new insights into the therapeutic approach of d-limonene against the development of the metabolic syndrome associated with NAFLD.

Chemopreventive efficacy of gallic acid, an antioxidant and anticarcinogenic polyphenol, against 1,2-dimethyl hydrazine induced rat colon carcinogenesis.

Colon cancer is a major cause of morbidity and mortality in developed and developing countries and its etiology is known to be a combination of hereditary, environmental, dietary factors and lack of physical activity. Chemoprevention offers a novel approach to control the incidence of colon cancer. Gallic acid (GA) is a polyphenol widely present in tea and other plants which is popularly used in the traditional medicine of China. The present study was to evaluate the efficacy of GA supplementation on tissue lipid peroxidation and antioxidant defense system in 1,2-dimethyhydrazine (DMH) induced colon carcinogenesis in male Wistar rats. The rats were assorted into six groups, viz., group1 control rats received modified pellet diet; group 2 rats received GA (50 mg/kg body weight) orally along with modified pellet diet; group 3 rats received DMH (20 mg/kg body weight) subcutaneously once a week for the first 15 weeks; groups 4, 5 and 6 rats received GA along with DMH during the initiation, post- initiation stages and the entire period of study respectively. All the rats were sacrificed at the end of 30 weeks and the tissues were evaluated biochemically. We observed decreased lipid peroxidation (LPO) products such as thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOH) and conjugated dienes (CD) and diminished levels of antioxidants such as superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), glutathione reductase (GR) and glutathione peroxidase (GPx) in the tissues of DMH treated rats, which were elevated significantly on GA supplementation. Moreover, enhanced activity of ascorbic acid and alpha-tocopherol levels were also observed in DMH alone treated rats which were significantly reduced on GA supplementation. Our results suggest that GA could exert a significant chemopreventive effect on DMH induced colon carcinogenesis.

Silibinin ameliorates oxidative stress induced aberrant crypt foci and lipid peroxidation in 1, 2 dimethylhydrazine induced rat colon cancer.

Pharmacological intervention to reduce CRC mortality entails the use of oral agents that can avert carcinogenesis. Silibinin, a major component of silymarin isolated from Silybum marianum (L.) was found to possess attractive remedial features. An in vivo study was designed to elucidate the effect of silibinin on the formation of 1, 2 dimethylhydrazine (DMH) induced aberrant crypt foci (ACF), tissue lipid peroxidation (LPO) and enzymic antioxidants status during different phases of experimental colon cancer. DMH alone treated rats showed significantly (p < 0.05) increased size and number of ACF, accompanied by decreased LPO and enzymic antioxidant activities. Administration of silibinin to DMH treated rats inhibited mean colonic ACF and multi-crypt AC/foci and also improved the levels of enzymic antioxidants in a time dependent manner. Histologically no obvious sign of neoplasia was observed in silibinin supplemented DMH treated rats during the various stages of carcinogenesis. Our results show that silibinin possesses potent chemopreventive activity against colon carcinogenesis.

Hesperetin exerts dose dependent chemopreventive effect against 1,2-dimethyl hydrazine induced rat colon carcinogenesis.

Colon cancer is still one of the leading causes of death in USA and is increasing at an alarming rate in Asia. It is one of the major causes of death in industrialized countries, and its etiology is known to be a combination of hereditary, environmental, dietary factors and lack of physical activity. Chemoprevention plays a potential role in colorectal cancer. The present study was performed to evaluate the efficacy of hesperetin supplementation on colonic aberrant crypt foci, lipid peroxidation and antioxidant defense system in 1,2-dimethylhydrazine (DMH) induced colon carcinogenesis in male Wistar rats. The rats were segregated into six groups viz., group 1, control rats received modified pellet diet; group 2 rats received modified pellet diet along with hesperetin (30 mg/kg body weight/day); groups 3-6 administrated DMH (20 mg/kg body weight) subcutaneous injection once a week for the first 4 weeks; in addition groups 4-6 received hesperetin at three different doses of 10, 20 and 30 mg/kg body weight/day for 16 weeks. All the rats were sacrificed at the end of the experimental period of 16 weeks. Increased tumor incidence and increased number aberrant crypt foci (ACF) accompanied by a decrease in the tissue lipid peroxidation, glutathione S-transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) activities were observed in DMH-treated rats. Administration of hesperetin to DMH treated rats significantly decreased the tumor incidence, the number of aberrant crypt foci with simultaneous enhancement of tissue lipid peroxidation, GST, GPx, SOD, and CAT activities. The results of this study suggest that hesperetin at a dose of 20 mg/kg body weight showed a significant beneficial effect against chemically induced colonic carcinogenesis in rats as compared to the other two doses.

Resveratrol attenuates 1,2-dimethylhydrazine (DMH) induced glycoconjugate abnormalities during various stages of colon carcinogenesis.

Although a myriad of health promoting effects has been attributed to resveratrol (Res) (3,5,4'-trihydroxy-trans-stilbene), a phytoalexin, the most interesting is its anticancer property. The aim of this work was to elucidate the effectiveness of Res against cellular transformation (glycoconjugate alterations) initiated by 1,2-dimethylhydrazine (DMH), a colon specific carcinogen. Group 1 were control rats, group 2 were control rats that received Res (8 mg/kg body weight orally every day), rats in groups 3-6 were treated weekly with DMH (20 mg/kg body weight, subcutaneously x 15 times). In addition, groups 4-6 received Res (as in group 2) in three dietary regimens: initiation (I), post-initiation (PI) and entire period (EP). At the end of the 30 week experimental period in DMH alone exposed rats, altered levels of glycoconjugates (total hexoses, fucose, hexosamine and sialic acid) were observed in liver, intestine and colon tissues. Of the three dietary regimens of Res, the entire period supplementation significantly (p < 0.01) modulated the levels of glycoconjugates and reduced the incidence of adenoma and adenocarcinoma. These findings suggest that Res may extend its chemopreventive effect by restoring the alteration in glycoconjugates that are thought to be involved in the colonic malignant transformation process in this experimental model.

Mouse recombinant leptin protects human hepatoma HepG2 against apoptosis, TNF-alpha response and oxidative stress induced by the hepatotoxin-ethanol.

Obesity is a risk factor for hepatocellular carcinoma (HCC) complicated with alcoholic liver disease (ALD) and cryptogenic cirrhosis. Leptin is a 16-kDa antiobesity hormone secreted mainly by adipocytes. The role of leptin on alcohol-mediated effects in cell line is yet to be unraveled. Therefore, we investigated the effect of leptin against ethanol-elicited cytoxicity in human hepatoma cell lines (HepG2). HepG2 cells were treated with leptin (31.2 nM), ethanol (500 mM), ethanol+leptin and untreated cells served as control. 48 h after treatment, cell viability, apoptosis, TNF-alpha secretory response and oxidative damage were analysed. Our results suggest that leptin at a concentration of 31.2 nM prevents ethanol elicited cytotoxicity as evidenced by MTT and trypan blue dye exclusion assay. Leptin also inhibited ethanol-induced apoptosis, which was confirmed by [(3)H] thymidine uptake and cell cycle analysis using propidium iodide (PI) staining. Further, simultaneous leptin treatment along with ethanol showed protection against ethanol mediated cellular damage as indicated by significantly decreased levels of reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) and significantly increased levels of reactive nitrogen species (RNS), reduced glutathione (GSH) and elevated activities of superoxide dismutase (SOD) and catalase (CAT). In addition, leptin downregulated the secretion of tumor necrosis factor-alpha (TNF-alpha) by ethanol-induced HepG2 cells. Our results demonstrate that simultaneous leptin treatment along with ethanol could be useful in preventing the damage produced by ethanol, which might be of therapeutic interest.

Protective effect of quercetin on nicotine-induced prooxidant and antioxidant imbalance and DNA damage in Wistar rats.

We have investigated the protective effect of quercetin (QN) against nicotine-induced prooxidant and antioxidant imbalance in circulation, lung, liver and kidney of experimental rats. The protective effect of QN was compared with N-acetylcysteine (NAC), a well-known antioxidant. Male albino rats of Wistar stain were used for the experimental study. Lung toxicity was induced by subcutaneous injection of nicotine at a dose of 2.5mg/kg body weight (5 days a week, for 22 weeks) and QN was given simultaneously by intragastric intubations for 22 weeks. The body weight gain of rats during experimental period was significantly decreased in nicotine treated group, whereas QN co-treated rats significantly increased in their body weight. The levels of lipid peroxidative indices viz., thiobarbituric acid reactive substances and hydroperoxides, and nitric oxide in circulation, lung, liver and kidney of nicotine-treated rats were increased significantly when compared to normal, which were brought down to near normal in QN co-treated group. Endogenous antioxidant status viz., superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione were found to be significantly decreased in circulation, lung, liver and kidney of nicotine-treated group, which were significantly increased in QN-administered groups. The extent of DNA damage (evaluated by comet assay) was significantly increased in circulatory blood of nicotine-treated rats, which was effectively brought down by QN treatment. The protective effect of QN against nicotine toxicity was comparable to that of NAC. Our data suggest that QN exerts its protective effect by modulating the extent of lipid peroxidation and augmenting antioxidant defense system and thus protects the DNA in experimental animals.

Hemidesmus indicus protects against ethanol-induced liver toxicity.

Alcoholic liver disease (ALD) is one of the most common diseases in modern society. A large number of studies are in progress aiming to identify natural substances that would be effective in reducing the severity of ALD. Although there are currently a number of drugs on the market, their long-term use can have numerous side effects. Hemidesmus indicus is an indigenous Ayurvedic medicinal plant used in soft drinks in India. In this study, we examined the effects of its ethanolic root extract on experimental liver damage in order to evaluate its hepatoprotective effects against hepatotoxicity induced in rats by ethanol at a dosage of 5 g/kg body weight for 60 days. The H. indicus root extract was given at a dose of 500 mg/kg body weight for the last 30 days of the experiment. The animals were monitored for food intake and weight gain. The liver was analysed for the degree of lipid peroxidation using thiobarbituric acid reactive substances (TBARS) and antioxidant status using the activities of glutathione-dependent enzymes. The degree of liver damage was analysed using serum marker enzyme activities, the total protein, albumin, globulin, ceruloplasmin and liver glycogen contents, and the A/G ratio. The Fourier transform infrared spectra (FT-IR) of the liver tissues were recorded in the region of 4000-400 cm(-1). The ethanol-fed rats showed significantly elevated liver marker enzyme activities, lipid peroxidation levels and reduced antioxidant levels as compared to the control rats. Oral administration of H. indicus for the latter 30 days resulted in an increased food intake and weight gain, decreased TBARS levels, near normal levels of glutathione-dependent enzymes, increased total protein, albumin, globulin and liver glycogen contents, an increased A/G ratio, and decreased liver marker enzyme activities and ceruloplasmin levels. The relative intensity of the liver FT-IR bands for the experimental groups were found to be altered significantly (p < 0.05) compared to the control samples. For the group that had H. indicus co-administered with ethanol, the intensity of the bands was near normal. Moreover, the results of the FT-IR study correlated with our biochemical results.

Dose-dependent effect of oregano (Origanum vulgare L.) on lipid peroxidation and antioxidant status in 1,2-dimethylhydrazine-induced rat colon carcinogenesis.

Colon cancer is a major cause of morbidity and mortality in developed and developing countries. Diet and dietary constituents play a major role in the aetiology of colon cancer. We have investigated the effect of an aqueous extract of oregano (Origanum vulgare. L.) on lipid peroxidation and anti-oxidant status in 1,2-dimethylhydrazine (DMH)-induced rat colon carcinogenesis. We aimed to identify the important antioxidants present in Indian oregano using RP-HPLC. DMH (20 mgkg(-1)) was administered subcutaneously once a week for the first four weeks and then discontinued. Oregano was supplemented every day orally at a dose of 20, 40 or 60 mgkg(-1) to different groups of rats for 15 weeks. After this time the rats were killed and the colons were examined visually and evaluated biochemically. The levels of lipid peroxidation products, such as thiobarbituric acid reactive substances and conjugated dienes were significantly higher in the liver whereas in caecum and colon the levels were lower in DMH-treated animals as compared with control rats. The levels of the anti-oxidants superoxide dismutase, catalase, reduced glutathione, glutathione reductase, glutathione peroxidase and glutathione-S-transferase were decreased in DMH-treated rats, but were significantly reversed on oregano supplementation. Oregano supplementation (40 mgkg(-1)) had a modulatory role on tissue lipid peroxidation and antioxidant profile in colon cancer-bearing rats, which suggested a possible anti-cancer property of oregano.

Effect of hesperetin, a citrus flavonoid, on bacterial enzymes and carcinogen-induced aberrant crypt foci in colon cancer rats: a dose-dependent study.

Hesperetin, an important bioactive compound in Chinese traditional medicine, has antioxidant and anticarcinogenic properties. Hesperetin is found in abundance in orange and grape juices (200-590 mg L(-1)) consumed in the daily diet. We have investigated the effect of different doses of hesperetin on faecal and colonic mucosal bacterial enzymes and aberrant crypt foci (ACF) in 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in male Wistar rats. The rats were divided into six groups and were fed a modified pellet diet for 16 weeks. Group 1 served as control and group 2 received the modified pellet diet along with hesperetin (30 mg kg(-1)). The rats in groups 3-6 rats were given a weekly subcutaneous injection of DMH (20 mg kg(-1)) for the first four weeks. Hesperetin was supplemented orally at different doses (10, 20 or 30 mg kg(-1)) for a total of 16 weeks. At the end of the experimental period all rats were killed. In DMH-treated rats, the activity of faecal and colonic mucosal bacterial enzymes, such as beta-glucuronidase, beta-galactosidase, beta-glucosidase, nitroreductase, sulfatase and mucinase, were significantly elevated, but in rats supplemented hesperetin along with DMH the activity was significantly lowered (P < 0.05). The total number of aberrant crypts was significantly increased in unsupplemented DMH-treated rats, while hesperetin supplementation to DMH-treated rats significantly reduced the total number of crypts. The results demonstrated that hesperetin supplementation at a dose of 20 mg kg(-1) played a potent role in suppressing the formation of aberrant crypt foci and reducing the activity of bacterial enzymes in colon cancer.

Inhibitory effect of Hemidesmus indicus and its active principle 2-hydroxy 4-methoxy benzoic acid on ethanol-induced liver injury.

The study evaluates the inhibitory activity of ethanolic root extract of Hemidesmus indicus (H. indicus) and its active principle 2-hydroxy 4-methoxy benzoic acid (HMBA) on liver fibrotic markers and characteristics such as collagen content, matrix metalloproteinases (MMPs) 2 and 9 in ethanol-fed rats. Experimental groups were control, H. indicus (500 mg/kg body weight every day during the last 30 days), HMBA (200 microg/kg body weight every day during the last 30 days), alcohol (5 g/kg body weight by intragastric intubation everyday, i.e. throughout the experimental period of 60 days), alcohol plus H. indicus and alcohol plus HMBA. Ethanol administration significantly increased the levels of liver collagen and hydroxy proline content, cross-linked fluorescence, shrinkage temperature and lipid peroxidation and significantly decreased the solubility of liver collagen and the ascorbic acid content when compared with control rats. On treatment with H. indicus and HMBA the ethanol-fed rats showed significantly reduced levels of liver collagen and hydroxyproline content, cross-linked fluorescence, shrinkage temperature and lipid peroxidation and enhanced solubility of liver collagen and ascorbic acid levels when compared with untreated ethanol-fed rats. MMPs were extracted from the liver of control, H. indicus-treated, HMBA-treated, ethanol-administered, ethanol with H. indicus-coadministered and ethanol with HMBA-coadministered rats. The inhibition was analyzed by gelatin zymography and the percentage of expression was determined by a gel documentation system. The activities of MMPs 2 and 9 were significantly increased in ethanol-supplemented rats. Cotreatment of H. indicus/HMBA with ethanol showed significantly decreased activities of these enzymes when compared with those of the untreated rats. H. indicus/HMBA alone treatment showed no such significant alterations. Thus, our present study reveals the strong inhibitory activity of H. indicus and HMBA on the quantitative and qualitative properties of hepatic collagen and also MMPs involved in the extracellular matrix degradation during ethanol intoxication.

Effect of 2-hydroxy 4-methoxy benzoic acid on an experimental model of hyperlipidaemia, induced by chronic ethanol treatment.

The aim of the present study was to determine the effect of 2-hydroxy 4-methoxy benzoic acid (HMBA), the active principle of Hemidesmus indicus, an indigenous Ayurvedic medicinal plant in India. We investigated the effect of HMBA on hyperlipidaemia induced by ethanol, exploring food intake, body weight, and hepatic and plasma lipids and lipoproteins. Male Wistar rats weighing 130-180 g were given ethanol (5 g kg(-1) p.o.) daily for 30 days. Subsequently, ethanol-fed rats were given HMBA intragastrically at a dose of 200 microg kg(-1) per day for 30 days. At the end of the total experimental period of 60 days, plasma concentrations of total cholesterol (CHO), triglycerides (TG), lipoproteins (LP), phospholipids (PL), free fatty acids (FFA) and lipoprotein lipase (LPL), and hepatic CHO, TG and PL were measured. Treatment of ethanol-fed rats with HMBA significantly decreased plasma CHO, TG, LP, PL and FFA and hepatic CHO, TG and PL, and increased plasma LPL concentrations compared with values in untreated ethanol-fed rats (all P<0.05). Food intake and average body weight at the end of the experimental period were significantly increased by HMBA administration. In conclusion, administration of HMBA decreased lipids and lipoprotein concentrations significantly in an animal model of ethanol-induced hyperlipidaemia.

Antioxidant effect of 2-hydroxy-4-methoxy benzoic acid on ethanol-induced hepatotoxicity in rats.

Alcoholic liver disease (ALD) is one of the most common diseases in society. A large number of studies are in progress to identify natural substances that are effective in reducing the severity of ALD. 2-Hydroxy-4-methoxy benzoic acid (HMBA), the active principle of Hemidesmus indicus, an indigenous Ayurvedic medicinal plant in India, is expected to significantly inhibit the development of liver injury in ethanol administration. It is expected to reduce the severity of liver damage in terms of body weight, hepatic marker enzymes, oxidative stress, antioxidant status and histological changes in ethanol-induced hepatotoxic rats. Hepatotoxicity was induced by administering 20% ethanol (5 g kg(-1) daily) for 60 days to male Wistar rats, which resulted in significantly decreased body weight and an increase in liver-body weight ratio. The liver marker enzymes aspartate transaminase, alanine transaminase, alkaline phosphatase, gamma-glutamyl transpeptidase and lactate dehydrogenase were elevated. In addition, the levels of plasma, erythrocyte and hepatic thiobarbituric acid reactive substances, hydroperoxides and conjugated dienes were also elevated in ethanol-fed rats as compared with those of the experimental control rats. Decreased activity of superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, vitamin C and alpha-tocopherol was also observed on alcohol administration as compared with experimental control rats. HMBA was co-administered at a dose of 200 mug kg(-1) daily for the last 30 days of the experiment to rats with alcohol-induced liver injury, which significantly increased body weight, significantly decreased the liver-body weight ratio, transaminases, alkaline phosphatase, gamma-glutamyl transpeptidase and lactate dehydrogenase, significantly decreased the levels of lipid peroxidative markers, significantly elevated the activity of enzymic and non-enzymic antioxidants in plasma, erythrocytes and liver and also increased levels of plasma and liver vitamin C and alpha-tocopherol at the end of the experimental period as compared with untreated ethanol-administered rats. The histological changes were also in correlation with the biochemical findings. The results suggest that HMBA administration may afford protection against ethanol-induced liver injury in rats.

Antioxidant effect of Hemidesmus indicus on ethanol-induced hepatotoxicity in rats.

The antioxidant effect of the ethanolic root extract of Hemidesmus indicus, an indigenous Ayurvedic medicinal plant used in soft drinks in India, was studied in rats with ethanol-induced hepatotoxicity. Administering 20% ethanol (5 g/kg of body weight/day) for 60 days to male Wistar rats resulted in significantly decreased body weight and increased liver/body weight ratio. The liver marker enzymes, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatae (ALP), gamma-glutamyl transpeptidase (GGT), and lactate dehydrogenase (LDH), were elevated. In addition, the levels of plasma, erythrocyte, and hepatic thiobarbituric acid-reactive substances (TBARS), hydroperoxides (LOOH), and conjugated dienes (CD) were also elevated in ethanol-fed rats as compared to those of the experimental control rats. Decreased activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), vitamin C, and alpha-tocopherol (vitamin E) were also observed in ethanol-administered as compared to control rats. Ethanolic root extract of H. indicus was administered at a dose of 500 mg/kg of body weight/day for the last 30 days of the experiment to rats with ethanol-induced liver injury, which significantly increased body weight, significantly decreased the liver/body weight ratio, AST, ALT, ALP, GGT, and LDH activities, and also the levels of TBARS, LOOH, and CD, significantly elevated the activities of SOD, CAT, GPx, and GSH in plasma, erythrocytes, and liver, and also increased levels of plasma and liver vitamin C and vitamin E at the end of the experimental period as compared to those of untreated ethanol-administered rats. Thus, our data indicate that treatment with H. indicus extract offers protection against free radical-mediated oxidative stress in plasma, erythrocytes, and liver of animals with ethanol-induced liver injury.

Effect of ginger on bacterial enzymes in 1,2-dimethylhydrazine induced experimental colon carcinogenesis.

Colon cancer is becoming increasingly common in Asian countries and still remains the second leading cause of cancer death in the United States. Ginger, a natural spice having both antioxidant and antimutagenic property, is known to inhibit chemical carcinogenesis. This study was designed to investigate the chemopreventive efficacy of ginger on the activity of bacterial enzymes in rats induced colon cancer by 1,2-dimethylhydrazine. Twenty milligrams per kilogram body weight of 1,2-dimethylhydrazine was administered subcutaneously once a week for the first 15 weeks and then discontinued. Ginger (50 mg/kg body weight/per day, oral) was given at the initiation and also at the postinitiation stages of carcinogenesis to 1,2-dimethylhydrazine-treated rats. The animals were killed at the end of 30 weeks. The macroscopic findings in the colon and the incidence of tumors were recorded in each group, and the activity of beta-glucuronidase and mucinase was estimated in the tissues and fecal contents of rats. After a total experimental period of 32 weeks (including 2 weeks of acclimatization), tumor incidence was 100% in 1,2-dimethylhydrazine-treated rats. The incidence of cancer as well as the number of tumors in the colon was significantly reduced both in the initiation and postinitiation stages of carcinogenesis on ginger administration. The activities of bacterial enzymes beta-glucuronidase (proximal colon, distal colon, intestines, liver and colon contents) and mucinase (colon and fecal contents) were significantly elevated in 1,2-dimethylhydrazine-treated rats as compared with the control rats. The increase in beta-glucuronidase activity may augment the hydrolysis of glucuronide conjugates, liberating the toxins, while the increase in the mucinase activity may enhance the hydrolysis of the protective mucins in the colon. Ginger administration to 1,2-dimethylhydrazine-treated rats significantly decreased the incidence and number of tumors as well as the activity of beta-glucuronidase and mucinase. Thus, ginger has a chemopreventive and anticarcinogenic effect against 1,2-dimethylhydrazine-induced colon cancer by virtue of its ability to lower the activities of the microbial enzymes beta-glucuronidase and mucinase.

Effect of hyperleptinaemia on chronic ethanol-induced hepatotoxicity in mice.

Ethanol metabolism is accompanied by generation of free radicals, which stimulate lipid peroxidation. Previous studies have proposed a possible link between leptin and non-alcoholic fatty liver disease; however, the effect of leptin on ethanol-induced liver diseases remains unclear. The aim of the present study was to explore the effect of leptin on ethanol-induced liver injury in mice. Administering ethanol (6.32 g/kg body weight p.o.) to 4-week-old healthy mice for 45 days resulted in significantly elevated levels of plasma leptin, total bilirubin, gamma-glutamyl transpeptidase (GGT), tissue lipid hydroperoxides (LOOH), and lowered levels of tissue vitamins C and E when compared with those of the control mice. Subsequent to the experimental induction of hepatotoxicity (i.e. after the initial period of 30 days) exogenous leptin was administered (230 microg/kg body weight i.p.) every alternate day for 15 days along with the daily dose of ethanol. Leptin administration to control and ethanol-treated mice significantly reduced the weight gain, elevated the plasma levels of leptin, bilirubin, GGT and tissue LOOH, and significantly lowered the levels of tissue vitamins C and E when compared with the untreated control and ethanol-supplemented mice. It is postulated that the increase in systemic leptin levels enhances oxidative stress, and lowers antioxidant defence, leading to the augmented hepatic inflammation observed in alcoholic liver disease.

Dose-response efficacy of caraway (Carum carvi L.) on tissue lipid peroxidation and antioxidant profile in rat colon carcinogenesis.

Colon cancer is a leading cause of cancer death and its prevention is of great interest throughout the world. This study was conducted to examine the efficacy of different doses of dietary caraway (Carum carvi L.) on tissue lipid peroxidation (LPO) and antioxidant profile in rat colon carcinogenesis. Wistar male rats were divided into 6 groups and were fed a modified pellet diet for the whole of 30 weeks. To induce colon cancer, rats were given a weekly subcutaneous injection of 1,2-dimethylhydrazine (DMH) at a dose of 20 mg kg(-1) (based on body weight) for the first 15 weeks. Caraway was supplemented every day orally at doses of 30, 60 and 90 mg kg(-1) for different groups of rats for the total period of 30 weeks. All rats were sacrificed at the end of 30 weeks, the colons were examined visually for masses and were subsequently evaluated histologically. The results showed diminished levels of intestinal, colonic and caecal LPO products, such as conjugated dienes (CD), lipid hydroperoxides (LOOH) and thiobarbituric acid reactive substances (TBARS) and also the antioxidants superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and glutathione reductase (GR) in DMH treated rats, which were significantly reversed (P<0.05) on caraway supplementation. Moreover, enhanced activity of intestinal, colonic and caecal glutathione peroxidase (GPx), glutathione S-transferase (GST) and colonic ascorbic acid and alpha-tocopherol levels were observed in carcinogen-treated rats, which were significantly (P<0.05) reduced on caraway supplementation. Thus, our study showed that caraway supplementation at a dose of 60 mg kg(-1) had a modulatory role on tissue LPO, antioxidant profile and prevented DMH-induced histopathological lesions in colon cancer rats.

Effect of leptin administration on membrane-bound adenosine triphosphatase activity in ethanol-induced experimental liver toxicity.

Hepatic injury elicits intracellular stress that leads to peroxidation of membrane lipids accompanied by alteration of structural and functional characteristics of the membrane, which affects the activity of membrane-bound ATPases. We have explored the effect of leptin on hepatic marker enzyme and membrane-bound adenosine triphosphatases in ethanol-induced liver toxicity in mice. The experimental groups were control, leptin (230 microg kg(-1), i.p. every alternate day for last 15 days), alcohol (6.32 g kg(-1), by intragastric intubation for 45 days), and alcohol plus leptin. Ethanol feeding to mice significantly (P < 0.05) elevated the plasma leptin, alanine transaminase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT) and hepatic lipid hydroperoxides (LOOH), and plasma and hepatic total ATPases, Na(+), K(+)-ATPase and Mg(2+)-ATPase. There was a significant decrease in Ca(2+)-ATPase and reduced glutathione (GSH). Leptin injections to ethanol-fed animals further elevated the levels of hepatic LOOH, plasma and hepatic total ATPases, Na(+), K(+)-ATPase and Mg(2+)-ATPase, while the Ca(2)-ATPase and GSH were decreased significantly. In addition, leptin administration was found to increase the plasma levels of leptin, ALT, ALP, GGT, Na(+) and inorganic phosphorous, and decrease the levels of K(+) and Ca(2+) in ethanol-fed mice. These findings were consistent with our histological observations, confirming that leptin enhanced liver ailments in ethanol-supplemented mice.