Evaluation of chemopreventive effect of Fumaria indica against N-nitrosodiethylamine and CCl_4-induced hepatocellular carcinoma in Wistar rats

Objective:To investigation the chemopreventive potential of Fumaria indica（F.indica） extract（FIE） on N-nitrosodiethylamine and CCl4-induced hepatocarcinogenesis in Wislar rats.Methods:The experimental animals were divided into six groups（n=6）.Hepatocellular carcinoma was induced by single intraperitoneal injection of N-nitrosodiethylamine（NDEA） in normal saline at a dose of 200 mg/kg body weight followed by weekly subcutaneous injections of CCl4（3 mL/kg/week） for 6 weeks,as the promoter of carcinogenic effect.After administration of the carcinogen,200 and 400 mg/kg of FIE were administered orally once a day throughout the study.At the end of 20 weeks,the body weight,liver weight and relative liver weight were measured.The percentage of nodule incidence and liver cancer markers such as aspartate transaminase（AST）,alanine transaminase（ALT）,alkaline phosphatase（ALP）,γ-glutamyl transferase（γ-GT）,total bilirubin level（TBL）,α-feto protein（AFP） and carcinoembryonic antigen were estimated along with histopathological investigation in experimental groups of rats. Results:Obtained results demonstrated that the cotreatment with FIE significantly prevented the decrease of the body weight and also increased in relative liver weight caused by NDEA. The treatment with FIE significantly reduced the nodule incidence and nodule multiplicity in the rats after NDEA administration.The levels of liver cancer markers such as AST,ALT,ALP,γ-glutamyl transferase,TBL,AFP and carcinoembryonic antigen were substantially increased by NDEA treatment.However,FIE treatment significantly reduced the liver injury and restored the entire liver cancer markers.Histological observations of liver tissues too correlated with the biochemical observations.Conclusions:These finding powerfully supports that F.indica exert chemopreventive effect by suppressing the tumor burden and restoring the activities of hepatic cancer marker enzymes on NDEA and CCl4-induced hepatocarcinogenesis in Wistar rats.

Polyphenolic extract of Sorghum bicolor grains enhances reactive oxygen species detoxification in N-nitrosodiethylamine-treated rats

Reactive oxygen species detoxification potentials of Sorghum bicolor polyphenolic extract was investigated in the liver of N-nitrosodiethylaminetreated rats.Male rats,weighing(135±5.5)g were completely randomized into 7 groups(A–G)of five rats each.Rats in C,D,E and F were administered orally once daily at 24-h interval for 7 d with 500,125,250 and 500 mg/kg body weight of polyphenolic extract of S.bicolor,respectively.Group G was given 100 mg/kg body weight of vitamin C.On the sixth day,groups B,D,E,F and G were administered with 100 mg/kg body weight N-nitrosodiethylamine(NDEA).Group A,which served as the control was treated like the test groups except,that the animals received distilled water only.Reactive oxygen species detoxifying enzymes(superoxide dismutase,catalase,glutathione peroxidase,glutathione reductase and glucose 6-phosphate dehydrogenase)activities were significantly(P<0.05)induced by S.bicolor.These inductions significantly(P<0.05)attenuated the NDEA-mediated decrease in reactive oxygen species detoxifying enzymes and compared favourably with vitamin C.NDEA-mediated elevation in the concentrations of oxidative stress biomarkers;malondialdehyde,conjugated dienes,lipid hydroperoxides,protein carbonyl and percentage DNA fragmentation were significantly(P<0.05)lowered by S.bicolor polyphenolic extract.Overall,the results obtained from this study revealed that the polyphenolic extract of S.bicolor grains enhanced the detoxification of reactive oxygen species in NDEA-treated rats.The polyphenols also prevented the peroxidation of lipid,oxidation of proteins as well as fragmentation of DNA component in the liver of rats and hence gave the evidence of possible prophylactic potentials of S.bicolor grains.©2013 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

Protective effect of Genistein against N-nitrosodiethylamine(NDEA)-induced hepatotoxicity in Swiss albino rats

In the present study,we studied the effect of Genistein against the hepatotoxicity induced by N-nitrosodiethylamine（NDEA）.NDEA is present in almost all kinds of food stuff and has been reported to be a hepatocarcinogen.The male rats were exposed to NDEA（0.1 mg/mL） dissolved in drinking water separately and along with 25,50,100 mg/mL of Genistein for 21 days.The activities of serum glutamic oxaloacetic transaminase（SGOT）,serum glutamic pyruvic transaminase（SGPT）.alkaline phosphatase（ALP） and lactate dehydrogenase（LDH） were measured in blood serum.Lipid peroxidation,protein carbonyl content,micronucleus frequency and DNA damage（Comet assay） were performed on rat hepatocytes.The results of the study reveal that the treatment of NDEA along with Genistein showed a significant dose-dependent decrease in the levels of blood serum enzymes i.e.,SGOT,SGPT,ALP and LDH（P〈0.05）.The HE staining of histological sections of the liver also revealed a protective effect of Genistein.A significant dose-dependent reduction in the lipid peroxidation and protein carbonyl content was observed in rats exposed to NDEA（0.1 mg/mL） along with Genistein（P〈0.05）.The results obtained for the comet assay in rat hepatocytes showed a significant dose-dependent decrease in the mean tail length（P〈0.05）.Thus the present study supports the hepatoprotective role of Genistein.

<i>N</i>–nitrosodiethylamine cytochrome P450 induction and cytotoxicity evaluation in primary cultures of rat hepatocytes

The primary routes of potential human exposure to N-nitrosodiethylamine (NDEA) are ingestion, inhalation, and dermal contact. Air, diet and smoking contribute to potential human exposure at levels of a few μg of NDEA/day. Potential exposure depends on the ability of the nitrosamines to migrate from the product into the body. The first step in the metabolic degradation of NDEA by cytochrome oxidase (CYPs) enzymes is the introduction of a hydroxyl group and in human esophage and liver CYP2A3 and CYP2E1 participate on this metabolism. Measuring cytotoxicity in female rat primary hepatocytes cultures, were used to understand the CYP induction and metaboli-zation correlated with low NDEA concentrations. We observed that NDEA at different concentrations in the absence of CYPs inducers, was able to induce CYP2B1, CYP2B2, CYP2E1, CYP3A1 and CYP4A3. A positive NDEA synergistic effect on the levels of mRNA, was observed in the presence of pyrazole (300 μM) for CYP2B1 and CYP2B2 and for pregnenolone 16- carbonitrile (0.15 μM) for CYP2E1. Negative NDEA synergistic effects were observed for ethanol (0.3%) for CYP3A1, pyrazol (300 μM) for CYP2A1 and CYP2E1, and phenobarbital (1 mM) for CYP2A1. These facts are extremally important once that these metabolites can be directly related to the primary DNA lesions. We consider that studies to elucidate the biological factors that determine the shape of the dose-response curve are crucial for low-dose extrapolations of risk.

Evaluation of the Liver Cancer Prevention of Anthocyanin Extracts from Mulberry (<i>Morus alba</i>L.) Variety PR-01

This study aims to evaluate the preventive effects of anthocyanins extracts (MAEs) from mulberry variety PR-01 against N-nitrosodiethylamine (NDEA)-induced hepatocarcinogenesis in rats. It was found that 150 mg·kg-1 MAEs treatment significantly reduced the NDEA-induced hepatic nodules incidence and hepatocellular carcinoma incidence by 58.30% and 41.70% compared to the model group. Meanwhile, MAEs significantly restored the elevated the liver function enzymes, inhibited the tumor necrosis factor alpha and interleukin-6 levels, elevated the serum interleukin-10 and interferon-γ and increased hepatic glutathione-S-transferase and UDP-glucuronosyltransferase 2B1 enzyme activity. Moreover, 150 mg·kg-1 MAEs supplement enhanced glutathione content and the activities of superoxide dismutase, catalase, glutathione peroxidase activities but reduced the malondialdehyde and thiobarbituric acid-reactive substances content by 37.90% and 44.52%. Furthermore, MAEs pretreatment maintained nuclear factor erythroid 2-related factor 2 (Nrf2), Kelch-like ECH-associated protein 1, heme oxygenase-1, and NAD(P)H: quinine oxidoreductase1 stimulation and inhibited the expression of TNF-α, nuclear factor-kappaB (NF-κB), and cyclooxygenase-2 (COX-2), indicating that MAEs exhibit effectively prevention effects against liver cancer via decreased lipid peroxidation, induced Nrf2-mediated antioxidant enzymes and attenuating the inflammatory mediators COX-2 through NF-κB pathway. Thus, MAEs of mulberry variety PR-01 may be used as a good functional dietary supplement against liver cancer.

Protective Effect of Ethanolamine on Hepatic Preneoplastic Alterations Induced by the Administration of <i>N</i>-Nitrosodiethylamine in Rats

The effects of exogenously administered ethanolamine (Etn) on the N-nitrosodiethylamine (NDA)-induced formation of hepatic lesions in rats were investigated. Sprague-Dawley rats were intraperitoneally administered NDA (100 mg/kg body weight) at 7-day intervals, and the animals were allowed free access to water containing Etn (15 or 50 mg/L) for 35 days. NDA-induced hepatic lesions were assessed according to the number of nodules detectable on the liver surface, areas of clear cell foci observed on histopathological thin sections, hydroxyproline levels in liver homogenates, and blood biochemical marker levels. Compared with those from control rats that were not administered Etn, livers from Etn-exposed rats had significantly fewer surface nodules and smaller areas of clear cell foci, indicating that Etn prevented or delayed the formation of preneoplastic cell alterations. Hydroxyproline levels in livers were significantly lower in Etn-treated rats, indicating that the chemical prevented the formation of fibrotic alterations. The protective effects of Etn on NDA-induced hepatic lesions were demonstrated by changes in blood biochemical marker levels. These results suggest that Etn can protect against cellular alterations induced by a carcinogenic chemical, possibly by enhancing hepatic phospholipid synthesis.