No abstract

Cleistocalyx nervosum var. paniala, an edible fruit found in Northern Thailand, contains high amounts of phenolic compounds with in vitro antioxidant activity. The aqueous extract of the ripe fruit was evaluated for its safety and beneficial effects using genotoxicity and toxicity tests. The C. nervosum extract was not only non-mutagenic in Salmonella typhimurium strains TA98 and TA100 in the presence and absence of metabolic activation, but exhibited also moderate antimutagenic effects against aflatoxin B1 and 2-amino-3,4-dimethylimidazo[4,5-f]quinoline-induced mutagenesis. Electrospray ionization-mass spectrometric analysis revealed the major anthocyanins, which included cyanidin-3,5-diglucoside, cyanidin-3-glucoside and cyanidin-5-glucoside. The administration of C. nervosum at concentration of 5,000 mg/kg bw did not induce acute toxicity in rats. A liver micronucleus test was performed to detect clastogenicity and anticlastogenicity. The extract in the dose of 1,000 mg/kg did not cause micronucleus formation in the liver of rats. Furthermore, in rats administered 100–1,000 mg/kg of the extract, no anticlastogenic effect against diethylnitrosamine-induced hepatic micronucleus formation was observed. These studies provide data concerning the safety and antimutagenic potency of an aqueous extract of C. nervosum fruit.

Purpose: To study the effect of Cleistocalyx nervosum extract (CE) on diethylnitrosamine (DEN) and phenobarbital (PB) induced oxidative stress in early stages of rat hepatocarcinogenesis. Materials and Methods: Male Wistar rats were divided into 4 groups, with Group 1 as a negative control and Group 2 was a positive control receiving DEN injections once a week and PB in drinking water for 6 weeks. Two weeks before DEN initiation and PB treatment, Groups 3 and 4, were fed with 500 and 1000 mg/kg of CEs, respectively, for 8 weeks. Results: A number of GST-P-positive foci, preneoplastic lesions, in the liver were markedly increased in carcinogen administered rats, but was comparatively decreased in rats treated with 1000 mg/kg of CE. The CE reduced malondialdehyde in serum and in the livers of rats treated with DEN and PB. Moreover, CE significantly increased the activities of glutathione peroxidase and catalase in rat liver. Conclusions: CE appeared to exert its chemopreventive effects by modulating antioxidant status during DEN and PB induced early stages of hepatocarcinogenesis in rats.

Use of natural products is one strategy to lessen cancer incidence. Rice bran, especially from colored rice, contains high antioxidant activity. Cancer chemopreventive effects of hydrophilic purple rice bran extract (PRBE) and white rice bran extract (WRBE) on carcinogen-induced preneoplastic lesion formation in livers of rats were investigated. A 15-week administration of PRBE and WRBE did not induce hepatic glutathione S-transferase placental form (GST-P) positive foci formation as the biomarker of rat hepatocarcinogenesis. PRBE and WRBE at 500 mg/kg body weight significantly decreased number and size of GST-P positive foci in diethylnitrosamine (DEN)-initiated rats. The number of proliferating nuclear antigen positive hepatocytes were also reduced in preneoplastic lesions in both PRBE and WRBE fed DEN-treated rats. Notably, the inhibitory effect on GST-P positive foci formation induced by DEN during the initiation stage was found only in rats treated by PRBE for five weeks. Furthermore, PRBE attenuated the expression of proinflammatory cytokines involving genes including TNF-α, iNOS, and NF-κB. PBRE contained a higher number of anthocyanins and other phenolic compounds and vitamin E. PRBE might protect DEN-induced hepatocarcinogenesis in rats via attenuation of cellular inflammation and cell proliferation. Anthocyanins and other phenolic compounds, as well as vitamin E, might play a role in cancer chemopreventive activity in rice bran extract.

Objective: The increasing consumer awareness of food, which can provide health benefits and potentially aid disease prevention, has become the driving force of the functional food market. Accordingly, the aim of this study was to investigate the effects of chicken genotype on the macronutrient content, bioactive peptide content, and antioxidant capacity within different breast meat.Methods: In this experiment, three genotypes of chicken, Thai indigenous, black-boned, and broiler (control), were reared with commercial feed under the same conditions. Thirty chickens were slaughtered at typical market age and the breasts were separated from the carcass to determine macronutrient content using the AOAC method. The antioxidant capacities of the chicken breasts were evaluated by in vitro antioxidant assays and the protein pattern was investigated using gel electrophoresis. Carnosine and anserine, which have antioxidant properties in animal tissue, were determined using high performance liquid chromatography.Results: The results showed that breast meat from Thai indigenous chickens had a greater macronutrient content and higher antioxidant capacity compared with the other genotypes (p<0.05). The protein pattern was similar between genotypes, however Thai indigenous chickens had the greatest myosin and actin content (p<0.05). In addition, carnosine and anserine values were greatest in the black-boned and Thai indigenous chickens compared with the broiler genotype (p<0.05).Conclusion: Thai indigenous chicken breast meat may be classified as a functional food as it has good nutritional value and is rich in antioxidant peptides.