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Sub-acute hepatotoxicity was induced in mice by exposure to pesticides. The effect of pretreatment with aqueous black tea extract on lipid peroxidation and antioxidants in the liver was investigated. Administering a combination dose of chlorpyriphos and cypermethrin (20 mg kg(-1) each) on alternate days over a 15-day period to male mice resulted in induction of sub-acute toxicity as reflected by elevated levels of liver damage marker enzymes alkaline phosphatase(ALP), aspartate transaminase(AST) and alanine transaminase(ALT). Significantly elevated levels of lipid peroxidation were observed in the experimental group (group III) as compared with control mice. Decreased activities of superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), total thiol, glutathione peroxidase (GPx), glutathione reductase(GR) and glutathione-S-transferase (GST) were also observed in pesticide-treated as compared to control mice. Aqueous black tea extract was given as a pretreatment to group IV mice at a dose of 200 mg ml(-1) polyphenols before the pesticide dose, which significantly decreased the levels of lipid peroxidation and significantly elevated the activities of SOD, CAT, GSH, total thiol, GPx, GR and GST in liver to levels similar to the controls. Thus, the data offer support for the claim that the central mechanism of pesticide action occurs via changes in cellular oxidative status and shows conclusively that supplementation with black tea extract protects against the free radical-mediated oxidative stress in hepatocytes of animals with pesticide-induced liver injury.

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Advances in civilization processes and industrialization have doubled the release of toxic heavy metals into the environment, consequently elevating their presence in the food chains. Cadmium (Cd) is one of the severe toxic metals widely present in the atmosphere. The major route of animal or human exposure to Cd is through water or food ingestion and inhalation of particles or inhalation of fumes during various industrial processes. Continuous exposure to low levels of Cd results in a gradual deposition in different tissues of the body, causing toxic effects on the liver, kidneys, testes, and other vital organs. The beneficial effect of natural antioxidants against chemical induced toxicity is receiving more attention. Antioxidant-rich dietary products and their function in tempering free radicals produced in the body under different pathological conditions is an active research field. In the current review, we attempted to highlight the current research progress in the field of using antioxidant-rich natural dietary products and their function in mitigating or preventing health issues and tissue damage associated with Cd induced toxicity along with its mechanism.

Different extracts of whole plant of Marrubium vulgare L (Lamiaceae) were investigated for hepatoprotective activity against carbon tetrachloride induced hepatic damage in male Albino Wister rats. The activity of these extracts (500-mg/kg b. w for 7 days) was compared with the standard drug silymarin (Silybon-70, 10 mg/kg-b.w). The petroleum ether, chloroform and methanolic extracts have shown significant hepatoprotective activity by reducing the elevated levels of serum enzymes such as serum glutamate oxaloacetate transaminase (SGOT) by 17.69, 67.0 and 30.80%, serum glutamate pyruvate transaminase (SGPT) by 19.0, 22.30 and 39.29%, alkaline phosphatase (ALP) by 17.32, 28.99, 35.38% and increased total protein (TP) by 22.49, 31.84, and 34.29% respectively indicating that the methanol extract was the most active among the three extracts as compared to standard drug silymarin, which decreased SGOT by 53.04, SGPT by 55.96, ALKP by 35.87 and increased TP levels by 59.24% against CCl 4 intoxicated rats in comparison to normal control. These biochemical observations were also supplemented by histopathological examinations of the liver sections. The results showed that the methanolic extract was the most active among all the extracts.