The liver plays a central role in metabolism due to its interposition between the digestive tract and the general circulation of the organism. It is also the main organ involved in biotransformation of exogenous substances (xenobiotics), with ability to convert hydrophobic compounds in water-soluble, more easily eliminated by the body. Gossypol is a toxic phenolic substance present in cotton seed (Gossypium sp.). Aiming to study the mechanisms involved in the hepatotoxicity of gossypol we evaluate its effects on the antioxidant system of rat liver performing an experiment that investigated the oxidative stress and the histopathological alterations. In this study, we used Wistar rats, divided into two groups, one that received canola oil (vehicle, Control group) and another that received gossypol at a dose of 40mg/kg body weight of the animal for 15 days (Treated group). The treatment with gossypol caused alterations in the activity of seric enzymes that indicate hepatic injury and a significant oxidative stress characterized by a decrease of reduced glutathione (GSH) levels and a consequent increase in oxidized glutathione (GSSG), including further damage to the plasma membrane and organelles showed by lipid peroxidation. The result of histopathological evaluation showed degeneration of the hepatocytes.

The hypercaloric diet is an important inducer of dyslipidemias and, in turn, causes damage to health, especially to the liver.This work was developed with the objective of testing bixin, a carotenoid present in the seeds of annatto (Bixa orellanaL.), verifying its side effects on lipid and hepatic metabolism in rats. Fifteen animals were randomly divided into control (C), hypercaloric (H) and hypercaloric groups with bixin (H+B) with five animals each, receiving feed ad libtumduring the period of 25 days.The diet with bixin promoted weight maintenance, decreased ALT levels, decreased triglyceride levels and increased HDL-c. Theliver histopathology showed a decrease in fat degeneration, inflammatory infiltrate and cell injury.