Rotenone induces hepatotoxicity in rats by activating the mitochondrial pathway of apoptosis

Abstract As a pesticide extracted from plants, rotenone is widely used to control plant pests. In order to explore the safety of rotenone in the environment, we took 60 healthy male SD rats and randomly divided them into rotenone low-dose group, rotenone medium-dose group, rotenone high-dose group, dimethyl sulfoxide group (DMSO), and control group. After 28 days of oral administration, the rat liver tissue ultrastructure, liver function, oxidative stress indexs, mitochondrial function, and apoptosis-related factors were tested to evaluate the hepatotoxicity and toxicological mechanism of rotenone. The results showed that rotenone significantly increased the hepatic index of rats and the activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum. Rotenone can reduce the number of endoplasmic reticulum of hepatocyte, concentrate chromatin and make the hepatocyte nuclears irregular. Rotenone weakened the ATP synthesis ability in mitochondria, decreased the activity of ATP enzyme in mitochondria, and increased the mitochondrial membrane potential in the high-dose group. And it induced oxidative stress damage to the mitochondria of rat liver cells. Rotenone can upregulate the expression of pro-apoptotic factors and downregulate the expression of anti-apoptotic factors. These results indicate that oral rotenone in rats induced hepatotoxicity in a dose-dependent manner. The mechanism of rotenone poisoning is that oxidative stress damages organelles of hepatocyte such as mitochondria and endoplasmic reticulum, resulting in their function being weakened or lost, leading to hepatocyte apoptosis.