Tea catechins protect against lead-induced ROS formation, mitochondrial dysfunction, and calcium dysregulation in PC12 cells.

Abstract

Recent studies have shown that lead causes oxidative stress by inducing the generation of reactive oxygen species (ROS) and reducing the antioxidant defense system of cells, which suggests that antioxidants may play an important role in the treatment of lead poisoning. The present study was designed to elucidate whether tea catechins had any protective effects on altered oxidative stress parameter in PC12 cells exposed to lead. The experimental results showed that lead decreased PC12 cell viability and induced a rapid elevation of [Ca(2+)](i), which was followed by an accumulation of ROS and a decrease of mitochondrial membrane potential (MMP). Treatment by tea catechins significantly increased cell viability, decreased intracellular Ca(2+) levels and ROS formation, and improved MMP in PC12 cells exposed to lead. The galloylated catechins showed a greater effect on ROS formation and mitochondrial dysfunction than that of nongalloylated catechins, which was similar to the result of their scavenging ability on free radical. In view of the time course of ROS formation and mitochondrial dysfunction and their correlation, our results also suggested that the beneficial effects of tea catechins on MMP are related, at least in part, to its ability to scavenge ROS in PC12 cells exposed to 100 microM Pb(2+). The present results suggest that tea catechins supplementation may play a role for modulating oxidative stress in PC12 cells exposed to lead.

• Authors: Liuji Chen, Xianqiang Yang, Hongli Jiao, Baolu Zhao
• Journal: Chemical research in toxicology (Chem Res Toxicol) Vol. 16 Issue 9 Pg. 1155-61 (Sep 2003) ISSN: 0893-228X [Print] United States
• PMID: 12971804 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Reactive Oxygen Species
• Tea
• gallocatechin gallate
• Lead
• Catechin
• epicatechin gallate
• epigallocatechin gallate
• Calcium

Topics

• Animals
• Calcium (metabolism)
• Catechin (analogs & derivatives, chemistry, pharmacology, physiology)
• Cell Death (drug effects, physiology)
• Cell Survival (drug effects, physiology)
• Dose-Response Relationship, Drug
• Lead (adverse effects, antagonists & inhibitors)
• Membrane Potentials (drug effects)
• Mitochondria (drug effects, pathology)
• Oxidative Stress (drug effects)
• PC12 Cells
• Rats
• Reactive Oxygen Species (chemistry, metabolism)
• Tea (chemistry)