The protective effect of aqueous propolis extract on isolated rat hepatocytes against carbon tetrachloride toxicity.

The protective effect of honeybee aqueous propolis extract (APE) against the hepatotoxicity of carbon tetrachloride was investigated using isolated liver-cell suspensions as the experimental model. Various concentrations of the extract were preincubated with the hepatocyte suspensions for 30 min before being subjected to the hepatotoxin for a further 30 min. The hepatocyte toxicity was assessed using three parameters, namely, the release of lactate dehydrogenase, the formation of lipid peroxides and the depletion of intracellular reduced glutathione. It was found that a dose-related protection against the induced cell injury was conferred by APE as evidenced by its inhibitory influence on the changes induced by CCl4 on the measured parameters. The hepatocyte protective effect of APE is probably a result of its antioxidant and free-radical-scavenging properties which in turn help to maintain the intracellular level of reduced glutathione.