Abstract

Lead (Pb) is widespread toxic metals found in the environment and potential danger to human health. This study investigated the possible protective roles of propolis against Pb-induced neurotoxicity. Forty male adult (Swiss albino rats) rats were divided into four groups: Group-I {Control: 1 ml distilled water intraperitoneal (i.p.)}; group-II, received propolis at a dose of 50 mg/kg/day daily orally (p.o.); group-III, (Pb treatment: 1 mg/kg i.p.) and group-IV (propolis and Pb treatment: 50 mg propolis/kg p.o. and Pb (1 mg/kg i.p.) daily for four weeks. Activity level of acetylcholinesterase (AChE activity), lipid peroxidation (MDA), protein carbonyl content (PCC), sulphhydryl proteins (P-SH), vitamin C, vitamin E, NADH-cytochrome C reductase, succinate dehydrogenase (SDH) and cytochrome oxidase activities were examined in different groups. Results showed that co-administration of propolis with Pb inhibited Pb-induced neurological toxicity as indicated by normalization of AChE activity, inhibition of brain MDA and PCC formation. In addition, propolis protects the mitochondrial NADH-cytochrome C reductase, SDH and cytochrome C activities from Pb-induced amelioration. Furthermore, propolis increased brain vitamin C, vitamin E and P-SH levels in rat's brain both in group treated by propolis alone and group treated by propolis and Pb. It can be concluded that propolis has beneficial effects and could be able to antagonize Pb-induced neurotoxicity.

Key words: Propolis, lead, neurotoxicity, oxidative stress.