Effect of paraquat intoxication and ambroxol treatment on hydrogen peroxide production and lipid peroxidation in selected organs of rat.

Paraquat (Pq) is a herbicide which is very toxic to all animals and to man. It generates free radicals and leads to acute or chronic lung injury and usually to death. So far, the role of lipid peroxidation of cell membranes in the mechanism of its toxicity has not been proved satisfactorily and therefore in the present study we examined the concentration of hydrogen peroxide (H2O2) and various lipid peroxidation products (LPP) such as conjugated dienes (CD), lipid hydroperoxides (LH), malonyldialdehyde (MDA) and Schiff bases in selected organs of the rat given a single intraperitoneal dose 35 mg kg-1 Pq. We also evaluated the influence of a mucolytic and probably antioxidant drug, ambroxol, on Pq-induced changes in the concentration of H2O2 and LPP. Paraquat increased the hepatic concentration of H2O2, CD, LH and MDA by approximately fourfold. Though the dose of Pq was nearly twice the LD50 dose, we did not notice any changes in the concentration of these substances in the critical organ, lung or heart and kidney. Ambroxol alleviated the increase of H2O2 in the liver but did not reduce the concentration of LPP. Moreover, the drug administered alone induced lipid peroxidation in the liver. Our results indicate that Pq dose not induce H2O2 production and lipid peroxidation in the lung but it increases the concentration of H2O2 and LPP in the liver. Ambroxol inhibits the Pq-induced increase in the concentration of H2O2 in the liver without protecting it against lipid peroxidation. Moreover, the drug alone may act as a pro-oxidant.