Protective and curative effect of silymarin against chlorpyrifos-induced immunotoxicity in rats

Abstract

Chlorpyrifos (CPF) is a widely used organophosphorus insecticide throughout the world inagriculture and anti-termites around homes. Silymarin is a naturally occurring substance and hasantioxidant effects. For decades, it has been used clinically in Europe for the treatment ofalcoholic liver disease and as anti-hepatotoxic agent. Therefore, the present study aimed toassess the protective and curative effect of silymarin in attenuating the CPF-inducedimmunotoxicity in rats, by measuring the level of immunoglobulin G (IgG), lymphocyteviability, neutrophil phagocytic function assay, total white blood cells count (WBC) and relativedifferential white blood cells count, as well as nitric oxide (NO) level and catalase activity. Thetreatment with CPF decreased lymphocyte viability, neutrophil phagocytic index, total whiteblood cells count, relative lymphocyte count, IgG concentration and catalase activity. On theother hand, a high level of NO was detected upon animal treatment with CPF. Interestingly,pre- and post-treatment with silymarin to CPF-treated group improved the lymphocyte viability,total white blood cells count, relative lymphocyte count, catalase activity and the NO level. Preandpost-treatment with silymarin recovered phagocytic activity of neutrophils and restored IgGlevel. In conclusion, silymarin has both protective and curative effects against CPF-inducedimmunotoxicity may be through its anti-oxidant effects.