Toxic effects of subchronic exposure to malathion on liver and kidney: a possible preventive role of L-ascorbic acid and soyabean

ABSTRACT

The study comprised 150 male albino rats divided into 5 groups [n=30] according to diet regimen used control group [normal diet], malathion group [1 mg malathion dissolved in 100ml of water was added to the diet], vitamin C group [L-ascorbic acid in a dose of 200mg/kg]. Soya group [Soya bean powder in a dose of 40 gm/kg], and combination group. Ten rats were sacrificed at 2, 4, and 6 weeks after the start of diet regimen. Blood samples were collected via cardiac puncture, then animals were sacrificed and liver and kidneys were removed for histopathologic examination. Blood samples were examined for serum levels of alanine aminotransferase [ALT], alkaline phosphatase [alk. Ph], g-glutamyl transferase [GGT], creatinine and lipid peroxides [LP]. There was a significant [P<0.05] increase of serum ALT, alk. Ph, and GGT in group II compared to the other groups, at 2, 4 and 6-wks, with a significant [P<0.05] increase at 4 and 6 weeks compared to levels detected at 2-wks. Group V showed the least affection of liver function tests despite being significantly [P<0.05] increased compared to control group. L-ascorbic acid and Soya bean separately, induced significant [P<0.05] decrease in enzyme levels compared to group II, but significantly [P<0.05] increased compared to group I. Serum creatinine showed a significant [P<0.05] increase in group II compared to the other groups. However, the addition of either or both L-ascorbic acid and Soya bean to malathion contaminated diet significantly [P<0.05] attenuated the deleterious effects of malathion on serum creatinine. There was significant [P<0.05] increase of serum LP in group II compared to the other groups at 2, 4 and 6 weeks, with a significant increase [P<0.05] of serum LP at 4- and 6-wks compared to levels detected at 2-wks. However, there was a non-significant difference between groups III-V, despite the significantly [P<0.05] increased levels in groups III and IV compared to the control levels. In liver specimens, increased lymphocytic infiltration and mild cellular vaculation were found in 4-wks specimens. In 6-wks specimens, there was abundant lymphocytic infiltration, and appearance of scattered masses of necrotic areas. Kidney specimens showed mild lymphocytic infiltration and hemorrhagic spots, and intense lymphocytic infiltration, intense hemorrhage and areas of necrosis in 4 and 6 weeks specimens, respectively. Changes were more evident in group II specimens, fiowever, group V rats showed least changes that appeared only in 6-wks specimens. We can conclude that the subchronic exposure to malathion induces toxic effects on liver and kidney via initiation and maintenance of lipid peroxidation, an event that can partly prevented by coadministration of ascorbic acid and Soya bean