Methyl parathion (MP) (C8H10NO5PS) is an organophosphate insecticide that has been used in agriculture
for several years. The people who are at the greatest risk of being exposed to MP are farm workers,
chemical sprayers, and people who work in factories handling MP. The main route of human exposure
is inhalation, but dermal contact and inadvertent ingestion can also be substantial. The present work
was planned to study the toxic effects of MP on some antioxidative markers as well as the liver and kidney.
The influence of silymarin (Sily) on MP induced toxicity has not been studied, So, the possible protective
effect of (Sily) had been also evaluated. The study was conducted on one hundred male albino rats
divided into five main equal groups and each of them were subdivided equally into two subgroups.
Group-I (A&B), control group: received no treatment, group-II (A&B): vehicle group (1 ml/kg/day of
corn oil, P.O.), group-III (A&B): Sily group (100 mg/kg/day, P.O.), group-IV (A&B): MP group (0.28
mg/kg/day, P.O.), group-V (A&B): Sily+MP. At the end of 4th and 8th weeks, blood samples, renal and
hepatic tissues were collected for biochemical and histological examinations. Biomarkers selected for oxidative
stress were antioxidant defense system superoxide dismutase (SOD) and reduced glutathione
(GSH) as well as malondialdehyde (MDA). In addition, liver profile (AST, ALT, and ALP) and kidney
profile (Blood urea and creatinine) were assessed. Also, histological examination of liver and kidney was
done. The results showed that administration of MP resulted in oxidative stress as evidenced by significant
decrease in SOD activity and GSH levels accompanied with significant increase in MDA levels. At
the same time, there was hepato-nephrotoxicity as manifested by significant increase in liver and kidney
function tests when compared with control rats. Comparing with MP-treated rats, Sily supplementation to
the rats, 30 minutes before MP administration, resulted in a significant increase in SOD activity and GSH
levels. However, MDA levels, liver and kidney enzymes showed significant decrease. The histopathological
results confirmed the biochemical results. In conclusion, the obtained biochemical and histological
results of this study revealed hepatic and renal toxic effects induced by MP in a time-dependent manner.
Sily supplementation resulted in a remarkable protective effect against MP-induced oxidative stress and
hepato-renal toxicity. |
