The protective role of Scoparia dulcis on tissue antioxidant defense system of rats exposed to cadmium

The possible antioxidant property of aqueous extract of Scoparia dulcis was tested in rats exposed to cadmium. Different groups of animals were treated with CdCl2 alone or in combination with graded levels of S. dulcis (i.e. 250, 500 and 1000 mg/kg body wt, respectively). Cadmium, a known prooxidant was administered subcutaneously (3 mg /kg body wt), once every week, for two weeks. The required dose of aqueous extract of S. dulcis was administered daily for 2 weeks by gavage. The results show that relative to controls, cadmium significantly (P<0.05) reduced superoxide dismutase activity while significantly (P<0.05) increasing catalase activity and malondialdehyde levels in the liver and kidney. However, no significant effect was observed in the antioxidant enzyme activities and MDA levels in the heart. The dose of 1000 mg S. dulcis/kg body wt, like cadmium when administered alone, exhibited a prooxidant effect but when coadministered with cadmium, the high dose of S. dulcis effectively restored the antioxidant enzyme activities in the kidney and liver to levels that are not statistically different from the control. These observations show that aqueous extract of S. dulcis possesses significant antioxidant activity, sufficient to mitigate against free radical induced oxidative stress in experimental cadmium intoxication in the rat.