Antioxidant and cardioprotective effect of Leptadenia reticulata against adriamycin-induced myocardial oxidative damage in rat experiments

The present study was intended to investigate the in vitro antioxidant effect and plausible cardioprotective effect of a methanolic extract of Leptadenia reticulata (LRM) in experimental rats using biochemical and histopathological approaches. LRM was evaluated for in vitro antioxidant activity using DPPH (1,1-diphenyl-2-picrylhydrazyl) radical, nitric oxide and hydroxyl radical scavenging activity. LRM exhibited prominent antioxidant activity by scavenging or inhibiting the DPPH, nitric oxide and hydroxyl radical. Further, LRM was investigated for its possible protective effect against adriamycin-induced (ADR) cardiotoxicity in rats. Wistar rats were administered with LRM at doses of 250mg/kg and 500mg/kg for 28 days followed by intra peritoneal injection of adriamycin (10mg/kg). Oxidative stress in the myocardium of ADR treated rats was evidenced by decreased levels of the marker the enzymes viz. alanine transaminase, aspartate transaminase, lactate dehydrogenase and creatine kinase in heart homogenate with concomitant increase in these enzyme levels in serum. The basal levels of myocardial antioxidant enzymes like superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase were also reduced by ADR. Myocardial reduced glutathione was found to be decreased with consequent increase in lipid peroxidation due to ADR administration. Pretreatment with LRM significantly inhibited the alterations in the aforementioned biochemical parameters. One-way ANOVA followed by Bonferroni test was applied to test statistical significance. The histopathology revealed that LRM pretreatment inhibited adriamycin-induced degenerative changes and cellular infiltrations in heart in dose dependent manner. The results indicated that ADR treatment markedly impaired cardiac function and LRM prevented this toxicity, which might be due to the virtue of its antioxidant activity.

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