Cardioprotective Potential of <i>Calotropis procera</i> (Giant Milkweed) Leaf Extract on Sodium Nitrite-Induced Toxicity in Wistar Rats

Sodium nitrite (NaNO2) is frequently used as a preservative for curing meats like hot dogs, bacon, and ham. However, when ingested in high quantity, it gets to toxic level and induces cardiovascular toxicity and other diseases. The aim of this study is to investigate the cardioprotective and antioxidant potential of ethanolic extracts of Calotropis procera (C. procera) leave(s) on sodium nitrite-induced toxicity and oxidative stress in male Wistar rats. Thirty-two adult male rats were randomly and equally divided into four groups (n=8) and handled daily for 28 days as follows: Group 1; received distilled water only, Group 2; 1 g/L of NaNO2, Group 3 1 g/L NaNO2 + 250 mg/kg bw of C. procera leaf extract and Group 4; 250 mg/kg bw C. procera leaf extract. Phytochemical analysis was done. Blood samples were collected from the animals by cardiac puncture at the end of the treatment and serum samples were prepared for cardiac function assay. Heart tissues were excised for histopathological study and estimation of antioxidant capacity. Weight changes were monitored before and at the end of treatment. Results showed the presence of phytochemicals such as alkaloids, flavonoids, tannins, total phenols and saponins. Significant growth changes were observed in groups 1, 2 & 3 over the 28 days compared to the control while group 4 animals had a weight loss. Treatment with C. procera reduced significantly the serum induced-increase in creatinine kinase and lactate dehydrogenase. The activity of MDA was reduced by the extract while GSH, GST, CAT, GPX and CAT were in the heart homogenate were significantly increased by the extract. The extract caused no lesion to the architecture of the heart. These results showed that C. procera leaf extract ameliorated toxicity in rat hearts and significantly increased antioxidant capacity.