Comparative Phytochemical Screening, In Vivo Antioxidant and Nephroprotective Effects of Extracts of Cassava Leaves on Paracetamol-intoxicated Rats

The phytochemical screening, antioxidant, and nephroprotective effects of methanol and acetone extracts of cassava (Manihot esculenta Crantz) leaves were comparatively investigated using standard procedures. Fifty-four male Wistar rats (albino) were divided into nine groups of six rats each. Group 1 = negative control (normal untreated rats + normal saline); group 2 = positive control (rats + 2g/kg bw acetaminophen + normal saline), groups 3, 4, and 5 = 200mg/kg bw, 100mg/kg bw, and 50mg/kg bw of methanol extract, respectively, + 2 g/kg bw acetaminophen; groups 6, 7, and 8 = 200mg/kg, 100mg/kg bw, and 50mg/ kg bw of acetone extract, respectively, + 2 g/kg bw acetaminophen; and group 9 = 100mg/kg silymarin + 2 g/kg bw acetaminophen. The phytochemical screening of the methanol and acetone leaves extracts showed the presence of flavonoids, alkaloids, saponins, anthocyanins, tannins, and triterpene, whereas, cardiac glycoside, steroids, and anthraquinone were absent in both extracts. Acetaminophen administration significantly elevated the levels of serum urea, creatinine, sodium, and potassium with a corresponding decrease in the levels of total protein, albumin, and calcium in the group 2 rats compared with that in the group 1 rats. Similarly, the levels of superoxide dismutase, catalase, glutathione peroxidase, glutathione, and glutathione S-transferase were significantly less in the acetaminophen-intoxicated group than that in the negative control group. However, pretreatment with either extracts, dose dependently prevented the acetaminophen-induced derangement of the aforementioned parameters. The extracts showed antioxidant activity similar to the reference drug (silymarin). Comparatively, the methanol extract gave higher in vivo antioxidant and nephroprotective effects than the acetone extract. The results suggest the extracts of cassava leaves have high nephroprotective potential and may be based on their phytoconstituents and antioxidant activity.