Objective: This paper reports a comparative study based on the chemical composition, antioxidant and therapeutic effect of two Egyptian cultivars of Solanum tuberosum; Baraka (STB) and Alpha (STA) on hepatic functions and oxidative stress in alloxan (ALX)-treated rats.Methods: The potential of cultivars as a source of natural antioxidants were explored using five in vitro assays, and the results were compared with butylated hydroxyl toluene and Trolox. The modulator role of cultivars was assessed by determining its effect on oxidative stress measured by lipid peroxide (LPO) levels, serum aminotransferases and on antioxidative enzymatic activities of glutathione transferases, malondialdehyde, nitric oxide, catalase, superoxide dismutase, and glutathione peroxidase. In addition, histological examinations of liver, kidney, pancreas and spleen were carried out to confirm the biochemical changes of the diabetic group of rats non-treated and treated with STB, STA and glibenclamide as standard drug.Results: Our findings demonstrated variations in antioxidant activities of each cultivar. An increase in LPO, aminotransferases levels was observed in the ALX-induced diabetic rats. Administration of each cultivar for four w caused a significant reduction in LPO, serum aminotransferases levels in the ALX-induced diabetic rats. Furthermore, a significant improvement in the activities of all the investigated antioxidant enzymes was marked. In addition, the total content of phenolics, flavonoids, anthocyanins, tannins, and alkaloids were varied in each cultivar.Conclusion: STB evidenced remarkable bioactivity compared to that exhibited by STA. Moreover, three known compounds, previously not isolated from Solanum genus, were obtained from the methylene chloride fraction of STB.Â
