Phytochemical Analyses, Antioxidant and Anticancer Activities of Ethanolic Leaf Extracts of Moringa oleifera Lam. Varieties

Moringa oleifera Lam. (Moringaceae) is revered as s 'miracle tree' due to its remarkable nutritional, medicinal and industrial uses. In our study, a comparative analysis of the nutritional parameters (antioxidant activity, sugar content-TSS, total soluble proteins-TSP and mineral contents), phytochemicals (HPLC analysis of four anticancer compounds), and cytotoxicity of M. oleifera leaf extracts (MLEs) of five selected varieties (conventional, PKM-1, PKM-2, ODC, and Jaffna), was performed. Jaffna variety possessed the highest antioxidant activity (FRAP) followed by other four varieties. The trend observed was: Jaffna (9.47 mu g/mL, 18.48 mu g/mL, 29.39 mu g/mL, and 35.37 mu g/mL) > PKM-1 (4.82 mu g/mL, 7.63 mu g/mL, 22.33 mu g/mL, and 27.71 mu g/mL) > PKM-2 (2.10 mu g/mL, 7.04 mu g/mL, 13.18 mu g/mL, and 21.78 mu g/mL) > ODC (0.17 mu g/mL, 2.10 mu g/mL, 4.41 mu g/mL and 13.94 mu g/mL) > Conventional (0.05 mu g/mL, 1.08 mu g/mL, 2.86 mu g/mL, and 5.40 mu g/mL), total soluble proteins (TSP) [0.69 & PLUSMN; 0.01 and 0.94 & PLUSMN; 0.01 mu g/mL (young and mature stage, respectively)], sugar content (TSS) [0.39 & PLUSMN; 0.01 and 0.51 & PLUSMN; 0.01 mu g/mL (young and mature stage, respectively)], chlorophyll content [1.07 & PLUSMN; 0.01 (plantlet stage), 1.36 & PLUSMN; 0.003 (vegetative-stage), 0.82 & PLUSMN; 0.004 (reproductive stage) mg/g], followed by the other four varieties. The trend observed for cytotoxic activities of ethanolic MLEs on HepG2 cell line, based on the IC50 values, was conventional (1.22 mg/mL) > ODC (0.90 mg/mL) > PKM-2 (0.65 mg/mL) > PKM-1 (0.35 mg/mL) > Jaffna (0.15 mg/mL). The results of HPLC quantification of anticancer compounds [beta-sitosterol (0.244%), quercetin (0.216%), kaempferol (0.013%), and moringin (0.063%)] was also in consonance with that of MTT assay. In summary, the trend observed in all the parameters tested was Jaffna > PKM-1 > PKM-2 > ODC > conventional. Thus, Jaffna variety has a better potential to combat malnutrition and cancer and must be recommended for commercial plantations.