Determination of Antioxidant Activities of Moringa oleifera Leaves from Selected Countries

Abstract

Moringa oleifera is a native plant from Asia, grown in the tropics.  The leaves, bark, flowers, fruits, seeds, and roots are rich sources of phytochemicals and antioxidants; hence, they have been extensively utilized for medicinal purposes. This study aimed to determine the Antioxidant Activities of methanolic and ethanolic extracts of five varieties of Moringa leaves from Nigeria, Ghana, Haiti, India, and USA.  The leaves were extracted using aqueous methanol and ethanol. 2, 2, -diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, Ferric Reducing Antioxidant Power (FRAP), and Trolox equivalent antioxidant capacity (TEAC) were then determined.  Results indicated there were significant differences were recorded in DPPH, FRAP, and TEAC respectively. A significant difference in DPPH radical scavenging activities in the leaves from Haiti (94.83µmol TE g-1) and Ghana (86.69µmol TE g-1), Haiti (94.83µmol TE g-1) and Nigeria (84.94µmol TE g-1) respectively. Highest activity was observed in the ethanolic extract from the USA (123.48 µmol TE g⁻¹), while the lowest was in the methanolic extract from Nigeria (84.94 µmol TE g⁻¹).  A similar result was also recorded for TEAC with ethanolic extracts from Ghana (61.59µmol TE g-1) significantly different from Nigeria (63.36µmol TE g-1), India (63.34µmol TE g-1), Haiti (62.42µmol TE g-1) and USA (62.36µmol TE g-1). FRAP methanolic extracts from Nigeria (232.96mg GAE g-1), USA (214.24mg GAE g-1) and India (201.81mg GAE g-1) were significantly different, while extracts from Haiti (222.16mg GAE g-1) and Ghana (221.35mg GAE g-1), USA (214.24mg GAE g-1) and Ghana (221.35mg GAE g-1) were in range.