Analytical comparison of the phytochemical composition and antioxdant actvity of methanol extracts derived from <I>Alchornia cordifolia</I> and <I>Corchorus olitorius</I>

Abstract

Oxidative stress is an underlying pathological state in cancer, cardiovascular disease and diabetes. Medicinal plants are considered to be potential remedies for attenuating oxidative stress in these pathologies because they possess antioxidants. Thus, the quantity and activity of antioxidants in Alchornia cordifolia and Corchorus olitorius methanol leave extracts were evaluated in this study using phytochemical screening, 1,1 diphenyl-2-picrylhydrazyl (DPPH)free radical-scavenging ability, ferric reducing antioxidant power (FRAP) and reducing power assays. Qualitative phytochemical analysis showed that the two plant extracts had alkaloids, saponins, reducing sugar, terpenoids, flavonoids and tannins. While the quantitative phytochemical test revealed a greater presence of total flavonoids and proanthocyanidins (p<0.05) in Corchorus olitorius methanol extract compared to A. cordifolia methanol extract. Contrastingly, the quantities of total tannins and phenols were higher in Alchornia cordifolia methanol extract than in Corhorus olitorius extract. The capacity of Alchornia cordifolia to mop up DPPH (IC₅₀= 0.01μg/mL) was greater than that of ascorbic acid (IC₅₀= 0.055μg/mL) and C. olitorius extract (IC₅₀= 33.10μg/mL) respectively. Ferric reducing potential of C. olitorius (479.80μM Fe(II)/g and A. cordifolia methanol extracts(510 μM Fe(II)/g) were significantly lower (p<0.05) than what was obtained for ascorbic acid (1005μM Fe(II)/g). A. cordifolia methanol extract demonstrated higher reducing power than C. olitorius methanol extract at identical concentrations. Our findings indicated that Alchornia cordifolia could be used as a rich source of antioxidants to alleviate oxidative stress underlying many chronic diseases.

Keywords: Alchornia cordifolia, Corchorus olitorius, phytochemicals, antioxidants