IN VITRO ANTIOXIDANT AND FREE RADICAL SCAVENGING POTENTIAL OF METHANOLIC EXTRACTS OF UVARIA CHAMAE LEAVES AND ROOTS
Objective: This study investigated the in vitro antioxidant and free radical potentials of methanol extracts of Uvaria chamae leaves and roots.
Methods: Fresh Uvaria chamae leaves and roots were air dried, pulverized and extracted using methanol. Phytochemical, total phenolic, flavonoids, antioxidant and tannin contents, DPPH, hydroxyl, and superoxide radical scavenging properties of the extracts were determined using standard methods.
Results: In vitro antioxidant potentials revealed that methanol extract of Uvaria chamae leaves contains vitamin A (4871±79.21 I. U) and vitamin C (1.72±0.02%) while the root extract contains vitamin A (673.28±0.00I. U) and vitamin C (1.66±0.01%). Both extracts had equal contents of vitamin E (8.83±0.04 mg/100g). The leaf extract scavenged 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) in a concentration dependent manner with the correlation coefficient (R2) of 0.839 and effective concentration (EC50) of 31.19 µg/ml, while the root extract scavenged DPPH with R2 of0.778 and EC50 of 14.00 µg/ml. The leaf and root extracts scavenged superoxide radical and hydroxyl radical with EC50 of 5.93 µg/ml and 719.45 µg/ml; 107.89 µg/ml and 912.01 µg/ml respectively compared to the EC50 of ascorbic standard (30.27 µg/ml) and EC50 of vitamin E standard (106.66µg/ml) respectively. The leaf extract showed significantly higher (p<0.05) anti radical power (ARP) of superoxide (0.17) compared to the root extract (0.0014) and the root extract showed significantly higher (p<0.05) ARP of DPPH (0.071) compared to the leaf extract (0.032).
Conclusion: The leaves and roots of Uvaria chamae are rich in natural antioxidants that can be exploited in the treatment of diseases related to oxidative stress.
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