Background: Vernoniaamygdalina and Ocimumgratissimumare widely used plants in the tropics. The leaves of
these plants are popularly acclaimed to have medicinal values, with scarce information on the effect of graded extracts
in mediating oxidative stress. The interest on these leaves derives from the need to have an insight to the possible effect
of thesegraded leaves extracts may have on oxidative stress. Objectives: The objective of the study was to examine
the effect of graded extracts of Vernoniaamygdalina and Ocimumgratissimum leaves specifically on free radical inhibition,
reducing power and lipid peroxidation in rat liver and kidneys. Methods: The leave samples were collected and air
dried, homogenized and sieved to obtain particle sizes of ≤ 0.250mm. Aqueous and methanolic extracts of samples
were obtained and used to assay for total alkaloid and phenolic contents, free radical scavenging activity, reducing
power and the extent of lipid peroxidationin liver and kidneys were determined, using standard analytical assays. Results:
Phenolic contents of both leave extracts were higher in aqueous medium vernoniaamygdalina (0.85 ±
0.07mgGAE/g) and Ocimumgratissimum (1.59 ± 0.13mgGAE/g). The alkaloid contents of the leaves were higher in
methanolic extracts, with Ocimumgratissimum highest (0.96 ± 0.04μg/g) and vernoniaamygdalina (0.38 ± 0.01μg/g).
The reducing power of these leaves increased with increasing extract concentrations. Ocimumgratissimum had the highest
reducing power in both methanolic (3.00 O.D) and aqueous (2.82 O.D) medium in comparison with respective
butylatedhydroxytoluene (BHT) (2.49 O.D) and ascorbic acid (2.16 O.D) controls. The ability to scavenge free radicals
increased with increasing extract concentrations in both leaves with highest percentages in aqueous extracts.
Ocimumgratissimum(95.90%) and vernoniaamygdalina(98.80%) compared to control (100%).The leave extracts of
both plants significantly (p
Key words: Scent leaf, Bitter leaf, iron, free radicals
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