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Antioxidants are essential compounds to maintain proper health conditions in human
body by diminishing the oxidative stress. Synthetic antioxidants are found to be unsafe
for human health. Hence, there is a growing interest on searching for natural resources
with potent antioxidant activity. The antioxidant activity o f the fractions o f total ethanol
extract o f F. indica bark was determined by in vitro antioxidant assays. Previous studies
have evaluated the antioxidant activity o f methanolic and aqueous extracts o f F. indica
leaves. This study was aimed on investigating the antioxidant activity o f petroleum ether,
ethyl acetate, ethanol and total ethanol extract o f F. indica bark using different
antioxidant assays and fractionation o f total ethanol extract. Total ethanolic extract of F.
indica bark was obtained by extraction o f the air-dried, powdered stem bark with ethanol
using cold extraction technique. Ethanol extract was purified further by fraction using
Dry Column Flash Chromatography (DCFC). The final 10 fractions were subjected to invitro 2, 2-diphenyl-2-picrylhydrazyl (DPPH) assay to determine the percent radical
scavenging activity. The total ethanol crude extract exhibited a good percent radical
scavenging activity o f 93.4%. Among fractions, F6 and F10 showed the highest
scavenging effect o f 93.4% and 92.5% respectively. The fractions F9, F4 and F8 showed
moderate free radical scavenging activity having 85.3%, 65.8%, and 64.9% respectively.
FI and F2 fractions demonstrated the lowest scavenging effect o f 6.4% and 5.5%.
Sequential petroleum ether, sequential ethyl acetate, sequential ethanol and total ethanol
extracts showed 7.8%, 37%, 62% and 93% percent radical scavenging activity,
respectively. Ferric Reducing Antioxidant Power (FRAP) values o f sequential ethyl
acetate, sequential ethanol and total ethanol extracts were 354.51±3.69, 393.31±6.07 and
463.10±2.3 mg TE/g extract respectively. Oxygen Radical Absorbance Capacity (ORAC)
values o f sequential ethyl acetate, sequential ethanol and total ethanol extracts were
625.27 ±0.1, 652 ± 0.12, 515 ± 0.12 mg TE/g extract, respectively. Present investigation
suggests that total ethanol extract fractions and sequential extracts except sequential
petroleum ether extract exhibited high antioxidant activity. Furthermore, polar fractions
and extracts showed more potency towards antioxidant activity than non-polar fractions
and extracts. F. indica stem bark may be used as a potential source o f antioxidant
ingredient in nutraceutical products.
