Mohammad Nurul Amin, Syed Masudur Rahman Dewan, Wahiduzzaman Noor and A. F. M. Shahid-Ud-Daula
The present study was conducted to evaluate the possible chemical groups present, total phenolic content, and antioxidant activity of ethanolic extract of leaves of Ocimum sanctum. In the study, presence of tannin and flavonoid were found significant in the crude extract. For investigating the antioxidant activity, three complementary test systems, namely DPPH free radical scavenging, reducing power assay and ferrous ion chelating ability were conducted. In DPPH free radical scavenging test, IC50 value for the crude extract was found fairly significant (7.23±0.05 μg/ml) while compared to that of the reference standards ascorbic acid and BHA (2.12±0.02 & 4.87±0.05 μg/ml respectively). In reducing power assay, the maximum absorbance for the extract was found 2.155 ±0.018 at 100 μg/ml while compared to 2.811 ± 0.013μg/ml and 2.031± 0.019 μg/ml for standard ascorbic acid and BHA respectively. The IC50 value of the extract as percentage of Fe++ ion chelating ability was determined as 19.05±0.08 μg/ml where EDTA showed 8.87±0.035 μg/ml. The total phenolic amount was also calculated as quite high in the extract 279.05±0.73 mg/g of gallic acid equivalent). Therefore, the obtained results tend to suggest potent antioxidant activities of the crude ethanolic extract of the leaves of O. sanctum and justify its folkloric use.
