Abstract:
In the present investigation, phenolic content and antioxidant activities of methanolic extracts of Nigella sativa seeds relative to Ethiopian and Indian black cumin were examined. Ferric thiocyanate test was carried out to find the reducing power of both types of Nigella sativa seeds. This test was utilized in explaining antioxidant activity of methanolic extracts of seeds. The phenolic composition of the methanolic extracts was estimated by Folin-Ciocalteu spectrophotometric method. Significantly higher amount of total phenolic content was exhibited by Ethiopian black cumin seeds compared to Indian type with a mean value of 437.00μg Gallic acid equivalents per g of powdered seed and the lowest mean value was 89.53μg Gallic acid equivalents per g of powdered seed. Similarly, high DPPH radical scavenging activity, with IC50 value of 7.22± 0.27 and 8.30± 1.34mg of Gallic acid equivalents per mL respective to Ethiopian and Indian Nigella seeds were observed. In addition, ABTS radical scavenging assay showed IC50 value of 9.29± 0.31 and 6.82 ± 1.9mg of Trolox equivalents per mL were recorded in Ethiopian and Indian Nigella seeds respectively.
