Comparison of Total Flavonoid, Phenolic Content and Antioxidant Capacity in Leaf and Seed Extracts from White Holy Basil (Ocimum sanctum).

ABSTRACT

Ocimum sanctum, commonly known as the white holy basil herb belonging to Lamiaceae family is one of the oldest and popular medicinal plant rich in various phytonutrients and antioxidants. In this study, the comparative evaluation of flavonoids, phenolic content, and antioxidant capacity was carried out in methanolic extract prepared from O. sanctum leaves and seeds. The TAC, TPC, and the TFC were measured by ammonium molybdate, Folin-Ciocalteau and aluminum chloride method respectively. Antioxidant activity was also determined by using DPPH and FRAP assay. In response to the above assays, TACs of O. sanctum leaf and seed extracts were 25-248 and 0.011-0.109 μg AAE/10 mg of extract respectively. The TFC assay showed that leaf extract of O. sanctum (14- 225 μg QE/10mg extract) had higher flavonoid content than the seed extract (0.009-0.119 μg QE/10 mg extract) and the TPC assay in the leaf extract (4.49-9.31 μg GAE/mg extract) was higher than those present in seed (4.10-9.05 μg GAE/mg extract). In DPPH assay, % inhibition in O. sanctum leaf extract was determined in the range 18-76% while in seed extract it was 6-29% and in FRAP assay, leaf extract displayed reducing power in range 0.48- 5.50 μg FSE /mg extract while in seed extract it was 0.16-5.46 μg FSE /mg extract. It was observed that O. sanctum leaf extract had high total phenolic and flavonoid content in addition to antioxidant capacity as compared to its seed extract. Abbreviations TAC Total Antioxidant Capacity TPC Total Phenolic Content TFC Total Flavonoid Content DPPH 2, 2-diphenyl-1-picryhydrazyl FRAP Ferric Reducing/Antioxidant Power