A Comparative Evaluation of the Antioxidant and Phytochemical Properties of Various Extracts of Ocimum Sanctum Linn Grown in Jaffna District, Sri Lanka

Abstract

Background and Aim: Ocimum sanctum Linn (O. sanctum) (Lamiaceae) is a valuable medicinal herb. It contains several therapeutic characteristics due to its bioactive components. This study aimed to compare the phytochemical and antioxidant properties of different extracts of the leaves and flowers of the O. sanctum plant, which grows in Sri Lanka. Materials and Methods: Standard procedures were followed for the qualitative and quantitative phytochemical analyses and the DPPH as well as ABTS antioxidant activities. Results: The findings demonstrated that the ethanolic and methanolic extracts had adequate concentrations of flavonoids, phenols, tannins, and alkaloids compared with the aqueous extracts of the flowers and leaves of O. sanctum. The supreme quantity of the flavonoid content existed in the ethanolic flower extracts (50.88±0.62 µg QE/g) and methanolic leaf extract (49.11±0.27 µg QE/g), while the higher amount of the phenol content (20.96±0.65 µg GAE/g) was found in the ethanolic leaf extract. The methanolic leaf extract had the highest tannin content (409.95±0.66 µg TAE/g) compared with other extracts. Moreover, the highest amount of alkaloid was observed in flowers (75.83±0.55 mg/g) and not in leaves (52.60±0.66 mg/g). Furthermore, the methanolic flower extract exhibited the greatest DPPH (IC50: 0.68±0.19μg/mL) and ABTS (IC50: 1.82±0.32μg/mL) activities compared with the Trolox. Conclusion: The present study proved that although the leaf extracts contained higher concentrations of phytochemicals, the methanolic flower extract of O. sanctum had a greater potential for antioxidants than the methanolic leaf extract.