Antioxidant Activity of Ocimum basilicum L. Under Abiotic Stress Conditions

Abstract

This study investigates changes in the antioxidant capacity of basil (Ocimum basilicum L.) exposed to various abiotic stress factors (50 and 100 mM salinity, drought, and photoperiodic stress). The antioxidant potentials of the prepared methanolic extracts were evaluated using the DPPH radical scavenging assay (7.81–1000 μg/mL). The findings demonstrated that all extracts exhibited strong, dose-dependent activity. Notably, plants subjected to moderate drought and extended photoperiod showed higher DPPH inhibition than ascorbic acid at 62.5 μg/mL under the tested conditions. Salinity treatment induced a biphasic response: it decreased activity at 50 mM but activated the defense system and increased antioxidant capacity at the 100 mM level. In conclusion, stress treatments such as controlled drought and extended photoperiod appear to effectively enhance the non-enzymatic defense systems of Ocimum basilicum, thereby increasing its potential as a natural antioxidant source.