ABSTRACT
Introduction: Ocimum sanctum (OS), known as Holy basil, has been documented to possess neuroprotective, cognition-enhancing and stress relieving effects in animal models. However there is paucity of clinical studies to document these effects. Materials and methods: Effect of OS on parameters related to cognition and stress in humans was evaluated with administration of 300 milligram capsules of ethanolic leaf extracts of Ocimum sanctum (EtOS) or placebo per day, over 30 days. Results: Intra-group comparison of Sternberg and Stroop test showed improvement in both the placebo and EtOS groups, however, the improvement stabilized after day 15 in the placebo group. Intergroup comparison revealed a significant improvement of the following cognitive parameters in the EtOS as compared to the placebo: reaction time (RT) and error rate (ER) of Sternberg test, RT of neutral task of Stroop, RT and ER of interference task of Stroop. The intra-group comparison of P300 latency, salivary cortisol, and State-Trait Anxiety Inventory showed improvement over time in the EtOS group alone, though the inter-group difference was significant in the P300 latency alone. There were no changes in heart rate (HR), ΔHR, or galvanic skin response (GSR) or ΔGSR. Conclusion: Ocimum sanctum leaf extract seems to have potential cognition-enhancing properties in humans.