Antioxidant and anticholinesterase effects of rosemary (Salvia rosmarinus) extract: A double-blind randomized controlled trial

Objective: The present study was aimed at investigating the effect of Salvia rosmarinus (syn: Rosmarinus officinalis L.; rosemary) extract on acetyl cholinesterase (AChE) activity and oxidative stress biomarkers in healthy volunteers. Method: In a double-blind randomized controlled trial, 50 healthy participants (21-25 years old) were divided into two groups: placebo (N = 25) and rosemary (N = 25). The rosemary and placebo groups respectively received rosemary (500 mg rosemary powder) and placebo capsules (500 mg starch powder) twice a day for one month. AChE activity, total antioxidant capacity (TAC), lipid peroxidation, and protein carbonylation were determined in blood samples before and after the trial.Discussion: Administration of 1000 mg of rosemary for 30 days significantly decreased AChE activity compared to AChE activity before rosemary treatment (p value < 0.001) and also in the placebo group (p value < 0.01). Notably, administration of rosemary considerably improved TAC (p value < 0.01) and protein carbonylation (p value < 0.05) compared to those values before rosemary treatment and in the placebo group. After administration of rosemary, no significant changes were observed in lipid peroxidation (p value > 0.05) compared to that value before rosemary treatment and in the placebo group.Conclusion: The findings indicated the inhibitory effect of rosemary on AChE activity and the improvement of non-enzymatic antioxidant defense system. The results may reinforce the use of rosemary as a potential antioxidant supplement. Further evaluations are recommended to find out the effectiveness of rosemary in patients with Alzheimer's disease.(c) 2021 Elsevier Ltd. All rights reserved.