Evaluation of Antioxidant, Radical-Scavenging and Acetylcholinesterase Inhibitory Activities of Various Culinary Herbs Cultivated in Southern Turkey

The purpose of this study was to determine the antioxidant, radical‐scavenging, and acetylcholinesterase inhibitory capabilities of water and methanol extracts of Rhus coriaria L., Ocimum basilicum L., Rosmarinus officinalis L., Salvia officinalis L. and Thymbra spicata L., which are grown in the Hatay province of Turkey. Total antioxidant activities were evaluated using 2,2‐diphenyl‐1‐picrylhydrazyl (22–782.6 μg/mL EC50),·OH scavenging (3.93–33.43 μg/mL EC50), ferric (0.143–3.083 mmol trolox equivalent (TE)/g), and cupric‐reducing antioxidant power (0.143–3.083 mmol TE/g) assays. The phenolic composition of the methanolic extract of R. coriaria leaves was also investigated, and the active compound was identified as 4‐O‐methylgallic acid. The highest IC50 value of acetylcholinesterase inhibitory activity (1.17 ± 0.04 mg/mL) was observed in R. coriaria leaves. Principal component analysis showed that R. coriaria leaves possessed greater antioxidant and anti‐acetylcholinesterase potential as compared with the other evaluated plants. Practical Applications Antioxidants are widely used in the food industry to prevent the formation of toxic oxidation products and prolong shelf life. Because of increasing concern among consumers about the use of synthetic antioxidants, there has been a great interest in the identification and use of natural antioxidants. The present study reveals that Rhus coriaria leaves, which are not commonly used in Mediterranean cuisine, are a promising source of natural antioxidants and could be considered as a potential source of anti‐acetylcholinesterase agents and food preservatives. Both the antioxidant and anti‐acetylcholinesterase effects of R. coriaria leaves may be beneficial in the treatment of Alzheimer's disease.