In vitro Screening for Acetylcholinesterase Inhibition and Antioxidant Potential in Different Extracts of Sage (Salvia officinalis L.) and Rosemary (Rosmarinus officinalis L.)

Abstract

Sage and rosemary, used as spice and food preservatives, are the rich sources of polyphenolic compounds that possess a substantial cognitive and antioxidant property. Rosmarinic acid present in sage and rosemary found to inhibit acetylcholinesterase (AChE) enzyme, having a neuroprotective effect against Alzheimer’s disease. The study aimed to evaluate different methods of extraction such as fresh aqueous extraction, decoction, Soxhlet extraction, including fermentation and sonic extractions on total phenolic content, acetylcholinesterase inhibition and antioxidant activity in sage and rosemary. Among the different extracts, significantly higher total phenols were observed in Soxhlet extraction with methanol in both sage and rosemary in terms of gallic acid equivalents- GAE (64.51±1.72 and 76.64±2.2 mg GAE.g^-1, respectively). Antioxidant capacity was also recorded maximum in the same treatment, expressed in Trolox equivalents (112.81± 6.43 and 198.08±8.71 mg TE.g^-1 in Sage and Rosemary, respectively). IC₅₀ of DPPH in the sample was significantly lower (0.13±0.01 and 0.06±0.00 mg.ml^-1 in sage and rosemary, respectively) in Soxhlet extraction than other methods and it was compared with Trolox (0.0135±0.00 mg.ml^-1). Significantly high acetylcholinesterase inhibition was noticed in Soxhlet extract (24.04±0.55 and 8.57±0.82 mg.ml-1 in sage and rosemary, respectively) and it was compared with galantamine (6.33 μg.ml^-1) as a positive control.

GRAPHICAL ABSTRACT

Key words:

• AChE
• antioxidant activity
• Soxhlet extraction
• sage
• rosemary