Isolation and Characterization of Bacoside A from Bacopa monnierifor its Antioxidantand Acetyl-cholinesterase Inhibition Activity as Implicated in Neurodegenerative Diseases

Sukriti Srivastava; Deeksha Gopaliya; Sunil K. Khare

Authors

Sukriti Srivastava Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016, India
Deeksha Gopaliya Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016, India
Sunil K. Khare Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016, India

Keywords:

Acetylcholinesterase, Alzheimer’s disease, Antioxidant activity, Bacoside A, Isolation

Abstract

Bacopa monnieri (Brahmi), is a medicinal plant used in the treatment of neurode generative disorders, metabolic diseases, and inflammation from ancient times. The major bioactive compound, responsible for its pharmacological properties is bacoside A, which is a mixture of four saponins: bacoside A3, bacopaside II, jujubogenin isomer of bacopasaponin C (bacopaside X), and bacopasaponin C. Along with bacoside A, other saponins, d-mannitol, Acid A, monnierin and bacoside B are also present. Owing to its pharmacological role in improving cognitive ability, we aimed to isolate bacoside A from Bacopa monnieri and further characterize it. A high yielding procedure for the isolation of bacoside A was developed. A bacoside-richfraction was extracted from the Brahmi tablet (HimalayaTM), by solvent polarity gradient method,and bacoside A was isolated from the crude extract employing gradient silica gel (100-200 mesh size) column chromatography. Bacoside A was obtained at a methanol concentration of 18-21% in the ethyl acetate mobile phase as confirmed by high-performance thin-layer chromatography. A yield of 92.8 mg bacoside A per gram of crude Brahmi extract was obtained. The total bacoside A content in the isolate was 83.46% as estimated by HPLC. High-performance liquid chrom atography established its linearity along the concentration range 0 to 500 µg/mL and showed similar peaks in standard and isolated bacoside A. Fourier transform infrared spectra also depicted the presence of identical functional groups in both standard and the isolated bacoside A. The isolated bacoside A proved to be a potential acetylcholinesterase inhibitor, having an IC50 value of 9.96 µg/mL. It also proved to be a potent anti-oxidant with the IC50 value of 73.28 µg/mL. The admet SAR tool gave the estimation of the possible toxicity profile of the phytoconstituents of bacoside A.