Polyphasic approaches to identify and understand α-glucosidase inhibitory potential of secondary metabolites of Withania coagulans fruit

Monu Dinesh Ojha; Ajay Yadav; Bhani Kongkham; Duraivadivel Prabhakaran; Shivajirao L Gholap; Vikas Kumar; Krishna K Inampudi; P Hariprasad

doi:10.1016/j.ijbiomac.2024.135718

Polyphasic approaches to identify and understand α-glucosidase inhibitory potential of secondary metabolites of Withania coagulans fruit

Int J Biol Macromol. 2024 Sep 16;280(Pt 1):135718. doi: 10.1016/j.ijbiomac.2024.135718. Online ahead of print.

Authors

Monu Dinesh Ojha¹, Ajay Yadav¹, Bhani Kongkham¹, Duraivadivel Prabhakaran¹, Shivajirao L Gholap², Vikas Kumar³, Krishna K Inampudi³, P Hariprasad⁴

Affiliations

¹ Centre for Rural Development and Technology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
² Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
³ Department of Biophysics, All India Institute of Medical Science, New Delhi 110016, India.
⁴ Centre for Rural Development and Technology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. Electronic address: phari@iitd.ac.in.

PMID: 39293614
DOI: 10.1016/j.ijbiomac.2024.135718

Abstract

Withania coagulans (WC) is used in traditional and Ayurveda medicine to treat various ailments, including diabetes. Our investigation found that WC fruit hexane extract effectively suppresses α-glucosidase activity (IC₅₀ = 0.013 mg/ml, K_i = 0.012 mg/ml). The purified molecule has an IC₅₀ of 0.004 mg/ml and K_i of 0.0037 mg/ml. FTIR examination indicates distinctive peaks at 3500, 2900, 1770, and 1500 cm^-1 corresponding to functional groups OH bending, CH stretching, CO stretching, and CO stretching. GCMS analysis reveals plant secondary metabolites (PSM) such as n-hexadecenoic acid and methyl 9,10-octadecadienoate. NMR confirms the existence of olefinic fatty acids. The bioactive fraction recorded a non-competitive mode of inhibition of α-glucosidase activity. The cytotoxicity exhibited against HELA cell was IC₅₀ 0.4 mg/ml and found positive in inhibiting the growth of Bacillus cereus, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa. Additionally, ensemble docking and molecular dynamic simulation showed that, out of the four PSMs examined, methyl 12,13-tetradecadienoate interacted with the α-glucosidase enzyme's allosteric site (BE -128.78 kJ/mol) and changed the configurations of the catalytic sites, as demonstrated by the enzyme's decreased affinity for isomaltose. The study found that PSMs from WC fruit may inhibit α-glucosidase, making them viable candidates for antidiabetic medication development.

Keywords: Binding energy; Chromatography; Molecular dynamics simulation; Non-competitive inhibition; Plant secondary metabolites; α-Glucosidase inhibitor.