Cucurbitane-type compounds from Momordica charantia: Isolation, in vitro antidiabetic, anti-inflammatory activities and in silico modeling approaches

Abstract

Momordica charantia L., commonly known as bitter melon, belongs to the Cucurbitaceae family. Various in vitro and in vivo studies have indicated that extracts of bitter melons have anti-diabetic properties. However, very little is known about the specific purified compounds responsible for these antidiabetic properties. In the present study, 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al, charantal, charantoside XI, and 25ξ-isopropenylchole-5, 6-ene-3-O-d-glucopyranoside were isolated from bitter melon fruit. The structures of the purified compounds were elucidated by HR-ESIMS, 1D, and 2D NMR experiments. All compounds exhibited significant inhibition of α-amylase and α-glucosidase comparable to acarbose. Molecular docking studies demonstrated that purified compounds were able to bind to the active sites of proteins. Additionally, the purified compounds showed significant anti-inflammatory activity, downregulating the expression of NF-κB, iNOS, IL-6, IL-1β, TNF-α, and Cox-2 in lipopolysaccharide-activated macrophage RAW 264.7 cells. Our findings suggest that the purified compounds have potential anti-diabetic and anti-inflammatory activities and therefore hold promise for the development of plant-based management for diabetic and inflammatory conditions.

Keywords: Bitter melon; Cucurbitaceae; Molecular docking; Murine macrophages; Triterpene aglycones.