cucurbitane and Diabetes-Mellitus

Bitter melon (Momordica charantia, Cucurbitaceae) is a popular edible medicinal plant, which has been used as a botanical dietary supplement for the treatment of diabetes and obesity in Chinese folk medicine. Previously, our team has proved that cucurbitanes triterpenoid were involved in bitter melon's anti-diabetic effects as well as on increasing energy expenditure. The triterpenoids composition can however be influenced by changes of varieties or habitats.. To clarify the significance of bioactive metabolites diversity among different bitter melons and to provide a guideline for selection of bitter melon varieties, an exploratory study was carried out using a UHPLC-HRMS based metabolomic study to identify chemotypes.. Metabolites of 55 seed samples of bitter melon collected in different parts of China were profiled by UHPLC-HRMS. The profiling data were analysed with multivariate (MVA) statistical methods. Principle component analysis (PCA) and hierarchical cluster analysis (HCA) were applied for sample differentiation. Marker compounds were identified by comparing spectroscopic data with isolated compounds, and additional triterpenes were putatively identified by propagating annotations through a molecular network (MN) generated from UHPLC-HRMS & MS/MS metabolite profiling.. PCA and HCA provided a good discrimination between bitter melon samples from various origins in China. This study revealed for the first time the existence of two chemotypes of bitter melon. Marker compounds of those two chemotypes were identified at different MSI levels. The combined results of MN and MVA demonstrated that the two chemotypes mainly differ in their richness in cucurbitane versus oleanane triterpenoid glycosides (CTGs vs. OTGs).. Our finding revealed a clear chemotype distribution of bioactive components across bitter melon varieties. While bioactivities of individual CTGs and OTGs still need to be investigated in more depth, our results could help in future the selection of bitter melon varieties with optimised metabolites profile for an improved management of diabetes with this popular edible Chinese folk medicine.

Topics: Animals; China; Chromatography, High Pressure Liquid; Diabetes Mellitus; Drugs, Chinese Herbal; Glycosides; Humans; Mass Spectrometry; Medicine, Chinese Traditional; Metabolomics; Molecular Conformation; Momordica charantia; Oleanolic Acid; Triterpenes

Bitter melon, the fruit of Momordica charantia L. (Cucurbitaceae), is a widely-used treatment for diabetes in traditional medicine systems throughout the world. Various compounds have been shown to be responsible for this reputed activity, and, in particular, cucurbitane triterpenoids are thought to play a significant role. The objective of this study was to investigate the gastrointestinal transport of a triterpenoid-enriched n-butanol extract of M. charantia using a two-compartment transwell human intestinal epithelial cell Caco-2 monolayer system, simulating the intestinal barrier. Eleven triterpenoids in this extract were transported from the apical to basolateral direction across Caco-2 cell monolayers, and were identified or tentatively identified by HPLC-TOF-MS. Cucurbitane triterpenoids permeated to the basolateral side with apparent permeability coefficient (P app) values for 3-β-7-β,25-trihydroxycucurbita-5,23(E)-dien-19-al and momordicines I and II at 9.02 × 10(-6), 8.12 × 10(-6), and 1.68 × 10(-6)cm/s, respectively. Also, small amounts of these triterpenoids were absorbed inside the Caco-2 cells. This is the first report of the transport of the reputed antidiabetic cucurbitane triterpenoids in human intestinal epithelial cell monolayers. Our findings, therefore, further support the hypothesis that cucurbitane triterpenoids from bitter melon may explain, at least in part, the antidiabetic activity of this plant in vivo.

Topics: Biological Transport; Caco-2 Cells; Chromatography, High Pressure Liquid; Diabetes Mellitus; Fruit; Glycosides; Humans; Hypoglycemic Agents; Mass Spectrometry; Momordica charantia; Plants, Medicinal; Sterols; Triterpenes