title: Transport in Caco-2 cell monolayers of antidiabetic cucurbitane triterpenoids from Momordica charantia fruits.
abstract: 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.
authors.affiliation: Department of Biological Sciences, Lehman College, and The Graduate Center, The City University of New York, Bronx, New York, USA.
authors.forename: Shi-Biao
authors.initials: SB
authors.lastname: Wu
authors.affiliation: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors.forename: Grace G L
authors.initials: GG
authors.lastname: Yue
authors.affiliation: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors.forename: Ming-Ho
authors.initials: MH
authors.lastname: To
authors.affiliation: Department of Biological Sciences, Lehman College, and The Graduate Center, The City University of New York, Bronx, New York, USA.
authors.forename: Amy C
authors.initials: AC
authors.lastname: Keller
authors.affiliation: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors.forename: Clara B S
authors.initials: CB
authors.lastname: Lau
authors.affiliation: Department of Biological Sciences, Lehman College, and The Graduate Center, The City University of New York, Bronx, New York, USA.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Kennelly
mesh_terms: D001692:Biological Transport; D018938:Caco-2 Cells; D002851:Chromatography, High Pressure Liquid; D003920:Diabetes Mellitus / Q000188:drug therapy*; D005638:Fruit / Q000737:chemistry; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D013058:Mass Spectrometry; D029777:Momordica charantia / Q000737:chemistry*; D010946:Plants, Medicinal; D013261:Sterols / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D006027:Glycosides; D007004:Hypoglycemic Agents; D013261:Sterols; D014315:Triterpenes; C514277:cucurbitane; C506900:momordicine I