title: Effect of exogenous ATP on Momordica charantia Linn. (Cucurbitaceae) induced inhibition of D-glucose, L-tyrosine and fluid transport across rat everted intestinal sacs in vitro.
abstract: Momordica charantia (MC) is a common oriental vegetable with known antidiabetic, laxative and antimicrobial properties. This study investigates the effects of aqueous fruit extract of MC on the transport of d-glucose, l-tyrosine and fluid across rat-everted intestine in vitro. Everted intestinal sacs from rats were mounted in an organ bath containing Krebs-Henseleit bicarbonate buffer. Graded concentrations (1.5-12mg/ml) of MC fruit extract were incubated in the mucosal solution with and without exogenous ATP in the mucosal bathing fluid. The serosal appearance and mucosal disappearance of d-glucose, l-tyrosine and the fluid absorptive capacity of the intestine were significantly inhibited (p<0.05) with increasing graded concentrations of MC. The concentration of d-glucose accumulated or metabolized by the enterocytes in the intestinal tissues were significantly higher (p<0.05) when incubated with MC. Increasing graded concentrations of exogenous ATP (25-200 microM) were incubated with 3.0mg/ml MC to confirm inhibition of the ATP-dependent active transport of d-glucose, l-tyrosine and fluid across rat enterocytes. It was found that increasing concentrations of mucosal ATP from 25 to 100 microM significantly (p<0.05) reverses the MC-depression of the d-glucose, l-tyrosine and fluid uptake across rat everted intestinal sacs. It is hypothesized that bioactive phytochemicals such as saponins in MC fruit extract inhibits the active transport of d-glucose, l-tyrosine and fluid across rat intestine by inhibiting the production of ATP responsible for the active transport of these molecules. It is likely that MC can be a potential alternative drug therapy of postprandial hyperglycaemia via inhibition of glucose uptake across the small intestine.
authors.affiliation: Department of Health Sciences, University of Mauritius, Reduit, Mauritius.
authors.forename: M F
authors.initials: MF
authors.lastname: Mahomoodally
authors.forename: A
authors.initials: A
authors.lastname: Gurib-Fakim
authors.forename: A H
authors.initials: AH
authors.lastname: Subratty
mesh_terms: D000255:Adenosine Triphosphate / Q000502:physiology*; D000818:Animals; D001692:Biological Transport / Q000187:drug effects*; D005638:Fruit; D005947:Glucose / Q000378:metabolism*; D006943:Hyperglycemia / Q000188:drug therapy; D007408:Intestinal Absorption / Q000187:drug effects*; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D029777:Momordica charantia / Q000737:chemistry; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D012503:Saponins / Q000494:pharmacology; D014443:Tyrosine / Q000378:metabolism
chemical_list: D010936:Plant Extracts; D012503:Saponins; D014443:Tyrosine; D000255:Adenosine Triphosphate; D005947:Glucose