|Planta Med. 2014 Jul;80(11):907-11. |
|Transport in Caco-2 cell monolayers of antidiabetic cucurbitane triterpenoids from Momordica charantia fruits.[Pubmed: 25116119]|
| 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 Momordicine I and Momordicine 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.|
|Phytomedicine. 2011 Dec 15;19(1):32-7. |
|Saponins from the traditional medicinal plant Momordica charantia stimulate insulin secretion in vitro.[Pubmed: 22133295]|
|The antidiabetic activity of Momordica charantia (L.), Cucurbitaceae, a widely-used treatment for diabetes in a number of traditional medicine systems, was investigated in vitro. Antidiabetic activity has been reported for certain saponins isolated from M. charantia.
METHODS AND RESULTS:
In this study insulin secretion was measured in MIN6 β-cells incubated with an ethanol extract, saponin-rich fraction, and five purified saponins and cucurbitane triterpenoids from M. charantia, 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al (1), Momordicine I (2), Momordicine II (3), 3-hydroxycucurbita-5,24-dien-19-al-7,23-di-O-β-glucopyranoside (4), and kuguaglycoside G (5). Treatments were compared to incubation with high glucose (27 mM) and the insulin secretagogue, glipizide (50 μM). At 125 μg/ml, an LC-ToF-MS characterized saponin-rich fraction stimulated insulin secretion significantly more than the DMSO vehicle, p=0.02. At concentrations 10 and 25 μg/ml, compounds 3 and 5 also significantly stimulated insulin secretion as compared to the vehicle, p≤0.007, and p=0.002, respectively.
This is the first report of a saponin-rich fraction, and isolated compounds from M. charantia, stimulating insulin secretion in an in vitro, static incubation assay.