LAUSR

BACKGROUND The wild bitter gourd (WBG) is a commonly consumed vegetable in Asia, which has antioxidant and hypoglycemic properties. The aim of the present study was to investigate anti-adipogenic activities of isolated compounds from WBG on 8-day differentiated cultures of 3T3-L1 adipocytes and then stained with Oil Red O (ORO) or diamidino-2-phenylindole (DAPI). RESULTS ORO stains of the methanol extracts of de-seeded HM86 cultivar of WBG (WBG-M) and the ethyl acetate fractions (WBG-M-EA) showed anti-adipogenic activities against differentiated adipocytes. Two chlorophyll-degraded compounds, pheophorbide a (1) and pyropheophorbide a (2), were isolated from WBG-M-EA. The treatments of 1 (5, 10, and 20 μmol L-1 ) and 2 (2.5, 5, and 10 μmol L-1 ) showed dose-dependent reductions in lipid accumulations and reduced nuclear DAPI stains in differentiated 3T3-L1 adipocytes. The concentrations for 50% inhibition against lipid accumulations of 1 and 2, respectively, were 16.05 and 7.04 μmol L-1 . The 1 and 2 treatments showed enhanced lactate dehydrogenase releases in the first 4-day cell mitotic clonal expansions during the differentiating cultural processes, but the effect was less on the non-differentiating cultural processes. Thus, 1 and 2 were more toxic to differentiating adipocytes rather than non-differentiated pre-adipocytes, which in parts resulted in the anti-adipogenic activities with lowered lipid accumulations. CONCLUSION Both 1 and 2 showed anti-adipogenic activities in cell models. These chlorophyll-degraded compounds commonly exist in several vegetables during storage or edible seaweeds, which will provide resources for further investigations to test anti-obesity in animal studies. This article is protected by copyright. All rights reserved.