2',4'-Dihydroxy-6'-methoxy-3',5'-dimethylchalcone promoted glucose uptake and imposed a paradoxical effect on adipocyte differentiation in 3T3-L1 cells.

2',4'-Dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC), one of the flavonoids isolated and purified from the dried flower buds of Cleistocalyx operculatus, was explored for its function in glucose uptake/glycogen synthesis in insulin-sensitive tissue cells and its effect and mechanism on 3T3-L1 preadipocyte differentiation. DMC (10 μM) treatment remarkably promoted glucose uptake in differentiated 3T3-L1 adipocytes (P < 0.05 vs control group), whereas the glucose uptake in L6 myoblasts and glycogen synthesis in HepG2 hepatocytes were not affected by the treatment.

HPLC-FLD determination of NBD-cholesterol, its ester and other metabolites in cellular lipid extracts.

22-[N(-7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-23,24-bisnor-5-cholen-3β-ol (NBD-cholesterol), a fluorescent cholesterol analog, was an extragenous cholesterol tracer used to study cholesterol absorption and metabolism in cultured cells. In order to measure free intracellular cholesterol and its esters, a precise and sensitive method employing high-performance liquid chromatography/fluorescence detection (HPLC-FLD) was developed for the first time. Method validation showed a limit of detection at 30 ng/mL.

[Proliferation inhibition of lambda-carrageenan oligosaccharides on HUVEC and expression of apoptotic relevant genes].

To study the anti-proliferation effect of lambda-carrageenan oligosaccharides (lambda-CO) on human umbilical vein endothelial cells (HUVECs) and expression of apoptotic relevant genes, the influence of lambda-CO on HUVECs proliferation was measured by MTT assay; apoptotic rate, cell cycle distribution and the level of active caspase-3 of HUVECs were analyzed using flow cytometry; the mRNA level of apoptosis related genes was determined by RT-PCR. At a high concentration of 1 mg x mL(-1), lambda-CO significantly inhibited the endothelial cell proliferation. Annexin-V FITC/PI double stain assay showed that when treated with 0, 0.