Changes in lipolysis and hormone-sensitive lipase expression caused by procyanidins in 3T3-L1 adipocytes

OBJECTIVE: To find out whether lipid stores are influenced by phenolic compounds in wine. DESIGN: Differentiated 3T3-L1 cells were treated with catechin, epicatechin or procyanidin extracts with different degrees of polymerization at 150 mu M for different periods of time (0.5-24 h). SUBJECTS: Cell line 3T3-L1. MEASUREMENTS: Cellular viability, glycerol-phosphate dehydrogenase activity, glycerol release in the medium, HSL mRNA levels, triacylglycerols and protein. RESULTS: Catechin, epicatechin and procyanidin extracts were not toxic for the 3T3-L1 cells in the conditions assayed. Glycerol-3-phosphate dehydrogenase activity was markedly decreased by 150 mu M procyanidin extracts. The release of glycerol into the medium was increased in 150 mu M procyanidin extract-treated cells and reached a plateau after 15h exposure. Procyanidins caused a time-dependent reduction in the HSL mRNA levels. CONCLUSIONS: These results suggest that procyanidins from grape and wine affect lipid metabolism whilst their monomers (catechin and epicatechin) do not. This effect is more pronounced when the degree of polymerization is higher. Procyanidin extracts cause a time-dependent reduction in the HSL mRNA levels, inhibit triacylglycerol synthesis and also favour triacylglycerol hydrolysis until the HSL mRNA had reached very low levels.