Comparison of the effect of oligonol, a new lychee fruit‐derived low molecular form of polyphenol, and epigallocatechin‐3‐gallate on lipolysis in rat primary adipocytes

Several polyphenols have been shown to be beneficial in preventing the accumulation of body fat in mammals. This paper reports that adding oligonol, a lychee fruit-derived low-molecular form of polyphenol mixture, has a greater effect on lipolysis in primary adipocytes compared with tea (-)-epigallocatechin-3-gallate (EGCG) alone, accompanied by a significant increase in activation of extracellular signalling-related kinase 1/2 (ERK1/2). However, neither phosphorylation of mitogen-activated protein kinase 1/2 (MEK1/2), a molecule upstream of ERK1/2, nor the level of heme oxygenase-1 (HO-1), a molecule downstream of ERK1/2 was significantly changed between oligonol and EGCG, although the addition of oligonol and EGCG significantly increased the levels of phosphorylated MEK1/2 and HO-1 compared with the non-treated control cells. These results suggest that the coordinated direct effect of mixed polyphenol, which comprises oligonol, on ERK1/2 plays a key role in a greater lipolytic response to oligonol than EGCG alone.