Polyphenols from Indian cereal grains inhibit 3T3-L1 adipogenesis through modulating early and late phase adipogenic markers

Abstract

Cereal grains, millets in particular, are known to contain health-beneficial phenolic compounds. Despite the fact that various studies have been performed worldwide, the need of hour is to find the benefecial effect of dietary polyphenols against obesity, which is a serious health concern.The current study aimed to investigate the anti-adipogenic effect of the polyphenols of selected cereal grains (pearl millet, proso millet, little millet, kodo millet, barnyard millet, and foxtail millet) using 3T3-L1 adipocytes. Polyphenols were extracted from six different cereal grains using different solvents under various conditions. The anti-adipogenic effect of polyphenol-rich extracts from grains was evaluated by means of analyzing lipid accumulation using oil red-O staining, triglycerides content, and the expression of adipogenic markers in 3T3-L1 cells. The total polyphenol content was comparatively higher in ethanol (80%) extracts of the millets. The polyphenolic profile of millets on HPLC revealed different compositions of phenolic compounds in each grain, which mainly included the phenolic acids and the flavonoids. Ethanol extract of proso millet significantly suppressed the intracellular lipid accumulation, and also the triglycerides content. Further, the grain polyphenolic compounds significantly down-regulated the expression of PPARγ, CEBPα, FAS, SREBP-1c, and pSREBP at both the early and late phase of adipogenesis. It is understood from our study that cereal grain polyphenols have the potential to redress the adipogenic effect in vitro.