Identification of Main Phenolic Compounds of Nitraria Retusa Leaf and Stem Extracts and Evaluation of Their Anti-Adipogenic Activity in 3T3-L1 Cells

Abstract

The edible halophyte Nitraria retusa known in traditional medicine purposes was used as a support in this study. The present study investigated the chemical analyses of the general composition of leaf and stem extracts using RP-HPLC. Results showed the richness of these extracts in phenolics especially flavonoids as luteolin-7-O-glucoside, isorhamnetin-3-O-rutinoside, isorhamnetin, quercetin and others. In total, nine compounds were identified for each organ extract. Luteolin-7-O-glucoside, isorhamnetin-3-O-rutinoside and Isorhamnetin are three flavonoids which are common in leaves and stems. Adipogenesis assay was performed to investigate the effect of organs, as well as the three last compounds on the adipocyte differentiation and on the lipid droplets accumulation in 3T3-L1 cells. Based on Oil-Red-O content quantification in 3T3-L1 cells, results showed that each extract of N. retusa at 25, 50, 100, 200 and 400 μg/mL could not inhibit the lipid droplet accumulation compared to untreated cells, in dose dependent manner. However, compounds showed better effect especially with isorhamnetin even with 5μM. Moreover, the effect of extracts and single bioactive components on cell proliferation of 3T3-L1 cells showed that stem extract was more efficient than leaf one. Besides, according to morphological observation, isorhamnetin strongly and significantly affected cell proliferation.