Identification of anti-adipogenic withanolides from the roots of Indian ginseng (Withania somnifera).

Background: Withania somnifera (Solanaceae), generally known as Indian ginseng, is a medicinal plant that is used in Ayurvedic practice for promoting health and longevity. This study aims to identify the bioactive metabolites from Indian ginseng and elucidate their structures. Methods: Withanolides were purified by chromatographic techniques, including HPLC coupled with LC/MS. Chemical structures of isolated withanolides were clarified by analyzing the spectroscopic data from 1D and 2D NMR, and HR-ESIMS experiment. Absolute configurations of the withanolides were established by the application of NMR chemical shifts and ECD calculations. Anti-adipogenic activities of isolates were evaluated using 3T3-L1 preadipocytes with Oil Red O staining and quantitative real-time PCR (qPCR). Results: Phytochemical examination of the roots of Indian ginseng afforded to the isolation of six withanolides (1-6), including three novel withanolides, withasilolides G-I (1-3). All the six compounds inhibited adipogenesis and suppressed the enlargement of lipid droplets, compared to those of the control. Additionally, the mRNA expression levels of Fabp4 and Adipsin, the adipocyte markers decreased noticeably following treatment with 25 µM of 1-6. The active compounds (1-6) also promoted lipid metabolism by upregulating the expression of the lipolytic genes HSL and ATGL and downregulating the expression of the lipogenic gene SREBP1. Conclusion: The results of our experimental studies suggest that the withasilolides identified herein have anti-adipogenic potential and can be considered for the development of therapeutic strategies against adipogenesis in obesity. Our study also provides a mechanistic rationale for using Indian ginseng as a potential therapeutic agent against obesity and related metabolic diseases.

Discovery of Dihydrophaseic Acid Glucosides from the Florets of Carthamus tinctorius.

Carthamus tinctorius L. (Compositae; safflower or Hong Hua) has been used in Korean traditional medicine for maintaining the homeostasis of body circulation. Phytochemical investigation was performed on the florets of C. tinctorius by liquid chromatography-mass spectrometry (LC/MS), which afforded two dihydrophaseic acid glucosides (1 and 2). Isolated compounds were structurally confirmed using a combination of spectroscopic methods including 1D and 2D nuclear magnetic resonance and high-resolution electrospray ionization mass spectroscopy. Their absolute configurations were established by quantum chemical electronic circular dichroism calculations and enzymatic hydrolysis. The anti-adipogenesis activity of the isolated compounds was evaluated using 3T3-L1 preadipocytes. Treatment with the dihydrophaseic acid glucoside (1) during adipocyte differentiation prevented the accumulation of lipid droplets and reduced the expression of adipogenic genes, Fabp4 and Adipsin. However, compound 2 did not affect adipogenesis. Our study yielded a dihydrophaseic acid glucoside derived from C. tinctorius, which has potential advantages for treating obesity.

Ginsenoside Rg3 Induces Browning of 3T3-L1 Adipocytes by Activating AMPK Signaling.

Ginsenoside Rg3, one of the major components in Panax ginseng, has been reported to possess several therapeutic effects including anti-obesity properties. However, its effect on the browning of mature white adipocytes as well as the underlying mechanism remains poorly understood. In this study, we suggested a novel role of Rg3 in the browning of mature 3T3-L1 adipocytes by upregulating browning-related gene expression. The browning effects of Rg3 on differentiated 3T3-L1 adipocytes were evaluated by analyzing browning-related markers using quantitative PCR, immunoblotting, and immunostaining. In addition, the size and sum area of lipid droplets in differentiated 3T3-L1 adipocytes were measured using Oil-Red-O staining. In mature 3T3-L1 adipocytes, Rg3 dose-dependently induced the expression of browning-related genes such as Ucp1, Prdm16, Pgc1α, Cidea, and Dio2. Moreover, Rg3 induced the expression of beige fat-specific genes (CD137 and TMEM26) and lipid metabolism-associated genes (FASN, SREBP1, and MCAD), which indicated the activation of lipid metabolism by Rg3. We also demonstrated that activation of 5' adenosine monophosphate-activated protein kinase (AMPK) is required for Rg3-mediated up-regulation of browning gene expression. Moreover, Rg3 inhibited the accumulation of lipid droplets and reduced the droplet size in mature 3T3-L1 adipocytes. Taken together, this study identifies a novel role of Rg3 in browning of white adipocytes, as well as suggesting a potential mechanism of an anti-obesity effect of Panax ginseng.