Cyanidin inhibits adipogenesis in 3T3-L1 preadipocytes by activating the PLC-IP3 pathway

by Selleckchem | Jul 11 2023

Cyanidin is the most abundant anthocyanin found in red-purple plants and possesses anti-obesity properties. However, its mechanism of action in adipocytes remains unknown. The objective of this study was to elucidate how cyanidin inhibits adipocyte formation in 3T3-L1 preadipocytes. Cells were cultured in adipogenic differentiation medium supplemented with cyanidin and examined for adipogenesis, cell viability, and adipocyte gene expression using Oil Red O staining, MTT assay, and RT-qPCR. Real-time Ca2+ imaging analysis was performed in living cells to elucidate cyanidin's mechanism of action. The results demonstrated that cyanidin (1-50 μM) supplementation to the adipogenic medium inhibited adipogenesis by downregulating adipogenic marker gene expression (PPARγ, C/EBPα, adiponectin, and aP2) without affecting cell viability after 4 days of treatment. Stimulation of cells with cyanidin (30-100 μM) increased intracellular Ca2+ in a concentration dependent manner with peak calcium increases at 50 μM. Pretreatment of cells with the phospholipase C (PLC) inhibitor U73122, inositol triphosphate (IP3) receptor blocker 2-APB, and depletion of endoplasmic reticulum Ca2+ stores by thapsigargin abolished the Ca2+ increases by cyanidin. These findings suggested that cyanidin inhibits adipocyte formation by activating the PLC-IP3 pathway and intracellular Ca2+ signaling. Our study is the first report describing the mechanism underlying the anti-obesity effect of cyanidin.

Comments:

The study you described aimed to investigate the mechanism by which cyanidin inhibits adipocyte formation in 3T3-L1 preadipocytes, which are commonly used as a model for studying adipogenesis (the process by which preadipocytes differentiate into mature adipocytes). The researchers examined the effects of cyanidin supplementation on adipogenesis, cell viability, and gene expression related to adipocyte formation.

The results of the study showed that cyanidin, when added to the adipogenic differentiation medium, effectively inhibited adipogenesis. Adipogenesis was assessed using Oil Red O staining, which is a method commonly used to visualize lipid droplets that accumulate during adipocyte differentiation. The researchers found that cyanidin supplementation downregulated the expression of adipogenic marker genes such as PPARγ, C/EBPα, adiponectin, and aP2. These genes are known to play crucial roles in adipocyte differentiation and function.

Importantly, the study found that cyanidin's inhibition of adipogenesis was not due to cytotoxic effects, as cell viability remained unaffected after four days of treatment with cyanidin.

To further investigate the mechanism of action of cyanidin, the researchers performed real-time Ca2+ imaging analysis in living cells. They observed that cyanidin stimulation caused a concentration-dependent increase in intracellular Ca2+ levels. The peak increase in intracellular Ca2+ occurred at a concentration of 50 μM cyanidin.

To determine the involvement of specific signaling pathways in cyanidin-induced Ca2+ increase, the researchers conducted additional experiments. They pretreated the cells with inhibitors targeting the phospholipase C (PLC) pathway (U73122) and the inositol triphosphate (IP3) receptor (2-APB). They also depleted endoplasmic reticulum Ca2+ stores using thapsigargin. These treatments effectively abolished the cyanidin-induced Ca2+ increases, suggesting that cyanidin activates the PLC-IP3 pathway and relies on intracellular Ca2+ signaling to inhibit adipocyte formation.

Overall, this study provides insights into the mechanism underlying the anti-obesity effect of cyanidin. The findings suggest that cyanidin inhibits adipogenesis by downregulating adipogenic marker gene expression and activating the PLC-IP3 pathway, leading to intracellular Ca2+ signaling. This research contributes to our understanding of the potential therapeutic properties of cyanidin in the context of obesity.