Capsaicin Modulates Adipocyte Cell Differentiation and Inflammatory Gene Expression

Abstract

Objective: Adipose tissue stores lipids necessary for the maintenance of nutritional homeostasis. It is also an endocrine organ that reacts to changes in inflammation and energy status. Capsaicin, the principal bioactive compound in red pepper, has garnered significant attention for its reported anti-obesity, anti-diabetic, anti-oxidant, and anti-inflammatory properties. In this study, we aimed to elucidate the influence and most efficacious dose of capsaicin on the expression of lipid metabolism-related inflammatory proteins and the inhibition of adipocyte cell differentiation. Materials and Methods: Cell viability analysis was performed using CCK-8, cell differentiation was assessed using Oil Red O, and gene expression levels of peroxisome proliferator-activated receptor gamma (PPAR gamma), CCAAT/enhancer binding protein alpha (C/EBP alpha), adiponectin, leptin, cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), nuclear factor kappa B1 (NF-kappa B1), tumor necrosis factor-alpha (TNF-alpha), sirtuin-1 (SIRT-1), transient receptor potential vanilloid receptor 1 (TRPV1), and uncoupling protein 2 (UCP2) were evaluated using quantitative real time polymerase chain reaction (qRT-PCR). Statistical analyses were conducted using GraphPad Prism 5. One-way ANOVA was performed to compare quantitative data between the groups. Results: Capsaicin suppressed preadipocyte-to-adipocyte differentiation and mitigated the release of pro-inflammatory cytokines, particularly at low concentrations. Capsaicin effectively suppressed adiponectin levels at all concentrations but decreased leptin levels at lower concentrations (0.5 mu M and 1 mu M). Capsaicin stimulated the expressions of SIRT1 and TRPV-1 in adipocytes. According to our findings, the most effective capsaicin dose for the regulation of SIRT1 and TRPV-1 expressions appears to be 20 mu M. Conclusion: Capsaicin's effect on proteins regulating adipogenesis is not dose-related, but its inhibitory effect on adiposity-dependent inflammation was more pronounced at low concentrations.