Effectiveness and Safety of Boesenbergia rotunda Extract on 3T3-L1 Preadipocytes and Its Use in Capsaicin-Loaded Body-Firming Formulation: In Vitro Biological Study and In Vivo Human Study

Boesenbergia rotunda has been used as an antiobesity agent by suppressing adipogenesis. This study aimed to investigate the biological activity of B. rotunda on preadipocyte cells and to evaluate the effectiveness and safety of using B. rotunda extract in a capsaicin-loaded body-firming formulation. The antiadipogenesis of B. rotunda ethanolic extract was evaluated in 3T3-L1 preadipocyte cells. After the application of the B. rotunda extract-loaded body-firming formulation on the skin of volunteers for 28 d, thigh circumference, melanin index, and skin erythema were investigated. The results showed that the ethanolic extract of B. rotunda was not toxic toward 3T3-L1 cells at concentrations lower than 20 µg/mL, with antiadipogenesis of the B. rotunda extract occurring at a concentration of 1 µg/mL. The B. rotunda extract containing panduratin A was mixed with capsaicin body-firming products and successfully permeated into and through the skin. Applying this formulation to the thighs of the volunteers two times a day for 21 days led to a significant reduction in thigh circumference and melanin index. A slight elevation in skin erythema was observed, but there was no significant increase in redness or pain. In conclusion, the B. rotunda extract contained bioactive compounds that inhibited antiadipogenesis. The formulations containing B. rotunda extract and capsaicin showed potential as effective body-firming products.