Figure 8.

Effect of the C. sinensis extract (CsEx) on collagen production during 28-day topical application. Collagen index average percentage variation vs. D₀ recorded for 20 volunteers throughout the study period (after 7, 14, and 28 days of treatment) for CsEx and placebo, intra-group difference t-test * p < 0.05, ** p < 0.01, *** p < 0.001), and inter-group difference ANOVA test ^$ p < 0.05, ^$$ p < 0.01). The images of forehead wrinkles over a 28-day treatment with 6 mg/L CsEx vs. placebo were obtained with a Visia 7th (Canfield Scientific Inc., Parsippany, NJ, USA).