Anti-Wrinkle Activity of Clausena harmandiana Essential Oil and Development of a Bioactive Nano-Drug Delivery System for Cosmetic Applications

Background: Clausena harmandiana (Song Fa) leaves are a source of essential oil, in which the dominant compound is trans-anethole and reported the high antioxidant activity but the inhibition of biological enzymes related to anti-wrinkle activity is limit. Objectives: The objectives of this study are to investigate the ability of Song Fa leaf essential oil (SFEO) to inhibit enzymes that cause skin wrinkles and then to develop a bioactive ingredient in a nano-drug delivery system for anti-ageing cosmetic products. Methods: Fresh leaves of Song Fa were distilled and their essential oil obtained. Then, the anti-collagenase, elastase, and hyaluronidase activities were investigated and compared with those of an oleanolic acid standard. Then, SFEO was developed into a microemulsion by using Tween 80 as a surfactant and ethanol as a co-surfactant in a ratio of 1:1. Results: SFEO presented the highest inhibitory activities against hyaluronidase and collagenase (IC₅₀ 10.94±1.06 and 19.06±0.06 μg/ml, respectively), which were close to those of oleanolic acid (IC₅₀ 7.43±0.58 and 16.75±0.14 μg/ml), followed by elastase (IC₅₀ 121.47±2.80 μg/ml). Two microemulsion formulas with different amounts of essential oil, 1% and 5% w/w, were formulated and evaluated for their enzyme inhibitory activities. The results showed that 5% Song Fa microemulsion inhibited collagenase and elastase (35.78% and 99.35%, respectively) by more than 1% Song Fa microemulsion (34.22% and 92.67%, respectively) and only the 5% Song Fa microemulsion formula exhibited anti-hyaluronidase activity. Conclusion: This information will benefit the development of essential-oil-based products and increase the utilization of medicinal plants in the cosmetic industry.