Effect of the Ethyl Acetate Fraction from Ethanol Extract of Aegiceras corniculatum Leaves on Antioxidant and Anti-senescence Ability in Rat Skin

To prepare cream using Aegiceras corniculatum (Linn.) Blanco leaf extract as the active additive and evaluate its antioxidation and anti-aging action in skin, five solvent fractions including petroleum ether, dichloromethane, ethyl acetate, n-butanol and water (by alcohol precipitation) were extracted from 75% ethanol extract of A.corniculatum leaves. Among them, the ethyl acetate fraction with high polyphenol content and total flavonoids and strong radical scavenging ability was screened as the additive to prepare the cream. After continuous application of the cream to the dorsal skin of SD rats, skin samples were collected to determine total superoxide dismutase (T-SOD) activity, hydroxyl radical scavenging ability, malondialdehyde (MDA) content, and hydroxyproline (HYP) and collagen content. Results showed that T-SOD activity, hydroxyl radical scavenging ability and the content of HYP and collagen in the skin tissue from SD rats treated by cream with 2.0% ethyl acetate fraction increased very significantly, but the content of MDA decreased very significantly compared with those of the negative or positive control groups and the 1.0% and 0.5% ethyl acetate fraction treatment groups (P < 0.01). This suggested that the ethyl acetate fraction from A. corniculatum leaves was a potential antioxidant and anti-aging cosmetic additive with an effective dose of 2%, and its mechanism for preventing or postponing skin aging might be through improving T-SOD activity and radical scavenging ability, reducing MDA content, and promoting collagen synthesis.