Background: Skin is the main target of environmental influences, especially chronic exposure to the suns UVA rays which will result in wrinkling, decreased skin elasticity, the appearance of loose skin, and a rough clinical appearance. In the dermal tissue, not only affects collagen fibers but also degradation of elastin fibers occurs through an increase in the MMP-12 enzyme levels called photoaging and is characterized by the accumulation of dystrophic elastin fibers throughout the dermal tissue in a process called Elastosis. Avocado seed (Persea americana Mill.) is a part of the fruit that contains high concentrations of flavonoids, phenols, and tannins, it has the potential as a powerful antioxidant. The aim of the present study is to evaluate the effectiveness of avocado (Persea americana Mill.) seed extract cream 10% inhibiting the increase in MMP-12 enzyme levels and elastosis in hairless male Wistar rats (Rattus norvegicus) which were exposed to ultraviolet A rays. Methods: A Randomized post-test-only control group design was conducted among 30 male Wistar rats for 10 consecutive days. They were divided into 3 groups as follows: group (K) as the negative control without any intervention, group (P1) with UVA rays exposure, and group (P2) with application of avocado (Persea americana Mill.) seed extraxt cream 10% and UVA rays exposure. The UVA dosage used is 5J/cm2 twice a day among P1 and P2 groups. Avocado  (Persea americana Mill.) seed extract 10% was applied to the hairless Wistar rats 4 hours after the exposure of UVA rays. MMP-12 was calculated with Rat MMP-12 ELISA Test. Elastin fiber density was calculated by Imageraster software. Statistical analysis was carried out using SPSS version 25 in measure means, normality test, homogeneity test, and comparative test. Results: The results showed that the average MMP-12 enzyme level in the 10% avocado seed cream (P2) group 18.138 ± 0.168% was significantly different from the (K) group 1.073 ± 0.1553% as the negative control and the (P1) group 33.454 ± 1.068%. The mean density of elastin fiber in the cream of avocado seed extract group (P2) 12.42 ± 3.672% was significantly different from the group (K) 20.08 ± 4.994% and group (P1) 26.30 ± 6.822%. Comparative analysis using the Kruskal Wallis test for MMP-12 and the One Way Annova test for elastin fibers showed a p-value of < 0.05, thus indicating a significant difference between groups after treatment. The Least Significance Difference (LSD) test showed that there was a significant difference between the cream of avocado seed extract (P2) group and the other groups (p<0.05). Conclusions: The administration of avocado seeds (Persea americana Mill.) extract cream 10% effectively inhibits the increase in MMP-12 enzyme levels and elastosis in hairless male Wistar rat skin which was exposed to ultraviolet A irradiation.

UVA

avocado seed extract

Persea americana Mill.

MMP-12

elastin fibers