Pemberian Oral Ekstrak Kulit Buah Lemon (Citrus Limon) Menghambat Peningkatan Ekspresi MMP-1( matrix metaloproteinnase-1) dan Penurunan Jumlah Kolagen Pada Tikus Putih Galur Wiostar Jantan (Rattus Norvegicus) yang dipajan sinar UV-B

Ultraviolet B (UVB) is a source of free radicals that accelerate aging process of the skin such as activating enzymes that degrade collagen and inhibit collagen production by inducing the expression of MMP-1. Lemon peel contains vitamin C, vitamin A, tannins and phenols which possess antioxidant activity and prevent oxidative stress. This study was aimed to prove that oral administration of lemon peel extract could decrease MMP-1 levels and increase the number of collagen in the UVB-induced male Wistar rats (Rattus norvegicus). This was a true experimental study with the post test only control group design. Subjects were 30 male Wistar rats (Rattus norvegicus), aged 2-3 months, body weight 120 g, divided into 3 groups, as follows: the control group (P0) which were not exposed to UVB; the treatment group 1 (P1) given aquabidest and UVB ray exposure; and the treatment group 2 (P2) given lemon peel extract and UVB ray exposure. After 15 days of treatment, all rats were anesthetized and their skin tissues were prepared for histological examination of MMP1 and collagen. The results showed that the average expression of MMP1 in P0 group was 22.02±3.20%; in the P1 group was 29.04±6.36%; and in P2 group was 7.98±2.76% (P <0.01). In addition, the average amount of collagen in P0 group was 70.01±2.99%; in the P1 group was 57.68±4.84%; and in P2 group was 77.45±4.29% (P <0.01). Conclusion: Oral administration of lemon peel extract could decrease the expression of MMP-1 and increase the amount of collagen in the UVB-induced male Wistar rats (Rattus norvegicus). Keywords: lemon peels, collagen, MMP-1, UVB Abstrak: Ultraviolet B (UVB) merupakan sumber radikal bebas yang mempercepat proses