Cici R. Ustika, Sri Priyantini, Agung Putra, Prasetyowati Subchan, Titiek Sumarawati, Nur D. Amalina
Prolonged exposure to high-intensity UVB radiation can induce the formation of Reactive Oxygen Species (ROS), inhibit alpha-smooth muscle actin (α-SMA), and collagen type 1 expression, leading to skin hyperpigmentation. This study aimed to investigate the effect of topical application of stink bean peel extract gel on the expression of α-SMA and collagen type 1 genes in the skin tissue of hyperpigmentation rats. Stink bean peel extract gel was prepared by mixing ethanol extract of stink bean peel with a gel base (Catechu) to make 10% and 20% formulations. Hyperpigmentation was induced in rats by exposure to UVB radiation (λ302 nm, 390 mj/cm2/day) three times a week for two weeks. The animals were divided into four groups: K1 (healthy rats), K2 (negative control), K3 (10% extract gel, and K4 (20% extract gel). The effect of stink bean peel extract gel treatment on the expression of α-SMA and collagen type 1 genes was analyzed using Real-Time Quantitative Reverse Transcription polymerase chain reaction (qRT-PCR). qRT-PCR analysis indicated a significant (p < 0.05) increase in the expression of α-SMA gene in group K4 with a mean expression ratio of 3.11±1.08 compared to the negative control (0.67±0.17). Collagen type 1 gene expression also increased significantly in K3 and K4 groups with expression ratios of 2.21±0.68, and 2.12±0.73, respectively compared to the negative control (0.51±0.14). Findings from this study has shown that stink bean peel extract has the potential to be used as a protective and therapeutic agent against UVB-induced skin damage. © 2025 Ustika et al and 2025 the authors.
Department of Biomedical Sciences, Faculty of Medicine, Universitas Islam Sultan Agung, Semarang, 50112, Indonesia; Departement of Pathology, Faculty of Medicine, Universitas Islam Sultan Agung, Semarang, 50112, Indonesia; Stem Cell and Cancer Research Indonesia, Semarang, 50112, Indonesia; Pharmaceutical Sciences Department, Faculty of Medicine, Universitas Negeri Semarang, Semarang, 50229, Indonesia
