Protective Potential of Garcinia Cowa Roxb Fruit Peel Extract Against UVB-Induced Skin Damage in Rattus norvegicus Rats

Garcinia cowa (G. cowa) Roxb., a medicinal plant used in traditional medicine, possesses antioxidant properties and contains bioactive compounds like flavonoids and vitamin C. This study examined the impact of G. cowa extract from the fruit rind on skin thickness, the number of fibroblast cells, and collagen density in Rattus norvegicus rats exposed to UVB light. Thirty rats were divided into five groups (six each) in a post-test randomized control design. The negative control group (C-) was not exposed to UVB; the positive control group (C+) was exposed to UVB. Three treatment groups (T1, T2, and T3) were exposed to UVB and treated with 3%, 5%, and 8% extracts, respectively, on the back skin. The extract was prepared by macerating 1015 g of the fruit rind with 96% ethanol at a 1:5 ratio for 2 × 24 hours. The results of histopathological analysis revealed several significant changes in each group compared to the control group (C+). Epidermal thickness decreased in all treatment groups: T1 decreased by 37.58%, T2 decreased by 46.22%, and T3 showed the most significant decrease of 58.73%. In contrast, the number of fibroblasts increased in each group: T1 increased by 44.44%, T2 increased by 55.56%, and T3 increased by 102.22%. Similarly, collagen density increased in all treatment groups: T1 by 18.79%, T2 by 9.11%, and T3 by 10.83%. Garcinia cowa Roxb fruit peel extract effectively prevents epidermal thickening, protects fibroblast cells from damage, and slows down the loss of collagen density.