The Photoprotective Effect of Cucurbita moschata Seed Extract on Rat Skin Exposed to Ultraviolet Radiation

Photoaging induced by ultraviolet B (UVB) radiation is characterized by DNA damage, oxidative stress, extracellular matrix degradation, and collagen loss. This study evaluated the photoprotective effects of topical pumpkin seed (Cucurbita moschata) extract cream against UVB-induced skin damage in Wistar rats. CPD (cyclobutane pyrimidine dimer), MDA (malondialdehyde), MMP-1 (matrix metalloproteinase-1) levels, and collagen density were assessed. UVB exposure significantly increased CPD, MDA, and MMP- 1 levels while reducing collagen density. Treatment with pumpkin seed extract cream, particularly at 10% concentration, markedly reduced CPD and MDA levels (P ≤ 0.05), indicating potent DNA repair support and antioxidant activity likely attributable to phenolic and flavonoid compounds. MMP-1 levels were significantly decreased, approaching normal values, suggesting inhibition of collagen degradation through anti-inflammatory and anti-matrix degradation mechanisms. Histological examination revealed higher collagen density and more organized collagen fibers in treated groups compared with negative control and placebo. These findings indicate that Cucurbita moschata seed extract cream exerts strong photoprotective, antioxidant, anti-inflammatory, and collagen-preserving effects, with the 10% formulation showing the greatest efficacy.