Rubus suavissimus S. Lee Extract Alleviates Oxidative Stress and Inflammation in H2O2-Treated Retinal Pigment Epithelial Cells and in High-Fat Diet-Fed Mouse Retinas

Background: Age-related macular degeneration (AMD) is the most common cause of visual disorders in the aged population and is characterized by the formation of retinal pigment epithelium (RPE) deposits and dysfunction/death of the RPE and photoreceptors. It is supposed that both oxidative stress and inflammation play a critical role in the pathogenesis of AMD. The development of therapeutic strategies against oxidative stress and inflammation in AMD is urgently needed. Rubus suavissimus S. Lee (RS), a medicinal plant growing in the southwest region of China, has been used as an herbal tea and medicine for various diseases. Methods: In this project, we evaluate the therapeutic potential of RS extract for AMD. We prepared RS extracts from dried leaves, which contained the main functional compounds. Results: RS extract significantly increased cell viability, upregulated the expression of antioxidant genes, lowered the generation of malondialdehyde and reactive oxygen species, and suppressed inflammation in H2O2-treated human RPE cells. In the in vivo study, treatment with RS extract attenuated body weight gain, lowered cholesterol and triglyceride levels in the liver and serum, increased antioxidant capacity, and alleviated inflammation in the retina and RPE/choroid of mice fed a high-fat diet. Conclusions: Our findings suggest that RS extract offers therapeutic potential for treating AMD patients.