Effects of NGR1 on the Protective Efficacy and Functional Vision Profile of Retinal Photodamage

Prolonged exposure to high-intensity light can harm macula vision, particularly affecting the function of Müller cells and cone photoreceptors. Panax notoginseng saponins (PNS) have valuable pharmacological effects on cerebrovascular, neurological, and microcirculatory health. Notoginsenoside R1 (NGR1), derived from PNS, shows potential for treating vascular or ischemia-reperfusion-related retinal issues; however, its impact on cone cells and the functional vision profile is not well understood. This study aimed to explore the effect and efficacy of NGR1 on retinal photodamage in vivo in mice. In a mouse model, high-intensity light causes significant photoreceptor damage, increases the production of pro-inflammatory factors, promotes Müller cell gliosis, and remarkably reduces the content of M- and S-opsin in cones, resulting in the abnormal and dysfunctional mislocalization of cone-opsin protein trafficking. Our data demonstrated that NGR1 orally administered improved ERG amplitude, visual acuity, and visual contrast sensitivity function compared to the vehicle group. It also preserved S- and M-cone density, mitigated abnormal trafficking of cone opsin protein, inhibited Müller cell gliosis, and reduced retinal inflammation. Therefore, NGR1 may serve as a valuable traditional complementary therapeutic or nutraceutical component for enhancing functional vision and supporting the health of Müller and cone cells in the macula.