Lycium barbarum polysaccharide as a retinoprotective agent: A meta-analysis of preclinical evidence from rodent models of retinopathy

Lycium barbarum polysaccharides are considered the primary active ingredient of Lycium barbarum, and their therapeutic effects on retinal diseases have been extensively described. However, a systematic review and meta-analysis of these studies have not been conducted previously. This review aims to systematically review and meta-analyze published animal studies to investigate the mechanisms of the antioxidative, anti-inflammatory, anti-apoptotic, and neuroprotective effects of Lycium barbarum polysaccharides in rodent models of retinal diseases. To objectively and quantitatively compare the efficacy of Lycium barbarum polysaccharides in rodent models of retinal disease, a systematic review was conducted to search the PubMed and Web of Science databases (from inception to July 2024) for studies conducted in animals that met all a priori inclusion criteria. The included 27 studies reported outcomes on retinal structure (outer nuclear layer thickness) or function (electroretinogram b-wave amplitude). The methodological quality, assessed using the SYRCLE bias risk assessment tool, indicated that the overall risk of bias in the included literature was predominantly moderate. The results of the meta-analysis conducted using RevMan 5.4.1 software found that Lycium barbarum polysaccharides are protective against retinal injury in animal models, as evidenced by increases in the thickness of the outer nuclear layer and b-wave amplitude. The mechanisms involved include antioxidant effects, anti-inflammation, anti-apoptosis, and modulation of glia-driven neuroinflammation. Findings from this review confirm the protective actions of Lycium barbarum polysaccharides on retinal outer nuclear layer thickness and neuronal cells in rodent models of retinal diseases and may help propose strategies for future translational research on Lycium barbarum polysaccharides.