Retinal structure and function preservation by polysaccharides of wolfberry in a mouse model of retinal degeneration

Retinitis pigmentosa (RP) is a heterogeneous group of inherited disorders caused by mutations in a variety of genes that are mostly expressed by rod cells, which results in initial death of rod photoreceptors followed by gradual death of cone photoreceptors. RP is currently untreatable and usually leads to partial or complete blindness. Here, we explored the potential neuroprotective effects of polysaccharides of wolfberry, which are long known to possess primary beneficial properties in the eyes, on photoreceptor apoptosis in the rd10 mouse model of RP. We found that these polysaccharides provided long-term morphological and functional preservation of photoreceptors and improved visual behaviors in rd10 mice. Moreover, we demonstrated that polysaccharides exerted neuroprotective effects through antioxidant, anti-inflammatory and anti-apoptotic mechanisms. Furthermore, we identified that polysaccharides modulated inflammation and apoptosis partly through inhibition of NF-κB and HIF-1α expressions, respectively. Overall, we demonstrated the synergistic protective effects of polysaccharides in preserving photoreceptors against degeneration in rd10 mice. Our study provides rationale and scientific support on using polysaccharides of wolfberry as one supplementary treatment of RP patients in the future.