Camellia oleifera shells polyphenols inhibit advanced glycation end-products (AGEs) formation and AGEs-induced inflammatory response in RAW264.7 macrophages

Cammelia oleifera C.Abel (C. oleifera), a characteristic tropical economic crop, which is widely cultivated in Southern China. The fruit shells are a main by-product in the C. oleifera industry without high-value utilization. This work optimized the ultrasound-microwave synergistic extraction (UMSE) process of C. oleifera shells crude polyphenols (CSCP). The impacts of C. oleifera shells pure polyphenols (CSPP) on the advanced glycation end-products (AGEs) accumulation and AGEs-triggered inflammation were assessed. The results showed that the highest yield of CSCP reached 125.85 ± 5.34 mg extract/g dry shells under the optimum condition. Furthermore, CSPP exhibited intense anti-glycation action by scavenging free radicals and glycated intermediates, chelating transition metals, attenuating molecular aggregation, and conformational modification of BSA. Moreover, CSPP was found to dose-dependently block the AGEs-induced secretions of pro-inflammatory cytokines by inhibiting the downstream iNOS and COX-2 related MAPK/NF-κB pathway. These findings indicated that C. oleifera shells polyphenols could be a functional ingredient for preventing AGEs production and AGEs-induced inflammation.