Polysaccharides from Annona muricata leaves protect normal human epidermal keratinocytes and mice skin from radiation-induced injuries

Radiation-induced skin injuries are a common side effect of radiotherapy. Plant-derived polysaccharide is considered as an attractive cosmeceutical ingredient for skin damage therapy. This study was conducted to investigate the protective effects of Annona muricata leaf polysaccharide (ALP) on radiation-induced skin injuries by using in vitro and in vivo models. In normal human epidermal keratinocytes (NHEKs), ALP treatments reduced irradiation-induced apoptosis by increasing antioxidant enzymes activities, including superoxide dismutase (SOD) and catalase. Furthermore, ALP treatments decreased levels of interleukin-1 beta, nucleotide-binding domain and leucine-rich-repeat-containing family pyrin 3 (NLRP3), and cleavage of caspase-1 and caspase-3. Most importantly, the topical application of the ALP cream showed protective efficacy against irradiation exposure, including the reduction of epidermal thickening, as well as an increase in the number of apoptotic cells and antioxidant enzyme (SOD and catalase) activities in skin tissue. Our results indicate that ALP can be potentially used to treat radiation-induced skin injuries.