Combined Mulberry Leaf and Fruit Extract Improved Early Stage of Cutaneous Wound Healing in High-Fat Diet-Induced Obese Mice

Obesity is a pandemic that causes many health challenges, including difficulties in achieving proper wound healing without complications. The current study investigated the role of NLRP3 inflammasome in the early stages of cutaneous wound healing and the effect of combined mulberry leaf and fruit extract (MLFE) on cutaneous NLRP inflammasome involvement in delayed wound healing mice with high-fat diet (HFD)-induced obesity. After obesity was induced by HFD for 10 weeks, the mice were supplemented with MLFE (at a dose of 500mg/kg containing 333.3mg/kg of mulberry leaf extract and 166.7mg/kg of mulberry fruit extract) by gavage, 5 days/week for 12 weeks. MLFE supplementation ameliorated delayed wound closure in obese mice. While wound size was positively correlated with fasting blood glucose level during the early stage of wound healing, it was strongly correlated with body weight gain and body fat mass during the later stage of wound healing. Under obese conditions, the levels of NLRP3 inflammasome and its related markers (pro-caspase-1 and precursor/mature interleukin 1 beta) were increased at a basal level, but the NLRP3 inflammasome was suppressed during the inflammatory stage of cutaneous wound healing. However, MLFE supplementation stimulated cutaneous NLRP3 inflammasome in HFD-induced obese mice (day 3). Taken together, stimulating the NLRP3 inflammasome might be beneficial in the early inflammatory stage of cutaneous wound healing and MLFE could be a potential therapeutic intervention in delayed wound healing through activation of the NLRP3 inflammasome in obesity.