Topical application of phycocyanin accelerates wound healing in STZ-induced diabetic rats via activation of the Nrf2 signaling pathway.

The present study aimed to evaluate the wound healing potential of phycocyanin (PC) in diabetic rats. STZ (55 mg/kg) was injected intraperitoneally in Wistar rats for the induction of diabetes. A sterile biopsy punch created a foot ulcer (5 mm). Diabetic rats were treated with topical PC (1.5% and 2.5%) for 2 weeks. Body weight and metabolic parameters were measured. Various biochemical estimations, including oxidative stress markers (LPO, PCO), antioxidant indices (GSH, SOD), collagen content, and anti-inflammatory markers (IL-1β, TNF-α, NF-κβ, IL-6), along with MMP-9, VEGF, Nrf2, and HO-1 levels were assessed in the wound tissue. MTT and in-vitro scratch assays were also performed. The results revealed that significantly increased wound closure and collagen content but failed to alter the STZ-induced increase in metabolic parameters. Furthermore, PC suppressed oxidative stress pro-inflammatory markers and MMP-9 levels and enhanced anti-oxidant defences, VEGF, Nrf2, and HO-1 levels in the wound tissue. In addition, in vitro studies demonstrated a significant increase in cell migratory activity in the wound-healing scratch assay. Collectively, this study suggests that PC accelerated wound healing by reducing oxidative stress and inflammation, possibly via upregulation of the Nrf2 signaling pathway, making it an effective approach for treating diabetic foot ulcers.