Evaluation of the Biological Effects of Lyophilized Hydrophilic Extract of Rhus coriaria on Myeloperoxidase (MPO) Activity, Wound Healing, and Microbial Infections of Skin Wound Tissues

Impaired wound healing was mainly associated with severe microbial infections which significantly affect diagnostic and therapeutic strategies. Thus, in this study, the potential wound healing activity, anti-inflammatory, and antimicrobial activity of an aqueous extract of Rhus coriaria extract (AERc) were evaluated by wound contraction, scar formation, period of epithelization, MPO enzyme activity, collagenase-2 (MMP-8), hydroxyproline (HPX), and collagen deposition as markers of wound healing at different days of postwound. Phytoconstituents, microbial activity, and fibrogenic markers were screened by HPLC, disc-diffusion, and colorimetric assays. The animals were treated with Rhus coriaria extract (AERc) concentrations at doses of 5 mg.kg(-1)and 10 mg.kg(-1), respectively. On days 6 and 9, the AERc-treated animals at doses of 5 mg.mL(-1) and 10 mg.mL(-1) exhibited a significant reduction in the wound area, increased deposition of collagen, HPX, and reduction in MMP-8, and MPO enzyme activity when compared with controls. Scar formation and epithelization were completed in 10 days compared to controls. In addition, in wounds infected separately with Staph. aureus or P. aeruginosa, the AERc extract significantly improved wound contraction, deposition of collagen, and HPx and reduced MMP-8 and MPO concentrations, with complete epithelization of wounds in 10-13 days compared to the saline-treated group. Hydrolyzable tannins, gallic acid, quercetin, and myricetin were the most common active components of AERc. In vitro, the AERc and its components were effective against a set of microbes especially Staph. aureus, P. aeruginosa, and Staph. aureus (MRSA). In conclusion, the results showed that antimicrobial, anti-inflammatory, and antioxidant activity of Rhus coriaria extract suggested its importance as a target for formulation of novel drugs against many microbial infections with minimal side effects and could play a good potential role in accelerating wound healing activity via promoting myofibroblast activity, increase of hydroxyproline and collagen deposition, and regulation of MMP-8 and MPO enzyme activities.