Effect of Paris polyphylla extract on second-degree burns in rats

Purpose: To investigate the healing effect of Paris polyphylla extract (PPE) on second-degree burns in rats.Methods: Male Sprague Dawley (SD) rats, weighing 200 – 220 g, were subjected to deep seconddegree skin burns by electrical scald instrument. The animals were divided into three groups as follows: (1) second-degree burn model (control) group, (2) burn model treated with 1 % silver sulfadiazine (SSD) group, and (3) burn model treated with 120 mg·mL-1 PPE group. On days 3, 7 and 14 following the administration of the drug/extract, wound area and histopathological changes in rat epidermis were evaluated for the three groups. The minimum inhibitory concentration (MIC) of PPE on Staphyloccocus aureus, Pseudomonas aeruginosa and Escherichia coli were also assessed.Results: On day 14, the mean wound area of PPE treatment group (0.21 ± 0.04 cm2) was significantly smaller than that of the control rats (2.78 ± 0.18 cm2, p < 0.01). Histological results indicate that inflammatory cells disappeared and were replaced by new granulation tissue in the group treated with 120 mg·mL-1 PPE by day 14. Compared with SSD group rats, the inflammatory cells and fibroblast and granulation tissues of burnt rats with burns and treated with 120 mg·mL-1 PPE decreased significantly. The antibacterial data revealed that the MIC of PPE against S. aureus, P. aeruginosa and E. coli was 2.35, 8.2 and 4.70 mg·mL-1, respectively.Conclusion: Paris polyphylla is an effective medicinal herb that holds promise for the treatment of second-degree burns.Keywords: Paris polyphylla, Second-degree burns, Wound healing, Antibacterial, Inflammatory cells, Granulation tissues, Silver sulfadiazin