Collected skin specimens were carefully rinsed with ice-cooled saline, gently blotted between filter papers and weighed. Ten percent of homogenates were prepared in ice-cooled phosphate-buffered saline (PBS, 50 mM potassium phosphate, pH 7.4) followed by centrifugation at 10,000 g for 20 min at 4°C. The supernatant was used for the estimation of malondialdehyde (MDA), reduced glutathione (GSH) content, superoxide dismutase (SOD) activity and glutathione peroxidase (GPx) activity as antioxidant biomarkers. In addition, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and hydroxyproline concentrations were all assessed.