Statistical Analysis
Statistical analysis was completed using IBM SPSS 23.0 (SPSS for Windows, SPSS Inc., Chicago, IL, USA). The Shapiro–Wilks test was used for normality testing of native thiol, total thiol, disulphide level, disulphide/native thiol, disulphide/total thiol, and native thiol/total thiol ratios. The groups displayed normal distribution. The independent samples t‑test, among parametric tests, was used to investigate whether there were considerable differences between the groups. P < 0.05 was accepted as statistically significant.