The data was presented as the mean± standard error of mean
(SEM). The normality of all the data was first determined by
Kolmogorov–Smirnov test. Statistical differences were
determined using paired student’s t-test, or one-way analysis
of variance (ANOVA) followed by Tukey HSD post hoc test.
Data that were not normally distributed were analysed using
non-parametric tests, i.e. Wilcoxon-Signed-Rank test or
Kruskal–Wallis test. A value of p < 0.05 was considered to
be significant. All analyses were performed using SPSS
software version 20.0 (SPSS Inc., Chicago, USA).