Statistical analysis
All values are expressed as mean ± S.E.M. One-way ANOVA, followed by Dunnett’s test, or Student’s unpaired t -test were used to evaluate differences between three or more groups or between two groups, respectively. Mac statistical analysis Ver.3.0 software (Esumi Co., Ltd., Tokyo, Japan) was used for the statistical analyses. Differences were considered to be significant when P < 0.05.