2.5. Statistical analysis
The results of this study are presented as the mean values accompanied with their standard deviations of at least four independent experiments. One factor analysis of variance (ANOVA) was performed. Differences between means were considered statistically significant at p b 0.05. The software which was used for the statistical analysis was Statgraphics Centurion XVI, Version 16.1.17, (Warrenton, Virginia, USA).