Figure 3.

In vivo protection against P. aeruginosa and S. aureus. Ten mice groups were established to evaluate the antivirulence activity of sitagliptin at sub-MIC against P. aeruginosa and S. aureus. Five mice groups were intraperitoneally injected with untreated P. aeruginosa, DMSO-treated P. aeruginosa, sitagliptin-treated P. aeruginosa, or sterile PBS, and the last group was uninjected. The same grouping was used for evaluation against S. aureus: five mice groups were injected with untreated S. aureus, DMSO-treated S. aureus, sitagliptin-treated S. aureus, or sterile PBS or remained uninjected. The deaths among mice groups were recorded and plotted by Kaplan–Meier method, and log-rank test was employed to test the significance. (A) Protection against P. aeruginosa: sitagliptin protected all mice, in comparison to 3 deaths in the positive control groups that were injected with untreated P. aeruginosa, conferring 60% protection. (B) Protection against S. aureus: sitagliptin protected all mice, while two deaths were recorded in positive control groups that were injected with untreated S. aureus, conferring 40% protection. Sitagliptin showed significant reduction in the capacity of P. aeruginosa and S. aureus to kill mice; log-rank test p = 0.0028 and 0.0244, respectively. *: p ≤ 0.05, **: p ≤ 0.01.