Figure 1.
Time-related effects of CFA injection into the mouse paw.
Effect of intraplantar injection of CFA (50 μl/paw) 1, 2, 3 and 4 weeks: (A) Paw edema analyzed in a plesthysmometer (difference between the right and the left paws), (B) immobility time in tail suspension test (TST), and (C) locomotor activity in the open-field test, (D) changes of body weight (Δ grams), (E) AUC of body weight, 0 to 7 days post-CFA injection, (F) AUC of body weight, 8 to 14 days post-CFA injection, (G) variation of body temperature, after injection of CFA (Δ °C), (H) AUC of body temperature 0 to 7 days post-CFA injection and (I) AUC of body temperature 8 to 14 days post-CFA injection. Each point or column represents the mean ± SEM of 6-8 animals per group. *P < 0.05 and **P < 0.01 significantly different from Saline+Saline group (ANOVA followed by Bonferroni’s post-hoc test).
Figure 2.
Evaluation of anti-inflammatory and antidepressants drugs in depressive-like behaviour and paw edema induced by CFA.
Effect of intraplantar injection of CFA (50 μl/paw) at 2 weeks. (A and C) Paw edema analyzed in a plesthysmometer (difference between the right and the left paws), and (B and D) immobility time in tail suspension test (TST). Effect of treatment with imipramine, fluoxetine and bupropion (10 mg/kg, 20 mg/kgand 30 mg/kg, p.o, once a day, 7 days; respectively) or dexamethasone, indomethacin and celecoxib (0.5 mg/kg, s.c., 10 mg/kg, p.o. and 30 mg/kg, p.o., once a day, for 7 days, respectively). Independent groups were used to analyse the effects of anti-inflammatory or antidepressant drugs on paw edema or depression-like behavior. Each column represents mean ± SEM of 6-8 animals per group. *P < 0.05 and **P < 0.01 significantly different from Saline+Saline group; # P < 0.05 and # # P < 0.01 significantly different from CFA+Saline group (ANOVA followed by Bonferroni’s post-hoc test).
Figure 3.
Assessment of pregabalin and dipyrone effects on the mechanical allodynia, paw edema and depressive-like behaviour induced by CFA.
Effect of intraplantar injection of CFA (50 μl/paw) at 2 weeks. (A) Mechanical paw withdraw threshold analyzed by using the von Frey test; (B) Paw edema analyzed in a plesthysmometer (difference between the right and the left paws); and (C) immobility time in the tail suspension test (TST). Effects of treatment with dipyrone (30 and 300 mg/kg, p.o., once a day, during 7 days) or pregabalin (30 mg/kg, p.o., once a day, for 7 days). Each column represents the mean ± SEM of 6 to 8 animals per group. *P < 0.05 and **P < 0.01 significantly different from saline + saline group, and # P < 0.05 and # # P < 0.01 significantly different from CFA + saline group (ANOVA followed by Bonferroni’s post-hoc test).
Figure 4.
Dose-response analysis for the anti-inflammatory and antidepressant activities of celecoxib and bupropion.
Effect of intraplantar injection of CFA (50 μl/paw) at 2 weeks. (A and C) Paw edema analyzed in a plesthysmometer (difference between the right and the left paws), and (B and D) immobility time in tail suspension test (TST). Dose-response effect of bupropion (3, 15 and 30 mg/kg, p.o., once a day, 7 days) or celecoxib (3, 15 and 30 mg/kg, p.o., once a day, 7 days). Independent groups were used to analyse the effects of anti-inflammatory or antidepressant drugs on paw edema or depression-like behavior. Each column represents the mean ± SEM of 6-8 animals per grup. **P < 0.01 significantly different from Saline+Saline group, # P < 0.05 and # # P < 0.01 significantly different from CFA+Saline gropu (ANOVA followed by Bonferroni’s post-hoc test).
Figure 5.
Effects of combined treatment with bupropion and celecoxib on CFA-induced inflammation and depression.
Effect of intraplantar injection of CFA (50 μl/paw) at 2 weeks. (A) Paw edema analyzed in a plesthysmometer(difference between the right and the left paws), (B) immobility time in tail suspension test (TST), and (C) immobility time in forced swimming test (FST). Synergistic effect between different classes of drugs: bupropion and celecoxib both at (3 mg/kg, p.o., once a day, 7 days) and effect of treatment with imipramine (10 mg/kg, p.o., once a day, 7 days). Each column represents the mean ± SEM of 6-8 animals per group. **P < 0.01 significantly different from Saline+Saline group, # P < 0.05 and # # P < 0.01 significantly different from CFA+Saline group (ANOVA followed by Bonferroni’s post-hoc test).
Figure 6.
Determination of IL-1β, and BDNF levels in the brain of CFA-treated mice: effects of treatment with bupropion and celecoxib.
Effect of intraplantar injection of CFA (50 μl/paw) at 2 weeks: IL-1β levels in the (A) whole brain, (B) cortex and (C) hippocampus. Effect of treatment with celecoxib and bupropion both at (30 mg/kg, p.o, once a day, 7 days) and combined effect of bupropion plus celecoxib (3 mg/kg, p.o, once a day, 7 days). (D) BDNF levels in cortex. Effects of treatment with celecoxib and bupropion (both at 30 mg/kg, p.o, once a day, 7 days) and combination of bupropion and celecoxib (both at 3 mg/kg, p.o, once a day, 7 days). Each column represents the mean ± SEM of 4 animals per group. **P < 0.01 significantly different from Saline+Saline group, # P < 0.05 and # # P < 0.01 significantly different from CFA+Saline group (ANOVA followed by Bonferroni’s post-hoc test).
Figure 7.
Immunolabelling for COX-2 in the cortex brain of CFA-treated mice: effects of treatment with bupropion and celecoxib.
Immunohistochemistry analysis for COX-2 after intraplantar injection of CFA (50 μl/paw) at 2 weeks. Arrowheads (▲) indicate positive immunostaining for COX-2. Representative images of immunohistochemistry analysis for COX-2 in the mouse brain cortex: (A) schematic representation of the mouse brain indicating the region used for quantification (C) Control saline + saline group, (D) CFA + saline, (E) CFA + celecoxib (30 mg/kg, p.o., once a day, 7 days; respectively), (F) CFA + bupropion (30 mg/kg, p.o., once a day, 7 days; respectively), (G) CFA + bupropion and celecoxib (3 mg/kg, p.o., once a day, 7 days; both drugs). (B) Graphic showing the semi-quantitative analysis of immunostaining for COX-2. Scale bar represents 10,000 µm. Each column represents the mean ± SEM of 4 animals per group. **P < 0.01 significantly different from Saline+Saline group, # P < 0.05 significantly different from CFA+Saline group (ANOVA followed by Bonferroni’s post-hoc test).