Fig. 4: Alleviation of CFA-induced inflammatory and SNI-induced neuropathic pain via exendin 9–39 administration.

a Schematic illustration and timeline of the CFA-induced inflammatory chronic pain model in mice. b Effects of intraplantar injection of exendin 9–39 (Exe 9–39) (5 and 10 μg) on thermal hyperalgesia in a CFA-induced inflammatory chronic pain mouse model via the Hargreaves test (mean ± S.E.M., n = 7 each). Two-way ANOVA followed by the Bonferroni multiple comparison test (****p < 0.0001, compared with the CFA group). c Effects of intraplantar injection of exendin 9–39 (Exe 9–39) (5 and 10 μg) on mechanical allodynia in a CFA-induced inflammatory chronic pain mouse model via the von Frey test (mean ± S.E.M., n = 7 each). Two-way ANOVA followed by the Bonferroni multiple comparison test (*p < 0.05, **p < 0.01, ***p < 0.001, compared with the CFA group). d Schematic illustration and timeline of the SNI-induced chronic neuropathic pain model in mice. e Effects of intraplantar injection of exendin 9–39 (Exe 9–39) (10 μg) on thermal hyperalgesia in an SNI-induced chronic neuropathic pain mouse model via the Hargreaves test (mean ± S.E.M., n = 7 each). Two-way ANOVA followed by the Bonferroni multiple comparison test (*p < 0.05, **p < 0.01, compared with the Sham + Vehicle group; ^####p < 0.0001, compared with the SNI + Vehicle group). f Effects of intraperitoneal injection of exendin 9–39 (Exe 9–39) (10 μg) on thermal hyperalgesia in an SNI-induced chronic neuropathic pain mouse model via the Hargreaves test (mean ± S.E.M., n = 7 each). Two-way ANOVA followed by the Bonferroni multiple comparison test (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, compared with the Sham + Vehicle group; ^#p < 0.05, ^##p < 0.01, compared with the SNI + Vehicle group). ANOVA analysis of variance, CFA complete Freund’s adjuvant, SNI spared nerve injury, GLP-1 glucagon-like peptide-1, S.E.M. standard error of the mean, TRPV1 transient receptor potential vanilloid 1.