Antinociceptive Activity of Petroleum Ether Fraction of Clinacanthus nutans Leaves Methanolic Extract: Roles of Nonopioid Pain Modulatory Systems and Potassium Channels

Figure 5

The involvement of various nonopioid receptor antagonists on PECN–induced antinociception in the acetic acid–induced abdominal writhing test in mice. Pindolol (PDL; 1 mg/kg, i.p.), yohimbine (YOH; 0.15 mg/kg, i.p.), Haloperidol (HAL; 0.2 mg/kg; i.p.), caffeine (CAF; 3 mg/kg, i.p.), or atropine (10 mg/kg, i.p.) was administrated 15 min before vehicle (10 mL/kg, p.o.) or PECN (500 mg/kg, p.o.). Each column represents the mean ± SD of six mice. Statistical analyses were performed using 1–way ANOVA followed by Bonferroni’s post hoc test. < 0.001 significantly differed when compared to control group. < 0.001 significantly differed when compared to 500 mg/kg PECN–treated group.