CBS inhibitor AOAA attenuated AWR scores in NMD rats. (A) CBS inhibitor abolished visceral hyperalgesia induced by NMD in a dose dependent manner. The maximal effect was at 10 mg/kg body weight (i.p.) in this study. n=8 rats for each dose group; *P<0.05. (B) CBS inhibitor mitigated visceral hyperalgesia induced by NMD time-dependently. AOAA-induced antinociceptive effect lasted for about 60 minutes in both 10 and 20 mg/kg body weight. n=8 rats for each group; *P<0.05. (C) AOAA (10 mg/kg body weight) had no effect on AWR scores of age-matched healthy control rats (n=8).