The antinociceptive effects of folic acid using formalin and acetic acid tests in male mice

Background and aims: Antidepressant agents such as imipramine are clinically used to control and treat different types of pain, especiallyneuropathic pain. Studies have shown the antidepressant-like activity of folic acid (FA). This study aimed to investigate the potentialantinociceptive effects of FA using formalin and acetic acid tests in male mice.Methods: Sixty male albino mice (۲۰-۳۰ g) were randomly divided into ۱۰ groups (n=۶ in each group) of negative control, positive control(morphine or indomethacin), and FA (۱۰, ۱۵, and ۳۰ mg/kg) groups. In the formalin test, duration of paw licking and biting the right hindpaw during acute (۰-۵ minutes) and chronic (۱۵-۶۰ minutes) pain after intraplantar injection of formalin ۲.۵% (۲۵ μL) was recorded. In thewrithing test, the abdominal constrictions were recorded after the intraperitoneal injection of acetic acid ۱%.Results: Only a high dose (۳۰ mg/kg) of FA significantly reduced acute pain (P = ۰.۰۰۱) compared with the control group. But all dosesof FA significantly decreased chronic pain (P = ۰.۰۰۱). In addition, morphine significantly reduced both phases of pain (P = ۰.۰۲۰ andP = ۰.۰۰۱, respectively). Moreover, indomethacin and all doses of FA decreased the number of abdominal constrictions induced by aceticacid (P = ۰.۰۰۱).Conclusion: Compared with acute (neurogenic) pain, FA more potently decreases chronic (inflammatory) pain. Furthermore, FA decreasesthe parietal pain that could potentially represent antinociceptive effect. However, further studies are needed to elucidate the exactmechanism of FA’s analgesic activity.

کلیدواژه ها:

Folic acid ، Antinociceptive ، Antidepressants ، Formalin test ، Writhing test ، Mice