Pain modulation by curcumin and ascorbic acid in mice

The present study aims to evaluate whether ascorbic acid (AA) and curcumin, two substances with redox properties, have similar effects on different models of pain in mice.

This study included a total of 28 mice that were divided into four groups. One group (AA) received intraperitoneally 500 mg/kg b.w. AA for 21 days and the 2-nd group (curcumin) received 120 mg/kg b.w. curcumin by gastric gavage for two weeks. Other two groups serve as control and received vehicle in a dose--time manner similar to that of the treated groups. The pain models (oro-facial formalin induced pain, paw formalin induced pain and visceral pain) were performed 24 h after the last dose.

When compared with control groups, curcumin significantly decreases pain perception in oro-facial (p = 0.01 1-st phase, p = 0.002 2-nd phase) and paw formalin induced pain (p = 0.04 1-st and 2-nd phase) while AA stimulates pain perception in acid acetic induced visceral pain (p = 0.05) and increases oro-facial inflammatory pain induced by formalin ( p = 0.02) but demonstrates analgesic effects on paw formalin induced pain (p = 0.003 1-st phase, p = 0.01 2-nd phase).

ROS production is important in pain modulation. Structures involved in the process of pain have different antioxidant defense capacities. Curcumin and AA are able to modulate pain perception, but beside their antioxidant capacities, there are other mechanisms involved.