Modulation Effects on Acute Orofacial Inflammatory Pain in Rats by Curcuma longa L., Curcuma aromatica Salisb., Zingiber officinale Rosc. Extracts

Curcuma longa L. (C.L), Curcuma aromatica Salisb. (C.A) and Zingiber officinale Rosc. (Z.O) of Zingiberaceae plants which are well known as effects of natural anti-oxidant, anti-cancer and anti-inflammatory. We examined that the Zingiberaceae plants are involved in development and modulation of orofacial pain in rats. Male, 7- to 8-week-old, Sprague-Dawley rats weighing 240~280 g were used in this study. Experiments were performed using acute pain model that was caused by the injection of 5% formalin into the right vibrissa pad. The number of scratching or rubbing to the injection site was recorded for 9 consecutive 5-minute intervals following injection of formalin. The experimental groups were acute orofacial inflammatory pain; control group (formalin, 5%), vehicle group (5% formalin after sodium carboxymethyl cellulose), single administration group, single mixed administration group, repeated administration group. The experiments were performed various concentrations of Zingiberaceae plants extract. Therefore, oral administration of C.L, C.A, and Z.O (p.o., concentrations of 12.5, 25 mg/mL) in orofacial inflammatory pain model substantially decrease the nociceptive behavior in a concentration dependent manner. And it tended to decrease at low concentration (12.5 mg/mL) of single mixed and repeated administration more than single administration. This result means that Zingiberaceae plants extract affects the modulation of acute orofacial inflammatory pain. Thus, Zingiberaceae plants extract may be a potential therapeutic treatment for orofacial inflammatory pain.