Anti-Inflammatory Effect and Skin Toxicity of Aqueous Extract of Dorema ammoniacum Gum in Experimental Animals

Dorema ammoniacum gum resin is used in Iranian traditional medicine for different indications including inflammatory diseases which are on the rise. Considering the important role of inflammation in different diseases, in the present study, we aimed to investigate the in vivo anti-inflammatory activity and skin toxicity of Dorema ammoniacum gum extract (DAGE) in rats and rabbits.

The systemic anti-inflammatory effect ofDAGE (100, 200 and 300 mg/kg, i.p.) was assessed by carrageenan-induced paw edema method in 30 min, 1, 2, 3 and 4 h after the carrageenan injection to thirty male Wistar rats divided into five groups of six each. Control and standard groups received the vehicle and mefenamic acid (30 mg/kg, i.p.), respectively. To assess the topical anti-inflammatory effect ofthegum, eighteen rats were divided into three groups of six: standard, vehicle, and test groups which received topical diclofenac gel, distilled water and DAGE, respectively. The acute dermal toxicity of DAGEwas evaluated in nine white New Zealand rabbits.

The results showed significant anti-inflammatory effects of DAGE in systemic treatment.The findings also indicated that all doses of DAGE were more potent than mefenamic acid. However, the topical anti-inflammatory activity of DAGE (100 mg/kg) was comparable to that of diclofenac gel 2% and showed no skin toxicity.

The results of the present study suggest that DAGE has significant anti-inflammatory effects without any erythema and edema in topical use. These effects might be partially or wholly due to possible inhibition of or interference with the production of some inflammatory mediators, especially prostaglandins, histamine, serotonin, and bradykinin.