Effects of an essential oil from the bark of Croton cajucara benth. on experimental gastric ulcer models in rats and mice

Croton cajucara Benth. (Euphorbiaceae) is widely used in Amazonian folk med icine for the treatment of a wide range of gastrointestinal symptoms. The e ssential oil from its bark was investigated for acute toxicity in mice and for its ability to prevent the formation of ulceration of the gastric mucos a in different models of experimentally induced gastric ulcer in mice and r ats. When previously administered orally at a dose of 100 mg kg(-1), the essenti al oil significantly reduced (P < 0.01) the gastric injury induced by hypot hermic restraint stress (48%), indomethacin (47%), ethanol (86%) and pyloru s ligature models (87%) in rats. In the HCl/ethanol-induced gastric ulcer m odel in mice, at oral doses of 100 and 200 mg kg(-1), the essential oil fro m C. cajucara significantly reduced (P < 0.01) the formation of gastric les ions by 52% and 67%, respectively, when compared with the control group. In rats submitted to pylorus ligature, the essential oil given orally increas ed the volume of gastric juice when compared with the control group (P < 0. 01). When the essential oil (100 mg kg(-1)) was administered intraduodenall y to mice, significant modifications were found in gastric parameters such as pH and total acid content after oil treatment. We observed significant c hanges (P < 0.01) in gastric juice parameters such as an increase in volume and a decrease in gastric acidity (pH and total acid content). The acute t oxicologic effects of the essential oil from C. cajucara were assessed in m ice. The LD50 values were 9.3 g kg(-1) by the oral route and 680 mg kg(-1) by the intraperitoneal route. The good yield of essential oil obtained from dried C. cajucara bark (1%) a s well as its anti-ulcerogenic activity and low toxicity suggest that pharm acological studies of this substance as a potential new anti-ulcerogenic dr ug are warranted.