Anti-inflammatory, antinociceptive and antioxidant activities of the endemic Soqotraen Boswellia elongata Balf. f. and Jatropha unicostata Balf. f. in different experimental models

In the present study, the two endemic Soqotraen plants Boswellia elongata and Jatropha unicostata were investigated for their anti-inflammatory, antinociceptive and antioxidant potential. To assess the anti-inflammatory and antinociceptive activities, two concentrations of each extract (200 and 400 mg/kg, p.o.) were tested in carrageenan-induced rat paw edema, cotton pellet granuloma in rats, acetic acid-induced abdominal writhing and hot-plate test model in mice. Moreover, the antioxidant activity was determined in vitro, using scavenging activity of DPPH radical and β-carotene-linoleic acid assays. Both plants produced significant (P < 0.05-0.01) anti-inflammatory and antinociceptive effects; however the results suggest that B. elongata possesses the highest activities. B. elongata and J. unicostata at (400 mg/kg) reduced the paw edema considerably (82% and 53%) and the weight of cotton pellet granuloma (51% and 32%), respectively. Furthermore, they diminished the abdominal constriction induced by acetic acid with a 67% and 41% inhibition respectively, and prolonged significantly the reaction time of animal with relatively extended duration of stimulation. In addition, both plants showed considerable antioxidant activity in both assays. These results clearly confirmed the traditional anti-inflammatory indication of B. elongata and suggest that B. elongata could be a potential source for anti-inflammatory, antinociceptive and antioxidant agents.