RESUMO
In the present study, hydroalcoholic extract of the aerial parts of Origanum majorana was prepared. Two oral dose levels [100 and 200 mg/Kg] were evaluated for the analgesic activity [using the hot plate test], the anti-inflammatory effect [using carrageenan-induced paw oedema test] and the antipyretic activity [on yeast-induced hyperthermia] in albino rats. Results revealed that in the hot plate test, O. majorana extract exerted a highly significant analgesic effect in a dose dependant manner similar to that obtained by paracetamol. The extract also reduced paw-oedema caused by carrageenan, this result was more obvious in rats treated with 200 mg/Kg. The tested extract in the two doses used exerted an antipyretic effect after 30 min of administration. More interesting results were observed in the group treated with 200 mg/Kg, in which their temperature was reduced significantly more than in paracetamol-treated group during 1 -2 hr post-drug administration. O. majorana extract also exerted a hepatoprotective effect in carbon tetrachloride liver -damaged rats. Both doses [100 and 200 mg /Kg] significantly reduced the elevated values of liver function tests [GGT, ALT and AST], triglycerides [TGs], and cholesterol. Kidney function tests [creatinine and urea] were also decreased significantly. O. majorana had an immuno-stimulating property, as it increased IgG levels in normal and liver damaged rats. It is concluded that Origanum majorana had many pharmacological activities including a novel immunostimulant effect, which warrants further detailed investigations