Some pharmacological studies on the methanolic extract of <i>Inula graveolense</i> L.

Abstract

Inula graveolens L. is widely used in Iraq for the treatment of rheumatic fever, infant convulsions, toothache, blood sugar, and also to dissolve internal blood clots, and to aid digestion. However, the efficacy and mechanisms of action of the plant remain unclear. Therefore, the objective of the present study was to investigate the pharmacological effects of the methanolic extract (MEIG) of this plant belonging to compositae family. Anti-diarrheal and antipyretic activities of the extract were examined in rats. Anti-inflammatory and antinociceptive were studied in mice. At the doses of 200 (P < 0.05) and 400 mg/kg body weight (P < 0.01), the extract displayed remarkable anti-diarrheal activity, evidence by a reduction in the rate of defecation as well as by retardation of intestinal transit of charcoal meal compared to normal saline control group, dose dependently similar to loperamide (5 mg/kg). The methanolic extract (400 mg/kg) showed a significant (P < 0.01) dose dependent anti-pyretic effect in yeast induced elevation of body temperature in experimental rats. The methanolic extract showed significant anti-inflammatory and antinociceptive activity at the dose of 400 mg/kg (P < 0.01) as compared to standard drug diclofenac sodium (50 mg/kg). The extract inhibited paw and ear edema in a dose-related manner. A dose-dependent analgesic action was obtained against chemical (writhing test) and thermal (hot-plate test) stimuli indicated that antinociceptive activity may involve inhibition of pain by peripheral and central mechanisms. Again, the methanolic extract (MEIG) was subjected for in vitro protein anti-denaturation using Bovine serum albumin and anti-platelet aggregation of human blood activity. It was observed that the extract showed greater percentage of inhibition of BSA (P < 0.01) at the highest concentration (400 μg/ml). The extract also showed potential platelet aggregation inhibitory activity in adose-dependent manner. The maximum inhibition was observed at the dose 400 μg/ml (P < 0.01) compared to standard drug commercial heparin (20 μg/ml).