In Sri Lankan ethnomedicate it is claimed the flowers of Nyctanthes arbo-tristis is effective in the treatment of inflammatory conditions but this has not been scientifically validated. This experiment was carried to investigate the antinflammatory potential of hot water infusion of Nyctanthes arbo-tristis flowers. Oral antiinflammatory activity of hot water infusion of Nyctanthes arbo-tristis flowers (concentrations: 3.75, 7.5, 12.5 and 18.75 mg/kg) was assessed in rats using both acute (carrageenan-induced paw oedema assay) and chronic (formaldehyde induced-paw oedema and cotton pellet-granuloma tests) inflammatory models. In an attempt to investigate its mode of action, antihistamine activity (by wheal test), inhibition of prostaglandin synthesis (by enteropooling test), inhibition of Tumor necrosis factorα secretion (using human mononuclear cells), and suppression of vascular permeability (acetic acid-induced vascular permeability test) and cytotoxicity (Evans blue test) were assessed. In the carrageenan-induced paw oedema test, hot water infusion simultaneously suppressed both initial and late stages of inflammation in an inversely dose related manner. Hot water infusion also inhibited paw oedema in formalin and cotton pellet granuloma tests. In addition, this infusion exhibited marked anti histamine activity, prostaglandin synthesis inhibition and suppression of vascular permeability. These findings scientifically support the traditional use of Nyctanthes arbo-tristis flowers in treatment of inflammatory conditions.
Keywords: Nyctanthes arbo-tristis flowers; antiinflammatory activity; hot water infusion; inflammation.