Anti-inflammatory activity of aqueous fruit pulp extract of Hunteria umbellata K. Schum in acute and chronic inflammation.

The anti-inflammatory effect of the aqueous fruit pulp extract of Hunteria umbellata K. Schum (Apocynaceae) was evaluated using the carrageenan- and dextran-induced rat paw edema, xylene-induced ear edema and formalin-induced arthritis inflammation tests. Oral administration of the extract produced significant (p < 0.05) antiedematogenic effect with a dose of 500 mg/kg throughout the period of the experiment in the dextran induced paw edema and at the 3 h in the carrageenan model. The extract (250 and 500 mg/kg) exhibited a dose-related and significant (p < 0.01) inhibition of xylene induced ear edema and the effect was similar to that produced by dexamethasone (1 mg/kg). In the chronic inflammation (formalin induced arthritis) the extract did not show any significant anti-inflammatory activity. Oral acute toxicity assays did not show any mortality at 15 g/kg of the plant extract. The results indicate that the aqueous extract of H. umbellata possesses acute inflammatory activity which may be mediated by either inhibition or by blocking the release of prostaglandins and histamine, thus supporting the usage of the plant in traditional medicine treatment of inflammation.

Analgesic activity of aqueous extract of Stereospermum kunthianum (Cham, Sandrine Petit) stem bark.

The analgesic activity of the aqueous extract of Stereospermum kunthianum stem bark was studied using the acetic acid-induced writhing, the hot plate test, tail flick test, and formalin pain test in mice or rats. The aqueous extract (100, 200 or 400 mg/kg) produced a significant (p<0.001) dose-dependent inhibition of abdominal writhes in mice. The results of the hot plate test showed a dose-related and time-dependent significant (P<0.001) increase in pain threshold in mice 60 minutes after treatment at all the doses used in the study. The extract (100, 200 or 400 mg/kg) showed significant (p <0.05) dose-dependent increase in tail flick latency in rats and also inhibited both phases of the formalin pain test in mice with a more intense effect on the first phase than the second phase. The results indicate that the aqueous extract of Stereospermum kunthianum stem bark possesses analgesic activity which is mediated through both central and peripheral mechanisms. This is a possible rationale for its use in traditional human medicine for pain relief.