Objective: To evaluate the antinociceptive, anti-inflammatory and antidiarrheal activities of the ethanolic calyx extract of Hibiscus sabdariffa Linn. in mice.
Methods: In the present study, the dried calyxes of H. sabdariffa were subjected to extraction with 95% ethanol and the extract was used to investigate the possible activities. Antinociceptive activity of the extract was evaluated by using the acetic acid-induced writhing test. The anti-inflammatory effect of the extract was tested by using the xylene-induced ear edema model mice. Castor oil-induced diarrheal model mice were used to evaluate the antidiarrheal activity of the extract.
Results: In acetic acid-induced writhing test, the extract produced inhibited writhing in mice siginificantly compared with the blank control (P<0.01). The extract showed significant inhibition of ear edema formation in xylene-induced ear edema model mice in a dose-related manner compared with the blank control (P<0.01). The extract demonstrated a significant antidiarrheal activity against castor oil-induced diarrheal in mice in which it decreased the frequency of defecation and increased the mean latent period at the doses of 250 and 500 mg/kg body weight (P<0.01).
Conclusion: The above mentioned findings indicate that the calyx extract of H. sabdarif fa possesses significant antinociceptive, anti-inflammatory and antidiarrheal activities that support its uses in traditional medicine.

Key words: Hibiscus, plant extracts, analgesics, anti-inflammatory agents, antidiarrheals, mice