Anti‐inflammatory properties of cryptolepine

Cryptolepine is the major alkaloid of the West African shrub, Cryptolepis sanguinolenta . Cryptolepine has been shown to inhibit nitric oxide production, and DNA binding of Nuclear Factor‐kappa B following inflammatory stimuli in vitro . In order to validate the anti‐inflammatory property of this compound in vivo , we investigated its effects on a number of animal models of inflammation. Cryptolepine (10–40 mg/kg i.p.) produced significant dose‐dependent inhibition of the carrageenan‐induced rat paw oedema, and carrageenan‐induced pleurisy in rats. These effects were compared with those of the non‐steroidal anti‐inflammatory drug indomethacin (10 mg/kg). At doses of 10–40 mg/kg i.p., cryptolepine inhibited lipopolysaccharide (LPS)‐induced microvascular permeability in mice in a dose‐related fashion. Oral administration of up to 40 mg/kg of the compound for four consecutive days did not induce gastric lesion formation in rats. Analgesic activity was also exhibited by cryptolepine through a dose‐related (10–40 mg/kg i.p.) inhibition of writhing induced by i.p. administration of acetic acid in mice. The results of this study reveal that cryptolepine possesses in vivo anti‐inflammatory activity. Copyright © 2009 John Wiley & Sons, Ltd.