The characterization of the activity of a bark extract from Fagara martinicensis on the rat vas deferens

OBJECTIVE: An aqueous extract made from the bark of Fagara martinicensis (family Rutaceae) was examined for its effect on the isolated rat vas deferens. METHOD: The investigation involved measurement of isometric tension in the prostatic and epididymal portions of the isolated rat vas deferens which was anchored in an organ bath with physiological solution. Non-cumulative doses of Fagara martinicensis (FM) were added to the bath and the effects examined in the presence of receptor antagonists to characterize the actions of FM. Results before and after antagonist additions were compared. RESULTS: Non-cumulative addition of FM (1.6 mg/ml to 14.1 mg/ml) produced contractions of both portions of the vas deferens, with the epididymal portion showing greater sensitivity to the effects of FM. The contractions consisted of a rhythmic component superimposed on a phasic and tonic component. All components of the contractions were abolished by prazosin (2.1 uM), a selective a1-adrenoreceptor antagonist, and therefore it was concluded that FM contractions are due to agonist activities on these receptors. Since stimulation of a1-adrenoreceptora results in the mobilization of extracellular calcium into the muscle, the involvement of extracellular calcium was investigated with calcium channel antagonist, nifedipine (0.11-6.0 uM). Nifedipine inhibited all components of the contraction. This effect indicates that entry of extracellular calcium into the muscle was involved in all components of the contraction and further confirms a1-adrenoreceptor agonist action of Fagara martinicensis. CONCLUSIONS: Fagara martinicensis may therefore be a potential source of drugs with a1-adrenoreceptor agonist properties. (AU)

Investigation of the anti-inflammatory properties of leaves of Artocarpus altilis (breadfruit)

OBJECTIVE: The leaves of the breadfruit tree (Artocarpus altilis) are used in folklore medicine in the Caribbean to relieve pain and inflammmation. Our objective was to determine whether there is any scientific basis to this folkloric claim. METHODS: An aqueous decoction of breadfruit leaves (BL) was prepared, and tested for anti-inflammatory activity using the "carrageenan induced rat paw oedema" method. Groups of rats were given doses of BL (15, 30 and 60 mg/kg) and saline (control). Additional experiments were done on isolated guinea pig trachea challenged with acetylcholine (Ach), prostaglandin E2 (PGE2), bradykinin and histamine to investigate the mechanism of action of BL. RESULTS: BL at a dose of 60 mg/kg exhibited significant anti-inflammatory activity (p<0.05) from 0.5 to 4 hours. Lower doses of BL (15 and 30 mg/kg) did not produce any significantly different effects from control (p>0.05). BL antagonized the actions of PGE2 and bradykinin on the trachea but not that of Ach or histamine. CONCLUSION: Our findings suggests that an extract of the breadfruit leaves contains one or more compounds with significant anti-inflammatory properties. However, further studies are required to isolate these compounds and to determine their pharmacological profile. (AU)