Intravenously administered aqueous leaf extract (6.3 to 12.5 mg/kg) in anaesthetised cats and (3.2 to 6.3 mg/kg) in anaesthetised rats, produced a significant fall (P < 0.05, n 10) in the mean, systolic and diastolic blood pressure by as much as 75 mm Hg in cats and 35 10.00mm Hg in rats. On the raised arterial perfusion pressure of the rabbit central ear artery preparation, the extract (12.5-50 sg) produced a transient rise in perfusion pressure, which was followed by a more significant and prolonged fall in the perfusion pressure. Phentolamine (1.0 sg/ml) antagonised the transient rise and propranolol (1.0 tg/ml abolished the fall in perfusion pressure. The results suggested: that vasodilatation, resulting from a combination of alpha-adrenoceptor blockade and beta-adrenoceptor stimulant action of the extract, aided by skeletal muscle relaxation might be responsible for the blood pressure lowering effect of the extract.

SummaryRats fed on a supplement of millet, Guinea-corn, rice or maize given in addition to laboratory stock diet showed a high degree of protection against experimental ulceration following indomethacin administration. A higher degree of protection was shown when the rats were fed with the mixture of the four cereals and laboratory stock diet. The tubers did not offer protection, while a mixture of beans and millet, Guinea-corn, unpolished rice, and maize offered no protection. The significance of such findings with regard to the geographical distribution of duodenal ulcer in Nigeria is discussed.

Aqueous leaf extracts of Lippia multiflora administered intraperitoneally produced a profound calming effect, muscle relaxing action, and significant reduction in the spontaneous locomotor activity of mice measured in the Ugo Basile activity cage. The extract (0.25-1.0 g kgj reduced amphetamine induced locomotor activity in mice. The extract (0.5-1.0 mg mt') inhibited contractions of the isolated rat diaphragm in response to the phrenic nerve stimulation. The muscle relaxant effect was considered to be primarily responsible for the calming effect, bordering on tranquilizing activity observed in mice and rats.

The twitch response of the rat isolated vas deferens to electrical field stimulation, (ito 10 Hz, Ito 2 m. sec.), reduced by noradrenaline (1 to 2 tg ml-') was further enhanced by cryptolepine (5 to 10 .tg ml '). Cryptolepine (0.1 to 0.2 tg mt1) antagonised the inhibition of the twitch produced by clonidine (ito 2 ng m11) but did not antagonise the phenylephrine effect. Cryptolepine (1 to 2ig m1') inhibited the potentiation of the twitch response and contraction of the muscle produced by phenylephrine (0.3 .tg ml1). Potentiation of the twitch produced by cocaine (1 to 5 mi-1) was also enhanced by cryptolepine (i to 2 ig ml'). The results demonstrated by the difference in the concentration of cryptolepine required to block preand post-junctional ct-adrenoceptor effects of clonidine and phenylephrine suggest that cryptolepine has preferential presynaptic a-adrenoceptor blokking action.

Cryptolepine, an alkaloid of Cyprolepsis sanguinolenta (LINI)I.. SCHI FCI-FR) is an antagonist of noradrenaline on the rat isolated vas deferens. It is of about the same potency as phentolamine (PA, of phentolamine = 7.5 + 0.40, pAz of cryptolepine = 6.6 k 0.35). We here report a potentiatory effect of small doses of cryptolepine (3.0 x 10-7-10-6M) on the effect of noradrenaline, an effect which has not been obtained with phentolamine, and methoxamine -induced contractions of the vas deferens. Cocaine antagonised the ~o t e n t i a t o r~ effects of small doses of cryptolepine. Inhibition of neuronal uptake is suggested as the roba able mechanism for the observed potentiation.tolepis sanguinolenta (LI~I)I . SC~II I:( nu), family Asclepiadaceae, [5]. It is a shrub indigenous to tropical Africa and its extracts have found application in traditio-~