Dual effect of quercetin on rat isolated portal vein smooth muscle contractility.

This study examined the effects of quercetin on spontaneously contracting portal veins isolated from healthy young adult male and female Wistar rats (250-300 g). Quercetin (10(-7)-10(-4) M) always produced significant biphasic effects, comprising an initial brief stimulant effect (rise in basal tone), followed by a sustained, longer-lasting secondary relaxant (inhibitory) effect on the venous tissues. The initial brief contractions of the venous muscle preparations were not modified by preincubation of the tissues with prazosin (10(-6) M), suggesting that the initial upsurge in basal tone and increases in contractile frequencies of the venous tissues were probably not mediated via alpha1-adrenoceptor stimulation.

Sclerocarya birrea (A. Rich) Hochst. ['Marula'] (Anacardiaceae): a review of its phytochemistry, pharmacology and toxicology and its ethnomedicinal uses.

A plethora of ethnotherapeutic properties and pharmacological actions have been attributed to Sclerocarya birrea (family: Anacardiaceae). It is one of the most highly valued indigenous trees of southern Africa. Reports in biomedical literature have indicated the presence of medicinally-important chemical constituents in the plant, notably: polyphenols, tannins, coumarins, flavonoids, triterpenoids, phytosterols, and so forth.

Spasmolytic effect of Psidium guajava Linn. (Myrtaceae) leaf aqueous extract on rat isolated uterine horns.

Globally, primary dysmenorrhoea is one of the most frequent gynaecological disorders in young women. It is associated with increased uterine tone, and exaggerated contractility of uterine smooth muscles. In many rural African communities, a number of medicinal plants, including Psidium guajava Linn.

Antidiarrhoeal activity of Psidium guajava Linn. (Myrtaceae) leaf aqueous extract in rodents.

The leaf of Psidium guajava Linn. (family: Myrtaceae) is used traditionally in African folk medicine to manage, control and/or treat a plethora of human ailments, including diarrhoea. In this study, we examined the antidiarrhoeal activity of Psidium guajava leaf aqueous extract (PGE) on experimentally-induced diarrhoea in rodents.