Abstract--1. Flavonoids relaxed the contractions induced by noradrenaline, KCI or phorbol 12-myristate,13-acetate in rat aortic strips, the order of potency being: flavonols (quercetin, kaempferol, pentamethylquereetin)>flavones(luteolin, apigenin)>flavanols((+)-catechin, (-)-epicatechin) which correlates with the reported order of potency to inhibit protein kinase C.2. The relaxant effects of kaempferol and luteolin were slightly potentiated by isoprenaline and those of pentamethylquercetin, kaempferol and apigenin by sodium nitroprusside.3. It is concluded that the main vasodilatory mechanism of flavonoids seems to be the inhibition of protein kinase C. Inhibition of cyclic nucleotide phosphodiesterases or decreased Ca 2+ uptake may also contribute to their vasodilatory effects.

The antidiarrhoeic activity of the Euphorbia hirta whole plant was investigated. The lyophilized decoction demonstrated antidiarrhoeic activity in experimental models of diarrhoea induced by castor oil, arachidonic acid, and prostaglandin E2. It showed no activity when magnesium sulphate was used to provoke the diarrhoea. The lyophilized decoction delayed small intestinal transit when this was accelerated by castor oil but not in normal conditions. A flavonoid, quercitrin, with antidiarrhoeic activity was isolated from this crude drug.

No abstract

The aerial parts of R. tomentosus were collected during the flowering period (March, 1991) in Velez Benaudalla (Granada, Spain), as populations observed in this area were pure and did not overlap with other species of Rosmarinus. The plant's identity was confirmed by the Department of Botany (Dr. Oswaldo Socorro), Faculty of Pharmacy, University of Granada. The specimens are currently deposited in the GDA (Faculty of Pharmacy, Herbarium, University of Granada) under catalogue number 19471. Total ext ractfor testing The ethanolic extract used for testing was obtained by continuous extraction of 1200 g dried aerial parts from R. tomentosus in a Soxhlet device. This ethanolic extract of R. tomentosus was characterized by thin-layer chromatography: polyphenols (solvent system toluene-ethyl acetate-acetic acid 42 : 30: 9, with FeC1, and UV 320 nm); sterols and triterpenes (solvent system tolueneacetone-acetic acid 100: 3 : 0.7; with Liebermann-Burchard reagent and 110°C). Fractionation of extract Among the different genera of the Lamiaceae family known to have antioxidant and antihepatotoxic properties is the genus Rosmarinus. Unlike the species Rosmarinus officinalis (1-3), which has been the subject of many recent studies, the species Rosmarinus tomentosus is still relatively unknown. This species is found in a completely defined area in the south of the province of Granada (Spain). Both the absence of knowledge about this species, together with its local endemic nature, have led us to begin this study. here, the alcoholic extract and its frac-1.5 x 105M).

ABSTRACT. 1. Flavonoidsproducedaconcentration.dependentrelaxationofthecontractileresponses induced by noradrenaline, KCI, or phorbo112-myristate-13-acetate in rat aortic rings. Only the flavonoid with three contiguous hydroxyls in B rings (myricetin), at low concentrations, potentiates the contractions evoked by these agonists.2. The relaxant effects of flavanone on the noradrenaline-induced contractions were potentiated by isoprenaline and those of morin, chrysin, flavanone, and naringenin by sodium nitroprusside.3. Several mechanisms are implicated in the vasodilatory effects of flavonoids: inhibition of protein kinase C; inhibition of cyclic nucleotide phosphodiesterases; and/or decreased Ca z + uptake. OEN PHAP.MAC 27;2:273-277, 1996.

The hypoglycemic activity of olive leaf was studied. Maximum hypoglycemic activity was obtained from samples collected in the winter months, especially in February. One of the compounds responsible for this activity was oleuropeoside, which showed activity at a dose of 16 mg/kg. This compound also demonstrated antidiabetic activity in animals with alloxan-induced diabetes. The hypoglycemic activity of this compound may result from two mechanisms: (a) potentiation of glucose-induced insulin release, and (b) increased peripheral uptake of glucose.

We studied the importance of the smooth vascular muscle endothelium in the vasodilator action of the decoction of olive (Olea europaea) leaf. The decoction caused relaxation of isolated rat aorta preparations both in the presence (IC50 1.12 +/- 0.33 mg/ml) and in the absence (IC50 1.67 +/- 0.16 mg/ml) of endothelium. The results indicate that the relaxant activity of the lyophilized decoction is independent of the integrity of the vascular endothelium. We also showed that oleuropeoside is a component responsible for vasodilator activity but, from the results, it seems likely that at least one other principle is to be found in the olive leaf which is either a vasodilator itself or else potentiates the relaxant effect of oleuropeoside.

The essential oil of Bupleurum fruticescens was investigated qualitatively and quantitatively by GC and GC-MS analyses. The anti-inflammatory activity of the whole essential oil and its major components was also investigated in the rat hindpaw edema model induced by carrageenin or by PGE1. The anti-inflammatory activity shown by the essential oil can be attributed to the two major components, alpha-pinene and beta-caryophyllene. In order to know the role of the adrenal glands in the anti-inflammatory activity exerted by the two major components of the essential oil, they were studied against the carrageenin-induced hindpaw edema in adrenolectomized rats. It is concluded that alpha-pinene needs the integrity of the adrenal glands to exert its anti-inflammatory activity, as opposed to beta-caryophyllene which was also active in adrenolectomized animals.