Diuretic activity of some Smilax canariensis fractions.

ETHNOPHARMACOLOGICAL RELEVANCE: Smilax canariensis is an endemic species of the Canary Islands, popularly known as "Zarzaparrilla sin espinas". The rhizome, leaves and stem of this species has wide use in folk medicine practice on the islands, where they are habitually employed as diuretic. AIM OF THE STUDY: In this paper we report on the diuretic activity in experimental animals of several fractions of the methanol extract of this species. MATERIALS AND METHODS: Four fractions of the methanol extract of the rhizomes, leaves and stem of Smilax canariensis (50 and 100mg/kg), Furosemide and Hydrochlorotiazide (10mg/kg), were orally administered to laboratory animals to evaluate their diuretic activity. Water excretion rate, pH, conductivity, and content of Na(+), K(+) and Cl(-) were measured in the urine of saline-loaded mice. RESULTS: All the studied extracts showed an interesting increase of the diuresis, although the n-buthanol (27%; p<0.05) and ethyl acetate extract (35%; p<0.01), at 100mg/kg p.o., showed the most interesting diuretic activity, which suggested that this diuretic effect is associated with the compounds contained in the fractions of intermediate polarity (ethyl acetate and n-butanol), decreasing in the most extreme apolar and polar sub-extracts (dichloromethane and methanol: water respectively). The increase in diuresis produced by these two extracts was very close to the values of Hydrochlorothiazide (32%) or Furosemide (39%), used as reference diuretics. CONCLUSIONS: These data, together with previous results on the aqueous and methanol extracts, reaffirm assertions made regarding the effectiveness of the extracts of this plant against urinary pathologies in the Canary Islands folk medicine.

Withanolides from Whitania aristata and their diuretic activity.

AIM OF THE STUDY: Withania aristata is an endemic plant used traditionally in Canary Islands as a diuretic. In this paper, we report on this pharmacological activity in several extracts of the dry vegetal material collected and the identification and diuretic activity of two withanolides, one of them previously not reported, isolated from the most active fraction. MATERIAL AND METHODS: Four Whitania aristata extracts at 100 mg/kg were orally administered to laboratory animals to evaluate their diuretic activity. From the most active fraction, two withanolides were isolated. Both and a mixture of them at 5 and 10 mg/kg were analyzed too as diuretics. Water excretion rate and content of Na(+) and K(+) electrolytes were measured in the urine of saline-loaded animals. RESULTS: Whitania aristata water fraction, the two withanolides and the mixture of these compounds displayed high diuretic activity, with a significant excretion of sodium and potassium ions in laboratory animals. CONCLUSIONS: This research supports the ethno-medicinal use of Whitania aristata as diuretic. This activity seems to be associated to the presence of a new type of natural diuretic agents, such as withaferin A and witharistatin.

Diuretic activity of Smilax canariensis, an endemic Canary Island species.

ETHNOPHARMACOLOGICAL RELEVANCE: Smilax canariensis is an endemic species of the Canary Islands, popularly known as "Zarzaparrilla sin espinas". This species has wide use in folk-medicine practice on the islands, especially as diuretic. So the aim of our study is to evaluate the diuretic activity of an aqueous and a methanol extract of this species. MATERIAL AND METHODS: Three infusions doses (250, 500 and 750 mg/kg) and two methanol extract doses (100 and 200 mg/kg) were orally administered to laboratory rats. Water excretion rate, pH, density, conductivity, and content of Na(+) and K(+) were measured in the urine of saline-loaded rats. RESULTS: Water excretion rates were significantly increased in a dose-dependent manner by both hot water infusions and the alcohol extract. The electrolytic excretion was also dose-dependent, although potassium excretion was markedly reduced when using the alcohol extract compared with that observed for the infusion. CONCLUSIONS: Smilax canariensis presents a notable diuretic effect which appeared to be related both to its potassium content and to the presence of polar organic compounds. The present results provide a quantitative basis explaining the traditional folk-medicine use of Smilax canariensis as a diuretic agent by the Canary Island population.

Diuretic activity of some Withania aristata Ait. fractions.

We previously reported on the significant dose-dependent diuretic effects produced in laboratory rats by hot water infusions and methanol extracts of Withania aristata Ait., where notable increases were observed in the excretion of water and sodium, with an interesting potassium-saving effect. The present study gives the results of the diuretic effects in rats of the hexane, dichloromethane, ethyl acetate, butanol and methanol-water fractions of the previously studied methanol extract. Water excretion rate, pH, density, conductivity and content of Na(+), K(+) and Cl(-) were measured in the urine of the rats when subjected to hypersaline conditions. Of the above fractions, the methanol:water extract (100mg/kg) showed the most interesting diuretic activity (25%; p<0.01), which suggested that increase in the polarity of the extracting solvent led to an increase in the concentration of the polar compounds responsible for the diuretic effect. These data, together with previous results on the aqueous and methanol extracts, reaffirm assertions made regarding the effectiveness of the extracts of this plant against urinary pathologies in the Canary Islands folk medicine.

Diuretic activity of Withania aristata: an endemic Canary Island species.

This study reports on the pharmacological evaluation of the diuretic activity of an infusion and a methanol extract of Withania aristata Ait. in laboratory rats. Water excretion rate, pH, density, conductivity, and content of Na(+), K(+) and Cl(-) were measured in the urine of rats subjected to hypersaline conditions. Both the infusion and the methanol extract showed a significant diuretic effect compared with non-treated controls, with notable increases in the rates of water and sodium excretion. There was also a potassium retention effect. The diuretic effect did not appear to be related to the potassium content in the material tested, but did have some relation to its content of active polar compounds. The results justify the use of Withania aristata as a diuretic agent in folk medicine of the Canary Islands.

Diuretic activity of Artemisia thuscula, an endemic Canary species.

A pharmacological evaluation for diuretic activity of infusions at 5, 10 and 15% of Artemisia thuscula Cav. was carried out. Urinary excretion of water, pH, density, conductivity and Na(+), K(+) and Cl(-) content were investigated in saline-loaded rats. The infusions showed a dose-dependent decrease diuretic effect, but augmented significantly with respect to the control group for the urinary excretion of water and sodium. Furthermore, a potassium-sparing effect at 5 and 10% was showed. The diuretic effect does not seem to be related to the potassium content of the starting material. The results justify the use of Artemisia thuscula as diuretic agent by the canary traditional medicine.

Essential oils and antimicrobial activity of two varieties of Cedronella canariensis (L.) W. et B.

The qualitative and quantitative determination of the essential oils of the aerial part of two varieties of Cedronella canariensis (L.) W. et B., namely, C. canariensis var. canariensis and C. canariensis var. anisata have been performed, together with the study of the antimicrobial activity of both oils. The noteworthy inhibition exhibited against Bordetella bronchiseptica and Cryptococcus albidus may justify the popular use of the these plants in the treatment of certain diseases of the respiratory tract.

Cytostatic and antibacterial activity of some compounds isolated from several lamiaceae species from the canary islands.

A chemotherapeutic study has been carried out on thirteen products Eeleven diterpenes, one lignan, (+)-sesamin, and a coumarin, siderin] isolated from SALVIA and SIDERITIS species considered endemic to the Canarian flora. The data obtained suggest that some diterpenoid compounds show an interesting cytostatic activity, specially galdosol ( 6) with an ID (50) value of 0.5 microg/ml. These compounds also evidence a moderate antibacterial activity against Gram positive bacteria.

Contribution to the ethnopharmacological study of the Canary Islands.

A large amount of ethnobotanical data of almost 200 botanical species used for medicinal purposes in the Canary Islands is presented. We are endeavouring to avoid the definitive loss of the islands' phytotherapeutic heritage, in view of the rapid social changes taking place over the last few years and hope that this work may serve to promote further pharmacological research that may confirm, scientifically and experimentally, the information presented here. A brief description of the geographical, botanical and historical circumstances is included. The species listed have been classified according to a basically therapeutical criterion.