Potential low toxic alternative for Na-Cl cotransporter inhibition: A diuretic effect and mechanism study of Pyrrosia petiolosa.

BACKGROUND: Hydrochlorothiazide, a diuretic commonly used for the treatment of hypertension, is often associated with serious metabolic side effects. Pyrrosia petiolosa (Christ) Ching is a traditional Chinese medicine that possesses diuretic properties, without any obvious side effects. AIM: To evaluate the diuretic effect of P. petiolosa (Christ) Ching and to elucidate its underlying mechanism of action. METHODS: Extracts obtained from different polar components of P. petiolosa (Christ) Ching were analyzed for toxicity in a Kunming mouse model. The diuretic effects of the extracts were compared to that of hydrochlorothiazide in rats. In addition, compound isolation procedures, cell assays of Na-Cl cotransporter inhibition and rat diuretic test of monomeric compounds were conducted to identify the active ingredients in the extract. Subsequently, homology modeling and molecular docking were performed to explain the reason behind the diuretic activity observed. Finally, LC-MS analysis was used to elucidate the underlying mechanism of action of P. petiolosa (Christ) Ching. RESULTS: No toxicity was observed in mice administered P. petiolosa (Christ) Ching extracts. The ethyl acetate fraction showed the most significant diuretic effect. Similar results were obtained during the analysis for Na+ content in rat urine. Further separation of P. petiolosa (Christ) Ching components led to the isolation of methyl chlorogenate, 2',3'-dihydroxy propyl pentadecanoate, and ß-carotene. Results from cell assays showed that the Na-Cl cotransporter inhibitory activity of methyl chlorogenate was greater than that of hydrochlorothiazide. This result was again confirmed by the diuresis tests of monomeric compounds in rats. The molecular simulations explain the stronger interactions between the methyl chlorogenate and Na-Cl cotransporter. Of the compounds determined using LC-MS analysis, 185 were identified to be mostly organic acids. CONCLUSIONS: P. petiolosa possesses significant diuretic activities without any obvious toxicity, with least two possible mechanisms of action. Further study on this herb is warranted.

Anti-inflammatory and diuretic effects of the diterpene ent-dihydrotucumanoic acid.

Gymnosperma glutinosum (Spreng) Less (Asteraceae) is a shrub used in traditional medicine for the treatment of inflammatory and renal diseases. The ent-dihydrotucumanoic acid (DTA) is a diterpene obtained from G. glutinosum. This study evaluated the antioxidant, genotoxic, and diuretic properties of DTA, as well as its in vitro and in vivo anti-inflammatory actions. The antioxidant actions of DTA were assessed with the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) assays, the genotoxic action was assessed with the comet assay, and the diuretic effects of DTA were assessed using metabolic cages. The anti-inflammatory actions were evaluated using primary murine peritoneal macrophages stimulated with LPS and the λ-carrageenan-induced hind paw edema test. DTA lacked antioxidant (IC50 > 25,000 µg/mL) activity in the ABTS, FRAP, and DPPH assays. DTA at 500-1,000 µg/mL showed moderate genotoxicity. In LPS-stimulated macrophages, DTA showed IC50 values of 74.85 µg/mL (TNF-α) and 58.12 µg/mL (NO), whereas the maximum inhibition of IL-6 (24%) and IL-1ß (36%) was recorded at 200 µg/mL. DTA induced in vivo anti-inflammatory effects with ED50 = 124.3 mg/kg. The in vitro anti-inflammatory activity of DTA seems to be associated with the decrease in the release of TNF-α and NO. DTA promoted the excretion of urine (ED50 = 86.9 mg/kg), Na+ (ED50 = 66.7 mg/kg), and K+ (ED50 = 8.6 mg/kg). The coadministration of DTA with L-NAME decreased the urinary excretion shown by DTA alone. Therefore, the diuretic activity is probably associated with the participation of nitric oxide synthase. In conclusion, DTA exerted anti-inflammatory and diuretic effects, but lacked antioxidant effects.

Ethnopharmacological approaches to kidney disease-prospecting an indigenous species from Brazilian Pantanal.

ETHNOPHARMACOLOGICAL RELEVANCE: Although Luehea divaricata Mart. (Malvaceae) is popularly used by the population of the Brazilian Pantanal for the treatment of different types of kidney diseases, no study has been carried out to prove this ethnobotanical indication. AIM: To investigate the possible cardiorenal effects of an herbal preparation obtained from L. divaricata leaves. MATERIALS AND METHODS: First, to provide quality control standards, a detailed morphological and microchemical characterization of L. divaricata leaves was performed. Then, the purified aqueous extract was obtained from the leaves of this species (ESLD) and a thorough phytochemical characterization was performed. Subsequently, acute oral toxicity test was performed after single administration of different doses (5, 50, 300, 2000mg/kg) in male and female Wistar rats. Finally, the diuretic, hypotensive and antioxidant properties of ESLD (30, 100, 300mg/kg) were evaluated after acute and prolonged treatment and the role of angiotensin converting enzyme, aldosterone, vasopressin, and nitric oxide in these effects was investigated. RESULTS: Analyses performed by liquid chromatography-mass spectrometry showed that the main secondary metabolites present in ESLD were flavonol O-glycosides and flavone C-glycosides. Acute and prolonged treatment with ESLD was able to expressively increase urinary volume and electrolyte excretion. Mean blood pressure and systolic blood pressure were also significantly reduced after acute treatment. Moreover, treatment with ESLD was able to reduce thiobarbituric acid reactive species and increase serum nitrate levels. CONCLUSION: The data obtained showed that ESLD has an important diuretic and hypotensive effect, which is probably dependent on the reduction of oxidative stress and increased bioavailability of nitric oxide.

Colectomy induces an aldosterone-mediated increase in jejunal glucose uptake in rats.

AIMS: The main function of the colon is water and electrolyte absorption. Total colectomy eliminates this colonic function and may alter the absorptive capacity of the small intestine for nutrients. This study examines the effect of total colectomy on jejunal glucose absorption and investigates the potential role of aldosterone in mediating the alterations in glucose uptake post-colectomy using the aldosterone antagonist spironolactone. MAIN METHODS: Total colectomy with ileo-rectal anastomosis was performed on anesthetized rats. Sham rats were identically handled without colon resection. Two days post-surgery, groups of colectomized rats were injected with either a daily subcutaneous dose of spironolactone or sesame oil for 12days. Body weight changes and food and water intake were measured in all experimental groups. Glucose absorption was measured by in-vivo single pass perfusion in the rat jejunum of control, sham, colectomized, colectomized with spironolactone, and colectomized with sesame oil treatment. Na/K ATPase, SGK1, SGLT1 and GLUT2 expressions were determined in jejunal mucosa in control, colectomized and colectomized/spironolactone injected rats by Western blot analysis. Histological assessment was performed on jejunal sections in control and colectomized groups. KEY FINDINGS: Glucose absorption significantly increased in colectomized rats with an observed increase in Na/K ATPase and SGK1 expression. No significant expression change in SGLT1 and GLUT2 was detected in the jejunum in colectomized rats. Spironolactone, however, significantly decreased the glucose uptake post-colectomy and normalized Na/K ATPase and SGK1 expression. SIGNIFICANCE: Our results suggest that jejunal glucose uptake increases post-colectomy as a possible consequence of an aldosterone-mediated function.

Evaluation of the diuretic activity of the aqueous and 80% methanol extracts of the root of Euclea divinorum Hiern (Ebenaceae) in Sprague Dawley rats.

BACKGROUND: Diuretics are drugs that increase the formation of urine and are important for the treatment of various diseases including hypertension and edema. The root decoction of Euclea divinorum has been used as a diuretic agent in the traditional medicine. Therefore, this study was aimed to evaluate the diuretic activity of the crude extracts of the roots of Euclea divinorum in Sprague Dawley rats. METHODS: The aqueous extract (AE) and 80% methanol extract (80ME) of the plant were prepared using decoction and maceration, respectively. Vehicle (distilled water, 10ml/kg), standard drug (hydrochlorothiazide, 10mg/kg) and three doses (100mg/kg, 200mg/kg and 400mg/kg) of the AE and 80ME were given to male rats by oral gavage. Parameters like urine volume (for 5h), electrolyte concentration and pH were measured (at 5th h) and analyzed. Data were analyzed using one way analysis of variance (ANOVA) followed by Tukey post hoc test. Linear regression was also applied to show the dose dependency nature of the diuretic effect. RESULTS: The result indicated that the 80ME of the plant significantly (p<0.05) produced diuresis at 200mg/kg and 400mg/kg. Furthermore, the AE produced significant diuresis (p<0.05) at all doses. With regard to the electrolyte excretion, the AE produced significant natriuresis and kaliuresis at all tested doses (p<0.001), while the 80ME showed significant natriuresis and kaliuresis at 200mg/kg (p<0.01) and 400mg/kg (p<0.001). Preliminary phytochemical screening revealed the presence of secondary metabolites, including saponins, flavonoids, glycosides, steroids, tannins and terpinoids in both extracts. These constituents might be responsible for the diuretic activity of Euclea divinorum. Both extracts were also found to be safe at 2000mg/kg on the acute toxicity study. CONCLUSION: This finding provides a scientific support for the acclaimed traditional use of the roots of Euclea divinorum as a diuretic agent.

Terminalia arjuna bark extract improves diuresis and attenuates acute hypobaric hypoxia induced cerebral vascular leakage.

ETHNOPHARMACOLOGICAL RELEVANCE: Terminalia arjuna (Roxb. ex DC.) Wight & Arn. (T. arjuna) has been widely used in the traditional ayurvedic system of medicine as a cardioprotectant and for acute and chronic renal diseases supporting its ethnopharmacological use. AIM OF THE STUDY: The present study aimed at evaluating the diuretic action of an alcoholic extract of T. arjuna and its possible use as a prophylactic to prevent vascular leakage during acute mountain sickness at high altitude. MATERIALS AND METHODS: Rats were exposed to hypobaric hypoxia simulated to an altitude of 27,000 ft. in a decompression chamber for 12h. T. arjuna bark extract was administered at a single dose of 150 mg/kg (p.o.) to male Sprague Dawley rats (200 ± 20 g) 30 min prior to exposure. Total urine volume was measured during exposure to hypobaric hypoxia. The animals were then investigated for cerebral vascular leakage and serum concentration of sodium, potassium, renin, angiotensin-II, aldosterone and atrial natriuretic peptide (ANP). RESULTS: T. arjuna ameliorated acute hypobaric hypoxia induced decrease in glomerular filtration rate (p<0.5), increased total urine output (p<0.5) and prevented cerebral vascular leakage in hypoxic rats. T. arjuna treated animals also showed decrease in serum levels of renin (p<0.001) and angiotensin-II (p<0.5) as compared to placebo treated animals. Administration of T. arjuna attenuated acute hypobaric hypoxia induced oxidative stress, improved aldosterone levels and altered electrolyte balance in animals through ANP dependent mechanism. CONCLUSION: Results of the present study indicate towards diuretic potential of hydro-alcoholic extract of T. arjuna bark and provide evidence for its novel application as a prophylactic to attenuate acute hypobaric hypoxia induced cerebral vascular leakage through ANP mediated modulation of renin-angiotensin-aldosterone system.

Diuretic activity and toxicity of some Verbascum nigrum extracts and fractions.

CONTEXT: Verbascum nigrum L. (Scrophulariaceae) is a perennial plant used in folk medicine for the treatment of kidney diseases due to its presumable diuretic properties. OBJECTIVE: We investigated the diuretic activity and toxicity of extracts from different parts of V. nigrum and identified a group of compounds responsible for the biological effect. MATERIALS AND METHODS: Five ethanol extracts from herb, roots, flowers, leaves and stems as well as five fractions of polar compounds isolated from herb of V. nigrum were orally administrated as a single dose of 50 mg/kg to rats. Urinary excretion and electrolyte content were measured at 3 and 6 h after the treatment. The acute toxicity of the V. nigrum extracts and fractions was evaluated in mice. RESULTS: All extracts, except the one prepared from the roots, showed a significant increase of the urine output within first 3 h after their administration. The extract from stems was the most active, inducing urine output of 14.6 ± 0.8 ml/kg BW versus 5.2 ± 1.4 ml/kg BW of the control. It also demonstrated saluretic activity with a natriuretic index 4.1 and a kaliuretic index 3.8. The diuretic activity was correlated with the flavonoid content in the plant organs. Flavonoid fractions demonstrated significant activity; the higher content of flavonoids (expressed as hesperidin) translated into more pronounced diuretic (35.9 ± 2.1 ml/kg BW) and saluretic effects (natriuretic index 4.5 and kaliuretic index 5.4). CONCLUSION: The diuretic activity of traditionally used V. nigrum was validated experimentally. The pharmacological effect was attributed to flavonoids, which accumulated in aerial parts of the plant, mainly in stems.

[Acute diuretic effect of ethanolic and aqueous extracts of Ceratopteris pteridoides (Hook) in normal rats]. / Efecto diurético agudo de los extractos etanólico y acuoso de Ceratopteris pteridoides (Hook) en ratas normales.

INTRODUCTION: Ceratopteris pteridoides is a semiaquatic fern of the Parkeriacea family, widely used in the Colombian folk medicine as a diuretic and cholelithiasic, of which there are no scientific reports that validate its popular use. OBJECTIVE: To evaluate the acute and short-term repeated-dose diuretic effect of the ethanolic and aqueous extracts of C. pteridoides in an in vivo model. MATERIALS AND METHODS: The total ethanolic extract was obtained by maceration of the whole plant of C. pteridoides with ethanol and the aqueous extract by decoction at 60°C for 15 minutes. Both extracts were evaluated in preliminary phytochemical analysis and histological studies after the administration of the extracts for 8 consecutive days (1000 mg/Kg). The diuretic effect was evaluated using Wistar rats treated with the extracts (500 mg/Kg), using an acute and a short-term repeated-dose model, and quantifying water elimination, sodium and potassium excretion by atomic absorption spectrophotometry, and chloride excretion by mercurimetric titration. RESULTS: In the acute model both extracts showed significant diuretic, natriuretic, and kaliuretic effect compared to the control group. Whereas, a short-term repeated-dose administration showed a diuretic effect without elimination of electrolytes. The histopathologic study did not suggest a toxic effect in liver or kidney. CONCLUSION: The results represent evidence of the diuretic activity of C. pteridoides and give support the popular use given to this plant in the north coast of Colombia. Further studies are required to isolate and identify the compounds responsible for the activity and the mechanism of action involved.

Efecto diurético agudo de los extractos etanólico y acuoso de Ceratopteris pteridoides (Hook) en ratas normales / Acute diuretic effect of ethanolic and aqueous extracts of Ceratopteris pteridoides (Hook) in normal rats

Introducción. Ceratopteris pteridoides es un helecho semiacuático de la familia Parkeriacea, ampliamente utilizado en la medicina popular colombiana como diurético y colelitiásico, sobre el cual no existen reportes científicos que avalen su uso popular como diurético. Objetivo. Evaluar el efecto diurético agudo en dosis única y dosis repetidas a corto plazo, de los extractos etanólico y acuoso de C. pteridoides en un modelo in vivo . Materiales y métodos. El extracto etanólico total fue obtenido por maceración de la planta entera de C. pteridoides con etanol y el extracto acuoso fue obtenido por decocción a 60 °C por 15 minutos. Ambos extractos se sometieron a análisis fitoquímico preliminar y estudio histológico posterior a la administración de los extractos durante ocho días consecutivos (1.000 mg/kg). El efecto diurético se evaluó en ratas Wistar, tratadas con los extractos (500 mg/kg), en forma aguda y en dosis repetidas a corto plazo, cuantificando la eliminación de agua y la excreción renal de sodio y potasio por espectrofotometría de absorción atómica y, de cloruros, por titulación mercurimétrica. Resultados. En el modelo agudo, ambos extractos mostraron un significativo efecto diurético y de excreción renal de sodio y potasio en comparación con el control, mientras que con la administración en dosis repetidas a corto plazo mostraron efecto diurético sin eliminación de electrolitos. El estudio histopatológico no sugirió efectos tóxicos hepáticos o renales. Conclusión. Los resultados demuestran la actividad diurética de C. pteridoides y sustentan el uso popular dado a esta planta como diurético en la costa norte colombiana. Se requieren estudios posteriores que permitan aislar e identificar los compuestos responsables de la actividad y los mecanismos de acción involucrados.

Introduction. Ceratopteris pteridoides is a semiaquatic fern of the Parkeriacea family, widely used in the Colombian folk medicine as a diuretic and cholelithiasic, of which there are no scientific reports that validate its popular use. Objective. To evaluate the acute and short-term repeated-dose diuretic effect of the ethanolic and aqueous extracts of C. pteridoides in an in vivo model. Materials and methods. The total ethanolic extract was obtained by maceration of the whole plant of C. pteridoides with ethanol and the aqueous extract by decoction at 60°C for 15 minutes. Both extracts were evaluated in preliminary phytochemical analysis and histological studies after the administration of the extracts for 8 consecutive days (1000 mg/Kg). The diuretic effect was evaluated using Wistar rats treated with the extracts (500 mg/Kg), using an acute and a short-term repeated-dose model, and quantifying water elimination, sodium and potassium excretion by atomic absorption spectrophotometry, and chloride excretion by mercurimetric titration. Results. In the acute model both extracts showed significant diuretic, natriuretic, and kaliuretic effect compared to the control group. Whereas, a short-term repeated-dose administration showed a diuretic effect without elimination of electrolytes. The histopathologic study did not suggest a toxic effect in liver or kidney. Conclusion. The results represent evidence of the diuretic activity of C. pteridoides and give support the popular use given to this plant in the north coast of Colombia. Further studies are required to isolate and identify the compounds responsible for the activity and the mechanism of action involved.

Diuretic activity and acute oral toxicity of Palicourea coriacea (Cham.) K Schum.

AIM OF THE STUDY: Palicourea coriacea (Cham.) K Schum, is an endemic plant used in the Midwestern Region of Brazil, popularly known as "douradinha do campo" and "congonha do campo". This plant has been used in traditional medicine for several ailments, especially to treat kidney diseases. Since no formal studies on the biological activities and medicinal properties of the ethanolic extract of Palicourea coriacea (PCEE) have been carried out previously, the present study represents the first research into the efficacy of this plant as a diuretic agent employing laboratory rats as test animals. MATERIALS AND METHODS: For diuretic activity evaluation we assayed three doses of PCEE (20, 40 and 80mg/kg) and measurement of the urinary volume and electrolytes (Na(+), K(+)) concentration were taken. The acute oral toxicity of PCEE was investigated according to OECD Guideline 423. RESULTS: The oral administration of a single dose of PCEE significantly increased the urinary volume in 24h. Additionally, the treatment with PCEE increased, in a dose-dependent manner, the excretion of both, Na(+) and K(+). No sign of toxicity was observed in the animals. CONCLUSIONS: The present study confirmed the ethnopharmacological use of Palicourea coriacea as a diuretic agent in the experimental condition tested here. Additionally, this work supports the importance of the preservation of local knowledge as well as the conservation of Brazilian biodiversity.

Acute toxicity and diuretic studies of the roots of Asparagus racemosus Willd in rats.

OBJECTIVE: Asparagus racemosus Willd has been used as diuretic in Ayurveda but has not been validated by a suitable experimental model. Hence the present study was undertaken. MATERIALS AND METHODS: The study was carried out with an aqueous extract of the roots of Asparagus racemosus utilizing three doses viz 800 mg/kg, 1600 mg/kg and 3200 mg/kg for its diuretic activity in comparison with standard drug (furosemide) and control (normal saline) rats after doing acute toxicity study. RESULTS: Acute toxicity study showed no fatality even with the highest dose and the diuretic study revealed significant diuretic activity (p < 0.05) in the dose of 3200 mg/kg. CONCLUSION: Asparagus racemosus showed diuretic activity at a 3200 mg/kg dose without acute toxicity.

Diuretic activity of squamate mistletoe, Viscum angulatum.

Viscum angulatum Heyne ex DC (Viscaceae) is a leafless hemiparasitic shrub traditionally used in Asian countries for the treatment of hypertension. In the present study, the methanol extract of the whole plant was examined for diuretic activity in rats. The activity was evaluated using parameters such as urine volume after 5, 19, and 24 h and urine sodium, potassium, and chloride concentrations. The extract was further scrutinized for polyphenolic compounds and triterpenoids. The extract demonstrated a significant increase in and dose-dependent effect on urine excretion volume in comparison to the normal group in the tested range of 100-400 mg/kg. The extract demonstrated comparable saluretic and higher natriuretic activity (Na(+)/K(+)) compared to the furosemide treated group. However, the Cl(-)/Na(+) + K(+) ratio, which indicates carbonic anhydrase mediated activity, remained unaffected. HPLC and quantitative analysis of the extract revealed that polyphenolic compounds and the triterpenoid, oleanolic acid, are the major phytochemicals, and are proposed to be responsible for the observed diuretic effect. Oleanolic acid has been reported to possess diuretic activity with significant potassium loss in rats. In contrast to pure oleanolic acid, the extract demonstrated a valuable potassium-sparing effect. This suggests modulation of the diuretic effect of oleanolic acid by polyphenolics present in the extract. The observed dose-dependent potassium-sparing diuretic effect is a hereto unreported property of this plant.

Acute toxicity and diuretic studies of the roots of Asparagus racemosus willd in rats / Toxicidad aguda y estudios diuréticos del espárrago racemoso willd en ratas

OBJECTIVE: Asparagusracemosus Willd has been used as diuretic in Ayurveda but has not been validated by a suitable experimental model. Hence the present study was undertaken. MATERIALS AND METHODS: The study was carried out with an aqueous extract of the roots of Asparagus racemosus utilizing three doses viz 800 mg/kg, 1600 mg/kg and 3200 mg/kg for its diuretic activity in comparison with standard drug (furosemide) and control (normal saline) rats after doing acute toxicity study. RESULTS: Acute toxicity study showed no fatality even with the highest dose and the diuretic study revealed significant diuretic activity (p < 0.05) in the dose of 3200 mg/kg. CONCLUSION: Asparagus racemosus showed diuretic activity at a 3200 mg/kg dose without acute toxicity.

OBJETIVO: El espárrago racemoso Willd ha sido usado como diurético en ayurveda pero no ha sido validado mediante un modelo experimental conveniente. De ahí la razón para emprender el presente estudio. MATERIALES Y MÉTODOS: El estudio fue realizado con extracto acuoso de raíces de espárrago racemoso, utilizando tres dosis, a saber, 800 mg/kg, 1600 mg/kg y 3200 mg/kg para analizar su actividad diurética, comparándolo con el medicamento estándar (furosemida), y ratas de control (solución salina normal) después de hacer un estudio de toxicidad aguda. RESULTADOS: El estudio de toxicidad aguda no mostró fatalidad, incluso con la dosis más alta, y el estudio del diurético reveló una actividad diurética significativa (p < 0.05) con la dosis de 3200 mg/kg. CONCLUSIÓN: El espárrago racemoso mostró actividad diurética en una dosis de 3200 mg/kg sin toxicidad aguda.

Computational models for drug inhibition of the human apical sodium-dependent bile acid transporter.

The human apical sodium-dependent bile acid transporter (ASBT; SLC10A2) is the primary mechanism for intestinal bile acid reabsorption. In the colon, secondary bile acids increase the risk of cancer. Therefore, drugs that inhibit ASBT have the potential to increase the risk of colon cancer. The objectives of this study were to identify FDA-approved drugs that inhibit ASBT and to derive computational models for ASBT inhibition. Inhibition was evaluated using ASBT-MDCK monolayers and taurocholate as the model substrate. Computational modeling employed a HipHop qualitative approach, a Hypogen quantitative approach, and a modified Laplacian Bayesian modeling method using 2D descriptors. Initially, 30 compounds were screened for ASBT inhibition. A qualitative pharmacophore was developed using the most potent 11 compounds and applied to search a drug database, yielding 58 hits. Additional compounds were tested, and their K(i) values were measured. A 3D-QSAR and a Bayesian model were developed using 38 molecules. The quantitative pharmacophore consisted of one hydrogen bond acceptor, three hydrophobic features, and five excluded volumes. Each model was further validated with two external test sets of 30 and 19 molecules. Validation analysis showed both models exhibited good predictability in determining whether a drug is a potent or nonpotent ASBT inhibitor. The Bayesian model correctly ranked the most active compounds. In summary, using a combined in vitro and computational approach, we found that many FDA-approved drugs from diverse classes, such as the dihydropyridine calcium channel blockers and HMG CoA-reductase inhibitors, are ASBT inhibitors.

Acute and chronic diuretic effect of ethanolic extract of leaves of Cocculus hirsutus (L.) Diles in normal rats.

OBJECTIVES: The objective of this study was to evaluate the acute and chronic diuretic effect of the ethanolic extract of the leaves of Cocculus hirsutus (L.) Diles. METHODS: The ethanolic extract was administered (100, 200 and 400 mg/kg, p.o.) in Wistar rats. In the acute study, rats received drugs orally and urine was collected after 1, 2, 3, 4, 5 and 6 h. The chronic study involved repeated administration of ethanolic extract for 28 days and urine was collected on day 1, 7, 14, 21 and 28. The parameters were total urine volume, concentration of Na+, K+ and Cl- ions, creatinine in urine and serum. Urine output, electrolytes (Na+, K+ and Cl- ions) and creatinine were determined on day 7, 14, 21 and 28. KEY FINDINGS: The highest dose (400 mg/kg) of the ethanolic extract significantly (P < 0.01) enhanced urine output. Excretion of cations (Na+ and K+ ions) and anions (Cl- ions) increased significantly with respect to the control (gum acacia 2% dissolved in saline, 10 ml/kg) group. The increase of cations in the urine after treatment with ethanolic extract was dose dependent. The ethanolic extract of the leaves of C. hirsutus (100, 200 and 400 mg/kg) and furosemide (10 mg/kg) did not significantly change the concentration of Na+, K+ and Cl- ions in serum. The ethanolic extract of the leaves of C. hirsutus (100, 200 and 400 mg/kg) and furosemide (10 mg/kg) increased the excretion of creatinine in urine but with a corresponding decrease in serum. CONCLUSIONS: It was concluded that the ethanolic extract of the leaves of C. hirsutus (400 mg/kg) had significant diuretic effect in rats.

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.

Estudio toxicológico y farmacológico de los extractos hidroalcohólicos de algunas especies de Smilax de Centroamérica / No disponible

Se determinó la toxicidad subcrónica y el efecto diurético, hipoglucemiante, ansiolítico y sedante de los extractos hidroalcohólicos de las raíces y rizomas Smilax engleriana, S. panamensis,S. regelii, S. subpubescens,S. kunthiiy dos quimiotipos de S. domingensis: Costa Rica (CR) y Guatemala (G). Ningún extracto resultó mortal ni causó anormalidad histológica a una dosis diaria de 2 g/kg durante 90 días, aunque algunos provocaron signos de deshidratación y disminución del peso corporal. S. panamensisy S. domingensis CR y G provocaron un efecto diurético en ratones hembra, que se mantuvo una semana después de cesar el tratamiento con S. domingensisCR y S. panamensis(efecto residual). S. engleriana y S. regelii mostraron actividad diurética, con efecto residual, en ratones machos. S. englerianamostró efecto hipoglucemiante residual en ratones machos y hembras, mientras que el extracto de S. kunthiilo mostró sólo en machos y S. panamensis y S. domingensis CR, solamente en hembras. Se observó un posible efecto ansiolítico con S. domingensis CR y S. kunthii (AU)

Subchronic toxicity and diuretic, hypoglycemic, ansiolytic and sedative effects were determined in mice after treatment with hydroalcholic extracts obtained from roots and rhizomes of Smilax engleriana, S. panamensis, S. regelii, S. subpubescens, S. kunthiiand two chemotypes of S. domingensis:Costa Rica (CR) and Guatemala (G). None of the extracts caused mortality nor histologic abnormalities at 2g/kg when given daily for 90 days. However, some extracts induced signs of dehydration and a decrease in body weight. S. panamensisand S. domingensis(CR and G) showed diuretic activity in female mice, maintaining the effect for one week after having suspended the treatment with S. domingensis CR and S. panamensis (residual effect). S. englerianaand S. regelii showed diuretic activity with a residual effect in male mice. S. engleriana induced a hypoglycaemic residual effect in female and male mice, whereas S. kunthiishowed the effect only in males and S. panamensis and S. domingensis CR only in females. A possible anxiolytic effect was observed with S. domingensisCR and S. kunthii (AU)

Sox2 and JAGGED1 expression in normal and drug-damaged adult mouse inner ear.

Inner ear hair cells detect environmental signals associated with hearing, balance, and body orientation. In humans and other mammals, significant hair cell loss leads to irreversible hearing and balance deficits, whereas hair cell loss in nonmammalian vertebrates is repaired by the spontaneous generation of replacement hair cells. Research in mammalian hair cell regeneration is hampered by the lack of in vivo damage models for the adult mouse inner ear and the paucity of cell-type-specific markers for non-sensory cells within the sensory receptor epithelia. The present study delineates a protocol to drug damage the adult mouse auditory epithelium (organ of Corti) in situ and uses this protocol to investigate Sox2 and Jagged1 expression in damaged inner ear sensory epithelia. In other tissues, the transcription factor Sox2 and a ligand member of the Notch signaling pathway, Jagged1, are involved in regenerative processes. Both are involved in early inner ear development and are expressed in developing support cells, but little is known about their expressions in the adult. We describe a nonsurgical technique for inducing hair cell damage in adult mouse organ of Corti by a single high-dose injection of the aminoglycoside kanamycin followed by a single injection of the loop diuretic furosemide. This drug combination causes the rapid death of outer hair cells throughout the cochlea. Using immunocytochemical techniques, Sox2 is shown to be expressed specifically in support cells in normal adult mouse inner ear and is not affected by drug damage. Sox2 is absent from auditory hair cells, but is expressed in a subset of vestibular hair cells. Double-labeling experiments with Sox2 and calbindin suggest Sox2-positive hair cells are Type II. Jagged1 is also expressed in support cells in the adult ear and is not affected by drug damage. Sox2 and Jagged1 may be involved in the maintenance of support cells in adult mouse inner ear.

Acute toxicity and diuretic studies of Rungia repens aerial parts in rats.

Ethanolic extract of Rungia repens aerials parts (300 and 600 mg/kg p.o) showed diuretic activity in rats. The acute toxicity, orally evaluated in mice, was found to be higher than 3000 mg/kg.

Cardiovascular effects of the South American medicinal plant Cecropia pachystachya (ambay) on rats.

Cecropia pachystachya is used in South America for relieving cough and asthma. In Argentina it is known as "ambay" and grows in the neotropical forests (Ntr C.p.) and in temperate hilly regions (Tp C.p.). To evaluate their cardiovascular profile, the effect of extracts obtained from plants growing in the neotropical region as well as in temperate areas were compared by i.v. administration in normotensive rats. The following parameters were measured: blood pressure (BP) and heart rate (HR). The hypotensive effect was stronger for Ntr C.p., which aqueous extract decreased BP at doses between 90 and 300 mg lyophilised/kg until 46.2 +/- 12% of basal. The extract of Tp C.p. reduced BP to 86.1 +/- 11% of basal (p < 0.05 respect to Ntr C.p.) at 180 mg/kg, but increased HR at 90 and 180 mg/kg (until 133.6 +/- 10.8% of basal, p < 0.05) and produced death by respiratory paralysis at 320 mg/kg (about 3g dry leaves/kg). The hypotensive effects, but not the chronotropic ones, were attenuated by pretreatment with reserpine (5 mg/kg). The plant extracts had not diuretic activity by oral administration in conscious rats, nor produced vasodilation of perfused hindquarters arterial bed precontracted with high-[K] or 100 microM phenylephrine. The results suggest that neotropical ambay is more hypotensive than the one from the temperate hilly region. When it reaches plasma, it could produce hypotension (by central blockade of sympathic innervation of vessels) and tachycardia (by central cholinergic inhibition of heart), although it happens at doses higher than the oral ethnotherapeutic (about 340 mg dried leaves/kg).