Evaluation of diuretic efficacy and antiurolithiatic potential of ethanolic leaf extract of Annona squamosa Linn. in experimental animal models.

OBJECTIVE: The study is to investigate the diuretic and antiurolithiatic activities of ethanolic leaf extract of Annona squamosa Linn. in experimental animals. MATERIALS AND METHODS: For both studies, Wistar albino rats and two doses of extract (250 and 500 mg/kg) were used. Diuretic activity was evaluated by Lipschitz model. Urine volume and urine pH were noted, the concentration of sodium and potassium was estimated by flame photometry, and diuretic index, natriuretic index, and Lipschitz values were calculated from the results. Furosemide was used as a positive control. Ethylene glycol-induced urolithiasis model was used for antiurolithiatic study. Urine volume, urine pH, body weight, and biochemical parameters such as calcium, urea, uric acid, and creatine both from serum and urine were estimated. Antioxidant parameters and histopathological analysis of the kidney were evaluated. Cystone was used as a positive control in this study. Results were expressed as mean ± standard error of mean. Statistical analysis was carried out using one-way analysis of variance, followed by Dunnett's multiple comparison tests. RESULTS: In both diuretic and antiurolithiatic studies, both doses of the extract showed efficacy, and the dose of 500 mg/kg has shown a significant effect compared to positive control and negative control. CONCLUSION: The dose of 500 mg/kg showed a promising diuretic and antiurolithiatic activity.

Geniposide in Gardenia jasminoides var. radicans Makino modulates blood pressure via inhibiting WNK pathway mediated by the estrogen receptors.

OBJECTIVES: To investigate the effects of geniposide in an iridoid found in Gardenia jasminoides var. radicans Makino (GJRM) in spontaneous hypertensive rat (SHR) and explore the possible mechanisms. METHODS: In this study, we detected the content of geniposide in GJRM by high-performance liquid chromatography (HPLC). Then, we used acute diuretic experiments to determine whether geniposide has diuretic effect. Moreover, we carried out experiments on SHR to further study the mechanism of hypertension, while real-time PCR, Western blot and immunohistochemistry were used for the experiments in vivo test. Hypotonic model was used for in vitro test. KEY FINDINGS: Our data showed that the content of geniposide in the extract of GJRM is 27.54%. Meanwhile, 50 mg/kg geniposide showed the strongest effect on promoting urine volume. Further study indicated that the extract of GJRM and geniposide could significantly reduce blood pressure and promote the excretion of urine and Na+ in SHR. In addition, geniposide significantly inhibited the activation of the with-no-lysine kinase (WNK) signalling pathway and significantly increases the protein expressions of estrogen receptor α (ERα), estrogen receptor ß (ERß) and G protein-coupled receptor 30 (GPR30) in SHR. In hypotonic model, geniposide significantly inhibits the phosphorylation of NKCC and NCC and could be antagonistic to estrogen receptor antagonists. CONCLUSIONS: Collectively, we would suggest that geniposide may potentially be utilized as an adjunct to existing thiazide and thiazide-like diuretics to control hypertension, mainly through inhibiting the activation of the WNK signalling pathway mediated by the estrogen receptor.

Multi-scale optimisation vs. genetic algorithms in the gradient separation of diuretics by reversed-phase liquid chromatography.

Multi-linear gradients are a convenient solution to get separation of complex samples by modulating carefully the gradient slope, in order to accomplish the local selectivity needs for each particular solute cluster. These gradients can be designed by trial-and-error according to the chromatographer experience, but this strategy becomes quickly inappropriate for complex separations. More evolved solutions imply the sequential construction of multi-segmented gradients. However, this strategy discards part of the search space in each step of the construction and, again, cannot deal properly with very complex samples. When the complexity is too large, the only valid alternative for finding the best gradient is the use of global search methods, such as genetic algorithms (GAs). Recently, a new global approach where the level of detail is increased along the search has been proposed, namely Multi-scale optimisation (MSO). In this strategy, cubic splines are applied to build intermediate curves to define any arbitrary solvent variation function. Subdivision schemes are used to generate the cubic splines and control their level of detail. The search was subjected to a number of restrictions, such as avoiding long elution and favouring a balanced peak distribution. The aim of this work is evaluating and comparing the results of GAs and MSO. Both approaches were tested with a set of 14 diuretics and probenecid, eluted with acetonitrile-water mixtures using a C18 column. Satisfactory baseline resolution was obtained with an analysis time of 15-16 min. We found that GAs optimisation offered results equivalent to those provided by MSO, when the penalisation parameters were included in the cost function.

Role of the NO/cGMP pathway and renin-angiotensin system in the hypotensive and diuretic effects of aqueous soluble fraction from Crataegus songarica K. Koch.

ETHNO-PHARMACOLOGICAL RELEVANCE: Fruits of Crataegus songarica K. Koch. (Rosaceae) are commonly used in folk medicine for their diuretic properties to treat hypertension and congestive heart failure. To date, no scientific data has been published to support the diuretic potential. AIM OF THE STUDY: The purpose of this study was to evaluate efficacy and mechanism underlying the hypotensive and diuretic action of C. songarica in normotensive rats and to determine the constituents from the extracts by LC-DAD-MS. MATERIALS AND METHODS: Firstly, phytochemical profiling and antioxidant potential of C. songarica extracts was determined. Then, to evaluate changes in blood pressure, different groups of anesthetized normotensive rats were intravenously treated with crude extract (CS-Cr, 10-80 mg/kg), aqueous soluble (AS-CS, 0.1-20 mg/kg), and n-butanol soluble fractions of C. songarica (BS-CS, 1-80 mg/kg). The diuretic effects of CS-Cr (100-500 mg/kg, p.o), AS-CS (100-300 mg/kg, p.o) and BS-CS (100-300 mg/kg, p.o) were evaluated in comparison with hydrochlorothiazide (HCTZ, 10 mg/kg, p.o). The urinary volume, sodium, potassium and pH were estimated in the sample collected for 6 h from saline-loaded rats. Using pharmacological antagonists or inhibitors, we determine the involvement of acetylcholine, prostaglandins, and nitric oxide in C. songarica induced hypotensive and diuresis action. In addition, the activities of angiotensin converting enzyme, erythrocytary carbonic anhydrase and renal Na+/K+/ATPase were evaluated in vitro. RESULTS: From the LC-DAD-MS analyses, thirty-nine compounds were detected, showing a complex chemical profile and an expressive antioxidant activity "in vitro". Acute treatment with CS-Cr, AS-CS, and BS-CS exhibited significant hypotensive and diuretic potential in normotensive rats. However, AS-CS produced most potent and significant dose-dependent hypotension in normotensive rats, and also produced highly significant diuretic and saluretic effects. Despite the changes in urinary excretion of electrolytes, the plasmatic levels of sodium and potassium were not changed. Previous treatment with atropine and L-NAME significantly reduced the hypotensive and diuretic action of AS-CS in normotensive rats. Moreover, the 7-day treatment with AS-CS also resulted in significant ACE inhibitory activity. CONCLUSION: This research supports and extends the ethnomedicinal use of C. songarica as diuretic and hypotensive agent. The results showed that AS-CS from C. songarica could present compounds responsible for hypotensive and diuretic activities with no signs of toxicity, and these effects could involve nitric oxide pathway activated by muscarinic receptors or/and inhibition of angiotensin converting enzyme.

Effects of myricetin-3-O-α-rhamnoside (myricitrin) treatment on urinary parameters of Wistar rats.

OBJECTIVES: This study aimed to investigate the diuretic efficacy of myricetin-3-O-α-rhamnoside (myricitrin), a common naturally occurring plant-derived flavonoid, obtained from Marlierea eugeniopsoides (D.Legrand & Kausel) D.Legrand leaves in rats. METHODS: For that, female Wistar rats were treated by oral route with the different treatments and kept in metaboloic cages for 8-h or 24-h experiment. The volume and urinary parameters were measured at the end of the period and compared between groups. KEY FINDINGS: When orally given to rats and compared to the vehicle-treated group, myricitrin (0.3 and 1 mg/kg) was able to stimulate rat diuresis, natriuresis and kaliuresis. The combination myricitrin plus hydrochlorothiazide, but not plus furosemide or amiloride, potentiated the urinary volume when compared to the effects of drugs alone. Besides, the 8-h renal effects of myricitrin were prevented in the presence of a cyclooxygenase inhibitor and a muscarinic receptor antagonist. However, all groups treated with myricitrin showed a significant reduction in Cl- excretion. In addition, a reduction in the urinary excretion of Cl- and HCO 3 - was detected on 24-h analysis, a result that showed to be associated with an increase of these anions in the blood samples from the myricitrin-treated group. Despite these alterations, no changes in urinary or blood pH were detected. CONCLUSIONS: Taking together, although the results of this study point to the diuretic potential of myricitrin, the reduction in urinary Cl- and HCO 3 - excretion should be considered in future approaches, as well as for therapeutic applicability.

Analgesic, anti-inflammatory and diuretic activities of Macrotyloma uniflorum (Lam.) Verdc.

Macrotyloma uniflorum (Lam.) Verdc. (Papilionaceae) is commonly known as Horse gram and Kulthi. The seeds are reported as anthelmintic, diaphoretic, diuretic and emmenagogue. It is also useful in asthma, bronchitis and urolithiasis. In the present study, analgesic, anti-inflammatory and diuretic effects of the methanol extract of Macrotyloma uniflorum seeds were evaluated in doses of 200 and 400mg/kg. Significant results were obtained in all activities.

The acute diuretic effect of an ethanolic fraction of Phyllanthus amarus (Euphorbiaceae) in rats involves prostaglandins.

BACKGROUND: Phyllanthus amarus (Schum & Thonn), a plant belonging to the family of Euphorbiaceae is used in Ivorian traditional medicine to treat cardiovascular disorders such as hypertension. However, although this plant has been described as a diuretic agent, the underlying mechanism remains unclear. Therefore, the aim of the present study was to investigate the mechanism action of diuretic effects of an ethanolic fraction of Phyllanthus amarus (EFPA) in rats. METHODS: Effects of EFPA on urinary excretion were carried out for doses ranging from 5 to 80 mg/kg given by intraperitoneal injection (i.p.) and compared with that induced by furosemide (5 mg/kg) after 8 h. Thereafter, the diuretic activity of EFPA was also evaluated in the presence of indomethacin (5 mg/kg, i.p.) in order to determine the involvement of prostaglandins, after 24 h. RESULTS: Between 5 and 80 mg/kg, EFPA induced a significant urinary excretion. The profile of urinary excretion showed that after 2 h, the highest dose of 80 mg/kg induced a urinary volumetric excretion (UVE), which was similar to that induced by furosemide. After 24 h, EFPA at 10 mg/kg increased significantly UVE, Na+ (43 mEq) and Cl¯ (97 mEq) urinary excretions without promoting kaliuresis. In rats pretreated with indomethacin, the urinary excretion and the natriuretic response of EFPA were significantly reduced. CONCLUSION: Altogether, this study has shown that EFPA promotes a significant urinary excretion of water and Na+, confirming its diuretic activity. Moreover, the increased diuresis could be attributed, at least in part, to the involvement of prostaglandins.

Evaluation of anti-urolithiatic and diuretic activities of watermelon (Citrullus lanatus) using in vivo and in vitro experiments.

Traditionally, Citrullus lanatus is known to have protective properties in kidney diseases and for having the ability to clear urine. Current study aims to validate the traditional uses of C. lanatus by evaluation of anti-urolithiatic and diuretic activities using in vivo and in vitro experiments. Male Wistar rats were used for in vivo anti-urolithiatic and diuretic activities. Supersaturated solution of calcium and oxalate was used for in vitro crystallization study. Hematoxylin & eosin staining was used for histopathological evaluation of kidney. In the in vivo rat model of urolithiasis, the pulp extract reduced calcium oxalate (CaOX) crystal count in both kidney and urine. The pulp extract also increased the urinary pH and output, and prevented the weight loss. Serum analysis showed elevation in creatinine clearance and reduction in urea and creatinine levels. Urinary analysis demonstrated that pulp extract restored altered phosphate, calcium, oxalate, and citrate levels. In the in vivo rat model of diuresis; the pulp extract produced diuresis, reduced serum chloride levels, and elevated urinary sodium and chloride levels. In the in vitro crystallization experiment, pulp extract inhibited the aggregation phase. Seed extract failed to show any convincing results. GC-MS analysis revealed the presence of steroids and alkanes as the major constituents of pulp extract, which might be responsible for anti-urolithiatic activity; however, further studies are required for isolation and identification of active constituents. Current study validated the traditional uses of watermelon and demonstrated that pulp extract possessed significant anti-urolithiatic and diuretic activities.

Restoration of plasma markers of liver and kidney functions/integrity in alloxan-induced diabetic rabbits by aqueous extract of Pleurotus tuberregium sclerotia.

The effect of aqueous extract of the sclerotia of Pleurotus tuberregium on the plasma electrolytes, and markers of liver and kidney functions/integrity of normal and alloxan-induced rabbits was investigated. Diabetes mellitus was induced by injection of alloxan (120mg/kg body weight), via the marginal ear vein. The extract was administered orally at 100, 200 and 300mg/kg (both to normal and diabetic rabbits), and metformin at 50mg/kg. Gas chromatographic-flame ionization detector analysis of the extract revealed the presence of twelve known phenolic acids, consisting mainly of caffeic acid (80.24%), chlorogenic acid (11.08%), piperic acid (6.11%), sinapinic acid (2.14%) and ferulic acid (0.34%). Compared to test control, the treatment significantly (p<0.05) lowered plasma activities of alkaline phosphatase, gamma glutamyltransferase, and alanine and aspartate transaminases. Also lowered were plasma unconjugated/conjugated bilirubin ratio and concentrations of urea, blood urea nitrogen, creatinine, sodium, and total and unconjugated bilirubin. It however, significantly (p<0.05) raised plasma potassium and calcium levels. Therefore, the modulation of plasma sodium and potassium is an indication of the diuretic potential of the extract. In addition, the extract had no deleterious effect on the liver and kidney of the treated animals, at least at the doses administered in this study.

Chemical composition and diuretic, natriuretic and kaliuretic effects of extracts of Mimosa bimucronata (DC.) Kuntze leaves and its majority constituent methyl gallate in rats.

OBJECTIVES: Some species of the genus Mimosa showed promising results in previous investigations, which include diuretic effect; however, no chemical analyses or animal model has been conducted so far to evaluate the biological properties of M. bimucronata. METHODS: Male Wistar rats received the oral treatment with vehicle; hydrochlorothiazide; methanolic extract from M. bimucronata (MEMB), dichloromethane (DCM) and ethyl acetate (EA) fractions or methyl gallate (MG). The cumulative urine volume, electrolytes excretion, pH and osmolality were determined at the end of the experiment. KEY FINDINGS: The chemical studies demonstrated that the phenolic compounds are the majorities in the plant, with the MG being the main substance identified. We showed that MEMB and EA fraction, but not DCM, exhibited diuretic and saluretic effects. Similarly, the MG also revealed diuretic, natriuretic and kaliuretic properties to both normotensive and spontaneously hypertensive rats. Atropine, a muscarinic receptor antagonist, fully prevented MG-induced diuresis and saluresis. In addition, MG did not alter the viability of A7r5 and L929 cell lines and neither stimulated nitric oxide generation. CONCLUSIONS: These findings suggest that M. bimucronata extracts and its majority compound MG present diuretic, natriuretic and kaliuretic properties, which was dependent on the activation of muscarinic acetylcholine receptor.

Phytochemical and biological assessments on Lipidium meyenii (maca) and Epimidium sagittatum (horny goat weed).

The effects of Lipidium meyenii (maca, LM) and Epimidium sagittatum (horny goat weed, ES) have been investigated due to their involvement in fertilization. Both of the drugs showed good results before, during and after fertilization in male and female mice. The results revealed that the crude extract of Lipidium meyenii caused a significant decrease in the no. of writhes at 300 and 500mg/kg (p<0.05) as compare to control, Epimidium sagittatum and standard drug. The gross behavioral, open field, exploratory behaviour, forced swimming test for stress, diuretic activity, chronic toxicity with the effect on reproduction of both male and female and change in body weight were also studied. The phytochemical study showed the presence of tannin, alkaloid, carbohydrate, rich protein and absence of sterol in LM, whereas ES shows presence of sterol and less protein. LS improve in muscle activity and exploratory behaviours without any toxic effects on mice and their pups. It does not have diuretic effect for first two hour but act normally after initial phase of drug therapy. Epimidium sagittatum has dual action that is at low dose it has slight stimulation action and at high dose little depressive effect. ES also has some diuretic effect. Overall these results suggest that LM is highly effective remedy for treatment of impotency and reduces stress and depression, because of dual effect ES not only suggested as an anxiolytic medicine but also effective in female hormonal disorder.

Two-phase and three-phase liquid-phase microextraction of hydrochlorothiazide and triamterene in urine samples.

This paper reports the applicability of two-phase and three-phase hollow fiber based liquid-phase microextraction (HF-LPME) for the extraction of hydrochlorothiazide (HYD) and triamterene (TRM) from human urine. The HYD in two-phase HF-LPME is extracted from 24 mL of the aqueous sample into an organic phase with microliter volume located inside the pores and lumen of a polypropylene hollow fiber as acceptor phase, but the TRM in three-phase HF-LPME is extracted from aqueous donor phase to organic phase and then back-extracted to the aqueous acceptor phase, which can be directly injected into HPLC for analysis. Under optimized conditions preconcentration factors of HYD and TRM were obtained as 128 and 239, respectively. The calibration curves were linear (R(2) ≥ 0.995) in the concentration range of 1.0-100 µg/L for HYD and 2.0-100 µg/L for TRM. The limits of detection for HYD and TRM were 0.5 µg/L. The intra-day and inter-day RSD based on four replicates were obtained as ≤5.8 and ≤9.3%, respectively. The methods were successfully applied for determining the concentration of the drugs in urine samples. Copyright © 2015 John Wiley & Sons, Ltd.

Ethnopharmacological investigation of the diuretic and hemodynamic properties of native species of the Brazilian biodiversity.

ETHNOPHARMACOLOGICAL RELEVANCE: Although Echinodorus grandiflorus, Cuphea carthagenensis, and Phyllanthus tenellus infusions are used in Brazilian folk medicine due to their possible diuretic effect, none of these species was critically investigated as a diuretic drug. So, the aim of this study was to evaluate the possible acute diuretic activity of ethanol soluble fractions (ES) obtained from these species and assess the relationship between renal cortical blood flow and their antioxidant and hypotensive activity using normotensive Wistar rats. MATERIAL AND METHODS: The preparation obtained from E. grandiflorus (ES-EG), C. carthagenensis (ES-CC), and P. tenellus (ES-PT) infusions was orally administered in a single dose to rats. Urine excretion rate, pH, density, conductivity and Na(+), K(+), Cl(-) and HCO3(-) contents were measured in the urine of saline-loaded animals. Concentration of electrolytes, total protein, urea, creatinine, and angiotensin converting enzyme (ACE) activity were evaluated in collected serum. The involvement of the renal cortical blood flow and antioxidative activity in the hypotensive and diuretic effects was also determined. RESULTS: Water and Na(+), Cl(-) and Na(+) excretion rates were significantly increased by ES-EG, while urinary bicarbonate excretion was reduced. Moreover, ES obtained from E. grandiflorus was able to significantly increase renal blood flow and reduce mean arterial pressure and oxidative stress in "in vitro" and "in vivo" models. All other parameters evaluated were not affected by any treatment. CONCLUSION: The results presented here shown that the ES-EG obtained from E. grandiflorus leaves shown a significant diuretic and hypotensive activity and suggest that these effects could be related with an important renal and systemic vasodilator effect. In addition, it was shown for the first time that the pharmacological effects of ES obtained from P. tenellus and C. carthagenensis do not support its popular use as a diuretic agent.

Hypotensive and diuretic effect of the butanolic soluble fraction of the hydroethanolic extract of bark of Scutia buxifolia Reissek in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Scutia buxifolia, a native tree popularly known as "coronilha", is widely used in Brazilian folk medicine for diuretic and anti-hypertensive purposes. AIM OF THE STUDY: We investigated the effects of a butanolic (BuOH) soluble fraction of the hydroethanolic extract (HESB) of bark of Scutia buxifolia on both blood pressure and urinary excretion of rats. The involvement of the nitric oxide/guanylate cyclase pathway in the hypotensive effect found was also explored. MATERIAL AND METHODS: We tested the effect of the BuOH soluble fraction of HESB on the mean arterial pressure (MAP) of anesthetized rats. The fraction was administered at doses of 1, 3 and 10mg/kg (i.v.) in normotensive rats during continuous infusion of vehicle (10 µl/min), or phenylephrine (4 µg/kg/min), or l-NAME (7 mg/kg/min), two approaches able to induce a sustained hypertensive state. In some experiments, a bolus injection of ODQ (2mg/kg) was administered in animals infused with phenylephrine before the administration of the BuOH soluble fraction of HESB. We also measured the effects of the BuOH soluble fraction on the MAP of spontaneously hypertensive rats (SHR). Separate groups of rats were treated orally with either HESB (10, 30 or 100mg/kg), or its BuOH soluble fraction (3, 10 or 30 mg/kg), and were subjected to measurement of diuresis and blood pressure. RESULTS: The BuOH soluble fraction of HESB (10mg/kg, i.v.) reduced the MAP of both phenylephrine-infused and SHR rats by 20.6 ± 6.0 and 41.8 ± 8.3 mm Hg, respectively. However, no hypotensive effect was found in normotensive animals infused with l-NAME, a non-selective inhibitor of nitric oxide synthase, or animals previously treated with the soluble guanylate cyclase inhibitor ODQ. The urinary excretion was increased by 70% at 6-8h after a single oral administration of the BuOH soluble fraction of HESB (10mg/kg), without change in urinary density, pH, or Na(+) and K(+) concentrations. In addition, MAP was lower 3h after the acute oral treatment with the BuOH soluble fraction (82.1 ± 3.8 mm Hg), compared with MAP of animals from the control group (97 ± 3.2 mm Hg). CONCLUSION: This study demonstrates that the BuOH soluble fraction of the hydroethanolic bark of Scutia buxifolia, which has its bark used in folk medicine for the treatment of hypertension mainly by its presumed diuretic properties, possesses both diuretic and hypotensive effects in rats, and that at least the hypotensive effect is fully dependent on activation of the nitric oxide/guanylate cyclase pathway.

Diuretic and anti-diuretic activities of fractions of Alismatis rhizoma.

ETHNOPHARMACOLOGICAL RELEVANCE: Alismatis rhizoma or Alisma orientale (Zexie in Chinese), the dried rhizome of Alisma orientale Juzepzuk (Alismataceae), is a well-known traditional Chinese medicine and is used as an agent for diuresis and for excreting dampness in China and Japan. In this paper, we report the diuretic activities of the petroleum ether fraction, the ethyl acetate fraction, the n-buthanol fraction, and the remaining fraction, of the ethanol extract of Alismatis rhizoma (AR). MATERIALS AND METHODS: The single dose of the petroleum ether fraction, the ethyl acetate fraction, the n-buthanol fraction, and the remaining fraction, of the ethanol extract of AR were orally administered to rats. Urinary excretion rate, pH and electrolyte excretion were measured in the urine of saline-loaded rats. RESULTS: In this study, the 100 and 400mg/kg doses of the ethyl acetate fraction and the 12.5, 25 and 50mg/kg doses of the n-butanol fraction all produced an increase in urine volume excretion, and all produced a remarkable increase in urine electrolyte excretion. Although the 800mg/kg doses of the ethyl acetate fraction, the 75 and 100mg/kg doses of the n-butanol fraction and the 12.5, 25 and 50mg/kg doses of the remaining fraction significantly decreased the urine output in 6h, the urine Na(+) and Cl(-) excretion were markedly decreased with the n-butanol fraction (75 and 100mg/kg doses) and the remaining fraction (12.5, 25 and 50mg/kg doses) while the ethyl acetate fraction at 800mg/kg doses had slight effect on urine electrolyte excretion. The petroleum ether fraction did not show remarkable diuretic activity in comparison with control group. CONCLUSIONS: Our present study determined that the ethyl acetate fraction and the n-butanol fraction present notable diuretic effects, and we found a dual effect on renal function showed by AR, including promoting diuretic activity and inhibiting diuretic activity. The components with strong polarities in AR may have anti-diuretic activities, which might be an effect of promoting the sodium-chloride co-transporter in the distal tubule.

Sclederma of Poria cocos exerts its diuretic effect via suppression of renal aquaporin-2 expression in rats with chronic heart failure.

ETHNOPHARMACOLOGICAL RELEVANCE: Sclederma of Poria cocos (Hoelen) has been used as a diuretic in traditional Asian medicine. However, the underlying mechanism by which Sclederma of Poria cocos (hoelen) exerts its diuretic effect has not been well identified. The aim of the present study was to evaluate the effects of Sclederma of Poria cocos (hoelen) in rats with chronic heart failure (CHF) induced by acute myocardial infarction and to investigate the underlying mechanisms. MATERIALS AND METHODS: An aqueous extract of Sclederma of Poria cocos (hoelen) (2.4 g/kg/d, 1.2 g/kg/d or 0.6 g/kg/d) or furosemide (20 mg/kg/d) was administered orally to male Sprague-Dawley rats starting on the day of coronary ligation. The urine output of all rats was quantified and collected every day for 1 or 4 weeks. The expression of aquaporin-2 (AQP2) was examined after treatment for 1 or 4 weeks. RESULTS: Urinary output increased significantly and urinary osmolality decreased after oral administration of Sclederma of Poria cocos (hoelen) for both 1 and 4 weeks. Sclederma of Poria cocos (hoelen) caused less electrolyte disorder than furosemide. Furthermore, Sclederma of Poria cocos (hoelen) reduced the levels of plasma BNP in CHF rats, whereas furosemide had no effect. Importantly, both mRNA and protein expression of AQP2 were down-regulated and urinary excretion of AQP2 was decreased after administration of Sclederma of Poria cocos (hoelen) to CHF rats. Similarly, Sclederma of Poria cocos (hoelen) reduced plasma arginine vasopressin (AVP) level and down-regulated vasopressin type 2 receptor (V2R) mRNA expression. CONCLUSIONS: Sclederma of Poria cocos (hoelen) exerts its diuretic effect and improves cardiac function in CHF rats via the AVP-V2R-AQP2 axis.

Evaluation of the diuretic activity of the aqueous and 80% methanol extracts of Ajuga remota Benth (Lamiaceae) leaves in mice.

BACKGROUND: In the Ethiopian traditional medicine, the leaves of Ajuga remota B. (Local name, Armagusa) is used in the treatment of hypertension. Since this claim has not been investigated scientifically, the aim of the present study was to evaluate the diuretic potential of the aqueous and 80% methanol extracts of the leaves of Ajuga remota in mice after acute oral administration. METHODS: Adult mice were administered orally either aqueous (250 mg/kg, AA250; 500 mg/kg, AA500 and 1000 mg/kg, AA1000) or 80% methanol (250 mg/kg, AM250; 500 mg/kg, AM500 and 750 mg/kg, AM750) extract. Urine output and electrolyte contents were then quantified up to 5 h and compared with those administered with furosemide 10 mg/kg (F10) and distilled water (CON). RESULTS: The larger dose of 80% methanol extract produced significant diuresis (p < 0.01), while the aqueous extract had shown diuresis both at the middle (p < 0.01) and higher (p < 0.01) doses by the end of the fifth hour compared to CON mice. Regarding electrolyte excretion, larger doses of both extracts had increased natriuresis (p < 0.001 for AA1000 and p < 0.01 for AM1000), while the effect on kaliuresis were smaller when compared with the standard, suggesting the plant could possibly have a potassium-sparing effect. Phytochemical screening revealed the presence of secondary metabolites like phenolic compounds, tannins, saponins, flavonoids, terpenoids, steroids, and cardiac glycosides, which might account for the diuretic activity. CONCLUSIONS: The results indicate that the plant is endowed with significant diuretic activity at various doses, providing evidence for its folkloric use. The major components like flavonoids, tannins, terpenoids and alkaloids found in the plant might have contributed to the observed diuretic activity.

Diuretic and anti-diuretic activities of the ethanol and aqueous extracts of Alismatis rhizoma.

ETHNOPHARMACOLOGICAL RELEVANCE: Alismatis rhizoma or Alisma orientale (Zexie in Chinese), the dried rhizome of Alisma orientale Juzepzuk (Alismataceae), is a well-known traditional Chinese medicine and is used as an agent for diuresis and for excreting dampness in Asia and Europe. In this paper, we report the diuretic activities of the ethanol extract (EE) and the aqueous extract (AE) of A. rhizoma (AR). MATERIALS AND METHODS: The EE and AE were orally administered to rats. The urinary excretion rate and pH, and electrolyte excretion were measured in the urine of saline-loaded rats. RESULTS: The results showed that EE could increase the urine output at 2.5, 5 and 10mg/kg doses but decrease the urine output at 20, 40 and 80mg/kg doses compared with the control group. The 5 and 10mg/kg doses of EE increased the urine electrolyte excretion, but the effects on Na(+)/K(+) values were too weak to reach statistical significance. The Na(+) excretion and Cl(-) excretion were markedly decreased with the 20, 40 and 80mg/kg doses of EE, but the effect on K(+) excretion was notably slight. All of the tested doses of AE produced an increase in urinary excretion, but the increase did not reach statistical significance. CONCLUSIONS: This study identified that EE but not AE presents a notable diuretic effect, and EE had diuretic and anti-diuretic effects, which appears to be related to the sodium-chloride co-transporter in the renal distal convoluting tubule. This study demonstrated for the first time that the EE of AR has a dual effect on renal function, including promotion of diuretic activity at lower doses and inhibiting diuretic activity at higher doses, and the AR dose should be given more attention in clinical applications. This study will play a critical and guiding role in the dosing of AR as a diuretic drug in clinical applications.

Synchronized separation of seven medications representing most commonly prescribed antihypertensive classes by using reversed-phase liquid chromatography: Application for analysis in their combined formulations.

A reversed-phase high-performance liquid chromatography method was developed for the simultaneous determination of the diuretic, hydrochlorothiazide, along with six drugs representing the most commonly prescribed antihypertensive pharmacological classes such as atenolol, a selective ß1 blocker, amlodipine besylate, a calcium channel blocker, moexipril hydrochloride, an angiotensin-converting-enzyme inhibitor, valsartan and candesartan cilexetil, which are angiotensin II receptor blockers, and aliskiren hemifumarate, a renin inhibitor, using irbesartan as an internal standard. The chromatographic separation was achieved using acetonitrile/sodium phosphate dibasic buffer (0.02 M, pH 5.5) at a flow rate of 1 mL/min in gradient elution mode at ambient temperature on a stationary phase composed of an Eclipse XDB-C18 (4.6 × 150 mm, 5 µm) column. UV detection was carried out at 220 nm. The method was validated according to ICH guidelines. Linearity, accuracy, and precision were satisfactory over the concentration ranges of 2-40 µg/mL for hydrochlorothiazide and candesartan cilexetil, 20-120, 10-160, 5-40, 20-250, and 5-50 µg/mL for atenolol, valsartan, moexipril hydrochloride, aliskiren hemifumarate, and amlodipine besylate, respectively. The method was successfully applied for the determination of each of the studied drugs in their combined formulations with hydrochlorothiazide. The developed method is suitable for the quality control and routine analysis of the cited drugs in their pharmaceutical dosage forms.

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.