Evaluation and estimation of diuretic activity of the linalyl acetate in the rats.

This study aimed to explore the diuretic activity of linalyl acetate (LA). LA is an essential oil, it is an integral phyto-constituent of various plants. In this study, acute and chronic diuretic activities were explored by measuring the levels of different electrolytes and pH in the urine of experimental rats. Rats were divided into five groups. The control group was given 10 mg/kg normal saline, the treated group was given 10 mg/kg furosemide, and the remaining 3 groups received different doses of LA including 25, 50, and 75 mg/kg through intraperitoneal route, to determine its diuretic potential. Urine volume for acute diuretic activity was measured for 6 hours however for chronic diuretic activity was measured for 6 days. For a comparative study of LA with a control group and treated group with reference drug, diuretic index was used. Moreover, the underlying mechanism of the diuretic activity was also explored by comparing atropine, L-NAME, and indomethacin. The results of each group with 6 rats in each group were obtained by ± standard error of the mean of every group. Analysis of Variance (ANOVA) was used for statistical analysis. Results revealed that the LA 75 mg/kg dose showed comparable results as of furosemide. Moreover, this study revealed the involvement of muscarinic receptors to produce diuresis in comparison with atropine with very little involvement of prostanoids and no effect on NO pathway induced by indomethacin and L-NAME respectively. It is concluded that LA possess anti-diuretic potential. Muscarinic receptors might be involved in producing diuretic effects.

Furosemide attenuates tubulointerstitial injury and allows functional testing of porcine kidneys during normothermic machine perfusion.

BACKGROUND: Normothermic machine perfusion (NMP) is a promising pretransplant kidney quality assessment platform, but it remains crucial to increase its diagnostic potential while ensuring minimal additional injury to the already damaged kidney. Interventions that alter tubular transport can influence renal function and injury during perfusion. This study aimed to determine whether furosemide and desmopressin affect renal function and injury during NMP. METHODS: Eighteen porcine kidneys (n = 6 per group) were subjected to 30 min of warm ischemia and 4 h of oxygenated hypothermic perfusion before being subjected to 6 h of NMP. Each organ was randomized to receive no drug, furosemide (750 mg), or desmopressin (16 µg) during NMP. RESULTS: Compared with the other groups, the addition of furosemide resulted in significantly increased urine output, fractional excretion of sodium and potassium, and urea clearance during NMP. Urinary neutrophil gelatinase-associated lipocalin levels decreased significantly with furosemide supplementation compared with the other groups. The addition of desmopressin did not result in any significantly different outcome measurements compared with the control group. CONCLUSIONS: This study showed that the addition of furosemide affected renal function while attenuating tubulointerstitial injury during NMP. Therefore, furosemide supplementation may provide renal protection and serve as a functional test for pretransplant kidney viability assessment during NMP.

A Comprehensive Review of the Pharmacologic Perspective on Loop Diuretic Drug Interactions with Therapeutically Used Drugs.

BACKGROUND: Loop diuretics help to manage the patients with edema associated with congestive heart failure, liver cirrhosis, and renal disease and hypertension. The patients taking loop diuretics may receive other medications to treat comorbidities leading to drug interactions. METHODS: The literature was searched in databases such as Medline/PMC/PubMed, Google Scholar, Cochrane Library, Science Direct, EMBASE, Web of science, Ebsco, Directory of open access journals (DOAJ) and reference lists were used to spot relevant articles using keywords Drug interactions, Pharmacodynamic interactions, Loop diuretics, Bumetanide, Ethacrynic acid, Furosemide, and Torsemide. RESULTS: Loop diuretics are associated with hypokalemia, ototoxicity and other adverse effects. The drugs affected by hypokalemia and having the potential of inducing ototoxicity could interact with loop diuretics pharmacodynamically. Loop diuretics can interact with drugs such as amphotericin B, digoxin, angiotensin-converting enzyme inhibitors (ACE inhibitors), antidiabetic drugs, antifungal agents, dobutamine, gossypoland sotalol due to diuretic associated hypokalemia. In addition, the risk of ototoxicity could be enhanced by the concomitant use of loop diuretics and cisplatin, aminoglycoside antibiotics or phosphodiesterase 5 (PDE 5) inhibitors. Loop diuretics may also interact pharmacodynamically with drugs like cephalosporins, ceritinib, levothyroxine, pixantrone, probenecid, lithium, nonsteroidal anti-inflammatory drugs (NSAIDs), sulfonylureas and herbal drugs. CONCLUSION: Clinicians, pharmacists and other health care providers should take responsibility for the safe use of medications. In addition, they are required to be aware of the drugs interacting with loop diuretics to prevent adverse drug interactions.

Evaluation of the diuretic effect of crude ethanol and saponin-rich extracts of Herniaria glabra L. in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Herniaria glabra L. popularly known in Morocco as "Herras lehjer" which means "Stonebreaker" in English is a plant that has been used in traditional medicine to treat edema, water retention, urinary diseases and renal problems including kidney stones. AIM OF THE STUDY: The present study aims to investigate the diuretic activity of the crude ethanol extract (CEE) and the saponin-rich extract (SRE) of the Herniaria glabra L. METHODS: CEE and SRE were prepared using maceration. SRE was obtained after using the selective liquid-liquid extraction method with organic solvents. Control (normal saline, 10 ml/kg), reference drug (furosemide 10 mg/kg) and three different doses (10 mg/kg, 50 mg/kg, 200 mg/kg) of the CEE and SRE were administered orally to male Wistar rats. The diuretic activity of the extracts was determined by measuring urine volume, urinary electrolyte and urine pH. The urine output measured at 5 h and 24 h, electrolyte concentration and pH were measured at 24 h duration. Data were analyzed by one way ANOVA followed by Dunnett's t-test. RESULTS: The findings indicated that the CEE significantly increased diuresis at 50 mg/kg and 200 mg/kg. Moreover, the SRE showed significant diuretic effect at all doses. CEE at a dose of 200 mg/kg increases the volume of urine by 81%, while SRE at a dose of 200 mg/kg increases the volume of urine by 114%. SRE demonstrated at 200 mg/kg the highest diuretic properties comparable to the reference drug. Na+, K+ and Cl- urinary excretion was also significantly increased at 50 mg/kg and 200 mg/kg of CEE and at all doses of SRE. HPLC analysis revealed the presence of the saponin aglycones, the main ones are medicagenic acid and oleanolic acid, their content in CEE 3.1 ± 0.4%, 2.4 ± 0.3% respectively and in SRE 7.9 ± 0.2%, 5.9 ± 0.3% respectively. Triterpenoid saponins could be responsible for the diuretic activity of Herniaria glabra. CONCLUSION: This study could make it useful to develop a pharmaceutical product based on purified saponin-rich extract of Herniaria glabra L. as a diuretic agent.

Identification by virtual screening and functional characterisation of novel positive and negative allosteric modulators of the α7 nicotinic acetylcholine receptor.

Several previous studies have demonstrated that the activity of neurotransmitters acting on ligand-gated ion channels such as the nicotinic acetylcholine receptor (nAChR) can be altered by compounds binding to allosteric modulatory sites. In the case of α7 nAChRs, both positive and negative allosteric modulators (PAMs and NAMs) have been identified and have attracted considerable interest. A recent study, employing revised structural models of the transmembrane domain of the α7 nAChR in closed and open conformations, has provided support for an inter-subunit transmembrane allosteric binding site (Newcombe et al 2017). In the present study, we have performed virtual screening of the DrugBank database using pharmacophore queries that were based on the predicted binding mode of PAMs to α7 nAChR structural models. A total of 81 compounds were identified in the DrugBank database, of which the 25 highest-ranked hits corresponded to one of four previously-identified therapeutic compound groups (carbonic anhydrase inhibitors, cyclin-dependent kinase inhibitors, diuretics targeting the Na+-K+-Cl- cotransporter, and fluoroquinolone antibiotics targeting DNA gyrase). The top-ranked compound from each of these four groups (DB04763, DB08122, furosemide and pefloxacin, respectively) was tested for its effects on human α7 nAChR expressed in Xenopus oocytes using two-electrode voltage-clamp electrophysiology. These studies, conducted with wild-type, mutant and chimeric receptors, resulted in all four compounds exerting allosteric modulatory effects. While DB04763, DB08122 and pefloxacin were antagonists, furosemide potentiated ACh responses. Our findings, supported by docking studies, are consistent with these compounds acting as PAMs and NAMs of the α7 nAChR via interaction with a transmembrane site.

Gallic acid, a phenolic compound isolated from Mimosa bimucronata (DC.) Kuntze leaves, induces diuresis and saluresis in rats.

Although present in the leaves of Mimosa bimucronata (DC.) and many other medicinal plants commonly used to augment urinary volume excretion, the effects of gallic acid as a diuretic agent remain to be studied. Wistar rats were orally treated with vehicle, hydrochlorothiazide, or gallic acid. The effects of gallic acid in the presence of hydrochlorothiazide, furosemide, amiloride, L-NAME, atropine, and indomethacin were also investigated. Diuretic index, pH, conductivity, and electrolyte excretion were evaluated at the end of the experiment (after 8 or 24 h). Gallic acid induced diuretic and saluretic (Na+ and Cl-) effects, without interfering with K+ excretion, when orally given to female and male rats at a dose of 3 mg/kg. These effects were associated with increased creatinine and conductivity values while pH was unaffected by any of the treatments. Plasma Na+, K+, and Cl- levels were not affected by any of the acute treatments. The combination with hydrochlorothiazide or furosemide was unable to intensify the effects of gallic acid when compared with the response obtained with each drug alone. On the other hand, the treatment with amiloride plus gallic acid amplified both diuresis and saluresis, besides to a marked potassium-sparing effect. Its diuretic action was significantly prevented in the presence of indomethacin, a cyclooxygenase inhibitor, but not with the pretreatments with L-NAME or atropine. Although several biological activities have already been described for gallic acid, this is the first study demonstrating its potential as a diuretic agent.

Development of drug discovery screening system by molecular interaction kinetics-mass spectrometry.

RATIONALE: Drug discovery studies invariably require qualitative and quantitative analyses of target compounds at every stage of drug discovery. We have developed a system combining molecular interaction analysis and mass spectrometry (LC-MS) using the principle of nanopore optical interferometry (nPOI) called molecular interaction kinetics-mass spectrometry (MIK-MS). Since nPOI has high binding capacity, the bond-dissociated compound can be directly detected using LC-MS. In this study, we use carbonic anhydrase II (CAII) as a ligand and apply six small compounds as analytes and report the affinity analysis using MIK-MS. METHODS: CAII was immobilized onto a COOH sensor chip using standard amine coupling. A reference surface was prepared by activating and subsequently blocking the surface under identical conditions. An amount of 50 µL of mix solution was injected over the reference channel and sample channel for CAII immobilization. The solutions eluting from the sensor chip were collected from the waste-line of the SKi Pro system every 30 s. Reconstructed elution samples were then injected into the LC-MS/MS system. RESULTS: A mixture containing furosemide, acetazolamide, 4-sulfamoylbenzoic acid, 5-(dimethylamino)-1-naphthalene sulfonamide (DNSA), sulfanilamide and sulpiride (15 µM each) was injected into the CAII-immobilized sensor chip, and the fractions eluted from the SKi Pro system were collected and subjected to selected reaction monitoring LC-MS characterization. Specific results were obtained for acetazolamide, DNSA, furosemide and sulpiride. The results suggest that the association-dissociation curve of a mixed sample can be obtained by one-time MIK-MS analysis. CONCLUSIONS: Six small-molecule binders of CAII were analyzed quantitatively using nPOI and MIK-MS, and the results were compared to published surface plasmon resonance (SPR) results. The nPOI and SPR results show good agreement, confirming the reliability of the analysis. Time-dependent binding results may be obtained by our MS sensorgram approach. Drugs that meet medical needs in a short period are required; this nPOI-LC-MS system is considered an important tool for rapid drug discovery.

Essential role of Kir5.1 channels in renal salt handling and blood pressure control.

Supplementing diets with high potassium helps reduce hypertension in humans. Inwardly rectifying K+ channels Kir4.1 (Kcnj10) and Kir5.1 (Kcnj16) are highly expressed in the basolateral membrane of distal renal tubules and contribute to Na+ reabsorption and K+ secretion through the direct control of transepithelial voltage. To define the importance of Kir5.1 in blood pressure control under conditions of salt-induced hypertension, we generated a Kcnj16 knockout in Dahl salt-sensitive (SS) rats (SSKcnj16-/-). SSKcnj16-/- rats exhibited hypokalemia and reduced blood pressure, and when fed a high-salt diet (4% NaCl), experienced 100% mortality within a few days triggered by salt wasting and severe hypokalemia. Electrophysiological recordings of basolateral K+ channels in the collecting ducts isolated from SSKcnj16-/- rats revealed activity of only homomeric Kir4.1 channels. Kir4.1 expression was upregulated in SSKcnj16-/- rats, but the protein was predominantly localized in the cytosol in SSKcnj16-/- rats. Benzamil, but not hydrochlorothiazide or furosemide, rescued this phenotype from mortality on a high-salt diet. Supplementation of high-salt diet with increased potassium (2% KCl) prevented mortality in SSKcnj16-/- rats and prevented or mitigated hypertension in SSKcnj16-/- or control SS rats, respectively. Our results demonstrate that Kir5.1 channels are key regulators of renal salt handling in SS hypertension.

Diuretic activity and toxicity study of the aqueous extract of Cola nitida seed on markers of renal function and electrolytes in rats.

BackgroundCola nitida is a plant, conventionally used in Africa in the treatment of various ailments such as migraine, morning sickness and indigestion. The aim of the present study was to explore the diuretic activity of the aqueous extract of C. nitida seed (AECONS) and alteration caused by its subchronic administration on the structure and function of the kidney of male Wistar rats. MethodsThe study was divided into diuretic and subchronic studies. Twenty-five male Wistar rats weighing between 140 and 180 g were divided into five groups of five rats each. The first 24 h of this study investigated the possible diuretic activity of C. nitida seed. Group I (the control) received 25 mL/kg of normal saline. Group II (the standard) received 20 mg/kg/day of furosemide. Groups III, IV, V received 400, 600 and 800 mg/kg/day of AECONS, respectively, and orally. Urine volume, pH, specific gravity and electrolytes were estimated in the samples of urine collected after 6 h of the study. From the second day onward and up to a period of 4 weeks, the rats in each group were given normal saline, furosemide and AECONS once daily as was done on the first day. At the end of the 4-week treatment period, blood and urine samples were collected for the determination of creatinine, urea, Na+, K+ and Cl- concentrations. Results The results of the diuretic study showed that the AECONS at all doses used and furosemide produced a significant increase in urine output with respect to the control group. AECONS also induced a significant increase in the urine concentrations of Na+, K+, Cl- in the experimental and standard groups when compared with the control group, except for group III which showed no significant variation in K+ concentration. In the subchronic study, AECONS caused a significant increase in the urine levels of Na+, K+, Cl- in the experimental and standard groups when compared with the control rats. The plasma Na+ concentration of groups IV and V was significantly lower than that of the control group. Photomicrographs of the kidneys of the experimental and standard groups revealed no significant alterations in the histology of their kidney tissues. Conclusions It is concluded that AECONS induced diuresis which is associated with increased Na+, K+ and Cl- loss in rats without any significant alteration in the structure of their kidneys.

Effects of Selective Agonists of V1a, V2, and V1b Receptors on Sodium Transport in Rat Kidney.

The role of subtypes of vasopressin receptors in modulation of renal sodium reabsorption was studied in in vivo experiments on Wistar rats. Selective V1a receptor agonist reduced sodium reabsorption in the kidneys and expression of these receptors increased by practically 100 times. This effect was similar to the effect of furosemide. Selective V2 receptor agonist enhanced sodium reabsorption in the kidney and simultaneously increased reabsorption of solute-free water. Stimulation of V1b receptors did not affect sodium transport. Our findings attest to the key role of V1a receptors in the regulation of renal excretion of sodium ions.

Acetazolamide enhances the release of urinary exosomal aquaporin-1.

BACKGROUND: Renal aquaporin-1 (AQP1), a water channel protein, is known to be secreted into urine, conveyed by nano-sized extracellular vesicles called exosomes. A previous study has demonstrated that acetazolamide (AZ), a diuretic that inhibits carbonic anhydrases, alters the expression level of AQP1 in cultured cells. Here we investigated whether AZ alters the release of urinary exosomal AQP1 in vivo. METHODS: The effect of AZ on urinary exosomal AQP1 secretion was examined in rats and compared with furosemide (another diuretic), NaHCO3 (an alkalizing agent) and NH4Cl (an acidifying agent). Urine, blood and kidney samples were obtained 2 h after each treatment. Urinary exosomes were isolated by a differential centrifugation technique and urinary exosomal proteins were analyzed by immunoblotting. RESULTS: The release of exosomal AQP1 into urine was markedly increased after treatment with AZ, accompanied by alkaluria and metabolic acidosis. Immunohistochemistry clearly demonstrated that AZ increased the apical membrane expression of AQP1 in the proximal tubules. AZ did not affect the release of exosomal marker proteins (tumor susceptibility gene 101 protein and apoptosis-linked gene 2 interacting protein X). Treatment with furosemide did not change, whereas NaHCO3 and NH4Cl decreased the exosomal release of AQP1. CONCLUSION: The present findings indicate that AZ increases the release of exosomal AQP1 into urine in association with enhanced apical membrane expression of AQP1.

The role of calbindin-D28k on renal calcium and magnesium handling during treatment with loop and thiazide diuretics.

Calbindin-D28k (CBD-28k) is a calcium binding protein located in the distal convoluted tubule (DCT) and plays an important role in active calcium transport in the kidney. Loop and thiazide diuretics affect renal Ca and Mg handling: both cause Mg wasting, but have opposite effects on Ca excretion as loop diuretics increase, but thiazides decrease, Ca excretion. To understand the role of CBD-28k in renal Ca and Mg handling in response to diuretics treatment, we investigated renal Ca and Mg excretion and gene expression of DCT Ca and Mg transport molecules in wild-type (WT) and CBD-28k knockout (KO) mice. Mice were treated with chlorothiazide (CTZ; 50 mg · kg(-1) · day(-1)) or furosemide (FSM; 30 mg · kg(-1) · day(-1)) for 3 days. To avoid volume depletion, salt was supplemented in the drinking water. Urine Ca excretion was reduced in WT, but not in KO mice, by CTZ. FSM induced similar hypercalciuria in both groups. DCT Ca transport molecules, including transient receptor potential vanilloid 5 (TRPV5), TRPV6, and CBD-9k, were upregulated by CTZ and FSM in WT, but not in KO mice. Urine Mg excretion was increased and transient receptor potential subfamily M, member 6 (TRPM6) was upregulated by both CTZ and FSM in WT and KO mice. In conclusion, CBD-28k plays an important role in gene expression of DCT Ca, but not Mg, transport molecules, which may be related to its being a Ca, but not a Mg, intracellular sensor. The lack of upregulation of DCT Ca transport molecules by thiazides in the KO mice indicates that the DCT Ca transport system is critical for Ca conservation by thiazides.

Evaluation of the diuretic effects of crude stem bark extraction of Zanthoxylum heitzii (Rutaceae) in Wistar rats.

OBJECTIVE: Zanthoxylum heitzii is a medicinal plant widely used in central Africa for the treatment of many diseases, especially cardiovascular diseases and hypertension. The diuretic effects of crude stem bark extraction were determined and its safety in rats was evaluated. METHODS: The diuretic effects of crude stem bark extraction of Z. heitzii 250 g ± 10 g) of both sexes. The crude stem bark extraction of Z. heitzii at the doses of 225, 300 and 375 mg/kg was administered to rats at 5 mL/kg body weight. Urine volume was determined 1, 2, 3, 4, 5, 6 and 24 h after administration of the extract. Kinetics of electrolyte elimination in response to a single oral administration dose of acute treatment was measured. The experiments were performed under the same conditions with two synthetic pharmacological diuretics considered as reference (furosemide and hydrochlorothiazide). Urinary and plasma concentrations of sodium and potassium ions were determined using flame photometry. Concentrations of creatinine, urea, glucose, albumin and electrolytes in the plasma and urine samples were evaluated using a two-way digital bidirectional spectrophotometer. The osmolarity of plasma and urine samples was measured by cytometry using an osmometer. Aldosterone was measured by radioimmunoassay. RESULTS: The plant extract accelerated the elimination of overloaded fluid and increased urine volume and the excretion of Na+, K+ and Cl- 24 h after administration (P<0.05). The increase in elimination of Na+, K+, and Cl- induced by caused alkalinization of the urine, and showed a strong inhibitory effect on carbonic anhydrase and saluretic. These effects were mainly observed at the dose of 375 mg/kg. At the maximum diuretic response, urinary osmolarity decreased significantly (P<0.05) when compared to controls. The stability of aldosterone level, the absence of correlation with the plasma levels of Na+, and increased clearance of free water in the animals treated with indicated that increased diuresis and natriuresis were tubular in origin. No significant (P>0.05) changes were observed in the body temperature of the animals. CONCLUSION: The significant increase in urine volume 24 h after treatment followed a dose-response pattern. The excretion of Na+, K+ and Cl- caused a decrease in urine osmolarity. The stability of aldosterone, the absence of correlation with the plasma levels of sodium, and increased clearance of free water in animals treated with aqueous extract suggest that increased diuresis and moderate natriuresis elevation were of tubular origin.

Salt-sparing diuretic action of a water-soluble urea analog inhibitor of urea transporters UT-A and UT-B in rats.

Inhibitors of kidney urea transporter (UT) proteins have potential use as salt-sparing diuretics ('urearetics') with a different mechanism of action than diuretics that target salt transporters. To study UT inhibition in rats, we screened about 10,000 drugs, natural products and urea analogs for inhibition of rat UT-A1. Drug and natural product screening found nicotine, sanguinarine and an indolcarbonylchromenone with IC50 of 10-20 µM. Urea analog screening found methylacetamide and dimethylthiourea (DMTU). DMTU fully and reversibly inhibited rat UT-A1 and UT-B by a noncompetitive mechanism with IC50 of 2-3 mM. Homology modeling and docking computations suggested DMTU binding sites on rat UT-A1. Following a single intraperitoneal injection of 500 mg/kg DMTU, peak plasma concentration was 9 mM with t1/2 of about 10 h, and a urine concentration of 20-40 mM. Rats chronically treated with DMTU had a sustained, reversible reduction in urine osmolality from 1800 to 600 mOsm, a 3-fold increase in urine output, and mild hypokalemia. DMTU did not impair urinary concentrating function in rats on a low protein diet. Compared to furosemide-treated rats, the DMTU-treated rats had greater diuresis and reduced urinary salt loss. In a model of syndrome of inappropriate antidiuretic hormone secretion, DMTU treatment prevented hyponatremia and water retention produced by water-loading in dDAVP-treated rats. Thus, our results establish a rat model of UT inhibition and demonstrate the diuretic efficacy of UT inhibition.

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.

Diuretic effect of alkaloids fraction extracted from Selaginella lepidophylla (Hook. et Grev.) Spring / Efecto diurético de la fracción con contenido de alcaloides extraída deSelaginella lepidophylla (Hook. et Grev.) Spring

The aerial parts of Selaginella lepidophylla (Hook. et Grev.) Spring, are used in Mexican folk medicine to treat renal diseases. The aim of this study was to measure the diuretic response of an aqueous extract (200 mg/kg) and alkaloids fraction at different doses (10, 40 y 100 mg/kg) of this plant and compare it with that induced by furosemide (4 mg/kg). Extract, alkaloids fraction, furosemide and vehicle were administered orally to adult rats and the effects in sodium, potassium and water balance were measured. The extract, the alkaloids fraction and the furosemide produced important and significant increments in urinary excretion of sodium, potassium and water with respect to control group. This increment was dose dependent of the alkaloids fraction, the highest dose produced a major effect. Potassium excretion increased but it was less than the one induced by furosemide. These results suggest that the aqueous extract and rich fraction in alkaloids from S. lepidophylla induce diuretic response.

Las partes aéreas de Selaginella lepidophylla (Hook. et Grev.) Spring, son usadas en la medicina tradicional mexicana para tratar enfermedades renales. El objetivo del estudio fue medir la respuesta diurética de un extracto acuoso (200 mg/kg) y de diferentes dosis de la fracción de alcaloides (10, 40 y 100 mg/kg) de esta planta y compararla con la inducida por furosemida (4 mg/kg). El extracto, la fracción de alcaloides, la furosemida y el vehículo fueron administrados por vía oral a ratas adultas y se midieron los efectos en el balance de sodio, potasio e hídrico. El extracto, la fracción de alcaloides y la furosemida produjeron importantes y significativos incrementos en la excreción urinaria de sodio, potasio y agua con respecto al grupo testigo. Este incremento fue dependiente de la dosis de la fracción de alcaloides, la dosis más alta produjo el mayor efecto. El incremento en la excreción de potasio fue menor al de furosemida. Los resultados sugieren que el extracto acuoso y la fracción rica en alcaloides de S. lepidophylla inducen una respuesta diurética.

[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.

Effect of NSAIDs and diuretics on nephrogenesis in an ex vivo embryogenic kidney model.

The kidney is one of the key organs in clearing foreign compounds. The effects of drugs on the developing kidney are relatively unknown. We studied the direct effect of furosemide, hydrochlorothiazide, ibuprofen, and indomethacin on kidney development in an ex vivo embryonic kidney model. At embryonic day 13, metanephroi were dissected from mice and cultured in control media or media supplemented with various clinically relevant concentrations of drugs. The ureteric tree was visualized by whole-mount staining and branching was evaluated by counting. Additionally, gene expression levels of Wt1, Sox9, Bmp7, Fgf8, and Gdnf were investigated. No distinct differences were noted on either ureteric tip development or gene expression analysis for each drug after 24 hr of exposure. Even though short-term exposure to clinically relevant concentrations seems not to disturb renal development, future research is needed to study prolonged or repeated exposures.