The chemical profiling of aqueous soluble fraction from Lagopsis supina and its diuretic effects via suppression of AQP and RAAS pathways in saline-loaded rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Lagopsis supina (Steph.) Ik. -Gal. ex Knorr. has been widely used as a remedy treatment for diuresis and edema in China over 2500 years. Our previous results showed that the aqueous soluble fraction from L. supina (LSB) possessed acute diuretic effect. AIM OF THE STUDY: The aim of this study was to appraise the acute (6 h) and prolonged (7 d) diuretic effects, underlying mechanisms, and chemical profiling of LSB. MATERIALS AND METHODS: The chemical profiling of LSB was performed by ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UHPLC-qTOF-MS/MS). Then, oral administration of LSB (40, 80, 160 and 320 mg/kg) and furosemide (10 mg/kg) once daily for 7 consecutive days to evaluate the diuretic effects in saline-loaded rats. The body weight, food consumption, and water intake were recorded once daily. The urinary volume, pH and electrolyte concentrations (Na+, K+, Cl-, and Ca2+) were measured after administration drugs for acute and prolonged diuretic effects. In addition, the serum levels of Na+-K+-ATPase, angiotensin II (Ang II), anti-diuretic hormone (ADH), aldosterone (ALD), atriopeptin (ANP), aquaporins (AQPs)-1, 2 and 3 were determined by ELISA kits. The mRNA expressions and protein levels of AQPs-1, 2 and 3 were analyzed by real-time quantitative PCR and Western blot assays, respectively. RESULTS: 30 compounds were identified in LSB based on accurate mass and MS/MS fragmentation compared to literature, among which phenylpropanoids and flavonoids could be partly responsible for the major diuretic effect. Daily administration of LSB (160 or 320 mg/kg) prominently increased urinary excretion volume after the 2 h at the first day of treatment, remaining until the 7th day. LSB did not cause Na+ and K+ electrolyte abnormalities, and has minor effect on Cl- and Ca2+ concentrations at 320 mg/kg. Furthermore, LSB observably suppressed renin-angiotensin-aldosterone system (RAAS) activation, including decreased serum levels of Ang II, ADH, and ALD, and prominently increased serum level of ANP in rats. LSB treatment significantly down-regulated the serum levels, mRNA expressions and protein levels of AQP1, AQP2, and AQP3. CONCLUSION: LSB has a prominent acute and prolonged diuretic effects via suppression of AQP and RAAS pathways in saline-loaded rats, and support the traditional folk use of this plant. Taken together, LSB might be a potential diuretic agent.

Stripping voltammetric determination of indapamide in serum at castor oil-based carbon paste electrodes.

The diuretic drug indapamide has been characterized voltammetrically at carbon paste electrodes by means of cyclic and differential pulse voltammetry. An adsorptive stripping method at carbon paste electrode modified with castor oil for trace determination of indapamide was described. A study of the variation of the peak current with solution variables such as pH, ionic strength, concentration of indapamide, possible interference, and instrumental variables such as scan rate, pulse amplitude, preconcentration time, accumulation potential, paste composition has resulted in the optimization of the oxidation signal for analytical purposes. By anodic stripping differential pulse voltammetry, the calibration plot was linear in the range 5 x 10(-8) x 10(-7) M with a detection limit of 5 x 10(-9) M at carbon paste electrode modified with castor oil in pH 4.0. The preconcentration medium-exchange approach was utilized for selective determination of indapamide in spiked serum. A detection limit of 15 ng ml(-1) was obtained for dilute serum sample after 3 min accumulation and medium-exchange procedure.

Suppression of rat hepatic cytochrome P450s by protein-calorie malnutrition: complete or partial restoration by cysteine or methionine supplementation.

Pharmacokinetic profiles of therapeutic agents are altered by protein-calorie malnutrition (PCM). The current study was designed to determine the expression of hepatic cytochrome P450s in rats after protein restriction and to investigate its molecular basis. Western blot analysis revealed that rats with protein restriction for 4 weeks exhibited marked suppression in the hepatic P450 1A2, 2C11, 2E1, and 3A1/2 levels. Northern blot analysis showed that hepatic P450 1A2, 2C11, and 3A1/2 mRNAs were significantly decreased in the state of PCM. The P450 2E1 mRNA level was slightly decreased in PCM rats, suggesting the possibility that expression of P450 2E1 affected by PCM might result from the transcriptional and/or posttranscriptional regulation. PCM-induced changes in most P450 expression completely or partially returned to control levels by a week of cysteine supplementation. Cysteine also prevented decreases in P450 1A2, 2C11, 2E1, and 3A1/2 mRNA levels by PCM. Methionine was minimally active in restoring the P450 expression. A metabolic change in hepatic ethoxyresorufin dealkylase activity in PCM rats was consistent with the P450 apoprotein and mRNA levels. Although the plasma concentrations of azosemide, a loop diuretic, primarily metabolized by cytochrome P450 1A, increased in protein-deprived rats, cysteine supplementation significantly reduced the increased plasma concentrations of the drug. The altered pharmacokinetic parameters of azosemide in PCM rats returned to those of control after cysteine supplementation, corroborating the conclusion that cysteine was effective in restoring cytochrome P450 expression and metabolic activities.

[Surreptitious intake of diuretics as the cause of pseudo-Bartter's syndrome: apropos of a case and differential diagnosis]. / Ingesta subrepticia de diuréticos como causa de "Pseudo-Síndrome Bartter", a propósito de un caso y diagnóstico diferencial.

We describe a 39 years old patient with a history of chronic symptomatic hypokalemia. She denied taking any drugs. She satisfied the clinical criteria for Bartter's syndrome and more precisely for Gitelman's syndrome: hypokalemia in the presence of inappropriately high potassium excretion, metabolic alkalosis, hyperreninemic hyperaldosteronism, hypomagnesemia with inappropriately high magnesium excretion, normocalcemia, hypocalciuria and normal blood pressure. A HPLC analysis detected the presence of furosemide in urine and chlorthalidone in urine and plasma samples. After the self administration of diuretics was stopped, the above alterations came back to normality. Prior to the verification of a self administration of diuretics, the patient showed clinical and biochemical parameters that oriented to surreptitious diuretic ingestion (Pseudo-Bartter's syndrome) not to Bartter's syndrome or Gitelman's syndrome, particularly the plasma potassium readily restored to normal by the administration of potassium chloride supplements, the increased plasma uric acid with low uric acid fractional clearance, the widely different urine and plasma electrolyte levels and the presence psychiatric disorders. The literature is reviewed and differential diagnosis, among this three syndromes, is made.

Effects of indapamide on atherosclerosis development in cholesterol-fed rabbits.

We examined the effect of indapamide (IND) on the development of atherosclerosis lesions in rabbits maintained on a 1% (wt/wt) cholesterol-enriched diet for a 16-week period. IND was supplemented to the diet at three different levels to correspond to doses of 0.1, 0.3, and 1 mg/kg/day. Throughout the treatment, dietary consumption and body weight gains were comparable among the experimental and control groups. IND had no significant effect on plasma cholesterol, triglycerides, or phospholipids concentrations. Despite the lack of effect of the drug on these parameters, its administration produced a tendency toward a reduction in the aortic content of cholesterol and a dose-dependent and significant decrease in aortic damage. In the aortic arch, the extent of intimal aortic surface covered by grossly discernible atherosclerotic lesions was decreased by IND 1 mg/kg/day from 11.02 +/- 1.10 to 6.00 +/- 1.00% (p < 0.05) and from 9.72 +/- 1.39 to 5.37 +/- 1.20% (p < 0.05) in the remaining thoracic sections. In addition, the former dose also reduced the number of lesions per square centimeter from 3.69 +/- 0.68 to 1.72 +/- 0.53% (p < 0.05), and from 3.37 +/- 0.85 to 1.55 +/- 0.46% (p < 0.05) in aortic arch and in thoracic sections, respectively. The possibility that IND reduces the development of atherosclerotic lesions produced by diet-induced hypercholesterolemia through a mechanism involving its calcium antagonist and/or its antioxidant activity is discussed.