Rhanany Alan Calloi Palozi

Effects of Angiotensin-Converting Enzyme Inhibitor Derived from Tropaeolum majus L. in Rat Preimplantation Embryos: Evidence for the Dehydroepiandrosterone and Estradiol Role

Although several studies have shown the inhibitory effects of Tropaeolum majus extracts (HETM) on angiotensin-converting enzyme (ACE) activity, no studies have been carried out during the beginning of pregnancy, when humoral and hormonal imbalance may affect zygote and early embryo transport. This study investigates whether HETM can affect embryonic development when administered during the one-cell-blastocyst period. Pregnant Wistar rats received orally the HETM (3, 30, and 300u2009mg/kg/day) from the 1st to the 7th gestational day. Rats were killed on the 8th day of pregnancy and the following parameters were evaluated: clinical symptoms of toxicity (including organ weights), number of corpora lutea, implants per group, preimplantation losses ratio, and the serum levels of dehydroepiandrosterone (DHEA), estradiol, and progesterone. No clinical symptoms of maternal toxicity were evidenced. On the 8th day of pregnancy, the levels of DHEA and estradiol were increased and significant preimplantation losses were observed at all doses used. The present study reveals that the HETM can raise levels of DHEA and estradiol and induce difficulty in the embryo implantation in the early stages of pregnancy. The data contributes significantly to the safety aspects of using this natural product when trying to get pregnant or during pregnancy.

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

ETHNOPHARMACOLOGICAL RELEVANCEnAlthough 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.nnnAIMnTo investigate the possible cardiorenal effects of an herbal preparation obtained from L. divaricata leaves.nnnMATERIALS AND METHODSnFirst, 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.nnnRESULTSnAnalyses 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.nnnCONCLUSIONnThe 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.

Ethnopharmacological investigations of the cardio-renal properties of a native species from the region of Pantanal, state of Mato Grosso do Sul, Brazil

ETHNOPHARMACOLOGICAL RELEVANCEnAcanthospermum hispidum DC. is an important medicinal herb that belongs to family Asteraceae, popularly used as a diuretic and hypotensive in the region of Pantanal, state of Mato Grosso do Sul, Brazil. Despite the relevance of this species throughout the country, there are no detailed studies about its possible ethnobotanical indication.nnnAIMnTo carry out a detailed ethnopharmacological investigation of the cardio-renal properties of A. hispidum.nnnMATERIALS AND METHODSnFirst, a detailed morpho-anatomical study with the purpose of characterizing and providing quality control parameters for the species was carried out. Then, purified aqueous extract (ESAH) was obtained and a detailed phytochemical investigation about its main secondary metabolites was performed. In addition, a thorough acute toxicological study was conducted to evaluate the actual toxic effects of this preparation. Finally, the possible diuretic and hypotensive effects of ESAH on male Wistar rats (30, 100, 300mg/kg; intraduodenally) were evaluated, and using pharmacological antagonists or inhibitors, the involvement of prostaglandin/cAMP and nitric oxide/cGMP pathway and potassium channels in ESAH-induced hypotension was investigated.nnnRESULTSnThe analyses performed by liquid chromatography-mass spectrometry showed that the main secondary metabolites present in ESAH were phenolic compounds, such as caffeoylquinic acids (chlorogenic acid), dicaffeoylquinic acids and glycosylated flavonoids (quercetin glucoside and galactoside). ESAH did not induce any acute toxic effects and did not affect the urinary volume or renal excretion of electrolytes in Wistar rats. On the other hand, intraduodenal administration of ESAH induces a significant acute hypotensive effect. Previous treatment with N(G)-nitro-L-arginine methyl ester, methylene blue, or tetraethylammonium fully avoided the hypotensive effect of ESAH. All other parameters were not affected by treatment with ESAH.nnnCONCLUSIONnData obtained in this study allow us to suggest that ESAH obtained from A. hispidum presents an important acute hypotensive effect, which appears to be dependent on the nitric oxide/cGMP pathway. This study presents new evidences about the therapeutic potential of this species when acute hypotensive response is required.

Roles of Nitric Oxide and Prostaglandins in the Sustained Antihypertensive Effects of Acanthospermum hispidum DC. on Ovariectomized Rats with Renovascular Hypertension

Although Acanthospermum hispidum is used in Brazilian folk medicine as an antihypertensive, no study evaluated its effects on a renovascular hypertension and ovariectomy model. So, this study investigated the mechanisms involved in the antihypertensive effects of an ethanol-soluble fraction obtained from A. hispidum (ESAH) using two-kidney-one-clip hypertension in ovariectomized rats (2K1C plus OVT). ESAH was orally administered at doses of 30, 100, and 300u2009mg/kg, daily, for 28 days, after 5 weeks of surgery. Enalapril (15u2009mg/kg) and hydrochlorothiazide (25u2009mg/kg) were used as standard drugs. Diuretic activity was evaluated on days 1, 7, 14, 21, and 28. Systolic, diastolic, and mean blood pressure and heart rate were recorded. Serum creatinine, urea, thiobarbituric acid reactive substances, nitrosamine, nitrite, aldosterone, vasopressin levels, and ACE activity were measured. The vascular reactivity and the role of nitric oxide (NO) and prostaglandins (PG) in the vasodilator response of ESAH on the mesenteric vascular bed (MVB) were also investigated. ESAH treatment induced an important saluretic and antihypertensive response, therefore recovering vascular reactivity in 2K1C plus OVT-rats. This effect was associated with a reduction of oxidative and nitrosative stress with a possible increase in the NO bioavailability. Additionally, a NO and PG-dependent vasodilator effect was observed on the MEV.

Celosia argentea L. (Amaranthaceae) a vasodilator species from the Brazilian Cerrado – An ethnopharmacological report

ETHNOPHARMACOLOGICAL RELEVANCEnCelosia argentea L. (Amaranthaceae), popularly known as crista de galo, is used in folk medicine due to its diuretic and hypotensive effects. However, there are no reports in the literature regarding its pharmacological effects on the cardiovascular system as well as no data proving the safety of this species.nnnAIMnTo perform a detailed ethnopharmacological investigation of the ethanol soluble fraction from C. argentea (ESCA) using male and female Wistar rats.nnnMATERIAL AND METHODSnFirstly, a morpho-anatomical characterization was performed to determine the quality control parameters for the identification of the species under investigation. Then, the ethanol extract was obtained and chemically characterized by LC-DAD-MS. Furthermore, an oral acute toxicity study was performed in female Wistar rats. Finally, the possible diuretic and hypotensive effects of three different doses of ESCA (30, 100 and 300u202fmg/kg) were evaluated in male Wistar rats. Besides, the vasodilatory response of ESCA in mesenteric vascular beds (MVBs) and its involvement with nitric oxide/cGMP and prostaglandin/cAMP pathways as well as potassium channels were evaluated.nnnRESULTSnThe main secondary metabolites present in ESCA were phenolic compounds, megastigmanes and triterpenoid saponins. ESCA caused no toxic effects in female rats nor increased urinary excretion in male rats after acute administration. However, ESCA significantly increased the renal elimination of potassium and chloride, especially at the end of 24u202fh after administration. Intermediary dose (100u202fmg/kg) of ESCA was able to promote significant acute hypotension and bradycardia. Moreover, its cardiovascular effects appear to be involved with the voltage-dependent K+ channels activation in MVBs.nnnCONCLUSIONnThis study has brought new scientific evidence of preclinical efficacy of C. argentea as a hypotensive agent in normotensive rats. Apparently, these effects are involved with the activation of the voltage-sensitive K+ channels contributing to the reduction of peripheral vascular resistance and cardiac output.

Redox regulation and NO/cGMP plus K+ channel activation contributes to cardiorenal protection induced by Cuphea carthagenensis (Jacq.) J.F. Macbr. in ovariectomized hypertensive rats

BACKGROUNDnOne of the medicinal plants widely used by the population in the treatment of hypertension, atherosclerosis and circulatory disorders is Cuphea carthagenensis (Jacq.) J.F. Macbr. (Lythraceae), popularly known as sete sangrias, being found in Brazil, Hawaii and in South Pacific Islands. Despite the widespread use of this species by the population, its long-term antihypertensive and cardioprotective activities have not yet been scientifically evaluated.nnnPURPOSEnTo evaluate the possible cardioprotective effects of an ethanol-soluble fraction obtained from C. carthagenensis (ESCC) using ovariectomized hypertensive rats to simulate a broad part of the female population over 50 years of age affected by hypertension. In addition, the molecular mechanism that may be responsible for its cardiorenal protective effects was also explored.nnnMETHODSnFemale Wistar rats were submitted to surgical procedures of bilateral ovariectomy and induction of renovascular hypertension (two-kidneys, one-clip model). The sham-operated group was used as negative control. ESCC was obtained and a detailed phytochemical investigation about its main secondary metabolites was performed. ESCC was orally administered at doses of 30, 100 and 300 u202fmg/kg, daily, for 28 days, 5 weeks after surgery. Enalapril (15u202fxa0mg/kg) was used as standard antihypertensive drug. Renal function was evaluated on days 1, 7, 14, 21 and 28. At the end of the experimental period, systolic, diastolic, mean arterial pressure and heart rate were recorded. The activity of the tissue enzymatic antioxidant system, thiobarbituric acid reactive substances, nitrotyrosine, nitrite, aldosterone and vasopressin levels, in addition to the activity of the angiotensin-converting enzyme were also evaluated. Additionally, vascular reactivity to acetylcholine, sodium nitroprusside, and phenylephrine, and the role of nitric oxide, prostaglandins, and K+ channels in the vasodilator response of ESCC on the mesenteric vascular bed were also investigated.nnnRESULTSnESCC-treatment induced an important cardiorenal protective response, preserving renal function and preventing elevation of blood pressure and heart rate in ovariectomized hypertensive rats. In addition, prolonged treatment with ESCC recovered mesenteric vascular reactivity at all doses used. This effect was associated with an important modulation of the antioxidant defense system with a possible increase in NO bioavailability. Additionally, NO/cGMP activation and K+ channel opening-dependent vasodilator effect was observed on the mesenteric vascular bed, indicating a potential mechanism for the cardiovascular effects of ESCC.nnnCONCLUSIONnA 28-days ESCC treatment reduces the progression of the cardiorenal disease in ovariectomized hypertensive rats. These effects seem to be involved with an attenuation of oxidative and nitrosative stress, affecting endothelial nitric oxide production and K+ channel opening in smooth muscle cells.

Influence of Luehea divaricata Mart. extracts on peripheral vascular resistance and the role of nitric oxide and both Ca +2 -sensitive and Kir6.1 ATP-sensitive K+ channels in the vasodilatory effects of isovitexin on isolated perfused mesenteric beds

BACKGROUNDnLuehea divaricata Mart. (Malvaceae) is an important medicinal species widely used by indigenous and riverside populations of the Brazilian Pantanal region. It has been shown that the several extracts obtained from leaves of this species have important cardioprotective effects. Nevertheless, the secondary metabolites responsible for this activity, as well as the molecular mechanisms responsible for their pharmacological effects remain unknown.nnnPURPOSEnTo carry out a biomonitoring study to identify possible active metabolites present in different ESLD fractions and evaluate the mechanisms responsible for the vasodilatory effects on isolated perfused mesenteric beds.nnnMETHODSnFirst, ESLD was obtained from L. divaricata leaves and a liquid-liquid fractionation was performed. The resulting fractions were analyzed by liquid chromatography-mass spectrometry. Then, the possible vasodilatory effects of ESLD, chloroform, ethyl acetate, n-butanolic and aqueous fractions on perfused arterial mesenteric vascular beds were evaluated. Finally, the molecular mechanisms involved in vasodilator responses of the aqueous fraction and its chemical component, isovitexin, on the mesenteric arteriolar tone were also investigated.nnnRESULTSnIn preparations with functional endothelium ESLD, n-butanolic, aqueous fraction and isovitexin dose-dependently reduced the perfusion pressure in mesenteric vascular beds. Endothelium removal or inhibition of nitric oxide synthase enzymes by L-NAME reduced the vasodilatory effects induced by aqueous fraction and isovitexin. Perfusion with nutritive solution containing 40xa0mM KCl abolished the vasodilatory effect of all aqueous fractions and Isovitexin doses. Treatment with glibenclamide, a Kir6.1 (ATP-sensitive) potassium channels blocker, tetraethylammonium, a non-selective KCa (calcium-activated) potassium channels blocker, or apamin, a potent blocker of small conductance Ca2+-activated (SK KCa) potassium channels reduced by around 70% vasodilation induced by all aqueous fractions and isovitexin doses. In addition, association of tetraethylammonium and glibenclamide, or L-NAME and glibenclamide, fully inhibited aqueous fraction and Isovitexin -induced vasodilation.nnnCONCLUSIONnThis study showed that AqueFr obtained from Luehea divaricata and its metabolite - isovitexin - has important vasodilatory effects on MVBs. Apparently, these effects are dependent on endothelium-NO release and both SK KCa K+ channels and Kir6.1 ATP-sensitive K+ channels activation in the vascular smooth muscle.

Biological Characterization of an Edible Species from Brazilian Biodiversity: From Pharmacognostic Data to Ethnopharmacological Investigation

Abstract Talisia esculenta (A. St.-Hil.) Radlk. is a large tree belonging to family Sapindaceae and popularly known as “pitombeira” or “pitomba.” Although species have relevant economic and medicin...Talisia esculenta (A. St.-Hil.) Radlk. is a large tree belonging to family Sapindaceae and popularly known as pitombeira or pitomba. Although species have relevant economic and medicinal uses in Brazil, no study has investigated its effectiveness as a diuretic, hypotensive, and antihypertensive agent. The aim of this study was to present a detailed anatomical and histochemical study for T. esculenta and provide important safety and efficacy parameters. After morpho-anatomical and microchemical study, a purified aqueous extract (ethanol soluble fraction obtained from T. esculenta [ESTE]) was obtained, and detailed phytochemical investigation was performed. Subsequently, acute oral toxicity test was performed in male and female rats. Moreover, diuretic, hypotensive, and antihypertensive effects on normotensive and spontaneously hypertensive rats (SHR) were investigated. Finally, the effects of prolonged treatment with ESTE on serum levels of nitrite, thiobarbituric acid reactive species, and nitrotyrosine were also measured in SHR. Oral treatment with ESTE did not induce acute toxic effects and did not affect urine production, blood pressure, or heart rate of normotensive and SHR. Prolonged treatment with ESTE was able to increase serum nitrite levels and significantly reduce oxidative and nitrosative stress markers in SHR. Data obtained showed that ESTE has a significant antioxidant activity without showing any clinical signs of acute toxicity. The use of this species as a diuretic, hypotensive, or antihypertensive agent should be carried out with caution, since administration in rodents did not produce renal and/or hemodynamic responses that justify this indication.

Biomonitoring the cardiorenal effects of Luehea divaricata Mart.: An ethnoguided approach

ETHNOPHARMACOLOGICAL RELEVANCEnLuehea divaricata Mart. (Malvaceae) is an important medicinal species that is widely used as a diuretic in the Brazilian Pantanal region. An ethanolic supernatant that was obtained from an infusion of leaves of this species (ESLD) was recently shown to exert hypotensive and diuretic activity. Nevertheless, the secondary metabolites that are responsible for this activity and the molecular mechanisms of pharmacological action remain unknown.nnnAIMnWe performed a detailed study to identify possible active metabolites that are present in different ESLD fractions and investigated their effects on renal and peripheral arteriolar tone. We further evaluated their interrelations with sustained diuretic and hypotensive actions.nnnMATERIALS AND METHODSnThe ESLD was first obtained from L. divaricata leaves, and liquid-liquid fractionation was performed. The fractions were analyzed by liquid chromatography-mass spectrometry. An ethyl acetate fraction (AceFr), n-butanolic fraction (ButFr), and aqueous fraction (AqueFr) were then orally administered in male Wistar rats in a single dose or daily for 7 days. The doses were previously defined based on the yield that was obtained from each fraction. Hydrochlorothiazide was used as a positive control. Blood pressure, heart rate, urinary volume, pH, density, and urinary sodium, potassium, chloride, and calcium levels were measured. Serum levels of nitrite, thiobarbituric acid reactive species, nitrotyrosine, aldosterone, vasopressin, and plasma angiotensin converting enzyme activity were also measured. Finally, the direct effects of the ButFr on renal and mesenteric arteriolar tone and the role of nitric oxide and prostaglandins in the renal and hemodynamic effects were investigated.nnnRESULTSnOf the fractions that were tested, only the ButFr exerted significant diuretic and saluretic effects. The AceFr and ButFr also had acute hypotensive effects, but only the ButFr maintained its response after 7 days of treatment. Prolonged treatment with the ButFr increased serum nitrite levels and significantly reduced oxidative and nitrosative markers of stress. Additionally, the ButFr caused a vasodilatory response in the renal and mesenteric arteriolar beds through the release of nitric oxide and prostaglandins. Finally, the diuretic and hypotensive effects of the ButFr were completely blocked by pretreatment with Nω-nitro-L-arginine methyl ester and indomethacin, thus demonstrating the direct involvement of nitric oxide and prostaglandins in these effects.nnnCONCLUSIONnThe ButFr that was obtained from Luehea divaricata exerted sustained diuretic and hypotensive effects. These effects were apparently attributable to the release of nitric oxide and prostaglandins, which reduce renal and peripheral arteriolar tone and lead to an increase in the glomerular filtration rate and a reduction of global peripheral resistance. These findings suggest that the ButFr may be a potential complementary therapy for several conditions in which diuretic and hypotensive effects are required.

Diuretic herb Gomphrena celosioides Mart. (Amaranthaceae) promotes sustained arterial pressure reduction and protection from cardiac remodeling on rats with renovascular hypertension

ETHNOPHARMACOLOGICAL RELEVANCEnGomphrena celosioides Mart., belonging to the Amaranthaceae family, is a weed known as perpétua, and its ethnopharmacological use is to treat of urinary tract disorders and kidney stones. Urinary tract disorders and kidney stones could include several pathological conditions such hypertension, diuretic and lithiasic problems. In the present work a model of renovascular hypertension was developed in vivo to investigate its usefulness as an antihypertensive drug.nnnAIM OF THE STUDYnEvaluate the effect of acute and 28 day oral administration of G. celosioides extract on systemic arterial pressure and diuresis of renovascular-hypertensive rats, as well as its effect on cardiac remodeling and vascular reactivity.nnnMATERIALS AND METHODSnEthanolic extract of G. celosioides (EEGC) was used. To induce renovascular hypertension, adult male Wistar rats were submitted to Goldblatt 1K1C or 2K1C surgery. The mean arterial pressure (MAP) of 1K1C animals was directly assessed by cannulation of the carotid artery before and after intraduodenal acute administration of 30, 100 or 300u202fmg/kg of EEGC. For the 4-week assay, 2K1C animals received daily treatments with water (control group), 100u202fmg/kg EEGC or 15u202fmg/kg enalapril for 28 days. Diuresis and caudal blood pressure were assessed weekly, and at the 28th day of treatment, the MAP was directly quantified shortly before euthanasia. Internal organs were removed, weighed and routinely processed for histology and the left ventricle wall was measured. Blood was collected for biochemical analysis and mechanism investigation by quantification of angiotensin converting enzyme (ACE) activity and aldosterone, nitrite and thiobarbituric acid reactive substances (TBARS) concentration. The rats mesenteric beds were isolated and cannulated to have their pressure variation assessed after crescent doses of phenylephrine (Phe), acetylcholine (ACh) and sodium nitroprusside (SNP).nnnRESULTSnEEGC acutely reduced MAP the dose of 100u202fmg/kg. In the 4-week assay, EEGC acted as diuretic after acute administration after 1, 2, 3 and 4 weeks of treatment. EEGC also acted as an antihypertensive and it showed significant difference already after 1 week (and after 3 and 4 weeks) compared to control, with its MAP close to pre-surgery values at the end of the experiment. It promoted ACE inhibition, which led to lower aldosterone levels. The lower TBARS and higher nitrite concentration found in the EEGC group suggest antioxidant activity and NO maintenance. Moreover, EEGC counteracted the impairment of vascular reactivity induced by renovascular hypertension. The extract group presented thinner left ventricle wall compared to the control, meaning reduced hypertension-induced cardiac remodeling.nnnCONCLUSIONSnThe G. celosioides diuretic effect is maintained on renovascular hypertensive rats and can reduce the blood pressure after the first week of treatment by inhibiting ACE and these effects are longstanding and strong enough to promote protection against cardiac remodeling. Therefore, it shows potential as an antihypertensive drug.