Ethnopharmacological investigation of the cardiovascular effects of the ethanol-soluble fraction of Aloysia polystachya (Griseb.) Moldenke leaves in spontaneously hypertensive rats

ETHNOPHARMACOLOGICAL RELEVANCE

Aloysia polystachya (Griseb) Moldenke (Verbenaceae), popularly known as "burrito", is a South American species widely prescribed by local Brazilian healers for the treatment of cardiovascular diseases. However, its antihypertensive and cardioprotective effects are still unknown.

AIM

To evaluate the role of the ethanol-soluble fraction of A. polystachya leaves (ESAP) against hypertension in spontaneously hypertensive rats (SHRs), as well as its safety, morphoanatomical and phytochemical aspects.

MATERIALS AND METHODS

First, the leaves and stems of A. polystachya were analyzed by optical and scanning electron microscopy in order to provide anatomical data for quality control. Then, ESAP was obtained and its chemical profile was analyzed by LC-DAD-MS. In addition, the cytotoxic and acute toxicity potential of ESAP were evaluated in six cell lines and in female Wistar rats, respectively. Next, female spontaneously hypertensive rats (SHRs) received ESAP (30, 100, 300 mg/kg), hydrochlorothiazide (25 mg/kg), or vehicle once daily for 28 days. Weekly kidney function was monitored by analyzing urinary parameters. At the end of the 28-day treatment, the electrocardiographic profile, blood pressure, and renal and mesenteric vascular reactivity were evaluated. Relative organ (heart, kidney, and liver) weights and biochemical parameters were also evaluated. Finally, the heart, kidneys, and aorta were collected for determination of the tissue redox state, cardiac morphometry, and histopathological analysis.

RESULTS

The chemical profile of ESAP was composed by organic acids, a nucleoside, methoxylated flavones and glycosylated compounds including phenolic acids, phenylpropanoids, iridoids and monoterpenes. No signs of toxicity were observed in all cell's lines nor in female Wistar rats submitted to this trial. All SHRs from the negative control group presented a reduction in renal function, alterations in the renal and mesenteric vascular reactivity, and electrocardiographic and morphometric changes typical of ventricular hypertrophy. Oral prolonged ESAP-administration in SHRs was able to reverse renal, electrocardiographic and hemodynamic changes induced by hypertension. Moreover, ESAP-treatment was able to modulate the vascular and renal arterial reactivity and tissue redox state. The aforementioned data were accompanied by reduction of cardiac hypertrophy.

CONCLUSION

In this study, we present important anatomical and phytochemical data that contributed to the correct identification and quality control of A. polystachya. In addition, we have shown that ESAP is safe after acute administration and present significant cardioprotective effects (at 30, 100, and 300 mg/kg doses) in SHRs after prolonged treatment.

Ethnopharmacological investigations of the leaves of Cecropia pachystachya Trécul (Urticaceae): A native Brazilian tree species

ETHNOPHARMACOLOGICAL RELEVANCE

Cecropia pachystachya Trécul (Urticaceae) is a medicinal plant popularly known as 'embaúba'. In Brazil, the leaves of this species are used for the treatment of various kidney and cardiovascular diseases. However, there are no detailed studies on the renal and cardiovascular activities of this species. No studies on the anatomy or the quality control of this herbal drug is available thus far.

AIM

This study was aimed to investigate the ethnopharmacological properties of the leaves of C. pachystachya.

MATERIAL AND METHODS

The leaves of C. pachystachya were analyzed by light and scanning electron microscopy for pharmacobotanical and anatomical characterization. The ethanol-soluble fraction of C. pachystachya leaf extract (ESCP) was characterized by high-performance liquid chromatograph equipped with diode array detector and mass spectrometry (HPLC-DAD-MS). The acute oral toxicity of ESCP on female Wistar rats was assessed. The acute and prolonged diuresis and antioxidant effects of ESCP (30, 100, and 300 mg/kg) were evaluated in male Wistar rats. In addition, the hypotensive effects of the ESCP as well as the vasodilatory activity in isolated and perfused mesenteric vascular beds were investigated.

RESULTS

The anatomical markers obtained in this study can help in the identification of C. pachystachya, as well as to distinguish it from the other 'embaúbas'. The metabolites found in the ESCP were phenolic compounds, mainly C- and O-glycosylated flavonoids. The ESCP did not exhibit any toxic effects at a dose of 2000 mg/kg. Significant diuretic activities were observed at the doses of 30, 100, and 300 mg/kg. In addition, a significant modulating activity of the tissue redox state was observed after prolonged treatment. On the other hand, no hypotensive or vasodilator activity was observed.

CONCLUSION

The key findings of the present study can contribute to the taxonomy, species identification and quality control of C. pachystachya. Chemical studies have shown the presence of glycosylated flavonoids, phenylpropanoid derivative and proanthocyanidins. The pharmacological studies showed significant diuretic and antioxidant effects of C. pachystachya leaf extract, indicating a possible validation of its popular medicinal use.

Cuphea calophylla var. mesostemon (Koehne) S.A. Graham: A Whole-Ethnopharmacological Investigation

Several species of Cuphea are used medicinally and are reported to have cardioprotective, diuretic, and antihypertensive properties. In Brazil, Cuphea species are collectively called "sete-sangrias" due to their similar appearances and are also used interchangeably for the same therapeutic purposes. So the aim of the study was to characterize morphoanatomy of leaves and stems, evaluate the safety, and investigate the diuretic, hypotensive, vasodilatory, and antioxidant properties of ethanol-soluble fraction of Cuphea calophylla var. mesostemon (Koehne) S.A. Graham. Initially, the morphoanatomical characterization of the leaves and stems of C. calophylla var. mesostemon was performed. For the pharmacological evaluation, the ethanol-soluble fraction from Cuphea calophylla (ESCC) was obtained and chemically characterized by high-performance liquid chromatography coupled with a diode array detector and tandem mass spectrometry techniques. Then, acute toxicity, diuretic, hypotensive, antioxidant, and vasodilatory effects were evaluated in Wistar rats. The main chemical compounds identified from ESCC were gallic acid derivatives, ellagitannins, and flavonoids. ESCC showed no acute toxic effect. ESCC showed no acute toxic effect and the estimated median lethal dose (LD₅₀) was above 2000 mg/kg. ESCC treatment (30, 100, and 300 mg/kg) did not present any significant acute diuretic or hypotensive effects. However, an important reduction in the elimination of electrolytes was observed after the acute administration, and a significant increase in renal sodium elimination was observed after 7 days of treatment. In the cardiac tissue, the groups treated with ESCC presented significant increase in superoxide dismutase activity.

Co-Loaded Curcumin and Methotrexate Nanocapsules Enhance Cytotoxicity against Non-Small-Cell Lung Cancer Cells

Background: As part of the efforts to find natural alternatives for cancer treatment and to overcome the barriers of cellular resistance to chemotherapeutic agents, polymeric nanocapsules containing curcumin and/or methotrexate were prepared by an interfacial deposition of preformed polymer method. Methods: Physicochemical properties, drug release experiments and in vitro cytotoxicity of these nanocapsules were performed against the Calu-3 lung cancer cell line. Results: The colloidal suspensions of nanocapsules showed suitable size (287 to 325 nm), negative charge (-33 to -41 mV) and high encapsulation efficiency (82.4 to 99.4%). Spherical particles at nanoscale dimensions were observed by scanning electron microscopy. X-ray diffraction analysis indicated that nanocapsules exhibited a non-crystalline pattern with a remarkable decrease of crystalline peaks of the raw materials. Fourier-transform infrared spectra demonstrated no chemical bond between the drug(s) and polymers. Drug release experiments evidenced a controlled release pattern with no burst effect for nanocapsules containing curcumin and/or methotrexate. The nanoformulation containing curcumin and methotrexate (NCUR/MTX-2) statistically decreased the cell viability of Calu-3. The fluorescence and morphological analyses presented a predominance of early apoptosis and late apoptosis as the main death mechanisms for Calu-3. Conclusions: Curcumin and methotrexate co-loaded nanocapsules can be further used as a novel therapeutic strategy for treating non-small-cell lung cancer.

The wound healing effect of aqueous extract from Piper amalago L. in diabetic patient

Diabetes patients present a complex healing process due to several factors directly linked to their pathology. The use of medicinal plants that aid in tissue repair can bring great benefits to such individuals. This case report describes how the topical application of the aqueous extract produced from the leaves of Piper amalago L. was used to aid the healing of a lacerated wound in the left thumb of a patient with type 2 diabetes mellitus. The aqueous extract of the leaves of Piper amalago L. was prepared in boiling water. During the boiling process the dried leaves were submerged in the boiling water and left for five min. The injured thumb was submerged in the solution and the leaves were placed on the injury. The action of the aqueous extract obtained from the leaves of P. amalago was shown to be promising in the healing of a wound in a patient with type 2 diabetes mellitus. The topical application of the aqueous extract produced from the leaves of P. amalago assisted in the healing of a lacerated wound in the left thumb of a patient with type 2 diabetes mellitus over a period of 15 days.

Ethnopharmacological approaches to Talinum paniculatum (Jacq.) Gaertn. - Exploring cardiorenal effects from the Brazilian Cerrado

ETHNOPHARMACOLOGICAL RELEVANCE

Talinum paniculatum (Jacq.) Gaertn. (Talinaceae), popularly known as "major gomes" and "erva gorda", is a non-conventional food plant extensively distributed throughout the Brazilian territory. In Brazilian folk medicine, this species is used as aphrodisiac, to treat gastrointestinal problems, and as a cardioprotective agent. However, there are no reports in the literature proving its cardiovascular effects.

AIM

To perform a whole-ethnopharmacological investigation of the cardiorenal properties of the ethanol soluble fraction from T. paniculatum (ESTP) in Wistar rats.

MATERIAL AND METHODS

First, plant samples were collected, properly identified and a morpho-anatomical characterization was carried out to provide quality control parameters. Then, ESTP was obtained and its chemical profile was determined by LC-DAD-MS. In addition, an acute toxicity assay was conducted in female Wistar rats in order to observe any toxic effects after one single administration. Finally, the diuretic and hypotensive potential of ESTP (30, 100 and 300 mg/kg) were investigated in male rats followed by the evaluation of its possible effects on peripheral vascular resistance.

RESULTS

Chemical compounds identified from ESTP were chlorogenic acids, amino acids, nucleosides, O-glycosylated flavones and organic acids. No signs of toxicity as well as no changes in urine volume or electrolyte elimination were observed after ESTP acute treatment. On the other hand, prolonged treatment with all doses of ESTP significantly increased urine volume and electrolyte excretion (Na⁺, K⁺ and Cl^-) without affecting blood pressure or heart rate. Apparently, these effects are involved with the activation of the small conductance calcium-activated potassium channels contributing to the increase of renal blood flow and glomerular filtration rate.

CONCLUSION

Data presented show important information about the ethnomedicinal properties of T. paniculatum. In addition, the study presents the ESTP as a possible herbal medicine, especially when a sustained diuretic effect is required.

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

ETHNOPHARMACOLOGICAL RELEVANCE

Celosia 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.

AIM

To perform a detailed ethnopharmacological investigation of the ethanol soluble fraction from C. argentea (ESCA) using male and female Wistar rats.

MATERIAL AND METHODS

Firstly, 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 300 mg/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.

RESULTS

The 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 24 h after administration. Intermediary dose (100 mg/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.

CONCLUSION

This 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.

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

ETHNOPHARMACOLOGICAL RELEVANCE

Although Luehea divaricata Mart. (Malvaceae) is popularly used by the population of the Brazilian Pantanal for the treatment of different types of kidney diseases, no study has been carried out to prove this ethnobotanical indication.

AIM

To investigate the possible cardiorenal effects of an herbal preparation obtained from L. divaricata leaves.

MATERIALS AND METHODS

First, to provide quality control standards, a detailed morphological and microchemical characterization of L. divaricata leaves was performed. Then, the purified aqueous extract was obtained from the leaves of this species (ESLD) and a thorough phytochemical characterization was performed. Subsequently, acute oral toxicity test was performed after single administration of different doses (5, 50, 300, 2000mg/kg) in male and female Wistar rats. Finally, the diuretic, hypotensive and antioxidant properties of ESLD (30, 100, 300mg/kg) were evaluated after acute and prolonged treatment and the role of angiotensin converting enzyme, aldosterone, vasopressin, and nitric oxide in these effects was investigated.

RESULTS

Analyses performed by liquid chromatography-mass spectrometry showed that the main secondary metabolites present in ESLD were flavonol O-glycosides and flavone C-glycosides. Acute and prolonged treatment with ESLD was able to expressively increase urinary volume and electrolyte excretion. Mean blood pressure and systolic blood pressure were also significantly reduced after acute treatment. Moreover, treatment with ESLD was able to reduce thiobarbituric acid reactive species and increase serum nitrate levels.

CONCLUSION

The data obtained showed that ESLD has an important diuretic and hypotensive effect, which is probably dependent on the reduction of oxidative stress and increased bioavailability of nitric oxide.

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

ETHNOPHARMACOLOGICAL RELEVANCE

Acanthospermum 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.

AIM

To carry out a detailed ethnopharmacological investigation of the cardio-renal properties of A. hispidum.

MATERIALS AND METHODS

First, 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.

RESULTS

The 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.

CONCLUSION

Data 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.

Atheroprotective effects of Cuphea carthagenensis (Jacq.) J. F. Macbr. in New Zealand rabbits fed with cholesterol-rich diet

ETHNOPHARMACOLOGICAL RELEVANCE

Although Cuphea carthagenensis (Jacq.) J. F. Macbr. is used in Brazilian folk medicine in the treatment of atherosclerosis and circulatory disorders, no study evaluating these effects has been conducted. The aim of this study was to evaluate the possible hypolipemiant and antiatherogenic activity of the ethanol soluble fraction obtained from C. carthagenensis (ES-CC) in an experimental atherosclerosis model using New Zealand (NZ) rabbits undergoing cholesterol-rich diet (CRD).

MATERIAL AND METHODS

Dyslipidemia and atherogenesis were induced by administration of standard commercial diet increased of 1% cholesterol (CRD) for 8 weeks. ES-CC was orally administered at doses of 10, 30 and 100mg/kg, once daily for four weeks, starting from the 4th week of CRD diet. Body weight measurements were weekly carried out from the beginning of experiments for 8 weeks. Serum levels of triglyceride (TG), total cholesterol (TC) and their fractions (LDL-C, VLDL-C and HDL-C) were measured at the beginning of experiments and at weeks four and eight. After euthanasia of rabbits, aorta segments (aortic arc, thoracic, abdominal and iliac segments) were macroscopically and microscopically evaluated and the intima and media layers of the arteries were measured. Additionally, the antioxidant activity of ES-CC and its influence on the functioning of hepatic antioxidant enzymes were also determined.

RESULTS

CRD induced dyslipidemia and major structural changes in the aortic wall. In addition, an increase in lipid peroxidation and a reduction of hepatic glutathione and serum nitrite levels were observed. Treatment with ES-CC was able to prevent the increase in TC, LDL-C, VLDL-C levels and triglycerides and promoted an increase in HDL-C levels in NZ rabbits. These effects were accompanied by a significant reduction in oxidative stress and modulation of the catalase and superoxide dismutase function. Moreover, the intima and media layers of the arterial segments were significantly reduced by ES-CC treatment.

CONCLUSIONS

This study demonstrated that ES-CC reduces serum lipids and hepatic oxidative stress when orally administered to NZ rabbits. In addition, it was able to prevent the development of CRD-induced atherosclerosis.

Análise morfoanatômica comparativa de duas espécies de carqueja: Baccharis microcephala DC. e B. trimera (Less.) DC., Asteraceae

A identificação de espécies de Baccharis que são constituídas de cladódios, ou seja, caules alados, apresenta dificuldades até mesmo para especialistas em taxonomia vegetal. Baccharis microcephala e B. trimera pertencem ao grupo Trimera e são conhecidas vulgarmente como carquejas. Na medicina popular, é comum o uso de espécies aladas para a aplicação terapêutica como diurético, hepatoprotetor e digestivo. Baccharis trimera consta na F. Bras. IV e possui atividades antiinflamatória, analgésica, bacteriostática, bactericida e antidiabética. As espécies B. trimera e B. microcephala são freqüentemente confundidas e utilizadas pela população para as mesmas finalidades terapêuticas. Objetivou-se estudar a morfologia externa e a anatomia dos cladódios dessas espécies, com a finalidade de se obterem dados que auxiliem na diferenciação e conseqüentemente na identificação das mesmas, contribuindo para o controle de qualidade de fitoterápicos, além de auxiliar na caracterização do grupo taxonômico. O material botânico foi submetido às microtécnicas fotônica e eletrônica de varredura usuais. As duas espécies são trialadas, sendo que em B. microcephala as alas são estreitas, praticamente contínuas em toda a extensão caulinar, enquanto que em B. trimera as alas são mais largas e interrompidas. As características morfológicas permitem a diferenciação dessas duas espécies, principalmente os tricomas tectores.