Role of K+ and Ca2+ Channels in the Vasodilator Effects of Plectranthus barbatus (Brazilian Boldo) in Hypertensive Rats.

Plectranthus barbatus, popularly known as Brazilian boldo, is used in Brazilian folk medicine to treat cardiovascular disorders including hypertension. This study investigated the chemical profile by UFLC-DAD-MS and the relaxant effect by using an isolated organ bath of the hydroethanolic extract of P. barbatus (HEPB) leaves on the aorta of spontaneously hypertensive rats (SHR). A total of nineteen compounds were annotated from HEPB, and the main metabolite classes found were flavonoids, diterpenoids, cinnamic acid derivatives, and organic acids. The HEPB promoted an endothelium-dependent vasodilator effect (~100%; EC50 ~347.10 µg/mL). Incubation of L-NAME (a nonselective nitric oxide synthase inhibitor; EC50 ~417.20 µg/mL), ODQ (a selective inhibitor of the soluble guanylate cyclase enzyme; EC50 ~426.00 µg/mL), propranolol (a nonselective α-adrenergic receptor antagonist; EC50 ~448.90 µg/mL), or indomethacin (a nonselective cyclooxygenase enzyme inhibitor; EC50 ~398.70 µg/mL) could not significantly affect the relaxation evoked by HEPB. However, in the presence of atropine (a nonselective muscarinic receptor antagonist), there was a slight reduction in its vasorelaxant effect (EC50 ~476.40 µg/mL). The addition of tetraethylammonium (a blocker of Ca2+-activated K+ channels; EC50 ~611.60 µg/mL) or 4-aminopyridine (a voltage-dependent K+ channel blocker; EC50 ~380.50 µg/mL) significantly reduced the relaxation effect of the extract without the interference of glibenclamide (an ATP-sensitive K+ channel blocker; EC50 ~344.60 µg/mL) or barium chloride (an influx rectifying K+ channel blocker; EC50 ~360.80 µg/mL). The extract inhibited the contractile response against phenylephrine, CaCl2, KCl, or caffeine, similar to the results obtained with nifedipine (voltage-dependent calcium channel blocker). Together, the HEPB showed a vasorelaxant effect on the thoracic aorta of SHR, exclusively dependent on the endothelium with the participation of muscarinic receptors and K+ and Ca2+ channels.

Natural Products as Modulators of Mitochondrial Dysfunctions Associated with Cardiovascular Diseases: Advances and Opportunities.

The mitochondria have an important role in modulating cell cycle progression, cell survival, and apoptosis. In the adult heart, the cardiac mitochondria have a unique spatial arrangement and occupy nearly one-third the volume of a cardiomyocyte, being highly efficient for converting the products of glucose or fatty acid metabolism into adenosine triphosphate (ATP). In cardiomyocytes, the decline of mitochondrial function reduces ATP generation and increases the production of reactive oxygen species, which generates impaired heart function. This is because mitochondria play a key role in maintaining cytosolic calcium concentration and modulation of muscle contraction, as ATP is required to dissociate actin from myosin. Beyond that, mitochondria have a significant role in cardiomyocyte apoptosis because it is evident that patients who have cardiovascular diseases (CVDs) have increased mitochondrial DNA damage to the heart and aorta. Many studies have shown that natural products have mitochondria-modulating effects in cardiac diseases, determining them as potential candidates for new medicines. This review outlines the leading plant secondary metabolites and natural compounds derived from microorganisms as modulators of mitochondrial dysfunctions associated with CVDs.

Gastroprotective effect of Artemisia absinthium L.: A medicinal plant used in the treatment of digestive disorders.

ETHNOPHARMACOLOGICAL RELEVANCE: Wormwood (Artemisia absinthium L.) is traditionally used for stomach pain and gastric relief. However, its possible gastroprotective effect has not yet been experimentally evaluated. AIM OF THE STUDY: This study evaluated the gastroprotective effect of aqueous extracts obtained through hot and room temperature maceration of A. absinthium aerial parts in rats. MATERIALS AND METHODS: The gastroprotective effect of hot aqueous extract (HAE) and room temperature aqueous extract (RTAE) from A. absinthium aerial parts were evaluated in rats using a model of acute gastric ulcer induced by ethanol p.a. The stomachs were collected to measure the gastric lesion area and histological and biochemical analysis. UHPLC-HRMS/MS analysis was used to determine the chemical profile of the extracts. RESULTS: Eight main peaks in the UHPLC chromatogram were identified in both HAE and RTAE extracts: tuberonic acid glycoside (1), rupicolin (2), 2-hydroxyeupatolide (3), yangabin (4), sesartemin (5), artemetin (6), isoalantodiene (7), and dehydroartemorin (8). For RTAE, a higher diversity of sesquiterpene lactones was observed. The groups treated with RTAE at 3%, 10%, and 30% presented a gastroprotective effect, reducing the lesion area by 64.68%, 53.71%, and 90.04%, respectively, when compared with the vehicle (VEH)-treated group. On the other hand, the groups treated with HAE at 3%, 10%, and 30% presented values of lesion areas higher than those of the VEH group. Changes in the submucosa layer, inflammatory process with edema, cellular infiltration, and mucin depletion were detected in the gastric mucosa exposed to ethanol, which was fully prevented by RTAE treatment. Neither HAE nor RTAE could increase the reduced glutathione levels in the injured gastric tissue, but RTAE (30%) reduced the formation of lipid hydroperoxides. When the rats were pre-treated with NEM (a chelator of non-protein thiols) or L-NAME (non-selective nitric oxide synthase inhibitor), the RTAE lost the ability to protect the gastric mucosa. CONCLUSIONS: This study corroborates the ethnopharmacological use of this specie to treat gastric disorders revealing the gastroprotective effect of the room-temperature aqueous extract of A. absinthium aerial parts. Its mode of action may involve the ability of the infusion to maintain the gastric mucosal barrier integrity.

Endophytic Fungus of Achyrocline satureioides: Molecular Identification, Chemical Characterization, and Cytotoxic Evaluation of its Metabolites in Human Melanoma cell line.

Endophytic fungi are important sources of anticancer compounds. An endophytic fungus was isolated from the medicinal plant Achyrocline satureioides, and molecularly identified as Biscogniauxia sp. (family Xylariaceae) based on partial nucleotide sequences of the internal transcribed spacer genomic region (GenBank Accession No. ON257911). The chemical characterization and cytotoxic properties of secondary metabolites produced by Biscogniauxia sp. were evaluated in a human melanoma cell line (A375). The fungus was grown in potato-dextrose liquid medium for 25 days, and the extracted compounds were subjected to solid-phase fractionation to obtain the purified FDCM fraction, for which the metabolites were elucidated via ultra-performance chromatography coupled to a mass spectrometer. In the present study, 17 secondary metabolites of Biscogniauxia sp., including nine polyketide derivatives, five terpenoids, and three isocoumarins, were putatively identified. This is the first study to report of the ability of Biscogniauxia sp. in the production of isocoumarin orthosporin; the terpenoids nigriterpene A and 10-xylariterpenoid; the polyketide derivatives daldinin C, 7'dechloro-5'-hydroxygriseofulvin, daldinone D, Sch-642305, curtachalasin A, cytochalasin E, epoxycytochalasins Z8, Z8 isomer, and Z17. Furthermore, this study has reported the biosynthesis of Sch-642305 by a Xylariaceae fungus for the first time. FDCM significantly reduced the viability and proliferation of human melanoma cells at half-maximal inhibitory concentrations ​​of 10.34 and 6.89 µg/mL, respectively, and induced late apoptosis/necrosis and cell cycle arrest in G2/M phase after 72 h of treatment. Given its ability to produce unique metabolites with promising cytotoxic effects, Biscogniauxia sp. of A. satureioides may be a reservoir of compounds with important therapeutic applications.

Brazilian Red Propolis Accelerates Gastric Healing and Reduces Gastric Submucosal Layer Inflammation in Ultrasound-Monitored Rats.

Propolis has been used for the treatment of gastric disturbances in folk medicine, nevertheless, the gastric healing effects of Brazilian red propolis have not been unveiled. This study aimed to assess the gastric healing effect of the hydroalcoholic extract of red propolis (HERP) in the acetic acid-induced ulcer model. Rats under acetic acid-induced-ulcer were treated with HERP (100 mg/kg, p.o.) twice a day for seven days. Histological changes, oxidative stress, and inflammatory parameters were analyzed in the gastric tissue. Moreover, the gastric wall thickness was measured by ultrasound. The in vitro cytotoxicity of HERP and cellular migration of fibroblasts were evaluated. The treatment with HERP promoted gastric healing, reducing gastric wall thickness, macroscopic lesion area, and histopathological damages compared to the vehicle. Moreover, HERP reduced oxidative stress and inflammation in the gastric tissue but did not change mucin or collagen levels. HERP did not show signs of toxicity either in vivo or in vitro. HERP displayed a healing effect in vivo by reducing oxidative stress and inflammation. These data contribute to validating the popular use of this product in the treatment of gastric disorders and advance scientific knowledge in the search for new drugs for the management of gastric ulcers.

Dimethyl Cardamonin from Fruits of Campomanesia reitziana D. Legrand Promotes Gastroprotection and Gastric Healing Effects in Rodents.

Campomanesia reitziana D. Legrand (Myrtaceae) displays antiulcer properties when given to rodents. The major active chemical components of C. reitziana are chalcones, including 4',6'-dihydroxy-2'-methoxy-3',5'-dimethylchalcone or dimethyl cardamonin (DMC); therefore, we hypothesized that this compound could have antiulcer effects and the present study aimed to evaluate its gastroprotective and gastric healing properties. DMC was isolated from the fruits of C. reitziana, and its gastroprotective effect was evaluated by ethanol and indomethacin-induced gastric ulcer models in mice (0.1 mg/kg, i.p. and 1 and 3 mg/kg, p.o.). Oxidative stress and inflammatory parameters were analyzed in the gastric tissue. Moreover, its gastric healing effect was evaluated in rats. In addition, the compound's mode of action was evaluated in vivo and in vitro by measuring H+ -K+ -ATPase activity. Finally, the cytotoxic potential of DMC was tested in fibroblasts and human gastric adenocarcinoma cells. The DMC reduced the ethanol-induced gastric ulcer in mice by 77 %, increased the adhered mucus, and reduced lipoperoxides levels. The block of nonprotein sulfhydryls (NP-SH) compounds by pretreatment with N-ethylmaleimide (NEM), the inhibition of nitric oxide synthase with Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME), or the antagonism of α2 receptor using yohimbine reversed the gastroprotective effects of DMC. Furthermore, DMC reduced the acidity of gastric content in pylorus-ligated rats but did not change H+ , K+ -ATPase (isolated from rabbit) activity in vitro. DMC reduced the lesion area in acetic acid-induced ulcers and decreased myeloperoxidase activity. DMC did not change the viability of fibroblast cells (L929) but reduced the viability of human gastric adenocarcinoma cells (AGS). The results confirmed that DMC could significantly enhance the gastric healing process and prevent ulcers due to improving protective factors on the gastric mucosa and reducing gastric acid secretion.

Diuretic and Antiurolithic Effect of Garcinia humilis (Vahl) C.D. Adams Leaves, a Medicinal Plant Native to South American Countries.

This study evaluated the diuretic and antiurolithic effect of methanolic extract (MEGHL), dichloromethane (DCM), and ethyl acetate (EtA) fractions obtained from the leaves of Garcinia humilis, a medicinal plant known as achachairu and native to South American countries such as Bolivia, Peru, and Brazil. For the analysis of diuretic effect, the female rats received the treatment with MEGHL (3, 10, and 30 mg/kg), DCM (1, 3 and 10 mg/kg), EtA (1, 3, and 10 mg/kg), hydrochlorothiazide (HCTZ; 10 mg/kg), or vehicle (VEH) after an overload of saline solution. At the end 8 h of the experiment, the urinary parameters were measured. Additionally, the antiurolithic effect was analyzed, in which sodium oxalate was added in synthetic urine in the presence or absence of MEGHL, DCM, and EtA in different concentrations (0.1, 0.3, and 1 mg/mL). MEGHL, DCM, and EtA were able to promote 8-h diuresis in rats. MEGHL treatment at dose 30 mg/kg was accompanied by increased urinary Na+ , K+ and Cl- excretion. Moreover, the DCM and EtA fractions treatment increased K+ and Cl- excretion in the urine, although it does not cause any change in Na+ elimination. All the preparations were able to exert an antiurolithic effect in vitro, decreasing the number of calcium oxalate crystals of the monohydrate and dihydrate types. Taking together, the results presented herein showed that the preparations of G. humilis leaves are promising strategies to induce diuresis and antiurolithic effects.

Involvement of a neutrophil-mast cell axis in the effects of Piper malacophyllum (C. PESL) C. DC extract and its isolated compounds in a mouse model of dysmenorrhoea.

The effects of Piper malacophyllum (C. Pesl) C. DC extracts and its isolated compounds were analysed in a mouse model of primary dysmenorrhoea (PD). Female Swiss mice (6-8 weeks old) on proestrus were intraperitoneally treated with estradiol benzoate for 3 days, to induce PD. Twenty-four hours later, animals were treated 24 h later with vehicle, plant extract, gibbilimbol B, 4,6-dimethoxy-5-E-phenylbutenolide, mixture of 4,6-dimethoxy-5-E-phenylbutenolide and 4,6-dimethoxy-5-Z-phenylbutenolide, or ibuprofen. One hour later, oxytocin was injected and the numbers of abdominal writhing were counted. Then, mice were euthanized and uteri were collected for morphometrical and histological analyses. The effects of P. malacophyllum in inflammation were investigated in mouse peritoneal neutrophils culture stimulated with LPS or fMLP (chemotaxis and mediator release). Finally, uterus contractile and relaxing responses were assessed. Similar to ibuprofen, P. malacophyllum extract and isolated compounds reduced abdominal writhing in mice with PD. Histology indicated a marked neutrophil and mast cell infiltrate in the uterus of PD animals which was attenuated by the extract. The compounds and the extract reduced neutrophil chemotaxis and inflammatory mediator release by these cells. Reduced TNF levels were also observed in uteri of PD mice treated with P. malacophyllum. The extract did not affect spontaneous uterine contractions nor those induced by carbachol or KCl. However, it caused relaxation of oxytocin-induced uterine contraction, an effect blunted by H1 receptor antagonist. Overall the results indicate that P. malacophyllum may represent interesting natural tools for reliving PD symptoms, reducing the triad of pain, inflammation and spasmodic uterus behaviour.

Exotic Medicinal Plants Used in Brazil with Diuretic Properties: A Review.

Several exotic plants (non-native) are used in Brazilian traditional medicine and are known worldwide for their possible diuretic actions. Among the wide variety of plants, standing out Achillea millefolium L., Camellia sinensis L. Kuntze, Crocus sativus L., Hibiscus sabdariffa Linn., Petroselinum crispum (Mill.) A.W. Hill, Taraxacum officinale (L.) Weber, and Urtica dioica L., whose effects have already been the subject of some scientific study. In addition, we also discussed other exotic species in Brazil used popularly, but that still lack scientific studies, like the species Arctium lappa L., Carica papaya L., Catharanthus roseus (L.) G. Don, Centella asiatica (L.) Urb, Citrus aurantium L., and Persea americana Mill. However, generally, clinical studies on these plants are scarce. In this context, different plant species can be designated for further comprehensive studies, therefore, promoting support for developing an effective medicine to induce diuresis.

Lupeol Stearate Accelerates Healing and Prevents Recurrence of Gastric Ulcer in Rodents.

Objective: The focus of this study was to evaluate the gastric healing effect of lupeol stearate (LS) and its ability to minimize ulcer recurrence in rodents. Methods: To evaluate the gastric healing properties of LS, rats were subjected to 80% acetic acid-induced ulcer model and treated with vehicle, LS (1 mg/kg, p.o.), or omeprazole (20 mg/kg, p.o.), twice daily by seven days. The gastric ulcers were evaluated macroscopically, histologically, and biochemically. To evaluate the effects of LS in gastric ulcer recurrence, mice were ulcerated with 10% acetic acid and treated with vehicle, LS (1 mg/kg, p.o.), or ranitidine (100 mg/kg, p.o.), twice a day for ten days. Then, ulcer recurrence in these animals was induced by IL-1ß at five days after the treatment period. Results: The oral treatment with LS accelerated gastric healing by 63% in rats compared to the vehicle group, evidenced by histological improvement and increased gastric mucin levels. Moreover, the gastric healing effects of LS in rats were accompanied by an elevation in glutathione S-transferase activity and a reduction in myeloperoxidase activity. Furthermore, the LS treatment reduced the recurred lesions in mice. Conclusions: The oral treatment of LS accelerates gastric healing in rats by favoring mucus production and reducing neutrophil migration, and it also can reduce ulcer recurrence. These data highlighted this compound as promising for developing new pharmacological strategies for the management of gastric ulcer.

Boldine, an Alkaloid from Peumus boldus Molina, Induces Endothelium-Dependent Vasodilation in the Perfused Rat Kidney: Involvement of Nitric Oxide and Small-Conductance Ca2+-Activated K+ Channel.

Boldine, 2,9-dihydroxy-1,10-dimethoxyaporphine, is the main alkaloid found in the leaves and bark of Peumus boldus Molina. In recent years, boldine has demonstrated several pharmacological properties that benefit endothelial function, blood pressure control, and reduce damage in kidney diseases. However, the renal vasodilator effects and mechanisms remain unknown. Herein, perfused rat kidneys were used to study the ability of boldine to induce vasodilation of renal arteries. For that, left kidney preparations with and without functional endothelium were contracted with phenylephrine and received 10-300 nmol boldine injections. The preparations were then perfused for 15 min with phenylephrine plus L-NAME, indomethacin, KCl, tetraethylammonium, glibenclamide, apamin, charybdotoxin, or iberiotoxin. In 30, 100, and 300 nmol doses, boldine induced a dose-and endothelium-dependent relaxing effect on the renal vascular bed. No vasodilator effects were observed in preparations lacking functional endothelium. While the inhibition of the cyclooxygenase enzyme through the addition of indomethacin did not cause any change in the vasodilating action of boldine, the nonselective nitric oxide synthase inhibitor L-NAME fully precluded the vasodilatory action of boldine at all doses tested. The perfusion with KCl or tetraethylammonium (nonselective K+ channels blocker) also abolished the vasodilatory effect of boldine, indicating the participation of K+ channels in the renal action of boldine. The perfusion with glibenclamide (selective ATP-sensitive K+ channels blocker), iberiotoxin (selective high-conductance Ca2+-activated K+ channel blocker), and charybdotoxin (selective high- and intermediate-conductance Ca2+-activated K+ channel blocker) did not modify the vasodilatory action of boldine. On the other hand, the perfusion with apamin (selective small-conductance Ca2+-activated K+ channel blocker) completely prevented the vasodilatory action of boldine at all doses tested. Together, the present study showed the renal vasodilatory properties of boldine, an effect dependent on the generation of nitric oxide and the opening of a small-conductance Ca2+-activated K+ channel.

Sambucus nigra: A traditional medicine effective in reducing inflammation in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Sambucus nigra L. is a plant of European origin and popularly known as elder, elderberry, black elder, European elder, European elderberry, and European black elderberry, being described in pharmacopoeia of several countries. Its flowers and berries have been used in folk medicine to treat feverish conditions, coughing, nasal congestion, and influenza besides its popular use as anti-inflammatory, analgesic, and diuretic agent. AIM OF THE STUDY: The aim of this investigation was to elucidate the anti-inflammatory and the relaxant effect of the lyophilized aqueous extract obtained from S. nigra's flowers on in vivo and in vitro inflammation assays and on the isolated rat vascular and airway smooth muscle tissue. MATERIAL AND METHODS: The anti-inflammatory activity of the extract was investigated using carrageenan-induced inflammation model in the subcutaneous tissue of male Swiss mice orally treated with S. nigra extract (30, 100, 300 or 600 mg/kg). Leukocyte influx and the secretion of chemical mediators were quantified in the inflamed exudate. Additionally, histological analysis of the pouches was performed. N-Formyl-methionine-leucine-phenylalanine-induced chemotaxis, lipopolysaccharide-induced TNF, IL-6, IL-1ß, IL-10 and NO production, and adhesion molecule expression (CD62L, CD49d and CD18, flow cytometry) were analyzed in vitro using oyster glycogen-recruited peritoneal neutrophils or macrophages (RAW 264.7) stimulated with LPS and treated with the extract (1, 10 or 100 µg/mL). The resolution of inflammation was accessed by efferocytosis assay, and the antinociceptive activity was investigated using carrageenan-induced mechanical hypersensitivity. Finally, the effect of the extract was evaluated in isolated rat aorta and trachea rings. RESULTS: The oral treatment with S. nigra promoted reduction in the neutrophil migration as well as the decrease of TNF, IL-1ß and IL-6 levels in the inflamed exudate. In vitro treatment with S. nigra decreased NO2-, TNF, IL-1ß and IL-6 and promoted increase of IL-10 in LPS-stimulated neutrophils. Similarly, the extract reduced the NO2-, TNF and IL-6 in LPS-stimulated macrophages. Rutin, the major constituent of S. nigra extract reduced NO2-, TNF, IL-1ß, and IL-6 and promoted the increase of IL-10 in LPS-stimulated neutrophils supernatant. The extract also shed CD62L and CD18 expressions. The extract was able to increase the efferocytosis of apoptotic neutrophils by increasing the IL-10 and decreasing the TNF levels. Additionally, the extract reduced the hypersensitivity induced by carrageenan and promoted a relaxant effect in isolated vascular and non-vascular rat tissue. CONCLUSIONS: S. nigra flowers extract presents anti-inflammatory effect by modulating macrophage and neutrophil functions including the production of inflammatory mediators and cell migration, by promoting efferocytosis and consequently the resolution of acute inflammation, besides exerting antinociceptive effects, scientifically proving its popular use as medicinal plant. Allied to the relaxant effect in both vascular and non-vascular smooth muscle tissue, S. nigra extract represents an important tool for the management of acute inflammation.

Herbal Medicines in the Treatment of Dyspepsia: An Overview.

This review focuses on the efficacy of herbal medicines for managing dyspepsia in humans and animals. Searches were conducted on the PubMed, Science Direct, and Medline databases, for publications in the last 3 years. In each database, the search terms used consisted of the 2 key terms describing the disorder and subtypes plus each of the terms relating to the therapy. The key terms used were "natural product" and "medicinal plant" in a cross-over with "dyspepsia" and "functional dyspepsia" (i.e., gastroprotection, Helicobacter pylori infection, prokinetic). We included all human and animal studies on the effects of herbal medicines reporting the key outcome of dyspepsia symptoms. Preclinical studies using critically validated models showed that most medicinal plants with gastroprotective action had antioxidant, anti-inflammatory, anti-apoptotic, and antisecretory effects. Moreover, several species displayed anti Helicobacter pylori and prokinetic efficacy. The data availability of controlled clinical studies is currently minimal. The use of different methodologies and the minimal number of patients raise doubts about the effects of these preparations. Only adequate clinical trials with scientifically validated methods can determine whether different herbal medicines can be used as viable alternatives to the conventional pharmacological treatments used to control dyspepsia symptoms.

Ethyl Acetate Fraction from Leandra dasytricha (A. Gray) Cong. Leaves Promotes Vasodilatation and Reduces Blood Pressure in Normotensive and Hypertensive Rats.

Leandra dasytricha (A. Gray) Cong. is widely distributed in the south of Brazil and is commonly used for cardiovascular and kidney ailments. For this study, we used male Wistar normotensive rats (NTRs) and spontaneously hypertensive rats (SHRs) to verify the effects of the ethyl acetate fraction (EAF) obtained from L. dasytricha leaves on isolated aorta relaxation and in the arterial blood pressure. The EAF was analyzed by LC-DAD-MS, and several components were annotated, including hydrolysable tannins, triterpenes, and O- and C-glycosylated dihydrochalcones, such as the most intense ion peak relative to C-hexosyl phloretin (nothofagin; compound number 13). The EAF caused a concentration and endothelium-dependent relaxation of the aorta in both NTRs and SHRs. This effect was abolished in the endothelium-denuded aorta. L-NAME, a nonselective nitric oxide synthase inhibitor, and ODQ, a soluble guanylate cyclase inhibitor, entirely blocked the EAF-induced relaxation. The presence of a muscarinic receptor antagonist or a cyclooxygenase inhibitor did not alter the EAF's effectiveness in relaxing the aorta. The preincubation with tetraethylammonium, a Ca2+-activated K+ channel blocker, and with 4-aminopyridine, a voltage-dependent K+ channel blocker, significantly interfered with the EAF's relaxation. However, the incubation with glibenclamide, an ATP-sensitive K+ channel blocker, and barium chloride, an inward-rectifier K+ channel blocker, did not interfere with the EAF-induced relaxation. The EAF treatment also caused a dose-dependent decrease in the mean arterial pressure, systolic arterial pressure, and diastolic arterial pressure of both NTRs and SHRs, without significantly interfering with heart rate values. In conclusion, this study demonstrated the EAF-induced vasorelaxant and hypotensive actions, primarily dependent on the endothelium function and mainly with the participation of the nitric oxide and Ca2+-activated and voltage-dependent K+ channels.

Therapeutic Feasibility of the Natural Products in the Heart Complaints: An Overview.

Heart pain is the most frequent complaint leading patients to seek medical help. Functional heart symptoms, especially chest pain, are prevalent and, according to the International Classification of Diseases (ICD-10), are described as "somatoform autonomous functional disorders of the cardiovascular system." The problem lies in the fact that pain does not always have a somatic background, that is, it may be related to crucial underlying heart disease. The population does not know how to differentiate somatic pain from significant ischemic symptoms, and based on the patient's complaints, traditional medicine ends up treating other underlying cardiac diseases. Many unsuccessful unconventional therapies have been proposed in recent years, including herbal medicines that seek to disrupt the disease's pathogenesis. The present review summarizes research carried out in the last 5 years on natural products' heart complaints, including myocardial ischemia, arrhythmia, and heart failure. Several herbal medicines may be used as a replacement or complementary treatment strategy. A total of 17 medicinal plants have shown promising results in preclinical studies. However, human clinical trials are scarce; only two have been presented. Generally, the data are bland, and many issues have been raised about herbal therapies' safety, efficacy, and mode of action. Besides, relevant clinical trials, future perspectives, and possible clinical applications are discussed.

Tagetes erecta L. flowers, a medicinal plant traditionally used to promote diuresis, induced diuretic and natriuretic effects in normotensive and hypertensive rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Tagetes erecta L., known as marigold, belongs to the Asteraceae family and is mainly found in South America. Despite reports that T. erecta flowers are used in folk medicine to treat cardiovascular and renal diseases, there is no study regarding its diuretic effect. AIM: This study aimed to evaluate the chemical composition and the diuretic efficacy of the hydroethanolic extract from T. erecta (HETE) in normotensive (NTR) and hypertensive (SHR) rats. MATERIAL AND METHODS: The HETE was analyzed by liquid chromatography coupled to diode array detector and mass spectrometry (LC-DAD-MS). Female and male NTR and SHR received the treatment with vehicle, HETE (0.01 mg/kg, 0.1 mg/kg, and 1 mg/kg) or hydrochlorothiazide (HCTZ; 5 mg/kg) orally. The urinary parameters were measured at the end of the 8-h experiment. RESULTS: From HETE, saccharides and triterpenes were the main annotated compounds, such as erythrodiol and ß-amyrin. The urine volume was significantly increased in the groups treated with HETE, in both male and female NTR and SHR rats, compared to the respective vehicle-treated groups. Regarding electrolytes elimination, the treatment with HETE did not reveal significant changes in the urine levels of K+ or Cl-, but it showed a natriuretic and Ca2+-sparing effects. The HETE beneficial result in reducing Ca2+ excretion was confirmed through the protective effect found in front of the urinary calcium oxalate precipitation and crystallization. The combination with HCTZ, a classic diuretic and saluretic medicine, significantly enhanced HETE-induced diuresis, natriuresis, and the Ca2+-sparing effect. On the other hand, the K+-sparing action was improved in the combination of HETE with amiloride, a standard K+-sparing diuretic. In contrast, the combination of HETE with atropine (a non-selective muscarinic receptor antagonist) and indomethacin (an inhibitor of the cyclooxygenase enzyme), promoted an important reduction in urinary volume, but interestingly the natriuretic effect was maintained. CONCLUSION: This study contributed to the preclinical validation of the diuretic efficacy of T. erecta, highlighting this species as promising for the development of new pharmacological strategies for the management of kidney disorders.

Prolonged Diuretic and Renoprotective Effects of a Xanthone Obtained from Garcinia achachairu Rusby in Normotensive and Hypertensive Rats.

The previous study showed that 1,5,8-trihydroxy-4',5'-dimethyl-2H-pyrano(2,3 : 3,2)-4-(3-methylbut-2-enyl) xanthone (TDP) obtained from Garcinia achachairu Rusby (Clusiaceae) branches induces acute diuresis in normotensive (NTR) and spontaneously hypertensive rats (SHR) after 8 h of the experiment. In complementarity, the present study evaluated the prolonged diuretic and renoprotective effects of TDP in both NTR and SHR. The animals received, once a day, oral treatment with TDP (0.1 mg/kg), hydrochlorothiazide (10 mg/kg), or vehicle (VEH; 10 mL/kg). At the end of 7 days, the urine, blood, and kidney samples were collected for biochemical and histological analyzes. The urinary volume of both NTR and SHR after 7 days of treatment with the TDP was significantly increased, associated with augmented urinary electrolyte excretion levels. The treatments did not modify the urinary pH values nor the parameters analyzed in plasma (Na+, K+, Cl-, and Ca2+). Concerning the renal analyzes, when compared with the VEH-treated NTR group, while the activity of the enzymes catalase (CAT) and N-acetyl-ß-D-glucosaminidase (NAG), as well as nitrite levels, were increased, the generation of lipid hydroperoxides and the activity of the enzyme myeloperoxidase (MPO) were unaltered. On the other hand, the activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) and the levels of reduced glutathione (GSH) in kidney homogenates of the SHR group were decreased. However, TDP augmented the levels of GSH and GST activities and reduced the levels of nitrite and the activities of CAT and MPO, when compared with VEH-treated only SHR. Besides, the treatment with TDP alleviated the morphological changes of the renal corpuscle region of SHR. Together, these results revealed the prolonged diuretic effect of TDP and their renal protective effect by improving the antioxidative capacity.

Phytochemistry and Pharmacology of the Genus Equisetum (Equisetaceae): A Narrative Review of the Species with Therapeutic Potential for Kidney Diseases.

The Equisetum genus, Equisetaceae family, is widely distributed worldwide and may be the oldest nonextinct genus on Earth. There are about 30 known species, which are very often used in traditional medicine with diverse applications. This review aimed to compile scientific reports about Equisetum species with relevant pharmacological properties and/or therapeutic potential for kidney diseases. Our bibliographic survey demonstrates that the most widespread traditional use of Equisetum is as a diuretic, followed by the treatment of genitourinary diseases (kidney diseases, urethritis, kidney stones, and others), inflammation, wound healing, rheumatic diseases, prostatitis, and hypertension. The most popular species from the Equisetum genus with medicinal use is E. arvense L., whose diuretic effect was confirmed in animal models and clinical trials. The species E. bogotense Kunth also demonstrated the beneficial effect of inducing diuresis in both experimental and clinical assays. Several other species have also been studied regarding their therapeutic potential, showing different biological actions. Regarding the chemical composition, it contains many active constituents, such as alkaloids, flavonoids, phenol, phytosterols, saponins, sterols, silicic acid, tannin, triterpenoids, and volatile oils. However, despite the widespread traditional use, many species need to be explored in detail for scientific validation of popular use. Indeed, the species of the Equisetum genus have great potential in the management of kidney disorders.

Involvement of Muscarinic Receptors in Hypotensive and Diuretic Effects of Aqueous Soluble Fraction from Asphodelus tenuifolius Cav.

Background. Asphodelus tenuifolius Cav. (Asphodelaceae) is widely used in Pakistan traditional medicine as a hypotensive and diuretic agent. Despite the cardioprotective effects described for A. tenuifolius, the mechanisms involved in its probable hypotensive and diuretic effects have never been evaluated. Firstly, different extracts from A. tenuifolius seeds were obtained, and their antioxidant profiles and chemical constituents by LC-DAD-were determined, including molecular networking by the GNPS platform. Then, to evaluate changes in blood pressure, different groups of anesthetized normotensive rats were intravenously treated with the crude extract (AT-Cr, 1-50 mg/kg), aqueous (AS-AT, 1-25 mg/kg), n-butanol (BS-AT, 1-50 mg/kg), and dichloromethane fraction (DS-AT, 1-80 mg/kg). The diuretic effects of AT-Cr, AS-AT, BS-AT, and DS-AT at 100, 200, and 300 mg/kg, p.o. doses, were also evaluated in comparison with hydrochlorothiazide (HCTZ, 10 mg/kg, p.o). The urinary volume, sodium, potassium, and pH were estimated in the sample collected for 6 h from saline-loaded rats. Using pharmacological antagonists or inhibitors, we determine the involvement of acetylcholine, prostaglandins, and nitric oxide in A. tenuifolius-induced hypotensive and diuresis action. In addition, the activities of angiotensin-converting enzyme, erythrocyte carbonic anhydrase, and renal Na+/K+/ATPase were evaluated in vitro. Acute treatment with crude extract and fractions of A. tenuifolius exhibited significant hypotensive and diuretic potential in normotensive rats. However, AS-AT produced the most potent and significant dose-dependent hypotension and diuretic effects in normotensive rats. Previous treatment with atropine significantly reduced the hypotensive and diuretic action of AS-AT, but pretreatment with indomethacin or L-NAME did not affect these effects. Moreover, the 7-day treatment with AS-AT did not reduce activities of serum angiotensin-converting enzyme, erythrocyte carbonic anhydrase, and renal Na+/K+/ATPase. AS-AT showed four major compound node clusters, which included sugars, alkaloids, nucleoside, amino acid, and glycosylated flavonoids. This research supports and extends the traditional use of A. tenuifolius as a hypotensive and diuretic agent. The results showed that AS-AT from A. tenuifolius could present compounds responsible for hypotensive and diuretic activities through the activation of muscarinic receptors.

Gastric healing effect of p-coumaric acid isolated from Baccharis dracunculifolia DC on animal model.

The p-coumaric acid is a phenolic compound present in large quantities in the extract of Baccharis dracunculifolia DC, a Brazilian medicinal plant used to treat gastric ulcer. Given the necessity for finding new chemical components capable of accelerating gastric healing, in this study, the effects of the p-coumaric acid were evaluated in the acetic acid-induced ulcer model in rats, where histological, inflammatory, and oxidative parameters were analyzed. The healing property was also evaluated in the scratch assay on fibroblast cells (L929) and the cytotoxicity of p-coumaric acid was assessed in both L929 and human gastric adenocarcinoma (AGS) cells by MTT assay. The treatment with p-coumaric acid (10 mg/kg, p.o.) for 7 days, twice a day, decreased by 44.6% the acetic acid-induced gastric ulcer compared with the vehicle-treated group. The vehicle control-treated group showed a larger extension of the ulcer base and an extensive damage into the mucosa and submucosa layers, which were mitigated by the treatment with p-coumaric acid. This beneficial effect was also associated with increased levels of mucin and reduced glutathione, decreased amount of lipid hydroperoxides, and increased superoxide dismutase and catalase activities without interfering with the activity of myeloperoxidase in the gastric tissue. The compound promoted the restructuring of the cell monolayer in the scratch test and did not show toxicity in the L929 cell line, while reduced the viability of the AGS, a lineage of human gastric adenocarcinoma. Thus, p-coumaric acid may be considered a natural source for the treatment of gastric ulcers, by reinforcing protective factors of gastric mucosa and by accelerating gastric healing.