Cardioprotective Effects of Aloysia polystachya Essential Oil on a Rat Model with Multiple Cardiovascular Risk Factors.

Traditional medicine is a frequently utilized method to treat cardiovascular disease and its primary risk factors, including hypertension and dyslipidemia. Aloysia polystachya is a species that is commonly employed to treat various pathological conditions, and it has already been identified as having some cardioprotective effects. This study aimed to investigate the protective effects of the essential oil extracted from the leaves of A. polystachya in a rat model that simulates multiple cardiovascular risk factors. We evaluate the acute toxicity, as well as the cardioprotective effects, by giving different doses of A. polystachya essential oil (1.47 mg/kg, 4.40 mg/kg, and 13.20 mg/kg) over a period of 42 days. The control group was treated with rosuvastatin (5 mg/kg). At the end of the treatments, the renal function, electrocardiography, blood pressure, vascular reactivity, serum biochemical profile, and organ histopathology were evaluated. The main compounds identified in the essential oil of A. polystachya using gas chromatography coupled with mass spectrometry were beta-myrcene (1.08%), limonene (40.13%), and carvone (56.47%). The essential oil of A. polystachya not only lacks acute toxicity but also mitigates the reduction in the excretion of sodium, chloride, and creatinine in urine. Furthermore, it reduces electrocardiographic abnormalities and decreases blood pressure levels. Moreover, this treatment prevents an elevation in markers of inflammation and oxidative stress in the bloodstream. Our findings indicate significant cardioprotective effects of the essential oil of A. polystachya against multiple risk factors for cardiovascular diseases in hypertensive rats.

Chemical Profiles and Cytotoxic Activities of Essential Oils from Six Species of Baccharis Subgenus Coridifoliae (Asteraceae).

Several Baccharis species are popularly known in traditional medicine as "carquejas", "vassouras", "ervas-santas" and "mio-mios", and are used as anti-inflammatories, digestives, and diuretics. This study aimed to investigate the chemical compositions and cytotoxic activities of essential oils (EOs) of six Baccharis species belonging to subgenus Coridifoliae, namely B. albilanosa, B. coridifolia, B. erigeroides, B. napaea, B. ochracea, and B. pluricapitulata. GC/MS analyses of the EOs showed that the oxygenated sesquiterpenes spathulenol (7.32-38.22 %) and caryophyllene oxide (10.83-16.75 %) were the major components for all the species. The EOs of almost all species were cytotoxic against cancer (BT-549, KB, SK-MEL and SK-OV-3) and normal kidney (VERO and LLC-PK1) cell lines, whereas B. erigeroides EO showed cytotoxicity only against LLC-PK1. This article augments the current knowledge about the chemical-biological properties of Baccharis subgenus Coridifoliae and discusses the therapeutic potentials of these economically unexploited plants.

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.

The NO-cGMP-K+ Channel Pathway Participates in Diuretic and Cardioprotective Effects of Blutaparon portulacoides in Spontaneously Hypertensive Rats.

Blutaparon portulacoides is a Brazilian plant species that is widely used in folk medicine. The present study investigated the role of an aqueous extract of B. portulacoides against hypertension in spontaneously hypertensive rats. The aqueous extract of B. portulacoides was obtained from the whole plant. Its chemical profile was analyzed by ultraperformance liquid chromatography-tandem mass spectrometry. The acute toxicity of the aqueous extract of B. portulacoides was evaluated in female Wistar rats. Male 6-month-old spontaneously hypertensive rats then received the aqueous extract of B. portulacoides (30, 100, and 300 mg/kg), hydrochlorothiazide (25 mg/kg), or vehicle once daily for 28 days. On days 1, 14, and 28, the diuretic effects of the aqueous extract of B. portulacoides were evaluated. The role of prostaglandins and the nitric oxide-cyclic guanosine monophosphate-potassium channel pathway in the diuretic activity of the aqueous extract of B. portulacoides was also investigated. At the end of the treatment, hepatic and renal biochemical markers, serum nitrotyrosine, malondialdehyde, nitrite, and aldosterone levels, and angiotensin-converting enzyme activity were measured. The electrocardiographic profile, blood pressure, and renal vascular reactivity were also assessed. The heart, kidneys, and liver were collected to determine relative organ weight, histopathology, and cardiac morphometry. Caffeic acid, ferulic acid, and several flavonoids were identified in the aqueous extract of B. portulacoides. No signs of toxicity were observed. Prolonged treatment with the aqueous extract of B. portulacoides (300 mg/kg) induced significant diuretic activity by activating the nitric oxide-cyclic guanosine monophosphate-potassium channel pathway. These effects reduced blood pressure and oxidative stress and prevented renal vascular dysfunction and left ventricular hypertrophy that was induced by hypertension. Overall, the present data suggest that the aqueous extract of B. portulacoides has important diuretic and cardioprotective effects by activation of the nitric oxide-cyclic guanosine monophosphate-potassium channel pathway.

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.

Repeated dose 90-day oral toxicity study of Vitex megapotamica (Spreng.) Moldenke.

Vitex megapotamica (Spreng.) Moldenke is a plant with medicinal properties popularly used in Brazil to treat diabetes and obesity. Despite the promising use of this plant, are still incipient toxicology studies on prolonged periods of treatment. The aim of this study was to evaluate the repeated dose 90-day oral toxicity study of V. megapotamica methanolic extract (VMME) in male and female Wistar rats. Different groups of rats (n = 8) were treated daily with three different doses of VMME (100, 300, and 900 mg/kg) or vehicle (filtered water). Body weight, water, and feed consumption, and clinical and behavioral changes were monitored daily. At the end of the experimental period, blood samples were obtained for hematological and biochemical analyzes. After euthanasia, the vital organs were removed for the determination of relative weight and for histopathological analysis. No clinical signs of toxicity or mortality were found during the experimental period. Treatment with VMME did not induce any change in body weight gain, eating patterns, and behavior. We found no statistically significant changes in the different hematological and biochemical parameters evaluated. The relative weight of the organs and histopathological analysis did not show any significant change when compared to animals treated with the vehicle. The data obtained in this study allow us to conclude that the VMME obtained from V. megapotamica is safe after a repeated-dose 90-day oral toxicity study in male and female Wistar rats.

Thyroid-disrupting effects of chlorpyrifos in female Wistar rats.

Thousands of chemicals are released into the environment daily, arousing great scientific interest because they can influence the overall function of living organisms. The indiscriminate use of pesticides, especially organophosphate, confers important risks to both public and environmental health. Previous studies showed that chlorpyrifos (CPF) acts as an endocrine disruptor. Nevertheless, CPF is still widely used in many countries. Thus, we evaluated the thyroid-disrupting effects of CPF after short-term low-dose oral exposure in female Wistar rats. A total of 48 female Wistar rats were divided into five experimental groups (n = 8/group) that were treated orally by gavage with vehicle (control) and chlorpyrifos (0.01, 0.1, 1, and 10 mg/kg) for 5 days. Clinical signs of toxicity were observed throughout treatment. On day 6, the animals were weighed. Serum samples were obtained to measure levels of thyroid hormones, alanine aminotransferase, aspartate aminotransferase, bilirubin, glutamyl transpeptidase, and estradiol. The animals were then euthanized by deep anesthesia with isoflurane. The thyroid gland, liver, spleen, and kidneys were collected to determine relative organ weight and perform histopathological analyses. We observed a significant increase in total triiodothyronine (T3) levels in all CPF treatment groups, even at very low doses that corresponded to the Acceptable Daily Intake. Only the highest dose tested significantly increased both total and free T3 levels. In the group that received the highest dose of CPF, thyroid follicles had irregular contours and few or no colloids. The present results indicated that short-term low-dose CPF exposure in female rats induced significant thyroid-disrupting effects.

Hepato- and cardioprotective effects of Baccharis trimera (Less.) DC. against multiple risk factors for chronic noncommunicable diseases.

Cardiovascular diseases are associated with high morbidity and mortality worldwide and have several risk factors, including dyslipidemia, smoking, and hypertension. Studies have evaluated isolated risk factors in experimental models of cardiovascular disease, but few preclinical studies have assessed associations between multiple risk factors. In the present study, hypertensive Wistar rats (Goldblatt 2K1C model) received a 0.5% cholesterol diet and were exposed to tobacco smoke for 8 weeks. During the last 4 weeks, the animals were treated with vehicle, an ethanol-soluble fraction of B. trimera (30, 100, and 300 mg/kg), or simvastatin + enalapril. A group of normotensive, non-dyslipidemic, and non-smoking rats was treated with vehicle. The levels of aspartate aminotransferase, alanine aminotransferase, urea, creatinine, and hepatic and fecal lipids, blood pressure, and mesenteric arterial bed reactivity were evaluated. Cardiac, hepatic, and renal histopathology and tecidual redox state were also investigated. Untreated animals exhibited significant changes in blood pressure, lipid profile, and biomarkers of heart, liver, and kidney damage. Treatment with B. trimera reversed these changes, with effects that were similar to simvastatin + enalapril. These findings suggest that B. trimera may be promising for the treatment of cardiovascular and hepatic disorders, especially disorders that are associated with multiple risk factors.

Safety assessment of MEFAS: an innovative hybrid salt of mefloquine and artesunate for malaria treatment.

Malaria is a global public health problem that causes approximately 445 000 deaths annually worldwide, especially in underdeveloped countries. Because of the high prevalence and mortality of the disease, new and less toxic therapeutic agents need to be developed, such as MEFAS, a low-cost hybrid salt that consists of artesunate and mefloquine. However, the efficacy of MEFAS has been systematically demonstrated, its safety requires further investigation. This study investigated the acute toxicity of MEFAS and its precursors, artesunate, and mefloquine. A total of 42 female Swiss mice were divided into seven groups (n = 6/group) that were treated orally by gavage with vehicle (filtered water, negative control), MEFAS (50, 500, and 1000 mg/kg), and 1:1 concentrations of artesunate + mefloquine (50, 500, and 1000 mg/kg). Clinical signs of toxicity were observed for 14 d after treatment. On day 15, the animals were weighed, deeply anesthetized with isoflurane, and euthanized for subsequent collection of the liver, spleen, and kidneys. The relative organ weights were determined, followed by histopathological analysis. Artesunate + mefloquine produced toxic effects compared with the negative control group, reflected by changes in clinical signs, relative organ weights, and histopathological alterations. In MEFAS-treated animals, no changes were observed compared with the negative control group. These findings demonstrate that MEFAS is safer than artesunate + mefloquine after acute administration in mice.

Ethnomedicinal Plants Used for the Treatment of Cardiovascular Diseases by Healers in the Southwestern State of Paraná, Brazil, and Their Validation Based on Scientific Pharmacological Data.

Cardiovascular diseases are responsible for high morbidity and mortality rates worldwide. Among treatment options, medicinal plants are frequently used, especially in developing countries, such as Brazil. Despite social development that has been observed in the last decades, the use of medicinal plants is still driven by popular knowledge, especially by healers. The present study sought to identify medicinal species that are used for the treatment of cardiovascular diseases by healers in the microregion of Francisco Beltrão, Paraná, Brazil. The snowball technique was used to select informants, and data were collected through interviews. The research was performed in two stages: (1) a structured interview and (2) the collection and botanical identification of the species that were mentioned by the healers. Medicinal plants were classified into the following categories of cardiovascular agents: hypotensive and antihypertensive agents, lipid-lowering agents, diuretic agents, and cardiotonic agents. To analyze the data, the frequency was determined, Spearman correlations were calculated, and the informant consensus factor (ICF) and use value were obtained. Some characteristics, such as female gender and old age, were associated with knowledge about medicinal plants. Overall, 77 different species and 149 medicinal uses were cited by the healers. With regard to categories of use, the highest number of species was found among lipid-lowering plants, and the highest ICF was found for species that are used as cardiotonics. Moreover, a literature review indicated that among the cited species, several still lack studies that have proven their effects on the cardiovascular system. The traditional use of medicinal plants for the treatment of cardiovascular diseases is broad in the study regions. The present results are important for clarifying popular knowledge in this region and providing a framework for selecting species with potential for the development of new pharmacological studies.

Traditional Plants Used by Remaining Healers from the Region of Grande Dourados, Mato Grosso do Sul, Brazil.

Although the traditional use of medicinal plants is a very widespread practice in Brazil, there are still few studies aimed at native prescribers, known as healers. The aim of this work was to catalog the medicinal species prescribed by remaining healers of the Grande Dourados region, Mato Grosso do Sul, Brazil. Semi-structured interviews were conducted with support of a standardized questionnaire for remaining healers selected using the "snowball" technique. The medicinal species selected were collected, identified, and classified according to the British National Formulary. Remaining healers were identified in seven municipalities in the region of Grande Dourados. Family, divine revelation, and participation of the Catholic Church were the most important sources of knowledge. Seventy-one medicinal species, mainly herbaceous belonging to Asteraceae, Lamiaceae, Amaranthaceae, and Verbenaceae families, were the most prescribed. Most species are used in the treatment of digestive and cardiovascular diseases, in addition to immune and respiratory diseases. Healers from the region of Grande Dourados maintain considerable ethno-knowledge about the medicinal properties of different medicinal species. Sharing this information values their culture and preserves the knowledge for future generations.

Molecular docking to Toxoplasma gondii thymidylate synthase-dihydrofolate reductase and efficacy of raltitrexed in infected mice.

Toxoplasmosis is a zoonosis of worldwide distribution. Currently, two drugs, pyrimethamine and sulfadiazine, are used as a reference in the treatment of toxoplasmosis, but the resistance of Toxoplasma gondii appears as a relevant public health problem. In order to identify new drugs to toxoplasmosis treatment, we performed a molecular docking of raltitrexed to T. gondii thymidylate synthase-dihydrofolate reductase (TS-DHFR) and also evaluated its efficacy in infected mice. Initially, raltitrexed was docked on the crystallographic structures of TS-DHFR from T. gondii and Mus musculus. Then, 48 h after infection with the T. gondii RH strain, different groups of mice received an oral dose of raltitrexed (0.15, 0.75, and 1.5 mg kg-1). Two days after treatments, raltitrexed was able to prevent mortality and reduce the number of tachyzoites in the peritoneal fluid and liver imprints from infected mice. The results showed that raltitrexed has important protective activities against the T. gondii RH strain. Molecular docking still suggests that the effects against the parasite may be dependent on the inhibition of T. gondii thymidylate synthase. This study opens new perspectives for the use of raltitrexed in patients infected with T. gondii, especially when conventional treatments do not exhibit the expected efficacy.

Effects of extracts from Echinacea purpurea (L) MOENCH on mice infected with different strains of Toxoplasma gondii.

In recent years, due to the growing concern about recurrent epidemics by Toxoplasma gondii and other pathogens in Brazil, there has been an increase in the use of different preparations obtained from Echinacea purpurea in order to test their effectiveness against these infections. Although studies have suggested the beneficial effects of this species against the influenza virus, no data are available on the use of E. purpurea aqueous extract in T. gondii infections. Thus, the aim of this study was to analyze the effect of its administration in Swiss mice submitted to acute and prolonged infection with different T. gondii strains. This study showed that E. purpurea extract induced a significant reduction in the number of tachyzoites in the peritoneal fluid and liver imprints from mice infected by the RH strain. Moreover, prolonged treatment significantly increased the number of brain cysts of animals infected with ME 49 strain. The results obtained in this study suggest that the crude extract obtained from E. purpurea has important protective activities against infection with different T. gondii strains.

Cytotoxicity, anti-inflammatory effect, and acute oral toxicity of a novel Attalea phalerata kernel oil-loaded nanocapsules.

The kernel oil of the Attalea phalerata Mart. Ex Spreng (Acurí) is traditionally used in several Latin American countries to treat respiratory problems, inflammation, and fever. However, it cannot be found on the literature any attend to use this oil in pharmaceutical formulation. In this paper, it was developed Acurí oil-loaded nanocapsules, and it was evaluated the cytotoxicity against cancer cells, the antinflammatory activity and the oral acute toxicity in rats. Acurí oil contains lauric acid as the predominant saturated fatty acid (433.26 mg/g) and oleic acid as the main unsaturated fatty acid (180.06 mg/g). The Acurí oil-loaded nanocapsules showed a size of 237 nm, a polydispersity index of 0.260, and a high ζ-potential of -78.75 mV. It was obtained an encapsulation efficiency of 88.77%, and the nanocapsules remain stable on the shelf for 180 days. The nanocapsules showed a rapid release profile (98.25% in 40 minutes). Nanocapsules at a dose of 10 mg/kg exhibit an anti-inflammatory effect similar to indomethacin at the same dose. The nanocapsules showed excellent antiproliferative effect and selectivity index against prostate tumor cells (IC50 2.09 µg/mL, SI=119.61) and kidney tumor cells (IC50 3.03 µg/mL, SI=82.50). Both Acurí oil and Acurí oil-loaded nanocapsules are nontoxic at a dose of 2000 mg/kg. Additionally, they reduce serum triglyceride and total cholesterol levels in rat and could find application in nutraceutical formulations. The Acurí oil-loaded nanocapsules emerge as a promising candidate for new antitumor therapies.

Exploring antioxidant and α-glucosidase inhibition in Eugenia L. extracts: a comprehensive phytochemical study.

This study analysed extracts obtained from the leaves of Eugenia uniflora, E. involucrata, and E. myrcianthes to determine their chemical composition, antioxidative properties, and α-glucosidase inhibitory capacity. By using liquid chromatography with a diode array detector, we identified chlorogenic acids, flavonoids, tannins, proanthocyanidins, saponins, and triterpenes in the extracts. The antioxidant activities of the extracts were found to be directly related to their total phenolic, flavonoid content and enzyme inhibition. The E. uniflora aqueous extract showed significant inhibition of α-glucosidase (IC50 0.98 µg mL-1), indicating its potential as a non-competitive inhibitor for managing Diabetes Mellitus. This study contributes to the existing knowledge on the chemical and biological aspects of Eugenia genus.

Ateroprotective effects of Plinia cauliflora in. New Zealand rabbits: beyond the lipid-lowering effect.

Introduction: Plinia cauliflora [Mart.] Kausel (Myrtaceae), popularly known as "jabuticaba," is a fruit species native to Brazil. Despite extensive widespread usage, its antiatherosclerotic properties' impact remains unknown. Thus, the present study aimed to investigate the cardioprotective effects of a preparation obtained from the fruit peels of P. cauliflora (EEPC). Methods: Male New Zealand rabbits received a 1% cholesterol-supplemented diet for 60 days. On the thirtieth day, the animals were divided into five experimental groups and received, once a day, by the oral route, the EEPC (10, 30, and 100 mg/kg), simvastatin (2.5 mg/kg), or vehicle for 30 days. At the end of the experimental period, peripheral blood and arterial branch samples were collected. The levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), malondialdehyde (MDA), nitrotyrosine (NT), nitrite, interleukin 1 beta (IL-1b), interleukin 6 (IL-6), soluble inter-cellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1) levels were measured. Moreover, the catalase and superoxide dismutase levels were measured on the arterial samples. Histopathological analysis and arterial morphometry were also performed. Results and discussion: The oral administration of ESEG significantly lowered the levels of lipids in rabbits that were fed a CRD diet. This treatment also adjusted the protective system against oxidation in the arteries by decreasing the oxidation of lipids and proteins. Additionally, the levels of IL-1b, IL-6, sICAM-1, and sVCAM-1 in the bloodstream decreased significantly, and this was accompanied by a reduction of atherosclerotic lesions in all branches of the arteries. The findings suggest that EEPC may be a possible option for additional management of atherosclerosis.

Acute toxicity and genotoxicity of Schinus molle L. aqueous extract/ethanol-soluble fraction in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Schinus molle L. is a medicinal species belonging to the Anacardiaceae family. It is commonly referred to as "aroeira" and its leaves and roots are utilized for treating different pathological conditions. However, despite its widespread use in traditional medicine, there is a lack of in-depth toxicological studies. AIM: To evaluate the acute toxicity and genotoxicity of S. molle aqueous extract/ethanol-soluble fraction in rats. MATERIAL AND METHODS: First, a purified aqueous extract was obtained from the leaves of S. mole through infusion (referred to as EESM) and its compounds were identified using LC-DAD-MS data. Female rats were then subjected to acute oral toxicity tests using doses of 5, 50, 300, and 2000 mg/kg of ESSM. Studies on genetic material, including the micronucleus test and comet assay, were conducted on male and female Wistar rats using the same doses as in the acute toxicity test. For both assays, ESSM was administered orally. RESULTS: The main metabolites annotated from ESSM were dimeric proanthocyanidins, phenylpropanoids acids, flavan-3-ols, simple organic acids (C6-C1), a flavonol di-O-glycosylated (rutin), and O-glycosylated megastigmane. The ESSM did not exhibit any acute toxic effects, such as changes in biochemical, hematologic, or histopathological analysis. Furthermore, no changes were observed in comet assay or micronucleus tests when rats were given doses of 5, 50, 300, or 2000 mg/kg of ESSM. CONCLUSION: The results showed that the ESSM does not induce acute toxicity or exhibit genotoxicity up to a dose of 2000 mg/kg.

Pharmacological Advances for Treatment in Hypertension.

Hypertension plays a significant role in the development of cardiovascular disease and renal diseases, which can heighten the likelihood of experiencing related conditions like myocardial infarction, stroke, and heart failure [...].

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.

Pulegone Prevents Hypertension through Activation of Muscarinic Receptors and Cyclooxygenase Pathway in L-NAME-Induced Hypertensive Rats.

The current study was designed to determine pulegone's antihypertensive and vasoprotective activity in L-NAME-induced hypertensive rats. Firstly, the hypotensive dose-response relationship of pulegone was evaluated in normotensive anesthetized rats using the invasive method. Secondly, the mechanism involved in hypotensive activity was determined in the presence of pharmacological drugs such as atropine/muscarinic receptor blocker (1 mg/kg), L-NAME/NOS inhibitor (20 mg/kg), and indomethacin/COX inhibitor (5 mg/kg) in anesthetized rats. Furthermore, studies were carried out to assess the preventive effect of pulegone in L-NAME-induced hypertensive rats. Hypertension was induced in rats by administering L-NAME (40 mg/kg) orally for 28 days. Rats were divided into six groups which were treated orally with tween 80 (placebo), captopril (10 mg/kg), and different doses of pulegone (20 mg/kg, 40 mg/kg, and 80 mg/kg). Blood pressure, urine volume, sodium, and body weight were monitored weekly. After 28 days, the effect of pulegone on lipid profile, hepatic markers, antioxidant enzymes, and nitric oxide was estimated from the serum of treated rats. Moreover, plasma mRNA expression of eNOS, ACE, ICAM1, and EDN1 was measured using real-time PCR. Results show that pulegone dose-dependently decreased blood pressure and heart rate in normotensive rats, with the highest effect at 30 mg/kg/i.v. The hypotensive effect of pulegone was reduced in the presence of atropine and indomethacin, whereas L-NAME did not change its hypotensive effect. Concurrent treatment with pulegone for four weeks in L-NAME-treated rats caused a reduction in both systolic blood pressure and heart rate, reversed the reduced levels of serum nitric oxide (NO), and ameliorated lipid profile and oxidative stress markers. Treatment with pulegone also improved the vascular response to acetylcholine. Plasma mRNA expression of eNOS was reduced, whereas ACE, ICAM1, and EDN1 levels were high in the L-NAME group, which was facilitated by pulegone treatment. To conclude, pulegone prevented L-NAME-induced hypertension by demonstrating a hypotensive effect through muscarinic receptors and cyclooxygenase pathway, indicating its use as a potential candidate in managing hypertension.