Mechanisms of the antihypertensive effects of Nigella sativa oil in L-NAME-induced hypertensive rats

Current insights and future perspectives of flavonoids: A promising antihypertensive approach

Hypertension, or high blood pressure (BP), is a complex disease influenced by various risk factors. It is characterized by persistent elevation of BP levels, typically exceeding 140/90 mmHg. Endothelial dysfunction and reduced nitric oxide (NO) bioavailability play crucial roles in hypertension development. L-NG-nitro arginine methyl ester (L-NAME), an analog of L-arginine, inhibits endothelial NO synthase (eNOS) enzymes, leading to decreased NO production and increased BP. Animal models exposed to L-NAME manifest hypertension, making it a useful design for studying the hypertension condition. Natural products have gained interest as alternative approaches for managing hypertension. Flavonoids, abundant in fruits, vegetables, and other plant sources, have potential cardiovascular benefits, including antihypertensive effects. Flavonoids have been extensively studied in cell cultures, animal models, and, to lesser extent, in human trials to evaluate their effectiveness against L-NAME-induced hypertension. This comprehensive review summarizes the antihypertensive activity of specific flavonoids, including quercetin, luteolin, rutin, troxerutin, apigenin, and chrysin, in L-NAME-induced hypertension models. Flavonoids possess antioxidant properties that mitigate oxidative stress, a major contributor to endothelial dysfunction and hypertension. They enhance endothelial function by promoting NO bioavailability, vasodilation, and the preservation of vascular homeostasis. Flavonoids also modulate vasoactive factors involved in BP regulation, such as angiotensin-converting enzyme (ACE) and endothelin-1. Moreover, they exhibit anti-inflammatory effects, attenuating inflammation-mediated hypertension. This review provides compelling evidence for the antihypertensive potential of flavonoids against L-NAME-induced hypertension. Their multifaceted mechanisms of action suggest their ability to target multiple pathways involved in hypertension development. Nonetheless, the reviewed studies contribute to the evidence supporting the useful of flavonoids for hypertension prevention and treatment. In conclusion, flavonoids represent a promising class of natural compounds for combating hypertension. This comprehensive review serves as a valuable resource summarizing the current knowledge on the antihypertensive effects of specific flavonoids, facilitating further investigation and guiding the development of novel therapeutic strategies for hypertension management.

Designing novel industrial and functional foods using the bioactive compounds from Nigella sativa L. (black cumin): Biochemical and biological prospects toward health implications

Nigella sativa is one of the nutraceuticals that has gained popularity and studied extensively in recent decades as it is considered a safe medicinal plant for use as a dietary supplement. N. sativa contains a wide variety of bioactive substances, which include polyphenols, volatile oils (thymoquinone and p-cymene), proteins, and peptides. The biological attributes of N. sativa include antioxidant, antimicrobial, antifungal, anti-inflammatory, anticancer, antidiabetic, antihypertensive, hypolipidemic, and antioxidant activities, which have potential applications for the prevention of a variety of chronic diseases. In the food industry, N. sativa improves the sensory qualities, shelf life, strength, and freshness of foods, such as bread, pizza, biscuits, cookies, and cakes. This review discusses the industrial use of N. sativa, which includes processing technologies to enhance its health-promoting properties as well as the isolation of nutraceutical components.

Comprehensive and updated review on anti-oxidant effects of Nigella sativa and its constituent, thymoquinone, in various disorders

Several pharmacological effects were described for Nigella sativa (N. sativa) seed and it has been used traditionally to treat various diseases. In this review article, the updated and comprehensive anti-oxidant effects of N. sativa and its main constituent, thymoquinone (TQ), on various disorders are described. The relevant articles were retrieved through PubMed, Science Direct, and Scopus up to December 31, 2023. Various extracts and essential oils of N. sativa showed anti-oxidant effects on cardiovascular, endocrine, gastrointestinal and liver, neurologic, respiratory, and urogenital diseases by decreasing and increasing various oxidant and anti-oxidant marketers, respectively. The main constituent of the plant, TQ, also showed similar anti-oxidant effects as the plant itself. The anti-oxidant effects of different extracts and essential oils of N. sativa were demonstrated in various studies which were perhaps due to the main constituent of the plant, TQ. The findings of this review article suggest the possible therapeutic effect of N. sativa and TQ in oxidative stress disorders.

Thymoquinone: A comprehensive review of its potential role as a monotherapy for metabolic syndrome

Metabolic syndrome (MetS) is a widespread global epidemic that affects individuals across all age groups and presents a significant public health challenge. Comprising various cardio-metabolic risk factors, MetS contributes to morbidity and, when inadequately addressed, can lead to mortality. Current therapeutic approaches involve lifestyle changes and the prolonged use of pharmacological agents targeting the individual components of MetS, posing challenges related to cost, compliance with medications, and cumulative side effects. To overcome the challenges associated with these conventional treatments, herbal medicines and phytochemicals have been explored and proven to be holistic complements/alternatives in the management of MetS. Thymoquinone (TQ), a prominent bicyclic aromatic compound derived from Nigella sativa emerges as a promising candidate that has demonstrated beneficial effects in the treatment of the different components of MetS, with a good safety profile. For methodology, literature searches were conducted using PubMed and Google Scholar for relevant studies until December 2023. Using Boolean Operators, TQ and the individual components of MetS were queried against the databases. The retrieved articles were screened for eligibility. As a result, we provide a comprehensive overview of the anti-obesity, anti-dyslipidaemic, anti-hypertensive, and anti-diabetic effects of TQ including some underlying mechanisms of action such as modulating the expression of several metabolic target genes to promote metabolic health. The review advocates for a paradigm shift in MetS management, it contributes valuable insights into the multifaceted aspects of the application of TQ, fostering an understanding of its role in mitigating the global burden of MetS.

Bioactive molecules from terrestrial and seafood resources in hypertension treatment: focus on molecular mechanisms and targeted therapies

Hypertension (HTN), a complex cardiovascular disease (CVD), significantly impacts global health, prompting a growing interest in complementary and alternative therapeutic approaches. This review article seeks to provide an up-to-date and thorough summary of modern therapeutic techniques for treating HTN, with an emphasis on the molecular mechanisms of action found in substances found in plants, herbs, and seafood. Bioactive molecules have been a significant source of novel therapeutics and are crucial in developing and testing new HTN remedies. Recent advances in science have made it possible to understand the complex molecular mechanisms underlying blood pressure (BP)-regulating effects of these natural substances better. Polyphenols, flavonoids, alkaloids, and peptides are examples of bioactive compounds that have demonstrated promise in influencing several pathways involved in regulating vascular tone, reducing oxidative stress (OS), reducing inflammation, and improving endothelial function. The article explains the vasodilatory, diuretic, and renin-angiotensin-aldosterone system (RAAS) modifying properties of vital plants such as garlic and olive leaf. Phytochemicals from plants are the primary in traditional drug development as models for novel antihypertensive drugs, providing diverse strategies to combat HTN due to their biological actions. The review also discusses the functions of calcium channel blockers originating from natural sources, angiotensin-converting enzyme (ACE) inhibitors, and nitric oxide (NO) donors. Including seafood components in this study demonstrates the increased interest in using bioactive chemicals originating from marine sources to treat HTN. Omega-3 fatty acids, peptides, and minerals obtained from seafood sources have anti-inflammatory, vasodilatory, and antioxidant properties that improve vascular health and control BP. Overall, we discussed the multiple functions of bioactive molecules and seafood components in the treatment of HTN.

Antihypertensive effects of Nigella sativa supplementation: An updated systematic review and meta-analysis of randomized controlled trials

Clinical studies have suggested that Nigella Sativa (N. sativa) supplementation may effectively reduce blood pressure, but the findings are controversial. Therefore, this study aimed to examine the effects of N. sativa on blood pressure in adults. PubMed, Cochrane Library, Web of Science, Scopus, Embase databases, and Google Scholar were searched till August 2022. To analyze weighted mean differences (WMDs), a random-effects model was utilized. Nonlinear dose-response analysis and a meta-regression were conducted. N. sativa supplementation was effective in reducing both systolic (WMD: -3.06 mmHg; 95% CI: -3.89 to -2.22, p < 0.001; I2  = 84.7%, p < 0.001) and diastolic blood pressure (WMD = -2.69 mmHg; 95% CI: -3.72, -1.66, p < 0.001; I2  = 97.3%, p < 0.001). The current meta-analysis suggests that N. sativa supplementation can improve blood pressure and claims that N. sativa could be used as an effective approach to blood pressure management.

Antioxidant Thymoquinone and Its Potential in the Treatment of Neurological Diseases

Oxidative stress is one of the main pathogenic factors of neuron damage in neurodegenerative processes; this makes it an important therapeutic target to which the action of neuroprotectors should be directed. One of these drugs is thymoquinone. According to modern data, this substance has a wide range of pharmacological activity, including neuroprotective, which was demonstrated in experimental modeling of various neurodegenerative diseases and pathological conditions of the brain. The neuroprotective effect of thymoquinone is largely due to its antioxidant ability. Currently available data show that thymoquinone is an effective means to reduce the negative consequences of acute and chronic forms of cerebral pathology, leading to the normalization of the content of antioxidant enzymes and preventing an increase in the level of lipid peroxidation products. Antioxidant properties make this substance a promising basis for the development of prototypes of therapeutic agents aimed at the treatment of a number of degenerative diseases of the central nervous system.

The effect of nigella supplementation on blood pressure: A systematic review and dose-response meta-analysis

This study was performed to assess the effect of nigella supplementation on blood pressure levels among the adult population. A comprehensive search was carried out through PubMed, Scopus, Web of Science, and Cochrane Library by using relevant keywords to find out the randomized clinical trials evaluating the effect of nigella administration on systolic blood pressure (SBP) and diastolic blood pressure (DBP). A random-effect model was applied to achieve the overall effect size. Subgroup analysis and meta-regression were used to explore the source of heterogeneity and the effects of the possible moderators. Of the twenty-two trials that were eligible for the present study, seventeen studies consisting of 1048 participants were included in the meta-analysis. The results indicated that nigella administration could significantly reduce both SBP (-4.58 mmHg; 95%CI: -6.22, -2.94) and DBP (-3.08 mmHg; 95%CI: -4.62, -1.55). Subgroup analysis did not show any superiority between subgroups of variables. Dose-response analysis detected a nonlinear association between dose and duration of administration and change in blood pressure outcomes, highlighting that maximum SBP and DBP reduction was experienced at 2000 mg/day and 8 weeks of nigella administration, respectively. The present study suggests that nigella supplementation can be beneficial for managing blood pressure.

Effect of Nigella Sativa Oil on Oxidative Stress, Inflammatory, and Glycemic Control Indices in Diabetic Hemodialysis Patients: A Randomized Double-Blind, Controlled Trial

Background and Aims

Diabetes is a leading cause of renal failure. High levels of oxidative stress and inflammation in patients with renal diabetes lead to various disorders and mortality. This study was performed to determine the effect of Nigella sativa (NS) supplementation on superoxide dismutase (SOD), malondialdehyde (MDA), total antioxidant capacity (TAC), high-sensitivity C-reactive protein (hs-CRP), glycosylated hemoglobin (HbA1c), fasting blood sugar (FBS), and insulin (INS) in patients with diabetes mellitus undergoing hemodialysis (HD).

Methods

In this randomized, double-blind, placebo-controlled clinical trial, a total of 46 diabetic HD patients were randomly divided into NS (n = 23) and placebo (n = 23) groups. NS group received 2 g/day of NS oil, and the placebo group received paraffin oil for 12 weeks. Serum levels of SOD, MDA, TAC, hs-CRP, HbA1C, FBS, and INS were measured before and after the study.

Results

Compared to baseline values, SOD, TAC, and INS levels increased, whereas MDA, hs-CRP, HbA1c, and FBS significantly decreased. After adjusting for covariates using the ANCOVA test, changes in the concentrations of SOD (p = .040), MDA (p = .025), TAC (p=<.001), hs-CRP (p = .017), HbA1c (p = .014), and FBS (p = .027) were statistically significant compared to the placebo group. Intergroup changes in INS were not significant. Additionally, there were no notable side effects during the research.

Conclusions

This study found that NS supplementation significantly enhanced the levels of SOD, MDA, TAC, hs-CRP, HbA1c, and FBS in diabetic HD patients.

A Comparative Study of the Antihypertensive and Cardioprotective Potentials of Hot and Cold Aqueous Extracts of Hibiscus sabdariffa L. in Relation to Their Metabolic Profiles

Ethnopharmacological relevance: Since ancient times, Hibiscus sabdariffa L. calyces have been used as a folk remedy for the treatment of hypertension. However, it is questionable as to whether there is a difference in the antihypertensive activity of the hot or cold aqueous extracts.

Aim of the study: We designed this study to specify the best method for water extraction of the antihypertensive metabolites of H. sabdariffa and to confirm their in vivo antihypertensive capabilities.

Materials and methods: The powdered dried calyces of H. sabdariffa were independently extracted with cold and hot water. A comparative study was performed between the cold and hot aqueous extracts of H. sabdariffa based on evaluation of the in vitro renin and angiotensin-converting enzyme (ACE) inhibition activities. Additionally, both extracts were subjected to an in vivo study for the evaluation of their antihypertensive activities in L-N^w-Nitro arginine methyl ester (L-NAME)–induced hypertensive rats. Further, a metabolomics study was also performed for both extracts to identify their chemical constituents.

Results: The cold and hot extracts significantly reduced the angiotensin II, ACE, and aldosterone levels in the plasma. Furthermore, in the myocardium and aorta, decreased iNOS (inducible nitric oxide synthase) levels and elevated eNOS (endothelial nitric oxide synthase), as well as the rise in plasma NO levels, were reported with both extracts, but better results were displayed with the hot extract, leading to a potential antihypertensive effect. Additionally, the cold and hot Hibiscus extracts induced a cardioprotective effect through reducing necrosis, inflammation, and vacuolization that results from the induction of hypertension, an effect that was more prominent with the hot extract. Moreover, a comprehensive metabolomics approach using ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC–MS/MS) was able to trace the metabolites in each extraction.

Conclusion: The extracts showed different anthocyanin and phenolic compounds, but the hot extract showed higher contents of specific phenolics to which the superior antihypertensive and cardioprotective activities could be related.

Medicinal Plants in the Treatment of Hypertension: A Review

Traditional medicine is a comprehensive term for ancient, culture-bound health care practices that existed before the use of science in health matters and has been used for centuries. Medicinal plants are used to treat patients with cardiovascular diseases, which may occur due to ailments of the heart and blood vessels and comprise heart attacks, cerebrovascular diseases, hypertension, and heart failure. Hypertension causes difficulty in the functioning of the heart and is involved in atherosclerosis, raising the risk of heart attack and stroke. Many drugs are available for managing these diseases, though common antihypertensive drugs are generally accompanied by many side effects. Medicinal herbs have several active substances with pharmacological and prophylactic properties that can be used in the treatment of hypertension. This review presents an overview of some medicinal plants that have been shown to have hypotensive or antihypertensive properties.

Effects of garden cress, fenugreek and black seed on the pharmacodynamics of metoprolol: an herb-drug interaction study in rats with hypertension

CONTEXT

Garden cress (GC), fenugreek (FG), and black seed (BS) are traditional herbal medicine for managing hypertension.

OBJECTIVE

The effects of the three herbs on the pharmacodynamics of metoprolol tartrate (MT) in hypertensive rats were investigated.

MATERIALS AND METHODS

Wistar rats were divided in five groups (n = 6). Group I served as normal control group and Group II (hypertensive control group) had rats treated orally with N-nitro L-arginine methyl ester (L-NAME, 40 mg/kg/day) only. Groups III, IV, and V rats were orally treated with L-NAME (40 mg/kg/day) + GC (300 mg/kg, once daily), L-NAME (40 mg/kg/day) + FG (300 mg/kg, once daily) and L-NAME (40 mg/kg/day) + BS (300 mg/kg, once daily), respectively, for 2 weeks, and on the 14th day, blood pressure and heart rate were recorded using a tail-cuff blood pressure-measuring system. On the 16th day, a single dose of MT (10 mg/kg) was orally administered, and the rats' blood pressure and heart rate were recorded.

RESULTS

GC, FG, and BS decreased systolic blood pressure (SBP) by 8.7%, 8.5%, and 8.7%, respectively, in hypertensive rats. A greater decrease in SBP by 14.5%, 14.8%, and 16.1% was observed when hypertensive rats were treated with L-NAME + GC + MT, L-NAME + FG + MT, and L-NAME + BS + MT, respectively. Similarly, hypertensive rats treated with the combination of herbs and MT had significantly lower diastolic blood pressure (DBP) than those treated with herbs alone and those treated with L-NAME alone.

CONCLUSIONS

The combination of investigated herbs and MT had a beneficial effect on hypertension. However, the concurrent administration of drugs, particularly those predominantly cleared through CYP450 2D6-catalyzed metabolism, with the three investigated herbs should be considered with caution.

The Role of Bioactive Compounds of Nigella sativa in Rheumatoid Arthritis Therapy-Current Reports

Black cumin (Nigella sativa, NS) is included in the Ranunculaceae family and is classified as a medicinal plant due to very high levels of various bioactive compounds. They determine its therapeutic effects, including anti-inflammatory, anti-allergic, anti-cancer, hypoglycemic, antioxidant, hypotensive, hypolipidemic, and immunomodulating properties. The results of scientific studies indicate a supporting role of black cumin in the treatment of autoimmune diseases, including rheumatoid arthritis, due to the health-promoting properties of its bioactive ingredients. The aim of the current article is to analyze the results of scientific publications on the role of bioactive ingredients contained in black cumin in the treatment of rheumatoid arthritis.

The potential role of thymoquinone in preventing the cardiovascular complications of COVID-19

A new virus strain detected in late 2019 and not previously described in humans is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes corona virus disease (COVID-19). While potential therapeutic approaches for COVID-19 are being investigated, significant initiatives are being made to create protective drugs and study various antiviral agents to cure the infection. However, an effective treatment strategy against COVID-19 is worrisome inadequate. The objective of the present manuscript is to discuss the potential role of thymoquinone (TQ) in preventing the cardiovascular complications of COVID-19, focusing on viral inhibition, antioxidant potential, vascular effect, and cardiac protection. The multifunctional properties of TQ could potentially synergize with the activity of current therapeutic interventions and offer a basis for managing COVID-19 disease more effectively. Even though the experimental evidence is positive, a translational application of TQ in COVID-19 is timely warranted.

Effect of Nigella sativa oil extract on cardiometabolic risk factors in type 2 diabetes: A randomized, double-blind, placebo-controlled clinical trial

The objective of this study was to determine the effects of Nigella sativa oil extract on cardiometabolic risk factors in people with type 2 diabetes (T2D). A randomized, controlled, clinical trial was conducted on 43 patients with T2D (23 women and 20 men; aged 53.5 ± 7.4 years). The intervention group (N = 23) received two 500-mg per day soft gel capsules containing Nigella sativa oil extract and the control group (N = 20) received two identical placebo soft gel capsules containing sunflower oil per day for the same period, 8 weeks. Pre- and post-intervention cardiometabolic risk factors were measured. Compared with the placebo, the N. sativa oil significantly decreased FBS (p = .03(, HbA1c (p = .001), total cholesterol (p = .04), TG (p = .003), LDL-c (p = .001), BMI (p < .001), waist circumference (p < .001), SBP (p = .001), and DBP (p = .002). HOMA-IR (p = .51) and HDL-c (p = .91) did not change significantly following Nigella sativa supplementation. Nigella sativa oil exerted beneficial effects on glycemic control, serum lipid profile, blood pressure, and body weight among people with T2D. Further long-term trials in the future may help confirm the current therapeutic benefits of Nigella sativa in T2D.

Effects of Nigella sativa oil supplementation on selected metabolic parameters and anthropometric indices in patients with coronary artery disease: A randomized, double-blind, placebo-controlled clinical trial

Various metabolic parameters are risk factors related to the amplified risk of atherosclerotic cardiovascular disease. A wide variety of data exist on Nigella sativa (NS) and metabolic parameters. The current study is designed to examine NS supplementation on lipid profile, blood pressure, glycemic control, anthropometric indices, and insulin resistance in individuals with coronary artery disease (CAD). In a randomized, double-blind, placebo-controlled clinical trial, 60 patients with CAD received either 2 g of NS oil or sunflower oil as a placebo for 8 weeks. Biochemical and anthropometric measurements were assessed. NS significantly reduced weight (-1.82 Kg; 95% C, [2.72, 4.13]), body mass index (-0.67 kg/m² ; 95% C, [0.33, 1.01]), waist circumference (-2.15 cm; 95% C, [1.06, 3.23]), hip circumference (-1.26 cm; 95% C, [0.61, 1.910]), waist-to-hip ratio (0.008; 95%C, [0.001, 0.01]), systolic (-9.52 mmHg; 95% C, [7.14, 11.9]), diastolic blood pressure (-8.26 mmHg; 95% C, [4.89, 11.62]), and fasting blood glucose (FBS) (-4.32 mg/dl; 95% C, [-0.51, 9.15]) as compared with the placebo group. The results indicate a potential beneficiary effect of NS on the metabolic parameters in CAD patients including improvements in anthropometric indices, blood pressure, and FBS.

Plants Used as Antihypertensive

Hypertension is a critical health problem and worse other cardiovascular diseases. It is mainly of two types: Primary or essential hypertension and Secondary hypertension. Hypertension is the primary possibility feature for coronary heart disease, stroke and renal vascular disease. Herbal medicines have been used for millions of years for the management and treatment of hypertension with minimum side effects. Over aim to write this review is to collect information on the anti-hypertensive effects of natural herbs in animal studies and human involvement as well as to recapitulate the underlying mechanisms, from the bottom of cell culture and ex-vivo tissue data. According to WHO, natural herbs/shrubs are widely used in increasing order to treat almost all the ailments of the human body. Plants are the regular industrial units for the invention of chemical constituents, they used as immunity booster to enhance the natural capacity of the body to fight against different health problems as well as herbal medicines and food products also. Eighty percent population of the world (around 5.6 billion people) consume medicines from natural plants for major health concerns. This review provides a bird's eye analysis primarily on the traditional utilization, phytochemical constituents and pharmacological values of medicinal herbs used to normalize hypertension i.e. Hibiscus sabdariffa, Allium sativum, Andrographis paniculata, Apium graveolens, Bidenspilosa, Camellia sinensis, Coptis chinensis, Coriandrum sativum, Crataegus spp., Crocus sativus, Cymbopogon citrates, Nigella sativa, Panax ginseng,Salviaemiltiorrhizae, Zingiber officinale, Tribulus terrestris, Rauwolfiaserpentina, Terminalia arjuna etc.

Effects of Nigella sativa oil and thymoquinone against bisphenol A-induced metabolic disorder in rats

The underlying mechanisms of bisphenol A (BPA)-induced metabolic disorder and the protective impact of Nigella sativa oil (NSO) and thymoquinone (TQ) against BPA-induced metabolic disorder were investigated. Rats were treated as follows: Control, BPA (10 mg/kg), TQ (2 mg/kg), NSO (84 μL/kg), BPA + TQ (0.5, 1, 2 mg/kg), and BPA + NSO (21, 42, 84 μL/kg). BPA was administered by gavage, while, TQ and NSO were injected intraperitoneally (daily, 54 days). The weight, blood pressure, serum parameters [glucose, lipid profile, hepatic enzymes, insulin, interlukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), leptin, adiponectin], malondialdehyde (MDA), glutathione (GSH) and insulin signaling pathways [insulin receptor substrate (p-IRS,IRS); kinase (p-Akt,Akt); glycogen synthase kinase (p-GS3K,GS3K)] were measured. BPA increased the blood pressure, MDA, lipid profile, hepatic enzymes, insulin, IL-6, TNF-α, and leptin, and decreased the GSH and phosphorylated forms of IRS, Akt, GS3K but did not alter weight, glucose, IRS, AKT, and GS3K in the liver. Administration of NSO or TQ with BPA reduced the blood pressure, liver level of MDA, lipid profile, hepatic enzymes, insulin, IL-6, TNF-α, leptin, and increased the liver level of GSH and p-IRS, p-AKT, p-GS3K. TQ and NSO are thought to be effective in controlling metabolic disorders induced by BPA.

Natural Product Heme Oxygenase Inducers as Treatment for Nonalcoholic Fatty Liver Disease

Heme oxygenase (HO) is a critical component of the defense mechanism to a wide variety of cellular stressors. HO induction affords cellular protection through the breakdown of toxic heme into metabolites, helping preserve cellular integrity. Nonalcoholic fatty liver disease (NAFLD) is a pathological condition by which the liver accumulates fat. The incidence of NAFLD has reached all-time high levels driven primarily by the obesity epidemic. NALFD can progress to nonalcoholic steatohepatitis (NASH), advancing further to liver cirrhosis or cancer. NAFLD is also a contributing factor to cardiovascular and metabolic diseases. There are currently no drugs to specifically treat NAFLD, with most treatments focused on lifestyle modifications. One emerging area for NAFLD treatment is the use of dietary supplements such as curcumin, pomegranate seed oil, milk thistle oil, cold-pressed Nigella Satvia oil, and resveratrol, among others. Recent studies have demonstrated that several of these natural dietary supplements attenuate hepatic lipid accumulation and fibrosis in NAFLD animal models. The beneficial actions of several of these compounds are associated with the induction of heme oxygenase-1 (HO-1). Thus, targeting HO-1 through dietary-supplements may be a useful therapeutic for NAFLD either alone or with lifestyle modifications.

Local Usage of Nigella sativa Oil as an Innovative Method to Attenuate Primary Dysmenorrhea: A Randomized Double-blind Clinical Trial

Objectives

We sought to determine the effect of topical application of Nigella sativa (black seed) oil, on the primary dysmenorrhea intensity.

Methods

We conducted a randomized, double-blind clinical trial on 124 female students, 18–22 years old, living in the dormitories of Sabzevar Universities. After a primary assessment, participants were randomly divided into two groups. The first group rubbed two drops of N. sativa oil, and the second group rubbed liquid olive oil, as the placebo. Massage was performed on the fontanel lobe 3, at night, three days before menstruation, for eight consecutive days (about five days after menses). This procedure was repeated for three menstrual cycles. After three cycles, pain severity was measured by the visual analog scale. Data analysis was carried out using the Mann-Whitney U test and analysis of covariance (ANCOVA).

Results

This study was conducted on 124 female students. The mean age of students, mean age of first menarche, body mass index, and pain severity were not significantly different in the two groups (p > 0.050). No adverse effects were observed during the study. The results of ANCOVA showed that pain intensity in N. sativa oil group was significantly decreased compared to that of the placebo group (0.6 score; p < 0.050).

Conclusions

N. sativa could be a promising, safe, and easily available analgesic supplement in women suffering from primary dysmenorrhea.

Nigella sativa (black seed) safety: an overview

Nigella sativa (commonly known as black seed or black cumin), from the family Ranunculaceae, is a plant that grows in countries bordering the Mediterranean Sea. This narrative review discusses the toxicological profile reported by short- to long-term studies that examined different extracts and oils of N. sativa seeds. Scientific databases including Web of Science, PubMed, Scopus, and Google Scholar were searched using appropriate keywords. LD50 for administered N. sativa seed fixed oil varied from 28.8 mL/kg to 3,371 mg/kg in mice, while 21 g/kg of aqueous, methanol, and chloroform extracts of N. sativa did not lead to any mortality. Subacute toxicity evaluations indicated that aqueous, methanol, and chloroform extracts of N. sativa at doses as high as 6 g/kg do not produce toxicity. Investigation of chronic toxicity found that 2 mL/kg of N. sativa fixed oil is slightly toxic. Cytotoxicity studies indicated that N. sativa chloroform and petroleum ether extracts are more cytotoxic than its other extracts. Although studies that assessed N. sativa toxicity generally introduced it as a safe medicinal herb, to draw a more definitive conclusion on its safety, more detailed studies must be conducted.

Alaofi A, Awan ZA, Alqarni HM, Alhakamy NA. Optimization of Thymoquinone-Loaded Coconut Oil Nanostructured Lipid Carriers for the Management of Ethanol-Induced Ulcer

In the global incidence of peptic ulcer, with the associated rates of hospitalizations and mortality are increasing, in the United States, peptic ulcer disease affects approximately 4.6 million people annually, with an estimated 10% of the US population having evidence of a duodenal ulcer. The present research aims to find a novel treatment for ethanol induced ulcer by loading thymoquinone (TQ) on a nanostructured lipid carrier (NLC), using Compritol® 888 and coconut oil. The TQ-loaded coconut oil NLC was formulated using melt emulsification combined with a sonication method using Poloxamer 188 as a surfactant. Finally, the optimization of the formulations was performed on a three-factor, three-level Box-Behnken statistical design, with 85.63% entrapment efficiency of TQ in the optimized formulation. A biphasic release pattern of the formulation was recorded in an in vitro drug release study, where the initial burst release of the drug was observed in the first 2 h, followed by a gradual release. Later, the TQ-loaded coconut oil NLC was found to protect the gastric mucous membrane more effectively (78.95% in.; p < 0.01) in an alcohol-induced ulcer model, whereas the TQ suspension showed 30.87% inhibition (p < 0.05) of the ulcerative index, when compared with the ulcer control group. The histopathological evaluations of the stomach in ulcer-induced animals demonstrated protection potential of TQ-loaded coconut oil NLC against an alcohol-induced gastric ulcer. In a nutshell, the entrapment of TQ within the NLC was found to deliver the entrapped drug more effectively when administered through an oral route to possess a gastroprotective effect.

Effect of Nigella sativa and Fenugreek on the Pharmacokinetics and Pharmacodynamics of Amlodipine in Hypertensive Rats

BACKGROUND

The present article is related to in-vitro and in-vivo herb-drug interaction studies.

OBJECTIVES

This study aimed to investigate the effect of Nigella sativa and fenugreek on the pharmacodynamics and pharmacokinetics of amlodipine.

METHOD

Hypertensive rats of group-I were treated with amlodipine and rats of group-II and III were treated with N. sativa, and N. sativa + amlodipine and fenugreek, and fenugreek + amlodipine, respectively. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean blood pressure (MBP) of group-I, II and III rats were measured by the "tail-cuff system".

RESULTS

N. sativa, as well as fenugreek, reduced the SBP, DBP and MBP. Simultaneously, administration of fenugreek + amlodipine or N. sativa + amlodipine showed better control of BP. Individually, fenugreek, as well as N. sativa, showed a surprising reduction in the heart rate. There was no remarkable effect of any of these two herbs on Cmax, AUC0-t, Kel, and terminal elimination half-life of amlodipine, but fenugreek altered the Tmax of amlodipine significantly, from 2 ± 1.2h in control to 7.2 ± 1.7h in fenugreek treated group, probably by delaying the absorption.

CONCLUSION

Results of pharmacodynamics and pharmacokinetics studies suggested that simultaneous administration of fenugreek or N. sativa with amlodipine improved the pharmacological response of amlodipine in hypertensive rats, though there was no remarkable change in pharmacokinetic parameters (Cmax, Kel, elimination t1/2, and AUC0-t).

Potential pharmacodynamic and pharmacokinetic interactions of Nigella Sativa and Trigonella Foenum-graecum with losartan in L-NAME induced hypertensive rats

The objective of this investigation was to study whether Nigella Sativa and Trigonella Foenum-graecum, could modulate the losartan pharmacodynamic (PD) and pharmacokinetic (PK) in experimental L-NAME induced hypertensive rats. For in vivo study, the systolic blood pressure (SBP) of rats was measured by the “tail-cuff system” after the treatment of rats with herb alone and herb + losartan in hypertensive rats. The SBP of rats treated with L-NAME + losartan also recorded. For the PK study, blood samples were obtained for up to 12 h to determine the concentrations of the drug, and various PK parameters were calculated. The data displayed that the SBP was significantly (p < 0.05) decreased in the rats when administered with L-NAME + N. Sativa or L-NAME + T. Foenum-graecum in contrast to the rats administered with L-NAME alone. A more prominent decline (p < 0.05) in SBP was detected in rats administered with L-NAME + N. Sativa + losartan and L-NAME + T. Foenum-graecum + losartan. In a PK study, higher losartan C_max and AUC_0-t were noted in rats treated with N. Sativa + losartan and T. Foenum-graecum + losartan, although the difference was not significant in contrast to the control group. This study proposed that the interaction between N. Sativa & losartan and T. Foenum-graecum & losartan could take place on concurrent administration; consequently, the dose of losartan may need to be accustomed when they are utilized simultaneously.

An Overview of the Potential Use of Ethno-Medicinal Plants Targeting the Renin-Angiotensin System in the Treatment of Hypertension

The development of risk factors associated with cardiovascular disorders present a major public health challenge in both developed countries and countries with emerging economies. Hypertension and associated complications including stroke and myocardial infarction have reached pandemic levels. Current management strategies of hypertension predominantly include the utilization of pharmaceutical drugs which are often associated with undesirable side effects. Moreover, the drugs are often too expensive for populations from resource-limited Southern African rural, and some urban, communities. As a result, most patients rely on ethno-medicinal plants for the treatment of a variety of diseases including cardiovascular and metabolic disorders. The effectiveness of these plants in managing several cardiovascular diseases has been attributed to the presence of bioactive phytochemical constituents. In this review, the treatment options that target the renin-angiotensin system (RAS) in the management of hypertension were summarized, with special emphasis on ethno-medicinal plants and their influence on the ACE1 RAS pathway. The dearth of knowledge regarding the effect of ethno-medicinal plants on the ACE2 pathway was also highlighted.

Sex differences in cardio-metabolic and cognitive parameters in rats with high-fat diet-induced metabolic dysfunction

IMPACT STATEMENT

Excessive dietary fat intake plays important roles in the process of metabolic dysfunction and increases susceptibilities to chronic diseases such as hypertension. Few previous studies, however, have accurately reflected real-world medical conditions. In addition, studies performed to date have not examined detailed sex-differences in cardio-metabolic and cognitive parameters, precluding the development of sex-tailored interventions for patients with metabolic dysfunction who are susceptible to hypertension and cognitive impairment. In this study, using rats with HFD-induced metabolic dysfunction that made them susceptible to hypertension and cognitive impairment, we demonstrate that male rats show greater impairment of acetylcholine-induced vasorelaxation of the carotid artery and systolic blood pressure compared to female rats. These findings may provide a basis for the early detection of carotid artery dysfunction and systolic blood pressure increase, especially in males.

Thymoquinone as a Potential Neuroprotector in Acute and Chronic Forms of Cerebral Pathology

Thymoquinone is one of the main active components of the essential oil from black cumin (Nigella sativa) seeds. Thymoquinone exhibits a wide range of pharmacological activities, including neuroprotective action demonstrated in the models of brain ischemia/reperfusion, Alzheimer's and Parkinson's diseases, and traumatic brain injury. The neuroprotective effect of thymoquinone is mediated via inhibition of lipid peroxidation, downregulation of proinflammatory cytokines, maintenance of mitochondrial membrane potential, and prevention of apoptosis through inhibition of caspases-3, -8, and -9. Thymoquinone-based mitochondria-targeted antioxidants are accumulated in the mitochondria and exhibit neuroprotective properties in nanomolar concentrations. Thymoquinone reduces the negative effects of acute and chronic forms of brain pathologies. The mechanisms of the pharmacological action of thymoquinone and its chemical derivatives require more comprehensive studying. In this paper, we formulated the prospects of application of thymoquinone and thymoquinone-based drugs in the therapy of neurodegenerative diseases.

Preconditioning with PDE1 Inhibitors and Moderate-Intensity Training Positively Affect Systemic Redox State of Rats

Taken into consideration that oxidative stress response after preconditioning with phosphodiesterase inhibitors (PDEIs) and moderate physical activity has still not been clarified, the aim of this study was to assess the effects of PDEIs alone or in combination with physical activity, on systemic redox status. The study was carried out on 96 male Wistar albino rats classified into two groups. The first group included animals exposed only to pharmacological preconditioning (PreC) maneuver (sedentary control (CTRL, 1 ml/day saline, n = 12), nicardipine (6 mg/kg/day of NIC, n = 12), vinpocetine (10 mg/kg/day of VIN, n = 12), and nimodipine (NIM 10 mg/kg/day of, n = 12). The second included animals exposed to preconditioning with moderate-intensity training (MIT) on treadmill for 8 weeks. After 5 weeks from the start of training, the animals were divided into four subgroups depending on the medication to be used for pharmacological PreC: moderate-intensity training (MIT+ 1 ml/day saline, n = 12), nicardipine (MIT+ 6 mg/kg/day of NIC, n = 12), vinpocetine (MIT+ 10 mg/kg/day of VIN, n = 12), and nimodipine (MIT+ 10 mg/kg/day of NIM, n = 12). After three weeks of pharmacological preconditioning, the animals were sacrificed. The following oxidative stress parameters were measured spectrophotometrically: nitrites (NO₂⁻), superoxide anion radical (O₂⁻), hydrogen peroxide (H₂O₂), index of lipid peroxidation (TBARS), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH). Our results showed that PDE1 and MIT preconditioning decreased the release of prooxidants and improved the activity of antioxidant enzymes thus preventing systemic oxidative stress.

Effects of hydrogen sulphide on oxidative stress, inflammatory cytokines, and vascular remodelling in l-NAME-induced hypertension

This study was designed to evaluate the protective effects of hydrogen sulphide (H₂ S) against NG-Nitro l-Arginine Methyl Ester (l-NAME)-induced hypertension and its possible effects on the inflammatory process, oxidative stress, and vascular remodelling in rats. Forty male Wistar Albino rats were assigned to four equal groups: the control group, the H₂ S control group, the hypertensive group, and the treated group, which received concomitant treatment with sodium hydrosulphide (NaHS) and l-NAME. Systolic blood pressure (SBP) was measured weekly. Serum levels of nitric oxide (NO), total peroxide, and total antioxidant capacity (TAC) were measured and the oxidative stress index (OSI) was calculated. Aortic weight and length were measured and the aortic weight/length ratio determined. Aortic fold expression of interferon-γ (IFN-γ) and vascular cell adhesion molecule-1 (VCAM-1) mRNA was measured using qPCR. Aortic media thickness and elastin content were measured morphometrically. l-NAME administration increased SBP, serum levels of total peroxide and OSI, but reduced serum levels of NO and TAC. Aortic fold expression of IFN-γ and VCAM-1 mRNA, aortic weight, aortic weight/length ratio, aortic media thickness, and elastin area percentage were increased in the hypertensive group. Concurrent administration of l-NAME and H₂ S attenuated these changes. Thus, H₂ S could attenuate the increase in ABP through restoration of the NO level, reduction in the oxidative state, and attenuation of the inflammatory process, thereby reduced vascular remodelling.

Pharmacokinetics of thymoquinone in layer chickens following oral and intravenous administration

Thymoquinone (TQ) is the major constituent of Nigella sativa and known to possess a variety of pharmacological effects. This study was designed to evaluate the pharmacokinetic profile of TQ following oral (PO) and intravenous (IV) administration in layer chickens. The layer chickens were equally divided into two groups (six chickens in each group, total 12 chickens), and TQ was administered via PO and IV routes. For PO route, the dose was 20 mg/kg b.w. and for IV route, 5 mg/kg b.w. was administered, respectively. A sensitive and accurate High-Performance Liquid Chromatography (HPLC) technique was validated for the quantification of TQ from plasma. The limit of detection (LOD) and limit of quantification (LOQ) were 0.02 µg/ml and 0.05 µg/ml, respectively with >80% recovery. Maximum plasma concentration (C_max ) following PO and IV administration was 8.805 and 4.497 µg/ml, respectively, while time to reach at maximum concentration (T_max ) was 1 and 0.1 hr, respectively. The elimination half-lives were recorded as 1.02 and 0.978 hr, whereas the mean residence times were 1.79 and 1.036 hr following both PO and IV administration, respectively. The 85% PO bioavailability was indicative that TQ could be used for various therapeutic purposes in layer chickens.

The standardized extract of Nigella sativa and its major ingredient, thymoquinone, ameliorates angiotensin II-induced hypertension in rats

Background This study investigated the effect of hydroalcoholic extract of Nigella sativa (N. sativa) and its active component, thymoquinone (TQ) on hypertension induced by angiotensin II (AngII), the main product of renin-angiotensin system (RAS). Methods Seven animal groups (n=7 for each group) were used as follows: (1) control, (2) AngII (300 ng/kg), (3) AngII+losartan (Los; 10 mg/kg), (4) TQ (40 mg/kg)+AngII, and (5-7) three doses of N. sativa (200, 400, and 600 mg/kg)+AngII. Los and AngII were injected intravenously; TQ and extracts were injected intraperitoneally. In TQ and N. sativa-treated groups, 30 min after injection of the extract and TQ, AngII was injected. Cardiovascular parameters were recorded by power lab system after cannulation of femoral artery. The maximum changes (∆) of systolic blood pressure (SBP), mean arterial pressure (MAP), and heart rate (HR) were calculated and used for statistical analysis. Results AngII significantly increased maximal ∆SBP, ∆MAP, and ∆HR compared with the control (p<0.001), and these effects significantly were blunted by Los. TQ and two higher doses (400 and 600 mg/kg) of N. sativa significantly could antagonize effect of AngII on ∆SBP, ∆MAP (p<0.05 to p<0.001). AngII-induced changes of HR are also significantly decreased by TQ and dose 600 mg/kg of extract (p<0.01 and p<0.05, respectively). Conclusions The N. sativa and its component TQ have the beneficial effect on hypertension probably due to attenuation cardiovascular effects of AngII.

Nigella sativa L. (Black Cumin): A Promising Natural Remedy for Wide Range of Illnesses

The seed of Nigella sativa (N. sativa) has been used in different civilization around the world for centuries to treat various animal and human ailments. So far, numerous studies demonstrated the seed of Nigella sativa and its main active constituent, thymoquinone, to be medicinally very effective against various illnesses including different chronic illness: neurological and mental illness, cardiovascular disorders, cancer, diabetes, inflammatory conditions, and infertility as well as various infectious diseases due to bacterial, fungal, parasitic, and viral infections. In spite of limited studies conducted so far, the promising efficacy of N. sativa against HIV/AIDS can be explored as an alternative option for the treatment of this pandemic disease after substantiating its full therapeutic efficacy. Moreover, the strong antioxidant property of this valued seed has recently gained increasing attention with regard to its potential role as dietary supplement with minimal side effects. Besides, when combined with different conventional chemotherapeutic agents, it synergizes their effects resulting in reducing the dosage of concomitantly used drugs with optimized efficacy and least and/or no toxicity. A number of pharmaceutical and biological properties have been ascribed to seeds of N. sativa. The present review focuses on the profile of high-value components along with traditional medicinal and biological principles of N. sativa seed and its oil so as to explore functional food and nutraceutical potential of this valued herb.

The natural phenolic compounds as modulators of NADPH oxidases in hypertension

BACKGROUND

Hypertension is a major public health problem worldwide. It is an important risk factor for other cardiovascular diseases such as coronary artery disease, stroke, heart failure, atrial fibrillation, peripheral vascular disease, chronic kidney disease, and atherosclerosis.

PURPOSE

There is strong evidence that excess ROS-derived NADPH oxidase (NOX) is an important agent in hypertension. It augments blood pressure in the presence of other pro-hypertensive factors such as angiotensin II (Ang II), an important and potent regulator of cardiovascular NADPH oxidase, activates NOX via AT1 receptors. NADPH oxidase, a multi-subunit complex enzyme, is considered as a key source of ROS production in the vasculature. The activation of this enzyme is needed for assembling Rac-1, p^40phox, p^47phox and p^67phox subunits. Since, hypertensive patients need to control blood pressure for their entire life and because drugs and other chemicals often induce adverse effects, the use of natural phenolic compounds which are less toxic and potentially beneficial may be good avenues of addition research in our understand of the underlying mechanism involved in hypertension. This review focused on several natural phenolic compounds as berberine, thymoquinone, catechin, celastrol, apocynin, resveratrol, curcumin, hesperidine and G-hesperidine, and quercetin which are NOX inhibitors. In addition, structure activity relationship of these compounds eventually as the most inhibitors was discussed.

METHODS

This comprehensive review is based on pertinent papers by a selective search using relevant keywords that was collected using online search engines and databases such as ScienceDirect, Scopus and PubMed. The literature mainly focusing on natural products with therapeutic efficacies against hypertension via experimental models both in vitro and in vivo was identified.

RESULTS

It has been observed that these natural compounds prevent NADPH oxidase expression and ROS production while increasing NO bioavailability. It have been reported that they improve hypertension due to formation of a stable radical with ROS-derived NADPH oxidase and preventing the assembly of NOX subunites.

CONCLUSION

It is clear that natural phenolic compounds have some potential inhibitory effect on NADPH oxidase activity. In comparison to other phenolic plant compounds, the structural variability of the flavonoids should off different impacts on oxidative stress in hypertension including inhibition of nadph oxidase and direct scavenging of free radicals.

Nobiletin alleviates vascular alterations through modulation of Nrf-2/HO-1 and MMP pathways in l-NAME induced hypertensive rats

Nobiletin alleviates l-NAME-induced vascular dysfunction and remodeling and superoxide production in rats.

The predictive utility of the plant phylogeny in identifying sources of cardiovascular drugs

CONTEXT

Cardiovascular disease (CVD) is the number one cause of death globally, responsible for over 17 million (31%) deaths in the world. Novel pharmacological interventions may be needed given the high prevalence of CVD.

OBJECTIVE

In this study, we aimed to find potential new sources of cardiovascular (CV) drugs from phylogenetic and pharmacological analyses of plant species that have experimental and traditional CV applications in the literature.

MATERIALS AND METHODS

We reconstructed the molecular phylogeny of these plant species and mapped their pharmacological mechanisms of action on the phylogeny.

RESULTS

Out of 139 plant species in 71 plant families, seven plant families with 45 species emerged as phylogenetically important exhibiting common CV mechanisms of action within the family, as would be expected given their common ancestry: Apiaceae, Brassicaceae, Fabaceae, Lamiaceae, Malvaceae, Rosaceae and Zingiberaceae. Apiaceae and Brassicaceae promoted diuresis and hypotension; Fabaceae and Lamiaceae had anticoagulant/thrombolytic effects; Apiaceae and Zingiberaceae were calcium channel blockers. Moreover, Apiaceae, Lamiaceae, Malvaceae, Rosaceae and Zingiberaceae species were found to possess anti-atherosclerotic properties.

DISCUSSION AND CONCLUSIONS

The phylogeny identified certain plant families with disproportionately more species, highlighting their importance as sources of natural products for CV drug discovery. Though there were some species that did not show the same mechanism within the family, the phylogeny predicts that these species may contain undiscovered phytochemistry, and potentially, the same bioactivity. Evolutionary pharmacology, as applied here, may guide and expedite our efforts in discovering sources of new CV drugs.

Novel Potentials of the DPP-4 Inhibitor Sitagliptin against Ischemia-Reperfusion (I/R) Injury in Rat Ex-Vivo Heart Model

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a class of oral anti-diabetic drugs, implicated in pleiotropic secondary cardioprotective effects. The aim of the study was to unveil the unknown and possible cardioprotective targets that can be exerted by sitagliptin (Sitg) against ischemia-reperfusion (I/R) injury. Male wistar rats received 2 weeks’ Sitg oral treatment of different doses (25, 50, 100, and 150 mg/kg/day), or saline as a Control. Hearts were then isolated and subjected to two different I/R injury protocols: 10 min perfusion, 45 min regional ischemia, and 120 min reperfusion for infarct size (IS) measurement, or: 10 min perfusion, 45 min regional ischemia and 10 min reperfusion for biochemical analysis: nitric oxide synthases (NOSs) and DPP-4 activity, glucagon-like peptide-1 (GLP-1), Calcium, transient receptor potential vanilloid (TRPV)-1 and calcitonin gene-related peptide (CGRP) levels, transient receptor potential canonical (TRPC)-1 and e-NOS protein expression. NOS inhibitor (l-NAME) and TRPV-1 inhibitor (Capsazepine) were utilized to confirm the implication of both signaling mechanisms in DPP-4 inhibition-induced at the level of IS. Findings show that Sitg (50 mg) resulted in significant decrease in IS and DPP-4 activity, and significant increase in GLP-1, NOS activity, e-NOS expression, TRPV-1 level and TRPC-1 expression, compared to controls. Results of CGRP are in line with TRPV-1, as a downstream regulatory effect. NOS system and transient receptor potential (TRP) channels can contribute to DPP-4 inhibition-mediated cardioprotection against I/R injury using Sitagliptin.

Chrysin Pretreatment Improves Angiotensin System, cGMP Concentration in L-NAME Induced Hypertensive Rats

N^ω-nitro-l-arginine methyl ester (L-NAME) is a non-specific nitric oxide (NO) synthase inhibitor, commonly used for the induction of NO-deficient hypertension. The objective of the present study was to investigate the effects of chrysin with flavnoids, on L-NAME-induced hypertensive rats. Methods: An experimental hypertensive animal (180–220 g) model was induced by L-NAME intake on rats. In treatment chrysin was orally administered 25 mg/kg body weight (b.w.). Blood pressure was measured by tail cuff plethysmography system. Cardiac and vascular function was evaluated by Langendorff isolated heart system with Angiotensin II (Ang-II), Hexo oxygenase (HO-1), cyclic guanosine monophosphate (cGMP) concentration in tissues respectively. Rats with hypertension showed an elevated blood pressure (BP), left ventricular functions, ang II, and decreased cGMP concentration of tissues. Treatment of chrysin is reverse to near normal in left ventricular functions, Ang-II, Ho-1 and decreased cGMP concentration of tissues. The antihypertensive effect of chrysin appears to be mediated by a reduction in left ventricular functions, cardiac oxidative stress and Ang-II, an increase in cardiac HO-1, cGMP concentration and a prevention of plasma nitric oxide loss.

Dissecting the Potential Roles of Nigella sativa and Its Constituent Thymoquinone on the Prevention and on the Progression of Alzheimer's Disease

Several nutraceuticals have been investigated for preventing or retarding the progression of different neurodegenerative diseases, including Alzheimer's disease (AD). Because Nigella sativa (NS) and its isolated compound thymoquinone (TQ) have significant anti-oxidant and anti-inflammatory proprieties, they could represent effective neuroprotective agents. The purpose of this manuscript is to analyze and to recapitulate the results of in vitro and in vivo studies on the potential role of NS/TQ in AD's prevention and treatment. The level of evidence for each included animal study has been assessed by using a modified CAMARADES (Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies) 10-item checklist. We used MEDLINE and EMBASE databases to screen relevant articles published up to July 2017. A manual search was also performed. The database search yielded 38 studies, of which 18 were included in this manuscript. Results from these approaches suggest that NS or TQ could represent an effective strategy against AD due to the balancing of oxidative processes and the binding to specific intracellular targets. The overall effects mainly regard the prevention of hippocampal pyramidal cell loss and the increased cognitive functions.

Antihypertensive Effects of Roselle-Olive Combination in L-NAME-Induced Hypertensive Rats

This study aimed to evaluate the antihypertensive efficacy of a new combination therapy of Hibiscus sabdariffa and Olea europaea extracts (2 : 1; Roselle-Olive), using N(G)-nitro-L-arginine-methyl ester- (L-NAME-) induced hypertensive model. Rats received L-NAME (50 mg/kg/day, orally) for 4 weeks. Concurrent treatment with Roselle-Olive (500, 250, and 125 mg/kg/day for 4 weeks) resulted in a dose-dependent decrease in both systolic and diastolic blood pressure, reversed the L-NAME-induced suppression in serum nitric oxide (NO), and improved liver and kidney markers, lipid profile, and oxidative status. Furthermore, Roselle-Olive significantly lowered the elevated angiotensin-converting enzyme activity (ACE) and showed a marked genoprotective effect against oxidative DNA damage in hypertensive rats. Roselle-Olive ameliorated kidney and heart lesions and reduced aortic media thickness. Real-time PCR and immunohistochemistry showed an enhanced endothelial nitric oxide synthase (eNOS) gene and protein expression in both heart and kidney of Roselle-Olive-treated rats. To conclude, our data revealed that Roselle-Olive is an effective combination in which H. sabdariffa and O. europaea synergistically act to control hypertension. These effects are likely to be mediated by antioxidant and genoprotective actions, ACE inhibition, and eNOS upregulation by Roselle-Olive constituents. These findings provide evidences that Roselle-Olive combination affords efficient antihypertensive effect with a broad end-organ protective influence.

Parkia speciosa empty pod prevents hypertension and cardiac damage in rats given N(G)-nitro-l-arginine methyl ester

Parkia speciosa Hassk is a plant found abundantly in Southeast Asia region. Its seeds with or without pods and roots have been used in traditional medicine in this region to treat hypertension. Therefore, we aimed to investigate the potential effect of the plant empty pod extract on hypertension development and changes in heart induced by N(G)-nitro-l-arginine methyl ester (l-NAME) administration in rats. Twenty-four male Sprague Dawley rats were divided into four groups. Groups 1 to 3 were given l-NAME (25mg/kg, intraperitoneally) for 8 weeks. Groups 2 and 3 were also given Parkia speciosa empty pods methanolic extract (800mg/kg, orally) and nicardipine (3mg/kg, orally), concurrently with l-NAME. The last group served as the control. l-NAME reduced plasma nitric oxide level and therefore, increased systolic blood pressure, angiotensin-converting enzyme and NADPH oxidase activities as well as lipid peroxidation in the heart. Parkia speciosa extract and nicardipine treatments had significantly prevented the elevations of blood pressure, angiotensin-converting enzyme, NADPH oxidase activities and lipid peroxidation in the heart induced by the l-NAME. Parkia speciosa extract but not nicardipine prevented the reduction in plasma nitric oxide level caused by l-NAME. In conclusion, Parkia speciosa empty pods methanolic extract has a potential to prevent the development of hypertension possibly by preventing the loss of plasma nitric oxide, as well as has cardioprotective effects by reducing angiotensin-converting enzyme activity and oxidative stress in the heart in rats administered l-NAME.

Vaccarin administration ameliorates hypertension and cardiovascular remodeling in renovascular hypertensive rats

Sympathetic overdrive, activation of renin angiotensin systems (RAS), and oxidative stress are vitally involved in the pathogenesis of hypertension and cardiovascular remodeling. We recently identified that vaccarin protected endothelial cell function from oxidative stress or high glucose. In this study, we aimed to investigate whether vaccarin attenuated hypertension and cardiovascular remodeling. Two-kidney one-clip (2K1C) model rats were used, and low dose of vaccarin (10 mg/kg), high dose of vaccarin (30 mg/kg), captopril (30 mg/kg) were intraperitoneally administrated. Herein, we showed that 2K1C rats exhibited higher systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), left ventricular mass/body weight ratio, myocardial hypertrophy or fibrosis, media thickness, and media thickness to lumen diameter, which were obviously alleviated by vaccarin and captopril. In addition, both vaccarin and captopril abrogated the increased plasma renin, angiotensin II (Ang II), norepinephrine (NE), and the basal sympathetic activity. The AT1R protein expressions, NADPH oxidase subunit NOX-2 protein levels and malondialdehyde (MDA) content were significantly increased, whereas superoxide dismutase (SOD) and catalase (CAT) activities were decreased in myocardium, aorta, and mesenteric artery of 2K1C rats, both vaccarin and captopril treatment counteracted these changes in renovascular hypertensive rats. Collectively, we concluded that vaccarin may be a novel complementary therapeutic medicine for the prevention and treatment of hypertension. The mechanisms for antihypertensive effects of vaccarin may be associated with inhibition of sympathetic activity, RAS, and oxidative stress.

Role of Nigella sativa and Its Constituent Thymoquinone on Chemotherapy-Induced Nephrotoxicity: Evidences from Experimental Animal Studies

Background: Most chemotherapeutic drugs are known to cause nephrotoxicity. Therefore, new strategies have been considered to prevent chemotherapy-induced nephrotoxicity. It is of note that Nigella sativa (NS), or its isolated compound Thymoquinone (TQ), has a potential role in combating chemotherapy-induced nephrotoxicity. AIM: To analyze and report the outcome of experimental animal studies on the protective effects of NS/TQ on chemotherapy-associated kidney complications. Design: Standard systematic review and narrative synthesis. Data Sources: MEDLINE, EMBASE databases were searched for relevant articles published up to March 2017. Additionally, a manual search was performed. Criteria for a study’s inclusion were: conducted in animals, systematic reviews and meta-analysis, containing data on nephroprotective effects of NS/TQ compared to a placebo or other substance. All strains and genders were included. Results: The database search yielded 71 studies, of which 12 (cisplatin-induced nephrotoxicity 8; methotrexate-induced nephrotoxicity 1; doxorubicin-induced nephrotoxicity 2; ifosfamide-induced nephrotoxicity 1) were included in this review. Conclusions: Experimental animal studies showed the protective effect of NS, or TQ, on chemotherapy-induced nephrotoxicity. These effects are caused by decreasing lipid peroxidation and increasing activity of antioxidant enzymes in renal tissue of chemotherapy-treated animals.

Effects of Nigella sativa on apoptosis and GABAA receptor density in cerebral cortical and hippocampal neurons in pentylenetetrazol induced kindling in rats

We investigated the effects of Nigella sativa on apoptosis and gamma-aminobutyric acid (GABA_A) receptor density in cerebral cortical and hippocampal neurons in a pentylenetetrazol (PTZ)-induced kindling model in rats. The PTZ kindling model was produced by injecting PTZ in subconvulsive doses to rats on days 1, 3, 5, 8, 10, 12, 15, 17, 19, 22 and 24 of the study into animals of PTZ treated (PTZ) and PTZ + N. sativa treated (PTZ + NS) groups. Clonic and tonic seizures were induced by injecting a convulsive dose of PTZ on day 26 of the study. Rats in the PTZ + NS group were treated also with a 10 mg/kg methanolic extract of N. sativa 2 h before each PTZ injection. Rats in the control group were treated with 4 ml/kg saline. The number of neurons that expressed GABA_A receptors in the hippocampus and cerebral cortex of rats in the PTZ and PTZ + NS groups increased significantly. There was no significant difference in the number of GABA_A receptors between the PTZ and PTZ + NS groups. GABA_A receptor density of the neurons in the cerebral cortex, but not hippocampus, was increased in PTZ group compared to controls. We observed a significant increase in the number of apoptotic neurons in the cerebral cortex of rats of both the PTZ and PTZ + NS groups compared to controls. We observed a significant decrease in the number of the apoptotic neurons in the cerebral cortex of rats in the PTZ + NS group compared to the PTZ group. N. sativa treatment ameliorated the PTZ induced neurodegeneration in the cerebral cortex as reflected by neuronal apoptosis and neuronal GABA_A receptor frequency.