Potential of garlic and its active constituent, S-allyl cysteine, as antihypertensive and cardioprotective in presence of captopril

Garlic and Hypertension: Efficacy, Mechanism of Action, and Clinical Implications

Hypertension is a major risk factor for heart disease and stroke. Garlic has a long history of use in traditional medicine for various conditions, including hypertension. This narrative review examined the scientific evidence on the efficacy of garlic in lowering blood pressure. It explores the historical uses of garlic in different cultures for medicinal purposes and delves into the phytochemical composition of garlic, highlighting key components, like allicin and ajoene, that are believed to contribute to its potential health benefits. Clinical studies that investigated the effects of garlic and garlic-based supplements on blood pressure are presented, with the findings suggesting that garlic consumption may modestly reduce blood pressure, particularly in individuals with mild hypertension. Potential mechanisms of action include increased nitric oxide production, improved endothelial function, and antioxidant properties. While garlic may offer some benefits for blood pressure management, it should not be considered a substitute for conventional antihypertensive medications. Further large-scale, long-term clinical trials are warranted to establish the efficacy of garlic in managing hypertension, including the optimal dosage and formulation.

Garlic bioactive substances and their therapeutic applications for improving human health: a comprehensive review

Garlic (Allium sativum L.) is a widely abundant spice, known for its aroma and pungent flavor. It contains several bioactive compounds and offers a wide range of health benefits to humans, including those pertaining to nutrition, physiology, and medicine. Therefore, garlic is considered as one of the most effective disease-preventive diets. Many in vitro and in vivo studies have reported the sulfur-containing compounds, allicin and ajoene, for their effective anticancer, anti-diabetic, anti-inflammatory, antioxidant, antimicrobial, immune-boosting, and cardioprotective properties. As a rich natural source of bioactive compounds, including polysaccharides, saponins, tannins, linalool, geraniol, phellandrene, β-phellandrene, ajoene, alliin, S-allyl-mercapto cysteine, and β-phellandrene, garlic has many therapeutic applications and may play a role in drug development against various human diseases. In the current review, garlic and its major bioactive components along with their biological function and mechanisms of action for their role in disease prevention and therapy are discussed.

Natural angiotensin converting enzyme inhibitors: A safeguard against hypertension, respiratory distress syndrome, and chronic kidney diseases

Hypertension is a serious concern as it is one of the causes of kideny failure and pulmonary fibrosis. An important therapeutic strategy for treating chronic hypertension is to inhibit the angiotensin converting enzyme (ACE). ACE inhibition reduces kidney damage, pulmonary artery pressure, and high blood pressure. Due to their high efficacy and low risk of side effects, natural renin-angiotensin system inhibitors have drawn increasing attention over the past decades. Alkaloids, amino acids, anthocyanidins, flavonoids, glucosinolates, isoflavonoids, phenolic acids, polyphenolics, and triterpenoids are among the bioactive metabolites pocessing an impressive ACE inhibitory activity. Many herbs including Rosmarinus officinalis, Hibiscus sabdariffa, Curcuma longa, Rauwolfia serpentina, Emblica officinalis, Cynara scolymus, Punica granatum, Mucuna pruriens, Capsicum annuum, and Moringa olifera were found having ACE inhibitory activities comparable to captopril and enalpril. These enticing natural ACE inhibitors deserve to be a safeguard medicine against hypertension, respiratory distress syndrome, and chronic kidney diseases. More clinical trials are required before new natural compounds and herbs can be used to treat chronic hypertension and its ramifications, such as respiratory distress syndrome and kidney failure.

Targeting the adenosine monophosphate-activated protein kinase signalling pathway by bempedoic acid attenuates Angiotensin II-induced cardiac remodelling in renovascular hypertension in rats

The crosstalk between the renin-angiotensin system and Adenosine monophosphate-activated protein kinase (AMPK) gained significant interest due to their involvement in the pathogenesis of several cardiovascular diseases. Angiotensin II (Ang II) plays a crucial role in developing cardiac remodelling by inducing energy imbalance, inflammation, oxidative and endoplasmic reticulum stress, and transforming growth factor-β (TGF-β)-induced fibrosis. Ang II directly or through extracellular signal-regulated kinase (ERK) activation impairs AMPK signalling with well-known antioxidant, anti-inflammatory, and anti-fibrotic effects.

AIM

This study aimed to investigate the role of bempedoic acid, a novel antihyperlipidemic drug, in attenuating hypertension-induced cardiac remodelling in rats by modulating Ang II-induced damage and activating the AMPK signalling pathway.

METHOD

Sixty adult male Sprague Dawley rats were randomly allocated into the Sham control group, Hypertensive group, Captopril group (30 mg/kg), and Bempedoic acid group (30 mg/kg). Hypertension was induced by left renal artery ligation in all groups except the Sham control group. Treatment with captopril and bempedoic acid started 14 days post-surgy and lasted two weeks. Finally, Hemodynamic measurements and electrocardiographic examination were done followed by heart tissue samples collection for biochemical, histopathological, and immunohistochemical examinations.

KEY FINDINGS

Bempedoic acid preserved the cardiac function and electrocardiogram patterns. It inhibited endoplasmic reticulum stress, exhibited antioxidant activity, and increased endothelial nitric oxide synthase activity. Bempedoic acid interfered with ERK signalling pathways, including nuclear factor-κB and TGF-β, exerting anti-inflammatory and anti-fibrotic effects.

SIGNIFICANCE

These findings indicate the cardioprotective and antihypertrophic activity of bempedoic acid, which are suggested to result from energy-independent AMPK downstream signalling activation.

Techno-Functional Properties of Burgers Fortified by Wild Garlic Extract: A Reconsideration

The aim of this research was to examine the chemical properties of freshly squeezed wild garlic extract (FSWGE) and its use as an additive in burgers (BU). Technological and sensory properties of such fortified burgers (BU) were determined. LC-MS/MS analyses identified thirty-eight volatile BAC. Allicin prevalence (11.375 mg/mL) is the key parameter determining the amount of FSWGE added in raw BU (PS-I 1.32 mL/kg, PS-II 4.40 mL/kg, and PS-III 8.79 mL/kg). Minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) values of the FSWGE and evaporated FSWGE (EWGE) were determined against the six microorganisms using a microdilution method. The data indicated that using FSWGE can result in a reduced risk of Serratia marcescens (MIC = 50 mg/mL; MBC = 60 mg/mL), Listeria monocytogenes (MIC = MBC = 90 mg/mL), Escherichia coli and Staphylococcus aureus (MIC = 90 mg/mL; MBC ≥ 100 mg/mL), and Salmonella enteritidis and Enterococcus faecium (MIC = 100 mg/mL; MBC > 100 mg/mL) in BU. Changes in antioxidant (AOX) capacity were followed during cold storage (up to 10 days) and freezing (90 days). It was shown that PS-III had the highest level of AOX capacity during the entire period of cold storage, revealing 8.79 mL FSWGE/kg BU as the most suitable effective concentration. Adding FSWGE did not negatively affect the technological and physico-chemical properties during both cold and freeze storage. Regarding sensory evaluation, modified BU received mostly higher scores compared to control. The results of this study have demonstrated the great potential of wild garlic extract usage in the creation of safe products with prolonged shelf life.

Effect of bempedoic acid on angiotensin-II induced hypertension and vascular tissue remodelling in renal hypertensive rats through AMPK multiple signalling pathways modulation

Angiotensin II (Ang II), the effector of the renin-angiotensin system (RAS), is a key player in the pathogenesis of chronic hypertension, accompanied by vascular tissue resistance, remodelling, and damage. Chronic activation of Ang II receptor 1 (AT-1R) impairs multiple cellular targets implicated in cellular protection and survival, including adenosine Monophosphate-activated protein kinase (AMPK) signalling. In addition, it induces oxidative damage, endoplasmic reticulum (ER) stress, and fibrotic changes in resistance vessels. Our study investigated the antihypertensive and antifibrotic effects of bempedoic acid, a first-in-class antihyperlipidemic drug that targets adenosine triphosphate-citrate lyase enzyme to inhibit cholesterol synthesis. We also studied the modulation of multiple AMPK signalling pathways by bempedoic acid in a chronic hypertension model in rats. Sixty male Sprague-Dawley rats were divided into four groups: sham group, hypertensive group, standard captopril group, and bempedoic treated group. All groups underwent left renal artery ligation except the sham group. Fourteen days post-surgery, captopril and bempedoic acid were administered with a dose of 30 mg/kg/day orally to captopril-standard and bempedoic acid-treated groups for two weeks, respectively. In mesenteric resistance arteries, bempedoic acid activated AMPK energy independently and augmented AMPK multiple cellular targets to adapt to Ang II-induced cellular stress. It exerted antioxidant activity, increased endothelial nitric oxide synthase, and reversed the ER stress. Bempedoic acid maintained vascular integrity and prevented vascular remodelling by inhibiting extracellular signal-regulated kinase (ERK)/transforming growth factor-β fibrotic pathway. These effects were reflected in the improved hemodynamic measurements.

The Effect of Nonthermal Pretreatment on the Drying Kinetics and Quality of Black Garlic

Black garlic is obtained from regular garlic (Allium sativum L.) through the aging process and consequently gains many health-promoting properties, including antidiabetic and antioxidant. However, the material is still prone to microbiological deterioration and requires a long time to dry due to its properties. Therefore, this study aimed to investigate the effect of various drying methods on the quality of black garlic as well as determine the influence of selected nonthermal pretreatments on the drying kinetics and quality of black garlic, which is especially important in the case of the materials that are difficult to dry. The Weibull model was chosen to describe drying kinetics. Additionally, color, water activity together with antioxidant activity, phenolic compounds, and antidiabetic potential were determined. This study found that the application of a pulsed electric field (PEF), a constant electric field (CEF) as well as a magnetic field (MF) significantly reduced the time of drying (by 32, 40, and 24 min for a PEF, a CEF, and a MF, respectively, compared to combined drying without the pretreatment), and resulted in high antidiabetic potential. However, the highest content of phenolic compounds (1123.54 and 1125.36 mg/100 g dm for VMD125 and CD3h-VMD, respectively) and antioxidant capacity (ABTS = 6.05 and 5.06 mmol Trolox/100 g dm for VMD500 and CD6h-VMD, respectively) were reported for black garlic treated by vacuum-microwave drying and combined convective pre-drying followed by vacuum-microwave drying. Overall, the nonthermal pretreatment decreased the time of drying and showed very good efficiency in maintaining the antidiabetic potential of black garlic, especially in the case of the materials pretreated by a constant electric field (IC50 = 99 and 56 mg/mL, for α-amylase and α-glucosidase, respectively).

Effect of garlic extract on markers of lipid metabolism and inflammation in coronary artery disease (CAD) patients: A systematic review and meta-analysis

Several preclinical studies have focused on the beneficial effects of garlic on cardiovascular diseases, but the results were inconsistent. We performed a systematic review and meta-analysis on the effect of garlic powder tablets and aged garlic extract (AGE) in CAD patients, mainly focusing on blood pressure, coronary artery calcification, lipid profile, and inflammatory markers. We searched PubMed, Cochrane CENTRAL, and Google Scholar to identify randomized controlled trials which examined garlic's effect on CAD patients. The standardized mean difference with 95% CI was calculated using fixed-effect or random-effect models. Garlic has shown statistically significant changes of HDL (SMD = 0.18; 95% CI = -0.00 to 0.37; p = .05); LDL (SMD = -0.27; 95% CI = -0.46 to -0.08; p = .004), apolipoprotein-A (SMD = 0.68; 95% CI = 0.24 1.13; p = .002), C-RP (SMD = -0.59; 95% CI = -0.92 to -0.25; p = .0007), IL-6 (SMD = -1.08; 95% CI = -2.17 to 0.01; p = .05), homocysteine (SMD = -0.66; 95% CI = -1.04 to -0.28; p = .0007) and CAC score (SMD = -1.61; 95% CI = -2.66 to -0.57; p = .003). In the case of subgroup analysis, the overall effect was significantly effective in reducing TC, LDL levels and improving HDL levels in CV risk patients. Our study findings provide consistent evidence that intake of garlic reduces CVD risk factors. However, garlic could be considered a safe natural medicine to debilitate inflammation in CAD patients.

The Allium triquetrum L. Leaves Mitigated Hepatotoxicity and Nephrotoxicity Induced by Lead Acetate in Wistar Rats

The aim of this study was to scrutinize the possible mitigating role of leaves' Allium triquetrum L. against the toxicity of lead acetate on liver and kidney markers of Wistar rat. Lead acetate (Pb) and leaves' aqueous extracts (L) were orally administrated for 3 weeks. Rats were divided into the control, Pb group (500 mg/kg body weight/day), positive controls L (2g, 3g, 4g/kg BW/day), along with three combined groups of the same doses (Pb-L1, Pb-L2, Pb-L3). The levels of plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total proteins (TP), albumin (ALB), urea, creatinine (Cr), and uric acid (UA), as well as the hepatic and the renal malondialdehyde (MDA), glutathione (GSH), and glutathione peroxidase (GPx), were estimated. Results exhibited a significant increase in plasma AST, ALT, ALP, urea, creatinine, uric acid, and MDA levels of the Pb group compared to the control, with the exception of TP, ALB, GSH levels, and GPx activities that were significantly diminished, though the co-administration of garlic extracts (Pb-L) revealed a significant decrease in all mentioned markers, excluding the TP, ALB, GSH, and GPx levels. Likewise, Pb caused histological injuries in the hepatic and renal tissues of rats, while the co-administration of leaves' wild garlic has reduced such effect. Thought, the Pb-L has attenuated the Pb-induced toxicity in a dose-dependent manner. In conclusion, the aqueous extracts of A. triquetrum have the potential to alleviate Pb hepatotoxicity and nephrotoxicity through the modulation of most biomarkers in Wistar rat.

Health-promoting foods and food crops of West-Africa origin: The bioactive compounds and immunomodulating potential

The rural communities of the sub-Sahara regions in Africa are rich in diverse indigenous culinary knowledge and foods, food crops, and condiments such as roots/tubers, cereal, legumes/pulses, locust beans, and green leafy vegetables. These food crops are rich in micronutrients and phytochemicals, which have the potentials to address hidden hunger as well as promote health when consumed. Some examples of these are fermented foods such as ogi and plants such as Vernonia amygdalina (bitter leaf), Zingiber officinales (garlic), Hibiscus sabdariffa (Roselle), and condiments. Food crops from West Africa contain numerous bioactive substances such as saponins, alkaloids, tannins, phenolics, flavonoids, and monoterpenoid chemicals among others. These bioresources have proven biological and pharmacological activities due to diverse mechanisms of action such as immunomodulatory, anti-inflammatory, antipyretic, and antioxidant activities which made them suitable as candidates for nutraceuticals and pharma foods. This review seeks to explore the different processes such as fermentation applied during food preparation and food crops of West-African origin with health-promoting benefits. The different bioactive compounds present in such food or food crops are discussed extensively as well as the diverse application, especially regarding respiratory diseases. PRACTICAL APPLICATIONS: The plants and herbs summarized here are more easily accessible and affordable by therapists and others having a passion for promising medicinal properties of African-origin plants.The mechanisms and unique metabolic potentials of African food crops discussed in this article will promote their applicability as a template molecule for novel drug discoveries in treatment strategies for emerging diseases. This compilation of antiviral plants will help clinicians and researchers bring new preventive strategies in combating COVID-19 like viral diseases, ultimately saving millions of affected people.

Natural Products in Cardiovascular Diseases: The Potential of Plants from the Allioideae Subfamily (Ex-Alliaceae Family) and Their Sulphur-Containing Compounds

Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide and, together with associated risk factors such as diabetes, hypertension, and dyslipidaemia, greatly impact patients' quality of life and health care systems. This burden can be alleviated by fomenting lifestyle modifications and/or resorting to pharmacological approaches. However, due to several side effects, current therapies show low patient compliance, thus compromising their efficacy and enforcing the need to develop more amenable preventive/therapeutic strategies. In this scenario, medicinal and aromatic plants are a potential source of new effective agents. Specifically, plants from the Allioideae subfamily (formerly Alliaceae family), particularly those from the genus Allium and Tulbaghia, have been extensively used in traditional medicine for the management of several CVDs and associated risk factors, mainly due to the presence of sulphur-containing compounds. Bearing in mind this potential, the present review aims to gather information on traditional uses ascribed to these genera and provide an updated compilation of in vitro and in vivo studies validating these claims as well as clinical trials carried out in the context of CVDs. Furthermore, the effect of isolated sulphur-containing compounds is presented, and whenever possible, the relation between composition and activity and the mechanisms underlying the beneficial effects are pointed out.

Bioactive Natural Products against Systemic Arterial Hypertension: A Past 20-Year Systematic and Prospective Review

Background. Systemic arterial hypertension is one of the most common cardiovascular risks, corresponding to 45% of deaths involving CVDs. The use of natural products, such as medicinal plants, belongs to a millennial part of human therapeutics history and has been employed as an alternative anti-hypertensive treatment. Objective. The present review aims to prospect some natural products already experimentally assayed against arterial hypertension through scientific virtual libraries and patent documents over the past 20 years. Search strategy. This is a systematic review of the adoption of the PRISMA protocol and a survey of the scientific literature that synthesizes the results from published articles between 2001 and 2020 concerning the use of medicinal plants in the management of hypertension, including which parts of the plant or organism are used, as well as the mechanisms of action underlying the anti-hypertensive effect. Furthermore, a technological prospection was also carried out in patent offices from different countries in order to check technologies based on natural products claimed for the treatment or prevention of hypertension. Inclusion criteria. Scientific articles where a natural product had been experimentally assayed for anti-hypertensive activity (part of plants, plant extracts, and products derived from other organisms) were included. Data extraction and analysis. The selected abstracts of the articles and patent documents were submitted to a rigorous reading process. Those articles and patents that were not related to anti-hypertensive effects and claimed potential applications were excluded from the search. Results. Eighty specimens of biological species that showed anti-hypertensive activity were recovered, with 01 representative from the kingdom Fungi and 02 from the kingdom Protista, with emphasis on the families Asteraceae and Lamiaceae, with 6 representatives each. Leaves and aerial parts were the most used parts of the plants for the extraction of anti-hypertensive products, with maceration being the most used extraction method. Regarding phytochemical analyses, the most described classes of biomolecules in the reviewed works were alkaloids, terpenes, coumarins, flavonoids, and peptides, with the reduction of oxidative stress and the release of NO among the mechanisms of action most involved in this process. Regarding the number of patent filings, China was the country that stood out as the main one, with 813 registrations. Conclusion. The anti-hypertensive activity of natural products is still little explored in Western countries. Besides, China and India have shown more results in this area than other countries, confirming the strong influence of traditional medicine in these countries.

Garlic: A systematic review of the effects on cardiovascular diseases

Allium sativum (garlic) certainly is one of the oldest horticultural crops in the world and presents bioactive compounds that are related to the garlic's effects on human health. Several authors have shown beneficial effects on diabetes, hypertension, dyslipidemia, obesity, and cardiovascular diseases (CVD), which are among the most relevant causes of mortality in the world. The aim of this systematic review was to evaluate the effects of garlic in the risk factors of CVD and evaluate its economic importance. MEDLINE-PubMed, COCHRANE, EMBASE, and Google Scholar databases were searched. The included studies showed that the use of garlic can reduce blood pressure, waist circumference, body mass index, LDL-c, non-HDL-c, total cholesterol, triglycerides, and inflammatory markers. It also can increase the levels of HDL-c and can improve cardiovascular parameters such as coronary artery calcium, microcirculation, epicardial and periaortic adipose tissue, post occlusive reactive hyperemia, low attenuation plaque, carotid intima-media thickness; and carotid intima-media thickness. Due to these reasons, garlic can be considered in the prevention and treatment of CVD risk factors.

Virtual screening of functional foods and dissecting their roles in modulating gene functions to support post COVID-19 complications

COVID-19 has become the focal point since 2019 after the outbreak of coronavirus disease. Many drugs are being tested and used to treat coronavirus infections; different kinds of vaccines are also introduced as preventive measure. Alternative therapeutics are as well incorporated into the health guidelines of some countries. This research aimed to look into the underlying mechanisms of functional foods and how they may improve the long-term post COVID-19 cardiovascular, diabetic, and respiratory complications through their bioactive compounds. The potentiality of nine functional foods for post COVID-19 complications was investigated through computational approaches. A total of 266 bioactive compounds of these foods were searched via extensive literature reviewing. Three highly associated targets namely troponin I interacting kinase (TNNI3K), dipeptidyl peptidase 4 (DPP-4), and transforming growth factor beta 1 (TGF-β1) were selected for cardiovascular, diabetes, and respiratory disorders, respectively, after COVID-19 infections. Best docked compounds were further analyzed by network pharmacological tools to explore their interactions with complication-related genes (MAPK1 and HSP90AA1 for cardiovascular, PPARG and TNF-alpha for diabetes, and AKT-1 for respiratory disorders). Seventy-one suggested compounds out of one-hundred and thirty-nine (139) docked compounds in network pharmacology recommended 169 Gene Ontology (GO) items and 99 Kyoto Encyclopedia of Genes and Genomes signaling pathways preferably AKT signaling pathway, MAPK signaling pathway, ACE2 receptor signaling pathway, insulin signaling pathway, and PPAR signaling pathway. Among the chosen functional foods, black cumin, fenugreek, garlic, ginger, turmeric, bitter melon, and Indian pennywort were found to modulate the actions. Results demonstrate that aforesaid functional foods have attenuating roles to manage post COVID-19 complications. PRACTICAL APPLICATIONS: Functional foods have been approaching a greater interest due to their medicinal uses other than gastronomic pleasure. Nine functional food resources have been used in this research for their traditional and ethnopharmacological uses, but their directive-role in modulating the genes involved in the management of post COVID-19 complications is inadequately studied and reported. Therefore, the foods types used in this research may be prioritized to be used as functional foods for ameliorating the major post COVID-19 complications through appropriate science.

A review of some common African spices with antihypertensive potential

Hypertension is the most common non-communicable disease, with about 1.28 billion hypertensive people worldwide. It is more prevalent in men than women and more common in the elderly. Hereditary, age, obesity, lifestyle, diet, alcohol, and chronic metabolic diseases are the major risk factors of hypertension. Treating hypertension is a complex process as there are several mechanisms responsible for its pathogenesis; hence, a combination of several drugs is used for managing hypertension. Drugs used in managing hypertension are expensive and often come with associated side effects; thus, there is need for alternative means of managing this life-threatening disease. These drugs do not achieve the recommended blood pressure target in most people; more so majority of people with hypertension do not follow the treatment regimen religiously. Some Africans have been reported to become normotensive as a result of dietary consumption of spices. Several spices have been used over the years in Africa to manage hypertension. The aim of this review is to evaluate the ethnomedicinal use, bioactive phytochemical composition, bioactive compounds present, and pharmacological applications of spices commonly used in Africa for managing hypertension. Most of the plants used contained polyphenols, flavonoids, tannins, anthraquinone, flavonoids, cardiac glycosides, and saponins. Dietary supplementation of Xylopia aethiopica and other spices in diet have been proven to significantly reduced plasma angiotensin-I-converting enzyme (ACE) than simvastatin (the reference drug). Toxicological, histological, and hematological evaluation revealed that acute and chronic consumption of most of these spices are safe. Studies have also revealed that some of the spices can be used as alternative therapy alongside usual antihypertensive medications. PRACTICAL IMPLICATION: The prevalent rate of hypertension is on the increase in both the developed and developing countries. People often skip medication due to their busy schedule and anti-hypertensive potential side effects; however, this is not the case with food/spices as most people consumed them daily. Deliberate, right combinations and consistent incorporation of spices with proven anti-hypertensive potential into our diet may be of great benefit in normalizing blood pressure and mitigate other complications on the heart and vital organs.

Immunomodulatory effects of Allium Sativum L. and its constituents against viral infections and metabolic diseases

BACKGROUND

Allium sativum L., or garlic, is one of the most studied plants worldwide within the field of traditional medicine. Current interests lie in the potential use of garlic as a preventive measure and adjuvant treatment for viral infections, e.g., SARS-CoV-2. Even though it cannot be presented as a single treatment, its beneficial effects are beyond doubt. The World Health Organization has deemed it an essential part of any balanced diet with immunomodulatory properties.

OBJECTIVE

The aim of the study was to review the literature on the effects of garlic compounds and preparations on immunomodulation and viral infection management, with emphasis on SARS-CoV-2.

METHOD

Exhaustive literature search has been carried out on electronic databases.

CONCLUSION

Garlic is a fundamental part of a well-balanced diet which helps maintain general good health. The reported information regarding garlic's ability to beneficially modulate inflammation and the immune system is encouraging. Nonetheless, more efforts must be made to understand the actual medicinal properties and mechanisms of action of the compounds found in this plant to inhibit or diminish viral infections, particularly SARS-CoV-2. Based on our findings, we propose a series of innovative strategies to achieve such a challenge in the near future.

The Potential Benefits of Using Garlic Oil and Its Active Constituent, Dially Disulphide, in Combination With Carvedilol in Ameliorating Isoprenaline-Induced Cardiac Damage in Rats

Garlic oil and its primary component, diallyl disulphide (DADS), were tested in rats with isoprenaline (ISO) induced myocardial infarction for cardioprotective benefits when combined with carvedilol. Garlic oil (GO) was administered to rats (Sprague-dawley strain) at two doses of 50 and 100 mg/kg body weight, whereas DADS was given in two doses of 4.47 and 8.94 mg/kg, respectively. The animals were given oral doses of garlic oil and DADS on alternate days for 3 weeks, either alone or in combination with carvedilol (2 mg/kg). Cardiac injury was done by administering two doses of isoprenaline (150 mg/kg, sc) to all treated groups except the first, which served as a control. Biomarkers of cardiac injury and histological investigations were studied for their potential in reducing ISO-induced myocardial damage. Animals pretreated with GO, DADS, and carvedilol had significantly (p < 0.01) lowered heart weight and heart to body weight ratio. In rats treated with carvedilol plus high dosages of garlic oil (100 mg/kg, p.o) and DADS (8.94 mg/kg, p.o) compared to the ISO control and carvedilol group, the activities of SOD and Catalase were enhanced in cardiac tissue homogenate. When compared to ISO control and carvedilol group, the activities of LDH and CK-MB were elevated in heart tissue homogenate with a simultaneous reduction in their serum levels in animals treated with a combination of carvedilol with high doses of garlic oil (100 mg/kg, p.o) and DADS (8.94 mg/kg, p.o). Overall, combining garlic oil or DADS with carvedilol improved the cardioprotective effect of carvedilol and protected rats from ISO-induced myocardial infarction. However, more research is needed to establish the mechanism of garlic oil and DADS interaction with carvedilol.

Cardioprotective Potential of Garlic Oil and Its Active Constituent, Diallyl Disulphide, in Presence of Carvedilol during Chronic Isoprenaline Injection-Mediated Myocardial Necrosis in Rats

In isoprenaline (ISO)-induced myocardial infarcted rats, garlic oil (GO) and its main ingredient, diallyl disulfide (DADS), were examined for cardioprotective effects when used with carvedilol (CAR). GO, DADS and CAR were given to rats in their respective groups, either alone or together, with the addition of isoprenaline (3 mg/kg/day, subcutaneously) during the last 10 days of treatment. At the end of 14 days of treatment, blood samples were collected, the hearts were excised under anesthesia and weighed. Heart tissue homogenate was used to measure superoxide dismutase (SOD), catalase (CAT), and thiobarbituric acid reactive substances (TBARS). Furthermore, the serum activities of cardiac markers, including lactate dehydrogenase, creatine kinase, and cardiac troponin, were checked. Moreover, inflammatory markers including tumor necrosis factor alpha, interleukin one beta, interleukin six, and kappa bp65 subunit were assessed. Rats that received GO, DADS, and CAR exhibited a significant increase in the cardiac antioxidant enzyme activities with a simultaneous decrease in serum cardiac markers enzymes and inflammatory markers. The TBARS were significantly reduced in rats that received treatment. The addition of carvedilol to GO or DADS significantly elevated antioxidant activities and decreased the release of cardiac enzymes into blood circulation. Both DADS and GOl were almost similar in efficacy, indicating the potential role of DADS in garlic oil-mediated cardioprotection. Combining GO or DADS with CAR increased CAR’s cardioprotective impact and protected rats from developing ISO-induced myocardial infarction.

Spices, Condiments, Extra Virgin Olive Oil and Aromas as Not Only Flavorings, but Precious Allies for Our Wellbeing

Spices, condiments and extra virgin olive oil (EVOO) are crucial components of human history and nutrition. They are substances added to foods to improve flavor and taste. Many of them are used not only to flavor foods, but also in traditional medicine and cosmetics. They have antioxidant, antiviral, antibiotic, anticoagulant and antiinflammatory properties and exciting potential for preventing chronic degenerative diseases such as cardiomyopathy and cancer when used in the daily diet. Research and development in this particular field are deeply rooted as the consumer inclination towards natural products is significant. It is essential to let consumers know the beneficial effects of the daily consumption of spices, condiments and extra virgin olive oil so that they can choose them based on effects proven by scientific works and not by the mere illusion that plant products are suitable only because they are natural and not chemicals. The study begins with the definition of spices, condiments and extra virgin olive oil. It continues by describing the pathologies that can be prevented with a spicy diet and it concludes by considering the molecules responsible for the beneficial effects on human health (phytochemical) and their eventual transformation when cooked.

Cytoprotective Potential of Aged Garlic Extract (AGE) and Its Active Constituent, S-allyl-l-cysteine, in Presence of Carvedilol during Isoproterenol-Induced Myocardial Disturbance and Metabolic Derangements in Rats

This study was conducted to determine the potential interaction of aged garlic extract (AGE) with carvedilol (CAR), as well as to investigate the role of S-allyl-l-cysteine (SAC), an active constituent of AGE, in rats with isoproterenol (ISO)-induced myocardial dysfunction. At the end of three weeks of treatment with AGE (2 and 5 mL/kg) or SAC (13.1 and 32.76 mg/kg), either alone or along with CAR (10 mg/kg) in the respective groups of animals, ISO was administered subcutaneously to induce myocardial damage. Myocardial infarction (MI) diagnostic predictor enzymes, lactate dehydrogenase (LDH) and creatinine kinase (CK-MB), were measured in both serum and heart tissue homogenates (HTH). Superoxide dismutase (SOD), catalase, and thiobarbituric acid reactive species (TBARS) were estimated in HTH. When compared with other groups, the combined therapy of high doses of AGE and SAC given alone or together with CAR caused a significant decrease in serum LDH and CK-MB activities. Further, significant rise in the LDH and CK-MB activities in HTH was noticed in the combined groups of AGE and SAC with CAR. It was also observed that both doses of AGE and SAC significantly increased endogenous antioxidants in HTH. Furthermore, histopathological observations corroborated the biochemical findings. The cytoprotective potential of SAC and AGE were dose-dependent, and SAC was more potent than AGE. The protection offered by aged garlic may be attributed to SAC. Overall, the results indicated that a high dose of AGE and its constituent SAC, when combined with carvedilol, has a synergistic effect in preventing morphological and physiological changes in the myocardium during ISO-induced myocardial damage.

S-allyl Cysteine Enhances Testosterone Production in Mice and Mouse Testis-Derived I-10 Cells

Hypogonadism, associated with low levels of testosterone synthesis, has been implicated in several diseases. Recently, the quest for natural alternatives to prevent and treat hypogonadism has gained increasing research interest. To this end, the present study explored the effect of S-allyl cysteine (SAC), a characteristic organosulfur compound in aged-garlic extract, on testosterone production. SAC was administered at 50 mg/kg body weight intraperitoneally into 7-week-old BALB/c male mice in a single-dose experiment. Plasma levels of testosterone and luteinizing hormone (LH) and testis levels of proteins involved in steroidogenesis were measured by enzymatic immunoassay and Western blot, respectively. In addition, mouse testis-derived I-10 cells were also used to investigate the effect of SAC on steroidogenesis. In the animal experiment, SAC significantly elevated testosterone levels in both the plasma and the testis without changing the LH level in plasma and increased phosphorylated protein kinase A (p-PKA) levels. Similar results were also observed in I-10 cells. The findings demonstrating the increasing effect of SAC on p-PKA and mRNA levels of Cyp11a suggest that SAC increases the testosterone level by activating the PKA pathway and could be a potential target for hypogonadism therapeutics.

S-allyl cysteine ameliorates heat stress-induced oxidative stress by activating Nrf2/HO-1 signaling pathway in BMECs

Heat stress-induced oxidative stress in bovine mammary epithelial cells (BMECs) threatens the normal growth and development of bovine mammary tissue, resulting in lower milk production of dairy cows. The aim of the present study is to investigate the protective effects of S-allyl cysteine (SAC), an organosulfur component extracted from aged garlic, on heat stress-induced oxidative stress and apoptosis in BMECs and to explore its underlying mechanisms. Our results showed that heat stress treatment considerably decreased cell viability, whereas SAC treatment dose-dependently restored cell viability of BMECs under heat-stress conditions. In addition, SAC protected BMECs from heat stress-induced oxidative damage by inhibiting the excessive accumulation of reactive oxygen species (ROS) and increasing the activity of antioxidant enzymes. It also inhibited heat stress-induced apoptosis by reducing the ratio of Bax/Bcl-2 and blocking proteolytic the cleavage of caspase-3 in BMECs. Interestingly, we found that the protective effect of SAC on heat stress-induced oxidative stress and apoptosis was dependent on the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway. SAC promoted the Nrf2 nuclear translocation in heat stress-induced BMECs. The results were also validated by Nrf2 and Keap1 knockdown experiments further demonstrating that Nrf-2 was indeed involved in the protective effect of SAC on heat stress-induced oxidative damage and apoptosis. In summary, our results showed that SAC could protect BMECs from heat stress-induced injury by mediating the Nrf2/HO-1 signaling pathway, suggesting that SAC could be considered as a therapeutic drug for attenuating heat stress-induced mammary gland diseases.

Garlic Derived Diallyl Trisulfide in Experimental Metabolic Syndrome: Metabolic Effects and Cardioprotective Role

This study aimed to examine the effects of diallyl trisulfide (DATS), the most potent polysulfide derived from garlic, on metabolic syndrome and myocardial function in rats with metabolic syndrome (MetS). For that purpose, we used 36 male Wistar albino rats divided into control rats, rats with MetS and MetS rats treated with 40 mg/kg of DATS every second day for 3 weeks. In the first part, we studied the impact of DATS on MetS control and found that DATS significantly raised H₂S, decreased homocysteine and glucose levels and enhanced lipid and antioxidative, while reducing prooxidative parameters. Additionally, this polysulfide improved cardiac function. In the second part, we investigated the impact of DATS on ex vivo induced ischemia/reperfusion (I/R) heart injury and found that DATS consumption significantly improved cardiodynamic parameters and prevented oxidative and histo-architectural variation in the heart. In addition, DATS significantly increased relative gene expression of eNOS, SOD-1 and -2, Bcl-2 and decreased relative gene expression of NF-κB, IL-17A, Bax, and caspases-3 and -9. Taken together, the data show that DATS can effectively mitigate MetS and have protective effects against ex vivo induced myocardial I/R injury in MetS rat.

Comparison Among Garlic, Berberine, Resveratrol,Hibiscus sabdariffa, GenusZizyphus, Hesperidin, Red Beetroot,Catha edulis,Portulaca oleracea, and Mulberry Leaves in the Treatment of Hypertension and Type 2 DM: A Comprehensive Review

Diabetes mellitus (DM) and hypertension are 2 of the most prevalent diseases with poor impact on health status worldwide. In most cases, they coexist with other metabolic disorders as well as cardiac, micro- and macrovascular complications. Many plants are known for their hypotensive, cardioprotective, and/or antidiabetic activities. Their active ingredients either identified and isolated or still utilized as herbal preparations of certain plant parts. The use of medicinal plants comprises the main basis for most of the traditional medicine (TM) systems and procedures. As conventional medicines seem insufficient to control such progressive diseases, herbal agents from TM could be used as adjuvant with good impact on disease control and progression as well as other concomitant health conditions. The aim of this study is to compare the efficacy of 10 different herbal medicines of botanical origin or herbal preparations in the management of hypertension and its cardiovascular complications and type 2 DM along with various coexisting health disorders. These herbal medicines are garlic, berberine, resveratrol, Hibiscus sabdariffa, Zizyphus ( oxyphylla, mucronate, jujube, rugosa), hesperidin, red beetroot, Catha edulis, mulberry leaves, and Portulaca oleracea.

Medicinal Plants as a Potential and Successful Treatment Option in the Context of Atherosclerosis

Atherosclerosis is a chronic multifactorial disease characterized by mainly changes of blood lipids profile and inflammation in vessel wall. The cardiovascular disease based on atherosclerosis is currently the leading cause of mortality in developed countries. Therefore, timely prevention and therapy of atherosclerosis are able to reduce the risk of the development of its clinical manifestations. Anti-atherosclerotic activity of medicinal plants mainly appears in their multiple effects such as anti-inflammatory, antioxidant, anti-atherogenic, hypotensive, lipid-lowering, anti-thrombotic. Moreover, most of medicinal plants are characterized by their pleiotropic anti-atherosclerotic action. In addition, the medicinal plants-derived pharmacological substances and/or compounds are characterized by relative safety and fewer side effects that allows considering them as one of potential anti-atherosclerotic effective agents. The direct anti-atherosclerotic effect of some medicinal plants was confirmed in clinical trials of carotid Intima-media thickness (IMT) progression during long-term medication with medicinal plants. This review attempted to determine the current status of the databases PubMed and Scopus (until November, 2019) to investigate the medicinal plants possessing anti-atherosclerotic activity in experimental and clinical studies.

Therapeutic effects of garlic in cardiovascular atherosclerotic disease

Garlic (Allium sativum) is a widely known medicinal plant, potential of which remains to be fully evaluated. Its wide-range beneficial effects appear to be relevant for treatment and prevention of atherosclerosis and related diseases. It is generally believed that garlic-based preparations are able to improve lipid profile in humans, inhibit cholesterol biosynthesis, suppress low density lipoprotein oxidation, modulate blood pressure, suppress platelet aggregation, lower plasma fibrinogen level and increase fibrinolytic activity, thus providing clinically relevant cardioprotective and anti-atherosclerotic effects. It is important to assess the level of evidence available for different protective effects of garlic and to understand the underlying mechanisms. This information will allow adequate integration of garlic-based preparations to clinical practice. In this review, we discuss the mechanisms of anti-atherosclerotic effects of garlic preparations, focusing on antihyperlipidemic, hypotensive, anti-platelet and direct anti-atherosclerotic activities of the medicinal plant. We also provide an overview of available meta-analyses and a number of clinical trials that assess the beneficial effects of garlic.

Antihypertensive phytocomplexes of proven efficacy and well-established use: Mode of action and individual characterization of the active constituents

Hypertension has become the leading risk factor for worldwide cardiovascular diseases. Conventional pharmacological treatment, after both dietary and lifestyle changes, is generally proposed. In this review, we present the antihypertensive properties of phytocomplexes from thirteen plants, long ago widely employed in ethnomedicines and, in recent years, increasingly evaluated for their activity in vitro and in vivo, also in humans, in comparison with synthetic drugs acting on the same systems. Here, we focus on the demonstrated or proposed mechanisms of action of such phytocomplexes and of their constituents proven to exert cardiovascular effects. Almost seventy phytochemicals are described and scientifically sound pertinent literature, published up to now, is summarized. The review emphasizes the therapeutic potential of these natural substances in the treatment of the 'high normal blood pressure' or 'stage 1 hypertension', so-named according to the most recent European and U.S. guidelines, and as a supplementation in more advanced stages of hypertension, however needing further validation by clinical trial intensification.

Bioactive Compounds and Biological Functions of Garlic (Allium sativum L.)

Garlic (Allium sativum L.) is a widely consumed spice in the world. Garlic contains diverse bioactive compounds, such as allicin, alliin, diallyl sulfide, diallyl disulfide, diallyl trisulfide, ajoene, and S-allyl-cysteine. Substantial studies have shown that garlic and its bioactive constituents exhibit antioxidant, anti-inflammatory, antibacterial, antifungal, immunomodulatory, cardiovascular protective, anticancer, hepatoprotective, digestive system protective, anti-diabetic, anti-obesity, neuroprotective, and renal protective properties. In this review, the main bioactive compounds and important biological functions of garlic are summarized, highlighting and discussing the relevant mechanisms of actions. Overall, garlic is an excellent natural source of bioactive sulfur-containing compounds and has promising applications in the development of functional foods or nutraceuticals for the prevention and management of certain diseases.

Bioactive Compounds and Biological Functions of Garlic (Allium sativum L.)

Garlic (Allium sativum L.) is a widely consumed spice in the world. Garlic contains diverse bioactive compounds, such as allicin, alliin, diallyl sulfide, diallyl disulfide, diallyl trisulfide, ajoene, and S-allyl-cysteine. Substantial studies have shown that garlic and its bioactive constituents exhibit antioxidant, anti-inflammatory, antibacterial, antifungal, immunomodulatory, cardiovascular protective, anticancer, hepatoprotective, digestive system protective, anti-diabetic, anti-obesity, neuroprotective, and renal protective properties. In this review, the main bioactive compounds and important biological functions of garlic are summarized, highlighting and discussing the relevant mechanisms of actions. Overall, garlic is an excellent natural source of bioactive sulfur-containing compounds and has promising applications in the development of functional foods or nutraceuticals for the prevention and management of certain diseases.

Arbuscular Mycorrhizal Fungi Modulate the Crop Performance and Metabolic Profile of Saffron in Soilless Cultivation

Saffron (Crocus sativus L.) is cultivated worldwide. Its stigmas represent the highest-priced spice and contain bioactive compounds beneficial for human health. Saffron cultivation commonly occurs in open field, and spice yield can vary greatly, from 0.15 to 1.5 g m−2, based on several agronomic and climatic factors. In this study, we evaluated saffron cultivation in soilless systems, where plants can benefit from a wealth of nutrients without competition with pathogens or stresses related to nutrient-soil interaction. In addition, as plant nutrient and water uptake can be enhanced by the symbiosis with arbuscular mycorrhizal fungi (AMF), we also tested two inocula: a single species (Rhizophagus intraradices) or a mixture of R. intraradices and Funneliformis mosseae. After one cultivation cycle, we evaluated the spice yield, quality (ISO category), antioxidant activity, and bioactive compound contents of saffron produced in soilless systems and the effect of the applied AMF inocula. Spice yield in soilless systems (0.55 g m−2) was on average with that produced in open field, while presented a superior content of several health-promoting compounds, such as polyphenols, anthocyanins, vitamin C, and elevated antioxidant activity. The AMF symbiosis with saffron roots was verified by light and transmission electron microscopy. Inoculated corms showed larger replacement corms (+50% ca.). Corms inoculated with R. intraradices performed better than those inoculated with the mix in terms of spice quality (+90% ca.) and antioxidant activity (+88% ca.). Conversely, the mixture of R. intraradices and F. mosseae increased the polyphenol content (+343% ca.). Thus, soilless systems appeared as an effective alternative cultivation strategy for the production of high quality saffron. Further benefits can be obtained by the application of targeted AMF-based biostimulants.

Enhancement in the Catalytic Activity of Human Salivary Aldehyde Dehydrogenase by Alliin from Garlic: Implications in Aldehyde Toxicity and Oral Health

BACKGROUND

Lower human salivary aldehyde dehydrogenase (hsALDH) activity increases the risk of aldehyde mediated pathogenesis including oral cancer. Alliin, the bioactive compound of garlic, exhibits many beneficial health effects.

OBJECTIVE

To study the effect of alliin on hsALDH activity.

METHODS

Enzyme kinetics was performed to study the effect of alliin on the activity of hsALDH. Different biophysical techniques were employed for structural and binding studies. Docking analysis was done to predict the binding region and the type of binding forces.

RESULTS

Alliin enhanced the dehydrogenase activity of the enzyme. It slightly reduced the Km and significantly enhanced the Vmax value. At 1 µM alliin concentration, the initial reaction rate increased by about two times. Further, it enhanced the hsALDH esterase activity. Biophysical studies indicated a strong complex formation between the enzyme and alliin (binding constant, Kb: 2.35 ± 0.14 x 103 M-1). It changes the secondary structure of hsALDH. Molecular docking study indicated that alliin interacts to the enzyme near the substrate binding region involving some active site residues that are evolutionary conserved. There was a slight increase in the nucleophilicity of active site cysteine in the presence of alliin. Ligand efficiency metrics values indicate that alliin is an efficient ligand for the enzyme.

CONCLUSION

Alliin activates the catalytic activity of the enzyme. Hence, consumption of alliincontaining garlic preparations or alliin supplements and use of alliin in pure form may lower aldehyde related pathogenesis including oral carcinogenesis.

Synergistic Effects of Plant Derivatives and Conventional Chemotherapeutic Agents: An Update on the Cancer Perspective

Synergy is a process in which some substances cooperate to reach a combined effect that is greater than the sum of their separate effects. It can be considered a natural "straight" strategy which has evolved by nature to obtain more efficacy at low cost. In this regard, synergistic effects may be observed in the interaction between herbal products and conventional drugs or biochemical compounds. It is important to identify and exploit these interactions since any improvement brought by such kind of process can be advantageously used to treat human disorders. Even in a complex disease such as cancer, positive synergistic plant-drug interactions should be investigated to achieve the best outcomes, including providing a greater benefit to patients or avoiding adverse side effects. This review analyzes and summarizes the current knowledge on the synergistic effects of plant-drug interactions with a focus on anticancer strategies.

Magnesium taurate attenuates progression of hypertension and cardiotoxicity against cadmium chloride-induced hypertensive albino rats

The present study was designed to evaluate the antihypertensive activity and cardioprotective effects of magnesium taurate against cadmium chloride (CdCl₂)-intoxicated albino rats. Sprague Dawley male albino rats (120-150 g) were divided into five groups having six animals in each group. Hypertension and cardiotoxicity were induced in animals by administration of CdCl₂ (0.5 mg/kg/day, i.p.) for four weeks. Magnesium taurate (2 and 4 mg/kg/day) was administered orally after induction of hypertension (after two weeks) in their respective groups concurrently with CdCl₂ for next two weeks. Amlodipine (3 mg/kg/day, p.o.) was used as a standard and administered after induction of hypertension. Blood pressure was monitored biweekly by using non-invasive blood pressure system and biochemical parameters and histopathology of the heart were evaluated after four weeks of the experimental protocol. During the four weeks of the experimental protocol, the toxic control group showed significant elevation of systolic and diastolic blood pressure concomitant with augmentation of cardiotoxicity as indicated by reduction in myocardial antioxidants including glutathione peroxidase, catalase, superoxide dismutase, reduced glutathione and increased malondialdehyde level in heart as compared to the normal group. The oral administrations of magnesium taurate significantly restored the blood pressure, myocardial antioxidants and malondialdehyde level as compared to toxic control group. In addition, histopathological examination showed that magnesium taurate treatments substantially reduced the myocardial damages against CdCl₂ treatment. The results suggest that magnesium taurate has prominent antihypertensive and cardioprotective activity via its potent antioxidant activity and can be used as a nutrition supplement to improve the cardiovascular health.

Garlic extract attenuates immobilization stress-induced alterations in plasma antioxidant/oxidant parameters and hepatic function in rats

OBJECTIVE

To investigate the oxidative stress induced by 6 h of immobilization stress in Albino Wistar rats. Further, the pre- and post-treatment of aqueous garlic extract was studied to evaluate its preventive and curative efficacy on stress-induced altered oxidative parameters in rats.

METHODS

Albino Wistar rats were exposed to 6 h of immobilization stress, and received garlic extract (100 mg/kg body weight) treatment pre- or post-stress exposure. The oxidative status of plasma after various treatments were evaluated by determining the levels of reduced glutathione, glucose, uric acid, thiobarbituric acid reactive substances, aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and the activities of superoxide dismutase, catalase and glutathione-S-transferase by standardized procedures.

RESULTS

Immobilization of rats generated oxidative stress in rat plasma, by decreasing the activities of antioxidant enzymes, glutathione levels and glucose, while increasing the lipid peroxidation, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, ALP and uric acid compared to the non-stressed controls (P<0.01). The garlic extract administration both pre- and post-stress exposure significantly prevented the rise in the diagnostic liver enzymes and reverted the decrease of antioxidant enzymatic activities compared to the stressed group (P<0.05 or P <0.01). Post-stress treatment of extract was found more effective than pre-stress treatment in reverting the values back to normal (P<0.01).

CONCLUSION

Garlic extract seems promising as a nutritional supplement for scavenging free radicals generated in the plasma and to prevent resulting oxidative stress.

Hypertension potentiates cataractogenesis in rat eye through modulation of oxidative stress and electrolyte homeostasis

Purpose

To evaluate modes of cataractogenesis in the hypertensive state by using different hypertensive animal models, including fructose, cadmium chloride (CdCl₂), N_ω-nitro-l-arginine methyl ester (l-NAME), and two-kidney, one clip (2K1C) method.

Methods

Male Sprague–Dawley albino rats (150–180 g) were divided into different groups, each group containing six animals. Hypertension was induced in animals via six weeks administration of fructose (10% solution in drinking water), CdCl₂ (0.5 mg/kg/day, i.p.), and l-NAME (20 mg/kg/day, p.o.) in their respective groups and NaCl (0.9% solution in drinking water) in the 2K1C group. The Ramipril-treated group (2 mg/kg/day, orally) served as a standard group for the 2K1C animal model. Blood pressure was measured biweekly using non-invasive blood pressure system. The biochemical parameters in serum and eye lenses were evaluated after six weeks of the experimental protocol.

Results

Hypertensive animal models showed significant induction of systolic and diastolic blood pressure and modulation of oxidative stress through depletion of antioxidants, including glutathione peroxidase, catalase, superoxide dismutase, glutathione, and elevation of malondialdehyde in serum and eye lenses. A significant elevation of ionic contents (Na⁺ and Ca²⁺) and reduction of total protein and Ca²⁺ ATPase activity in eye lenses were observed in all hypertensive animal models except l-NAME when compared with the normal group. The significant restoration of the antioxidants, Malondialdehyde (MDA) total protein, and ionic contents in the eye lenses concomitant with reduction of blood pressure were observed in the ramipril-treated group as compared to the 2K1C animal model. The results indicate that the fructose, CdCl_2, and 2K1C models showed pronounced cataractogenic effects in the rat eye lenses.

Conclusion

Based on our findings, it can be concluded that systemic hypertension significantly increases the risk of cataract formation in the rat eyes via modulation of the antioxidant defense mechanism and electrolyte homeostasis.

Effect of captopril and telmisartan on methotrexate-induced hepatotoxicity in rats: impact of oxidative stress, inflammation and apoptosis

Methotrexate (MTX) is a commonly used antineoplastic and anti-rheumatoid drug whose efficacy is limited by its hepatotoxicity. The aim of this study was to investigate the possible protective role of captopril (100 mg/kg/day, p.o. for seven days), an angiotensin converting enzyme inhibitor, and telmisartan (10 mg/kg/day p.o. for seven days), an angiotensin II receptor blocker with peroxisome proliferative receptor gamma (PPARγ) agonism, in a model of MTX (single dose 20 mg/kg i.p. at the fifth day) induced hepatotoxicity in rats. Results of the present study revealed MTX-induced hepatotoxicity as demonstrated by increased level of liver enzymes and confirmed by histopathology. Pretreatment with captopril or telmisartan produced a significant hepatic protection manifested as a significant (p < 0.05) decrease in serum levels of alanine transferase (ALT) and aspartate transferase (AST) and alkaline phosphatase (ALP) enzymes; hepatic malondialdehyde (MDA) and total nitrites and nitrates (NOx) levels; as well as a significant increase in hepatic superoxide dismutase (SOD) activity. In addition, there was a remarkable improvement in the histopathological features and a significant reduction in the expression of COX-2, iNOS and caspase-3 enzymes as compared with the MTX group. We recommend considering captopril/Telmisartan, if tolerated and not contraindicated, as preferable antihypertensive agents in patients receiving MTX in their chemotherapy protocols.

A review on the effects of Allium sativum (Garlic) in metabolic syndrome

The metabolic syndrome is a common problem world-wide and includes abdominal obesity, hypertension, dyslipidemia, and hyperglycemia disorders. It leads to insulin resistance and the development of diabetes mellitus or cardiovascular disease. Allium sativum (garlic) has been documented to exhibit anti-diabetic, hypotensive, and hypolipidemic properties. This suggests a potential role of A. sativum in the management of metabolic syndrome; however, more studies should be conducted to evaluate its effectiveness. In this review, we discussed the most relevant articles to find out the role of A. sativum in different components of metabolic syndrome and cardiovascular disease risk factors. Because human reports are rare, further studies are required to establish the clinical value of A. sativum in metabolic syndrome.

Garlic for hypertension: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

In the past decade, garlic has become one of the most popular complementary therapies for blood pressure (BP) control used by hypertensive patients. Numerous clinical studies have focused on the BP-lowering effect of garlic, but results have been inconsistent. Overall, there is a dearth of information available to guide the clinical community on the efficacy of garlic in hypertensive patients.

AIM

To systematically review the medical literature to investigate the current evidence of garlic for the treatment of hypertension.

METHODS

PubMed, the Cochrane Library and EMBASE were searched for appropriate articles from their respective inceptions until August 2014. Randomized, placebo-controlled trials comparing garlic vs. a placebo in patients with hypertension were considered. Papers were independently reviewed by two reviewers and were analyzed using Cochrane software Revman 5.2.

RESULTS

A total of seven randomized, placebo-controlled trials were identified. Compared with the placebo, this meta-analysis revealed a significant lowering effect of garlic on both systolic BP (WMD: -6.71 mmHg; 95% CI: -12.44 to -0.99; P = 0.02) and diastolic BP (WMD: -4.79 mmHg; 95% CI: -6.60 to -2.99; P < 0.00001). No serious adverse events were reported in any of the trials.

CONCLUSION

The present review suggests that garlic is an effective and safe approach for hypertension. However, more rigorously designed randomized controlled trials focusing on primary endpoints with long-term follow-up are still warranted before garlic can be recommended to treat hypertensive patients.

Pharmacogenomics and herb-drug interactions: merge of future and tradition

The worldwide using of herb products and the increasing potential herb-drug interaction issue has raised enthusiasm on discovering the underlying mechanisms. Previous review indicated that the interactions may be mediated by metabolism enzymes and transporters in pharmacokinetic pathways. On the other hand, an increasing number of studies found that genetic variations showed some influence on herb-drug interaction effects whereas these genetic factors did not draw much attention in history. We highlight that pharmacogenomics may involve the pharmacokinetic or pharmacodynamic pathways to affect herb-drug interaction. We are here to make an updated review focused on some common herb-drug interactions in association with genetic variations, with the aim to help safe use of herbal medicines in different individuals in the clinic.

Pretreatment of garlic powder using sweep frequency ultrasound and single frequency countercurrent ultrasound: optimization and comparison for ACE inhibitory activities

The sweep frequency ultrasound (SFU) and single frequency countercurrent ultrasound (SFCU) pretreatments were modeled and compared based on production of angiotensin I-converting enzyme (ACE) inhibitory peptides from garlic hydrolysates. Two mathematical models were developed to show the effect of each variable and their combinatorial interactions on ACE inhibitory activity. The optimum levels of the parameters in SFU were determined using uniform design, which revealed these as follows: total ultrasonic time 1.5 h, on-time of pulse 18 s and off-time of pulse 3 s. Under optimized conditions, the experimental values of SFU and SFCU were 65.88% and 67.78%, which agreed closely with the predicted values of 63.44% and 67.33%. The SFU and SFCU pretreatments both resulted in higher ACE inhibitory activity compared with untreated garlic (p<0.05). However, there were no significant differences in the ACE inhibitory activities and IC₅₀ values obtained from SFCU and SFU pretreatments under optimum conditions (p>0.05).

Chemical and biochemical mechanisms underlying the cardioprotective roles of dietary organopolysulfides

Foods that are rich in organosulfides are highly regarded for their broad range of functions in disease prevention and health promotion since ancient time yet modern scientific study, particularly clinical studies could not agree with traditional wisdom. One of the complexities is due to the labile nature of organosulfides, which are often transformed to different structures depending on the processing conditions. The recent evidence on polysulfides as H₂S donors may open up a new avenue for establishing structure and health promotion activity relationship. To put this development into perspective, we carried out a review on the recent progress on the chemistry and biochemistry of organopolysulfides with emphasis on their cardioprotective property. First, we briefly surveyed the foods that are rich in polysulfides and their structural diversity. This is followed by in-depth discussion on the chemical transformations of polysulfides under various processing conditions. We further reviewed the potential action mechanisms of polysulfides in cardioprotection through: (a) hydrogen sulfide releasing activity; (b) radical scavenging activity; and (c) activity in enzyme inhibition and intervention of gene regulation pathways. Based on the literature trend, we can conclude that the emerging concept of organopolysulfides as naturally occurring H₂S donors is intriguing and warrants further research to establish the structure and activity relationship of the organopolysulfides as H₂S donors.

Cystathionine gamma-lyase of perivascular adipose tissue with reversed regulatory effect in diabetic rat artery

The aim of this study is to reveal the regulatory role of cystathionine gamma-lyase (CSE), the main source of hydrogen sulphide (H₂S) in perivascular adipose tissue (PVAT), of diabetic rats. Diabetes was induced in male rats by a single intraperitoneal injection of streptozotocin. Animals with glucose levels above 20 mmol/L were determined as diabetic. The rat gracilis arteries (a. gracilis) were dissected with or without PVAT. In all in vitro experiments endothelium-denuded preparations were used for isometric contraction measurements. Increasing concentrations of 5-hydroxytryptamine (5-HT) from 10⁻¹⁰ to 10⁻⁵ mol/L were applied to induce gradual increase in force of contractions of circular artery segments. The relaxing effect of CSE was inhibited by DL-propargyl glycine (PGG). The presence of PVAT decreases the contractile response to 5-HT of a. gracilis from control rats. This response is reversed in contraction studies in the same rat artery from diabetic rats. DL-PPG (1 mmol/L) induced significant increase of the force of contraction in artery preparations with PVAT from control rats in the whole range of 5-HT. In contrast, PGG had a relaxing effect in high concentrations of 5-HT (10⁻⁶ and 10⁻⁵ mol/L) in diabetic rat arteries with PVAT. It is concluded that in skeletal muscle artery from diabetic rats, a mediator related to H₂S is released from PVAT. This paracrine mediator increases the maximal force of contraction of endothelium-denuded preparations at higher concentrations of 5-HT.

Mechanisms underlying the antihypertensive effects of garlic bioactives

Cardiovascular disease remains the leading cause of death worldwide with hypertension being a major contributing factor to cardiovascular disease-associated mortality. On a population level, non-pharmacological approaches, such as alternative/complementary medicine, including phytochemicals, have the potential to ameliorate cardiovascular risk factors, including high blood pressure. Several epidemiological studies suggest an antihypertensive effect of garlic (Allium sativum) and of many its bioactive components. The aim of this review is to present an in-depth discussion regarding the molecular, biochemical and cellular rationale underlying the antihypertensive properties of garlic and its bioactive constituents with a primary focus on S-allyl cysteine and allicin. Key studies, largely from PubMed, were selected and screened to develop a comprehensive understanding of the specific role of garlic and its bioactive constituents in the management of hypertension. We also reviewed recent advances focusing on the role of garlic bioactives, S-allyl cysteine and allicin, in modulating various parameters implicated in the pathogenesis of hypertension. These parameters include oxidative stress, nitric oxide bioavailability, hydrogen sulfide production, angiotensin converting enzyme activity, expression of nuclear factor-κB and the proliferation of vascular smooth muscle cells. This review suggests that garlic and garlic derived bioactives have significant medicinal properties with the potential for ameliorating hypertension and associated morbidity; however, further clinical and epidemiological studies are required to determine completely the specific physiological and biochemical mechanisms involved in disease prevention and management.