Garlic increases antioxidant levels in diabetic and hypertensive rats determined by a modified peroxidase method

Advances in the study of vascular related protective effect of garlic (Allium sativum) extract and compounds

Garlic (Allium sativum) is a functional food containing multiple bioactive compounds that find widespread applications in culinary and medicinal practices. It consists of multiple chemical components, including allicin and alliin. This article offers a comprehensive review of the protective effects of garlic extracts and their active constituents on the vascular system. In vitro and in vivo experiments have shown that garlic extracts and their active ingredients possess various bioactive properties. These substances demonstrate beneficial effects on blood vessels by demonstrating anti-inflammatory and antioxidant activities, inhibiting lipid accumulation and migration, preventing lipid peroxidation, promoting angiogenesis, reducing platelet aggregation, enhancing endothelial function, and inhibiting endothelial cell apoptosis. In clinical studies, garlic and its extracts have demonstrated their efficacy in managing vascular system diseases, including atherosclerosis, diabetes, and high cholesterol levels. In summary, these studies highlight the potential therapeutic roles and underlying mechanisms of garlic and its constituents in managing conditions like diabetes, atherosclerosis, ischemic diseases, and other vascular disorders.

Immunomodulatory and antioxidant effect of green synthesized titanium dioxide nanoparticles on pregnant female albino rats and their fetuses

Titanium dioxide nanoparticles (TiO2 NPs) are one of the various nanoparticles that have been increasingly commonly used in vital sectors. This study was aimed at evaluating the effects of prenatal exposure to the chemical TiO2 NPs (CHTiO2 NPs) and green-synthesized TiO2 NPs (GTiO2 NPs) on immunological and oxidative status as well as lungs and spleen. Fifty pregnant female albino rats were divided into five groups of ten rats each: control, CHTiO2 NPs-treated groups orally received 100 and 300 mg/kg CHTiO2 NPs, and GTiO2 NPs-treated groups received 100 and 300 mg/kg GTiO2 NPs, respectively, daily for 14 days. The serum level of proinflammatory cytokines IL-6, oxidative stress markers (MDA and NO), and antioxidant biomarkers (SOD and GSH-PX) were assayed. Spleen and lungs were collected from pregnant rats and fetuses for histopathological examinations. The results showed a significant increase in IL-6 levels in treated groups. In the CHTiO2 NPs-treated groups, there was a significant increase in MDA activity and a significant decrease in GSH-Px and SOD activities, revealing its oxidative effect, while GSH-Px and SOD activities significantly increased in the 300 GTiO2 NPs-treated group, confirming the antioxidant effect of green-synthesized TiO2 NPs. Histopathological findings of the spleen and lungs of the CHTiO2 NPs-treated group revealed severe congestion and thickening of the blood vessels, while those of the GTiO2 NPs-treated group revealed mild tissue alterations. It could be deduced that green synthesized titanium dioxide nanoparticles have immunomodulatory and antioxidant effects on pregnant female albino rats and their fetuses, with an ameliorated impact on the spleen and lung compared to chemical titanium dioxide nanoparticles.

Garlic (Allium sativum L.) in diabetes and its complications: Recent advances in mechanisms of action

Diabetes mellitus (DM) is a metabolic disease characterized by chronic hyperglycemia and impaired islet secretion that places a heavy burden on the global health care system due to its high incidence rate, long disease course and many complications. Fortunately, garlic (Allium sativum L.), a well-known medicinal plant and functional food without the toxicity and side effects of conventional drugs, has shown positive effects in the treatment of diabetes and its complications. With interdisciplinary development and in-depth exploration, we offer a clear and comprehensive summary of the research from the past ten years, focusing on the mechanisms and development processes of garlic in the treatment of diabetes and its complications, aiming to provide a new perspective for the treatment of diabetes and promote the efficient development of this field.

Onion anthocyanins: Extraction, stability, bioavailability, dietary effect, and health implications

Anthocyanins are high-value compounds, and their use as functional foods and their natural colorant have potential health benefits. Anthocyanins seem to possess antioxidant properties, which help prevent neuronal diseases and thereby exhibit anti-inflammatory, chemotherapeutic, cardioprotective, hepatoprotective, and neuroprotective activities. They also show different therapeutic effects against various chronic diseases. Anthocyanins are present in high concentrations in onion. In recent years, although both conventional and improved methods have been used for extraction of anthocyanins, nowadays, improved methods are of great importance because of their higher yield and stability of anthocyanins. In this review, we compile anthocyanins and their derivatives found in onion and the factors affecting their stability. We also analyze different extraction techniques of anthocyanins. From this point of view, it is very important to be precisely aware of the impact that each parameter has on the stability and subsequently potentiate its bioavailability or beneficial health effects. We present up-to-date information on bioavailability, dietary effects, and health implications of anthocyanins such as antioxidant, antidiabetic, anticancerous, antiobesity, cardioprotective, and hepatoprotective activities.

Current studies and potential future research directions on biological effects and related mechanisms of allicin

Allicin, a thiosulfonate extract from freshly minced garlic, has been reported to have various biological effects on different organs and systems of animals and human. It can reduce oxidative stress, inhibit inflammatory response, resist pathogen infection and regulate intestinal flora. In addition, dozens of studies also demonstrated allicin could reduce blood glucose level, protect cardiovascular system and nervous system, and fight against cancers. Allicin was widely used in disease prevention and health care. However, more investigations on human cohort study are needed to verify the biological or clinical effects of allicin in the future. In this review, we summarized the biological effects of allicin from previous outstanding and valuable studies and provided useful information for future studies on the health effects of allicin.

Effects of Nigella sativa, Camellia sinensis, and Allium sativum as Food Additives on Metabolic Disorders, a Literature Review

Objective: Metabolic disorders (MD) can disturb intracellular metabolic processes. A metabolic disorder can be resulted from enzyme deficits or disturbances in function of various organs including the liver, kidneys, pancreas, cardiovascular system, and endocrine system. Some herbs were used traditionally for spices, food additives, dietary, and medicinal purposes. Medicinal plants possess biological active compounds that enhance human health. We aimed to provide evidence about therapeutic effects of some medicinal herbs on MD.

Data Sources: PubMed, Scopus, and Google Scholar were explored for publications linked to MD until February 2021. The most literature reports that were published in the last 10 years were used. All types of studies such as animal studies, clinical trials, and in vitro studies were included. The keywords included “Metabolic disorders,” “Nigella sativa L.,” “Thymoquinone,” “White tea”OR “Camellia sinensis L.” “catechin,” and “Allium sativum L.” OR “garlic” were searched.

Results: Based on the results of scientific studies, the considered medicinal plants and their active components in this review have been able to exert the beneficial therapeutic effects on obesity, diabetes mellitus and non-alcoholic fatty liver disease.

Conclusions: These effects are obvious by inhibition of lipid peroxidation, suppression of inflammatory reactions, adjustment of lipid profile, reduction of adipogenesis and regulation of blood glucose level.

Diallyl Trisulfide, the Antifungal Component of Garlic Essential Oil and the Bioactivity of Its Nanoemulsions Formed by Spontaneous Emulsification

The aim of this study was to evaluate the chemical compounds of garlic essential oil (EO), and determine the antifungal efficacy of garlic EO and its major components, diallyl trisulfide and its nanoemulsions against wood-rotting fungi, Trametes hirsuta and Laetiporus sulphureus. GC-MS analysis revealed that the major constituents of garlic EO were diallyl trisulfide (39.79%), diallyl disulfide (32.91%), and diallyl sulfide (7.02%). In antifungal activity, the IC₅₀ value of garlic EO against T. hirsuta and L. sulphureus were 137.3 and 44.6 μg/mL, respectively. Results from the antifungal tests demonstrated that the three major constituents were shown to have good antifungal activity, in which, diallyl trisulfide was the most effective against T. hirsuta and L. sulphureus, with the IC₅₀ values of 56.1 and 31.6 μg/mL, respectively. The diallyl trisulfide nanoemulsions showed high antifungal efficacy against the examined wood-rotting fungi, and as the amount of diallyl trisulfide in the lipid phase increases, the antifungal efficacy of the nanoemulsions increases. These results showed that the nanoemulsions and normal emulsion of diallyl trisulfide have potential to develop into a natural wood preservative.

Impacts of garlic extract on testicular oxidative stress and sperm characteristics in type 1 and 2 diabetic rats: An experimental study

BACKGROUND

Hyperglycemia damages various tissues such as the testes through oxidative stress and inflammation, which can eventually lead to infertility.

OBJECTIVE

Garlic extract effects on the testicular tissue of diabetic rats were investigated.

MATERIALS AND METHODS

In this experimental study, 36 male Wistar rats (8-wk old, weighing 230-300 gr) were randomly divided into 6 groups (n = 6/each) including; C: control rats, G: received 0.4 gr of garlic extract/100 gr body weight, D1: Streptozotocin-induced-diabetic rats or type 1, D1+G: D1 rats that were treated with garlic, D2: Streptozotocin + nicotinamide-induced-diabetic rats or type 2, D2+G: D2 rats treated with garlic. At the end of the study, serum testosterone was assayed by ELISA. Also, sperm quality and quantity were evaluated. For determination of oxidative stress status, total antioxidant capacity, total oxidative status, lipid peroxidation, and thiol groups were assayed in the testis tissues of the rats by colorimetric methods. Also, inducible nitric oxide synthase (iNOS) gene expression and the protein level of interleukin-1 β (IL-1 β ) were determined by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively.

RESULTS

In diabetic rats, glucose, total oxidative status and lipid peroxidation, iNOS gene expression, and IL-1 β were higher than in non-diabetic rats, whereas testosterone, total antioxidant capacity and thiol groups, and sperm quality were significantly lower compared with control rats. These alterations were normalized by garlic intervention.

CONCLUSION

In diabetic rats, garlic was associated with reduced glucose, oxidative stress, IL-1 β , and iNOS gene expression and increased testosterone and sperm quality. So, the results suggest that garlic can reduce the severity of damage in testicular tissues of diabetic rats through its hypoglycemic, antioxidant, and anti-inflammatory properties.

The effect of garlic (Allium sativum) supplementation on the lipid parameters and blood pressure levels in women with polycystic ovary syndrome: A randomized controlled trial

Polycystic ovary syndrome (PCOS) is the most prevalent female endocrine-related disorder in reproductive ages. The aim of the study was to investigate the effect of garlic on the lipid parameters and blood pressure levels in women with PCOS. The present study was a randomized, double-blinded control trial, conducted on 80 PCOS patients. Participants were taught to intake either a total 800 mg/day garlic supplement or an identical placebo (starch) after lunch for 8 weeks. Physical activity, diet intake, anthropometric measures, and blood pressure were evaluated at baseline and end of the study. The blood sample was also taken to assess the change in outcomes of interest at the pre- and post-intervention. Garlic supplementation significantly reduced serum total cholesterol (change mean difference: -8.05, 95% CI: -15.47, -0.62) and LDL-C (change mean difference: -7.67, 95%CI: -14.64, -0.70) levels in comparison to the control group. In addition, a trend to a significant decrease was found in serum triglyceride levels and Systolic blood pressure; however, no significant difference was observed between two groups in HDL-C and diastolic blood pressure levels. The present study suggested that garlic supplementation might be effective on lipid markers improvement. Further studies are needed to confirm our findings.

The Anxiolytic and Antidepressant Effects of Diallyl Disulfide and GYY4137 in Animals with Chronic Neuropathic Pain

When neuropathic pain is maintained long term, it can also lead to the development of emotional disorders that are even more intense than pain perception and difficult to treat. Hydrogen sulfide (H₂S) donors relieve chronic pain, but their effects on the associated mood disorders are not completely elucidated. We evaluated if treatment with DADS (diallyl disulfide) or GYY4137 (morpholin-4-ium 4-methoxyphenyl(morpholino) phosphinodithioate dichloromethane complex), two slow-releasing H₂S donors, inhibits the anxiety- and depressive-like behaviors that concur with chronic neuropathic pain generated by sciatic nerve injury in mice. The modulatory role of these drugs in the inflammatory, apoptotic, and oxidative processes implicated in the development of the affective disorders was assessed. Our results revealed the anxiolytic, antidepressant, and antinociceptive properties of DADS and GYY4137 during neuropathic pain by inhibiting microglial activation and the up-regulation of phosphoinositide 3-kinase/phosphorylated protein kinase B and BAX in the amygdala (AMG) and/or periaqueductal gray matter (PAG). Both treatments also normalized and/or activated the endogenous antioxidant system, but only DADS blocked ERK 1/2 phosphorylation. Both H₂S donors decreased allodynia and hyperalgesia in a dose-dependent manner by activating the Kv7 potassium channels and heme oxygenase 1 signaling pathways. This study provides evidence of the anxiolytic and antidepressant properties of DADS and GYY4137 during neuropathic pain and reveals their analgesic actions, suggesting that these therapeutic properties may result from the inhibition of the inflammatory, apoptotic, and oxidative responses in the AMG and/or PAG. These findings support the use of these treatments for the management of affective disorders accompanying chronic neuropathic pain.

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.

Garlic (Allium sativum) improves anxiety- and depressive-related behaviors and brain oxidative stress in diabetic rats

This study investigated the effects of garlic on anxiety- and depression-related behaviors and brain oxidative markers in streptozotocin (STZ)-induced diabetes in rats. Fifty-six male Wistar rats were randomly divided into seven experimental groups (n = 8/group): control, diabetic + saline, diabetic + garlic, diabetic + imipramine, and diabetic + diazepam groups. Animals received garlic homogenate (0.1, 0.25, and 0.5 g/kg) for 10 days. At the end of the treatments, anxiety- and depressive-related behaviors were evaluated by elevated plus maze (EPM) and forced swimming test (FST), respectively. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and malondialdehyde (MDA) levels were measured in the brain. Diabetic + garlic (0.5 g/kg) group showed lower anxiety- and- depressive-like behaviors as compared to the diabetic rats. Furthermore, garlic treatment (0.5 g/kg) attenuated MDA levels and enhanced SOD and GPx activities in the brain. Our findings indicate that garlic alleviates anxiety- and depression-related behaviors in the diabetic rats possibly by attenuation of brain oxidative stress.

Garlic essential oil mediates acute and chronic mild stress-induced depression in rats via modulation of monoaminergic neurotransmission and brain-derived neurotrophic factor levels

Garlic essential oil (GEO) and its major organosulfur component (diallyl disulfide, DADS) possess diverse biological properties; however, limited information on their antidepressant-like effects is available. This study is the first to investigate these effects of GEO using the forced swimming test (FST) and unpredictable chronic mild stress (UCMS) induced depression in rats. After oral administration for 28 consecutive days, GEO (25 and 50 mg per kg bw) significantly reduced the immobility time in the FST. Additionally, GEO and DADS significantly reversed the sucrose preference index decrease induced by 5 weeks of UCMS. GEO (25 mg per kg bw) effectively decreased the frontal cortex turnover ratio of serotonin (5-HT) and dopamine (DA), thus increasing the 5-HT and DA levels, with no hippocampal effects. Chronic GEO treatment increased hippocampal brain-derived neurotrophic factor (BDNF), c-AMP response element binding protein (CREB), and protein kinase B (AKT) expression, exhibiting its effects via monoamine neurotransmitter modulation and the BDNF-related signaling pathway.

Wasef L, Elewa YHA, A. Al-Sagan A, Abd El-Hack ME, Taha AE, M. Abd-Elhakim Y, Prasad Devkota H. Chemical Constituents and Pharmacological Activities of Garlic (Allium sativum L.): A Review

Medicinal plants have been used from ancient times for human healthcare as in the form of traditional medicines, spices, and other food components. Garlic (Allium sativum L.) is an aromatic herbaceous plant that is consumed worldwide as food and traditional remedy for various diseases. It has been reported to possess several biological properties including anticarcinogenic, antioxidant, antidiabetic, renoprotective, anti-atherosclerotic, antibacterial, antifungal, and antihypertensive activities in traditional medicines. A. sativum is rich in several sulfur-containing phytoconstituents such as alliin, allicin, ajoenes, vinyldithiins, and flavonoids such as quercetin. Extracts and isolated compounds of A. sativum have been evaluated for various biological activities including antibacterial, antiviral, antifungal, antiprotozoal, antioxidant, anti-inflammatory, and anticancer activities among others. This review examines the phytochemical composition, pharmacokinetics, and pharmacological activities of A. sativum extracts as well as its main active constituent, allicin.

Medicinal plants with concomitant anti-diabetic and anti-hypertensive effects as potential sources of dual acting therapies against diabetes and hypertension: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetes and hypertension are pathophysiologically related diseases that co-exist with a wider complex of metabolic diseases having similar set of risk factors. There are numerous ethnopharmacological evidences on the anti-diabetic and/or anti-hypertensive properties of medicinal plants from various parts of the world, which are used as therapies to concomitantly manage diabetes and hypertension.

AIM OF THE REVIEW

This article reviewed findings on medicinal plants with both anti-diabetic and anti-hypertensive effects reported in same experimental study to facilitate the development of dual-acting therapies against diabetes and hypertension.

MATERIALS AND METHODS

A literature search was carried out on different scientific search engines including, but not limited to "PubMed", "Google Scholar", "Scopus" and ScienceDirect to identify published data in which plants in same experimental studies were reported to possess both anti-hyperglycemic and anti-hypertensive effects. Subsequently, the anti-diabetic/anti-hypertensive potency ratio (ψ) of the medicinal plants was computed.

RESULTS

Sixty-four studies with 102 plant species matched the selection criteria. Members of the Fabaceae family were the most investigated plants, while the ψ greatly varied across the plants, with only 11 plants having a ψ ≃ 1. Withania somnifera Dunal was the only plant reported to show blood glucose-lowering and diuretic effects in humans, comparable to daonil. Caffeic acid, chlorogenic acid, caftaric acid, cichoric acid, verbascoside, leucosceptoside A, isoacteoside, fucoxanthin and nicotinamide were the reported dual acting anti-diabetic and anti-hypertensive compounds identified and/or isolated in the plants.

CONCLUSIONS

This review suggests that medicinal plants possess varied therapeutic dynamics against hypertension and diabetes that could be exploited for the discovery of therapeutic preparation(s) or agent(s) for treating the two diseases.

Onion (Allium cepa L.) is potentially a good source of important antioxidants

Six different cultivars of onions available in the Kuwaiti market were analyzed for various physic-chemical properties, such as, moisture content, sugar composition, TBARS as malondialdehyde, total phenolic content, as well as trolox equivalent antioxidant capacity, these cultivars comprised of US onions white, US onions yellow, Indian onions red, Egyptian onions red, New Zealand onions golden and Saudi onions white. Layers from each onion bulb were manually cut and separated into three nearly equal portions, i.e., outer layers, middle layers and the inner layers. The outermost layers of the bulb showed the highest concentration of antioxidant compounds and a distinct decreasing trend was observed towards the innermost layers in all types of onion samples. The onion samples studied showed variations in carbohydrate contents (glucose, fructose and sucrose), which would have important implications in affecting the flavor (sweetness and pungency) and the suitability of these onions for processing. An important observation is about the distribution of antioxidant compounds with the highest contents in the outmost layers of the onions than in their middle and inner layers. Unfortunately, these outer layers are generally discarded by the consumers thus depriving them of the important health-promoting phytochemicals.

Hypoglycemic and hypolipidemic effect of S-allyl-cysteine sulfoxide (alliin) in DIO mice

Alliin (S-allyl cysteine sulfoxide) is a bioactive sulfoxide compound derived from garlic. To evaluate the preventive effect of alliin against metabolic risk factors in diet induced obese (DIO) mice, we treated the C57BL/6J DIO mice with drinking water with or without alliin (0.1 mg/ml) for 8 weeks. Results showed that alliin had no significant effect on the body weight, adiposity or energy balance. However, alliin treatment enhanced glucose homeostasis, increased insulin sensitivity and improved the lipid profile in the DIO mice. This was, at least partly, attributable to alliin induced modulation of the intestinal microbiota composition, typically decreased Lachnospiraceae and increased Ruminococcaceae. From above, we conclude that alliin has nutraceutical or even medicinal potential in prevention of diabetes and lipid metabolic disorders.

Natural antioxidants in the treatment and prevention of diabetic nephropathy; a potential approach that warrants clinical trials

Diabetic nephropathy is the major cause of end-stage renal disease and effective and new therapeutic approaches are needed in diabetic nephropathy and chronic kidney diseases. Oxidative stress and inflammatory process are important factors contributing to kidney damage by increasing production of oxidants. KEAP1/Nrf2/ARE pathway regulates the transcription of many antioxidant genes and modulation of the pathway up regulates antioxidants. NFB controls the expression of genes involved in the inflammatory response. Natural substances have antioxidant and anti-inflammatory activities and have an impact on NFB and KEAP1/Nrf2/ARE pathways. The preclinical studies explored the effectiveness of whole herbs, plants or seeds and their active ingredients in established diabetic nephropathy. They ameliorate oxidative stress induced kidney damage, enhance antioxidant system, and decrease inflammatory process and fibrosis; most likely by activating KEAP1/Nrf2/ARE pathway and by deactivating NFB pathway. Whole natural products contain balanced antioxidants that might work synergistically to induce beneficial therapeutic outcome. In this context, more clinical studies involving whole plants or herbal products or mixtures of different herbs and plants and their active ingredients might change our strategies for the management of diabetic nephropathy. The natural products might be useful as preventive interventions and studies are required in this field.

Garlic Attenuates Plasma and Kidney ACE-1 and AngII Modulations in Early Streptozotocin-Induced Diabetic Rats: Renal Clearance and Blood Pressure Implications

Raw garlic aqueous extract (GE) has ameliorative actions on the renin-angiotensin system in type-1 diabetes mellitus (DM); however its effects on plasma and kidney angiotensin I converting enzyme type-1 (ACE-1) and angiotensin II (AngII) require further elucidation. This study investigated the effect of GE on plasma and kidney ACE-1 and AngII concentrations and in relation to systemic and renal clearance indicators significant to blood pressure (BP) homeostasis in early streptozotocin- (STZ-) induced type-1 DM. Normal rats (n = 10) received 0.5 mL normal saline (NR/NS), diabetic rats (n = 10) received 0.5 mL NS (DR/NS), and treated diabetic rats (n = 10) received 50 mg/0.1 mL/100 g body weight GE (DR/GE) as daily intraperitoneal injections for 8 weeks. Compared to NR/NS, DR/NS showed a significant increase in plasma ACE-1 and AngII and conversely a decrease in kidney ACE-1 and AngII. These changes were associated with an increase in BP and clearance functions. Alternatively and compared to DR/NS, DR/GE showed normalization or attenuation in plasma and kidney ACE-1 and AngII. These GE induced rectifications were associated with moderation in BP elevation and renal clearance functions. Garlic attenuates modulations in plasma and kidney ACE-1 and AngII, in addition to BP and renal clearance function in type-1 DM.

Garlic decreases liver and kidney receptor for advanced glycation end products expression in experimental diabetes

The up-regulation of the receptor for advanced glycation end products (RAGE) has been implicated as a major mediator in the development and progression of diabetic nephropathy and hepatic fibrogenesis. The present study was designed to investigate the potential of garlic (Allium sativum L.) to modulate the level of expression of RAGE in renal and hepatic tissues of diabetic rats. Three groups of rats were studied after 8 weeks following diabetes induction: normal, streptozotocin-induced diabetic (control diabetic), and garlic-treated diabetic rats. A polyclonal antibody of proven specificity to RAGE indicated in immunohistochemical assays that RAGE labeling was significantly increased in renal and hepatic tissues of control diabetic rats compared to the normal group. The increased RAGE labeling involved mesangial cells in glomeruli exhibiting signs of mesangial expansion, mesangial nodule formation and glomerulosclerosis. In the liver, a significant up-regulation of RAGE was observed in hepatocytes and bile ducts and vessels in portal tracts. In 2-dimensional Western blots, RAGE expression in both tissues was dominated by heterogeneous charge variants, represented by 46-50kDa isoforms with more basic pIs compared to their counterparts in normal rats. Compared to control diabetic rats, RAGE labeling in the garlic-treated diabetic group was significantly reduced throughout renal and hepatic regions and was marked by the expression of 43-50kDa acidic charge variants comparable to those observed in normal rats. The capacity of garlic to modulate diabetes-induced up-regulation of selective RAGE polymorphic variants may be implicated in attenuating the detrimental consequences of excessive RAGE signaling manifested by diabetes-associated disorders.

Anti-diabetic and anti-oxidant potential of aged garlic extract (AGE) in streptozotocin-induced diabetic rats

Background

Although aged garlic extract (AGE) shares some active components with fresh garlic and in spite of its palatability and milder side effects, the anti-diabetic and related anti-oxidant properties of AGE have not been investigated extensively, and the reported findings are inconsistent.

This study investigated the anti-diabetic effects of 3 incremental doses of AGE in streptozotocin (STZ)-induced diabetic rats (fasting blood sugar > 20 mM).

Method

Diabetic rats were divided into a control diabetic group (CD) and AGE-treated diabetic group (AGE-D). The AGE-D was divided into 3 groups and accordingly treated with AGE i.p. at 100, 300 and 600 mg/kg daily for 8 weeks. A control normal group (CN) was also included for reference.

Results

Compared to the CN group, the CD group showed significant loss of body weight (over 50 %); and decreased serum insulin concentration (10 fold) and total anti-oxidant level and catalase activity (45–70 %) in serum, kidney and liver. Conversely, the CD rats had an elevated blood glucose (nearly 4 fold), serum cholesterol (nearly 2 fold) and triglycerides (>2 fold), erythrocyte glycated hemoglobin (GHb, 3 fold) and kidney and liver lipid peroxidation (MDA levels). Treatment with AGE positively reversed the diabetic changes in the targeted parameters to levels significantly lower than those measured in the CD group and the degrees of attenuation were almost dose dependent especially with the two higher doses.

Conclusion

AGE exhibits a dose-dependent ameliorative action on indicators of diabetes in STZ-induced diabetic rats.

Anti-hypertensive Herbs and their Mechanisms of Action: Part I

The use of herbal therapies for treatment and management of cardiovascular diseases (CVDs) is increasing. Plants contain a bounty of phytochemicals that have proven to be protective by reducing the risk of various ailments and diseases. Indeed, accumulating literature provides the scientific evidence and hence reason d'etre for the application of herbal therapy in relation to CVDs. Slowly, but absolutely, herbal remedies are being entrenched into evidence-based medical practice. This is partly due to the supporting clinical trials and epidemiological studies. The rationale for this expanding interest and use of plant based treatments being that a significant proportion of hypertensive patients do not respond to Modern therapeutic medication. Other elements to this equation are the cost of medication, side-effects, accessibility, and availability of drugs. Therefore, we believe it is pertinent to review the literature on the beneficial effects of herbs and their isolated compounds as medication for treatment of hypertension, a prevalent risk factor for CVDs. Our search utilized the PubMed and ScienceDirect databases, and the criterion for inclusion was based on the following keywords and phrases: hypertension, high blood pressure, herbal medicine, complementary and alternative medicine (CAM), nitric oxide, vascular smooth muscle cell (VSMC) proliferation, hydrogen sulfide, nuclear factor kappa-B, oxidative stress, and epigenetics/epigenomics. Each of the aforementioned keywords was co-joined with herb in question, and where possible with its constituent molecule(s). In this first of a two-part review, we provide a brief introduction of hypertension, followed by a discussion of the molecular and cellular mechanisms. We then present and discuss the plants that are most commonly used in the treatment and management of hypertension.

Age-dependent alteration of antioxidant defense system in hypertensive and type-2 diabetes patients

BACKGROUND

The association between hypertension and diabetes has been linked to increased oxidative stress with age. This study was to examine the level of age-dependent alterations in antioxidant defense system between patients having hypertension and/or type-2 diabetes.

METHODS

The study was conducted at the Ahmadu Bello University Teaching Hospital, Zaria-Nigeria, using 200 Subjects recruited from the cardiology, endocrinology and outpatient clinics. They were divided into four groups of 50 subjects each, namely: Diabetic group (DG), hypertensive (HG) and hypertensive-diabetic group (HDG) as cases. The control group (CG) was non-diabetic normotensive subjects. They were all stratified into six age-ranges namely 20-29, 30-39, 40-49, 50-59, 60-69, 70-79 years. Oxidative stress markers (lipid peroxidation, antioxidant vitamins and elements, enzymatic and non-enzymatic antioxidant) were measured in the blood sample collected from all subjects in each age group within the study groups.

RESULTS

The results in the DG, HG and HDG, showed that the percentage decrease in enzymatic antioxidants and antioxidant vitamins with age were significantly (P < 0.05) higher than 10.8% and 20.0% respectively when compared to the CG, whereas, the level of decrease in serum Selenium at same age range was significantly higher than 52.8%. The level of lipid peroxidation in the cases was observed to be significantly (P < 0.05) higher than 89.9% when compared to the mean reference values (2.94 ± 0.05 nmol/ml) of the CG at same age range. Also, the decrease levels of endogenous antioxidants were observed to be directly related to aging.

CONCLUSION

The result obtained demonstrates the percentage age-dependent alteration in oxidative stress markers. The percentage decrease in the antioxidant levels during aging could be an explanation to the possible link, underlying the complication of type-2 diabetes and hypertension in this locale. Hence, antioxidants supplements may be useful in the management of the diseases during aging.

Anti-oxidative role of quercetin derived from Allium cepa on aldehyde oxidase (OX-LDL) and hepatocytes apoptosis in streptozotocin-induced diabetic rat

OBJECTIVE

To study the role of Quercetin in streptozotocin-induced diabetes in rats.

METHODS

Wistar male rat (n=40) were allocated into three groups, control group (n=10) and Quercetin (QR) group received 15 mg/kg (IP) QR, (n=10), and diabetic group that received 55 mg/kg (IP) streptozotocin (STZ) (n=20) which was subdivided to two groups of 10; STZ group and treatment group. Treatment group received 55 mg/kg (IP) STZ plus 15 mg/kg QR, daily for 4 weeks, respectively; however, the control group just received an equal volume of distilled water daily (IP). Diabetes was induced by a single (IP) injection of streptozotocin (55 mg/kg). Animals were kept in standard condition. Twenty-eight days after inducing diabetic, 5 mL blood were collected for TAC, MDA and Ox-LDL levels and liver tissues of rat in whole groups were removed then prepared for apoptosis analysis by Tunel method.

RESULTS

Apoptotic cells significantly decreased in group that has received 15 mg/kg (IP) Quercetin (P<0.05) in comparison to experimental groups (P<0.05).

CONCLUSIONS

Since in our study 15 mg/kg (IP) Quercetin have significantly Preventive effect on liver cells damages by reducing number of apoptotic cells in Liver, so it seems that using it can be effective for treatment in diabetic rat.

Ancient records and modern research on the mechanisms of chinese herbal medicines in the treatment of diabetes mellitus

Over the past decades, Chinese herbal medicines (CHM) have been extensively and intensively studied through from both clinical and experimental perspectives and CHM have been proved to be effective in the treatment of diabetes mellitus (DM). This study, by searching ancient records and modern research papers, reviewed CHM in terms of their clinical application and principal mechanism in the treatment of DM. We summarized the use of CHM mentioned in 54 famous ancient materia medica monographs and searched papers on the hypoglycemic effect of several representative CHM. Main mechanisms and limitations of CHM and further research direction for DM were discussed. On the basis of the study, we were led to conclude that TCM, as a main form of complementary and alternative medicine (CAM), was well recorded in ancient literatures and has less adverse effects as shown by modern studies. The mechanisms of CHM treatment of DM are complex, multilink, and multitarget, so we should find main hypoglycemic mechanism through doing research on CHM monomer active constituents. Many CHM monomer constituents possess noteworthy hypoglycemic effects. Therefore, developing a novel natural product for DM and its complications is of much significance. It is strongly significant to pay close attention to CHM for treatment of DM and its complications.

Effect of Cinnamomum zeylanicumon on Spermatogenesis

Background:

In modern countries today, herbal medicines are known to help in the treatment of various diseases, as rich sources of antioxidants and minerals.

Objectives:

To study the effect of Cinnamomum zeylanicum (C. zeylanicum) on spermatogenesis in rats.

Materials and Methods:

In this experimental study, Wistar male rats (n = 20) were divided into two groups, a control group (n = 10) and a Cinnamomum zeylanicum group (n = 10). The subjects in the cinnamon group received 75 mg/kg/day cinnamon by gavage for 28 days, while the controls received an equal volume of distilled water daily. Animals were kept in standardized conditions. On day 28, a 5 mL blood sample from each rat was taken from tail area to measure testosterone, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and malondialdehyde (MDA) levels. Testes were collected and were then prepared for sperm analysis by the WHO method.

Results:

Sperm quality parameters, total serum testosterone, SOD, CAT, and GPX levels were significantly increased in the cinnamon group in comparison to controls (P < 0.05). Also, rats in the cinnamon group showed a significant decrease in the level of plasma MDA (P < 0.05) in comparison to controls. There were no significant differences between the groups in testis weight (P > 0.05).

Conclusions:

The administration of 75 mg/kg/day cinnamon significantly increased the sperm population, motility and viability, which supports the theory that in mammalians, cinnamon has a beneficial effect on spermatogenesis.

Therapeutic uses and pharmacological properties of garlic, shallot, and their biologically active compounds

OBJECTIVE(S)

Garlic (Allium sativum L. family Liliaceae) is well known in Iran and its leaves, flowers, and cloves have been used in traditional medicine for a long time. Research in recent decades has shown widespread pharmacological effects of A. sativum and its organosulfur compounds especially Allicin. Studies carried out on the chemical composition of the plant show that the most important constituents of this plant are organosulfur compounds such as allicin, diallyl disulphide, S-allylcysteine, and diallyl trisulfide. Allicin represents one of the most studied among these naturally occurring compounds. In addition to A. sativum, these compounds are also present in A. hirtifolium (shallot) and have been used to treat various diseases. This article reviews the pharmacological effects and traditional uses of A. sativum, A. hirtifolium, and their active constituents to show whether or not they can be further used as potential natural sources for the development of novel drugs.

MATERIALS AND METHODS

For this purpose, the authors went through a vast number of sources and articles and all needed data was gathered. The findings were reviewed and classified on the basis of relevance to the topic and a summary of all effects were reported as tables.

CONCLUSION

Garlic and shallots are safe and rich sources of biologically active compounds with low toxicity. Further studies are needed to confirm the safety and quality of the plants to be used by clinicians as therapeutic agents.

Traditional Indian medicines used for the management of diabetes mellitus

Plants have always been a source of drugs for humans since time immemorial. The Indian traditional system of medicine is replete with the use of plants for the management of diabetic conditions. According to the World Health Organization, up to 90% of population in developing countries use plants and its products as traditional medicine for primary health care. There are about 800 plants which have been reported to show antidiabetic potential. The present review is aimed at providing in-depth information about the antidiabetic potential and bioactive compounds present in Ficus religiosa, Pterocarpus marsupium, Gymnema sylvestre, Allium sativum, Eugenia jambolana, Momordica charantia, and Trigonella foenum-graecum. The review provides a starting point for future studies aimed at isolation, purification, and characterization of bioactive antidiabetic compounds present in these plants.

Potentiation of antioxidant effect of dietary tender cluster beans (Cyamopsis tetragonoloba) by garlic (Allium sativum) in high-cholesterol-fed rats

The antioxidant role of tender cluster beans (Cyamopsis tetragonoloba, CB), a rich source of soluble fibre, was investigated in a hypercholesterolemia-induced oxidative stress situation in rats. In the context of dietary garlic (Allium sativa) potentiating the hypocholesterolemic influence of CB, we also examined if dietary garlic enhances the antioxidant potential of CB. Groups of Wistar rats were rendered hypercholesterolemic by feeding them a 0.5% cholesterol diet for 8 weeks. Dietary interventions were made by inclusion of 15% tender CB powder or 1% garlic powder or their combination in a high-cholesterol diet. Concentrations of antioxidant molecules and activities of antioxidant enzymes in blood and liver were examined. Dietary CB displayed an antioxidant influence in terms of elevating ascorbic acid and glutathione concentrations and stimulating the activities of antioxidant enzymes both in blood and liver. The antioxidant effect of dietary CB was generally potentiated by co-administration of garlic. Thus, consumption of tender CB and garlic together could form a strategy for improving the body's antioxidant status.

Green Tea Attenuates Oxidative Stress and Downregulates the Expression of Angiotensin II AT(1) Receptor in Renal and Hepatic Tissues of Streptozotocin-Induced Diabetic Rats

This study investigates the potential of green tea to modulate oxidative stress and angiotensin II AT₁ receptor expression in renal and hepatic tissues of diabetic rats. Three groups of rats were studied after 8 weeks following diabetes induction: normal, streptozotocin-induced diabetic (diabetic control), and green-tea-treated diabetic rats. Total antioxidant, catalase, and malondialdehyde levels were assayed by standard procedures. Levels of AT₁ receptor labeling, in renal and hepatic tissues of the three rat groups, were immunohistochemically investigated using an anti-AT₁ receptor antibody. Levels of total antioxidant and catalase were significantly reduced, whereas malondialdehyde levels and AT₁ receptor labeling were significantly increased in renal and hepatic tissues of diabetic control rats compared to normal rats. Compared to diabetic control rats, total antioxidant and catalase levels were significantly increased, whereas malondialdehyde levels and AT₁ receptor labeling in the green-tea-treated diabetic group were significantly reduced throughout hepatic lobules and renal cortical and medullary vascular and tubular segments to levels comparable to those observed in normal rats. The capacity of green tea to modulate diabetes-induced oxidative stress and AT₁ receptor upregulation may be beneficial in opposing the deleterious effects of excessive angiotensin II signaling, manifested by progressive renal and hepatic tissue damage.

Mechanisms of cardioprotective effect of aged garlic extract against Doxorubicin-induced cardiotoxicity

Aged garlic has been extensively studied and has been shown to have a number of medicinal properties, including immunomodulatory, hepatoprotective, antimutagenic, anticarcinogenic, and antioxidant effects. The objective of this study was to investigate the mechanisms of the cardioprotective effect of aged garlic extract (AGE), a widely used herbal medicine with potent antioxidant activity, against doxorubicin-induced cardiotoxicity. Moreover, the study investigated if the cardioprotective effect of AGE might be at the expense of the antitumor effect of the anticancer drug doxorubicin (DOX). Primary cultured neonatal rat cardiac myocytes were treated with DOX, AGE, and their combination for 24 hours. DOX increased p53 and caspase 3 activity-induced apoptotic cell death, whereas AGE pretreatment suppressed the action of DOX. AGE pretreatment did not interfere with the cytotoxic activity of DOX, but it increased the DOX uptake into tumor cells and increased the long term survivors of tumor-bearing mice from 30% to 70%. In conclusion, DOX impairs viability of cardiac myocytes, at least partially by activating the p53-mediated apoptotic signaling. AGE can effectively and extensively counteract this action of DOX and may potentially protect the heart from severe toxicity of DOX. At the same time, AGE did not interfere with antitumor activity of DOX.

Pharmacodynamic and Pharmacokinetic Interactions of Propranolol with Garlic (Allium sativum) in Rats

Garlic preparations and propranolol (PRO) are agents recognized as cardioprotective and potent antihypertensive agents when they are used individually. However, there is no report available to explain the role of combined therapy during simultaneous hypertension and myocardial damage in rats. We aimed to determine the pharmacokinetic and pharmacodynamic interaction of PRO with garlic homogenate (GH), in rats. The influence of garlic on pharmacokinetics of PRO was determined by HPLC method; while pharmacodynamic interaction was studied in animals with hypertension (10% fructose) and myocardial damage (isoproterenol, 175 mg kg(-1), s.c. 2 days). PRO was given orally at 10 mg kg(-1) for 1 week, whereas, GH was administered at three different doses of 125, 250 and 500 mg kg(-1), p.o. in their respective groups during fourth to sixth week of high fructose (HF) period, once daily. Systolic blood pressure (SBP), heart rate, cholesterol, triglycerides, glucose, creatine phosphokinase-MB, lactate dehydrogenase, superoxide dismutase and catalase were measured and histopathological studies were carried out. The bioavailability and half life of PRO were significantly enhanced by 2- and 3-fold, respectively, in animals pretreated with garlic (250 mg kg(-1)). Administration of PRO and low to moderate doses of GH (125, 250 mg kg(-1)), either alone or together showed fall in fluid intake and body weight. The combined therapy of GH 250 mg kg(-1) and PRO was found to be most effective in reducing SBP, cholesterol, triglycerides and glucose. These observations suggest that careful addition of garlic in moderate doses in PRO regimen might result in beneficial effect during treatment of hypertensive animals with myocardial damage.

Free Radical Scavenging, Cytotoxic and Hemolytic Activities from Leaves of Acacia nilotica (L.) Wild. ex. Delile subsp. indica (Benth.) Brenan

Dietary intake of phytochemicals having antioxidant activity is associated with a lower risk of mortality from many diseases. Therefore, the aim of this study was to determine the free radical scavenging, cytotoxic and hemolytic activities of leaves of Acacia nilotica by using various methods. The results of the present study revealed that ethanol extract was the most effective and IC₅₀ value was found to be 53.6 μg mL⁻¹ for Vero cell lines and 28.9 μg mL⁻¹ for Hela cell lines in cytotoxicity assays. The zone of color retention was 14.2 mm in β-carotene bleaching assay, which was as significant as positive control, butylated hydroxy toluene. None of the tested extracts possessed any hemolytic activity against rat and human erythrocytes revealing their cytotoxic mechanism and non-toxicity. Thus, only the ethanol extract could be considered as a potential source of anticancer and antioxidant compounds. Further phytochemical studies will be performed for specification of the biologically active principles.

Synergistic growth inhibition of mouse skin tumors by pomegranate fruit extract and diallyl sulfide: evidence for inhibition of activated MAPKs/NF-κB and reduced cell proliferation

Limited outcomes from earlier chemopreventive studies have necessitated that some modifications be made to get better efficacy. It is proposed that cancer prevention is more feasible than treatment, and this could be achieved effortlessly with use of multiple agents competent of targeting multiple targets. This study was initiated to examine the chemopreventive efficacy of pomegranate fruit extract (PFE) and diallyl sulfide (DAS), alone and in combination, using 2-stage mouse skin tumorigenesis model. PFE and DAS alone delayed onset and tumor incidence by ∼55% and ∼45%, respectively, while their combination at low doses synergistically decreased tumor incidence more potentially (∼84%, p<0.01). In addition, regression in tumor volume was seen with continuous combinatorial treatment (p<0.01). Mechanistic studies revealed that this inhibition was associated with decreased expression of phosphorylated ERK1/2, JNK1 and activated NF-κB/p65, IKKα, IκBα phosphorylation and degradation in skin tissue/tumor. Histological and cell death analysis also confirmed that combined PFE and DAS inhibit cellular proliferation and markedly induce apoptosis than the single agents. Altogether, our results suggest that PFE and DAS in combination impart better suppressive activity than either of these agents alone and provide support that development of novel combination therapies/chemoprevention using dietary agents will be more beneficial against cancer.

Antioxidant effect of garlic and aged black garlic in animal model of type 2 diabetes mellitus

Hyperglycemia in the diabetic state increases oxidative stress and antioxidant therapy can be strongly correlated with decreased risks for diabetic complications. The purpose of this study is to determine antioxidant effect of garlic and aged black garlic in animal model of type 2 diabetes. The antioxidant activity of garlic and aged black garlic was measured as the activity in scavenging free radicals by the trolox equivalent antioxidant capacity (TEAC) assay. Three week-old db/db mice were fed AIN-93G diet or diet containing 5% freeze-dried garlic or aged black garlic for 7 weeks after 1 week of adaptation. Hepatic levels of lipid peroxides and activities of antioxidant enzymes were measured. TEAC values of garlic and aged black garlic were 13.3 +/- 0.5 and 59.2 +/- 0.8 micromol/g wet weight, respectively. Consumption of aged black garlic significantly decreased hepatic thiobarbituric acid reactive substances (TBARS) level compared with the garlic group which showed lower TBARS level than control group (p<0.05). Activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of garlic and aged black garlic group were significantly elevated compared to the control group. Catalase (CAT) activity of aged black garlic group was increased compared with the control group. These results show that aged black garlic exerts stronger antioxidant activity than garlic in vitro and in vivo, suggesting garlic and aged black garlic, to a greater extent, could be useful in preventing diabetic complications.