The effects of aged garlic extract on lipid peroxidation and the deformability of erythrocytes

Effect of Garlic Extract on the Erythrocyte as a Simple Model Cell

Garlic is known to have diverse effects on mammalian cells, being cytotoxic, especially to cancer cells, but also protect against oxidative stress. Mammalian erythrocyte is a simple cell devoid of intracellular organelles, protein synthesis ability, and most signaling pathways. Therefore, examination of the effects of garlic on erythrocytes allows for revealing primary events in the cellular action of garlic extract. In this study, human erythrocytes or erythrocyte membranes were exposed to garlic extract at various dilutions. Hemoglobin oxidation to methemoglobin, increased binding of hemoglobin to the membrane, and formation of Heinz bodies were observed. Garlic extract depleted acid-soluble thiols, especially glutathione, and induced a prooxidative shift in the cellular glutathione redox potential. The extract increased the osmotic fragility of erythrocytes, induced hemolysis, and inhibited hemolysis in isotonic ammonium chloride, indicative of decreased membrane permeability for Cl- and increased the membrane fluidity. Fluorescent probes indicated an increased level of reactive oxygen species and induction of lipid peroxidation, but these results should be interpreted with care since the extract alone induced oxidation of the probes (dichlorodihydrofluorescein diacetate and BODIPY C11). These results demonstrate that garlic extract induces oxidative changes in the erythrocyte, first of all, thiol and hemoglobin oxidation.

Garlic against Heart-related Ailments: Chemistry, Pharmacology, and Future Perspective

BACKGROUND

Allium sativum L. (Garlic) is a well-recognized plant of great nutraceutical value with pharmacological evidences. It is full of dietary as well as pharmaceutical properties and has been used in traditional medications for a long time. It is known for good antioxidant, antifungal, antibacterial, anti-diabetic, anti-inflammatory, anticancer, and antiviral effects, along with other therapeutic roles in cardiovascular diseases, anti-atherosclerotic, antihypertensive, anti-thrombotic, blood pressure, bone and skin related problems etc. Objective: Considering the potential of garlic in the treatment of cardiovascular/heart-related diseases, the main objective of this study was to prepare a subject-centric mini-review focusing on its chemistry and pharmacology in heart-related issues.

METHODS

In order to prepare this mini-review article, an extensive online literature search was performed to find out the most recent studies related to this topic. These studies were briefly reviewed, assessed, and discussed to explore the possible capability of garlic for the cure of cardiovascular problems.

RESULT

Several experiments on mice models, rat models as well as on humans show the effective role of various forms of garlic in cardiovascular or heart-related ailments. After reviewing the available publications on garlic in heart-related issues, authors found that garlic and its sulfur (S)-based organic constituents may have advantageous applications in the treatment of cardiovascular diseases.

Effects of S-1-propenylcysteine, a sulfur compound in aged garlic extract, on blood pressure and peripheral circulation in spontaneously hypertensive rats

OBJECTIVES

This study was designed to investigate the antihypertensive effect of S-1-propenylcysteine, a characteristic sulfur compound in aged garlic extract, using a hypertensive rat model.

METHODS

The blood pressure and tail blood flow of both spontaneously hypertensive rats and control Wistar Kyoto rats were measured by the tail-cuff method and the noncontact laser Doppler method, respectively, at various times after single oral administration of a test compound for 24 h.

KEY FINDINGS

Treatment with S-1-propenylcysteine (6.5 mg/kg BW) significantly decreased the systolic blood pressure of spontaneously hypertensive rat approximately 10% at 3 h after administration, and thereafter, the systolic blood pressure gradually returned to the baseline level in 24 h. The effect of S-1-propenylcysteine was dose-dependent and was maximal at the dose of 6.5 mg/kg BW at 3 h. However, the other compounds such as S-allylcysteine and S-allylmercaptocysteine in aged garlic extract were ineffective. In addition, S-1-propenylcysteine had no effect on systolic blood pressure of control Wistar Kyoto rats. Furthermore, S-1-propenylcysteine significantly increased the blood flow at 3 h after administration at the dose of 6.5 mg/kg BW.

CONCLUSIONS

S-1-propenylcysteine is a key constituent of aged garlic extract responsible for its antihypertensive effect, and the effect of S-1-propenylcysteine involves the improvement in peripheral circulation.

Aged garlic extract inhibits peroxynitrite-induced hemolysis

Nitric oxide (NO), which is synthesized by constitutive NO synthase (cNOS), plays important roles in physiological functions of the cardiovascular system. However, NO, which is synthesized by inducible NOS, is detrimental when it reacts with superoxide to form peroxynitrite. Peroxynitrite is recognized as a powerful oxidant, and results in vascular or tissue damage. We have previously reported that aged garlic extract (AGE) enhances NO production through cNOS stimulation. In the present study, we determined the effect of AGE, its fractions or constituents on peroxynitrite-induced hemolysis using rat erythrocytes. Incubation of rat erythrocytes with peroxynitrite (300 microM) for 30 min at 37 degrees C caused 4-fold hemolysis. AGE (0.14-0.57 %w/v) added to an erythrocyte suspension was found to reduce peroxynitrite-induced hemolysis in a concentration-dependent manner. Of the AGE fractions, a polar fraction and a low-molecular-weight fraction both suppressed the hemolysis to the same degree as that seen with AGE. S-allylcysteine, one of the major compounds in AGE, also reduced hemolysis at 1-10 mM dose-dependently. These data indicate that AGE and its compounds protect erythrocytes from membrane damage induced by peroxynitrite, suggesting that AGE could be useful for prevention of cardiovascular diseases associated with oxidative stress or dysfunction of NO production.

Garlic intake is an independent predictor of endothelial function in patients with ischemic stroke

OBJECTIVES

To investigate the effects of garlic on endothelial function in patients with ischemic stroke (ISS).

DESIGN

Cross-sectional study.

PARTICIPANTS

125 Chinese patients with prior ISS due to athero-thrombotic disease were recruited from the outpatient clinics during July 2005 to December 2006.

MEASUREMENTS

Daily allium vegetable intake (including garlic, onions, Chinese chives and shallots) was ascertained by means of a validated food frequency questionnaire for Chinese and brachial artery flow-mediated dilatation (FMD) was measured using high-resolution ultrasound in all subjects.

RESULTS

The mean age of the study population was 65.9±11.1 years and 69% were males. Mean allium vegetable intake and garlic intake of the study population was 7.5±12.7g/day and 2.9±8.8g/day respectively. Their mean FMD was 2.6±2.3%. Daily intake of total allium vegetable (r=0.36, P<0.01) and garlic (r=0.34, P<0.01) significantly correlated with FMD. Using the median daily allium intake as cut-off (3.37g/day), patients with a low allium intake <3.37g/day was noted to have a lower FMD compared to those with a normal allium intake (2.1±2.1% versus 3.0±2.4%, P<0.05). After adjusting for confounding factors, multi-variate analysis identified that daily allium vegetable (B=0.05, 95% confidence interval: 0.02, 0.09, P<0.01) and garlic (B=0.07, 95% confidence interval: 0.02, 0.12, P<0.01) intake, but not onions, Chinese chives and shallots were independent predictors for changes in FMD in patients with ISS.

CONCLUSIONS

Daily garlic intake is an independent predictor of endothelial function in patients with ISS and may play a role in the secondary prevention of atherosclerotic events.

Garlic and cardioprotection: insights into the molecular mechanisms

Garlic is widely recognized for its immense therapeutic potential. Garlic has been shown to exert its beneficial effects against a wide spectrum of diseases, including cancer, diabetes, and microbial infections, as well as immunological and cardiovascular disorders. Most of the research on garlic has indicated that garlic and its active compounds are effective in reducing cardiovascular and metabolic risk by normalizing abnormal plasma lipids, oxidized low density lipoproteins, abnormal platelet aggregation, high blood pressure, and cardiac injury. Some of the beneficial effects of dietary garlic against cardiovascular disorders are mediated via the generation of hydrogen sulfide and nitric oxide in cardiomyocytes and endothelial cells. Garlic has the potential to protect the heart against myocardial infarction, doxorubicin-induced cardiotoxicity, arrhythmia, hypertrophy, and ischemia-reperfusion injury. The induction of cardiac endogenous antioxidants and the reduction of lipid peroxidation by garlic has been reported by several different groups. Other mechanisms, such as regulating ion channels, modulating Akt signaling pathways, histone deacetylase inhibition, and cytochrome P450 inhibition, could be responsible for the cardioprotective effect of garlic. Although several mechanisms have been identified for the cardioprotective effect of garlic, there is a need for further research to identify the specific molecular mechanism of cardioprotection in different cardiac diseases.

Renoprotective effect of aged garlic extract in streptozotocin-induced diabetic rats

OBJECTIVE

Aged garlic extract (AGE) has been proven to exhibit antioxidant, hypolipidemic, hypoglycemic and antidiabetic properties. However, its effect on diabetic nephropathy was unexplored. Therefore, the present study was designed to investigate the renoprotective effect of AGE in streptozotocin-induced diabetic rats.

MATERIALS AND METHODS

Albino Wistar rats were induced with diabetes by a single intraperitoneal injection of 45 mg/kg b.w. of streptozotocin. Commercially available AGE was supplemented orally at a dose of 500 mg/kg body weight/day. Aminoguanidine, which has been proven to be an anti-glycation agent was used as positive control and was supplemented at a dose of 1 g/L in drinking water. The serum and urinary biochemical parameters were analyzed in all the groups and at the end of 12 weeks follow up, the renal histological examination were performed using H & E and PAS staining.

RESULTS

The diabetic rats showed a significant change in the urine (P < 0.001) and serum (P < 0.01) constituents such as albumin, creatinine, urea nitrogen and glycated hemoglobin. In addition, the serum lipid profile of the diabetic rats were altered significantly (P < 0.05) compared to that of the control rats. However, the diabetic rats supplemented with aged garlic extract restored all these biochemical changes. The efficacy of the extract was substantiated by the histopathological changes in the kidney.

CONCLUSION

From our results, we conclude that aged garlic extract has the ability to ameliorate kidney damage in diabetic rats and the renoprotective effect of AGE may be attributed to its anti-glycation and hypolipidemic activities.

Prevention of selenite-induced cataractogenesis in Wistar albino rats by aqueous extract of garlic

PURPOSE

The main aim of this study was to evaluate the inhibitory impacts of the aqueous extract of garlic (Ga) on the formation of cataract induced by sodium selenite (Se).

METHODS

Thirty-two Wistar albino rat pups (4 equal groups: G1, G2, G3, and G4) were treated as follows: G1, subcutaneous (s.c.) and intraperitoneal (i.p.) injection of normal saline (0.3 mL) on postpartum (day 10); G2, i.p. injection of aqueous extract of garlic (1 mL/kg body weight) and s.c. injection of normal saline (0.3 mL) on postpartum (day 10); G3, s.c. injection of sodium selenite (20 nmol/g body weight) and i.p. injection of normal saline (0.3 mL) on postpartum (day 10); and G4, s.c. injection of sodium selenite (20 nmol/g body weight) and i.p. injection of aqueous extract of garlic (1 mL/kg body weight) on postpartum (day 10). Daily i.p. injections of aqueous extract of garlic (in G2 and G4) and normal saline (in G1 and G3) were continued for 14 days. The development of cataract was assessed over a period of 2 weeks after injection of sodium selenite. For further examination, the rats' lenses were removed and analyzed for glutathione (GSH), malondialdehyde (MDA) levels, and superoxide dismutase (SOD), glutathione peroxidase (GPX) activities.

RESULTS

In G3 (Se-treated group), all rats developed grade 3 cataract in both eyes. However, in G1 (untreated control group), G2 (Ga-treated group), and G4 (Ga-Se-treated group), the lenses in both eyes of all rats remained clear (P < 0.0001). This clinical finding was associated with higher GSH level and GPX, SOD activities and lower level of MDA in the Se- and Ga-treated group (G4) compared with SS-treated group (G3) rat lenses (P < 0.003).

CONCLUSIONS

Intraperitoneal injection of the Ga in rat model appeared to effectively prevent Se-induced cataract, thus such herbal remedy may be considered for treatment of cataract.

Comparative evaluation of adenosine deaminase activity in cerebral cortex and hippocampus of young and adult rats: effect of garlic extract (Allium sativum L.) on their susceptibility to heavy metal exposure

Adenosine plays an important neuromodulatory role in the central nervous system, and adenosine deaminase is an important enzyme in the degradation of adenine nucleotides. Methylmercury is the most prevalent form of mercury found in the environment. Methylmercury neurotoxicity has been correlated to the production of reactive oxygen species. In this study, its potential pathogenic effects were investigated in vitro in cerebral cortex and hippocampus of rats. We first observed that adenosine deaminase activity was higher in young rat brains when compared to the 60-day-old rats and was higher in hippocampus when compared to the cortex. Methylmercury (0.1, 1.0, 20 microM) inhibited adenosine deaminase activity in 7- and 60-day-old rats in a concentration-dependent manner. We have demonstrated that methylmercury-induced inhibition was antagonized by garlic alcoholic extract, but sodium selenate did not alter enzyme activity. In addition, glutathione and dithiothreitol restored the methylmercury-induced decrease of adenosine deaminase activity. These results demonstrated that there are age-related changes in adenosine deaminase activity and that thiol agents may contribute to the maintenance of adenosine deaminase activity and may be important in the neuromodulation of adenosine. Garlic alcoholic extract may be effective in reducing the effect of methylmercury-induced adenosine deaminase, which may be due to its sulphur-containing compounds.

Effects of a new nutraceutical ingredient on allergen-induced sulphidoleukotrienes production and CD63 expression in allergic subjects

Allergic diseases represent conditions affecting millions of individuals across the world. The objective of this study was to investigate the potential anti-allergic effects of a new nutraceutical ingredient, Pantescal (Bionap, Italy), contained in different food supplements. Pantescal is a mixture of plant extracts, such as Capparis spinosa, Olea europaea, Panax Ginseng and Ribes nigrum. The study was a randomized, double-blind, placebo controlled design. 60 patients allergic to common aeroallergens were chosen. Allergic patients were divided into two groups: one group was supplemented by Pantescal and the other, using a placebo formulation. Two in vitro tests were performed on blood samples taken from patients before and at 2 h, 2, 3 and 10 days after supplementation: cellular antigen stimulation test (CAST) was used to analyze the amount of sulphidoleukotrienes (SLT) production and flow-cytometric antigen stimulation test (FAST) to measure expression of basophil degranulation marker (CD63) was also performed. CAST showed that after 2 and 3 days, a slight decrease of SLT production was evident but only after 10 days did it become significant with a percentage of inhibition (P.I)=43.3%. FAST revealed that there were no statistical differences for the first 2 days after supplementation although there was an inhibitory trend in the supplemented patients. CD63 expression was significantly reduced after 10 days (P.I.=64.8%). This study suggests that Pantescal is effective in reducing allergic biomarkers such as CD63 protein and SLT in atopic subjects. The higher inhibitory effect on CD63 expression compared to SLT production allows us to hypothesize cell membrane stabilization as the main potential mechanism to explain the observed Pantescal protective effects.

Neuroprotective effects of garlic a review

Garlic has been investigated extensively for health benefits, resulting in more than one thousand publications over the last decade alone. It is considered one of the best disease preventive foods, based on its potent and varied effects. Midlife risk factors for cardiovascular diseases, such as high serum total cholesterol, raised LDL, increased LDL oxidation, increased platelet aggregation, impaired fibrinolysis, hypertension and homocystinemia are important risk factors for dementia in later years. These risk factors play a major role in the genesis of atherosclerosis of vital arteries causing both cardiovascular and cerebrovascular disease. Garlic is best known for its lipid lowering and anti-atherogenic effects. Possible mechanisms of action include inhibition of the hepatic activities of lipogenic and cholesterogenic enzymes that are thought to be the genesis for dyslipidemias, increased excretion of cholesterol and suppression of LDL-oxidation. Oxidative stress caused by increased accumulation of reactive oxygen species (ROS) in cells has been implicated in the pathophysiology of several neurodegenerative diseases including Alzheimer's disease (AD). Several studies have demonstrated the antioxidant properties of garlic and its different preparations including Aged Garlic Extract (AGE). AGE and S-allyl-cysteines (SAC), a bioactive and bioavailable component in garlic preparations have been shown in a number of in vitro studies to protect neuronal cells against beta-amyloid (A) toxicity and apoptosis. Thus the broad range of anti-atherogenic, antioxidant and anti-apoptotic protection afforded by garlic may be extended to its neuroprotective action, helping to reduce the risk of dementia, including vascular dementia and AD.

Protective effects of a freeze-dried extract of vegetables and fruits on the hydroxyl radical-mediated oxidative damage of DNA and decrease of erythrocytes deformability

The protective effects of a freeze-dried extracts of vegetables and fruits (BauYuan; BY) on the hydroxyl radical-mediated DNA strand breakages and the structural integrity of human red blood cells (RBCs) were investigated. First, the supercoiled plasmid (pEGFP-C1) DNA was subjected to oxidation damage by an ascorbate-fortified Fenton reaction and the protective effects were analyzed by agarose gel electrophoresis. In the absence of BY extracts, exposure of the high-throughput .OH-generating system (Fe2+ concentration >1.0 microM) caused a complete fragmentation of DNA. Supplementation of BY extract (1 mg/mL) to the plasmid DNA prior to the exposure could prevent it significantly. In contrast, as the plasmid exposed to a low-grade .OH-generating system (Fe2+<0.1 microM), the BY extract (1 mg/mL) provided an almost complete protection. Next, the cell deformabilities were measured to assess the protection effects of various BY extracts on human erythrocytes exposed to the oxidative insults. We found that both the aqueous extract and the organic solvent-derived extracts could strongly protect human RBCs from the reactive oxygen species (ROS)-mediated decrease in the deformability indices. The results implicated that the BY extracts could effectively protect the cell membrane integrity via scavenging ROS which enabling RBCs to maintain a balance of water content and surface area to prevent the drop of cell deformability.

Quantitative evaluation of the antioxidant properties of garlic and shallot preparations

OBJECTIVE

Shallots and garlic are an important part of the diet of many populations and there is long-held belief in their health enhancing properties. This study tested whether fresh and commercial shallot and garlic preparations have antioxidant properties that might justify such claims.

METHODS

Samples produced by pressing and extraction of bulbs were tested for their ability to decrease free radicals of 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) and the results were compared with commercial preparations of aged garlic and with trolox, butylated hydroxytoluene, N-acetyl cysteine, and gallic acid. We also measured the phenolic content of the extracts and the amounts of diallyl sulfides present.

RESULTS

Antioxidant activities were directly related to the contents of phenolic compounds, with the fresh freeze-dried extracts significantly more potent than commercial preparations. Hexane-extracted shallot and garlic had the highest antioxidant activity, followed by water extracts, bulb pressings, and commercial products. Fresh shallot and garlic preparations inhibited lipid oxidation and accelerated their decomposition but had no effect on protein oxidation.

CONCLUSIONS

Organic solvent and aqueous extracts of garlic and shallot bulbs had significant antioxidant potential, as measured by decreases in free radicals and an ability to inhibit lipid oxidation.

[Does garlic influence rheologic properties and blood flow in progressive systemic sclerosis?]

BACKGROUND

According to traditional European naturopathy garlic is an agent that increases perfusion. In studies with healthy subjects and in-vitro research garlic has shown influences on erythrocyte and thrombocyte aggregation as well as on vasoregulation. However, data on its effects in clinical populations are still lacking. Garlic may be useful for systemic sclerosis which is characterised by impaired perfusion that often cannot sufficiently be influenced by standard treatment. We investigated if dried garlic powder can influence rheologic properties and vasomotor function in systemic sclerosis.

SUBJECTS AND METHODS

During a randomised, double blind pilot study, 20 female inpatients with systemic sclerosis received a 7 day add-on therapy with either 900 mg dried garlic powder or placebo. Rheologic properties (erythrocyte aggregation, ADP-induced thromboycyte aggregation, plasma viscosity, fibrinogenous plasma level, blood sedimentation rate) were assessed initially as well as after 1 and 7 days of treatment. Vasomotor function was evaluated using near-infrared red photoplethysmography, a new diagnostic tool to assess microcirculation. Furthermore, acral skin temperature was measured.

RESULTS

After 7 days, only the verum treatment had induced a significant reduction of ADP-induced thrombocyte aggregation and a decrease in erythrocyte aggregation. Results showed no significant effects on vasomotor function, but an immediate effect of garlic on acral skin temperature.

DISCUSSION

According to the 'Qualitatenlehre' of traditional European naturopathy, garlic is classified as a 'heating agent'. Our results suggest that the improvement of rheologic properties could be a possible biological correlate for this. Although further research is required, we conclude garlic could be a rational add-on therapy in the 'Kaltekrankheit' ('cold disease') of systemic sclerosis.

Aged garlic extract improves blood pressure in spontaneously hypertensive rats more safely than raw garlic

We studied the effects of two garlic sources on systolic blood pressure (SBP) using spontaneously hypertensive rats (SHRs). Beginning at 12 wk of age, male SHRs were fed diets containing either aged garlic extract (AGE) or raw garlic (RG) powder for 10 wk. Both AGE and RG reduced the increase of SBP compared with the control group from 4 wk after beginning the experimental diets. The effect of AGE was accompanied by a decrease of pulse pressure (PP), suggesting an improvement of the pliability of the artery, although RG did not affect PP. However, harmful effects were observed in the RG group, including a decrease in erythrocytes, an increase in reticulocytes, and generation of papilloma in the forestomach. These results suggest that AGE may safely improve several factors related to blood vessel physiology and circulatory disease.

Garlic and cardiovascular disease: a critical review

Epidemiologic studies show an inverse correlation between garlic consumption and progression of cardiovascular disease. Cardiovascular disease is associated with multiple factors such as raised serum total cholesterol, raised LDL and an increase in LDL oxidation, increased platelet aggregation, hypertension, and smoking. Numerous in vitro studies have confirmed the ability of garlic to reduce these parameters. Thus, garlic has been shown to inhibit enzymes involved in lipid synthesis, decrease platelet aggregation, prevent lipid peroxidation of oxidized erythrocytes and LDL, increase antioxidant status, and inhibit angiotension-converting enzyme. These findings have also been addressed in clinical trials. The studies point to the fact that garlic reduces cholesterol, inhibits platelet aggregation, reduces blood pressure, and increases antioxidant status. Since 1993, 44% of clinical trials have indicated a reduction in total cholesterol, and the most profound effect has been observed in garlic's ability to reduce the ability of platelets to aggregate. Mixed results have been obtained in the area of blood pressure and oxidative-stress reduction. The findings are limited because very few trials have addressed these issues. The negative results obtained in some clinical trials may also have resulted from usage of different garlic preparations, unknown active constituents and their bioavalability, inadequate randomization, selection of inappropriate subjects, and short duration of trials. This review analyzes in vitro and in vivo studies published since 1993 and concludes that although garlic appears to hold promise in reducing parameters associated with cardiovascular disease, more in-depth and appropriate studies are required.

Aged garlic extract may be safe for patients on warfarin therapy

Garlic has been known to have antiplatelet properties. Because of the lack of major clinical data regarding the safety of concomitant use of garlic supplements and anticoagulants, we decided to evaluate the safety of using garlic extract along with oral anticoagulation therapy. During this project we tested aged garlic extract (AGE), a commercial garlic preparation, with warfarin (Coumadin). Sixty-six (66) patients were screened for a double-blind, randomized, placebo-controlled pilot study. Fifty-two (52) patients were randomized for the project. Forty-eight patients (30 men and 18 women, with a mean age of 56+/-10 years) completed the study. Eighteen patients (14 before randomization, 4 after randomization) were dropped from the study. The study medication (AGE or placebo) was administered at a dose of 5 mL twice a day for 12 wk. Potential bleeding and thromboembolic episodes were monitored. There was no evidence of increased hemorrhage in either the placebo or the AGE group. Adverse events included headache, fatigue, colds, and dizziness. However, no significant difference was found in the incidence of these minor adverse events between the groups. Thus, the adverse events are unlikely to be attributable to AGE. The results suggest that AGE is relatively safe and poses no serious hemorrhagic risk for closely monitored patients on warfarin oral anticoagulation therapy. Although the risk-benefit ratio of AGE use needs to be considered carefully when warfarin therapy is necessary, its positive effects may be beneficial to people with a high-risk background or who are taking cardiovascular medications.

Aged garlic extract maintains cardiovascular homeostasis in mice and rats

Nitric oxide (NO) plays an important role in controlling the physiological functions of the cardiovascular system. However, toxic peroxynitrite is produced by the reaction of NO with superoxide. We investigated the effect of aged garlic extract (AGE) on NO production, and on oxidative stress induced by peroxynitrite. A single dose of AGE temporarily increased NO production by 30-40% between 15 and 60 min after administration to mice. The time course of the fluctuation in NO levels in the AGE-treated group clearly differed from that in a group treated with an inducible NO synthase (iNOS) inducer. A selective constitutive NOS (cNOS) inhibitor overcame the effect of AGE. These results indicate that AGE increases NO production by activating cNOS, but not iNOS. In another experiment, the addition of AGE to a rat erythrocyte suspension reduced the rate of peroxynitrite-induced hemolysis in a concentration-dependent manner, suggesting that AGE protects erythrocytes from membrane damage induced by peroxinitrite. Because an increase in NO derived from cNOS and protection against peroxynitrite are important factors in the prevention of cardiovascular disease, our data strongly suggest that AGE could be useful in preventing cardiovascular diseases associated with oxidative stress or dysfunctions of NO production.

Aged garlic extract is a potential therapy for sickle-cell anemia

Sickle-cell anemia is one of the most prevalent hereditary disorders with prominent morbidity and mortality. Oxidative phenomena play a significant role in the disorder's pathophysiology. A forumlation of garlic (Allium sativum), AGE, has been reported to exert an antioxidant effect in vitro. We evaluated the antioxidant effect of AGE on sickle red blood cells (RBCs). Five patients (two men and three women, mean age 40+/-15 years, range 24-58 years) with sickle-cell anemia participated in the study. AGE was administered at a dose of 5 mL daily. Whole blood samples were obtained at baseline and at 4 wk, primarily for Heinz body analysis. In all patients, the number of Heinz bodies decreased over the 4-wk period (58.9+/-20.0% at baseline to 29.8+/-15.3% at follow-up; P=0.03). These data suggest that AGE has a significant antioxidant activity on sickle RBCs. AGE may be further evaluated as a potential therapeutic agent to ameliorate complications of sickle-cell anemia.

Role of diallyl tetrasulfide in ameliorating the cadmium induced biochemical changes in rats

Cadmium (Cd) is an ubiquitous environmental and occupational toxic metal concerned with a variety of adverse effects. The present study was undertaken to evaluate the role of diallyl tetrasulfide (DTS), an organosulfur compound in alleviating the Cd induced biochemical changes in male Wistar rats. During the experiment, rats were injected with Cd (3mg/(kgday)) subcutaneously alone or with oral administration of DTS at different doses (10, 20 and 40mg/(kgday)) for 3 weeks. In Cd treated rats, the activities of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and gamma glutamyl transferase (GGT) were significantly increased in serum with elevated levels of bilirubin, urea and creatinine. The hemoglobin level and creatinine clearance were also significantly decreased in Cd treated rats. In addition, the levels of plasma lipid peroxidation markers: thiobarbituric acid reactive substances and lipid hydroperoxides were significantly increased while the levels of plasma reduced glutathione (GSH), Vitamins C and E were significantly decreased in Cd administered rats. Administration of DTS along with Cd significantly decreased the serum, liver and kidney markers towards near normal level in a dose dependent manner. DTS at a dose of 40mg/(kgday) was highly effective when compared to other doses (10 and 20mg/(kgday)). DTS also significantly reduced the accumulation of Cd in blood and tissues as well as decreased the level of lipid peroxidation markers with elevation of antioxidants in plasma. All these changes were accompanied by histological observations in liver. The obtained results demonstrated the beneficial effect of DTS in reducing the harmful effects of Cd.

Organosulfur compounds from alliaceae in the prevention of human pathologies

A strong association between elevated plasma low-density-lipoprotein (LDL) and the development of cardiovascular diseases (CVD) has been established. Oxidation of LDL (Ox-LDL) promotes vascular dysfunction, enhances the production and release of inflammatory mediators such as reactive oxygen species and contribute to the initiation and progression of atherosclerosis. In addition, Ox-LDL enhances the production and release of tumor necrosis factor (TNF-alpha), interleukin (IL)-6, arachidonic acid metabolites and nitric oxide (NO) that are responsible for various human pathologies including cancer. Organosulfur compounds (OSC) from alliaceae modulate the glutathione (GSH) redox cycle and inhibits NFkappa-B activation in human T cells. Furthermore, OSC bioactivities include antioxidant, antibacterial, anticarcinogenic, antiatherogenic, immunostimulatory, and liver protection potential.

Garlic and aging: new insights into an old remedy

There has been an impressive gain in individual life expectancy with parallel increases in age-related chronic diseases of the cardiovascular, brain and immune systems. These can cause loss of autonomy, dependence and high social costs for individuals and society. It is now accepted that aging and age-related diseases are in part caused by free radical reactions. The arrest of aging and stimulation of rejuvenation of the human body is also being sought. Over the last 20 years the use of herbs and natural products has gained popularity and these are being consumed backed by epidemiological evidence. One such herb is garlic, which has been used throughout the history of civilization for treating a wide variety of ailments associated with aging. The role of garlic in preventing age-related diseases has been investigated extensively over the last 10-15 years. Garlic has strong antioxidant properties and it has been suggested that garlic can prevent cardiovascular disease, inhibit platelet aggregation, thrombus formation, prevent cancer, diseases associated with cerebral aging, arthritis, cataract formation, and rejuvenate skin, improve blood circulation and energy levels. This review provides an insight in to garlic's antioxidant properties and presents evidence that it may either prevent or delay chronic diseases associated with aging.

Effect of aged garlic extract on caspase-3 activity, in vitro

In neurodegeneration, such as Alzheimer's disease (AD), apoptosis results in the loss of valuable neurons. A key mechanism in apoptosis is the activation of caspase-3. Caspase-3 activity first becomes detectable early in apoptosis, continues to increase as cells undergo apoptosis, and rapidly declines in late stages of apoptosis. Its activity is an early marker of cells undergoing apoptosis. Caspase-3 catalyzes the formation of beta-amyloid peptide, a hallmark of AD. The purpose of the study was to determine whether dietary aged garlic extract (AGE), with known antioxidant properties and neuroprotection against Alzheimer's beta-amyloid cytotoxicity, inhibits the caspase-3 activity in vitro. Caspase-3 activity was assayed according to the prescribed protocol and incubated overnight at ambient temperature. We report that AGE inhibits caspase-3 in dose dependent manner. Caspase-8 was not inhibited by AGE. As a caspase-3 inhibitor, AGE may be effective in reducing apoptotic death of neurons since caspase inhibitors have been shown to inhibit neuronal cell death. We propose a scheme for the ameliorative effect of AGE on deleterious effects of beta-amyloid and possibly uncontrolled caspase-3 activity.

Aged garlic extract therapy for sickle cell anemia patients

BACKGROUND: Sickle cell anemia is one of the most prevalent hereditary disorders with prominent morbidity and mortality. With this disorder oxidative, phenomena play a significant role in its pathophysiology. One of the garlic (Allium sativum L.) formulations, aged garlic extract (AGE), has been reported to exert an anti-oxidant effect in vitro, we have evaluated the anti-oxidant effect of AGE on sickle red blood cells (RBC). METHODS: Five patients (two men and three women, mean age 40 ± 15 years, range 24-58 years) with sickle cell anemia participated in the study. AGE was administered at a dose of 5 ml a day. Whole blood samples were obtained at baseline and at 4 weeks for primarily Heinz body analysis. RESULTS: The data were consistent with our hypothesis. In all patients, the number of Heinz bodies decreased over the 4 week period (58.9 ± 20.0% at baseline to 29.8 ± 15.3% at follow-up, p = 0.03). CONCLUSIONS: These data suggest that there is a significant anti-oxidant activity of AGE on sickle RBC. AGE may be further evaluated as a potential therapeutic agent to ameliorate complications of sickle cell anemia.