Propiedades del ajo

1. Antimicrobiano
La alicina y otros compuestos con azufre, presente en el bulbo del ajo o formados a partir de ellos, son activos contra el H pylori, estafilococos, E. coli y otras bacterias comunes. Asimismo han demostrado actividad contra ciertos hongos, virus y protozoarios. Su actividad se manifiesta bajo los distintos preparados e incluso crudo machacado. Obviamente su actividad es menor a la de los antibióticos específicos. Mayoritariamente se indica su uso externo, como antiséptico.

2. Antioxidante
El dialil sulfato, formado por descomposición de la alicina, neutraliza radicales libres e impide la oxidación de lípidos como el LDL, proceso importante en la arterioesclerosis.

3. Diabetes
Se ha demostrado que los principios activos de ajo reducen los niveles de glucosa en sangre, uno de los mecanismos sería mediante el aumento de consumo de glucosa por el músculo.
Otro efecto en personas con diabetes sería la protección sobre el músculo cardíaco, proclive a la cardiomiopatía diabética, esto asociado con el poder antioxidante de la planta.

4. Hipertensión, ateroesclerosis y otros temas vasculares
La inhibición de la producción del óxido nítrico, uno de los responsables del aumento de la presión arterial, sería el mecanismo de acción involucrado en la acción de controlar la presión arterial.
Tal como se ha establecido el ajo tiene propiedades antioxidantes que interfieren con la oxidación lipídica y por ende contribuyen a la disminución del daño arterial. Del mismo modo esta actividad antiradicales protege al músculo cardíaco.
Su actividad de descenso de los niveles de colesterol y ácidos grasos en sangre no ha sido totalmente comprobado.

5. Cáncer
Los compuestos azufrados derivados de la aliína promueven la actividad de los procesos de desintoxicación celular que impiden la formación de células tumorales, esto a nivel mitocondrial, junto a la activación de otros procesos celulares, como la inducción de la apoptosis de las células tumorales.

Compuestos presentes en el ajo añejado tienen, al parecer, un comportamiento más eficaz.

1.1 Love That Garlic? Fresh May Be Healthier Than Bottled . Le gusta el ajo? Fresco podría ser más saludable que envasado. ScienceDaily (June 12, 2008)
The next time you use garlic for its renowned antibacterial effects, consider fresh garlic instead of those bottles of chopped garlic. Researchers in Japan report that fresh garlic maintains higher levels of a key healthy ingredient than preserved versions and may be better for you.
In the new study, Toyohiko Ariga and colleagues point out that allicin is one of the main active ingredients in garlic. Other studies have shown that allicin has beneficial effects in preventing blood clots, cancer, and bacterial infection. Although commercially bottled garlic is often stored in oil or water, researchers did not know how various storage and preservation methods affect levels of allicin, which is fragile and disappears quickly.
To find out, Ariga’s group compared allicin levels in extracts of fresh garlic after 1-2 weeks of storage in water, alcohol, and vegetable oil. Garlic stored in water at room temperature lost about half its allicin in 6 days and garlic in vegetable oil lost half its allicin in less than an hour. The garlic lost its antibacterial action as allicin broke down. However, allicin broke down into materials that still are believed to have some anticancer and anti-blood clot effects.
Journal Reference:Fujisawa et al. Biological and Chemical Stability of Garlic-Derived Allicin. Journal of Agricultural and Food Chemistry, 2008; 56 (11): 4229 DOI: 10.1021/jf8000907

1.2 Antibacterial and antioxidant effect of crude garlic extract in meat. Efectos antibacterianos y antioxidantes en la carne del extracto crudo de ajo.
El-Zeini-S; Atta-AH
AD: Animal Health Research Institute, Dokki, and Faculty of Vet. Med., Cairo University Giza, Egypt.
Veterinary-Medical-Journal-Giza. 1997, 45: 1, 37-45. : 1997
AB: The antibacterial and antioxidant effects of crude garlic extract (2.5, 5, 10 or 20%) on Escherichia coli and Staphylococcus aureus were examined in fresh lean beef muscle samples obtained from an abattoir in Cairo, Egypt. The garlic extract reduced the number of bacteria attached to muscle samples in a dose-dependent fashion. It also significantly decreased values of thiobarbituric acid, peroxide and kreis optical density in meat kept in the refrigerator for 1, 3 and 5 days, showing that the garlic extract had an antioxidative effect.

1.3 Effect of Allium spp. and herb extracts on food-borne pathogens, procaryotic, and higher and lower eucaryotic cell lines. Nolan-LL; McClure-CD; Labbe-RG; Craker-LE; Nolan-L ; Shetty-K
School of Public Health and Health Sciences, University of Massachusetts, Amherst, MA 01003, USA.
International symposium on medicinal and aromatic plants, Amherst, Massachusetts, USA, 27-30 Aug. 1995.
Acta-Horticulturae. 1996, No. 426, 277-285; 23 ref. PY: 1996
Certain foodborne bacterial pathogens (Salmonella typhimurium, Shigella dysenteriae, Clostridium perfringens, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus) were tested for their sensitivity to allicin, a major component of garlic extracts. Allicin was chemically synthesized and purified by HPLC and its inhibitory activity against the bacteria was determined using a disc sensitivity plate assay. All bacteria were inhibited by allicin in a dose-dependent manner. In addition, protozoal parasites (Leishmania mexicana and L. chagasi [L. infantum chagasi]) and mammalian cell lines (HeLa and CEM T4 cells), whose sensitivities to natural herbs were undetermined, were tested for susceptibility to aqueous and ethanolic plant extracts of several species including nutmeg (Myristacea [Myristica] spp.), ginger (Zingiber officinale), goldenseal root (Hydrastis canadensis), garlic (Allium sativum), elephant garlic (Allium scorodoprasum), onion (Allium cepa) and licorice (Glycyrrhiza glabra). Inhibition of HeLa and leishmanial cells was expressed as IC50 values in æg/ml. L. chagasi was more sensitive to both types of garlic than L. mexicana (IC50 values of 70 and 32 æg/ml for A. sativum and A. scorodoprasum, respectively). Extracts from raw onion did not inhibit growth of any of the cell lines. G. glabra extracts inhibited leishmanial parasites but were not toxic to HeLa cells. All the other extracts showed varying inhibitory activities.

2.1 Antioxidant and radical scavenging effects of aged garlic extract and its constituents. Efectos antioxidante y antiradicales libres del ajo añejado.
Imai-J; Ide-N; Nagae-S; Moriguchi-T; Matsuura-H; Itakura-Y
Institute for OTC Research, Wakunaga Pharmaceutical Co. Ltd., 1624 Shimokotachi, Koda-cho, Takata-gun, Hiroshima, 729-64, Japan.
Planta-Medica. 1994, 60: 5, 417-420; 31 ref. 1994
AB: The antioxidant properties of 3 garlic clove preparations and their organosulphur compounds were investigated, using the chemiluminescence and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays. Aged garlic extract inhibited the emission of low level chemiluminescence and the early formation of thiobarbituric acid-reactive substances in isolated rat liver microsomes, whereas the water extracts of raw and heat-treated garlic increased the emission of low level chemiluminescence. S-Allylcysteine and S-allylmercaptocysteine, the major organosulphur compounds in aged garlic extract, showed radical scavenging activity in both the chemiluminescence and the DPPH assays.

2.2 Effect of the active principle of garlic – diallyl sulfide – on cell viability, detoxification capability and the antioxidation system of primary rat hepatocytes. Efecto del dialilsulfuro en la viabilidad celular, capacidad desintoxicante y en el sistema antioxidante en hepatocitos primarios de ratas.
Sheen-LY; Lii-CK; Sheu-SF; Meng-RHC; Tsai-SJ
Department of Nutrition, China Medical College, Taichung, Taiwan.
Food-and-Chemical-Toxicology. 1996, 34: 10, 971-978; 8 pl.; 30 ref. 1996
AB: The objectives of this study were to investigate the effects of various concentrations and incubation time intervals of diallyl sulfide (DAS), an active principle of garlic, on cell viability, and glutathione (GSH) concentration and its related enzymes activities in rat hepatocytes. According to the results of lactate dehydrogenase (LDH) leakage and microscopic examination, 0.5 or 1 mM DAS treatment did not have any adverse effects on the viability of hepatocytes. Intracellular GSH contents of cells treated with 0.5 and 1 mM DAS (58.6 and 66.4 nmol GSH/mg protein, respectively) were higher than in the controls (54.2 nmol GSH/mg protein), around 8-23%, after 24 h of incubation; a significant difference was observed for 1 mM DAS treatment at 48 h. This phenomenon is beneficial to the detoxification and antioxidation capabilities of hepatocytes. Further, when the hepatocytes were treated with 0.5 or 1 mM DAS, the activities of glutathione S-transferase (GST), glutathione peroxidase (GPx) and glutathione reductase (GRd) were almost the same as those of the controls. On the other hand, treatment with 5 mM DAS was associated with a significant decrease in cell viability, namely in increased LDH leakage (50% at 24-h treatment), significant changes in the morphology of the hepatocytes, low intracellular GSH level (45% lower than in the controls after 24 h of treatment), and low activities of GST, GPx and Grd.

2.3 Antioxidant health effects of aged garlic extract. Efectos antioxidantes del extracto de ajo añejado.
J Nutr. 2001 Mar;131(3s):1010S-5S
Borek C.
Department of Community Health and Family Medicine, Nutrition and Infectious Diseases Unit, Tufts University School of Medicine, Boston, MA 02111, USA.
Oxidative modification of DNA, proteins and lipids by reactive oxygen species (ROS) plays a role in aging and disease, including cardiovascular, neurodegenerative and inflammatory diseases and cancer. Extracts of fresh garlic that are aged over a prolonged period to produce aged garlic extract (AGE) contain antioxidant phytochemicals that prevent oxidant damage. These include unique water-soluble organosulfur compounds, lipid-soluble organosulfur components and flavonoids, notably allixin and selenium. Long-term extraction of garlic (up to 20 mo) ages the extract, creating antioxidant properties by modifying unstablemolecules with antioxidant activity, such as allicin, and increasing stable and highly bioavailable water-soluble organosulfur compounds, such as S-allylcysteine and S-allylmercaptocysteine. AGE exerts antioxidant action by scavenging ROS, enhancing the cellular antioxidant enzymes superoxide dismutase, catalase andglutathione peroxidase, and increasing glutathione in the cells. AGE inhibits lipid peroxidation, reducing ischemic/reperfusion damage and inhibiting oxidative modification of LDL, thus protecting endothelial cells from the injury by the oxidized molecules, which contributes to atherosclerosis. AGE inhibits the activation of the oxidant-induced transcription factor, nuclear factor (NF)-kappa B, which has clinical significance in human immunodeficiency virus gene expression and atherogenesis. AGE protects DNA against free radical–mediated damage and mutations, inhibits multistep carcinogenesis and defends against ionizing radiation and UV-induced damage, including protection against some forms of UV-induced immunosuppression. AGE may have a role in protecting against loss of brain function in aging and possess other antiaging effects, as suggested by its ability to increase cognitive functions, memory and longevity in a senescence-accelerated mouse model. AGE has been shown to protect against the cardiotoxic effects of doxorubicin, an antineoplastic agent used in cancer therapy and against liver toxicity caused by carbon tetrachloride (an industrial chemical) and acetaminophen, an analgesic. Substantial experimental evidence shows the ability of AGE to protect against oxidant-induced disease, acute damage from aging, radiation and chemical exposure, and long-term toxic damage. Although additional observations are warranted in humans, compelling evidence supports the beneficial health effects attributed to AGE, i.e., reducing the risk of cardiovascular disease, stroke, cancer and aging, including the oxidant-mediated brain cell damage that is implicated in Alzheimer’s disease.

2.4 Comparison of the main bioactive compounds and antioxidant activities in garlic and white and red onions after treatment protocols. Comparación de los compuestos bioactivos más importantes de ajo y cebollas blancas y rojas y de sus propiedades antioxidantes.
Gorinstein S, Leontowicz H, Leontowicz M, Namiesnik J, Najman K, Drzewiecki J, Cvikrová M, Martincová O, Katrich E, Trakhtenberg S.
J Agric Food Chem. 2008 Jun 25;56(12):4418-26.
Department of Medicinal Chemistry and Natural Products, The Hebrew University, Hadassah Medical School, P.O. Box 12065, Jerusalem 91120, Israel. gorin@cc.huji.ac.il
Polish garlic and white and red onions were subjected to blanching, boiling, frying, and microwaving for different periods of time, and then their bioactive compounds (polyphenols, flavonoids, flavanols, anthocyanins, tannins, and ascorbic acid) and antioxidant activities were determined. It was found that blanching and frying and then microwaving of garlic and onions did not decrease significantly the amounts of their bioactive compounds and the level of antioxidant activities ( P > 0.05). The HPLC profiles of free and soluble ester- and glycoside-bound phenolic acids showed that trans-hydroxycinnamic acids (caffeic, p-coumaric, ferulic, and sinapic) were as much as twice higher in garlic than in onions. Quercetin quantity was the highest in red onion among the studied vegetables.The electrophoretic separation of nonreduced garlic and onion proteins after boiling demonstrated their degradation in the range from 50 to 112

2.5 Garlic Increases Antioxidant Levels in Diabetic and Hypertensive Rats Determined by a Modified Peroxidase Method El ajo aumenta los niveles antioxidantes en ratas diabéticas e hipertensivas.
Drobiova H, Thomson M, Al-Qattan K, Peltonen-Shalaby R, Al-Amin Z, Ali M.
Evid Based Complement Alternat Med. 2009 Feb 20.
Department of Biological Sciences, Faculty of Science, Kuwait University, P.O. Box 5969, 13060-Safat, Kuwait. mmtkuwait2003@hotmail.com.
Oxidative damage by free radicals has been implicated in the pathogenesis of vascular disease in diabetes and hypertension. In the present study, the total antioxidant status in diabetic and hypertensive rats before and after treatment with garlic (Allium sativum) was determined. The total serum antioxidants were measured by a modified method reported earlier by Miller and coworkers. The reproducibility of the assay was confirmed by determining standard curves for the known antioxidants: trolox (a stable analog of vitamin E), glutathione and vitamin C with interassay correlation coefficients (R(2), n = 10 in triplicate) of 0.9984, 0.9768 and 0.987, respectively, confirming the reliability and reproducibility of the assay. This assay was then used to determine total serum antioxidant levels of streptozotocin-induced diabetic rats and two-kidney one-clip hypertensive rats both before and after 3 weeks of treatment with an aqueous extract of garlic (500 mg/kg IP daily). The serum antioxidant levels of rats after 3 weeks of treatment were significantly higher (P < 0.001) than the pretreatment levels in both diabetic and hypertensive rats. The increased serum antioxidant levels were paralleled by a decrease in serum glucose in the garlic-treated diabetic rats and lowered systolic blood pressure in the garlic-treated hypertensive rats. We conclude from our study that (i) total antioxidants can be measured by a simple, reproducible, reliable assay and (ii) the total antioxidant status can be significantly improved by treatment with garlic.

2.6 Antioxidant and radical scavenging effects of aged garlic extract and its constituents. Efectos antioxidantes y antiradicales libres del extracto de ajo añejado y de sus componentes.
Imai-J; Ide-N; Nagae-S; Moriguchi-T; Matsuura-H; Itakura-Y
Institute for OTC Research, Wakunaga Pharmaceutical Co. Ltd.,
1624 Shimokotachi, Koda-cho, Takata-gun, Hiroshima, 729-64, Japan.
Planta-Medica. 1994, 60: 5, 417-420; 31 ref. 1994
AB: The antioxidant properties of 3 garlic clove preparations and their organosulphur compounds were investigated, using the chemiluminescence and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays. Aged garlic extract inhibited the emission of low level chemiluminescence and the early formation of thiobarbituric acid-reactive substances in isolated rat liver microsomes, whereas the water extracts of raw and heat-treated garlic increased the emission of low level chemiluminescence. S-Allylcysteine and S-allylmercaptocysteine, the major organosulphur compounds in aged garlic extract, showed radical scavenging activity in both the chemiluminescence and the DPPH assays.

2.7 Effect of the active principle of garlic – diallyl sulfide – on cell viability, detoxification capability and the antioxidation system of primary rat hepatocytes.

Sheen-LY; Lii-CK; Sheu-SF; Meng-RHC; Tsai-SJ
Department of Nutrition, China Medical College, Taichung, Taiwan.
Food-and-Chemical-Toxicology. 1996, 34: 10, 971-978; 8 pl.; 30 ref. 1996
The objectives of this study were to investigate the effects of various concentrations and incubation time intervals of diallyl sulfide (DAS), an active principle of garlic, on cell viability, and glutathione (GSH) concentration and its related enzymes activities in rat hepatocytes. According to the results of lactate dehydrogenase (LDH) leakage and microscopic examination, 0.5 or 1 mM DAS treatment did not have any adverse effects on the viability of hepatocytes. Intracellular GSH contents of cells treated with 0.5 and 1 mM DAS (58.6 and 66.4 nmol GSH/mg protein, spectively) were higher than in the controls  (54.2 nmol GSH/mg protein), around 8-23%, after 24 h of incubation; a significant difference was observed for 1 mM DAS treatment at 48 h. This phenomenon is beneficial to the detoxification and antioxidation capabilities of hepatocytes. Further, when the hepatocytes were treated with 0.5 or 1 mM DAS, the activities of glutathione S-transferase (GST), glutathione peroxidase (GPx) and glutathione reductase (GRd) were almost the same as those of the controls. On the other hand, treatment with 5 mM DAS was associated with a significant decrease in cell viability, namely in increased LDH leakage (50% at 24-h treatment), significant changes in the morphology of the hepatocytes, low intracellular GSH level (45% lower than in the controls after 24 h of treatment), and low activities of GST, GPx and Grd.

3.1 Effect of aqueous extracts of garlic (Allium sativum) and onion (Allium cepa) on lipid and carbohydrate metabolism in alloxan-diabetic mice. Efectos de extractos acuosos de ajo en los metabolismos de lípidos y carbohidratos en ratones diabéticos por aloxano.

AU: Al-Salahy-MB; Hassanien-AA
SO: Assiut-Veterinary-Medical-Journal. 1993, 30: 59, 32-40; 16 ref.
AB: Normal and alloxan-induced diabetic mice were given a standard diet + water containing an aqueous extract of garlic (0.03% w/v) or onions (0.05% w/v). After 7 days, the animals were sacrificed. The garlic-treated mice, as compared with untreated diabetic animals, showed significantly lower blood glucose, liver glycogen and total lipid contents, and significantly increased muscle glycogen levels, suggesting that garlic extract may enhance the uptake of glucose by muscle in diabetic animals. The onion extract also resulted in decreased total lipid contents in the liver and muscle tissue but had no effect on blood glucose or glycogen levels in liver or muscle. It is concluded that garlic and onion extracts have antidiabetic properties, and that onion extracts are less potent than garlic extracts.

3.2 Anti-diabetic effects of onion and garlic sulfoxide amino acids in rats. Efectos antidiabéticos de los sulfuros de cebollas y ajos, en ratas.

AU: Sheela-CG; Kumari-Kumud; Augusti-KT; Kumud-KAD: Department of Biochemistry, University of Kerala, Thiruvananthapuram 695-581, India.SO: Planta-Medica. 1995, 61: 4, 356-357; 12 ref.PY: 1995LA: EnglishAB: S-methylcysteine sulfoxide (SMCS), isolated from Allium cepa, or S-allylcysteine sulfoxide (SACS), isolated from A. sativum, were administered at 200 mg/kg, p.o., daily for one month to alloxan-diabetic rats. Both compounds exhibited a weaker antidiabetic activity than the standard drugs, glibenclamide and insulin, judged by their effects on glucose intolerance, weight loss, depletion of liver glycogen and other parameters. However, in contrast to the standard drugs, SMCS and SACS did not stimulate the synthesis of cholesterol, a risk factor associated with heart attack.

3.3 Garlic Oil Shows Protective Effect Against Heart Disease in Diabetes. El aceite de ajo muestra efectos protectores contra la enfermedad cardíaca (cardiomiopatía) en la diabetes.

ScienceDaily (Oct. 1, 2010).
Garlic has «significant» potential for preventing cardiomyopathy, a form of heart disease that is a leading cause of death in people with diabetes, scientists have concluded in a new study. Their report, which also explains why people with diabetes are at high risk for diabetic cardiomyopathy, appears in ACS’ bi-weekly Journal of Agricultural and Food Chemistry.
Wei-Wen Kuo and colleagues note that people with diabetes have at least twice the risk of death from heart disease as others, with heart disease accounting for 80 percent of all diabetes-related deaths. They are especially vulnerable to a form of heart disease termed diabetic cardiomyopathy, which inflames and weakens the heart’s muscle tissue. Kuo’s group had hints from past studies that garlic might protect against heart disease in general and also help control the abnormally high blood sugar levels that occur in diabetes. But they realized that few studies had been done specifically on garlic’s effects on diabetic cardiomyopathy.
The scientists fed either garlic oil or corn oil to laboratory rats with diabetes. Animals given garlic oil experienced beneficial changes associated with protection against heart damage. The changes appeared to be associated with the potent antioxidant properties of garlic oil, the scientists say, adding that they identified more than 20 substances in garlic oil that may contribute to the effect.
«In conclusion, garlic oil possesses significant potential for protecting hearts from diabetes-induced cardiomyopathy,» the report notes.
Editor’s Note: This article is not intended to provide medical advice, diagnosis or treatment.
Journal Reference:Hsiu-Chung Ou, Bor-Show Tzang, Mu-Hsin Chang, Cheng-Tzu Liu, Hui Wen Liu, Chong-Kuei Lii, Da-Tian Bau, Pei-Min Chao, Wei-Wen Kuo. Cardiac Contractile Dysfunction and Apoptosis in Streptozotocin-Induced Diabetic Rats Are Ameliorated by Garlic Oil Supplementation. Journal of Agricultural and Food Chemistry, 2010; 100913154526047 DOI: 10.1021/jf101606s

3.4 Does garlic have a role as an antidiabetic agent? Posee el ajo un rol como agente antidiabético?Mol Nutr Food Res. 2007 Nov;51(11):1353-64.
Liu CT, Sheen LY, Lii CK.
Department of Nutrition, Chung Shan Medical University, Taichung, Taiwan, PR China.
Diabetes affects a large segment of the population worldwide, and the prevalence of this disease is rapidly increasing. Despite the availability of medication for diabetes, traditional remedies are desirable and are currently being investigated. Garlic (Allium sativum), which is a common cooking spice and has a long history as a folk remedy, has been reported to have antidiabetic activity. However, there is no general agreement on the use of garlic for antidiabetic purposes, primarily because of a lack of scientific evidence from human studies and inconsistent data from animal studies. The validity of data from previous studies of the hypoglycemic effect of garlic in diabetic animals and the preventive effects of garlic on diabetes complications are discussed in this review. The role of garlic as both an insulin secretagogue and as an insulin sensitizer is reviewed. Evidence suggests that garlic’s antioxidative, antiinflammatory, and antiglycative properties are responsible for garlic’s role in preventing diabetes progression and the development of diabetes-related complications. Large-scale clinical studies with diabetic patients are warranted to confirm the usefulness of garlic in the treatment and prevention of diabetes.

4.1 Garlic prevents hypertension induced by chronic inhibition of nitric oxide synthesis. El ajo previene la hipertensión por una inhibición crónica de la síntesis del óxido nítrico.Pedraza-Chaverri-J; Tapia-E; Medina-Campos-ON; Angeles-Granados-M-de-los; Franco-M;
Department of Biology, Faculty of Chemistry, National Autonomous University of Mexico, 04510 D.F., Mexico.
Life-Sciences. 1998, 62: 6, PL71-PL77; 20 ref.: 1998
Garlic (Allium sativum) has been reported to activate nitric oxide synthase in vitro. Chronic inhibition of nitric oxide (NO) synthesis by Nomega-nitro-L-arginine-methyl-ester (L-NAME) induces arterial hypertension in rats. The effect of oral administration of L-NAME for 4 weeks on control and garlic-fed rats was studied.
Basal systolic blood pressure was recorded 4 weeks after garlic supplementation, and on weeks 1, 2, 3 and 4 after L-NAME  treatment. At the end of the study, the in vivo NO production was evaluated indirectly by measuring the urinary excretion of the stable end products of NO metabolism, nitrite (NO2) and nitrate (NO3). L-NAME induced arterial hypertension on weeks 1-4 in control rats but not in garlic-fed rats, whose blood pressure remained essentially the same as the basal values. Also, during this time period, blood pressure remained unchanged in garlic-fed rats without L-NAME treatment. Urinary excretion of NO2-/NO3- decreased in L-NAME-treated rats, increased in garlic-fed rats, and remained unchanged in garlic-fed rats treated with L-NAME. It is concluded that garlic blocks the L-NAME-induced hypertension by antagonizing in vivo the inhibitory effect of L-NAME on NO production.

4.2 Gender- and age-related variations in blood viscosity in normal volunteers: a study of the effects of extract of Allium sativum and Ginkgo biloba.

Phytomedicine. 2007 Aug;14(7-8):447-51. Epub 2007 JulGalduróz JC, Antunes HK, Santos RF.
Departamento de Psicobiologia, Universidade Federal de São Paulo, Brazil. galduroz@psicobio.epm.br
This study sought to compare the effects of age and gender on blood viscosity and to appraise the effectiveness of Ginkgo biloba and Allium sativum extracts in reducing blood viscosity.
Stage 1: Our sample consisted of 80 male volunteers (40 aged 18-60 and >40 aged 61 and over) and 80 females with the same age profile.
Stage 2: We studied 60 male volunteers allocated in groups: placebo, G. biloba, and A. sativum.
Stage 3: We studied 25 male volunteers and in the initial, intermediate, and final evaluations, the measures of blood viscosity were repeated.
Volunteers were given a clinical evaluation and submitted to laboratory tests. G. biloba led to the highest reduction in blood viscosity compared with placebo and A. sativum. In relation to the use of the two substances, G. biloba and A. sativum, dry extract of G. biloba proved to be more effective in reducing blood viscosity.

4.2 Freshly Crushed Garlic is a Superior Cardioprotective Agent than Processed Garlic. El ajo fresco desmenuzado es un protector vascular superior al ajo procesado.
Subhendu Mukherjee, Istvan Lekli, Shyamal Goswami and Dipak K. Das
Cardiovascular Research Center, University of Connecticut School of Medicine, Farmington, Connecticut 06030-1110
J. Agric. Food Chem., July 17, 2009
Abstract
In this study, we compared the cardioprotective effects of freshly crushed garlic vis–vis that of processed garlic. Twogroups of rats were gavaged with respective garlic preparations while the control group received vehicle only. After 30 days, all of the rats were sacrificed and isolated the hearts were subjected to 30 min ischemia followed by 2 h of reperfusion. Both of the garlic preparations provided cardioprotection, but superiorcardiac performance was noticed for those fed with freshly crushed garlic. Consistent with these results, the freshly crushed garlic group displayed significantly greater phosphorylation of antiapoptotic ERK1/2 proteins, reduced Bax/Bcl-2 ratio, and reduced phosphorylation of proapoptotic p-38MAPK and JNK. Moreover, the survival signaling network consisting of Akt-FoxO1 was increased in the freshly crushed garlic treated hearts. Freshly crushed garlic, but not the processed garlic, showed enhanced redox signaling as evident by increased level of p65 subunit of NF?B, Nrf2, and enhanced GLUT 4, PPARa, and PPARd. The results thus show that although both freshly crushed garlicand processed garlic provide cardioprotection, the former has additional cardioprotective properties presumably due to the presence of H2S.

5.1 Biological properties of garlic and garlic-derived organosulfur compounds. Propiedades biológicas del ajo y de sus compuestos organosulfurados. Particular atención a sus propiedades anticancerígenas.
Iciek M, Kwiecien I, Wlodek L.
Chair of Medical Biochemistry, Jagiellonian University, Medical College, Kraków, Poland.
Environ Mol Mutagen. 2009 Apr;50(3):247-65.
Medicinal properties of garlic (Allium sativum) have been widely known and used since ancient times till the present. Garlic enhances immune functions and has antibacterial, antifungal and antivirus activities. It is known to prevent platelet aggregation, and to have hypotensive and cholesterol- and triglyceride-lowering properties, although the latter features have been questioned. This review is focused on anticancer efficacy of Allium sativum, and attempts to explain the mechanisms of this action. Medicinal properties of garlic rely upon organosulfur compounds mostly derived from alliin. Organosulfur compounds originating from garlic inhibit carcinogen activation, boost phase 2 detoxifying processes, cause cell cycle arrest mostly in G2/M phase, stimulate the mitochondrial apoptotic pathway, increase acetylation of histones. Garlic-derived sulfur compounds influence also gap-junctional intercellular communication and participate in the development of multidrug resistance. This review presents also other little known aspects of molecular action of garlic-derived compounds, like modulation of cellular redox state, involvement in signal transduction and post-translational modification of proteins by sulfane sulfur or by formation of mixed disulfides (S-thiolation reactions).

5.2 Apoptosis induction in human lung adenocarcinoma cells by oil-soluble allyl sulfides: triggers, pathways, and modulators.

Wu XJ, Hu Y, Lamy E, Mersch-Sundermann V.
University Medical Center Freiburg, Institute of Environmental Medicine and Hospital Hygiene, Freiburg, Germany. ooxwu@hotmail.com
Environ Mol Mutagen. 2009 Apr;50(3):266-75
DAS (diallyl sulfide), DADS (diallyl disulfide), and DATS (diallyl trisulfide) are major oil-soluble allyl sulfides (OAS) that represent major garlic constituents. The anticarcinogenic and antimutagenic effects of these substances have been extensively studied during the last decades. Previous reports suggest that induction of apoptosis by OASs might contribute to their chemopreventive effects. In this study, we report that OASs DADS and DATS induce significant apoptosis in human lung adenocarcinoma A549 cells, whereas DAS does not. Differential modulation of reactive oxygen intermediates (ROI) and mitochondria membrane potential (MMP) may account for the apoptotic effects of DADS and DATS. The underlying molecular mechanisms of apoptosis induction by both compounds include activation of C-Jun N-terminal kinase (JNK), up-regulation of p53, and down-regulation of bcl-2 expression. In our test series, up-regulation of extracellular signal-regulated protein kinase (ERK) was dispensable for apoptosis induction; DAS, DADS, or DATS did not modify expression of MAPK p38, bax, and bcl-xL. Further investigation revealed that the specific JNK inhibitor SP600125 and the antioxidant NAC blocked DADS and DATS-induced apoptosis, whereas ERK inhibitors did not. Additionally, our data provide the first evidence that Fas-mediated cell death pathway is partly involved in DADS but not DATS-mediated cell death. Taken together, our work has elucidated the triggers, important modulators, and signal transduction pathways in DADS and DATS-mediated apoptosis.