garlic
Garlic extracts stimulate proliferation of rat lymphocytes in vitro by increasing IL-2 and IL-4 production.

Colic M, Savic M.

Institute of Medical Research, Military Medical Academy, Belgrade, Yugoslavia.

Garlic components are known to modulate certain immune functions. However, mechanisms of their action are not sufficiently elucidated. This study was, therefore, undertaken to examine the effects of aqueous and ethanolic extracts prepared from a garlic powder sample on proliferation of rat spleen lymphocytes in culture. Cells were stimulated with the combination of phorbol myristate acetate (PMA) and a Ca ionophore (A23187) or R73 monoclonal antibody (mAb) directed to the alphabeta chain of T cell receptor. It has been shown that both extracts significantly stimulated proliferation of lymphocytes. The effect correlated with upregulation of the Interleukin 2 receptor alpha (IL-2R alpha) expression and the increase in IL-2 production. Stimulation of IL-2 production by the extracts was higher in cultures with PMA/Ca ionophore than in cultures with R73 mAb. In contrast, both extracts stimulated production of IL-4 by splenocytes triggered by R73 mAb. The complete dependence of lymphocyte proliferation in cultures with R73 mAb and garlic extracts on IL-2 and IL-4 was demonstrated using neutralising mAbs to IL-2R alpha and IL-4. These results suggest that the potentiating effect of garlic extracts on lymphocyte proliferation in vitro differs depending on specific stimulators of cell proliferation and probably on the type of responding cells.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10737264&dopt=Abstract garlic



garlic
Activities of garlic oil, garlic powder, and their diallyl constituents against Helicobacter pylori.

O'Gara EA, Hill DJ, Maslin DJ.

School of Health Sciences, University of Wolverhampton, Wolverhampton WV1 1DJ, United Kingdom.

Chronic Helicobacter pylori disease is reduced with Allium vegetable intake. This study was designed to assess the in vivo anti-H. pylori potential of a variety of garlic substances. The garlic materials all showed substantial but widely differing anti-H. pylori effects against all strains and isolates tested. The MICs (range, 8 to 32 microg/ml) and minimum bactericidal concentrations (MBCs) (range, 16 to 32 microg/ml) of undiluted garlic oil (GO) were smaller than those of garlic powder (GP) (MIC range, 250 to 500 microg/ml; MBC range, 250 to 500 microg/ml) but greater than the MIC of allicin (4. 0 microg/ml) (Table 2) present in GP. Allicin (MIC, 6 microg/ml; MBC, 6 microg/ml) was more potent than diallyl disulfide (MIC range, 100 to 200 microg/ml; MBC range, 100 to 200 microg/ml), its corresponding sulfide, but of a strength similar to that of diallyl tetrasulfide (MIC range, 3 to 6 microg/ml; MBC range, 3 to 6 microg/ml). Antimicrobial activity of the diallyl sulfides increased with the number of sulfur atoms. Time course viability studies and microscopy showed dose-dependent anti-H. pylori effects with undiluted GO, GP, allicin, and diallyl trisulfide after a lag phase of ca. 1 to 2 h. Substantial in vitro anti-H. pylori effects of pure GO and GP and their diallyl sulfur components exist, suggesting their potential for in vivo clinical use against H. pylori infections.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10788416&dopt=Abstract garlic



garlic
Protection by garlic against adriamycin induced alterations in the oxido-reductive status of mouse red blood cells.

Thabrew MI, Samarawickrema NA, Chandrasena LG, Jayasekera S.

Department of Biochemistry and Clinical Chemistry, Faculty of Medicine, University of Kelaniya, Talagolla Road, Ragama, Sri-Lanka.

The effects of oral garlic supplementation on the activities of (a) the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX) and (b) lipid peroxidation, as assessed by malondialdehyde (MDA) production in red blood cells of normal mice and those subject to oxidative stress by chronic administration of the anti-tumour drug adriamycin has been investigated. As expected, adria-mycin administration resulted in a significant increase in MDA generation (by 105.4%) and a decrease in GPX activity (by 23.8%) in the red blood cells. Although garlic had no significant effects on the basal levels of the antioxidant enzymes or MDA generation in red blood cells of normal mice (untreated with adriamycin), at doses of 20 mg/kg or 100 mg/kg, garlic was able to decrease significantly the adriamycin induced changes in the oxido-reductive status of the red blood cells. Thus, on administration of adriamycin to mice fed diets containing 20 mg/kg or 100 mg/kg garlic, the drug-induced increase in MDA generation was 38.2% and 22.5% respectively, less than that produced by adriamycin in mice fed normal diets, containing no garlic (105.4%). Similarly, in mice fed diets providing 20 mg/kg and 100 mg/kg garlic, adriamycin was able to decrease GPX activity by only 15.1% and 7.6% respectively, less than that produced by adriamycin in rats fed normal diets, containing no garlic (23.9%). Copyright 2000 John Wiley & Sons, Ltd.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10815020&dopt=Abstract garlic



garlic
Effect of allicin from garlic powder on serum lipids and blood pressure in rats fed with a high cholesterol diet.

Ali M, Al-Qattan KK, Al-Enezi F, Khanafer RM, Mustafa T.

Department of Biological Sciences, Faculty of Science, Kuwait University, Safat. muslim kuc01.kuniv.edu.kw

The use of fresh aqueous garlic extract is known to be effective in reducing thromboxane formation by platelets in both in vivo and in vitro animal models of thrombosis. In the present study, we studied the effect of Lichtwer garlic powder (containing 1.3% alliin equivalent to 0.6% allicin) on the serum cholesterol, triglyceride, glucose, protein, and systolic blood pressure in rats fed with a high cholesterol diet. Experimental rats were fed a 2% high cholesterol diet with and without garlic powder for 6 weeks. Control rats were fed a normal diet. The aqueous garlic powder extract was given orally to rats on a daily basis. It was observed that cholesterol-fed animals had a significant increase in serum cholesterol compared to the control group of rats fed on a normal diet. However, when the rats were fed with a high cholesterol diet mixed with garlic powder, there was a significant reduction in their serum cholesterol levels compared with the group which were on a diet containing high cholesterol without garlic powder. Serum triglyceride levels were also significantly lowered by garlic powder when compared to control and high cholesterol diet group rats. The blood pressure of the high cholesterol diet animals was significantly higher compared to the animals receiving the control diet. The blood pressure of the animals receiving garlic powder and high cholesterol diet was significantly lower as compared to the high cholesterol and control diet group. No significant changes were observed in the serum glucose and protein in all of the rats. These results show that garlic is beneficial in reducing blood cholesterol, triglycerides levels and systolic blood pressure in hypercholesterolemic rats. Our experimental results show that garlic may beneficially affect two risk factors for atherosclerosis--hyperlipidemia and hypertension.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10882191&dopt=Abstract garlic



garlic
Chemical speciation influences comparative activity of selenium-enriched garlic and yeast in mammary cancer prevention.

Ip C, Birringer M, Block E, Kotrebai M, Tyson JF, Uden PC, Lisk DJ.

Department of Experimental Pathology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA. Clement.Ip roswellpark.org

A recent human intervention trial showed that daily supplementation with selenized yeast (Se-yeast) led to a decrease in the overall cancer morbidity and mortality by nearly 50%; past research has also demonstrated that selenized garlic (Se-garlic) is very effective in mammary cancer chemoprevention in the rat model. The goal of this study was to compare certain biological activities of Se-garlic and Se-yeast and to elucidate the differences based on the chemical forms of selenium found in these two natural products. Characterization of organic selenium compounds in yeast (1922 microg/g Se) and garlic (296 microg/g Se) was carried out by high-performance liquid chromatography with inductively coupled plasma mass spectrometry or with electrospray mass spectrometry. Analytical speciation studies showed that the bulk of the selenium in Se-garlic and Se-yeast is in the form of gamma-glutamyl-Se-methylselenocysteine (73%) and selenomethionine (85%), respectively. The above methodology has the sensitivity and capability to account for >90% of total selenium. In the rat feeding studies, supplementation of Se-garlic in the diet at different levels consistently caused a lower total tissue selenium accumulation when compared to Se-yeast. On the other hand, Se-garlic was significantly more effective in suppressing the development of premalignant lesions and the formation of adenocarcinomas in the mammary gland of carcinogen-treated rats. Given the present finding on the identity of selenomethionine and gamma-glutamyl-Se-methylselenocysteine as the major form of selenium in Se-yeast and Se-garlic, respectively, the metabolism of these two compounds is discussed in an attempt to elucidate how their disposition in tissues might account for the differences in cancer chemopreventive activity.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10888499&dopt=Abstract garlic