garlic
Cell cycle arrest and differential gene expression in HT-29 cells exposed to an aqueous garlic extract.

Frantz DJ, Hughes BG, Nelson DR, Murray BK, Christensen MJ.

Department of Food Science and Nutrition, Brigham Young University, Provo, UT 84602, USA.

Epidemiological data show an inverse correlation between garlic consumption and the risk for colon cancer. To examine this relationship, HT-29 human adenocarcinoma cells were cultured in the presence and absence of an aqueous garlic extract. Garlic treatment resulted in a fraction of cells detaching from the culture flasks. These cells remained viable. Flow cell cytometry showed that untreated cells exhibited a normal distribution among phases of the cell cycle, with 12% of cells at the G2/M boundary. Of the garlic-treated cells remaining attached to the flask, 27% were present at the G2/M boundary. Treated cells that detached from the flask were found almost exclusively (89%) at the G2/M boundary. RNA fingerprinting and microarray analysis showed that expression of the gene for menin was twice as high in control cells as in detached treated cells. In contrast, expression of genes for epidermal growth factor receptor and integrin-alpha6 was nearly twice as high in detached treated cells as in control cells. These changes in gene expression were consistent with an arrest of the cell cycle at the G2/M boundary. Garlic's arrest of the cell cycle in human adenocarcinoma cells may explain in part its anticarcinogenic properties.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11525604&dopt=Abstract garlic



garlic
Carbon tetrachloride changes the activity of cytochrome P450 system in the liver of male rats: role of antioxidants.

Sheweita SA, El-Gabar MA, Bastawy M.

Department of Bioscience and Technology, Institute of Graduate Studies and Research, Alexandria University, 163 Horreya Ave., PO Box 832, Alexandria, Egypt. ssheweita yahoo.com

The cytochrome P-450 enzymes are responsible for the oxidation of xenobiotic chemicals including drugs, pesticides, and carcinogens. These enzymes include cytochrome P450, cytochrome b(5), arylhydrocarbon (benzo[a]pyrene) hydroxylase (AHH), NADPH-cytochrome C reductase and dimethylnitrosamine N-demethylase I (DMN-dI). Changes in the activities of the above mentioned enzymes were studied in the liver microsomes of rats treated with antioxidants (ascorbic acid (AA), DL-a-tocopherol (vitamin E, VE), garlic) as single- and repeated doses prior to the administration of a single dose of CCl(4). Pretreatment of rats with single doses of AA, VE, or garlic prior to the administration of CCl(4) was found to decrease the hepatic content of cytochrome P450, and the activities of DMN-dI and AHH. On the other hand, these treatments induced the hepatic content of cytochrome b(5) and the activity of NADPH-cytochrome c reductase. Pretreatment of rats with repeated doses of AA, VE, or garlic for 12 consecutive days prior to the administration of CCl(4) as single dose was potentially decreased the activities of cytochrome P450, DMN-dI and NADPH-cytochrome c reductase. Also, the activity of AHH decreased after treatments of rats with repeated doses of garlic prior to the administration of CCl(4). It was noted that repeated doses of antioxidants are more effective than single dose in decreasing the activity of drug-metabolizing enzymes. It is concluded that repeated doses of antioxidants or garlic could reduce the toxic effects exerted by CCl(4) upon the liver, and probably other organs, through inhibition of cytochrome P450 system that activates CCl(4) into its active metabolite, trichloromethyl radical. Moreover, inhibition of cytochrome P450 system could also reduce the toxic and carcinogenic effects of chemical carcinogens such as benzo(a)pyrene and dimethylnitrosamine. The mechanisms of antioxidant protection were discussed in the text.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11718950&dopt=Abstract garlic



garlic
Molecular characterisation of a complex mixture of viruses in garlic with mosaic symptoms in China.

Chen J, Chen J, Adams MJ.

Department of Biotechnology, College of Life Science, Zhejiang University, Hangzhou, China. jpchen mail.hz.zj.cn

Degenerate primers were used to detect and amplify cDNA of viruses of the genera Carlavirus, Allexivirus and Potyvirus from garlic plants with mosaic symptoms growing in Zhejiang province, China. Plants contained a complex mixture of viruses and strains. Three distinct stains of Garlic latent virus were detected; the most frequent one was completely sequenced and partial sequences were obtained for the other two. The complete sequence (8363 nt) was 76.4% identical to a Korean isolate. Two allexiviruses were detected and completely sequenced. One (8319 nt) was identified as Garlic virus X and comparisons showed that a published Korean isolate (which had 90.2% identical nucleotides) had an N-terminal deletion in the serine-rich ORF4. The other isolate (8451 nt), tentatively named Garlic virus E, appeared to be a new member of the genus. Phylogenetic analyses of the different viral proteins and distinctive conserved sequence motifs within the genus are discussed. This is the first report of allexiviruses from China. Using potyvirus primers, three distinct isolates of Onion yellow dwarf virus and one of Leek yellow stripe virus were detected and the 3'-terminal sequences of their genomes were determined. In a coat protein phylogenetic analysis, the new isolates were most closely related to other published isolates from Japan and China.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11722009&dopt=Abstract garlic



garlic
Effects of wild versus cultivated garlic on blood pressure and other parameters in hypertensive rats.

Mohamadi A, Jarrell ST, Shi SJ, Andrawis NS, Myers A, Clouatre D, Preuss HG.

Department of Medicine (Nephrology) and Pathology, Georgetown University Medical Center, 3900 Reservoir Road SE, Washington, DC 20007, USA.

Two separate studies were performed on hypertensive rats to assess the effects of wild, uncultivated garlic on elevated systolic blood pressure (SBP) and other cardiovascular parameters. Also, effects of wild garlic and cultivated garlic preparations were compared and the mechanisms behind pressure-lowering abilities of different garlic preparations were examined. The initial study determined that wild garlic lowers blood pressure. In the second study, cardiovascular effects of three different concentrations of wild garlic and two different cultivated garlics, i.e., a preparation low in allicin and one high in allicin, were compared. All three garlic preparations decreased SBP significantly. Wild garlic produced the greatest pressure-lowering effects, and the least pressure-lowering effects were seen with low-allicin garlic. Compared with control rats, circulating angiotensin II levels were significantly lower in all garlic-eating rats. Losartan decreased blood pressure significantly less and Nw-nitro-L arginine-methyl ester hydrochloride (LNAME) increased blood pressure significantly more in garlic-eating rats than in control rats, suggesting that the renin-angiotensin system (RAS) was less active and the nitric oxide system more active in garlic-consuming hypertensive rats. Accordingly, different garlic preparations, especially wild garlic, favorably influenced high SBP in hypertensive rats. These results suggest that both the RAS and the nitric oxide system are involved in the antihypertensive effects of garlic in hypertensive rats.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11728237&dopt=Abstract garlic



garlic
Death of Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes in garlic butter as affected by storage temperature.

Adler BB, Beuchat LR.

Center for Food Safety and Department of Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797, USA.

Garlic is known to have antimicrobial activity against several spoilage and pathogenic bacteria. However, the fate of Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes in garlic butter has not been reported. This study was undertaken to determine the viability of these organisms in garlic butter as affected by the type of raw minced garlic added to the butter, storage temperature, and storage time. Unsalted butter at 40 degrees C was combined with raw minced jumbo, elephant, or small-cloved garlic at a 4:1 butter/garlic ratio (wt/wt), inoculated with mixed-strain suspensions of Salmonella, E. coli O157:H7, or L monocytogenes, and stored at 4.4, 21, or 37 degrees C for up to 48 h. All pathogens retained their viability at 4.4 degrees C, regardless of the presence of garlic. The addition of garlic to butter enhanced the rates of inactivation of all three pathogens at 21 and 37 degrees C. The most rapid decline in pathogen populations was observed at 37 degrees C. The inactivation of L. monocytogenes occurred more slowly than did that of Salmonella or E. coli O157:H7. The inactivation of Salmonella and L. monocytogenes was more rapid in jumbo garlic butter than in elephant or small-cloved garlic butter. It is concluded that Salmonella, E. coli O157:H7, and L. monocytogenes did not grow in unsalted butter, with or without garlic added (20%, wt/wt), when inoculated products were stored at 4.4, 21, and 37 degrees C for up to 48 h.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12495019&dopt=Abstract garlic