garlic
Effects of garlic preparations on the gastrointestinal mucosa.

Hoshino T, Kashimoto N, Kasuga S.

1st Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki 216-0015, Japan.

The effects of garlic preparations, including dehydrated raw garlic powder (RGP), dehydrated boiled garlic powder (BGP) and aged garlic extract (AGE), on the gastric mucosa were determined using a newly established endoscopic air-powder delivery system, which can deliver solid materials directly into the stomach. Among the three preparations, RGP caused severe damage, including erosion. BGP also caused reddening of the mucosa, whereas AGE did not cause any undesirable effects. The safety of enteric-coated garlic products was also determined. Direct administration of pulverized enteric-coated products on the gastric mucosa caused reddening of the mucosa. When an enteric-coated tablet was administered orally, it caused loss of epithelial cells at the top of crypts in the ileum. These results suggest that caution be used with regard to safety and effectiveness when choosing a garlic preparation because some preparations may have undesirable effects, including gastrointestinal problems.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11238827&dopt=Abstract garlic



garlic
Allicin release under simulated gastrointestinal conditions from garlic powder tablets employed in clinical trials on serum cholesterol.

Lawson LD, Wang ZJ, Papadimitriou D.

Research Department, Murdock Madaus Schwabe, Inc., Springville, Utah, USA. LLawson23 aol.com

The failure of five recent clinical trials to show significant reduction in elevated serum cholesterol by a single brand of allicin-standardized garlic powder tablets is in contrast to many prior positive studies with the same brand. The hypocholesterolemic activity of garlic is mainly due to allicin, a compound that is produced by the acid-sensitive garlic enzyme, alliinase, only after tablet consumption. Therefore, the allicin-releasing ability of ten lots of these tablets--manufactured over the same years that the positive and negative clinical trials were conducted (1989-1997)--was determined under simulated gastrointestinal dissolution conditions, as defined by U.S. Pharmacopeia Method 724A. It was found that the older lots were more resistant to acid-disintegration (2.5 h vs. 1.3 h, P < 0.001) and that they released three times as much allicin (44% vs. 15 % of their potential, P < 0.001) as the newer lots. A second brand of tablets employed in a recent negative trial released no detectable amount of allicin, while a third set of tablets with high allicin release was used in a trial that gave positive effects. Hence, the persons involved in the recent negative clinical trials probably received considerably less allicin than did those in the older positive studies, possibly accounting for much of the discrepancy in the outcomes. In conclusion, clinical trials using garlic powder tablets to assess any effect of garlic that might be related to allicin, as most are, cannot be considered valid for garlic when the trial shows no effect, unless the expected allicin release from the tablets has at least been determined under standardized drug release conditions (USP 724A).

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11270714&dopt=Abstract garlic



garlic
Novel quantitative assays for estimating the antimicrobial activity of fresh garlic juice.

Unal R, Fleming HP, McFeeters RF, Thompson RL, Breidt F Jr, Giesbrecht FG.

US Department of Agriculture, Agricultural Research Service, Raleigh, North Carolina 27695-7624, USA.

Novel agar diffusion and broth dilution assays were developed for quantitatively estimating the antimicrobial activity of fresh garlic juice. Bacteria found to be inhibited by garlic juice in agar diffusion assay included two gram-positive and five gram-negative species. Leuconostoc mesenteroides was not inhibited. Escherichia coli B-103 (HB101, with pJH101, ampicillin resistant, 100 microg ml(-1)) was inhibited and chosen as the standard culture for quantitative assays. The agar diffusion assay was based on the slope ratio method, where the slope of dose response for garlic juice was divided by the slope of dose response for methylmethane thiosulfonate (MMTSO2). Juice from fresh garlic varied in activity between 1.76 and 2.31 microg of MMTSO2 per mg of garlic juice. The activity of juice decreased during 11 months of storage of garlic cloves at 5 degrees C from 2.31 to less than 0.1 microg of MMTSO2 per mg of juice. The broth dilution assay also used the E. coli B-103 culture, which permitted selective enumeration of this bacterium when 100 microg ml(-1) of ampicillin was incorporated into the enumerating agar. Selective enumeration was essential since the garlic juice was not sterile and, thus, contained natural flora. Growth of E. coli was unaffected by 0.1%, delayed by 0.25%, and completely inhibited at 0.5 and 2% garlic juice in broth during 24 h of incubation at 37 micro C. The minimum inhibition concentration of garlic juice by broth dilution assay was, thus, estimated to be 0.5%, which is equivalent to 3.46 microg of MMTSO2 per mg of garlic juice by the agar diffusion assay.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11271766&dopt=Abstract garlic



garlic
Differential regulation of NO availability from macrophages and endothelial cells by the garlic component S-allyl cysteine.

Kim KM, Chun SB, Koo MS, Choi WJ, Kim TW, Kwon YG, Chung HT, Billiar TR, Kim YM.

Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chunchon, Kangwon-do, South Korea.

Garlic has been used as a traditional medicine for prevention and treatment of cardiovascular diseases. However, the molecular mechanism of garlic's pharmacological action has not been clearly elucidated. We examined here the effect of garlic extract and its major component, S-allyl cysteine (SAC), on nitric oxide (NO) production by macrophages and endothelial cells. The present study demonstrates that these reagents inhibited NO production through the suppression of iNOS mRNA and protein expression in the murine macrophage cell line RAW264.7, which had been stimulated with LPS and IFNgamma. The garlic extract also inhibited NO production in peritoneal macrophages, rat hepatocytes, and rat aortic smooth muscle cells stimulated with LPS plus cytokines, but it did not inhibit NO production in iNOS-transfected AKN-1 cells or iNOS enzyme activity. These reagents suppressed NF-kappaB activation and murine iNOS promoter activity in LPS and IFNgamma-stimulated RAW264.7 cells. In contrast, these reagents significantly increased cGMP production by eNOS in HUVEC without changes in activity, protein levels, and cellular distribution of eNOS. Finally, garlic extract and SAC both suppressed the production of hydroxyl radical, confirming their antioxidant activity. These data demonstrate that garlic extract and SAC, due to their antioxidant activity, differentially regulate NO production by inhibiting iNOS expression in macrophages while increasing NO in endothelial cells. Thus, this selective regulation may contribute to the anti-inflammatory effect and prevention of atherosclerosis by these reagents.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11275474&dopt=Abstract garlic



garlic
Use of alternative medicines in a multi-ethnic population.

Cappuccio FP, Duneclift SM, Atkinson RW, Cook DG.

Department of General Practice & Primary Care, St. George's Hospital Medical School, London, UK. f.cappuccio sghms.ac.uk

BACKGROUND: The prevalence and cost of regular use of non-prescribed alternative medicines are rising around the world, yet, little evidence is available that demonstrates the safety, efficacy, or effectiveness of specific alternative medicine interventions. It is of interest to understand how and why these practices have become so popular in different societies with different health care organizations and provisions, and which factors predict the regular use of alternative medicines. METHODS: We assessed the prevalence and the predictors of regular use of non-prescribed vitamin supplements, cod liver oil, primrose oil, and garlic in a cross-sectional population-based study in South London of 1,577 men and women, aged 40-59 years (883 women, 523 White, 549 of African origin and 505 of South Asian origin), when allowing for potential confounders. RESULTS: The prevalence of regular users of alternative medicines was 10.4% (164/1,577); 7.4% (116) made regular use of non-prescribed vitamin supplements, whereas 5.3% (84) used either cod liver oil, primrose oil, or garlic preparations. When adjusted for age, ethnicity and social class, women were more likely than men to use at least one alternative medicine (OR 2.09 [95% CI 1.45-3.00]). This was true both for vitamin supplements (1.98 [1.29-3.03]) and for oil or garlic supplements (1.91 [1.17-3.14]). The use of oil or garlic (P<.005) but not vitamin supplements (P=.32) varied by ethnic group. In particular, Black people of African origin were more likely to use alternative medicines than either Whites (1.78 [1.07-2.94]) or South Asians (1.66 [1.07-2.59]), the least common users. People in social classes IV and V were less likely to use alternative medicines (0.53 [0.31-0.90]) than those in social classes I and II, though this was due more to lesser use of non-prescribed vitamin supplements than of cod liver oil, primrose oil or garlic. These associations were not attenuated by further adjustment for body mass index, smoking, marital status and age at leaving full-time education. CONCLUSIONS: The regular users of alternative medicines in London are more likely to be women, of African origin, and of higher socioeconomic status. Given the lack of evidence of efficacy and safety of these alternative medicines, it is important to understand the cultural differences in values and beliefs about traditional medicine that may underlie these findings.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11289231&dopt=Abstract garlic