garlic
High-performance ion-pair chromatography method for simultaneous analysis of alliin, deoxyalliin, allicin and dipeptide precursors in garlic products using multiple mass spectrometry and UV detection.

Arnault I, Christides JP, Mandon N, Haffner T, Kahane R, Auger J.

Universite Francois Rabelais, IRBI, CNRS UMR 6035, Parc de Grandmont, 37200 Tours France.

The quality of garlic and garlic products is usually related to their alliin content and allicin release potential. Until now no analytical method was able to quantify simultaneously allicin, its direct precursor alliin (S-allyl-L-cysteine sulfoxide), SAC (S-allyl-L-cysteine) as well as various dipeptides that apparently serve as storage compounds in garlic. It is well known that all these intermediates are involved in the allicin biosynthetic pathway. A simple and rapid HPLC method suitable for routine analysis was developed using eluents containing an ion-pairing reagent. Particularly, heptanesulfonate as ion-pairing reagent guarantees a sufficient separation between alliin and the more retained dipeptides at very low pH. Allicin was eluted after 18 min on a 150 x 3 mm column. Synthetic reference compounds were characterized by the same chromatographic method using a diode-array UV detector and an ion trap mass spectrometer (electrospray ionization) in the multiple MS mode. In routine analysis of garlic bulbs, powders and other products, the diode-array detector is sufficient for a relevant quantification. Our method has been used in studies to improve the quality of garlic and its derived products.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12703902&dopt=Abstract garlic



garlic
Sensitivity of food pathogens to garlic (Allium sativum).

Kumar M, Berwal JS.

Department of Animal Products Technology, CCS Haryana Agricultural University, Hisar, India.

The inhibitory activity of garlic (Allium sativum) against Staphylococcus aureus, Salmonella typhi, Escherichia coli and Listeria monocytogenes was measured by the 'turbidity' method. Minimum inhibitory concentration (MIC) of garlic at 80% inhibition level was calculated for these bacteria. All bacterial pathogenic strains tested were inhibited by garlic; E. coli was most sensitive and Listeria monocytogenes was least sensitive. Therefore, garlic has potential for the preservation of processed foods.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9633635&dopt=Abstract garlic



garlic
Effects of feeding fresh garlic and garlic oil on detoxifying enzymes and micronuclei formation in rats treated with azoxymethane.

Khanum F, Anilakumar KR, Sudarshanakrishna KR, Viswanathan KR.

Biochemistry & Nutrition Discipline Defence Food Research Laboratory, Mysore, India.

The effect of feeding a fresh garlic or garlic oil-supplemented diet was studied in rats for a period of 23 weeks with or without the treatment of a carcinogen azoxymethane (AOM), on the modulation of detoxification enzymes and micronuclei formation. The results showed that feeding fresh garlic or garlic oil-supplemented diets tended to reduce hepatic lipid peroxidation, though not to significant levels. Glutathione content was also not altered. The catalase activity in liver of rats fed a fresh garlic-supplemented diet was reduced compared to that of the control diet; however, the activity was not affected by AOM treatment. Ingestion of garlic caused a 40 percent increase in the hepatic glutathione peroxidase activity, whereas carcinogen treatment reduced it. The activity of hepatic glutathione-S-transferase was unaffected by the feeding regimen, while it was lowered in the garlic oil diet group treated with AOM. The gamma glutamyl transpeptidase activity was elevated more than sevenfold, in the kidney of rats treated with AOM, while it was reduced almost to half when the AOM-treated rats were fed fresh garlic or garlic oil. Micronuclei formation was increased fourfold, in rats exposed to AOM whereas the increase was reduced to half when AOM-injected groups had either fresh garlic or garlic oil in their diet. From these studies, it is concluded that long-term feeding of garlic, fresh or oil, reduced the toxic effect of AOM in rats.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9637953&dopt=Abstract garlic



garlic
Attenuation of iron-nitrilotriacetate (Fe-NTA)-mediated renal oxidative stress, toxicity and hyperproliferative response by the prophylactic treatment of rats with garlic oil.

Iqbal M, Athar M.

Department of Medical Elementology and Toxicology, Faculty of Science, Jamia Hamdard (Hamdard University), New Delhi, India.

Iron nitrilotriacetate (Fe-NTA) is a potent nephrotoxic agent. In this communication we show that Fe-NTA-mediated nephrotoxicity is diminished by 1 wk of oral daily pretreatment of male albino Wistar rats with garlic oil given by gavage at 50 or 100 mg/kg body weight/ml corn oil. Intraperitoneal Fe-NTA treatment at a dose level of 9 mg Fe/kg body weight/10 ml enhances renal microsomal lipid peroxidation and hydrogen peroxide generation which are accompanied by a decrease in the activities of renal antioxidant enzymes (e.g. catalase, glutathione peroxidase, glutathione reductase and glutathione S-transferase), and a depletion in the level of renal glutathione. Parallel to these changes, a sharp increase in blood urea nitrogen and serum creatinine has been observed. In addition, Fe-NTA treatment also enhances renal ornithine decarboxylase (ODC) activity and increases [3H]thymidine incorporation into renal DNA. Prophylactic treatment of animals with garlic oil before the administration of Fe-NTA resulted in the diminution of Fe-NTA mediated injury. The enhancement of renal lipid peroxidation and hydrogen peroxide generation was decreased. In addition, there was recovery of glutathione depletion and inhibition of the activities of antioxidant enzymes. Similarly, in animals given the higher dose of garlic oil (100 mg/kg body weight) the enhanced blood urea nitrogen and serum creatinine levels, which are indicative of renal injury, showed a reduction of about 30% and 40%, respectively, in comparison with the group treated with Fe-NTA alone. Pretreatment with garlic oil also ameliorated the Fe-NTA-mediated induction of ODC activity and enhancement of [3H]thymidine incorporation into DNA in a dose-dependent manner. Our data suggest that garlic oil is a potent chemopreventive agent and may suppress Fe-NTA-induced nephrotoxicity.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9674956&dopt=Abstract garlic



garlic
Garlic prevents hypoxic pulmonary hypertension in rats.

Fallon MB, Abrams GA, Abdel-Razek TT, Dai J, Chen SJ, Chen YF, Luo B, Oparil S, Ku DD.

Liver Center, University of Alabama at Birmingham, Birmingham, Alabama 35294-0007, USA.

Hypoxic pulmonary vasoconstriction underlies the development of high-altitude pulmonary edema. Anecdotal observations suggest a beneficial effect of garlic in preventing high-altitude symptoms. To determine whether garlic influences pulmonary vasoconstriction, we assessed the effect of garlic on pulmonary pressures in rats subjected to alveolar hypoxia and on vasoconstriction in isolated pulmonary arterial rings. Garlic gavage (100 mg/kg body wt) for 5 days resulted in complete inhibition of acute hypoxic pulmonary vasoconstriction compared with the control group. No difference in mean arterial pressure or heart rate response to hypoxia was seen between the groups. Garlic solution resulted in a significant dose-dependent vasorelaxation in both endothelium-intact and mechanically endothelium-disrupted pulmonary arterial rings. The administration of NG-nitro-L-arginine methyl ester (a nitric oxide synthase inhibitor) inhibited the vasodilatory effect of garlic by 80%. These studies document that garlic blocks hypoxic pulmonary hypertension in vivo and demonstrate a combination of endothelium-dependent and -independent mechanisms for the effect in pulmonary arterial rings.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9700088&dopt=Abstract garlic