garlic
In vivo radioprotection with garlic extract.

Singh SP, Abraham SK, Kesavan PC.

School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.

Garlic extract was evaluated in the mouse bone marrow micronucleus test for its possible protective effects against gamma-radiation-induced chromosomal damage. Together with this, biochemical assays were carried out to determine the changes in sulfhydryl content and glutathione S-transferase activities. Three doses of freshly prepared garlic extract (125, 250 and 500 mg/kg b.w.) were orally administered for 5 consecutive days, and the animals were irradiated 2 h after the final feeding. The results of the micronucleus test demonstrated that pre-treatment with garlic extract can lead to significant dose-related reductions in the frequencies of gamma-radiation-induced (2 Gy) micronucleated polychromatic erythrocytes. The anticlastogenic effect of garlic extract was observed against lower radiation doses of 0.5 and 1 Gy, but not 0.25 Gy. Significant increases in the sulfhydryl content and glutathione S-transferase activity were observed after either pre-treatment with garlic extract or irradiation. However, the irradiated garlic-extract pre-treated animals showed a significant reduction in sulfhydryl content and glutathione S-transferase activities.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8552136&dopt=Abstract garlic



garlic
Enhanced effectiveness of dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene dioxybiphenyl-2,2'-dicarboxylate in combination with garlic oil against experimental hepatic injury in rats and mice.

Kim SG, Nam SY, Chung HC, Hong SY, Jung KH.

College of Pharmacy, Duksung Women's University, Seoul, Korea.

The present study was designed to evaluate the effects of dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene dioxybiphenyl-2,2'-dicarboxylate (PMC) in combination with garlic oil against chemical-induced hepatic injury in rats and mice. Rats insulted with carbon tetrachloride were concomitantly treated with PMC and/or garlic oil (50 and 100 mg kg-1, respectively) for four weeks. Whereas treatment of animals with garlic oil alone was ineffective in suppressing carbon tetrachloride-induced hepatotoxicity, administration of PMC in combination with garlic oil more effectively protected the liver against the carbon tetrachloride-induced insult than PMC alone, as monitored by serum aminotransferase activity. Hepatoprotective effects of the formulation were further supported by the changes in the numbers of Kupffer cells and dead hepatocytes. Although prior treatment of rats with PMC for three days failed to protect hepatotoxicity elicited by allyl alcohol, the formulation of PMC and garlic oil was capable of blocking allyl alcohol-induced hepatotoxicity by approximately 40%. To further examine the effect of the agents on lipid metabolism in the liver, hepatic triglycerides and cholesterol contents were assessed in mice after a diet containing PMC and/or garlic oil for one week followed by a single dose of carbon tetrachloride. Garlic oil appeared to be more effective in bringing hepatic lipid levels to those of control than PMC alone. Treatment of animals with PMC in combination with garlic oil synergistically improved chemical-induced impairment of hepatic triglycerides and cholesterol.(ABSTRACT TRUNCATED AT 250 WORDS)

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8583372&dopt=Abstract garlic



garlic
[Studies on the stabilities of bioactive selenocompounds in selenium-enriched garlic and onion]

[Article in Chinese]

Yang W.

Institute of Nutrition and Food Hygiene, Chinese Academy of Preventive Medicine, Beijing 100050, China.

It is reported that selenium (Se) incorporation into garlic increases the bioactivities of garlic. Hence, the chemical changes of selenocompounds during processing and storage will influence the bioactive effectiveness of Se-enriched garlic. The principal selenocompounds in Se-enriched garlic are water-soluble, and several comparative experiments are thus conducted to examine the stabilities of the selenocompounds in water extracts of Se-enriched garlic and Se-enriched onion. The results show that preparing the garlic powder by freeze-drying technique can maintain the chemical properties of the selenium compounds in Se-enriched garlic. Se-methyl-selenocysteine is unstable in water extract of Se-enriched garlic when the extract is prepared and stored at room temperature. Specific alliinase inhibitor hydroxylamine (NHOH.HCl) effectively prevents the loss of Se-methyl-selenocysteine, which suggests that the decomposition of Se-methyl-selenocysteine may be catalyzed by alliinase. Se-methyl-selenocysteine is one of the main bioactive selenocompounds in Se-enriched garlic. The procedures of processing and storage should be carefully chosen to prevent the loss of selenocompounds and the decrease of the bioactivity of Se-enriched garlic. Se-enriched onion also contains alliinase and Se-methyl-selenocysteine, but its Se-methyl-selenocysteine is proved to be stable in the same water extract as that of Se-enriched garlic. The stability differences of Se-methyl-selenocysteine in Se-enriched garlic and onion, the mechanism of selenocompound decomposition and the bio-activities of decomposed compounds in Se-enriched garlic need to be further studied.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12600032&dopt=Abstract garlic



garlic
Evaluation of the modifying influence of arecanut on the garlic-modulated hepatic detoxication system enzymes, sulfhydryl content, and lipid peroxidation in mice.

Singh A, Rao AR.

Cancer Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.

This paper evaluates the potential effects of arecanut (Areca catechu, L.), an important ingredient of betel quid, on the garlic (Allium sativum, L.)-modulated activities of hepatic detoxication system enzymes, acid soluble sulfhydryl content, and lipid peroxidation in mice. Mice were fed on either a normal diet or a diet containing 0.25%, 0.5%, or 1% (w/w) arecanut for 45 days. During the last 10 days of treatment oral administration of garlic at the dose level of 20 or 100 mg/kg body weight/day was supplemented. Significant modulation in the activities of phase I and phase II enzymes, -SH content, and malondialdehyde (MDA) level by garlic was observed. Garlic-modulated alterations in glutathione S-transferase (GST) activity and -SH content were decreased, while cytochrome b5, cytochrome P-450, and MDA levels were further augmented by the arecanut plus garlic treatments.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8584984&dopt=Abstract garlic



garlic
Antioxidant activity of allicin, an active principle in garlic.

Prasad K, Laxdal VA, Yu M, Raney BL.

Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Canada.

Garlic has been claimed to be effective against diseases, in the pathophysiology of which oxygen free radicals (OFRs) have been implicated. Effectiveness of garlic could be due to its ability to scavenge OFRs. However, its antioxidant activity is not known. We investigated the ability of allicin (active ingredient of garlic) contained in the commercial preparation Garlicin to scavenge hydroxyl radicals (.OH) using high pressure liquid chromatographic (HPLC) method. .OH was generated by photolysis of H2O2 (1.25-10 mumoles/ml) with ultraviolet light and was trapped with salicylic acid which is hydroxylated to produce .OH adduct products 2,3- and 2,5-dihydroxybenzoic acid (DHBA). H2O2 produced a concentration-dependent .OH as estimated by .OH adduct products 2,3-DHBA and 2,5-DHBA. Allicin equivalent in Garlicin (1.8, 3.6, 7.2, 14.4, 21.6, 28.8 and 36 micrograms) produced concentration-dependent decreases in the formation of 2,3-DHBA and 2,5-DHBA. The inhibition of formation of 2,3-DHBA and 2,5-DHBA with 1.8 micrograms/ml was 32.36% and 43.2% respectively while with 36.0 micrograms/ml the inhibition was approximately 94.0% and 90.0% respectively. The decrease in .OH adduct products was due to scavenging of .OH and not by scavenging of formed .OH adduct products. Allicin prevented the lipid peroxidation of liver homogenate in a concentration-dependent manner. These results suggest that allicin scavenges .OH and Garlicin has antioxidant activity.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8594422&dopt=Abstract garlic