Uptake and accumulation and oxidative stress in garlic (Allium sativum L.) under lead phytotoxicity

The effects of different concentrations of Pb on growth of Allium sativum L, Pb uptake and accumulation, antioxidant enzyme activity and malondialdehyde content were investigated. The results indicated that shoot growth at high concentration of Pb (10⁻³ M) and roots growth at 10⁻³ M and 10⁻⁴ M Pb were significantly inhibited. Lead ions were accumulated mainly in the roots and only small amounts were translocated to bulbs and shoots. SOD activities in shoot and roots exposed to 10⁻³ M Pb were observed to be high. Plants exposed to 10⁻³ M Pb showed a significant increase in POD activity in roots versus the control and other Pb treatments. In roots, CAT activity and MDA concentration at 10⁻³ M Pb is high significantly. The mechanisms of Pb toxicity and tolerance in garlic are briefly discussed.     

The bioactivity of processed garlic (Allium sativum L.) as shown in vitro and in vivo studies on rats.

Garlic (Allium sativum L.) is widely used as an obligatory part in many cooked dishes loosing during this process a certain part of its bioactivity. Antioxidant capacity measured by the ferric-reducing/antioxidant power (FRAP) method and by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical assay was the highest in raw and in a short time processed garlic samples by cooking. 70 Wistar rats were randomly divided into 10 diet groups, each of seven. They were named Control, NPG, PG1, PG2, PG3, Chol, Chol/NPG, Chol/PG1, Chol/PG2 and Chol/PG3. The rats of the Control group were fed basal diet (BD), which included wheat starch, casein, soybean oil, cellulose, mineral and vitamin mixtures. To the BD of the nine other groups were added 25mg of lyophilized non processed garlic equivalent of 500 mg non processed garlic/kg body weight (NPG), the same quantity of processed garlic for 20, 40 and 60 min for PG1, PG2 and PG3, respectively, 1% of cholesterol (Chol), 1% of cholesterol and 25mg/kg body weight of lyophilized non processed garlic (Chol/NPG), 1% of cholesterol and the same quantity of processed garlic for 20, 40 and 60 min for Chol/PG1, Chol/PG2 and Chol/PG3, respectively. The dose of 500 mg (25mg of lyophilized garlic/kg body weight) was chosen as the most effective (Banerjee, S.K., Maulik, M., Mancahanda, S.C., Dinda, A.K., Gupta, S.K., Maulik, S.K., 2002. Dose-dependent induction of endogenous antioxidants in rat heart by chronic administration of garlic. Life Sciences 70, pp. 1509-1518). Plasma lipid profile and the total antioxidant capacity in rats significantly differed in diet groups with addition of garlic samples cooked for a long time. In summary, garlic cooked for a short time preserves a high bioactivity of non processed garlic. The diet supplemented with these samples and cholesterol improved lipid indices, decreased fibrinogen and increased antioxidant activity in plasma of rats. Therefore, for preservation of garlic bioactivity optimal regime has to be used.     

In vitro virucidal effects of Allium sativum (garlic) extract and compounds.

Garlic (Allium sativum) has been shown to have antiviral activity, but the compounds responsible have not been identified. Using direct pre-infection incubation assays, we determined the in vitro virucidal effects of fresh garlic extract, its polar fraction, and the following garlic associated compounds: diallyl thiosulfinate (allicin), allyl methyl thiosulfinate, methyl allyl thiosulfinate, ajoene, alliin, deoxyalliin, diallyl disulfide, and diallyl trisulfide. Activity was determined against selected viruses including, herpes simplex virus type 1, herpes simplex virus type 2, parainfluenza virus type 3, vaccinia virus, vesicular stomatitis virus, and human rhinovirus type 2. The order for virucidal activity generally was: ajoene > allicin > allyl methyl thiosulfinate > methyl allyl thiosulfinate. Ajoene was found in oil-macerates of garlic but not in fresh garlic extracts. No activity was found for the garlic polar fraction, alliin, deoxyalliin, diallyl disulfide, or diallyl trisulfide. Fresh garlic extract, in which thiosulfinates appeared to be the active components, was virucidal to each virus tested. The predominant thiosulfinate in fresh garlic extract was allicin. Lack of reduction in yields of infectious virus indicated undetectable levels of intracellular antiviral activity for either allicin or fresh garlic extract. Furthermore, concentrations that were virucidal were also toxic to HeLa and Vero cells. Virucidal assay results were not influenced by cytotoxicity since the compounds were diluted below toxic levels prior to assaying for infectious virus. These results indicate that virucidal activity and cytotoxicity may have depended upon the viral envelope and cell membrane, respectively. However, activity against non-enveloped virus may have been due to inhibition of viral adsorption or penetration.(ABSTRACT TRUNCATED AT 250 WORDS)     

An in vitro study of different extracts and fractions of Allium sativum (garlic): vascular reactivity

The aim of this study was to investigate the effect of different novel extracts and fractions obtained from Allium sativum (garlic) on in vitro vessel contraction in order to deepen our knowledge of their mechanism of action on vascular reactivity. The contraction induced by noradrenaline (NE, 10(-6) or 10(-5) M) or KCl (80 mM) was relaxed with all the extracts and fractions studied, but this effect was higher with RG 20-100 (raw garlic fraction) and FG 20-100 (frozen garlic fraction). To increase our understanding of the mechanisms of action of RG 200-100 and FG 200-100, we found their inhibitory actions were retained in the absence of endothelium, whereas inhibition of the entry of extracellular calcium and mobilization of intracellular calcium may play an instrumental role.     

Investigation on the antibacterial properties of garlic (Allium sativum) on pneumonia causing bacteria

The antibacterial activity of the crude aqueous extract of garlic was investigated against some pneumonia causing bacteria by an agar dilution technique. The results revealed that Streptococcus pneumoniae standard test organism was completely inhibited by 7.8 mg/ml of media and the clinical isolate of Klebsiella pneumoniae was completely inhibited by 24.38 mg/ml of media, indicating that Streptococcus pneumoniae is the most sensitive and Klebsiella pneumoniae the least. Garlic could be used as an effective antibacterial agent for these pathogenic microorganisms.     

Quality of herbal remedies from Allium sativum: differences between alliinase from garlic powder and fresh garlic

Alliinase (EC 4.4.1.4) has been isolated from commercially available garlic (Allium sativum L., Alliaceae) powder and was investigated with respect to its use as ingredient of herbal remedies. The enzyme was purified to apparent homogeneity and results were compared with those obtained from a sample of fresh A. sativum var. pekinense. The purification of the enzyme involved a gel filtration step as well as affinity chromatography on concanavalin-A agarose. Vmax using L-(+)-alliin as substrate (252 mumol min-1 mg-1) was at the lower range of data given in the literature (214-390 mumol min-1 mg-1). L-(-)-Alliin was also accepted as substrate (54 mumol min-1 mg-1). Vmax for alliinase from A. sativum var. pekinense was at 332 mumol min-1 mg-1 and 90 mumol min-1 mg-1 for L-(+)- and L-(-)-alliin, respectively. The Km values for alliinase from garlic powder were estimated to be 1.6 mM for L-(+)-alliin and 2.8 mM for L-(-)-alliin. In contrast to literature values, both temperature and pH optima were somewhat higher (36 degrees C and pH 7.0 versus 33 degrees C and pH 6.5, respectively). The enzyme was found to be active in a range from pH 5 to pH 10. Gel electrophoresis gave evidence that the alliinase obtained from garlic powder consisted of two slightly different subunits with molecular weights of 53 and 54 kDa whereas alliinase obtained from fresh garlic consists of two identical subunits. It is assumed that the alliinase gets significantly altered during the drying process of garlic powder but is still capable to convert alliin to allicin.     

Hexavalent chromium and its effect on health: possible protective role of garlic (Allium sativum Linn)

Hexavalent chromium or chromium (VI) is a powerful epithelial irritant and a confirmed human carcinogen. This heavy metal is toxic to many plants, aquatic animals, and bacteria. Chromium (VI) which consists of 10%-15% total chromium usage, is principally used for metal plating (H2Cr2O7), as dyes, paint pigments, and leather tanning, etc. Industrial production of chromium (II) and (III) compounds are also available but in small amounts as compared to chromium (VI). Chromium (VI) can act as an oxidant directly on the skin surface or it can be absorbed through the skin, especially if the skin surface is damaged. The prooxidative effects of chromium (VI) inhibit antioxidant enzymes and deplete intracellular glutathione in living systems and act as hematotoxic, immunotoxic, hepatotoxic, pulmonary toxic, and nephrotoxic agents. In this review, we particularly address the hexavalent chromium-induced generation of reactive oxygen species and increased lipid peroxidation in humans and animals, and the possible role of garlic (Allium sativum Linn) as a protective antioxidant.     

Pharmacodynamic interaction study of Allium sativum (garlic) with cilostazol in patients with type II diabetes mellitus

Aim:

Garlic is available as an over-the-counter herbal supplement and is known to have antiplatelet properties. Because of scarcity of clinical data regarding the safety of concomitant use of garlic supplements and anticoagulants, we tried to evaluate the effects of coadministration of single and multiple doses of garlic and cilostazol on platelet aggregation.

Materials and Methods:

The study was a randomized, open label, placebo-controlled, crossover study of type II diabetic patients, where 14 patients were enrolled and 10 completed the study. The patients were administered 600 mg aged garlic extract, 100 mg cilostazol, 600 mg aged garlic extract, and cilostazol or placebo for seven days as per prior randomization schedule. Blood samples for platelet aggregation and bleeding time and clotting time were collected before and 2, 4, and 6 hours after single-dose drug administration and after seven days of treatment.

Results:

After single- and multiple-dose administration of garlic, there was a significant inhibition of platelet aggregation at 2 hours, whereas with cilostazol, the inhibition was significant at all the three time points tested, with 4 hours showing maximum inhibition. Coadministration of garlic and cilostazol in single and multiple doses for seven days did not produce any significant change in the antiplatelet activity of the individual drugs.

Conclusions:

Coadministration of aged garlic extract and cilostazol did not enhance the antiplatelet activity compared with individual drugs. Large randomized trials are needed to further evaluate the possible interaction of garlic in higher doses and in combination with other antiplatelet activity drugs.     

Formation of allicin from dried garlic (Allium sativum): a simple HPTLC method for simultaneous determination of allicin and ajoene in dried garlic and garlic preparations.]

In garlic (Allium sativum L.) the enzyme alliin lyase catalyzes the cleavage of alliin into allicin which reacts further to furnish ajoene. A simultaneous determination of allicin and ajoene is introduced which, in contrast to the determination of alliin only, allows for the testing of the activity of alliin lyase. It can be demonstrated that at a pH value of less than 3 the enzyme produces only small amounts of allicin. For this reason preparations from garlic should be administered only as enteric-coated formulations.     

Toxic effects induced by the repeat administration of Allium sativum L.]

Female and male rats were given 300 and 600 mg/kg/24 h of a Garlic bulb aqueous extract for 21 days. The results showed that garlic extract causes toxic effects affecting weight growth, biologic parameters and histologic structures.     

Antioxidant role of oils isolated from garlic (Allium sativum Linn) and onion (Allium cepa Linn) on nicotine-induced lipid peroxidation.

Nicotine, a major component of tobacco, is partly responsible for the development of atherosclerosis. It has been suggested that antioxidant nutrients are protective against degenerative diseases. So we have studied the antioxidant effect of oils isolated from onion and garlic on nicotine-induced lipid peroxidation in rat tissues. The lipid peroxidation products and scavenging enzymes were assessed in liver, lungs, heart and kidney. The rats were treated with 0.6 mg nicotine/kg bw and simultaneously given 100 mg garlic or onion oils/kg bw for 21 d. Thiobarbituric acid reactive substances, conjugated dienes and hydroperoxides concentrations were significantly increased in the tissues of nicotine-treated rats. Both the garlic oil and onion oil supplementation to nicotine-treated rats increased resistance to lipid peroxidation. The activities of catalase, superoxide dismutase and glutathione peroxidase decreased in nicotine-treated rats, but there was a trend to increased glutathione content. With garlic oil or onion oil supplementation, nicotine-treated rats had increased activities of antioxidant enzymes and increased concentrations of glutathione. These results indicate that oils of garlic and onion are effective antioxidants against the oxidative damage caused by nicotine.     

Effect of garlic (Allium sativum) oil on exercise tolerance in patients with coronary artery disease

The effect of six weeks garlic oil administration was observed on cardiac performance and exercise tolerance in 30 patients of coronary artery disease. After initial treadmill stress test, they were administered garlic oil in the dose of four capsules twice a day for 6 weeks and treadmill stress test was repeated. Garlic significantly (P<0.01) reduced heart rate at peak exercise and also significantly reduced the work load upon the heart resulting in better exercise tolerance (P<0.05) as compared to the initial test. It appears to be a good adaptogen to be utilized in patients with coronary artery disease.     

Comparative study on the efficacy of Allium sativum (garlic) in reducing some heavy metal accumulation in liver of wistar rats

Scope

Heavy metals are known to cause damage through indirect oxidative effects. This study was undertaken to compare the therapeutic efficacy and protective ability of garlic extracts on reducing toxicity induced by mercury, lead and cadmium in the liver.

Methods and results

Rats were fed with rat chow mixed with raw garlic (7% w/w) while mercury (10 ppm), cadmium (200 ppm) and lead (100 ppm) were given in drinking water. Garlic was administered either at the same time with the metals (group 2), a week after exposure to heavy metals (group 3) or a week before heavy metal exposure (group 4) for 6 weeks. The heavy metal accumulations in the liver were determined using AAS. The percentage protection showed a time-dependent effect and was significantly (P < 0.01) higher for cadmium compared to mercury and lead-treated groups. Analysis between the groups showed that garlic treatment after exposure had a significantly (P < 0.05) higher percentage protection when compared with other modes.

Conclusion

These results suggest that garlic offered more hepatoprotective effect to cadmium followed by mercury and least protection to lead at the selected dose of each metal in this study through the processes of uptake, assimilation and elimination of these metals.     

Evaluation of the anthelmentic activity of garlic (Allium sativum) in mice naturally infected with Aspiculuris tetraptera

This study was performed to investigate the anthelmentic (nematodes) effect of garlic in Swiss albino mice naturally infected with Aspiculuris tetraptera. Natural infection was determined by the use of cellophane tape method on the perianal region and by the technique of centrifugal flotation of stool samples. The infected mice were divided into three groups; namely, Group 1: garlic treatment groups (n: 18), Group 2: positive control (treated with ivermectin, n: 19) and Group 3: untreated control group (n: 19). The mice in Group 1 were given orally freshly crushed garlic homogenates every day for 7 days. The animals in Group 2 were treated with ivermectin intramuscular at a dose of 0.2 mg/kg body weight. The mice in Group 3 received only serum physiologic orally. After 8 days of administrations, all mice were killed humanely using inhalation anaesthesia and then the parasites in the intestine were counted. It was observed that garlic and ivermectin were 91.24 % and 78.03 % effective against A. tetraptera in naturally infected mice, respectively. Results obtained from this study were compared statistically and differences were found to be significant (p<0.001). It was found that garlic was efficient along the duration of the treatment in mice. Garlic may be useful as an alternative treatment against nematode parasites in animals and human. This article includes a new research using Allium sativum anthelmentic effect on mouse and has been patented.     

An in vitro assessment of the antibacterial effect of garlic (Allium sativum) on bacterial isolates from wound infections

BACKGROUND: Garlic (Allium sativum) has come to be seen as an all rounded treatment for preventing wound infection, common cold, malaria, cough and lung tuberculosis, hypertension, sexually transmitted diseases, mental illness, kidney diseases, liver diseases, asthma, diabetes. OBJECTIVE: The main objective of this study was to assess the antibacterial effect of crude preparation of garlic on bacterial isolates from the wound infections. METHODS: An experimental study was conducted in Gondar University Teaching Hospital School of Medical Laboratory Technology, Microbiology Laboratory from June 2004 to April 2005 by agar dilution technique. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of garlic to control strains of Staphylococcus aureus ATTC 25923 and Escherichia coli ATTCC 25922, as well as to clinical isolates of S. aureus, E. coli, Proteus mirabilis, Klebsiella pneumoniae and Pseudomonas aeruginosa were determined using agar dilution method The data was collected in triplicate. RESULTS: All the tested organisms were inhibited by 33.75 mg/ml of the crude preparation of garlic except control organism and clinical isolates of S. aureus, which were inhibited by 11.25 mg/ml of crude garlic. Garlic did not reveal bactericidal effect up to a concentration of 37.5 mg/ml against all the tested organisms. CONCLUSION: Crude preparation of garlic could be used as an effective antibacterial agent for the tested organisms. Nevertheless, clinical trial on the effect of garlic is essential before advocating large-scale therapy.