garlic
An evaluation of garlic and onion as antithrombotic agents.

Bordia T, Mohammed N, Thomson M, Ali M.

Department of Biochemistry, Faculty of Science, Kuwait University, 13060 Safat, Kuwait.

Garlic (Allium sativum) and onion (Allium cepa) have been evaluated as possible antithrombotic agents. Rats were given aqueous extracts of garlic and onion, orally or intraperitoneally, daily for a period of 4 weeks after which the rats were sacrificed. The blood was collected from the heart without anticoagulant and the serum was prepared. The level of thromboxane B2 (TXB2) in the serum was measured by radioimmunoassay. TXB2 levels in serum of rats treated with the low dose of aqueous extract of garlic (50 mg/kg) was significantly inhibited regardless of the mode of administration (orally or intraperitoneally). At the high dose of garlic and onion (500 mg/kg), a further decrease of TXB2 levels in the serum of the rats was observed. Boiled garlic and onion at high concentration (500 mg/ kg) had very little effect on TXB2 synthesis. This shows that garlic and onion should be consumed in a raw rather than cooked form in order to achieve a beneficial effect. Boiling of these plants may cause the decomposition of the potential antithrombotic ingredient present in these herbs. Garlic was found to be more potent than onion in lowering the TXB2 levels. A high dose of garlic and onion produces toxicity in the rats (unpublished observation). These results show that garlic and onion can be taken frequently in low doses without any side effects, and can still produce a significant antithrombotic effect.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8860105&dopt=Abstract garlic



garlic
Urinary excretion of N-acetyl-S-allyl-L-cysteine upon garlic consumption by human volunteers.

de Rooij BM, Boogaard PJ, Rijksen DA, Commandeur JN, Vermeulen NP.

Department of Pharmacochemistry, Free University, Amsterdam, The Netherlands.

N-Acetyl-S-allyl-L-cysteine (allylmercapturic acid, ALMA) was previously detected in urine from humans consuming garlic. Exposure of rats to allyl halides is also known to lead to excretion of ALMA in urine. ALMA is a potential biomarker for exposure assessment of workers exposed to allyl halides. It is not known whether garlic consumption can lead to urinary concentrations of ALMA which may interfere with biological monitoring of exposure to allyl halides by determination of urinary ALMA. Therefore, this study was undertaken to determine the cumulative excretion and the excretion kinetics of ALMA in urine of humans consuming garlic. Six human volunteers were given orally two garlic tablets, each containing 100 mg garlic extract (each representing 300 mg fresh garlic). Three of the volunteers consumed additional garlic after the garlic tablet intake. Urine samples were collected up to 24 h after the intake of the garlic tablets. ALMA was identified in the urine using gas chromatography-mass spectrometry (GC-MS) and determined quantitatively with a limit of detection of 0.10 microgram/ml with gas chromatography with sulphur selective detection. The total amount of ALMA found in urine of volunteers who consumed two garlic tablets was 0.43 +/- 0.14 mg (n = 3). In the urine of the three volunteers who consumed not only two garlic tablets but also additional fresh garlic, a significantly higher amount of ALMA was excreted in the urine, 1.4 +/- 0.2 mg (n = 3). The elimination half-life of ALMA, estimated from urinary excretion rate versus time curves, was 6.0 +/- 1.3 h (n = 5). One volunteer, who ate additional garlic, showed an irregular elimination profile and was excluded from this estimation. The highest urinary concentration of ALMA found in this study was 2.2 micrograms/ml. In a preliminary biological monitoring study of exposure in workers with potential exposure to allyl chloride (AC) up to the occupational exposure limit of 1 ppm (8-h TWA), we recently found urinary ALMA concentrations up to 4 micrograms/ml. Based on the results presented here, we conclude that garlic consumption is a potential confounder when monitoring human exposure to allylhalides and other chemicals leading to ALMA excretion when ALMA is used as a biomarker of exposure.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8870956&dopt=Abstract garlic



garlic
Garlic preserves patency and delays hyperthermia-induced thrombosis in pial microcirculation.

el-Sabban F, Fahim MA, Radwan GM, Zaghloul SS, Singh S.

Department of Physiology, Faculty of Medicine and Health Sciences, U.A.E. University, Al Ain, United Arab Emirates.

Three trials were carried out to study the effect of garlic on thrombus formation and patency in the mouse pial microcirculation in response to hyperthermia. Two different hyperthermic exposures, at 43 degrees C for 60 min and at 44 degrees C for 45 min, were applied to the brain surface of anaesthetized mice by heated artificial cerebrospinal fluid (ACSF). Garlic solutions were prepared 24 h prior to their injection, i.p., from a finely-ground powder in saline (pH 7.3) to deliver doses of 25, 50 and 75 mg/kg. Control groups of the three trials were injected with saline, pH 7.3. Garlic and vehicle solution injections were made 60 min prior to the intended hyperthermic exposure. Microvascular responses were monitored and were recorded by intravital videomicroscopy. With core body temperature kept at 37 degrees C and at the elevated ACSF temperatures, the first observed intravascular response was in the form of either passing emboli or as visible thrombosis in either arterioles or venules. Further thromboembolic events continued and throughout such exposures higher arteriolar patency was evident in the garlic-treated mice. Collectively, garlic significantly delayed the appearance of the first observable thrombo/embolic response. Data of this study evidenced that garlic delayed hyperthermia-induced platelet aggregation, in vivo. Such results could prove beneficial to those adversely affected by antithrombotic drugs, like aspirin.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8877475&dopt=Abstract garlic



garlic
Effect of garlic on platelet aggregation in humans: a study in healthy subjects and patients with coronary artery disease.

Bordia A, Verma SK, Srivastava KC.

Department of Medicine, R.N.T. Medical College, Udaipur, India.

Garlic's value in preventing cardiovascular disease has been reported by several research groups. Garlic and its components are known to possess antiplatelet activity which has been demonstrated mostly in vitro. It was found that garlic oil administration to healthy subjects and patients with coronary artery disease (CAD) inhibited platelet aggregation ex vivo. Though garlic components leave the body quickly, a slow build-up of the active ingredients may take place. This was evident from the observation that though a 2-3 fold higher dose was not effective in inhibiting platelet aggregation when administered once, a lower dose became effective in long-term administration.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8931120&dopt=Abstract garlic



garlic
Electrophoretic identification of garlic and garlic products.

Mochizuki E, Yamamoto T, Suzuki S, Nakazawa H.

Yamanashi Institute for Public Health, Japan.

We developed a rapid and simple method for identifying garlic and garlic products using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with silver staining. Samples were homogenized with 1% SDS or 6M urea and centrifuged. Supernatant containing garlic proteins was mixed with the same volume of loading buffer containing SDS and mercaptoethanol, heated in boiling water for 2 min, and applied to the wells of a ready-to-use polyacrylamide gradient gel (4-20%). Electrophoresis was performed 20 mA constant current for 2 h. The gel was stained with a silver staining kit and dried. Protein patterns of garlic and garlic products are different from those of other Allium plants such as onion, rakkyo, and caucas. The method was used to analyze samples of spice and garlic clove products. Absence of protein bands in garlic extract products suggests the products may contain less proteins and/or denatured proteins.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8946725&dopt=Abstract garlic