The effect of garlic on arteriosclerotic nanoplaque formation and size

Chemical and biological properties of bio-active compounds from garlic (Allium sativum)

Garlic (Allium sativum) is one of the oldest cultivated plants. It has been used as a spice, food, and folk medicine for many years. Garlic contains about 2000 biologically active components. For centuries, scientists have obtained a variety of compositions and physiological activities of garlic, depending on the methods of processing and extraction. Many review articles were published, where the object of the study was garlic. But there are very few broad literature reviews where garlic has been fully disclosed as a medicinal raw material. The study found that some garlic products and processing procedures were not standardized or tested for safety. A broad overview of this object can direct the attention of the scientific community in the right direction. This review contains various processing methods and yields from these extracts. In addition, most of the key physiological properties of the active substances of the raw materials are prescribed.

Effect of garlic powder tablet on carotid intima-media thickness in patients with coronary artery disease: a preliminary randomized controlled trial

BACKGROUND/OBJECTIVES

This study was designed to investigate whether garlic powder tablets in adjunct to conventional medical treatment could have an effect on carotid intima-media thickness (CIMT) and plasma lipoproteins and lipids in patients with coronary artery disease (CAD).

SUBJECTS/METHODS

A randomized, placebo-controlled, clinical trial was conducted on 56 patients with CAD between the ages of 25 and 75 years. The patients were randomly divided into two groups: garlic group (n = 27), receiving garlic powder tablet (1200 µg allicin/tab) twice daily and the placebo group (n = 29), receiving placebo for 3 months. The rate of atherosclerosis progression was measured by B-mode ultrasonography as the increase in CIMT.

RESULTS

After 3 months of taking garlic tablets, CIMT values had minor variations (0.009 ± 0.007 mm reduction from baseline), while in the placebo group, an increase in CIMT values was observed (0.04 ± 0.01 mm increase from baseline). After 3 months of treatment, mean CIMT difference from baseline was significantly differ between the two groups (p < 0.001). Plasma lipids and lipoproteins (total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, Apolipoprotein A1 and Apolipoprotein B) did not differ between the two groups.

CONCLUSIONS

The results suggest that dry garlic powder tablet is superior to placebo in prevention of CIMT progression in patients with CAD and may be considered as an adjunct treatment for atherosclerosis.

Sulfur compounds identification and quantification from Allium spp. fresh leaves

Pyruvic acid concentration is a Allium spp. pungency. This study was initiated to accurately measure the background pyruvic acid levels in Romanian Allium spp. From the pungency point of view, all analyzed plant varieties in this study are considered low pungent cultivars based on the enzymatically produced pyruvate level (between 42 μmol/g and 222 μmol/g fresh wt). Chromatographic analysis was carried out for the different varieties of the most popular fresh leaves (Allium cepa var. “Diamant”, Allium cepa var. “Rubiniu”, and Allium ursinum L.) in order to identify the sulfur compounds. The thin layer chromatography analysis led to the identification of allicin, with R_f = 0.377–0.47, as an important sulfur compound. The gas chromatography-mass spectrometry analysis of the leaves’ extracts detected disulfides as the major sulfur compounds. Principal component analysis was performed to establish the differences in plant composition. These studies suggest the potential good uses of the fresh leaves of Romanian Allium spp. as condiment, ingredient, or preservative in the food industry.

Inhibitory effect of methyl methanethiosulfinate on β-glucuronidase activity

Minced or cut-up leaves of Chinese chive (Allium tuberosum Rottler) contain thiosulfinates and their disproportionate reaction products. Among these organosulfur compounds, methyl methanethiosulfinate was found to be an uncompetitive inhibitor of β-glucuronidase. Approximately 80% of the enzyme activity was inhibited by methyl methanethiosulfinate at 50 µM, the IC50 value being comparable to 3.6 µM.

Graphene-supported zinc oxide solid-phase microextraction coating with enhanced selectivity and sensitivity for the determination of sulfur volatiles in Allium species

A graphene-supported zinc oxide (ZnO) solid-phase microextraction (SPME) fiber was prepared via a sol-gel approach. Graphite oxide (GO), with rich oxygen-containing groups, was selected as the starting material to anchor ZnO on its nucleation center. After being deoxidized by hydrazine, the Zn(OH)2/GO coating was dehydrated at high temperature to give the ZnO/graphene coating. Sol-gel technology could efficiently incorporate ZnO/graphene composites into the sol-gel network and provided strong chemical bonding between sol-gel polymeric SPME coating and silica fiber surface, which enhanced the durability of the fiber and allowed more than 200 replicate extractions. Results indicated that pure ZnO coated fiber did not show adsorption selectivity toward sulfur compounds, which might because the ZnO nanoparticles were enwrapped in the sol-gel network, and the strong coordination action between Zn ion and S ion was therefore blocked. The incorporation of graphene into ZnO based sol-gel network greatly enlarged the BET surface area from 1.2 m2/g to 169.4 m2/g and further increased the adsorption sites. Combining the superior properties of extraordinary surface area of graphene and the strong coordination action of ZnO to sulfur compounds, the ZnO/graphene SPME fiber showed much higher adsorption affinity to 1-octanethiol (enrichment factor, EF, 1087) than other aliphatic compounds without sulfur-containing groups (EFs<200). Also, it showed higher extraction selectivity and sensitivity toward sulfur compounds than commercial polydimethylsiloxane (PDMS) and polydimethylsiloxane/divinylbenzene (PDMS/DVB) SPME fibers. Several most abundant sulfur volatiles in Chinese chive and garlic sprout were analyzed using the ZnO/graphene SPME fiber in combination with gas chromatography-mass spectrometry (GC-MS). Their limits of detection were 0.1-0.7 μg/L. The relative standard deviation (RSD) using one fiber ranged from 3.6% to 9.1%. The fiber-to-fiber reproducibility for three parallel prepared fibers was 4.8-10.8%. The contents were in the range of 1.0-46.4 μg/g with recoveries of 80.1-91.6% for four main sulfides in Chinese chive and 17.1-122.6 μg/g with recoveries of 73.2-80.6% for three main sulfides in garlic sprout.

Effects of water garlic extracts on cell cycle and viability of HepG2 hepatoma cells

Garlic extracts, either aqueous or oily, are commonly employed to prepare garlic derivative supplements used as nutraceuticals for the treatment of different pathologies. In this study, we investigated the effects of water garlic extracts from two different areas of Italy well known for garlic production, Latina (GEL) and Sulmona (GES), on cell cycle and death of HepG2 hepatoma cells. The effects of the treatments with GEL and GES were also compared with the oil-soluble sulfur compound of garlic, diallyl disulfide (DADS). GEL and GES induced a p53/p21-dependent cell cycle arrest in G2/M phase and apoptosis, although to a different extent, whereas DADS, under the experimental conditions used, was not detrimental to HepG2 cells. GEL and GES committed HepG2 cells to apoptosis by the activation of c-Jun-NH(2) terminal kinase (JNK)/c-Jun phosphorylative cascade without a detectable increase in the flux of reactive oxygen species. Moreover, differentiation of HepG2 cells induced by retinoic acid determined resistance to GEL and GES treatments without the activation of JNK signaling pathway. Overall, the results obtained indicate that water-soluble garlic extracts are more inhibitory of the growth of transformed hepatoma cells than the oil-soluble isolated compound DADS, and that their antiproliferative properties are different depending on the area of origin of the starting material.

Herbal Supplements: Facts and Myths—Talking to Your Patients About Herbal Supplements

The use of herbal supplements in the United States is steadily growing and raises concerns about safety, efficacy, and how they affect safe patient care. The direct health risks associated with herbal supplements include hypertension, prolonged bleeding, and the potential for drug-herb interactions. These potential drug interactions are of particular concern for patients undergoing anesthesia. This article provides a review of literature on the 10 most popular herbal supplements and addresses the herbal supplements' reported use, possible adverse effect(s), patient teaching, possible drug interaction(s), and recommendations regarding discontinuation before surgery.

Garlic Compound, Diallyl Disulfide Induces Cell Cycle Arrest in Prostate Cancer Cell Line PC-3

Prostate cancer is the most predominant cancer in men and related death rate increases every year. Till date, there is no effective therapy for androgen independent prostate cancer. Previous studies reported that aged garlic extract suppresses cancer growth. In the present study, diallyl disulfide [DADS], oil soluble organosulfur compound of garlic, was studied for its antiproliferative and induction of cell cycle arrest on prostate cancer cells in vitro. The suppression of cell growth was assessed by MTT assay. Induction of cell cycle arrest was assessed and confirmed by propidium iodide staining in flowcytometric analysis and western blotting analysis of major cell cycle regulator proteins. The results showed that DADS inhibited the growth of prostate cancer cells in a dose dependent manner, compared to the control. At 25 microM and 40 microM concentrations, DADS induced cell cycle arrest at G2/M transition in PC-3 cells. Western blotting analysis of cyclin A, B(1) and cyclin dependent kinase 1 [CDK1] revealed that DADS inhibited the cell cycle by downregulating CDK1 expression. It is concluded that DADS, inhibits proliferation of prostate cancer cells through cell cycle arrest. Dose dependent effect of DADS on PC-3 cell line was observed in the present study.

Aged garlic extract and its constituents inhibit platelet aggregation through multiple mechanisms

Aged garlic extract (AGE) is a complex mixture. Its constituents include allin, cycloalliin, S-allyl-L-cysteine, S-methyl-L-cysteine, S-ethylcysteine, S-1-proponyl-L-cysteine, S-allylmercapto-L-cysteine, fructosyl-arginine, and beta-chlorogenin. It also contains L-arginine, L-cysteine, and L-methionine. AGE reduces the parameters associated with cardiovascular disease, including the inhibition of platelet aggregation. However, the underlying mechanisms have yet to be established and are the subject of this study. AGE inhibited platelet aggregation in a concentration-dependent manner, and this achieved significance between concentrations of 1.56-25% (v:v). The constituents of AGE, when tested as a mixture, displayed a biphasic pattern of inhibition, although this was not significant. L-Methionine displayed anti-aggregatory properties at concentrations of 0.00078, 0.00625, and 0.1 mmol/L, whereas L-arginine and L-cysteine were effective at 9 mmol/L. However, when the constituents and the amino acids were tested together, significant inhibition of platelet aggregation was observed only at a concentration of 1 mmol/L. AGE also displayed disaggregatory properties at concentrations of 12.5 and 25% (v:v). The constituents and the amino acids, when tested as a mixture, displayed disaggregatory properties at concentrations of 0.25 and 1 mmol/L. In contrast, a diethyl-ether extract of AGE had no effect on platelet aggregation. When platelets were stimulated with either A23187 or ADP, an increase in intraplatelet Ca2+ accompanied platelet aggregation. This increase in Ca2+ was abolished in the presence of AGE. It is likely that AGE works in a synergistic manner and exerts multiple effects on the biochemical pathways involved in platelet aggregation.

Overview on the Analytical Tools for Quality Control of Natural Product-Based Supplements: A Case Study of Ginseng

The quality of pharmaceutical products like ginseng is important for ensuring consumer safety and efficacy. Many ginseng products sold today are in various formulations such as powder, capsules, tablets, soft-gels, liquid extracts, and tea. This renders ginseng less identifiable by smell, taste, or physical appearance. Furthermore, as ginseng is expensive, adulteration with other cheaper products occurs. Hence quality assurance of ginseng is needed. This paper reviews the major techniques for ascertaining the level of ginsenosides, the primary active ingredients for ginseng, and covers high-performance liquid, gas, and thin-layer chromatographies, infrared and nuclear magnetic resonance spectroscopies, enzyme immunoassays, and other molecular methods. Supporting techniques such as ultraviolet, fluorescence, diode array and evaporative light scattering detections, and mass spectrometry will also be touched upon. This review also discusses the principles and applications of biosensors-in particular fiber optic-based sensors-and their feasibility in ginseng analysis based on preliminary studies. Despite their potential, there is currently no or limited commercial exploitation of fiber optic-based sensors to perform ginseng quality analysis. The opportunity for biosensors to be used for the rapid quality surveillance of ginseng is appealing, but several key issues still need to be addressed before they find widespread applications in the traditional Chinese medicine industry.

Differential effects of allyl sulfides from garlic essential oil on cell cycle regulation in human liver tumor cells

In this study, diallyl sulfide (DAS), diallyl disulfide (DADS) and diallyl trisulfide (DATS), which are major organosulfur compounds (OSCs) of garlic, were used as experimental materials to investigate their modulation effects on cell viability and cell cycle in human liver tumor cells (J5). According to the results of cell viability assay, 50 or 100 microM DATS significantly decreased the cell viability as compared with the control (P < 0.05) in dose and time dependent relations. Phenomena of cell number loss, shape deformation and lysis were observed after treatment with 100 microM DATS for 24 h. Cell cycle studies showed that J5 cells were significantly arrested in G2/M phase as the cells were treated with 100 microM DADS, 10, 50 or 100 microM DATS for 24 h (P < 0.05). DATS was more effective in arresting cells in G2/M phase than DADS, and the phenomena of arresting J5 cells in G2/M phase increased obviously in dose and time dependent relations. According to the Western blot analysis, DATS decreased cyclin-dependent kinase (Cdks)-Cdk7 (i.e. Cdc2 activate kinase) protein levels in J5 cells but increased cyclin B1 protein level. The modulation potency to cyclin B1 and Cdk7 expressions was in the order of DATS > DADS > DAS. The modulation potency to cyclin B1 and Cdk7 protein levels increased with increasing in DATS concentration and culture time. In conclusion, DATS might affect cell viability and cell morphological changes in J5 cells and lead cells to be arrested in G2/M phase via controlling the expression of cyclin B1 and Cdk7 in J5 cells, and the controlling action might relate to the sulfuric atom numbers in the structures of all these allyl sulfides.