8 replies to this topic

[rwac]

Garlic blocks quorum sensing and promotes rapid clearing of pulmonary
Pseudomonas aeruginosa infections
http://mic.sgmjourna...act/151/12/3873

Garlic blocks quorum sensing and promotes rapid clearing of pulmonary Pseudomonas aeruginosa infections
Thomas Bjarnsholt¹, Peter Østrup Jensen², Thomas B. Rasmussen¹, Lars Christophersen², Henrik Calum², Morten Hentzer³, Hans-Petter Hougen⁴, Jørgen Rygaard⁵, Claus Moser², Leo Eberl⁶, Niels Høiby² and Michael Givskov¹

The opportunistic human pathogen Pseudomonas aeruginosa is the predominant micro-organism of chronic lung infections in cystic fibrosis patients. P. aeruginosa colonizes the lungs by forming biofilm microcolonies throughout the lung. Quorum sensing (QS) renders the biofilm bacteria highly tolerant to otherwise lethal doses of antibiotics, and protects against the bactericidal activity of polymorphonuclear leukocytes (PMNs). It has been previously demonstrated that QS is inhibited by garlic extract. In this study, the synergistic effects of garlic and tobramycin, and PMNs activities have been evaluated. P. aeruginosa was grown in vitro in continuous-culture once-through flow chambers with and without garlic extract. The garlic-treated biofilms were susceptible to both tobramycin and PMN grazing. Furthermore, the PMNs showed an increase in respiratory burst activation, when incubated with the garlic-treated biofilm. Garlic extract was administered as treatment for a mouse pulmonary infection model. Mice were treated with garlic extract or placebo for 7 days, with the initial 2 days being prophylactic before P. aeruginosa was instilled in the left lung of the mice. Bacteriology, mortality, histopathology and cytokine production were used as indicators. The garlic treatment initially provoked a higher degree of inflammation, and significantly improved clearing of the infecting bacteria. The results indicate that a QS-inhibitory extract of garlic renders P. aeruginosa sensitive to tobramycin, respiratory burst and phagocytosis by PMNs, as well as leading to an improved outcome of pulmonary infections.

Effects of Fresh Garlic Extract on Candida albicans Biofilms
http://www.ncbi.nlm....icles/PMC538912

Effects of Fresh Garlic Extract on Candida albicans BiofilmsJennifer A. Shuford, James M. Steckelberg, and Robin Patel^* The effects of fresh garlic extract (FGE) against planktonic Candida spp. have been demonstrated in vitro and have been attributed to the action of allicin (3), a sulfur-containing compound that is formed at levels of approximately 3 to 5 mg/g of fresh clove (8). Biofilm-associated, or sessile, Candida albicans organisms demonstrate increased resistance to traditional antifungal agents that have activity against their planktonic counterparts (5). Therefore, we investigated the activity of FGE against both planktonic and sessile forms of C. albicans.

0411 Garlic Allicin as a Means to Control Oral Pathogens
http://iadr.confex.c...tract_96642.htm

0411 Garlic Allicin as a Means to Control Oral Pathogens A. JAMIL¹, D. STEINBERG¹, Z. LUDMER², T. GOLAN², R. NAOR¹, and G. BACHRACH¹, ¹Hebrew University Hadassah, Jerusalem, Israel, ²Hebrew University, Rhovot, IsraelIntroduction: Periodontal disease is a chronic bacterial infection that affects the gums and bone supporting the teeth. Porphyromonas gingivalis is a Gram-negative anaerobe that is implicated as the major etiologic agent of adult periodontitis. P. gingivalis produces cysteine proteinases termed gingipains, in cell-associated and secretory forms. Gingipains consist of arginine-X-specific proteinases (Arg-gingipains, Rgps) and lysine-X-specific proteinase (Lys-gingipain, Kgsp). Previous studies using various P. gingivalis mutants deficient in the Rgp- and/or Kgp-encoding genes revealed that these enzymes are important for the bacterium's virulence and survival in the periodontal pockets. Thus, development of gingipains inhibitors provides new therapeutic approaches to treat periodontal diseases. Herbal extracts have been used as therapeutic agents throughout the human history. Allicin is a powerful medicinal compound derived from garlic and provides reputed health benefits. Aim: In this study the potential of a unique garlic allicin extract was tested as a means to control oral pathogens. Materials and Methods: Allicin was extracted from garlic and stabilized by solvent extraction. Bacterial growth inhibition by allicin was determined using the broth dilution method. Allicin's antiproteolytic activity was determined using nondenaturing SDS-polyacrylamid gel zymography and by using the chromogenic substrate N-benzoyl –L-Arg-p-nitroanilide(pNA). Streptococcus mutans biofilm inhibition and killing was determined using live dead staining followed by confocal laser scanning microscopy. Results: 1- Allicin was found to inhibit growth of all tested bacteria (P. gingivalis, Fusobacterium nucleatum, Actinobacillus (Aggregatibacter) actinomycetemcomitans, Streptococcus mutans, S. sobrainus, Escherichia coli, and Actinomyces viscosus). 2 - Allicin was found to be a potent irreversible inhibitor of the P. gingivalis proteases. 3- Allicin was found capable of killing S.mutans growth in biofilm. Conclusion: Our results suggest that our Garlic allicin extract has a potential use for prevention and treatment of periodontal disease.

Control of Biofilm Infections by Signal Manipulation
http://bit.ly/cYCgGU
 garlic_mice.PNG   59.47KB   13 downloads

[VespeneGas]

wow, excellent thread, looks like it slipped through the cracks! Perhaps it belongs in 'supplements', where it will get more much-deserved traffic. I've been waiting to hear about some nutritional intervention against biofilms (outside the mouth and intestine), and this looks great, given garlic's record for safety and association with positive health outcomes. I hope they test MK4 some time soon.


FEMS Immunol Med Microbiol. 2009 Sep 18. [Epub ahead of print]
Garlic blocks quorum sensing and attenuates the virulence of Pseudomonas aeruginosa.
Harjai K, Kumar R, Singh S.

Department of Microbiology, Basic Medical Sciences Block, Panjab University, Chandigarh, India.
Abstract
Abstract Pseudomonas aeruginosa is an opportunistic pathogen that colonizes urinary catheters, forms biofilms, and is responsible for causing persistent and recurrent nosocomial catheter-associated urinary tract infections (UTIs). These infections show increased morbidity and mortality in immunocompromised patients. Quorum sensing in P. aeruginosa plays a key role in biofilm formation, virulence factor production and antimicrobial resistance. Because of emerging antimicrobial resistance in P. aeruginosa, there is a need to find an alternate nonantibiotic agent for the control of infections caused by this organism. In the present study, garlic was evaluated as a prophylactic agent in vivo in a mouse UTI model. Oral treatment with garlic significantly lowered renal bacterial counts and protected mouse kidney from tissue destruction. In vitro data showed decreased elaboration of virulence factors and reduced production of quorum-sensing signals by P. aeruginosa in the presence of fresh garlic extract. The results suggest that decreased virulence of P. aeruginosa in garlic-fed mice can be attributed to the quorum-sensing inhibitory property of garlic. This might have contributed towards reduced production of virulence factors, as seen in vitro.

PMID: 19878318 [PubMed - as supplied by publisher]

[rwac]

I wonder what the traffic is to 'bioscience' vs 'supplements'. This thread has nearly 300 views right now.

Edited by rwac, 13 April 2010 - 02:29 AM.

[Sillewater]

Awesome, I eat garlic everyday.

[kbal]

Eating garlic did not do much for me, on the other hand garlic oil in capsules made my male member much 'harder'.

[Matt]

AllicinMax is used here in the UK for MRSA infections, at least at a few hospitals where it was trialled. It was in the news a few years ago all 52 patients got cured from taking allicin. They volunteered after failing ALL antibiotic therapy, some upto 2 years. They were given AllicinMax alone or combined with the cream. No side effects was reported with upto 1000mg+ of Allicin a day. Most were cured before 12 weeks, all were cured by 18 weeks. One problem there was no control group, but 52 out of 52 being cured is pretty good, no? lol

Earlier there was a study showing that allicin is not absorbed but im not sure if they used this stabilised allicin supplement... but again a double blind placebo controlled trial using allicinmax showed that it halved the number of colds and the garlic group only were sick for 1 day compared to 5 days in the placebo if they DID get sick.

[stephen_b]

"[double blind, placebo controlled] trials would cost millions he doesn't have". Sigh.

Counter arguments from a seller of aged garlic extract, whose aging process removes allicin. What I wonder about is whether allicin is the active ingredient.

[Matt]

Garlic extract and two diallyl sulphides inhibit methicillin-resistant
Staphylococcus aureus infection in BALB/cA mice
http://jac.oxfordjou...t/52/6/974.full

Conclusions: These data strongly supported the conclusion that garlic extract,
diallyl sulphide and diallyl disulphide possessed multiple protective functions
against MRSA infection, in which diallyl sulphide and diallyl disulphide could
be considered as novel therapeutic agents for the treatment of MRSA infection.

[stephen_b]

Nice to see that supporting evidence that aged garlic extract, which contains diallyl disulfide, is also helpful (PMID 15802821).