title: Garlic allicin as a potential agent for controlling oral pathogens.
abstract: Garlic has been used medicinally throughout human history. Allicin is considered the most therapeutic constituent of garlic. This study tested the antimicrobial activity of garlic allicin on oral pathogens associated with dental caries and periodontitis. Allicin was found effective against all the tested bacteria. The broth dilution method revealed that planktonic growth of the cariogenic, gram-positive species Streptococcus mutans, S. sobrinus, and Actinomyces oris was inhibited by an allicin concentration of 600 μg/mL or higher. Planktonic growth of the tested gram-negative periopathogenic species Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum was inhibited by a minimum allicin concentration of 300 μg/mL. Porphyromonas gingivalis, an anaerobic, gram-negative pathogen and the bacterium most associated with chronic periodontitis, demonstrated the lowest sensitivity to allicin (2,400 μg/mL). Gel zymography and the synthetic chromogenic substrate N(α)-benzoyl-L-arginine 4-nitroanilide hydrochloride demonstrated that allicin inhibits the proteases of P. gingivalis, including the arginine and lysine gingipains known as major virulence factors of this organism. A gingipain-inactivated mutant demonstrated high sensitivity to allicin (<300 μg/mL), revealing that gingipains confer resistance to allicin. Live/dead staining followed by analysis with confocal laser scanning microscopy revealed that allicin was bactericidal to S. mutans grown in mature biofilms. However, this bactericidal effect was reduced as biofilm depth increased. In conclusion, these results support the traditional medicinal use of garlic and suggest the use of allicin for alleviating dental diseases.
authors.affiliation: Institute of Dental Sciences, The Hebrew University-Hadassah School of Dental Medicine, Jerusalem, Israel. giladba@ekmd.huji.ac.il
authors.forename: Gilad
authors.initials: G
authors.lastname: Bachrach
authors.forename: Areen
authors.initials: A
authors.lastname: Jamil
authors.forename: Ronit
authors.initials: R
authors.lastname: Naor
authors.forename: Golan
authors.initials: G
authors.lastname: Tal
authors.forename: Zvi
authors.initials: Z
authors.lastname: Ludmer
authors.forename: Doron
authors.initials: D
authors.lastname: Steinberg
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism; D016976:Aggregatibacter actinomycetemcomitans / Q000187:drug effects / Q000254:growth & development / Q000472:pathogenicity; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001120:Arginine / Q000378:metabolism; D018441:Biofilms / Q000187:drug effects*; D003546:Cysteine Endopeptidases / Q000378:metabolism; D003731:Dental Caries / Q000382:microbiology; D004220:Disulfides; D004305:Dose-Response Relationship, Drug; D016967:Fusobacterium nucleatum / Q000187:drug effects / Q000254:growth & development / Q000472:pathogenicity; D005737:Garlic / Q000737:chemistry; D000080867:Gingipain Cysteine Endopeptidases; D008239:Lysine / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D018613:Microscopy, Confocal; D010936:Plant Extracts / Q000494:pharmacology*; D016966:Porphyromonas gingivalis / Q000187:drug effects / Q000254:growth & development / Q000472:pathogenicity; D013295:Streptococcus mutans / Q000187:drug effects* / Q000254:growth & development / Q000472:pathogenicity; D013441:Sulfinic Acids / Q000494:pharmacology*
chemical_list: D018829:Adhesins, Bacterial; D000890:Anti-Infective Agents; D004220:Disulfides; D000080867:Gingipain Cysteine Endopeptidases; D010936:Plant Extracts; D013441:Sulfinic Acids; C006452:allicin; D001120:Arginine; D003546:Cysteine Endopeptidases; D008239:Lysine