Garlic antimicrobial activity

A tree, Scorodocarpus borneensis, native to Borneo and the Malay peninsula, has a garlic-like smell and is known as wood garlic . The fruit is used locally for seasoning. The major volatile flavor compounds from wood garlic are similar to those of garlic itself. Some of these materials are polysulfur compounds and have antimicrobial activity against some bacteria and fungi. These materials contain four sulfur atoms.75 They are either 2,4,6-trithiaheptane-5-thione-2,2-dioxide (CH3-SO2-CH2-S-CS-S-CH3) or derivatives of tetrathia-octane (CH3-S-CH2-S-S-CH2-S-CH 3, CH3-SO2-CH2-S-S-CH2-S-CH3, CH3-S-CH2-SO2-S-CH2-S-CH3). 

Antimicrobial activities of garlic and onion oil appeared to be determined by the concentrations of individual constituent sulfides. Sulfides with a single sulfur atom were not active, and sulfides with three or four sulfur atoms were highly inhibitory against the growth of Candida utilis and Staphylococcus aureus [109, 110]. 

Garlic is used for a variety of reasons, and some of the attributes associated with it, e.g. for cancer prevention, or to reduce heart attacks, may not be substantiated. Other properties such as antimicrobial activity, effects on lipid metabolism, and platelet aggregation inhibitory action have been demonstrated. Ajoene has been shown to be a potent antithrombotic agent through inhibition of platelet aggregation. 

A number of studies have focused on identifying the active antimicrobial principles in fresh garlic extract. Allicin has been identified as the active agent in garlic extracts. The antifungal activity of allicin has been shown to depend on the sulfhydryl moiety because activity is destroyed by thiols such as L-cysteine, glutathione, and mercaptoethanol. Ajoene, a compound found in oil-macerated garlic, has also been shown to have antimicrobial activity (Ali et al., 2000). 

Groppo FC, Famacciato JC, Simoes RP, et al. Antimicrobial activity of garlic, tea tree oil and chlorhexidine against oral microorganisms. Int Dent J 2002 52 433 137. 

Ajoene, another garlic derivative, has exhibited antimicrobial activities (Yoshida et al., 1999) and, when used with chloroquine, has been shown to increase the antimalarial activity of chloroquine against the parasite P. berghei (Perez et al., 1994). 

Elnima, E., et al. "The Antimicrobial Activity of Garlic and Onion Extract." Pharmazie 38 747748, 1983. 

Pranoto, Y., Rakshit, S.K., Salokhe, V.M. 2005b. Enhancing antimicrobial activity of chitosan films by incorporating garlic oil, potassium sorbate and nisin. LWT—Food Science and Technology, 38(8) 859-865. 

Seydim, A. C. 2006. Antimicrobial activity of whey protein based edible films incorporated with oregano, rosemary, and garlic essential oUs. Food Research International, 39 639-644. 

Table V. Antimicrobial Activity of the Polysulfldes Isolated from Wood Garlic...

Benkeblia N (2004) Antimicrobial activity of essential oil extracts of various (mirats (Allium cepa) and garlic (Allium sativum). Lebensm-Wiss u Technol 37 263... 

Yoshida H, Iwata N, Katsuzaki H et al (1998) Antimicrobial activity of a compound isolated from an oil-macerated garlic extract. Biosd Biotechnol Biochem 62(5) 1014-1017... 

Some experiments indicate positive results of including plants/plant exhacts on inhibition of methanogenesis. In one experiment Terminalia chebula, Allium sativum and the mixture of two were fed to sheep at the rate of 1% of DM1, resulted in a decreased (p=0.09) methane production by 24%, 11% and 23.5% in T. chebula, A. sativum and the mixture of the two, respectively, when expressed as L/kg digestible DM intake (Patra et al. 2010). T. chebula is a rich source of tannin (4.89% of DM), whereas, A satium is rich in essential oils. The data indicated that T. chebula was more effective as compared to garlic. The reason for low A. sativum activity might be due to the instability of alhcin, the main secondary metabolite responsible for antimicrobial activity of A. sativum. 

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