This organic compound is a white powdered solid with a slight aromatic/phenolic odor. It is a chlorinated aromatic compound which has functional groups representative of both ethers and phenols. Phenols often show anti-bacterial properties. Triclosan is slightly soluble in water, but soluble in ethanol, diethyl ether, and stronger basic solutions such as 1 M sodium hydroxide, like many other phenols.

Uses

It is found in soaps, deodorants, toothpastes and is impregnated in an increasing number of consumer products, such as kitchen utensils, toys, bedding, socks, and trash bags. It has been shown to be effective in reducing and controlling bacterial contamination on the hands and on treated products.

Triclosan is regulated by both the U.S. Food and Drug Administration and by the European Union. In the environment, triclosan is removed during normal waste treatment processes as shown by extensive environmental studies, and any of it that remains after waste treatment quickly breaks down into other compounds in the environment. However, one study showed that triclosan was broken down into dioxins in river water, because of the presence of sunlight (PMID 15779749).

Mechanism of action

Triclosan appears to kill bacteria mainly by inhibiting fatty acid synthesis. Triclosan binds to bacterial enoyl-acyl carrier protein reductase (encoded by FabI) and increases the enzyme's affinity for nicotinamide adenine dinucleotide (NAD⁺). This results in the formation of a stable ternary complex of FabI-NAD⁺-triclosan, which is unable to participate in fatty acid synthesis. Some bacterial strains are resistant to triclosan due to FabI mutations which decrease triclosan's effect on FabI-NAD⁺ binding. (PMID 10196195) Another way for bacteria to gain resistance to triclosan is to overexpress FabI (PMID 11418506).

Resistance concerns

An article coauthored by Dr. Stuart Levy in the August 6, 1998 issue of Nature (PMID 9707111) warned that its overuse could cause resistant strains of bacteria to develop, in much the same way that antibiotic-resistant bacterial strains are emerging, based on speculation that triclosan behaved like an antibiotic. Based on this speculation, in 2003, the Sunday Herald newspaper reported that some UK supermarkets and other retailers were considering phasing out products containing triclosan.

It has since been shown that the laboratory method used by Dr. Levy was not effective in predicting bacterial resistance for biocides like triclosan, based on work by Dr. Peter Gilbert in the UK (PMID 12957932). At least seven peer-reviewed and published studies have been conducted demonstrating that triclosan is not significantly associated with bacterial resistance, including one study coauthored by Dr. Levy, published in August of 2004 in Antimicrobial Agents and Chemotherapy (PMID 15273108). In addition, there is 30 years of experience with triclosan without any incidences of acquired bacterial resistance reported, and there are no studies showing acquired resistance after long-term use.

Read more at Wikipedia.org

• [List your site here Free!]

Mouthwash may treat malaria - triclosan - News
From British Medical Journal, 2/10/01 by Abi Berger

Triclosan, a substance commonly found in mouthwashes and deodorants, has shown promise as an antimalarial treatment.

Researchers in India have been investigating the use of triclosan as an antimalarial and have found that in mice this antimicrobial agent can completely clear the parasite. Dr Namita Suriola and her team at the Jawaharlal Nehru Centre for Advanced Scientific Research in Bangalore have also identified the metabolic pathway by which triclosan seems to work (Nature Medicine 2001;7:167-72).

One of the critical enzymes involved in the synthesis of fatty acids in plants and many bacteria is called enoyl-acyl-carrier protein reductase, or FabI. As the type of fatty acid synthesis in plants is also implicated in the malaria parasite, but not in mammalian cells, Dr Suriola's team took the approach that FabI might be a suitable target for antimalarial treatment.

They chose triclosan as a potential candidate drug because it had recently been shown to target and inhibit FabI in bacterial systems.

Their results showed that triclosan inhibited the growth of Plasmodium falciparum in red blood cells in vitro. They went on to show that subcutaneous triclosan administered to mice infected with Plasmodium berghei (a model for human malaria) cleared the parasite from peripheral blood and prevented death.

Dr Suriola has identified and purified a protein in P falciparum that has a similar sequence to the FabI enzymes of bacteria, and she also identified a potential fabI gene from the P falciparum genome database. She believes this gene represents a new target for antimalarial drug development.

Triclosan has a favourable safety profile when used topically as an antibacterial agent. Observations of resistance in Escherichia coli suggest that triclosan would probably have to be used in conjunction with other antimalarial treatments to prevent the sort of resistance now observed with drugs such as chloroquine.

Return to Triclosan

Home

Contact

Resources

Exchange Links

ebay