(The following is an abstract summary of an excellent study on the effects of Monolaurin on Candida albicans. It is brief and easy to read – for an abstract.)
In Vitro Killing of Candida albicans by Fatty Acids and Monoglycerides
Gudmundur Bergsson,1* Jóhann Arnfinnsson,2 Ólafur Steingrímsson,3 and Halldor Thormar1
Institute of Biology, University of Iceland,1 Department of Anatomy, University of Iceland Medical School,2 and Department of Microbiology, National University Hospital,3 Reykjavik, Iceland. August 9, 2001.
The susceptibility of Candida albicans to several fatty acids and their 1-monoglycerides was tested with a short inactivation time. Ultrathin sections were studied by transmission electron microscopy (TEM) after treatment with capric acid.
The results show that capric acid (monocaprin), a 10-carbon saturated fatty acid, causes the fastest and most effective killing of all three strains of C. albicans tested, leaving the cytoplasm disorganized and shrunken because of a disrupted or disintegrated plasma membrane. Lauric acid (monolaurin), a 12-carbon saturated fatty acid, was the most active at lower concentrations and after a longer incubation time. (Both in our Monolaurin formula.)
Candida albicansis normally present in small numbers in the oral cavity, lower gastrointestinal tract, and female genital tract. Most C. albicans infections are caused by endogenous flora except in cases of direct mucosal contact with lesions, for example, through sexual intercourse. With a breakdown of host defenses, the organism can produce diseases ranging from superficial skin or mucous membrane infections, e.g., oral lesions called thrush and vaginal candidiasis, to systemic involvement of multiple organs.
Infections are often a complication of broad-spectrum antibacterial therapy. Candida infections of visceral organs have a particularly strong association with immunologic compromise or other violations of normal defense mechanisms (10).
Medium-chain free fatty acids and their corresponding 1-monoglycerides have been found to have a broad spectrum of microbicidal activity against enveloped viruses and various bacteria in vitro (5, 7, 11, 12, 14). This included pathogens like herpes simplex virus (8, 12), Neisseria gonorrhoeae (2), Chlamydia trachomatis (1), group A streptococci, group B streptococci (GBS), and Staphylococcus aureus (3).
The mechanism by which these lipids kill bacteria is not known, but electron microscope studies indicate that they disrupt cell membranes (1, 3, 12). The lipids are commonly found in natural products, for example, in milk (lactoferrin and monolaurin), and are therefore likely to be nontoxic to mucosas, at least at low concentrations.
In milk and mucosas these compounds are considered to be potent inhibitors of many human pathogens or parasites (4, 5). This work was done in order to find if some fatty acids or their 1-monoglycerides might inactivate C. albicans and therefore be useful for treatment of infections of skin and mucosas caused by this pathogen.
In summary, the results show that both capric and lauric acids are active in killing C. albicans and may, therefore be useful for treatment of infections caused by that pathogen or others that infect the skin and mucosa, possibly in conjunction with antibiotic therapy over a longer period of time.
1.Bergsson G, Arnfinnsson J, Karlsson S M, Steingrímsson Ó, Thormar H. In vitro inactivation ofChlamydia trachomatis by fatty acids and monoglycerides. Antimicrob Agents Chemother. 1998;42:2290–2294.
2.Bergsson G, Steingrímsson Ó, Thormar H. In vitro susceptibilities of Neisseria gonorrhoeae to fatty acids and monoglycerides. Antimicrob Agents Chemother. 1999;43:2790–2792.
3.Bergsson, G., J. Arnfinnsson, Ó. Steingrímsson, and H. Thormar. Killing of gram-positive cocci by fatty acids and monoglycerides.
4.Isaacs C E, Kim K S, Thormar H. Inactivation of enveloped viruses in human bodily fluids by purified lipids. Ann N Y Acad Sci. 1994;724:457–464.
5.Isaacs C E, Litov R E, Thormar H. Antimicrobial activity of lipids added to human milk, infant formula, and bovine milk. Nutr Biochem. 1995;6:362–366.
6.Kabara J J, Swieczkowski D M, Conley A J, Truant J P. Fatty acids and derivatives as antimicrobial agents. Antimicrob Agents Chemother. 1972;2:23–28.
7.Kabara J J. Fatty acids and derivatives as antimicrobial agents. In: Kabara J J, editor. The pharmacological effect of lipids. St. Louis, Mo: American Oil Chemists Society; 1978. pp. 1–14.
8.Kristmundsdóttir T, Árnadóttir S, Bergsson G, Thormar H. Development and evaluation of microbicidal hydrogels containing monoglyceride as the active ingredient. J Pharm Sci. 1999;88:1011–1015.
9.Neyts J, Kristmundsdóttir T, De Clercq E, Thormar H. Hydrogels containing monocaprin prevent intravaginal and intracutaneous infections with HSV-2 in mice: impact on the search for vaginal microbicides. J Med Virol. 2000;61:107–110
10.Ryan K J. John C. Sherris (ed.), Medical microbiology, an introduction to infectious diseases. 2nd ed. New York, N.Y: Elsevier Science Publishing Co., Inc.; 1990. Candida and other opportunistic fungi; pp. 651–657.
11.Shibasaki I, Kato N. Combined effects on antibacterial activity of fatty acids and their esters against gram-negative bacteria. In: Kabara J J, editor. The pharmacological effects of lipids. St. Louis, Mo: American Oil Chemists Society; 1978. pp. 15–24.
12.Thormar H, Isaacs C E, Brown H R, Barshatzky M R, Pessolano T. Inactivation of enveloped viruses and killing of cells by fatty acids and monoglycerides. Antimicrob Agents Chemother. 1987;31:27–31.
13.Thormar H, Bergsson G, Gunnarsson E, Georgsson G, Witvrouw M, Steingrímsson Ó, De Clercq E, Kristmundsdóttir T. Hydrogels containing monocaprin have potent microbicidal activities against sexually transmitted viruses and bacteria in vitro. Sex Transm Infect. 1999;75:181–185.
14.Welsh J K, Arsenakis M, Coelen R J, May J T. Effect of antiviral lipids, heat, and freezing on the activity of viruses in human milk. J Infect Dis. 1979;140:322–328.