Lufenuron

The range of candida treatments ranges from time-proven and safe fatty acids, to dangerous drugs that create resistant strains, to obscure treatments like turpentine. With candida being an orphaned condition by the medical profession, many people take advantage of this void by selling anything they can to make a buck. While promising a quick cure, they put down everything and everyone else in an attempt to steer people away from following sound advise. Lufenuron is a good example of this trend. Designed and marketed as a flea medication for pets, at least two sites are trying to market it as a treatment for candida, in spite of the science that shows it doesn’t work against fungus.

Lufenuron is being pitched to candida sufferers as an effective anti-fungal due to its ability to act as a chitin synthesis inhibitor. Chitin makes up a good portion of the exoskeletons of insects and chitin inhibitors can cause this exoskeleton to break down. Chitin is also found in the cell wall of candida to varying degrees, depending on the environmental stresses that candida encounters. Unlike the exoskeleton of insects, candida has an ability to manipulate the chitin content in its cell wall membranes. If the environment that it finds itself in has chitin inhibitors, candida will alter its chitin content to preserve the integrity of its cell wall membrane. Sites that sell lufenuron would like you to think that candida doesn’t have this ability, which reveals a deep misunderstanding of how candida works.

Research

Researchers from the University of California, San Francisco, decided to look at whether or not lufenuron had any anti-fungal effects. They found, “No evidence of inhibition, either by susceptibility testing or direct microscopic examination of treated cells, was obtained with lufenuron“. In contrast, they showed that a known chitin synthesis inhibitor, Nikkomycin Z, had a potent inhibitory effect against chitin in fungal cell wall membranes. Their conclusion –  “lufenuron does not appear to possess anti-fungal properties”.

Examining the scientific literature on lufenuron reveals other information that these sites fail to mention:

Lufeneron showed initial promise as a treatment for fungal infections, but the early enthusiasm has dampened considerably as efficacy appears doubtful.

Adverse effects reported in dogs and cats after oral lufenuron include: vomiting, lethargy/depression, pruritus/urticaria, diarrhea, dyspnea, anorexia, and reddened skin. The manufacturer reports that the adverse reaction rate is less than 5 animals in one million doses. http://www.peteducation.com/article.cfm?c=26+1303&aid=1471

Of relevance to microbiology, chitin is present in fungal species such as mushrooms, where it can comprise from 5% to 20% of the weight of the organism.

Chitin synthesis inhibitors share a similar chemical structure as other benzoylphenyl ureas.Their mode of action is by interfering with the polymerization pathway of chitin, inducing accumulation of the monomer uridine diphospho-N-acetylglucosamine and blocking its synthesis (Beeman 1982). 

The final step  of  chitin  biosynthesis is  the polymerization of  N-acetylglucosamine from  the  activated  substrate  UDP-N-acetylglucosamine,  by  the  enzyme  chitin  synthase (EC 2.4.1.16).  This enzyme has been well studied in fungi  and yeasts (Gooday 1977)…Leighton e t  al.  (1981)  have  proposed that diflubenzuron  acts indirectly  on  chitin synthase  by inhibiting a  proteolytic enzyme  required for its  activation from  the  zymogen form. http://www.publish.csiro.au/?act=view_file&file_id=BI9820491.pdf

Lufenuron is a benzoylphenylurea drug that interferes with chitin synthesis. It is used in veterinary medicine as a flea prophylactic product, due to its non-specific inhibitory effect on chitin synthesis, probably related to serine protease inhibition.³ http://jfm.sagepub.com/content/11/2/91.full.pdf

OTHER REASONS NOT TO USE CHITIN SYNTHESIS INHIBITORS INCLUDE ITS ABILITY TO AFFECT INTESTINAL MEMBRANES AND FEMALE REPRODUCTION:

An unexpected result of lufenuron treatment was the inhibition of midgut epithelial cell differentiation. At concentrations of 0.5 and 1.0 ppm, partially differentiated epithelial cells were seen in the midgut of blood-fed fleas along with fully differentiated cells. http://www.ncbi.nlm.nih.gov/pubmed/10467778

Micrographs of ovaries, from animals treated with lufenuron, showed some space between the follicular epithelium and the oocyte membrane. The in vivo incorporation of radioactive N-acetylglucosamine into chitin was inhibited by the presence of lufenuron. http://journals2.scholarsportal.info/details.xqy?uri=/00483575/v98i0001/59_te…

Potential Harm

LUFENURON BUILDS UP IN THE TISSUES:

Lufenuron bioaccumulates. http://www.syngenta.co.nz/msds/syngentanz/MATCH_24106015.pdf