Vermox
Interaction of anthelmintic benzimidazoles with Ascaris suum embryonic tubulin.

Friedman PA, Platzer EG.

The ability of mebendazole and fenbendazole to bind to tubulin in cytosolic fractions from 8-day Ascaris suum embryos was determined by inhibition studies with [3H]colchicine. Colchicine binding in the presence of 1 . 10(-6) M mebendazole was completely inhibited during a 6 h incubation period at 37 degrees C. Inhibition of colchicine binding to A. suum embryonic tubulin by mebendazole and fenbendazole appeared to be noncompetitive. The inhibition constants of mebendazole and fenbendazole for A. suum embryonic tubulin were 1.9 . 10(-8) M and 6.5 . 10(-8) M, respectively. Mebendazole and fenbendazole appeared to be competitive inhibitors of colchicine binding to bovine brain tubulin. The inhibition constants of mebendazole and fenbendazole for bovine brain tubulin were 7.3 . 10(-6) M and 1.7 . 10(-5) M, respectively. These values are 250-400 times greater than the inhibition constants of fenbendazole and mebendazole for A. suum embryonic tubulin. Differential binding affinities between nematode tubulin and mammalian tubulin for benzimidazoles may explain the selective toxicity. The importance of tubulin as a receptor for anthelmintic benzimidazoles in animal parasitic nematodes is discussed.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7388055&dopt=Abstract mebendazole Vermox



Vermox
Recovery of larval Hymenolepis diminuta and H. nana from the retardation produced by prolonged exposure to mebendazole in beetles.

Evans WS, Novak M.

Tribolium confusum infected with Hymenolepis diminuta or H. nana were fed continuously on a mixture of mebendazole and flour from day 1 (24 hr) to day 9, 18, 27, or 36 postinfection when they were dissected. In all cases, underdeveloped cysticercoids were recovered from these hosts, whereas all parasites grown simultaneously in beetles fed on flour only had reached full development. However, when infected beetles were fed on the drug-flour mixture for these periods of time and then on flour only for 9 days thereafter, the inhibiting effect of mebendazole was reversed. Parasites retarded by the drug recovered and developed into infective cysticercoids.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7391866&dopt=Abstract mebendazole Vermox



Vermox
Pathogenesis of hepatic septal fibrosis associated with Capillaria hepatica infection of rats.

Santos AB, Tolentino M Jr, Andrade ZA.

Laboratorio de Patologia Experimental, Centro de Pesquisa Goncalo Moniz, Fundacao Oswaldo Cruz, Salvador, BA, Brasil.

Septal fibrosis is a common form of hepatic fibrosis, but its etiology and pathogenesis are poorly understood. Rats infected with the helminth Capillaria hepatica constitute a good experimental model of such fibrosis. To investigate the pathogenetic contribution of the several parasitic factors involved, the following procedures were performed in rats: a) regarding the role of eggs, these were isolated and injected either into the peritoneal cavity or directly into the liver parenchyma; b) for worms alone, 15-day-old infection was treated with mebendazole, killing the parasites before oviposition started; c) for both eggs and worms, rats at the 30th day of infection were treated with either mebendazole or ivermectin. Eggs only originated focal fibrosis from cicatricial granulomas, but no septal fibrosis. Worms alone induced a mild degree of perifocal septal fibrosis. Systematized septal fibrosis of the liver, similar to that observed in the infected controls, occurred only in the rats treated with mebendazole or ivermectin, with dead worms and immature eggs in their livers. Thus, future search for fibrogenic factors associated with C. hepatica infection in rats should consider lesions with both eggs and worms.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11813054&dopt=Abstract mebendazole Vermox



Vermox
Plasma concentrations of mebendazole during treatment of echinococcosis: preliminary results.

Munst GJ, Karlaganis G, Bircher J.

High oral doses of mebendazole are used experimentally for the treatment of human alveolar and cystic echinococcosis. In order to assess bioavailability of this drug 1.5 g doses were given to 3 volunteers. Measurable plasma concentrations of 17 to 134 nmol/l were found only if mebendazole was given together with a fatty meal. In a patient with cholestasis plasma concentrations were higher than in the 3 normal subjects. In patients on long term treatment the increase in plasma concentration after administration of a 1 g dose varied between 0 and 500 nmol/l. It is concluded that systemic availability of mebendazole is enhanced by concomitant food intake. In view of the large intra- and interindividual variation in plasma concentration, monitoring plasma levels during long term therapy appears advisable.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7418715&dopt=Abstract mebendazole Vermox



Vermox
Two high-performance liquid chromatographic determinations for mebendazole and its metabolites in human plasma using a rapid Sep Pak C18 extraction.

Allan RJ, Goodman HT, Watson TR.

A rapid extraction procedure for mebendazole and its metabolites from plasma using Sep Pak C18 is described. This method eliminates the need for solvent extractions as such. Two reversed-phase high-performance liquid chromatographic determinations for these extracts, one isocratic elution and the other gradient elution, using an analytical wavelength of 254 nm are also presented. The gradient elution system provides superior resolution of these compounds and consequently has improved determination limits. For mebendazole the determination limits are 20 ng/ml (isocratic system) and 10 ng/ml (gradient system).

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7419648&dopt=Abstract mebendazole Vermox



Vermox
Human intestinal parasites in Karakuak, West Flores, Indonesia and the effect of treatment with mebendazole and pyrantel pamoate.

Purnomo, Partono F, Soewarta A.

A survey for intestinal parasites and mass-treatment with a combination of mebendazole and pyrantel pamoate were conducted in Karakuak, West Flores in 1977. A total of 198 stool specimens from 104 males and 94 females ranging in age from less than 1 to 70 years were examined and 72% harbored one or more intestinal parasites. Ascaris lumbricoides (43%) and Entamoeba histolytica (21%) were the most common, followed by Entamoeba coli (19%), hookworm (18%), Iodamoeba butschlii (8%), Giardia lamblia (5%) and Trichuris trichiura (4%). Other intestinal parasites infrequently found were: Entamoeba hartmanni (2%), Chilomastix mesnili (2%), Endolimax nana (1%), Enterobius vermicularis (1%) and a heterophyid sp. (1%). A combination of mebendazole base at 200 mg/day and pyrantel pamoate salt at 60 mg/day for three consecutive days was 100% effective.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7444573&dopt=Abstract mebendazole Vermox