title: The in vitro effect of albendazole, ivermectin, diethylcarbamazine, and their combinations against infective third-stage larvae of nocturnally subperiodic Brugia malayi (Narathiwat strain): scanning electron microscopy.
abstract: Scanning electron microscopy (SEM) was employed to observe the effects of ivermectin (IVM), diethylcarbamazine (DEC), and albendazole (ALB) alone, and the drugs in combination (ALB+IVM and ALB+DEC) against infective third stage larvae (L3) of nocturnally subperiodic (NSP) Brugia malayi (Narathiwat strain) in vitro. IVM, at a concentration of 10(-4) M, killed L3 within 1-2 h. The SEM data showed damage to the L3 surface and loss of regular cuticular annulations. The cuticles were grooved in the middle region of the body. In comparison with normal L3 before treatment with IVM, the cuticular surface showed transversed striations with periodic annulations. The result demonstrated that IVM showed a larvicidal activity against L3 of NSP B. malayi cultivated in vitro. Compared with those larvae in the control group, the treated larvae had no morphological changes in the cuticular surface at the head, body, and tail regions after cultivation with all drugs alone, and in their combinations at a concentration of 10(-5) M for 7 d. In this system, and at that concentration, only the larvae cultured with ALB alone remained highly motile. Although no morphological changes had been observed by SEM, those drugs used alone (IVM and DEC) and in combinations (ALB+IVM and ALB+DEC), reduced larval motility throughout the experiments at a concentration of 10(-5) M. The minimum lethal concentration (MIC) of IVM against NSP B. malayi was 10(-4) M.
authors.affiliation: Department of Parasitology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
authors.forename: Pongsri
authors.initials: P
authors.lastname: Tippawangkosol
authors.forename: Wej
authors.initials: W
authors.lastname: Choochote
authors.forename: Kesara
authors.initials: K
authors.lastname: Na-Bangchang
authors.forename: Atchariya
authors.initials: A
authors.lastname: Jitpakdi
authors.forename: Benjawan
authors.initials: B
authors.lastname: Pitasawat
authors.forename: Doungrat
authors.initials: D
authors.lastname: Riyong
mesh_terms: D015766:Albendazole; D000818:Animals; D000871:Anthelmintics / Q000633:toxicity*; D000969:Antinematodal Agents / Q000633:toxicity*; D017178:Brugia malayi / Q000472:pathogenicity* / Q000648:ultrastructure*; D002940:Circadian Rhythm; D004049:Diethylcarbamazine / Q000633:toxicity*; D005368:Filariasis; D005369:Filaricides / Q000633:toxicity*; D007559:Ivermectin / Q000633:toxicity*; D007814:Larva / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D009068:Movement; D018675:Toxicity Tests
chemical_list: D000871:Anthelmintics; D000969:Antinematodal Agents; D005369:Filaricides; D007559:Ivermectin; D015766:Albendazole; D004049:Diethylcarbamazine