title: The in vitro anthelmintic effects of plumbagin on newly excysted and 4-weeks-old juvenile parasites of Fasciola gigantica.
abstract: The effect of plumbagin (PB, 5-hydroxy-2-methyl-1,4-naphthoquinone) against newly excysted juveniles (NEJs) and 4-weeks-old immature parasites of Fasciola gigantica were compared with triclabendazole (TCZ). The anthelmintic efficacy of 1, 10 and 100μg/ml of PB or TCZ following incubation in vitro for 1-24h was compared using a combination of relative motility (RM), survival index (SI) and larval migration inhibition (LMI) assays for parasite viability. The RM and SI values of the PB-treated group decreased at a more rapid rate than the TCZ-treated group. For NEJs, the decreased RM values were first observed at 1h incubation with 1μg/ml PB, and 90% of flukes were killed at 24h. In contrast, in TCZ-treated groups a 10-fold higher concentration of TCZ (10μg/ml) resulted in only 9% dead parasites after 24h incubation. In 4-weeks-old juvenile parasites, PB reduced the RM value at 10μg/ml with 100% of flukes dead after 3h, while TCZ decreased RM values at the concentration of 100μg/ml but with only 5% of flukes killed at 24h. NEJs treated with PB exhibited 88%, 99% and 100% of LMIs at the concentrations of 1, 10 and 100μg/ml, respectively. NEJs incubated with TCZ have an LMI of only 32% at the highest concentration of 100μg/ml. Similarly PB had a significantly greater killing of immature 4weeks juvenile stages than TCZ at all concentrations; however, 4-weeks-old juvenile parasites were more resistant to killing by PB or TCZ at all concentrations when compared to NEJs. Further studies were carried out to investigate the alterations of the parasite tegument by scanning electron microscope (SEM). PB caused similar tegumental alterations in 4-weeks-old juveniles as those observed in TCZ treatment but with greater damage at comparative time points, comprising of swelling, blebbing and rupture of the tegument, loss of spines, and eventual erosion, lesion and desquamation of the total tegument. These data indicate that PB had a greater fasciolicidal effect against immature stages of F. gigantica parasites than TCZ and warrant further studies for use as a potential new anthelmintic against Fasciola infections.
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand. Electronic address: natcha.lor@gmail.com.
authors.forename: Natcha
authors.initials: N
authors.lastname: Lorsuwannarat
authors.affiliation: School of Applied Sciences and Engineering, Monash University, Churchill, Victoria 3842, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Piedrafita
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand.
authors.forename: Pathanin
authors.initials: P
authors.lastname: Chantree
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand.
authors.forename: Veerawat
authors.initials: V
authors.lastname: Sansri
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand.
authors.forename: Sineenart
authors.initials: S
authors.lastname: Songkoomkrong
authors.affiliation: Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Ratchawithi Road, Ratchathewi, Bangkok 10400, Thailand.
authors.forename: Sirasate
authors.initials: S
authors.lastname: Bantuchai
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand.
authors.forename: Kant
authors.initials: K
authors.lastname: Sangpairot
authors.affiliation: Department of Pathobiology, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand(d).
authors.forename: Pornanan
authors.initials: P
authors.lastname: Kueakhai
authors.affiliation: Department of Pathobiology, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand(d).
authors.forename: Narin
authors.initials: N
authors.lastname: Changklungmoa
authors.affiliation: Faculty of Veterinary Medicine, Mahanakorn University of Technology, 140 Cheum-Sampan Road, Nong Chok, Bangkok 10530, Thailand.
authors.forename: Pannigan
authors.initials: P
authors.lastname: Chaichanasak
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand.
authors.forename: Piyachat
authors.initials: P
authors.lastname: Chansela
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand. Electronic address: prasert.sob@mahidol.ac.th.
authors.forename: Prasert
authors.initials: P
authors.lastname: Sobhon
mesh_terms: D000818:Animals; D000980:Antiplatyhelmintic Agents / Q000494:pharmacology*; D001562:Benzimidazoles / Q000494:pharmacology; D002020:Buffaloes; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology; D005209:Fasciola / Q000187:drug effects* / Q000648:ultrastructure; D005211:Fascioliasis / Q000469:parasitology / Q000662:veterinary; D005260:Female; D020128:Inhibitory Concentration 50; D008195:Lymnaea; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008855:Microscopy, Electron, Scanning; D009285:Naphthoquinones / Q000494:pharmacology*; D011897:Random Allocation; D000077682:Triclabendazole
chemical_list: D000980:Antiplatyhelmintic Agents; D001562:Benzimidazoles; D009285:Naphthoquinones; D000077682:Triclabendazole; C014758:plumbagin
keywords: 5-hydroxy-2-methyl-1,4-naphthoquinone; Anthelmintic; DMSO; Fasciola gigantica; Juvenile; NEJ; PB; Plumbagin; TCZ; dimethyl sulphoxide; newly excysted juvenile; triclabendazole