Effects of wood creosote on anisakiasis: A Japanese traditional medicine as a potential tool against Anisakis larva infection

Anisakiasis has become more widely known because of the increasing popularity of raw fish consumption worldwide; it is the most common form of food poisoning in Japan. This foodborne disease has no specific treatment. Current treatments involve detecting and removing parasites that penetrate the gastric mucosa using endoscopy in medical settings. The aim of this study was to investigate the effect of wood creosote (WC) on anisakid larval movement and viability in vitro and in vivo. Using two WC concentrations, 0.67 and 6.7 mg/mL, we performed in vitro and in vivo experiments to demonstrate the effect of WC on anisakid larval movement and viability using an infrared locomotion track device and a viability scoring method. In vitro, WC effectively reduced the motility of anisakid larvae by 69.3 % at a recommended dosage of 0.67 mg/mL and killed the larvae at a higher concentration of 6.7 mg/mL. These results were supported by an in vivo experiment in BALB/c mice, in which WC, at both concentrations, reduced the motility of anisakid larvae in infected mice by more than 58.0 %. WC may become an important tool in treating anisakiasis, owing to its rapid and significant inhibitory effect on the movement and viability of anisakid larvae.