The acetylcholinesterase (AChE) inhibition of 12 plant-derived insecticidal compounds (anethol, anisaldehyde, 3-carene, 1,8-cineol, ethyl-cinnamate, linalool, magnolol, ethyl-p-methoxycinnamate, p-methoxycinamic acid, safrol, terpinen-4-ol, and α-terpineol) towards adult mosquitoes were examined by using Ellman method. Result were compared with those of dichlorvos, a potent AChE inhibitor. 3-Carene strongly inhibited AChE (IC50, 5.78×10-4 M), although the inhibition of the compound was lower than dichlorvos (IC50, 1.45×10-4 M). These results indicate that 3-carene acts as an AChE inhibitor, although an involvement of other insecticidal mechanism(s) might not be ruled out.

A 67-year-old man visited our hospital with anorexia and abdominal discomfort after taking herb for 3 months. Abdominal computed tomograpy showed splenomegaly. Blood test showed elevation of serum alanine aminotransferase level, thrombocytopenia, and there was no viral or autoimmune hepatitis. Liver biopsy showed comprehensive fibrotic changes and necrosis on iver parenchyma. He recovered within 1 week after stopping the herb. There was no disease recurrence for 1 year. No case of toxic hepatitis by taking Fritillaria thunbergii Miquel has been reported. Thus, this case proved for the first time that Fritillaria thunbergii Miquel could cause drug induced liver injury.