Aristolochic acid (AA), used as an anti-inflammatory agent in the past
, is known to be mutagenic and carcinogenic to several organs of the r
at, including forestomach, renal pelvis and urinary bladder. However,
despite the induction of DNA adducts in the liver, no carcinogenic pot
ential of AA has been reported in the latter organ. The present study
was based on the rationale that the lack of carcinogenicity of AA to t
he liver could be because this chemical may not be necrogenic at the d
oses examined and liver cell proliferation has been established as an
essential component for initiation of liver carcinogenesis in the rat.
The results indicated that AA is non-necrogenic to the rat liver. How
ever, a single non-necrogenic dose of AA (10 mg/kg b.w., i.p.) given 1
8 hours after 2/3 partial hepatectomy initiated liver cell carcinogene
sis. The initiated cells are promotable with 1% dietary orotic acid, a
liver tumor promoter, to form glutathione-S-transferase 7-7 positive
hepatic foci and nodules.