A probe into the possible mechanism underlying the interceptive action of aristolic acid.

Oral administration of aristolic acid (90 mg/kg body weight) on day 6 pregnant and pseudopregnant mice resulted in the termination of pregnancy with in utero fetal death but the length of pseudopregnancy remained unaffected. Peripheral level of progesterone remained statistically uninfluenced in both conditions and exogenous progesterone failed to prevent aristolic acid-induced pregnancy loss, both of which rule out the involvement of luteolysis as the causal factor for the termination of pregnancy. In another experiment, aristolic acid was found to have no inhibitory effect over the maintenance of decidual cell reaction which indicates no inhibitory influence of the compound on uterine utilization of progesterone but points to the fact that presence of concepts is an essential component in the array of mechanism(s) leading to the termination of pregnancy. Probable toxic effect of aristolic acid on the concepts is discussed.