INHIBITORY EFFECTS OF CURCUMIN-FREE AQUEOUS TURMERIC EXTRACT ON BENZO[A]PYRENE-INDUCED FORESTOMACH PAPILLOMAS IN MICE

The modulating effects of curcumin-free aqueous turmeric extract (CFAT E), ethanolic turmeric extract (ETE) and turmeric (T) powder on the be nzo(a)pyrene (B(a)P)-induced forestomach tumors were investigated in S wiss female albino mice receiving oral administration of B(a)P at a do se of 1 mg twice weekly for 4 weeks, Administration of 0.2%/1.0%/5.0% turmeric-derived CFATE as sole source of drinking water or 0.01%/0.05% /0.25% ETE in diet or 0.2%/1.0%/5.0% T in diet, 2 weeks before, during and 2 weeks after the last dose of B(a)P (during initiation period) r esulted in significant suppression of B(a)P-induced tumorigenesis when compared with the group receiving B(n)P and control diet/drinking wat er. Among different fractions tested, CFATE appears to be more powerfu l as not only did it reduce the tumor multiplicity to the lowest level s but it also significantly reduced the tumor incidence, Administratio n of 5.0% turmeric-derived CFATE as the sole source of drinking water or 0.25% ETE/5.0% T in diet starting from 48 h after the last dose of B(n)P (during the post-initiation period) until the termination of the experiment, also inhibited the formation of multiple gastric tumors b y B(a)P, although the suppression of tumor multiplicity was appreciabl y more in the groups that received 5.0% turmeric-derived CFATE/0.25% E TE treatment during initiation with carcinogen, i.e. 2 weeks before, d uring and 2 weeks after the last dose of B(n)P. The present data clear ly indicate the potential of turmeric-derived CFATE as a powerful chem opreventive fraction and also demonstrate the efficacy of lower, i.e. 1/25th and/or 1/5th of the reported, chemopreventive doses of T/ETE (e ssentially curcumins) in inhibiting B(a)P-induced forestomach tumors i n mice. (C) 1997 Elsevier Science Ireland Ltd.