CHEMOPREVENTIVE EFFICACY OF CURCUMIN-FREE AQUEOUS TURMERIC EXTRACT IN7,12-DIMETHYLBENZ[A]ANTHRACENE-INDUCED RAT MAMMARY TUMORIGENESIS

The modulating effects of turmeric (T), ethanolic turmeric extract (ET E) and curcumin-free aqueous turmeric extract (CFATE) on the initiatio n or post-initiation phases of DMBA-induced mammary tumorigenesis were investigated in female Sprague-Dawley rats. Dietary administration of 1% T/0.05% ETE 2 weeks before, on the day of DMBA treatment (day 55) and 2 weeks after the single dose (15 mg/animal) of DMBA (during the i nitiation period) resulted in significant suppression of DMBA-induced mammary tumorigenesis as seen by a reduction in tumor multiplicity, tu mor burden and tumor incidence. However, simultaneous administration o f 1% T-derived CFATE as the sole source of drinking water during the i nitiation phase did not suppress DMBA-induced mammary tumorigenesis. D ietary administration of 1% T/0.05% ETE or 1% T-derived CFATE as the s ole source of drinking water starting 48 h after DMBA treatment and co ntinuing until the end of the experiment (during the post-initiation p eriod) resulted in significant suppression of DMBA-induced mammary tum origenesis as seen by reduction in the tumor multiplicity and/or tumor burden although tumor incidence was unaffected. The present data clea rly indicate that dietary administration of T/ETE showed strong chemop reventive activity during initiation as well as postinitiation phases of DMBA-induced rat mammary tumorigenesis while CFATE was found to be weakly active only when it was administered during the post-initiation phase. (C) 1998 Elsevier Science Ireland Ltd.