CROCIN AND CROCETIN DERIVATIVES INHIBIT SKIN TUMOR PROMOTION IN MICE

The addition of 100 mu g/mL of a 50% EtOH extract of Crocus sativus (E CS) exhibited significant inhibitory effects on EBV-EA activation and preserved the high viability of Raji cells. The attenuating effect of ECS was dose-dependent. The oral administration of ECS demonstrated an inhibitory effect on two-stage carcinogenesis of mouse skin papilloma s, using DMBA as an initiator and TPA as a promoter. Crocetin gentiobi ose glucose ester and crocetin di-glucose ester were less potent than crocin in inhibiting the EBV-EA induction effect. When crocin was appl ied before each TPA treatment, it delayed the formation of papillomas; only about 10% of mice bore papillomas at 9 weeks of promotion and af ter 13 weeks of promotion 20% of mice still bore no papilloma, The eff ect of crocin was not mimicked by gentiobiose or glucose alone. (C), 1 998 John Wiley SL Sons, Ltd.