[Inhibition of ornithine decarboxylase activity and epidermal papilloma in mice by beta-carotene].

Anticarcinogenic action of beta-carotene was analyzed with determination of ornithine decarboxylase (ODC) activity induced by TPA and a two-stage model of skin papilloma-genesis in mice. Results showed increase of ODC activity induced by TPA could be significantly inhibited, onset of tumor postponed, and number of tumor foci decreased by beta-carotene. It suggested beta-carotene had an obvious chemoprophylactic effect on tumor.