Antitumor-promoting activity of garlic extracts.

Garlic extract was proved to inhibit one of the earliest phenomena caused by 12-O-tetradecanoyl-phorbol-13-acetate (TPA), a tumor promoter, in vitro; i.e., the enhancement of phospholipid metabolism. And also the first stage of tumor promotion in two-stage mouse skin carcinogenesis in vivo was suppressed by the treatment with garlic extract. Thus, garlic extract seems to be effective to inhibit initial events caused by TPA type tumor promoters in vitro and in vivo.