Initiation and post-initiation chemopreventive effects of diallyl sulfide in esophageal carcinogenesis.

Diallyl sulfide (DAS), one of a number of organosulfur compounds accounting for the flavor and smell associated with garlic, has been shown to inhibit a number of chemically induced forms of cancer. In this study, DAS was examined for its chemopreventive effects in both the initiation and post-initiation phases of nitrosomethylbenzylamine-induced esophageal carcinogenesis in the Sprague-Dawley rat. Although highly inhibitory during initiation, DAS is ineffective when given after the carcinogen. DAS, though not effective as a preventive in post-initiation, was not found to promote esophageal carcinogenesis.