Plant Hormones, Gibberellins and Abscissins, and Their Potential Effects on Mammalian Species

Abstract

Attention is drawn to the need for detailed studies in mammalian systems, in vitro and in vivo, of the 'natural' substances which play a role in the regulation of plant growth, known as 'plant hormones'. Among the latter, certain gibberellins, which are growth promoters (GAj), appear to have oestrogenic and carcinogenic action in experimental rodents. Abscisic acid (ABA), which acts as an antagonist of GAj, and induces 'dwarjing', senescence, leaf and fruit drop in plants, has as yet not been tested for anti-oestrogenic, or anti-carcinogenic action in mammals, though it was synthesized 30 years ago. The recent jinding that fruits and vegetables appear to prevent andlor inhibit neoplasias in humans, as do certain isolated constituents of plants (though at relatively high concentrations), indicates the urgent need to evaluate the potential of ABA as a therapeutic agent. Moreover, as ABA has very high 'hormonal' activity in plants, its adventitious presence in preparations and substances isolated from plants has to be considered. Keywords: plant hormones, gibberellin A3-plant growth promoter, potential oestrogen and carcinogen, abscisic acid, antagonist of the action of gibberellin A?. 11 I] Ip C, Lisk DJ, Scimeca JA. Potential of food modification in cancer prevention. Cancer Res 1994; 54: 1957s-1959s. J Nutr Environ Med Downloaded from informahealthcare.com by McMaster University on 12/01/14 For personal use only.