Two classes of common phenolic plant pigments, the anthraquinones and the flavonols, contain many members mutagenic in the Salmonella/mammalian microsome assay. Several reports on the mutagenicity or other genetic or “carcinogenic” effects of these compounds have appeared in the literature or have been presented at various scientific meetings. The object of this review paper is to assess the present state of knowledge with respect to the genetic toxicity of these agents and their dietary intake and metabolic fate in man. Such information is necessary for formulating an assessment of genetic or carcinogenic risk to man posed by these agents.

A review of the genetic effects of naturally occurring flavonoids, anthraquinones and related compounds.

Publisher Summary This chapter discusses chromosome aberrations induced by ionizing radiations. Chromosome aberrations are used as general indices of cellular damage or as cell markers in studying cell-population kinetics in irradiated or tumor tissues. Of primary importance are the mechanisms involved in aberration induction and in the action of modifying agents that alter the overall frequency or relative frequencies of the different aberration types. The types of aberrations that are induced following irradiation or treatment with certain radiomimetic chemicals are classified according to the unit of breakage or exchange that is involved. The types of structural changes that can occur within or between chromosomes and chromatids are of two kinds: the simple deletion and the exchange. The simple deletion appears to be the result of a single break in the chromosome or chromatid and the exchange is a new rearrangement following the joining of breakage ends that result from separate breaks. Comparisons among different types of ionizing radiations and among similar radiation types having different energies for their capacity for producing chromosome aberrations are of considerable fundamental importance in the study of aberration production.

Chromosome Aberrations Induced by Ionizing Radiations

The common onion (Allium cepa) is an excellent plant for the assay of chromosome aberrations after chemical treatment. Other species of allium (A. cepa var. proliferum, A. carinatum, A. fistulosum and A. sativum) have also been used but to a much lesser extent. Protocols have been given for using root tips from either bulbs or seeds of Allium cepa to study the cytological end-points, such as chromosome breaks and exchanges, which follow the testing of chemicals in somatic cells. It is considered that both mitotic and meiotic end-points should be used to a greater extent in assaying the cytogenetic effects of a chemical. From a literature survey, 148 chemicals are tabulated that have been assayed in 164 Allium tests for the clastogenic effect. Of the 164 assays which have been carried out, 75 are reported as giving a positive reaction (i.e., causing chromosome aberrations), 49 positive and with a dose response, 1 positive and temperature-related, 9 borderline positive, and 30 negative; 76% of the chemicals gave a definite positive response. It is proposed that the Allium test be included among those tests routinely used for assessing chromosomal damage induced by chemicals.

Chromosome aberration assays in Allium. A report of the U.S. Environmental Protection Agency Gene-Tox Program.

Recent findings on the genetic toxicology of benzene, toluene, xylenes and phenols

Phenol, a monohydroxy derivative of benzene, occurs naturally in animal waste and by decomposition of organic wastes. It is also produced by man, originally by fractional distillation of coal tar, but more recently by cumene hydroperoxidation and toluene oxi dation. As a result of large production volume and natural sources, occupational and environmental exposure to phenol is likely. Phenol poisoning can occur by skin absorption, vapor inhalation, or ingestion, and, regardless of route of exposure, can result in det rimental health effects. Acute toxicity has been observed in man and experimental animals, resulting in muscle weakness, convul sions, and coma. In addition, studies have shown that although teratogenic effects have not been associated with exposure to phenol by either inhalation or oral route, high doses of phenol are fetotoxic. This paper addresses these studies and others in an attempt to determine if human health is at risk to those levels of phenol present in the environment and workplac...

Joe Hin Tji

Papers

Induction of chromosome fragmentation by phenols