Absence of mutagenicity of acid pyrogallol-containing hair gels

In the present work, three commercial acid (pH 3.5–4) pyrogallol-containing hair gels, SunSet® Alizador Negro (two formulations) and Embelleze® Henê Gel, were tested for mutagenicity using two well-established assays. In the Salmonella mutagenicity assay using 648–5000 μg/plate of cosmetic samples, none of the samples reached a 2-fold increase in revertants relative to the controls. Both in the absence and in the presence of S9, the dose–response relation in strains TA98, TA100, TA102, TA1535, and TA1537 was not significant (p > 0.01). In the mouse bone marrow micronucleus assay, 10 Swiss male mice were orally administered 2000 mg/kg of sample per body weight/day. The ratio between polychromatic and normochromatic erythrocytes as well as the presence of micronuclei in bone marrow cells were determined. Equal numbers of micronucleated polychromatic erythrocytes were detected between the cells of each treated group and the negative control, using ANOVA and χ-square analyses. Thus, none of the products induced mutagenesis in either assay. Previous studies have shown pyrogallol is mutagenic in various test systems, including Salmonella. However studies have also shown that acidic conditions may repress the reactive-oxygen species (ROS) produced by pyrogallol, and ROS is considered the primary mechanism for the mutagenicity of pyrogallol. Consistent with this are our results, which show that acidic, commercially available pyrogallol-containing hair gels are neither mutagenic in Salmonella nor induce micronuclei in mouse bone marrow in vivo.