In vitro testing for genotoxicity of indigo naturalis assessed by micronucleus test.
In the field of cosmetic dyes, used for coloring the hair and skin, there is a clear tendency to replace the widely used synthetic dyes by natural colorants, such as henna and mixtures of henna with indigo. The aim of this study was to estimate the genotoxicity of water and DMSO solutions of indigo naturalis (prepared from Indigofera tinctoria leaves) using the cytokinesis-blocked micronucleus (CBMN) assay in the human metabolically active HepG2 cell line. The cytotoxic effects of indigo solutions were first assessed by propidium iodide and fluorescein-diacetate simultaneous staining. For both solutions, cytotoxicity was always under 10%. Data obtained in the CBMN assay (for all concentrations tested) indicated that the frequency of MN (micronuclei) in exposed cells was no higher than the control. Both the water and DMSO solutions showed the same behavior. These results indicate that indigo naturalis exhibits neither cytotoxicity, nor genotoxicity for all concentrations tested, which may justify excluding indigofera and its components from the list of carcinogenic agents.
Dominici
Luca
L
Department of Medical-Surgical Specialties and Public Health (Section of Public Health), University of Perugia, Perugia, Italy.
Cerbone
Barbara
B
Villarini
Milena
M
Fatigoni
Cristina
C
Moretti
Massimo
M
D002470:Cell Survival / Q000187:drug effects; D004396:Coloring Agents / Q000633:toxicity*; D056945:Hep G2 Cells; D006801:Humans; D029883:Indigofera / Q000737:chemistry*; D015162:Micronucleus Tests / Q000379:methods*; D010936:Plant Extracts / Q000633:toxicity*
D004396:Coloring Agents; D010936:Plant Extracts