Mutagenic and Genotoxic Screening of Eight Commonly used Skin Whitening Creams in Nigeria
Skin whitening (bleaching) creams are often used to deliberately lighten the skin in response to social pressures or for the treatment of skin pigmentation. Bleaching creams contain varied concentrations of hydroquinone, corticosteroids, ammoniated mercury and kojic acid. Prolonged use of these creams may have deleterious (mutagenic) effect on the genetic material (DNA) of body cells. The purpose of this study was to evaluate the mutagenicity potentials of eight commonly used bleaching creams (Body white, Tura, Maxitone, Movate, Amos white, Top gel, Ultra clair, Fair and white), using the modified Ames test (with and without metabolic activation) that uses the wild type Escherichia coli (0157:H7) as tester strain. The assay was examined for revertant strains of the organism with at least three alterations in the phenotypic characteristics of the wild type organism. Results obtained showed that the eight bleaching creams produced revertant strains of the organism with alteration in more than three of its phenotypic characteristics and compared favourably with the standard mutagen (ethidium bromide), which produced the same effect. Three mutation mechanisms (forward, backward and silent mutations) were identified. The introduction of liver enzymes (S9 mix) made no significant difference in the number of characteristics altered (p>0.05). The results of this study revealed that the eight bleaching creams were mutagenic in bacteria and could be said to possess carcinogenic potentials. Their mechanism of mutagenesis could also be by intercalation just as ethidium bromide.