GSTM1, GSTT1, and GSTP1 Polymorphism in North Indian Population and its Influence on the Hydroquinone-Induced In Vitro Genotoxicity

Abstract

Glutathione S transferase (GST) gene polymorphism examined among north Indians and correlated with hydroquinone (HQ) genotoxicity to help in clinical prediction of susceptibility of HQ toxicity. Lymphocytes of individuals with/without GSTM1, GSTT1, and GSTP1 (ile/ile or val/val) were exposed to HQ (20, 40, or 80 μM) and examined chromosomal aberrations (CA) or cytokinesis-block micronucleus assays. Among north Indians the frequencies of GSTM1 (null), GSTT1 (null), and both null were found to be 41.1, 21.9, and 12.7%, whereas frequencies of GSTP1 with (ile/ile) or (ile/val), or (val/val) were 52, 42.1, or 5.9%, respectively. Individuals with null GSTM1, GSTT1, and GSTP1 (val/val) showed inhibition of mitotic index (MI) and significant (p < 0.01) induction of CA as compared to individuals with GSTM1, GSTT1, and GSTP1 (ile/ile). Micronucleus formation was found to be significant (p < 0.05 or 0.01) in both the genotypes. Results indicate that GSTM1, GSTT1 (null), and GSTP1 (val/val) are sensitive to HQ genotoxicity.

KEYWORDS:

• Hydroquinone
• Genetic polymorphism
• Glutathione-S-transferase
• Chromosome aberrations
• Micronucleus induction

The authors thank Director, IITR (CSIR) for continuous interest and support for the study. The authors also acknowledge the technical assistance of Mr Sitaram, Mr Ram Surat, and Mrs Mumtaj Jahan. Mr Munish Kumar is thankful to ICMR, New Delhi, for the fellowship grant to conduct this study.