Enzymatic activity induction of GST-family isoenzymes from pesticide mixture used in floriculture.

Glutathione S-transferases (GSTs) comprise a number of genes that codify for a group of isoenzymes that participate in phase II xenobiotic detoxification by means of conjugation with glutathione, producing hydrosoluble compounds. It has been demonstrated that some pesticides are substrates for GST isoenzymes. Floriculture is one of the main economic activities in the municipalities of Villa Guerrero and Atlacomulco; pesticides, applied as mixtures, are intensively used in this activity. In this study, total GST enzymatic activity and glutathione S-transferases theta 1 (GSTT1) enzymatic activity were calculated for a group of floriculture workers exposed to pesticides and for an unexposed group. The former comprised 169 floriculture workers, while the latter, 96 students. The value of the median GST enzymatic activity in the exposed group was 0.560 and 0.169 μmol/min/mL in the unexposed individuals. GSTT1 activity was 1.234 μmol/min/mL in the exposed group and 0.221 μmol/min/mL in the unexposed group. Mann-Whitney U test showed a significant difference between these groups, for both total GST and GSTT1, p < 0.001. Our results show that exposure to pesticides increases the activities of total GST and GSTT1 enzymes.