Pon1 Gene Polymorphism and Serum Paraoxonase Levels in Women Occupationally Exposed to Organophosphate Pesticides in South India.

Abstract

Introduction and Objective:-Paraoxonase (PON1) enzyme detoxifies organophosphates (OPs) by cleavage of active oxons. PON1L55M and PON1Q192R gene polymorphisms affect the enzyme activity and increase susceptibility to OP toxicity. Hence, the present study is aimed to assess the association of serum PON1 levels and PON1 polymorphisms (PON1L55M and PON1Q192R) in women occupationally exposed to organophosphate pesticides. Materials and Methods:-Demographic and occupational data were collected by means of a standard questionnaire from 205 exposed and 212 control subjects belonging to same age, sex and socioeconomic status. Serum paraoxonase levels were analyzed by ELISA kit method. Paraoxonase-1 L55M and Q192R genotype was detected by PCR and RFLP method. Results:-Serum paraoxonase levels were significantly decreased in the exposed group (7.61 ng/mL) when compared to control group (13.09 ng/mL). In PON1 L55M genotype the frequency of the mutant allele 'A' was found to be 27% in exposed and 19 % in controls (OR = 1.64, 95% CI: 1.18-2.27; p =0.003) whereas in PON1 Q192R genotype did not show any statistical significance. Linkage disequilibrium between the variants of PON1 was found to be strong (D′>0.7). Conclusion:-A significant association of serum paraoxonase levels with PON-1 L55M and Q192R gene polymorphisms was observed in women occupationally exposed to OP pesticides. Thus, the study emphasizes the importance of serum PON1 enzyme levels and its association with PON1 gene polymorphisms and serum PON1 enzyme levels can be potential biomarker for OP-susceptible individuals, especially in occupationally exposed populations for risk assessment.