PON1, short for paraoxonase 1, is a high-density lipoprotein-associated enzyme with antioxidant, anti-inflammatory, and anti-apoptotic roles [6]. One of its most important enzymatic activities in association with high-density lipoprotein (HDL) is the prevention of low-density lipoprotein (LDL) oxidation, giving it an anti-atherogenic activity [2]. It is also involved in the detoxification of organophosphate insecticides [3,7].

PON1 gene polymorphisms have been widely studied. The PON1 L55M polymorphism might increase the risk of cancer, especially breast cancer in certain populations, and the PON1 Q192R and L55M polymorphisms may increase the risk of organophosphate toxicity, particularly among Caucasian populations [1,3]. In addition, the PON1 Q192R polymorphism has a weak association with coronary heart disease risk in Chinese [8]. Liver disease significantly reduces PON1 activity, and the gene polymorphism is associated with an increased risk of liver disease [4]. In idiopathic inflammatory myopathies, the arylesterase and lactonase activities of PON1 are significantly impaired and inversely associate with disease activity [5].

In conclusion, PON1 is crucial for maintaining normal physiological functions, especially in lipid metabolism, detoxification, and protection against oxidative stress. Its gene polymorphisms are associated with various diseases such as cancer, organophosphate toxicity-related conditions, coronary heart disease, liver disease, and idiopathic inflammatory myopathies. Research on PON1 helps in understanding disease mechanisms and may offer potential for targeted therapies.