The influence of a standardized soybean extract (Glycine max) on the expression level of CYP3A enzymes and pregnane X receptor in in vivo model

Abstract Objective: Soybean phytoestrogens, such as genistein and daidzein, have become a popular alternative for women undergoing the treatment of menopause symptoms. These isoflavones are also commonly used in traditional medicine in the prevention and treatment of osteoporosis, cardiovascular diseases and cancer. Despite the widespread use of soybean preparations as functional foods and dietary supplements, data regarding the safety as well as interactions between herbal medicines and synthetic drugs, especially with antineoplastic agents, remain scarce. Therefore, the aim of the present study was to determine the influence of soybean extract on the expression levels of CYP3A and PXR genes using real-time PCR (RT-PCR). Materials and methods: Male Wistar rats were given a standardized soybean extract (100mg/kg p.o.) for 3 and 10 days. Total RNA isolated from the liver tissue was transcribed into cDNA. The level of CYP3A1/2 and PXR mRNAs expression was analyzed by real-time quantitative PCR using SYBR Green I dye. Results: Our findings showed that soybean extract containing 37% isoflavones resulted in a significant decrease of CYP3A1 expression level by almost 35% (