Glycine conjugate detoxification profiling with sodium benzoate loading tests in a selected population of the North-West University

Abstract

The glycine conjugation system is an essential detoxification system needed to detoxify a variety of xenobiotics, including sodium benzoate, a very commonly used preservative. Recently more than 100 single nucleotide polymorphisms (SNP's) have been identified in the glycine N-acyltransferase enzyme system. These were identified during genetic research and none have been linked to a medical condition, although it may have a drastic effect on a person's detoxification and general health. No previous studies have been done to identify possible individuals with deficiencies in this system and possible complications due to such defects. The aim of this study was to determine glycine conjugation profiles of selected test groups after sodium benzoate loading tests, and to identify, according to our own classification, possible slow, medium and fast metabolizers. Hippuric acid, glycine, benzoylcarnitine and benzoic acid excretion in urine were monitored for 12 hours after the loading tests and an excretion profile for each test subject were obtained. A mean hippuric acid excretion curve was also obtained for every loading test and compared to that of the test persons. After the comparison possible slow, medium and fast metabolizers were identified which showed that there does indeed exists detectable variation in glycine conjugation efficiency. This opens a lot of possibilities for future research.