Hypoxanthine levels in human urine serve as a screening indicator for the plasma total cholesterol and low-density lipoprotein modulation activities of fermented red pepper paste

Fermented red pepper paste (FRPP) is one of the most well-known traditional foods in Korea. The effects of FRPP in experimental animals and adipocytes have been previously reported. However, the biochemical effects have not yet been validated in humans with various genetic backgrounds and environmental factors. In this study, 28 female volunteers (body mass index, more than 23 kg/m²) aged 19 to 60 years were treated with either FRPP or a placebo for 12 weeks. Marked cholesterol modulation was observed in the FRPP-treated group compared with the placebo group. Although the baseline (pretreatment) total cholesterol and low-density lipoprotein levels and body mass index of the volunteers did not differ significantly between the placebo- and FRPP-treated groups, FRPP caused a modulation of cholesterol levels not seen in the placebo group, causing either no variation or a decrease in low-density lipoprotein and total cholesterol levels. Thus, urinary metabolomic profiling of pretreatment samples was carried out in these 2 FRPP-treated groups using ¹H-nuclear magnetic resonance-based metabolomic techniques. These 2 groups, with their opposing cholesterol-modulation tendencies, could be clearly differentiated by orthogonal projections to latent structures-discriminant analysis-derived score plots. In addition, their levels of hypoxanthine differed markedly. We propose that urinary hypoxanthine levels can be used as a screening biomarker to predict the efficacy of the cholesterol-modulating activity of FRPP in human subjects.