Metabolomics reveals the toxicological effects of polar compounds from frying palm oil

Abstract Polar compounds from frying oil have been found to be harmful to health. However, the mechanisms underlying this phenomenon have largely remained elusive. In this study, mass spectrometry-based metabolomics was used to investigate the toxicological effects of polar compounds. Serum and hepatic metabolites from polar compounds treated mice were measured using liquid chromatography–mass spectrometry and gas chromatography–mass spectrometry. Multi-variate statistical analysis showed a total of 36 serum metabolites and 18 hepatic metabolites are altered in polar compounds treated mice as compared with normal diet-fed animals. These metabolic changes suggested novel alterations of lipid metabolism, with increase of phospholipids, fatty acids, cholesterol and decrease of choline, betaine and L-acetylcarnitine. The TCA cycle, carbohydrate, amino acid and purine metabolism was also impaired with significant elevation of D-glucose, D-maltose, β-mannobiose, branched chain amino acid, aromatic amino acid, and uric acid and decline of succinate, serine, aspartate, arginine and ornithine. Pearson correlation analysis demonstrated the strong correlations between specific metabolic alterations with redox index. Our overall finding reveals polar compounds may progressively cause lipid deposition, impaired energy metabolism and oxidative stress, resulting in toxicological effects on mammal health.