Metabolomic analysis of serum from rats following long-term intake of Chinese sausage

Abstract

IntroductionOwing to the contamination of chemical pollutants, especially nitrosamines and their precursors, in Chinese sausage, long-term intake of Chinese sausage may have potential health effects.ObjectionThis study investigated the effects of long-term intake of Chinese sausage with different contaminations of N-nitrosodimethylamine (NDMA) on rat liver and the potential biomarkers in the serum.MethodsSerum metabolomic analysis was performed by gas chromatography–mass spectrometry at weeks 7, 17, 25, and 33; simultaneously, liver histopathological examination was conducted and its relationship with the serum metabolomics was also investigated.ResultsIn the study, long-term intake of Chinese sausage with different NDMA contents induced significant changes in serum metabolites and liver histopathology in rats. Metabonomic analysis showed that seven metabolites – β-alanine, 3-aminoisobutyric acid, aminooxyacetic acid, D-alanyl-D-alanine, pelargonic acid, palmitic acid (PA), and linoleic acid (LA) – in three sausage diet groups were significantly decreased at four time points, where three other metabolites were notably increased, which included putrescine, ethanolamine phosphate, and taurine. Among the various treatments, the NDMA (sausage-free) group demonstrated the most remarkable changes. Phenylalanine was decreased followed by an increase, and tyrosine persistently declined, both of which were elevated in the NDMA group. In addition, the histopathological result was consistent with that of the serum metabolomic analysis, and the changes in serum metabolites in each sausage diet group and the NDMA group were consistently associated with disorders of lipids, amino acid, and energy metabolism.ConclusionThis work indicates that excessive NDMA content in sausage may cause liver damage.

Effects of vitamin C supplementation on Chinese sausage-induced liver damage in rats

“…Samples were analysed based on a gas chromatograph system (Agilent J&W Scientific, Folsom, CA, California, USA, model 7890B) coupled with a mass selective detector (Agilent, model 5977A), exactly in accordance to our recent descriptions (Rong et al, 2018b).…”

“…According to the data described in our previous report, (Rong et al, 2018a), eight rats from each group (n = 8) were randomly selected in the 7th, 17th and 25th week after treatment, and anesthetised with chloral hydrate via intraperitoneal injection. The blood samples were collected from the aorta abdominalis before the rats were sacrificed.…”

“…Many epidemiological studies indicate that consumption of processed meats is associated with increased risk of esophageal, gastrointestinal, nasopharyngeal and pancreatic tumours, as well as liver damage (IARC, 2018;Zhao et al, 2020). Previously, we have observed that the intake of sausage contaminated with N-nitrosodimethylamine (NDMA) at excessive levels may induce liver damage (Rong et al, 2018a). The hepatotoxicity of the Chinese sausages might be attributed to some toxic substances, such as nitrosamine compounds, aldehydes and ketones in the animal-based pickled foods may also be causative (Lee, 2019).…”

“…Chinese sausage is the commonest salted meat for Chinese residents to consume, however, the contamination of nitrosamines and their precursors (nitrate, nitrite, etc. ) in Chinese sausage and their adverse health effects have become significant public concerns (Li et al, 2021;Rong et al, 2018b). Chinese sausage-induced and Takebayashi, 2021).…”