The production, use, and waste of plastics increased worldwide, which resulted in environmental pollution and a growing public health problem. In particular, microplastics have the potential to accumulate in humans and mammals through the food chain. However, the toxicity of microplastics is not well understood. In this study, we investigated the toxicity of 10–50 μm polyethylene microplastics following single- and 28-day repeated oral administration (three different doses of microplastics of 500, 1000, and 2000 mg/kg/day) in ICR mice. For the investigation, we administered the microplastics orally for single- and 28-day repeated. Then, the histological and clinical pathology evaluations of the rodents were performed to evaluation of the toxicity test, and Raman spectroscopy was used to directly confirm the presence of polyethylene microplastics. In the single oral dose toxicity experiments, there were no changes in body weight and necropsy of the microplastics-treated group compared with that of controls. However, a histopathological evaluation revealed that inflammation from foreign bodies was evident in the lung tissue from the 28-day repeated oral dose toxicity group. Moreover, polyethylene microplastics were detected in the lung, stomach, duodenum, ileum, and serum by Raman spectroscopy. Our results corroborated the findings of lung inflammation after repeated oral administration of polyethylene microplastics. This study provides evidence of microplastic-induced toxicity following repeated exposure to mice.

The biological actions of various ginseng extracts have been studied for treating obesity and diabetes mellitus. However, few studies have evaluated the effects of fermented Korean Red Ginseng (Panax ginseng Meyer) on metabolic syndrome. The present study evaluated the antiobesity and antidiabetic effects of fermented red ginseng (FRG) on old-aged, obese, leptin-deficient (B6.V-Lepob, "ob/ob") mice. The animals were divided into three groups and given water containing 0%, 0.5%, and 1.0% FRG for 16 wk. The effect of FRG on ob/ob mice was determined by measuring changes in body weight, levels of blood glucose, serum contents of triglycerides, total cholesterol and free fatty acids, messenger RNA (mRNA) expressions of key factors associated with insulin action, such as insulin receptor (IR), lipoprotein lipase (LPL), glucose transporter 1 and 4 (GLUT1 and GLUT4), peroxisome proliferators-activated receptor gamma (PPAR-γ), and phosphoenolpyruvate carboxykinase (PEPCK) in the liver and in muscle, and histology of the liver and pancreas. FRG-treated mice had decreased body weight and blood glucose levels compared with control ob/ob mice. However, anti-obesity effect of FRG was not evident rather than hypoglycemic effect in old aged ob/ob mice. The hyperlipidemia in control group was attenuated in FRG-treated ob/ob mice. The mRNA expressions of IR, LPL, GLUT1, GLUT4, PPAR-γ, and PEPCK in the liver and in muscle were increased in the FRG-treated groups compared with the control group. These results suggest that FRG may play a vital role in improving insulin sensitivity relative to reducing body weight in old-aged ob/ob mice.

The incidence of ulcerative colitis (UC) is increasing worldwide, and it has become a growing problem in Asia. Previous research on UC has focused on serum, plasma, urine, gut tissues, and fecal metabolic profiling, but a comprehensive investigation into the correlation between the severity of colitis and changes in liver metabolism is still lacking. Since the liver and gut exchange nutrients and metabolites through a complex network, intestinal diseases can affect both the liver and other organs. In the present study, concentration-dependent dextran sodium sulfate (DSS)-induced ulcerative colitis was employed to examine changes in liver metabolism using a proton nuclear magnetic resonance spectroscopy (¹H-NMR)-and ultra-performance liquid chromatography time of flight mass spectroscopy (UPLC-TOF MS)-based metabolomics study. Using the multivariate statistical analysis method orthogonal projections to latent structures discriminant analysis (OPLS-DA), changes in metabolites depending on the DSS dose could be clearly distinguished. Specifically, hepatic metabolites involved in one-carbon metabolism, carnitine-related metabolism, and nucleotide synthesis were found to be affected by intestinal inflammation, implying the existence of a metabolic connection between the gut and liver. We are currently investigating the significance of this metabolic condition in UC.