Polystyrene nanobeads exacerbate chronic colitis in mice involving in oxidative stress and hepatic lipid metabolism.

BACKGROUND: Nanoplastics (NPs) are omnipresent in our lives as a new type of pollution with a tiny size. It can enter organisms from the environment, accumulate in the body, and be passed down the food chain. Inflammatory bowel disease (IBD) is a nonspecific intestinal inflammatory disease that is recurrent and prevalent in the population. Given that the intestinal features of colitis may affect the behavior and toxicity of NPs, it is imperative to clarify the risk and toxicity mechanisms of NPs in colitis models. METHODS AND RESULTS: In this study, mice were subjected to three cycles of 5-day dextran sulfate sodium (DSS) exposures, with a break of 7 to 11 days between each cycle. After the first cycle of DSS exposure, the mice were fed gavagely with water containing 100 nm polystyrene nanobeads (PS-NPs, at concentrations of 1 mg/kg·BW, 5 mg/kg·BW and 25 mg/kg·BW, respectively) for 28 consecutive days. The results demonstrated that cyclic administration of DSS induced chronic inflammation in mice, while the standard drug "5-aminosalicylic acid (5-ASA)" treatment partially improved colitis manifestations. PS-NPs exacerbated intestinal inflammation in mice with chronic colitis by activating the MAPK signaling pathway. Furthermore, PS-NPs aggravated inflammation, oxidative stress, as well as hepatic lipid metabolism disturbance in the liver of mice with chronic colitis. CONCLUSION: PS-NPs exacerbate intestinal inflammation and injury in mice with chronic colitis. This finding highlights chronically ill populations' susceptibility to environmental hazards, which urgent more research and risk assessment studies.

Polystyrene microplastics with absorbed nonylphenol induce intestinal dysfunction in human Caco-2 cells.

Due to the massive production and use of plastic, the chronic and evolving exposure to microplastics in our daily lives is omnipresent. Nonylphenol (NP), a persistent organic pollutant, may change toxicity when it co-exists with microplastics. In this study, polystyrene microplastics (PS-MPs), either alone or with pre-absorbed NP, generated oxidative stress and inflammatory lesions to Caco-2 cells, as well as affecting proliferation via the MAPK signaling pathway and causing apoptosis. Damage to cell membrane integrity and intestinal barrier (marked by lower transepithelial electric resistance, greater bypass transport, and tight junction structural changes) leads to enhanced internalization risk of PS-MPs. Some important intestinal functions including nutrient absorption and xenobiotic protection were also harmed. It is worth noting that the exposure of PS-MPs with a diameter of 0.1 µm improved intestinal functions quickly but acted as a chemosensitizer for a long time, inhibiting cell perception of other toxic substances and making the cells more vulnerable.

Polysaccharides from Eucommia ulmoides Oliv. leaves alleviates alcohol-induced mouse brain injury and BV-2 microglial dysfunction.

Acute alcohol intoxication is a harmful clinical condition characterized by behavioral and neurological symptoms, for which few effective therapies are available at present. Dysfunction of microglial BV-2 cells has been reported to be associated with acute alcohol-induced brain injuries. In the present study, the protective effects of Eucommia ulmoides Oliv. leaves polysaccharides (EULP) on acute alcoholic brain injury and microglial dysfunction were investigated. 14-day pretreatment of EULP significantly attenuated neurobehavioral deficit and neurotransmitter damage in the brain tissue of mice caused by acute alcohol exposure. Additionally, EULP regulated the metabolic disorder of brain tissue. Consistently, it was shown that EULP pretreatment significantly improved alcohol-induced phagocytosis decrease, oxidative stress and inflammation in BV-2 cells. Therefore, EULP may be proposed and employed as a potential therapeutic agent for alcohol-induced brain damage.

Polysaccharides from Eucommia ulmoides Oliv. Leaves Alleviate Acute Alcoholic Liver Injury by Modulating the Microbiota-Gut-Liver Axis in Mice.

The interplay among gut microbiota, intestines, and liver is crucial in preventing acute alcoholic liver injury. In this study, the hepatoprotective potential of polysaccharides from Eucommia ulmoides Oliv. leaves (EULP) on acute alcoholic liver injury in Kunming male mice was investigated. The structural features suggested that the EULP appeared as a heterogeneous mixture of polysaccharides with a molecular weight of 186132 Da. A 14-day pretreatment of EULP ameliorated acute alcoholic-induced hepatic inflam mation (TNF-α, IL-6, and IL-10), oxidative stress (GSH, SOD, and T-AOC), and liver damage (ALT and AST) via enhancing intestinal barrier (Occludin, Claudin 1, and ZO-1) and modulating microbiome, which subsequently inhibiting endotoxemia and balancing the homeostasis of the gut-liver axis. EULP restored the composition of intestinal flora with an increase in the relative abundance of Lactobacillaceae and a decrease in Lachnospiraceae and Verrucomicrobiaceae. Notably, prolonged EULP pretreatment (14 days) but no single gavage of EULP achieved excellent hepatoprotection. These findings endorsed the potential of EULP as a functional food for mitigating acute alcoholic-induce d liver damage, attributed to its anti-inflammatory, antioxidant, and prebiotic properties facilitated by the microbiota-gut-liver axis.

Hyperspectral imaging combined with blood oxygen saturation for in vivo analysis of small intestinal necrosis tissue.

Acute mesenteric ischemia (AMI) is a clinically significant vascular and gastrointestinal condition, which is closely related to the blood supply of the small intestine. Unfortunately, it is still challenging to properly discriminate small intestinal tissues with different degrees of ischemia. In this study, hyperspectral imaging (HSI) was used to construct pseudo-color images of oxygen saturation about small intestinal tissues and to discriminate different degrees of ischemia. First, several small intestine tissue models of New Zealand white rabbits were prepared and collected their hyperspectral data. Then, a set of isosbestic points were used to linearly transform the measurement data twice to match the reference spectra of oxyhemoglobin and deoxyhemoglobin, respectively. The oxygen saturation was measured at the characteristic peak band of oxyhemoglobin (560 nm). Ultimately, using the oxygenated hemoglobin reflectance spectrum as the benchmark, we obtained the relative amount of median oxygen saturation in normal tissues was 70.0 %, the IQR was 10.1 %, the relative amount of median oxygen saturation in ischemic tissues was 49.6 %, and the IQR was 14.6 %. The results demonstrate that HSI combined with the oxygen saturation computation method can efficiently differentiate between normal and ischemic regions of the small intestinal tissues. This technique provides a powerful support for internist to discriminate small bowel tissues with different degrees of ischemia, and also provides a new way of thinking for the diagnosis of AMI.