Efficacy of Polyethylene Glycol Electrolyte Powder Combined with Linaclotide for Colon Cleansing in Patients with Chronic Constipation undergoing colonoscopy: a Multi-centre, single-blinded, Randomized-Controlled Trial.

BACKGROUND AND AIMS: Constipation is an independent risk factor for poor bowel preparation. This study aimed to evaluate the bowel-cleansing efficacy and safety of polyethylene glycol (PEG) combined with linaclotide (lin) for colonoscopy in patients with chronic constipation. METHODS: This single-blinded, randomized, controlled and multicenter study was conducted from July 2021 to December 2022 at seven hospitals. Patients with chronic constipation who underwent colonoscopies were enrolled and randomly assigned to 4 groups with split -PEG regimens: 4L-PEG group, 4L-PEG+1d-Lin group, 3L-PEG+1d-Lin group, and 3L-PEG+3d-Lin group. The primary outcome was rates of adequate bowel preparation, defined as a total BBPS score ≥6 and a score ≥2 for each segment. Secondary outcomes were adverse effects, sleep quality, willingness to repeat the colonoscopy, adenoma detection rate, and polyp detection rate. RESULTS: 502 patients were enrolled. The rates of adequate bowel preparation (80.0% vs. 60.3%, P<0.001; 84.4% vs. 60.3%, P<0.001) and the total BBPS scores (6.90±1.28 vs. 6.00±1.61, P<0.001; 7.03±1.24 vs. 6.00±1.61, P<0.01) in 4L-PEG+1d-Lin group and 3L-PEG+3d-Lin group were superior to that in 4L-PEG group. Compared with 4L-PEG group, 4L-PEG+1d-Lin group (66.7% vs. 81.7%, P=0.008) and 3L-PEG+3d-Lin group (75.0% vs. 81.7%, P=0.224) had a lower percentage of mild adverse events. No statistically significant difference in willingness to repeat the colonoscopy, sleep quality, polyp detection rate, or adenoma detection rate was observed among groups. CONCLUSIONS: PEG combined with linaclotide might be an effective method for bowel preparation before colonoscopy in patients with chronic constipation.

Losartan attenuates acetic acid enema-induced visceral hypersensitivity by inhibiting the ACE1/Ang II/AT1 receptor axis in enteric glial cells.

Enteric glial cells (EGCs) play an important role in visceral hypersensitivity associated with irritable bowel syndrome (IBS). Losartan (Los) is known to reduce pain; however, its function in IBS is unclear. The present study aimed to investigate Los's therapeutic effect on visceral hypersensitivity in IBS rats. Thirty rats were randomly divided into control, acetic acid enema (AA), AA + Los low, medium and high dose groups in vivo. EGCs were treated with lipopolysaccharide (LPS) and Los in vitro. The molecular mechanisms were explored by assessing the expression of EGC activation markers, pain mediators, inflammatory factors and angiotensin-converting enzyme 1(ACE1)/angiotensin II (Ang II)/Ang II type 1 (AT1) receptor axis molecules in colon tissue and EGCs. The results showed that the rats in the AA group showed significantly higher visceral hypersensitivity than the control rats, which was alleviated by different doses of Los. The expression of GFAP, S100ß, substance P (SP), calcitonin gene-related peptide (CGRP), transient receptor potential vanilloid 1 (TRPV1), tumor necrosis factor (TNF), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) was considerably increased in colonic tissues of AA group rats and LPS-treated EGCs compared with control rats and EGCs, and reduced by Los. In addition, Los reversed ACE1/Ang II/AT1 receptor axis upregulation in AA colon tissues and LPS-treated EGCs. These results show that Los inhibits ACE1/Ang II/AT1 receptor axis upregulation by suppressing EGC activation, resulting in reduced expression of pain mediators and inflammatory factors, thereby alleviating visceral hypersensitivity.

Development of a novel nanoprobe from alginate functionlized gold nanoparticles and 3-(dansylamino)phenylboronic acid for glucose detection and enhanced 4-nitrophenol reduction.

Gold nanoparticles (AuNPs) were prepared by a solvothermal method using sodium alginate (SA) as both, the reductant and stabilizer. The formation of SA-AuNPs was confirmed by UV-Vis spectroscopy, transmission electron microscopy, X-ray diffractometry, and X-ray photoelectron spectroscopy. SA-AuNPs were functionalized with fluorescent 3-(dansylamino)phenylboronic acid (DAPB) moieties, through interactions between boronic acids and diol groups. The fluorescence resonance energy transfer from DAPB to AuNPs quenched the fluorescence of DAPB. In the presence of glucose, the competitive binding of DAPB with glucose resulted in the release of assembled DAPB from the surface of SA-AuNPs, resulting in the increase in fluorescence intensity. Furthermore, catalytic reduction of 4-nitrophenol was monitored via spectrophotometry using DAPB functionalized SA-AuNPs probes as catalyst. Compared to SA-AuNPs, the nanoprobes exhibited higher catalytic rates.