Bibenzyl-Phenylpropane Hybrids with Immunosuppressive Activities from Dendrobium Nobile Lindl.

Fifteen bibenyls and four fluorenones, including five new bibenzyl-phenylpropane hybrids, were isolated from the aerial part of Dendrobium nobile Lindl. Their structures were determined by spectroscopic methods. Bioassay on the LPS-induced proliferations of mouse splenic B lymphocytes, and Con A-induced T lymphocytes showed that compounds 1, 2, and 14 showed excellent immunosuppressive activities with IC50 values of 1.23, 1.01, and 3.87 µM, respectively, while compounds 3-4, 7, 10, 13, and 15 exhibited moderate immunosuppressive activities with IC50 values ranging from 6.89 to 14.2 µM.

New Flavan Derivatives from the Leaves and Stems of Cassia nodosa.

Three new flavan derivatives including two methylene-linked flavan-3-ol dimers, bis(8-epiafzelechinyl)methane (1), and 8,8-(epiafzelechin-afzelechin)methane (2), a flavan-3-ol monomer, (-)-3-O-acetyl-epiafzelechin (3) and four known related compounds (4-7) were isolated from the leaves and stems of Cassia nodosa. Their structures were elucidated by extensive spectroscopic analyses and CD data. The isolates were evaluated for their antioxidant, α-glucosidase inhibitory, cytotoxic and neuroinflammatory activities, and compound 3 exhibited remarkable radical scavenging activities in both the DPPH and ABTS models with IC50 values of 2.65±1.25, and 4.78±0.91 µg/mL, respectively.

Specific antagonist of receptor for advanced glycation end­products attenuates delirium­like behaviours induced by sevoflurane anaesthesia with surgery in aged mice partially by improving damage to the blood­brain barrier.

Postoperative delirium (POD), which occurs in hospital up to 1-week post-procedure or until discharge, is a common complication, especially in older adult patients. However, the pathogenesis of POD remains unclear. Although damage to blood-brain barrier (BBB) integrity is involved in the neuropathogenesis of POD, the specific role of the BBB in POD requires further elucidation. Anaesthesia using 2% isoflurane for 4 h results in the upregulation of hippocampal receptor for advanced glycation end-products (RAGE) expression and ß-amyloid accumulation in aged rats. The present study investigated the role of RAGE in BBB integrity and its mechanisms in POD-like behaviours. The buried food, open field and Y maze tests were used to evaluate neurobehavioural changes in aged mice following 2.5% sevoflurane anaesthesia administration with exploratory laparotomy. Levels of tight junction proteins were assessed by western blotting. Multiphoton in vivo microscopy was used to observe the ultrastructural changes in the BBB in the hippocampal CA1 region. Anaesthesia with surgery decreased the levels of tight junction proteins occludin and claudin 5, increased matrix metalloproteinases (MMPs) 2 and 9, damaged the ultrastructure of the BBB and induced POD-like behaviour. FPS-ZM1, a specific RAGE antagonist, ameliorated POD-like behaviour induced by anaesthesia and surgery in aged mice. Furthermore, FPS-ZM1 also restored decreased levels of occludin and claudin 5 as well as increased levels of MMP2 and MMP9. The present findings suggested that RAGE signalling was involved in BBB damage following anaesthesia with surgery. Thus, RAGE has potential as a novel therapeutic intervention for the prevention of POD.