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Cholestane-3β,5α,6β-triol (3β,5α,6β-triol) is formed from cholestan-5,6-epoxide (5,6-EC) in a reaction catalysed by cholesterol epoxide hydrolase, following formation of 5,6-EC through free radical oxidation of cholesterol. 7-Oxocholesterol (7-OC) and 7β-hydroxycholesterol (7β-HC) can also be formed by free radical oxidation of cholesterol. Here we investigate how 3β,5α,6β-triol, 7-OC and 7β-HC are metabolised to bile acids. We show, by monitoring oxysterol metabolites in plasma samples rich in 3β,5α,6β-triol, 7-OC and 7β-HC, that these three oxysterols fall into novel branches of the acidic pathway of bile acid biosynthesis becoming (25R)26-hydroxylated then carboxylated, 24-hydroxylated and side-chain shortened to give the final products 3β,5α,6β-trihydroxycholanoic, 3β-hydroxy-7-oxochol-5-enoic and 3β,7β-dihydroxychol-5-enoic acids, respectively. The intermediates in these pathways may be causative of some phenotypical features of, and/or have diagnostic value for, the lysosomal storage diseases, Niemann Pick types C and B and lysosomal acid lipase deficiency. Free radical derived oxysterols are metabolised in human to unusual bile acids via novel branches of the acidic pathway, intermediates in these pathways are observed in plasma.
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http://dx.doi.org/10.1016/j.freeradbiomed.2019.04.020 | DOI Listing |
Neurol Res
September 2025
Toxicology Research Center, AJA University of Medical Sciences, Tehran, Iran.
Background: Free radicals play a key role in spinal cord injury and curcumin has the potential to act as an antioxidant agent. Controlled delivery of curcumin can be achieved through encapsulation in bovine serum albumin to form nanoparticles, and acellular scaffold can bridge lesions and improve axonal growth in spinal cord injury.
Objective: In this study, we evaluated the antioxidant effects of the scaffold containing curcumin nanoparticles in the unilateral spinal cord injury model in male rats.
Zhong Nan Da Xue Xue Bao Yi Xue Ban
May 2025
Department of Pathology, First Clinical College, Changzhi Medical College, Changzhi 046000.
Objectives: Acute lung injury (ALI) is an acute respiratory failure syndrome characterized by impaired gas exchange. Due to the lack of effective targeted drugs, it is associated with high mortality and poor prognosis. (TW) has demonstrated anti-inflammatory activity in the treatment of various diseases.
View Article and Find Full Text PDFChem Soc Rev
September 2025
Department of Chemistry and Biochemistry, UCSD-CNRS Joint Research Laboratory (IRL3555), University of California, San Diego, La Jolla, CA 92093-0358, USA.
N-Heterocyclic carbenes (NHCs) hold a unique significance in organometallic catalysis and are powerful organocatalysts for a variety of organic transformations involving crucial intermediates such as Breslow intermediates (BIs), deprotonated BIs (BI-s), ketyl radicals (KRs), and acyl azoliums (AAs). To address the remaining challenges facing reactions catalyzed by NHCs, non-classical stable carbenes, namely 1,2,3-triazolylidenes (MICs), cousins of NHCs, have shown great potential. MICs share similar features with typical NHCs but possess unique characteristics, such as enhanced σ-donor ability and absence of dimerization.
View Article and Find Full Text PDFHistol Histopathol
September 2025
Institute of Pathology, University Hospital Bonn, Bonn, Germany.
Aims: We aimed to analyze CD63, a cell surface protein that has been associated with tumor aggressiveness in several cancers, including breast, colorectal, and lung cancer, as well as melanoma, in prostate cancer.
Methods: CD63 expression was analyzed immunohistochemically in a cohort of primary prostate cancers from 281 patients. The results were correlated with clinico-pathologic parameters, including biochemical recurrence.
Toxicol Mech Methods
September 2025
Lung Diseases Research Center, Ardabil University of Medical Sciences, Ardabil, Iran.
Mechanistic studies have been suggested that toxic effects of bleomycin are generally attributed to formation of free radicals, mitochondria damages, oxidative stress and inflammation. For this purpose, we explored the direct exposure of bleomycin and protective effects of the betanin and vanillic acid separately against its possible toxicity in rat lung isolated mitochondria. Various mitochondrial toxicity parameters were evaluated including; succinate dehydrogenases (SDH) activity, reactive oxygen species (ROS) formation, mitochondrial swelling, mitochondrial membrane potential (MMP) collapse, malondialdehyde (MDA) and glutathione disulfide (GSSG) levels.
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