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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Antioxidants, Apoptosis, Autophagy, Blotting, Western, Caspases, Cell Cycle, Cell Proliferation, Cells, Cultured, Colitis, Ulcerative, Extracellular Matrix, Fibroblast Growth Factor 2, Fibroblasts, Fluorescent Antibody Technique, Humans, Intestines, Mitochondria, Mitochondrial Membrane Transport Proteins, Poly(ADP-ribose) Polymerases, Tocotrienols.
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Do tocotrienols have potent antifibrogenic effects in human intestinal fibroblasts? Context: Excessive fibroblast expansion and extracellular matrix (ECM) deposition are key events for the development of bowel stenosis in Crohn's disease (CD) patients. Tocotrienols are vitamin E compounds with proven in vitro antifibrogenic effects on rat pancreatic fibroblasts. We aimed at investigating the effects of tocotrienols on human intestinal fibroblast (HIF) proliferation, apoptosis, autophagy, and synthesis of ECM. HIF isolated from CD, ulcerative colitis (UC), and normal intestine were treated with tocotrienol-rich fraction (TRF) from palm oil. HIF proliferation was quantified by (3) H-thymidine incorporation, apoptosis was studied by DNA fragmentation, propidium iodide staining, caspase activation, and poly(ADP-ribose) polymerase cleavage, autophagy was analyzed by quantification of LC3 protein and identification of autophagic vesicles by immunofluorescence and production of ECM components was measured by Western blot. TRF significantly reduced HIF proliferation and prevented basic fibroblast growth factor-induced proliferation in CD and UC, but not control HIF. TRF enhanced HIF death by promoting apoptosis and autophagy. HIF apoptosis, but not autophagy, was prevented by the pan-caspase inhibitor zVAD-fmk, whereas both types of cell death were prevented when the mitochondrial permeability transition pore was blocked by cyclosporin A, demonstrating a key role of the mitochondria in these processes. TRF diminished procollagen type I and laminin γ-1 production by HIF.
assistant
Tocotrienols exert multiple effects on HIF, reducing cell proliferation, enhancing programmed cell death through apoptosis and autophagy, and decreasing ECM production. Considering their in vitro antifibrogenic properties, tocotrienols could be useful to treat or prevent bowel fibrosis in CD patients. Final Decision: yes