High-purity tocotrienols (T3s) are a more potent form of vitamin E than tocopherols (TPs), and seem to act as a protective antioxidant and anti-inflammatory agent to prevent and reduce the severity of a relapse in inflammatory bowel disease (IBD).
In this experiment, a dextran sulphate sodium (DSS)-induced IBD mouse model was used and a preventive supplementation regime was set up – the animals were fed a tocotrienols-rich fraction (TRF) at either 150 mg per kilogram or 300 mg per kilogram each day to supply the colon tissue with tocotrienols before disease induction.
After administering DSS, the signs and symptoms of IBD were assessed and recorded and the progression of the disease was noted.
TRF supplementation was compared against α-tocopherol (α-TP) supplementation and mesalamine (5-ASA) treatment. There was also a healthy control group and a no-treatment control group.
Results showed that signs and symptoms of IBD, such as decrease in body weight, presence of occult blood, and state of diarrheoa, in the TRF-supplemented group were less pronounced compared to the α-TP-supplemented group. Post-mortem biopsies showed the anatomical structure of the colon epithelium was severely destroyed by DSS in the no-treatment group. The 5-ASA-treated group and the TRF-supplemented group had lesser structural destruction, while the α-TP-supplemented group had highly disorganised colonic microstructures, such as destroyed epithelium and irregular lamina propria, similar to that in the no-treatment group. T3s and α-TP were both detected at the colon tissue and the total vitamin E in the colon was twice as much in the TRF-supplemented group as in the α-TP-supplemented group. This high level of total vitamin E in colon tissue could explain the attenuation on the progression of IBD in the TRF-supplemented group.
Pro-inflammatory cytokines and enzymes were extracted from colon tissue and analysed using enzyme-linked immunosorbent assay (ELISA). Pro-inflammatory biomolecules of interest included interleukin-6 (IL-6), tumour necrosis factor- α (TNF-α), myeloperoxidase (MPO), malondialdehyde (MAD), and cyclooxygenase-2 (COX-2). Nitric oxide (NO), as a biomarker of oxidative stress, was also analysed. Results revealed that pro-inflammatory and oxidative cytokines and enzymes in the colonic tissue in the no-treatment group were greatly elevated; while 5-ASA-treatment and TRF-supplementation, in most cases, brought the concentration of these biomolecules closer to healthy levels. However, this was not seen in the α-TP-supplemented group. Nuclear factor kappa light chain enhancer of activated B cells (NF-κB), a pro-inflammatory transcription factor, was also suppressed in the TRF-supplemented group.
The results show that supplementation with TRF, not α-TP, can suppress the signs and symptoms suffered by IBD patients during relapse because the damage done to the colon tissue is restricted. This can be due to a hampered inflammatory reaction as evidenced in the near-healthy levels of pro-inflammatory biomolecules.
Dr. Lim Kee Pah earned his PhD from Nanyang Technological University, Singapore, in 2009, with a thesis on biomaterials. He then studied cardiovascular health during his post-doctoral job at National Heart Centre, Singapore. He is currently a Research Scientist at Davos Life Science Pte. Ltd. The focus of his research is on discovering health benefits that tocotrienols possess in pre-clinical and clinical studies.