Reduced infiltration of regulatory T cells in tumours from mice fed daily with gamma-tocotrienol supplementation

Single-centre, randomised clinical trial of the immunomodulatory mechanisms of daily supplementation of palm tocotrienol-rich fraction in healthy human volunteers following influenza vaccination

Background

Vitamin E from palm oil, known as the tocotrienol-rich fraction (TRF), has been shown to have immune-enhancing activity. To date, only one dose of TRF (400 mg daily) has been tested in a clinical trial. The proposed study will evaluate the immune-enhancing activity effects of lower doses (200, 100 and 50 mg) in a clinical trial using an influenza vaccine as the immunological challenge.

Methods

A single-centre, randomised, parallel, double-blinded, placebo-controlled clinical trial with balance allocation involving five arms will be conducted. The healthy volunteers recruited will be randomly assigned to one of the arms, and they will be asked to take the respective supplements (400 mg, 200 mg, 100 mg, 50 mg of TRF or placebo) daily with their dinner. The volunteers will receive the influenza vaccine after four weeks. They will be asked to return to the study site four weeks later. A blood sample will be taken for the study at baseline, four and eight weeks. Primary outcome measures will be antibody levels to influenza, blood leucocyte profile and cytokine production. Secondary outcomes will be correlating plasma vitamin E levels with immune responses, plasma proteins and gene expression patterns. The findings from this study will be published in relevant peer-reviewed journals and presented at relevant national and international scientific meetings.

Conclusions

The recent world events have created the awareness of having a healthy and functional immune system. Nutrition plays an important role in helping the immune system to function optimally. This study will show the effects of lower doses of TRF in boosting the immune response of healthy individuals and also elucidate the mechanisms through which TRF exerts its immune-enhancing effects.

Clinical trial registration

Australian New Zealand Clinical Trials Registry (ANZCTR) [ ACTRN12622000844741] dated 15 June 2022.

Protocol version

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The Effects of Tocotrienol on Gut Microbiota: A Scoping Review

Gut dysbiosis has been associated with many chronic diseases, such as obesity, inflammatory bowel disease, and cancer. Gut dysbiosis triggers these diseases through the activation of the immune system by the endotoxins produced by gut microbiota, which leads to systemic inflammation. In addition to pre-/pro-/postbiotics, many natural products can restore healthy gut microbiota composition. Tocotrienol, which is a subfamily of vitamin E, has been demonstrated to have such effects. This scoping review presents an overview of the effects of tocotrienol on gut microbiota according to the existing scientific literature. A literature search to identify relevant studies was conducted using PubMed, Scopus, and Web of Science. Only original research articles which aligned with the review's objective were examined. Six relevant studies investigating the effects of tocotrienol on gut microbiota were included. All of the studies used animal models to demonstrate that tocotrienol altered the gut microbiota composition, but none demonstrated the mechanism by which this occurred. The studies induced diseases known to be associated with gut dysbiosis in rats. Tocotrienol partially restored the gut microbiota compositions of the diseased rats so that they resembled those of the healthy rats. Tocotrienol also demonstrated strong anti-inflammatory effects in these animals. In conclusion, tocotrienol could exert anti-inflammatory effects by suppressing inflammation directly or partially by altering the gut microbiota composition, thus achieving its therapeutic effects.

Higher Intake of Fat, Vitamin E-(β+γ), Magnesium, Sodium, and Copper Increases the Susceptibility to Prostatitis-like Symptoms: Evidence from a Chinese Adult Cohort

Background: Prostatitis-like symptoms (PLS) lead to severe discomfort in males in their daily lives. Diet has been established as affecting PLS in our prior study, but the effect of nutrients, particularly for micronutrients remains largely unclear. Methods: This study enrolled 1284 participants from August 2020 to March 2021. The National Institute of Health−Chronic Prostatitis Symptom Index was used to assess PLS. The diet composition was evaluated by the Chinese Food Composition Tables. Results: Participants were separated into PLS (n = 216), control (n = 432), and noninflammatory-abnormal symptoms (NIANS) (n = 608) groups. We observed higher levels of carotene, vitamin C, vitamin E-(β+γ) and subclass, zinc, magnesium, selenium, potassium, sodium, iron and manganese in the PLS group than in the control group. After adjustment for the potential confounders, the elevated risk from IQR2 to IQR4 of fat (P for trend = 0.011), vitamin E-(β+γ) (P for trend = 0.003), magnesium (P for trend = 0.004), sodium (P for trend = 0.001) and copper (P for trend < 0.001) was identified. Conclusions: This is the first study to evaluate the nutrient distribution in PLS patients and reveal that the higher intake of fat, vitamin E-(β+γ), magnesium, sodium, and copper is associated with a risk of PLS.

Fat-Soluble Vitamin Deficiencies and Disruption of the Immune System in Pancreatic Cancer: A Vicious Cycle

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) is currently an increasing contributor to cancer-related mortality. Despite advances in cancer treatment, PDAC survival rates have remained roughly unchanged over the years. Specifically, late diagnosis and insensitivity to currently available therapeutic regimens have been identified as the main causes for its poor survival. Pancreatic exocrine insufficiency (PEI) is a typical complication associated with PDAC diagnosis and pancreatic surgery. Pancreatic exocrine insufficiency, a major contributor to maldigestion in PDAC, is often not treated because it remains undetected because of lack of overt signs and symptoms. In this review, we will focus on the major consequences of PEI, including the inadequacy of lipase excretion, which results in deficiency of fat-soluble vitamins. Because PDAC is known for its immune-high jacking mechanisms, we describe key features in which deficiencies of fat-soluble vitamins may contribute to the aggressive biological behavior and immune evasion in PDAC. Because PEI has been shown to worsen survival rates in patients with PDAC, detecting PEI and the related fat-soluble vitamin deficits at the time of PDAC diagnosis is critical. Moreover, timely supplementation of pancreatic enzymes and fat-soluble vitamins may improve outcomes for PDAC patients.

Gamma-tocotrienol modifies methylation of HOXA10, IRF4 and RORα genes in CD4+ T-lymphocytes: Evidence from a syngeneic mouse model of breast cancer

DNA methylation plays a crucial role in polarising naïve lymphocytes towards their various sub-populations to fight against many immune challenges including establishment of tumour. Gamma-tocotrienol (γT3) is a natural form of vitamin E, reported to possess anticancer and immunomodulatory effects. This study reports the anticancer effects of γT3 through modulation of DNA methylation in several genes in CD4⁺ T-lymphocytes using a syngeneic mouse model of breast cancer. Female BALB/c mice were fed with γT3 or vehicle (soy oil) for two-weeks via oral gavage before they were inoculated with 4T1 mouse mammary cancer cells. Supplementation continued until the mice were sacrificed. At autopsy, blood was collected via cardiac puncture and CD4⁺ T-cells were isolated for DNA extraction. The DNA was analysed using the EpiTech Methyl II mouse T-helper cell differentiation PCR array. γT3 supplementation reduced tumour growth in the tumour-induced animals and modulated host immune system by inducing changes in DNA methylation patterns of the HOXA10, IRF4 and RORα genes, which are involved in differentiation and clonal expansion of CD4⁺ T-cells. Results suggest that γT3 may enhance cell-mediated immune response in mice with breast cancer by inducing changes in DNA methylation pattern.

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γT3 supplementation reduced tumour growth in a syngeneic mouse model of breast cancer.

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Dietary γT3 decreased DNA methylation in Hoxa10 gene in the CD4⁺ T-cells from tumour-laden mice.

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Dietary γT3 increased DNA methylation in Irf4 and RORα genes in the CD4⁺ T-cells from tumour-laden mice.