A new study reveals that palm tocotrienol may attenuate vascular function impairment in rats fed a high-fat western diet
In this interesting study, male Wistar-Hooded rats were randomly assigned into standard diet (normal fat content) and western diet (high fat content) for 12 weeks: 40mg/kg/day of EVNol (formerly known as Tocomin, supplied by ExcelVite) or peanut oil were administered subcutaneously from week 8 until cessation of the study.
In addition to weekly measurement of food intake and body weight, production of nitric oxide (NO) and superoxide, and associated protein expressions were measured too.
The objective of this study was to examine whether tocotrienol has acute protective actions in oxidative stress-induced endothelial dysfunction.
A good vascular function is highly dependent on endothelial relaxation. When endothelium-dependent relaxation is impaired, the production of NADPH and superoxide increases, followed by vascular oxidative stress.
Oxidative stress leads to increased protein expression such as caveolin-1, decreased protein expression of eNOS (endothelial NO synthase), calmodulin, phosphorylated Akt, as well as reduced NO-mediated and Acetylcholine (Ach)-induced endothelium relaxation, which collectively leads to vascular impairment.
Rats fed a western diet showed significantly higher body weights and epididymal fat mass compared with rats fed a standard diet. Interestingly, after undergoing 4 weeks of EVNol supplementation, rats fed a western diet demonstrated significantly increased Ach-induced relaxation and NO-mediated relaxation as well as decreased production of superoxide, expression of Nox2 and caveolin-1 when compared with rats fed a standard diet.
By contrast, the expression of eNOS, calmodulin and phosphorylated Akt in rats fed a western diet were similar to rats fed a standard diet. Taken together, these events indicate that EVNol supplementation promotes significantly better vascular functions by promoting NO-mediated endothelium relaxation via increased or decreased protein expression.
“Back in 2008, Rasool and team demonstrated that 2 months of supplementation with 50, 100 and 200mg of EVNol SupraBio (bioenhanced palm tocotrienol/ tocopherol complex) among healthy human subjects promoted arterial compliance by reducing both pulse wave velocity and augmentation index values. And now once again, this particular study conducted at the RMIT University in Australia shows that EVNol (natural full spectrum palm tocotrienol/tocopherol complex) has acute protective effects of endothelial functions in the presence of oxidative stress."
"Although the study was done out with rats, it can be postulated that a daily dose of 155mg of EVNol (human equivalent dose for a 60-kg adult) could potentially mitigate obesity induced oxidative stress-associated vascular endothelial impairment. Hence, EVNol and EVNol SupraBio may be beneficial for supporting heart health by promoting endothelium relaxation and arterial compliance,” says CheeYen Lau, Nutritionist of ExcelVite.