With up to half of a person's body mass consisting of skeletal muscle, chronic inflammation of those muscles – which include those found in the limbs – can result in significant physical impairment. According to University of Illinois kinesiology and community health professor Kimberly Huey, past research has demonstrated that the antioxidant properties of Vitamin E may be associated with reduced expression of certain pro-inflammatory cytokines, in vitro, in various types of cells. Cytokines are regulatory proteins that function as intercellular communicators that assist the immune system in generating a response.
To consider whether the administration of Vitamin E, in vivo, might have similar effects on skeletal and cardiac muscle, Huey and a team of Illinois researchers put Vitamin E to the test in mice. The team included study designer Rodney Johnson, a U. of I. professor of animal sciences, whose previous work has suggested a possible link, in mice, between short-term Vitamin E supplementation and reduced inflammation in the brain.
The study represents the first time researchers have looked at in vivo effects of Vitamin E administration on local inflammatory responses in skeletal and cardiac muscle.
In this study, the researchers investigated the effects of prior administration of Vitamin E in mice that were then injected with a low dose of E. coli lipopolysaccharide (LPS) to induce acute systemic inflammation. The effects were compared with those found in placebo control groups.
The research team examined the impact the Vitamin E or placebo treatment had on the mRNA and protein levels of three cytokines – interleukin (IL-6), tumor necrosis factor-alpha (TNF-alpha) and IL-1beta.
"The mice were administered Vitamin E for three days prior to giving them what amounts to a minor systemic bacterial infection," Huey said. "One thing we did – in addition to (looking at) the cytokines – was to look, in the muscle, at the amount of oxidized proteins.
"Oxidation can be detrimental, and in muscle has been associated with reduced muscle strength," Huey said.
Among the team's major findings, in terms of function, Huey said, was that "there was a significant reduction in the amount of LPS-induced oxidized proteins with Vitamin E compared to placebo."
"So that's a good thing," she said. "Potentially, if you reduce the oxidized proteins, that may correlate to increased muscle strength."
Additionally, the researchers' experiments yielded a significant decrease in two cytokines – IL-6 and IL-1beta – with Vitamin E, compared with the placebo.
That finding translates to somewhat mixed reviews.