Researchers from the Universiti Putra Malaysia found that palm tocotrienol, a more concentrated form of vitamin E, reduced the activity of the microglial co-stimulator molecule CD40, which is associated with the development of neurodegenerative diseases.
“Our data aids the further characterisation of the actions of tocotrienols on microglia, offering insight into the potential modulatory properties of palm tocotrienols on microglial inflammatory responses within the central nervous system (CNS)” they wrote in the Malaysian Journal of Medicine and Health Sciences.
Microglia cells play a key role overall brain maintenance by continuously scavenging the central nervous system for plaques, damaged or unnecessary neurons and synapses, and infectious agents.
To conduct the in vitro study, microglia (BV2) cultured cells were treated with two different concentrations of tocotrienols variants supplied by ExcelVite, a manufacturer of the palm oil-based vitamin E in Malaysia.
The first was δ-tocotrienol in 3.96 μg/mL and 19.80 μg/mL concentrations.
The second was Tocomin 50%, (tocotrienol-tocopherol complex) in 47.50 μg/mL and 237.50 μg/mL concentrations.
Twenty-four hours after the tocotrienol doses, the BV2 cultures were then stimulated with 1 mL of lipopolysaccharide (LPS) to induce CD40 activity.
Findings revealed that both δ- tocotrienol and Tocomin 50% can reduce the number of CD40+LPS-stimulated BV2 microglia.
Researchers noted that δ-tocotrienol at 19.80 μg/mL concentration reduced 85.7% of CD40 cells, while Tocomin50% at 237.50 μg/mL decreased 53.9% of CD40 cells in the BV2 cultures.
CD40 expression levels
The effects of tocotrienols on the intensity of CD40 expression levels by BV2 cells were also determined.
“Not only do the number of CD40+ BV2 cells reduce following δ- tocotrienol and Tocomin 50% treatment (at both doses), but the levels of their CD40 expression per cell is also limited,” the study revealed.
“The 237.5 μg/mL of Tocomin 50% limited CD40 expression of BV2 cells by 49.1% significantly. These results reveal that tocotrienols are not only capable of limiting the number of BV2 microglia cells from acquiring CD40 expression but can also limit the degree of CD40 expression per cell.”
The study also tested for nitric oxide (NO), produced by microglia cells during inflammation. Presence of NO can be harmful to neurones and attributed to detrimental effects of various neurodegenerative diseases, including neuronal death in Alzheimer’s and Parkinson’s diseases.
While a previous study revealed that tocotrienol could inhibit NO, this current study showed it does not reduce NO levels by scavenging.
Therefore, “Further work is underway to assess the effects of palm tocotrienols upon the key enzyme in this paradigm, the inducible nitric oxide synthase (iNOS) as will assist us to understand its underlying mechanism of action on NO production by microglia.”
Based on these results, the researchers concluded that palm tocotrienol can help modulate CD40 activity in microglia cells.
“Our results provide novel insight into the role of palm tocotrienols in modulating microglia responses,” they said.
“This may offer a potential therapeutic focus for neurodegenerative and neuro-inflammatory diseases by palm tocotrienols.”
Source: Malaysian Journal of Medicine and Health Sciences
Vol 12 (2) June 2017, Page 1
“Palm tocotrienols reduce lipopolysaccharide-stimulated inflammatory responses of microglia”
Authors: Shi Wei Tan, Maha Abdullah et al.