Sailuotong (SLT) modulates resting EEG activity but not pro-inflammatory cytokines in people with mild cognitive impairment

Abstract

Mild cognitive impairment (MCI) is a clinical syndrome that carries a high risk of transitioning to Alzheimer's disease (AD), the most common form of dementia. Currently, there are no approved treatments for MCI, and with the understanding that there are varying aetiologies, it is evident that a systemic multi-target approach is necessary to slow or delay progression to AD. Sailuotong (SLT) is a standardised herbal medicine formulation comprised of phytoconstituents at optimised ratios with demonstrated effects on several mechanistic pathways implicated in the pathophysiology of AD, including neuroinflammation. The aim of this thesis was to assess the neuronal correlates of chronic SLT administration using spontaneous electroencephalography (EEG) and measure the effect of the intervention on plasma pro-inflammatory cytokines. The relationship between observed relative change in electrocortical activity and pro-inflammatory cytokines were correlated with neuropsychological measures of cognition in order to explore possible underlying mechanisms of action. This sub-study analyses secondary outcome data collected during a larger randomised, double-blind, placebo-controlled clinical trial. Forty-eight participants with MCI were given 180 mg of SLT or placebo daily for 12 weeks. A total of 45 participants were included in the analyses. This study provided a first-look at the effects of SLT on neuronal function and plasma pro-inflammatory cytokines in people with MCI. SLT modulated several components across all traditional frequency bands. Relative reductions in eyes open (EO) and eyes closed (EC) alpha components were most pronounced, suggesting enhanced brain activation in the SLT group. Correlation between relative reductions in EC low alpha and IL-1B suggests that reductions in pro-inflammatory cytokines may favourably modify alpha amplitudes or vice versa. This thesis demonstrates that SLT effectively modulated spontaneous EEG and that relative reductions in alpha components may reflect beneficial effects on cognition in people with MCI.

Date of Award	2022
Original language	English