Nov 22(ABC): Alzheimer’s disease (AD), the most common type of dementia, leads to cognitive decline and memory loss. Experts have yet to understand exactly how this crippling neurological disorder develops and progresses.
The impact of AD on the brain includes plaque accumulation, increase in brain immune cells, neuroinflammation, and impaired neuronal signaling.
Mounting evidence suggests that reactivation of the herpes simplex virus (HSV-1) may be responsible for the onset of these features.
Tufts University researchers recently built 2D and 3D human brain tissue models of herpes-induced AD to test the neuroprotective potential of pharmaceutical and plant-based compounds.
Research associate Dr. Dana Cairns, who led this investigation, said that these findings “provided some of the first evidence for direct causality of HSV-1 in AD in human brain tissues.”
In her team’s analysis, green tea compounds called catechins (GTC), and resveratrol, stood out for their “strong anti-plaque properties, functional neuroprotective benefits, and minimal neurotoxicity.”
The study appears in the journal Free Radical Biology and Medicine.
Herpes and Alzheimer’s disease
The Centers for Disease Control and PreventionTrusted Source (CDC) estimates that 47.8% of Americans ages 14–49 years carry the herpes simplex virus (HSV-1). This common pathogen can lie latent within the brain’s neurons for decades.
Tuft’s previous study with the University of Oxford demonstrated that the varicella-zoster virus (VZV), which causes chickenpox and shingles, may activate HSV-1 and incite inflammation in the brain.
This inflammation may lead to a cascade of well-known AD markers, including amyloid beta and tau protein tangles and neuronal dysfunction.
Choosing neuroprotective compounds
The Tufts team believed that their model’s “rapid and robust” simulation of AD symptoms could provide a platform for vetting neuroprotective compounds.
They screened 21 compounds, including non-AD medications approved by the FDA, dietary and herbal supplements, and nutraceuticals reputed as anti-inflammatory, “anti-aging,” or pro-cognition. These included caffeine, camphor, citicoline, GTC, insulin, metformin, resveratrol, and zolmitriptan.
Green tea’s pro-cognitive effect
Green tea consumption has demonstrated the potential to reduce cognitive dysfunction in observational studies.
Green tea leaves’ GTCs might target amyloid misfolding that is a common mechanism in AD, according to a 2021 Biomolecules study.
Physician and author Dr. Michael Greger, who was not involved in this study, discussed green tea’s antiviral properties in an April 2021 podcast:
“Unlike antiviral drugs, green tea appears to help by boosting the immune system, enhancing the proliferation and activity of gamma delta T cells, a type of immune cell that acts as ‘a first-line defense against infection.’”
The doctor also purported that GTC may help reduce oxidative damage, fight