Sunphenon EGCg (Epigallocatechin-Gallate) in the Early Stage of Alzheimer´s Disease

Overview

EGCG has shown a neuroprotective effect in cell-experimental and animal studies. The neuroprotective mechanism of EGCG probably bases - besides the known antioxidant effect - amongst others on the modulation of several signal transduction pathways, the influence on the expression of genes which regulate cell survival resp. programmed cell death, as well as the modulation of the mitochondrial function. In different Alzheimer models EGCG seems to cause an induction of alpha-secretase and the endothelin-converting-enzyme, as well as to prevent the aggregation of beta-amyloid to toxic oligomers through the direct binding to the unfolded peptide. The investigators therefore expect EGCG to have a positive influence on the course of the Alzheimer´s Disease.

Alzheimer's disease (AD) is a progressive dementia characterised by an ongoing loss of memory function and of at least one additional cognitive domain resulting in impairment of daily life functioning. Treatment of diseases such as diabetes mellitus, fractures and cardiovascular diseases is more expensive and complicated in patients with dementia compared to those without. The yearly costs for treatment and care of AD patients in the US are estimated to exceed 100 billion USD. Life expectancy is reported to be about 10 years after establishment of the diagnosis and is significantly reduced compared to non-demented subjects of similar age and socio-economic status. Age is the most relevant risk factor for AD, followed by genetic factors. Prevalence is less than 1% amongst individuals aged 50-60, but is reported to double every 5 years beyond the age of 60. The prevalence exceeds 30% in the age of 85-90. The only standard therapy for AD are acetylcholine-esterase inhibitors (AchEI; donepezil, galantamine, rivastigmine). AchEI exhibit a temporary stabilizing mild effect on the progression of AD. Conversion rates from "mild cognitive impairment" to AD do not seem to be beneficially influenced by AchEI. A high percentage of premature study withdrawals owing to adverse events has been observed in AchEI studies published to date. The questionable benefit may further be outweighed by high costs of the AchEI. Therefore, there is a necessity for the development of more efficacious and less expensive disease-modifying drugs with a better safety and tolerability profile. EGCG is a promising compound which has proven efficacious in AD animal models and which has shown an excellent tolerability in our 18-month clinical trial on Multiple Sclerosis currently being performed at our institution (SuniMS study, NCT00525668).