Curcumin, Cinnamon, Green tea, Grape seed: Anti-TAU natural products

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3575183/#!po=22.2973

Curcumin, Cinnamon, Green tea, Grape seed:  Anti-TAU natural products

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The following is adapted from web link

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"Scientists have looked to dietary sources, including extracts and preparations of ethnobotanical plants, for relief of neurodegenerative disorders [47,48]; recent efforts to uncover the chemical basis of these materials have identified a number of bioactive metabolites, some with drug-development potential.

Many anti-tau natural products made by plants are polyphenols such as curcumin (4; Figure 4), a linear diarylheptanoid present at 66.8% of an optimized turmeric (Curcuma longa) extract [49]. This extract, in addition to acting as an antioxidant, was observed to significantly increase production of the anti-inflammatory cytokine IL-4 and to reduce Aβ and tau levels in Aβ-overexpressing mice [50].

Furthermore, our group has identified a potent macrocyclic diarylheptanoid from bayberry root bark (Myrica cerifera) extract, (+)-aR,11S-myricanol (5) that reduces tau levels [51]. Compound 5 reduced tau levels ex vivo in a cell culture model of tauopathy (in HeLa-C3 cells) with an EC50 value of 35 µM and is a suitable scaffold for AD drug discovery [101].

The isolation of (+)-aR,11S-myricanol (5) was accompanied by additional bayberry flavonoids, including myricetin (6) and its rhamoside glycoside myricitrin (7).

Low micromolar tau filament formation inhibition of myricetin was previously reported in vitro as well as for two other members of the flavonoid family:

the roselle (Hibiscus sabdariffa)-derived gossypetin (8) [52]

and the green tea (Camellia sinensis)-derived (−)-epicatechin-3-gallate (9) [53] showing IC50 values at 1.2, 2.0 and 1.8 µM, respectively [54].

A cinnamon (Cinnamonium zeylanicum) extract inhibiting aggregation of human tau in vitro leads to an inhibitory activity attributable to both compounds cinnamaldehyde (10) and A-type doubly linked procyanidin oligomers of the catechins/epicatechin structural classes (11) [55].

Similar procyanidins identified from grape seed (Vitis vinifera)-derived polyphenolic extracts were found to prevent tau fibrillization into neurotoxic aggregates [56].

Investigation of sage (Salvia offinalis) as a culinary source for improving cognition and memory showed that the active ingredient was the polyphenol rosmarinic acid (12), which reduced tau hyperphosphorylation in addition to attenuating several AD pathways, such as reactive oxygen species formation, lipid peroxidation, DNA fragmentation, caspase-3 activation and Aβ accumulation [57]."

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