Green tea polyphenol (–)-epigallocatechin-3-gallate enhances the inhibitory effect of huperzine A on acetylcholinesterase by increasing the affinity with serum albumin

Abstract

The green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) was investigated for its enhancement effect of huperzine A on inhibiting acetylcholinesterase (AChE). The inhibitory effect of huperzine A on acetylcholinesterase is quite weak in the whole phase. EGCG hardly inhibits the AChE activity within the range 10-300 mg/kg. However, upon addition of EGCG to the huperzine A groups, a remarkably enhanced inhibitory effect was observed. The EGCG also can largely prolong the inhibitory time. These results indicate that addition of EGCG to huperzine A can reduce the dose of huperzine A required compared with huperzine A alone. The enhancement and complementary effect of EGCG on huperzine A activity may partly be due to the antioxidant property of EGCG. One of the beneficial effects of green tea is to induce a feeling of relief. It is conceivable that this function may be regulated by EGCG in the central nervous system since EGCG is distributed in the brain after oral administration. EGCG can be used as an enhanced supplement for huperzine A to treat Alzheimer's disease.

Analgesic and acetylcholinesterase inhibition potential of polyphenols from Scolopia crenata (Flacourtiaceae): An endemic medicinal plant of India

“…A large number of different kinds of natural compounds in plants with analgesic activity have been reported earlier. As suggested from a number of studies, proanthocyanidins, vitamin E, phenolic acids, flavonoids and tannins are found to promote analgesic activity (Edmonds et al, 1997;Bone and Mills, 2013;Miller et al, 2001;Zhang et al, 2009). In particular, flavonoids from medicinal plants have been reported to bind directly to the opiate receptors and inhibit neuronal transmitter receptors from activating pain neurons and exhibit analgesic activity (Havsteen, 2002).…”

“…It is to be noted that both the extracts recorded remarkable levels of non-enzymatic antioxidants which might have contributed to the AChE inhibitory activity (Table 1). Recently, several polyphenols such as phenolic acids and flavonoids, anthocyanins and vitamin E with strong antioxidant activity have been reported to play a pivotal role in preventing the pathophysiology of neurodegenerative diseases (Lloret et al, 2009;Zhang et al, 2009;Shih et al, 2010). Substrate dependent kinetic studies carried out to understand the nature of inhibition by the methanol extracts of S. crenata showed them to be non-competitive in stem bark (Fig.…”

“…Several evidences suggest that plants/plant extracts used to relieve pain have shown analgesic effects, while those used to treat cognitive disorders were found to act as AChE inhibitors (Lima et al, 2005;de Mattos et al, 2007;Stafford et al, 2008). Furthermore, polyphenols such as phenolic acids, tannins and flavonoids present in the plant materials have shown a profound analgesic and cholinesterase inhibitory properties (Bone and Mills, 2013;Zhang et al, 2009).…”

Clinical benefits of green tea consumption for cognitive dysfunction

“…Zhang et al reported that green tea catechins increased the effects of the acetylcholinesterase inhibitor, huperzine A, by increasing its affinity for serum albumin [155]. This study highlighted the possibility that green tea catechins may act to enhance the effects of other medications.…”

Medicinal Plants Anti-cholinesterase Activity and the Potential for Alzheimer’s Disease Treatment

“…HPLC analysis results in the presence of phenolic acids, flavonoids and pentacyclic triterpenoid betulinic acid in the methanol extracts of stem and leaf of S. crenata in varied amounts. Similarly, Shih, Chan [86], Zhang, Cao [87], Lloret, Badia [88] recently reported several polyphenols such as phenolic acids, flavonoids, anthocyanins and vitamin E with strong antioxidant activity that play a crucial role in the prevention of neurodegenerative diseases pathophysiology.…”