Neuroprotective and Anti-Amyloid β Effect and Main Chemical Profiles of White Tea: Comparison Against Green, Oolong and Black Tea

Molecules. 2019 May 19;24(10):1926. doi: 10.3390/molecules24101926.

Abstract

White tea (WT) is one of six tea types originally derived from Fujian Province, China. White tea is known for its health-promoting properties. However, the neuroprotective and anti-aggregatory properties of WT against the hallmark toxic Alzheimer's protein, Aβ have not been investigated. In this study, WT, green tea (GT), oolong tea (OT) and black tea (BT) were manufactured using tea leaves from the cultivar Camellia sinensis (Jin Guanyin). The protective effects of these tea extracts were then studied under oxidative stress conditions via t-bhp and H2O2 exposure, in addition to Aβ treatment using a PC-12 cell model. Each tea type failed to rescue PC-12 cells from either t-bhp or H2O2-mediated toxicity, however each extract exerted significant protection against Aβ-evoked neurotoxicity. Results of the Thioflavin T Kinetic (ThT) and TEM assay showed that Aβ aggregate formation was inhibited by each tea type. Additionally, TEM also supported the different anti-aggregatory effect of WT by modifying Aβ into an amorphous and punctate aggregate morphology. Higher accumulated precedent or potential neuroprotective compounds in WT, including ECG''3Me, 8-C-ascorbyl-EGCG, GABA and Gln, in addition to flavonol or flavone glycosides detected by using UPLC-QTOF-MS and UPLC-QqQ-MS, may contribute to a favourable anti-aggregative and neuroprotective effect of WT against Aβ.

Keywords: Alzheimer’s disease; PC-12 cell; UPLC-QTOF-MS; UPLC-QqQ-MS; amyloid β; chemical profiles; oxidative stress; white tea.

Publication types

  • Comparative Study

MeSH terms

  • Amyloid beta-Peptides / drug effects*
  • Camellia sinensis / chemistry
  • Cell Line
  • Cell Survival / drug effects
  • Chromatography, High Pressure Liquid / methods
  • Humans
  • Hydrogen Peroxide / chemistry
  • Kinetics
  • Neurons / cytology
  • Neuroprotection / drug effects*
  • Neuroprotective Agents / chemistry*
  • Neuroprotective Agents / pharmacology
  • Oxidative Stress / drug effects
  • Plant Extracts / chemistry*
  • Plant Extracts / pharmacology
  • Plant Leaves / chemistry
  • Principal Component Analysis / methods
  • Tandem Mass Spectrometry / methods
  • Tea / chemistry*
  • Tea / parasitology

Substances

  • Amyloid beta-Peptides
  • Neuroprotective Agents
  • Plant Extracts
  • Tea
  • Hydrogen Peroxide