Neuroprotective Effects and Mechanisms of Tea Bioactive Components in Neurodegenerative Diseases.

As the population ages, neurodegenerative diseases such as Parkinson's disease (PD) and Alzheimer's disease (AD) impose a heavy burden on society and families. The pathogeneses of PD and AD are complex. There are no radical cures for the diseases, and existing therapeutic agents for PD and AD have diverse side effects. Tea contains many bioactive components such as polyphenols, theanine, caffeine, and theaflavins. Some investigations of epidemiology have demonstrated that drinking tea can decrease the risk of PD and AD. Tea polyphenols can lower the morbidity of PD and AD by reducing oxidative stress and regulating signaling pathways and metal chelation. Theanine can inhibit the glutamate receptors and regulate the extracellular concentration of glutamine, presenting neuroprotective effects. Additionally, the neuroprotective mechanisms of caffeine and theaflavins may contribute to the ability to antagonize the adenosine receptor A2AR and the antioxidant properties, respectively. Thus, tea bioactive components might be useful for neuronal degeneration treatment in the future. In the present paper, the neuro protection and the mechanisms of tea and its bioactive components are reviewed. Moreover, the potential challenges and future work are also discussed.

Utilization of albumin fraction from defatted rice bran to stabilize and deliver (-)-epigallocatechin gallate.

This work aims to use defatted rice bran albumin (RBA) for delivering epigallocatechin gallate (EGCg). The mode of RBA particle size shifted from 142 nm to 164 nm upon interaction with EGCg. Hydrophobic interaction is the major force between EGCg and RBA resulted in the formation of EGCg-RBA complex based on fluorescence quenching. Upon incorporation into RBA, the recovery of EGCg in pH 7.4 phosphate buffer was elevated by 2 folds. The recovery of EGCg in EGCg-RBA was 18.9% after 2 h intestinal digestion, being higher than 7.6% of native EGCg. The pretreatments of HT-29 cells with EGCg, RBA and EGCg-RBA significantly repressed the transcriptional activation of mitogen-activated protein kinase 14, nuclear transcription factor-κB, and activators of transcription 3 as stimulated with interleukin-1ß afterwards, leading to attenuated expressions of corresponding downstream genes. Antioxidant ability importantly functioned in anti-inflammation. RBA is a promising vehicle with inherent anti-inflammatory property for stabilizing and delivering EGCg.

Theacrine From Camellia kucha and Its Health Beneficial Effects.

Theacrine, i.e., 1,3,7,9-tetramethyluric acid, is one of the major purine alkaloids found in leaf of a wild tea plant species Camellia kucha Hung T. Chang. Theacrine has been attracted great attentions academically owing to its diverse health benefits. Present review examines the advances in the research on the health beneficial effects of theacrine, including antioxidant effect, anti-inflammatory effect, locomotor activation and reducing fatigue effects, improving cognitive effect, hypnotic effect, ameliorating lipid metabolism and inhibiting breast cancer cell metastasis effect. The inconsistent results in this research field and further expectations were also discussed.