Article

Long-term administration of green tea catechins improves spatial cognition learning ability in rats.

Department of Environmental Physiology, Shimane University Faculty of Medicine, Izumo 693-8501, Japan.
Journal of Nutrition (Impact Factor: 4.23). 05/2006; 136(4):1043-7.
Source: PubMed

ABSTRACT Green tea catechins confer potent biological properties including antioxidation and free-radical scavenging. We investigated the effect of long-term oral administration of green tea catechins (Polyphenon E, PE: EGCG 63%; EC 11%; EGC 6%; ECG 6%) mixed with water on the spatial cognition learning ability of young rats. The learning ability of rats administered PE (0%, 0.1%, 0.5%) for 26 wk was assessed in the partially baited 8-arm radial maze. Relative to controls, those administered PE had improved reference and working memory-related learning ability. They also had lower plasma concentrations of lipid peroxides and greater plasma ferric-reducing antioxidation power than controls. Furthermore, rats administered PE had lower hippocampus reactive oxygen species concentrations than controls. We suggest that this improvement in spatial cognitive learning ability is due to the antioxidative activity of green tea catechins.

1 Follower
 · 
122 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Petiveria alliacea L. (Phytolaccaceae) is a perennial shrub native to the Amazon region and other tropical areas such as Central America and the Caribbean. Popularly known as mucuracaá, Petiveria alliacea is used in the folk medicine for a broad variety of therapeutic purpose and also in religious ceremonies by slaves as a sedative, which highlights its properties on the Central Nervous System (CNS). The present study evaluated the effects of the Petiveria alliacea leaves hydroalcoholic extract (PaLHE) on the cognition, including learning and memory. Three-month-old male and female Wistar rats (n=8-10/group) were administered with 900mg/Kg of PaLHE. The behavioral assays included Step-down Inhibitory avoidance (IA) and Morris Water Maze (MWM) tests. Consistent with our previous reports, Petiveria alliacea improved long-term memory. It also exerted previously unreported effects on short-term and spatial memory improvement, and increased learning in the tasks. The Petiveria alliacea extract elicited mnemonic effects and improved the learning process in both IA and MWM tests. Our results highlight the importance of further studies in order to identify the active substances of the PaLHE and investigate the pharmacological mechanisms that underlies the reported effects. Copyright © 2015. Published by Elsevier Ireland Ltd.
    Journal of ethnopharmacology 04/2015; 169. DOI:10.1016/j.jep.2015.04.005 · 2.94 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Diabetes mellitus (DM) is a metabolic disease that is rapidly increasing and has become a major public health problem. Type 2 DM (T2DM) is the most common type, accounting for up to 90-95% of the new diagnosed DM cases. The brain is very susceptible to glucose fluctuations and hyperglycemia-induced oxidative stress (OS). It is well known that DM and the risk of developing neurodegenerative diseases are associated. Tea, Camellia sinensis L., is one of the most consumed beverages. It contains several phytochemicals, such as polyphenols, methylxanthines (mainly caffeine) and L-theanine that are often reported to be responsible for tea’s health benefits, including in brain. Tea phytochemicals have been reported to be responsible for tea’s significant antidiabetic and neuroprotective properties and antioxidant potential. Epidemiological studies have shown that regular consumption of tea has positive effects on DM-caused complications and protects the brain against oxidative damage, contributing to an improvement of the cognitive function. Among the several reported benefits of tea consumption, those related with neurodegenerative diseases are of great interest. Herein, we discuss the potential beneficial effects of tea consumption and tea phytochemicals on DM and how their action can counteract the severe brain damage induced by this disease.
    Current Neuropharmacology 12/2014; 12(6). DOI:10.2174/1570159X13666141204220539 · 2.35 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: After water, tea from Camellia sinensis is the most consumed beverage worldwide. Tea is rich in catechin flavonoids that possess an array of bioactivity including antioxidant, anti-inflammatory, apoptotic, and probiotic mechanisms of action that may contribute to some of the putative health benefits associated with tea intake. A substantial body of evidence indicates that tea and its principal catechin, epigallocatechin gallate (EGCG) may contribute to a reduction in the risk of cardiovascular disease. Recent studies suggest EGCG may also have a positive impact on glucose tolerance and thermogenesis with implications for an effect on the pathogenesis of type 2 diabetes mellitus and obesity, respectively. This introduction to a symposium on EGCG’s role in cardiovascular disease and obesity presented at the 2006 annual meeting of the American College of Nutrition provides a background on tea and tea flavonoids and their possible relationship to health promotion and disease prevention.
    Journal of the American College of Nutrition 08/2007; 26(4):362S-365S. DOI:10.1080/07315724.2007.10719624 · 1.68 Impact Factor