Green Tea Extract Ameliorates Learning and Memory Deficits in Ischemic Rats via Its Active Component Polyphenol Epigallocatechin-3-gallate by Modulation of Oxidative Stress and Neuroinflammation

Abstract

Ischemic stroke results in brain damage and behavioral deficits including memory impairment. Protective effects of green tea extract (GTex) and its major functional polyphenol (−)-epigallocatechin gallate (EGCG) on memory were examined in cerebral ischemic rats. GTex and EGCG were administered 1 hr before middle cerebral artery ligation in rats. GTex, EGCG, and pentoxifylline (PTX) significantly improved ishemic-induced memory impairment in a Morris water maze test. Malondialdehyde (MDA) levels, glutathione (GSH), and superoxide dismutase (SOD) activity in the cerebral cortex and hippocampus were increased by long-term treatment with GTex and EGCG. Both compounds were also associated with reduced cerebral infraction breakdown of MDA and GSH in the hippocampus. In in vitro experiments, EGCG had anti-inflammatory effects in BV-2 microglia cells. EGCG inhibited lipopolysaccharide- (LPS-) induced nitric oxide production and reduced cyclooxygenase-2 and inducible nitric oxide synthase expression in BV-2 cells. GTex and its active polyphenol EGCG improved learning and memory deficits in a cerebral ischemia animal model and such protection may be due to the reduction of oxidative stress and neuroinflammation.

Green Tea Treatment Attenuates Oxidative Damage and Neuromotor Deficit Induced by an Experimental Model of Intracerebral Hemorrhage in Rats

“…This set of data shows that GT attenuates neuromotor deficit induced by hemorrhagic stroke, as previously demonstrated with ischemic stroke. It has been previously shown that GT extract and EGCG administration (the major component of green tea) attenuate neuromotor deficit, oxidative stress and lesion volume in an experimental model of focal and global ischemia (Wu et al, 2012;Chang et al, 2014;Shah et al, 2010). Chang et al (2014) had previously studied the effect of Epicatechin (EC) on a model of hemorrhagic stroke and shown that EC induces the activation of Nrf2 and protects against oxidative stress, neuromotor deficit and lesion volume in mice (Chang et al, 2014).…”

“…Green tea (Camellia sinensis) has been reckoned as a possible source of antioxidants available through diet (Wu et al, 2012;Xu et al, 2010). Catechins, a group of flavonoids, constitute around 30-45% of the solid GT extract (reviewed in (Mak, 2012)).…”

“…The beneficial effects of tea consumption are probably due to its bioactive components (catechins and their derivatives), demonstrated to act directly as radical scavengers and to exert indirect antioxidant effects through activation of transcription factors and phase II antioxidant defense, thus modulating the cellular redox state (see review: Mandel et al, (2006). The Epigallocatechin Gallate (EGCG) is a major component of GT and the administration of both GT extract and EGCG has shown to be a neuroprotective compound in experimental models of ischemic stroke, protecting the brain against oxidative stress, neuromotor deficit and lesion volume in both rats and mice (Wu et al, 2012;Chang et al, 2014;Shah et al, 2010;Schimidt et al, 2014).…”

LIM homeobox transcription factor 1B expression affects renal interstitial fibrosis and apoptosis in unilateral ureteral obstructed rats

“…Malondialdehyde (MDA), glutathione (GSH), and SOD were determined as extensively described by Wu et al (44). Kidney tissue was homogenized in 0.1 M phosphate buffer (pH 7.4) using a Ultra Turrax-T18-basic homogenizer (IKA Works, Wilmington, NC), and the homogenate was centrifuged at a 10,000 g at 4°C for 15 min to remove cellular debris.…”

Biography of biophenols: past, present and future

“…Biophenols are reported to affect various body systems, modulate immunity and fight pathogens and neoplasms [13]. Further, biophenols are proclaimed to affect mood, behaviour, memory and cognition [31][32][33][34][35]. Biophenols demonstrated-at least in vitro-abilities to modulate cell signalling pathways, react with specific receptors, interfere with cell division, modulate enzyme activities, regulate gene expression and affect epigenetics [13].…”