The effect of epigallocatechin gallate on suppressing disease progression of ALS model mice

Lost in translation: treatment trials in the SOD1 mouse and in human ALS

Therapeutic success in the superoxide dismutase (SOD1) mouse model of amyotrophic lateral sclerosis (ALS) has not translated into effective therapy for human ALS, calling into question the utility of such preclinical data for identifying therapeutic agents that are worthy of further study in humans. This random effects meta-analysis of treatment trials in the superoxide dismutase (SOD1) mouse was undertaken in order to explore possible reasons for this failure of translational research and to identify potential pharmacological interventions that might be used in either a preventative or therapeutic trial in familial ALS. Among studies in which treatment was initiated presymptomatically, the weighted mean differences (WMDs) comparing the active treatment to control treated animals were 12 days (onset), 13 days (survival) and 5 days (survival interval). Among studies in which treatment was initiated at the time of symptom onset, the WMDs were 15 days (survival) and 8 days (survival interval). Subgroup analysis suggests that drugs such as minocycline and Cox-2 inhibitors with an anti-inflammatory mechanism of action, and anti-oxidative agents such as creatine or the manganese porphyrin AEOL-10150, appear to be the most promising for preventative and therapeutic trials respectively in patients with familial ALS. These conclusions should be tempered by the methodological limitations of the relevant literature.

Oxidative-induced retinal degeneration is attenuated by epigallocatechin gallate

The aim of this investigation was to determine whether an ingredient of green tea, epigallocatechin gallate (EGCG) could attenuate oxidative stress-induced degeneration of the retina as occurs in age-related macular degeneration (AMD) and glaucoma. Initial in vitro studies on brain membranes showed that EGCG was approximately 10 times more potent than trolox (vitamin E analogue) at attenuating lipid peroxidation caused by the nitric oxide donor, sodium nitroprusside (SNP). Subsequent immunohistochemical studies revealed that following an intraocular injection of SNP retinal photoreceptors are affected. This was supported by electroretinogram (ERG) recordings which showed both the a- and b-wave amplitudes to be significantly reduced. RT-PCR and Western blotting techniques showed that SNP caused a significant decrease in photoreceptor-specific markers (RET-P1, rhodopsin kinase), an increase in the cell death marker caspase-3, and no change in the ganglion cell specific markers, neurofilament (NF-L) and Thy-1. Importantly, when EGCG was co-injected, the detrimental effects to the retina caused by SNP were significantly blunted. The conclusion reached from this study is that EGCG is a powerful antioxidant and when injected into the eye with SNP attenuated the detrimental influence of SNP to retinal photoreceptors. Since oxidative stress has been implicated in retinal diseases like AMD and glaucoma this study provides "proof of principle" for the idea that daily intake of EGCG may help individuals suffering from retinal diseases where oxidative stress is implicated.

Neuroprotective Effects of (-)-Epigallocatechin-3-gallate in a Transgenic Mouse Model of Amyotrophic Lateral Sclerosis

The purpose of this study is to evaluate neuroprotective effects of (-)-Epigallocatechin-3-gallate (EGCG) in a transgenic mouse model of Amyotrophic lateral sclerosis (ALS). SOD1-G93A transgenic mice and wild-type mice were randomly divided into EGCG-treated groups (10 mg/kg, p.o) and vehicle-treated control groups. Rotarod measurement was performed to assess the motor function of mice starting at the age of 70 days. Nissl staining to examine the number of motor neurons and CD11b immunohistochemical staining to evaluate activation of microglia in the lumbar spinal cords were conducted at the age of 120 days. In addition, for further observation of regulation of cell signaling pathways by EGCG, we used immunohistochemical analysis for nuclear factor kappa B (NF-kappaB) and cleaved caspase-3 as well as western blot analysis to determine the expression of nitric oxide synthase (iNOS) and NF-kappaB in the spinal cord. This study demonstrated that oral administration of EGCG beginning from a pre-symptomatic stage significantly delayed the onset of disease, and extended life span. Furthermore, EGCG-treated transgenic mice showed increased number of motor neurons, diminished microglial activation, reduced immunohistochemical reaction of NF-kappaB and cleaved caspase-3 as well as reduced protein level of iNOS and NF-kappaB in the spinal cords. In conclusion, this study provides further evidences that EGCG has multifunctional therapeutic effects in the mouse model of ALS.

Dietary chelators as antioxidant enzyme mimetics: implications for dietary intervention in neurodegenerative diseases

Following recent reviews on the role of metal ions in oxidative stress and neurodegenerative diseases, this article reports advances in the study of dietary components for the control of these conditions. Poor metal ion homeostasis is credited with pathological roles in the progression of a number of disorders including Alzheimer's disease, Parkinson's disease and multiple sclerosis. Synthetic metal ion chelators continue to show promise as a new therapeutic approach for neurodegenerative disorders. Dietary chelators, unlike most vitamins, are, however, capable of negating or even reversing the roles of metal ions by: (i) decorporation of metal ions, (ii) redox silencing, (iii) dissolution of deposits, and (iv) generation of an antioxidant enzyme mimetic. This review gives a critical evaluation of recent progress in, and potential for, dietary control of neurodegeneration on the basis of the formation of antioxidant enzyme mimetics.

Role of epigallocatechin gallate (EGCG) in the treatment of breast and prostate cancer

Green tea and its major constituent epigallocatechin gallate (EGCG) have been extensively studied as a potential treatment for a variety of diseases, including cancer. Epidemiological data have suggested that EGCG may provide protective effects against hormone related cancers, namely breast or prostate cancer. Extensive in vitro investigations using both hormone responsive and non-responsive cell lines have shown that EGCG induces apoptosis and alters the expression of cell cycle regulatory proteins that are critical for cell survival and apoptosis. This review will highlight the important in vitro mechanistic actions elicited by EGCG in various breast and prostate cancer cell lines. Additionally, the actions of green tea/EGCG in in vivo models for these cancers as well as in clinical trials will be discussed.