title: A pro-drug of the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) prevents differentiated SH-SY5Y cells from toxicity induced by 6-hydroxydopamine.
abstract: Regular consumption of green tea benefits people in prevention from cardiovascular disorders, obesity as well as neurodegenerative diseases. (-)-Epigallocatechin-3-gallate (EGCG) is regarded as the most biologically active catechin in green tea. However, the stability and bioavailability of EGCG are restricted. The purpose of the present study was to investigate whether a pro-drug, a fully acetylated EGCG (pEGCG), could be more effective in neuroprotection in Parkinsonism mimic cellular model. Retinoic acid (RA)-differentiated neuroblastoma SH-SY5Y cells were pre-treated with different concentrations of EGCG and pEGCG for 30 min and followed by incubation of 25 microM 6-hydroxydopamine (6-OHDA) for 24h. We found that a broad dosage range of pEGCG (from 0.1 to 10 microM) could significantly reduce lactate dehydrogenase release. Likewise, 10 microM of pEGCG was effective in reducing caspase-3 activity, while EGCG at all concentrations tested in the model failed to attenuate caspase-3 activity induced by 6-OHDA. Furthermore, Western-blot analysis showed that Akt could be one of the specific signaling pathways stimulated by pEGCG in neuroprotection. It was demonstrated that 25 microM of 6-OHDA significantly suppressed the phosphorylation level of Akt. Only pEGCG at 10 microM markedly increased its phosphorylation level compared to 6-OHDA alone. Taken together, as pEGCG has higher stability and bioavailability for further investigation, it could be a potential neuroprotective agent and our current findings may offer certain clues for optimizing its application in future.
authors.affiliation: Laboratory of Neurodegenerative Diseases, Department of Anatomy, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
authors.forename: Jianfei
authors.initials: J
authors.lastname: Chao
authors.forename: Way Kwok-Wai
authors.initials: WK
authors.lastname: Lau
authors.forename: Michelle Justine
authors.initials: MJ
authors.lastname: Huie
authors.forename: Yuen-Shan
authors.initials: YS
authors.lastname: Ho
authors.forename: Man-Shan
authors.initials: MS
authors.lastname: Yu
authors.forename: Cora Sau-Wan
authors.initials: CS
authors.lastname: Lai
authors.forename: Mingfu
authors.initials: M
authors.lastname: Wang
authors.forename: Wai-Hung
authors.initials: WH
authors.lastname: Yuen
authors.forename: Wai Har
authors.initials: WH
authors.lastname: Lam
authors.forename: Tak Hang
authors.initials: TH
authors.lastname: Chan
authors.forename: Raymond Chuen-Chung
authors.initials: RC
authors.lastname: Chang
mesh_terms: D053148:Caspase 3 / Q000378:metabolism; D002392:Catechin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D045744:Cell Line, Tumor; D002491:Central Nervous System Agents / Q000008:administration & dosage / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D016627:Oxidopamine / Q000008:administration & dosage / Q000633:toxicity*; D010300:Parkinson Disease; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D014212:Tretinoin
chemical_list: D002491:Central Nervous System Agents; D018696:Neuroprotective Agents; D014212:Tretinoin; D016627:Oxidopamine; D002392:Catechin; C045651:epigallocatechin gallate; D007770:L-Lactate Dehydrogenase; D051057:Proto-Oncogene Proteins c-akt; C505407:CASP3 protein, human; D053148:Caspase 3