title: Epigallocatechin gallate inhibits the HIV reverse transcription step.
abstract: BACKGROUND
  Epigallocatechin gallate (EGCG), the most abundant catechin in green tea, has been reported to inhibit HIV-1 replication prior to its integration into host DNA via various proposed mechanisms; however, the specific main target(s) of EGCG remain unclear. In this study, we investigated a number of these proposed detailed mechanism(s) using a cell-based model.
  
  
  METHODS
  Multinuclear activation of galactosidase indicator assays were used for all experiments, including examination of the time of addition and the synergisms with a nucleoside reverse transcriptase inhibitor, 3'-azido-3'-deoxythymidine (AZT).
  
  
  RESULTS
  The experiments revealed that EGCG suppressed both HIV-1(IIIB) and HIV-2(EHO) infection in HeLa-CD4-LTR-β-gal cells, with relatively low 50% effective concentrations of 1.6 and 2.0 μM, respectively. The inhibitory profile of EGCG generated using a time-of-addition assay was identical to that of a non-nucleoside reverse transcriptase inhibitor (NNRTI), MKC-442. Furthermore, synergistic inhibition was observed in EGCG with AZT.
  
  
  CONCLUSIONS
  Based on our findings, EGCG appears to act mainly as an allosteric reverse transcriptase inhibitor with mechanisms different from those of currently approved NNRTIs that directly interact with the NNRTI binding pocket. Thus, EGCG is a good candidate for use as an additional or supportive anti-HIV agent derived from natural plants.
authors: Division of Emerging Infectious Diseases, Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
authors: Shenwei
authors: S
authors: Li
authors: Toshio
authors: T
authors: Hattori
authors: Eiichi N
authors: EN
authors: Kodama
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical; D004357:Drug Synergism; D015658:HIV Infections / Q000188:drug therapy / Q000821:virology; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors; D015497:HIV-1 / Q000187:drug effects; D015498:HIV-2 / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology*; D048348:Reverse Transcription / Q000187:drug effects; D014498:Uracil / Q000031:analogs & derivatives / Q000494:pharmacology; D015215:Zidovudine / Q000494:pharmacology
chemical_list: D019380:Anti-HIV Agents; D018894:Reverse Transcriptase Inhibitors; D015215:Zidovudine; D014498:Uracil; D002392:Catechin; C045651:epigallocatechin gallate; D054303:HIV Reverse Transcriptase; C057580:gallocatechol; C083858:emivirine