Please use this identifier to cite or link to this item: http://hdl.handle.net/10316/5341
Title: Tetrandrine concentrations not affecting oxidative phosphorylation protect rat liver mitochondria from oxidative stress
Authors: Fernandes, Maria A. S. 
Custódio, José B. A. 
Santos, Maria S. 
Moreno, António J. M. 
Vicente, Joaquim A. F. 
Keywords: Bisbenzylisoquinoline alkaloide; Mitochondrial bioenergetics; Permeability transition pore; Tetrandrine
Issue Date: 2006
Citation: Mitochondrion. 6:4 (2006) 176-185
Abstract: The effects of tetrandrine (6,6', 7,12-tetramethoxy-2, 2'-dimethyl-berbaman) on the mitochondrial function were assessed on oxidative stress, mitochondrial permeability transition (MPT), and bioenergetics of rat liver mitochondria. At concentrations lower than 100 nmol/mg protein, tetrandrine decreased the hydrogen peroxide formation, the extent of lipid peroxidation, the susceptibility to Ca2+-induced opening of MPT pore, and inhibited the inner membrane anion channel activity, not significantly affecting the mitochondrial bioenergetics. High tetrandrine concentrations (100-300 nmol/mg protein) stimulated succinate-dependent state 4 respiration, while some inhibition was observed for state 3 and p-trifluoromethoxyphenylhydrazone-uncoupled respirations. The respiratory control ratio and the transmembrane potential were depressed but the adenosine diphosphate to oxygen (ADP/O) ratio was less affected. A slight increase of the inner mitochondrial membrane permeability to H+ and K+ by tetrandrine was also observed. It was concluded that low concentrations of tetrandrine afford protection against liver mitochondria injury promoted by oxidative-stress events, such as hydrogen peroxide production, lipid peroxidation, and induction of MPT. Conversely, high tetrandrine concentrations revealed toxicological effects expressed by interference with mitochondrial bioenergetics, as a consequence of some inner membrane permeability to H+ and K+ and inhibition of the electron flux in the respiratory chain. The direct immediate protective role of tetrandrine against mitochondrial oxidative stress may be relevant to clarify the mechanisms responsible for its multiple pharmacological actions.
URI: http://hdl.handle.net/10316/5341
Rights: openAccess
Appears in Collections:FCTUC Ciências da Vida - Artigos em Revistas Internacionais

Files in This Item:
File Description SizeFormat
file1f961632038442239a7848b67c6a2987.pdf279.18 kBAdobe PDFView/Open
Show full item record

Page view(s)

100
checked on Nov 5, 2019

Download(s)

56
checked on Nov 5, 2019

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.