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Melatonin is more effective than taurine and 5‐hydroxytryptophan against hyperglycemia‐induced kidney‐cortex tubules injury a
Author(s) -
Derlacz Rafal A.,
Sliwinska Malgorzata,
Piekutowska Anna,
Winiarska Katarzyna,
Drozak Jakub,
Bryla Jadwiga
Publication year - 2007
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1111/j.1600-079x.2006.00405.x
Subject(s) - glutathione , melatonin , medicine , endocrinology , taurine , oxidative stress , lipid peroxidation , reactive oxygen species , chemistry , glutathione reductase , biochemistry , biology , enzyme , catalase , amino acid , glutathione peroxidase
The antioxidative effects of melatonin (Mel), 5‐hydroxytryptophan (5‐HTP) and taurine (TAU) on hyperglycemia‐induced oxidative stress was investigated in primary cultures of kidney‐cortex tubule cells grown in metabolically and hormonally defined medium. In the presence of 30 m m glucose (hyperglycemic conditions), cell viability was decreased by about 35% in comparison with that estimated in the glucose‐depleted medium probably as a result of induction of apoptosis, as concluded from: (i) chromatin condensation and DNA fragmentation assays, (ii) a significant enhancement of reactive oxygen species (ROS) production, (iii) 8‐hydroxydeoxyguanosine (8‐OHdG) generation, (iv) an increased protein peroxidation and (v) a decline of reduced glutathione (GSH) levels leading to a disturbed glutathione redox state. The addition of 100 μ m Mel to the hyperglycemic medium resulted in a twofold decrease in both 8‐OHdG accumulation and protein peroxidation as well as restoration of the control intracellular ROS levels accompanied by a substantial increase in GSH/oxidized glutathione (GSSG) ratio due to a decline in GSSG content. ROS elimination was also achieved in the presence of 1 m m TAU which diminished protein and DNA injuries by about 25% and 30%, respectively. On the contrary, the action of 100 μ m 5‐HTP on ROS level, 8‐OHdG generation, protein peroxidation and GSH/GSSG ratio was negligible. Thus, in contrast to 5‐HTP and TAU, Mel might be considered as beneficial for diabetes therapy, particularly in terms of reduction of hyperglycemia‐induced kidney injury.