Antioxidant properties of silybin glycosides.
New soluble derivatives of the hepatoprotective flavonolignan silybin (1), namely silybin galactoside (2), glucoside (3), lactoside (4) and maltoside (5) were investigated for their radical scavenging and antilipoperoxidation properties. According to cyclic voltammetry the results show that glycosides are weaker electron donors than silybin, although it was of interest that they were found to be more potent scavengers of the 1,1-diphenyl-2-picrylhydrazyl and the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)-derived radicals. The glycosides (2)-(5) were more efficient than silybin in preventing tert-butylhydroperoxide-induced lipoperoxidation of rat liver mitochondrial membranes. Furthermore, glycosides (2)-(5) were significantly more cytoprotective than silybin in tert-butylhydroperoxide-damaged rat erythrocytes and primary hepatocyte cultures. Glycosylation of silybin substantially reduced its toxic effects in primary cultured hepatocytes observed during prolonged incubation. These results suggest that silybin glycosides are suitable soluble derivatives of silybin for experimental studies and may have therapeutic potential.
Kosina
Pavel
P
Centre for Bioanalytical Research, Palacký University, Hnĕvotínská 3, 775 15 Olomouc, Czech Republic.
Kren
Vladimír
V
Gebhardt
Rolf
R
Grambal
Frantisek
F
Ulrichová
Jitka
J
Walterová
Daniela
D
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002478:Cells, Cultured / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000187:drug effects; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006027:Glycosides / Q000737:chemistry / Q000494:pharmacology*; D022781:Hepatocytes / Q000187:drug effects; D015227:Lipid Peroxidation / Q000187:drug effects*; D008099:Liver / Q000166:cytology / Q000187:drug effects; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects; D008517:Phytotherapy; D051381:Rats; D017208:Rats, Wistar; D012838:Silymarin / Q000737:chemistry / Q000494:pharmacology*
D000975:Antioxidants; D016166:Free Radical Scavengers; D006027:Glycosides; D012838:Silymarin