Dihydroisotanshinone I protects against menadione-induced toxicity in a primary culture of rat hepatocytes.
Dihydroisotanshinone I is a phenanthrenequinone derivative isolated from the roots of Salvia trijuga Diels. The present study demonstrated the hepatoprotective effect of dihydroisotanshinone I against menadione-induced cytotoxicity in a primary culture of rat hepatocytes. Pretreating the cells with dihydroisotanshinone I at concentrations ranging from 2.5 microM to 20 microM for 24 hours caused dose-dependent protection against hepatotoxicity induced by menadione. Intracellular glutathione level and activity of DT-diaphorase have been suggested to play important roles in menadione-induced cytotoxicity. However, treating the hepatocytes with 20 microM dihydroisotanshinone I for 24 hours did not cause a significant change in glutathione level and DT-diaphorase activity. On the contrary, adding dihydroisotanshinone I to freshly isolated hepatocytes at concentrations between 50 nM to 200 nM inhibited NADH-induced superoxide production dose-dependently as indicated by the decrease of lucigenin-amplified chemiluminescence. In addition, dihydroisotanshinone I at concentrations ranging from 5 microM to 20 microM inhibited tert-butyl hydroperoxide-induced lipid peroxidation dose-dependently in isolated hepatocytes as indicated by the level of malondialdehyde. These results suggest that the protective action of dihydroisotanshinone I against menadione-induced hepatotoxicity is attributed to its antioxidant properties including the free radical scavenging activity and inhibition of lipid peroxidation. Abbreviations. DTD:DT-diaphorase GSH:glutathione LDH:lactate dehydrogenase MDA:malondialdehyde MTT:3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide TBHP: tert-butyl hydroperoxide
Ip
Siu-Po
SP
School of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong.
Yang
Hui
H
Sun
Han-Dong
HD
Che
Chun-Tao
CT
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001205:Ascorbic Acid / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003676:Deferoxamine / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology; D005978:Glutathione / Q000187:drug effects / Q000378:metabolism; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects*; D015227:Lipid Peroxidation / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000187:drug effects / Q000378:metabolism; D010616:Phenanthrenes / Q000737:chemistry / Q000494:pharmacology*; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D027544:Salvia; D013481:Superoxides / Q000378:metabolism; D024483:Vitamin K 3 / Q000633:toxicity*
D000975:Antioxidants; D016166:Free Radical Scavengers; D010616:Phenanthrenes; D010936:Plant Extracts; D013481:Superoxides; C046825:dihydroisotanshinone I; D008315:Malondialdehyde; D024483:Vitamin K 3; D016660:NAD(P)H Dehydrogenase (Quinone); D005978:Glutathione; D003676:Deferoxamine; D001205:Ascorbic Acid