When treated with protopine and alkalized extracts of the tuber of Corydalis ternata for one year, significant decrease in glutamate level and increase in glutamate dehydrogenase (GDH) activity was observed in rat brains. The expression of GDH between the two groups remained unchanged as determined by Western and Northern blot analysis, suggesting a post-translational regulation of GDH activity in alkalized extracts treated rat brains. The stimulatory effects of alkalized extracts and protopine on the GDH activity was further examined in vitro with two types of human GDH isozymes, hGDH1 (house-keeping GDH) and hGDH2 (nerve-specific GDH). Alkalized extracts and protopine activated the human GDH isozymes up to 4.8-fold. hGDH2 (nervespecific GDH) was more sensitively affected by 1 mM ADP than hGDH1 (house-keeping GDH) on the activation by alkalized extracts. Studies with cassette mutagenesis at ADP-binding site showed that hGDH2 was more sensitively regulated by ADP than hGDH1 on the activation by Corydalis ternata. Our results suggest that prolonged exposure to Corydalis ternata may be one of the ways to regulate glutamate concentration in brain through the activation of GDH.
Animals ; Berberine Alkaloids/pharmacology ; Brain/*drug effects/enzymology ; Corydalis/*chemistry ; Enzyme Activation/drug effects ; Glutamate Dehydrogenase/genetics/*metabolism ; Glutamic Acid/*metabolism ; Isoenzymes/genetics/metabolism ; Plant Extracts/pharmacology ; RNA, Messenger/analysis/metabolism ; Rats ; Research Support, Non-U.S. Gov't

This study is to investigate the protection effect of schisandrin B (Sch B) against oxidation stress of HK-2 cells induced by cisplatin and the mechanisms involved. HK-2 cells were cultured and divided into different groups: solvent control group, cisplatin exposure group, positive group, Sch B treatment group. Cell viability and toxicity were evaluated by MTT and LDH assay. GSH level and SOD enzymes activities were also measured. DCFH-DA as fluorescence probe was used to detect ROS level by fluorescence microplate reader. Nrf2 translocation was detected by Western blotting. Real time Q-PCR was used to detect expressions of NQO1, HO-1 and GCLC mRNA level. The results showed that Sch B could significantly inhibit the decline of cell viability induced by cisplatin treatment (P < 0.05) and the protective effect was in a dose dependent manner. Furthermore, Sch B treatment significantly inhibited the increase of ROS level induced by cisplatin and reversed the decrease of GSH level (P < 0.05). When Sch B concentration was up to 5 micromol x L(-1), SOD enzyme activities were also enhanced significantly compared with that of the cisplatin group (P < 0.05). It was shown that Sch B could cause nuclear accumulation of Nrf2 in association with downstream activation of Nrf2 mediated oxidative response genes such as GCLC, NQO1 and HO-1. These results suggested Sch B could protect against the oxidative damage of HK-2 cells induced by cisplatin via the activation of Nrf2/ARE signal pathway.
Antineoplastic Agents ; toxicity ; Antioxidants ; isolation & purification ; pharmacology ; Cell Line ; Cell Survival ; drug effects ; Cisplatin ; toxicity ; Cyclooctanes ; isolation & purification ; pharmacology ; Glutamate-Cysteine Ligase ; genetics ; metabolism ; Glutathione ; metabolism ; Heme Oxygenase-1 ; genetics ; metabolism ; Humans ; Kidney Tubules, Proximal ; cytology ; metabolism ; L-Lactate Dehydrogenase ; metabolism ; Lignans ; isolation & purification ; pharmacology ; NAD(P)H Dehydrogenase (Quinone) ; genetics ; metabolism ; NF-E2-Related Factor 2 ; genetics ; metabolism ; Polycyclic Compounds ; isolation & purification ; pharmacology ; RNA, Messenger ; metabolism ; Reactive Oxygen Species ; metabolism ; Schisandra ; chemistry ; Signal Transduction ; Superoxide Dismutase ; metabolism

11-beta-Hydroxysteroid Dehydrogenase Type 1 ; genetics ; metabolism ; Adipose Tissue, White ; drug effects ; Animals ; Animals, Newborn ; Blood Glucose ; metabolism ; Body Weight ; drug effects ; Drug Synergism ; Eating ; drug effects ; Fenofibrate ; pharmacology ; Hypoglycemic Agents ; pharmacology ; Hypolipidemic Agents ; pharmacology ; Insulin Resistance ; Lipids ; blood ; Lipoprotein Lipase ; genetics ; metabolism ; Liver ; drug effects ; Metabolic Syndrome ; chemically induced ; metabolism ; pathology ; Mice ; Mice, Inbred ICR ; RNA, Messenger ; metabolism ; Sodium Glutamate ; Thiazolidinediones ; pharmacology

The aim of this study is to investigate the protection effect of tanshinone IIA (Tan) against triptolide (TP)-induced liver injury and the mechanisms involved. Acute liver injury was induced by intraperitoneal injection of TP (1 mg x kg(-1)) in mice. The activities of AST, ALT and LDH in serum and the levels of GSH, GST, GSH-PX, SOD, CAT and MDA in liver tissue were detected. The histopathological changes of liver tissues were observed after HE staining. Nrf2 translocation in liver tissue was detected by Western blotting, and real-time PCR was used to measure the expression levels of GCLC, NQO1 and HO-1 mRNA. The results showed that pretreatment with Tan significantly prevented the TP induced liver injury as indicated by reducing the activities of AST, ALT and LDH (P < 0.01). Tan pretreatment also prevented TP-induced oxidative stress in the mice liver by inhibiting MDA and restoring the levels of GSH, GST, SOD and CAT (P < 0.05). Parallel to these changes, pretreatment with Tan could attenuate histopathologic changes induced by TP. Furthermore, the results indicated that Tan pretreatment caused nuclear accumulation of Nrf2 as well as induction of mRNA expression of antioxidant response element (ARE)-driven genes such as GCLC, NQO1 and HO-1. These results indicated that Tan could protect against TP-induced acute liver injury via the activation of Nrf2/ARE pathway.
Animals ; Antioxidant Response Elements ; drug effects ; Chemical and Drug Induced Liver Injury ; metabolism ; pathology ; Diterpenes ; toxicity ; Diterpenes, Abietane ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Epoxy Compounds ; toxicity ; Glutamate-Cysteine Ligase ; genetics ; metabolism ; Heme Oxygenase-1 ; genetics ; metabolism ; Liver ; metabolism ; pathology ; Male ; Membrane Proteins ; genetics ; metabolism ; Mice ; Mice, Inbred C57BL ; NAD(P)H Dehydrogenase (Quinone) ; genetics ; metabolism ; NF-E2-Related Factor 2 ; metabolism ; Phenanthrenes ; toxicity ; RNA, Messenger ; metabolism ; Signal Transduction ; drug effects