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Dioscorea bulbifera L., a traditionally used medicinal plant in China, is reported to induce hepatotoxicity. The present study is designed to investigate the protection of an ethanol extract of Angelica sinensis (Oliv) Diels (AE) against an ethyl acetate fraction of D. bulbifera (EF)-induced liver injury and its engaged mechanism. High performance liquid chromatography (HPLC) analysis showed that the amount of diosbulbin B in EF was 16.03% and ferulic acid in AE was 0.18%. EF (350 mg/kg) increased serum alanine/aspartate aminotransferase (ALT/AST), alkaline phosphatase (ALP) activities and total bilirubin (TB) amount, while AE inhibited such an increase. Liver histological evaluation showed that AE prevented development of severe hepatic lesions induced by EF. Further results showed that EF decreased the expression of Bcl-2 and induced the cleaved activation of caspase-9 and -3, and all those effects were reversed by AE. AE also reversed EF-induced decreased expression of the inhibitor of kappa B (IκB), superoxide dismutase (SOD), and glutathione peroxidase (GPx). Taken together, our results demonstrate that AE can prevent EF-induced hepatotoxicity via preventing apoptosis, meanwhile IκB, SOD, and GPx may be involved in such protection.

Catalpol is a natural iridoid glycoside with diverse bioactivities that is found in abundance in Rehmannia glutinosa Libosch. (Scrophulariaceae). The present study assessed whether catalpol treatment (5, 10, or 20 mg/kg for 14 days by intragastric administration (i.g.)) has an antidepressant-like effect on mice performing the forced swim test (FST), tail suspension test (TST), open field test (OFT), and tests for reversal of reserpine-induced ptosis, akinesia, and hypothermia. This study also examined the potential role that catalpol plays in the cerebral monoaminergic system. Results indicated that catalpol administration produced an antidepressant-like effect in mice, as indicated by the reduced duration of immobility in the FST and TST, but it had no effect on locomotor activity in the OFT. Catalpol treatment significantly counteracted the decrease in rectal temperature, akinesia, and eyelid ptosis induced by reserpine. Moreover, catalpol increased levels of serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the brains of mice, but it did not affect levels of norepinephrine (NE) or dopamine (DA). These antidepressant-like effects of catalpol are essentially similar to the effects of the clinical antidepressant fluoxetine hydrochloride (FH). This is the first study to indicate that catalpol has an antidepressant-like effect and that its action may be mediated by the central serotonergic system, and not by noradrenergic or dopaminergic systems.

Lysimachia christinae Hance (Primulaceae) is a medicinal plant. The present study was undertaken to investigate protection of L. christinae against acute alcohol-induced liver injury in mice, the related mechanism of oxidative stress and its hepatoprotective chemical compound for the first time. Mice were orally administered alcohol at 6 g/kg 2 h after a 75% ethanol extract of L. christinae (ET) (100, 200, 400 mg/kg), quercetin (2, 4, 8 mg/kg) isolated from L. christinae, or bifendate (150 mg/kg) for seven consecutive days by intragastric administration (i.g.) except the normal group. Serum and liver tissue samples were collected 6 h after alcohol administration and the amount of quercetin in ET was analyzed by high-performance liquid chromatography (HPLC) with a diode array detector (DAD). The results showed that alcohol-induced elevated serum alanine transferase (ALT) and aspartate transaminase (AST) activities were significantly reduced by ET (200, 400 mg/kg), quercetin (4, 8 mg/kg) and bifendate (150 mg/kg), respectively. Further analysis demonstrated that lipid peroxidation (LPO) levels significantly decreased, while glutathione amounts, glutathione-s transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) activities all increased in livers of ET-, quercetin-, and bifendate-treated mice. Besides, amount of quercetin in ET was 1.03%. Taken together, our results indicate that L. christinae can protect against acute alcohol-induced liver injury in mice, the potential mechanism can be related to inhibiting liver oxidative stress injury, and its main hepatoprotective compound is quercetin, for the first time.

Dioscorea bulbifera L. is a medicinal plant. The present study was undertaken to investigate the hepatotoxicity induced by D. bulbifera in mice. Through the acute toxicity of various extracts including the EtOAc fraction (EF) and the non-EtOAc fraction (Non-EF) from ethanol, and the ethanol itself, we found that the EF contains the toxic ingredients of D. bulbifera rhizome. On this basis, to study the hepatotoxicity induced by the toxic ingredients, mice were treated with 0.5% sodium carboxymethyl cellulose (CMC-Na) alone or the EF of D. bulbifera rhizome at doses of 80, 160, 320, and 480 mg/kg once daily i.g. for fourteen consecutive administrations. Serum samples were collected for determination of the biomarkers for liver injury, such as, alanine transaminase (ALT) and aspartate transanimase (AST). Hepatic tissues were used to assay for the level of lipid peroxide (LPO), amounts of antioxidants such as glutathione, and activities of antioxidant-related enzymes for liver oxidative-antioxidative status in mice. The results showed that ALT and AST were significantly elevated after fourteen consecutive administrations of the EF of D. bulbifera rhizome. In addition, the level of LPO increased remarkably, while the glutathione amounts, and the activities of the antioxidant-related and glutathione-related enzymes including superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione-S-transferase (GST), glutathione reductase (GR) and glutamate-cysteine ligase (GCL) of hepatic tissues all decreased conspicuously, in livers of mice treated with the EF of D. bulbifera rhizome. Taken together, our results indicate that the EF contains the main toxic ingredients of D. bulbifera rhizome, and the mechanism of hepatotoxicity induced by it may be due to liver oxidative stress injury in mice.

Extensive efforts have been made to determine the status on neural progenitor cell proliferation in specific pathological conditions and to evaluate the therapeutic efficacy of drugs for preventing neurogenic deficits in neurodegenerative diseases. However, the most commonly used stereological analysis using 5-bromo-2′-deoxyuridine (BrdU) immuno-positive sections is a time consuming and labor intensive process and is often a bottle neck in neurogenic drug development, particularly when large sample sizes are needed. In addition, BrdU is toxic to new born neurons and also labels DNA damage in old cells. In this study, we established a method that quantitatively measures the number of Ki-67, an endogenous cell proliferation marker, positive cells by flow cytometry which analyzes extracted cell nuclei from rodent hippocampi in suspension. Our results demonstrate that this approach can be applied to a large number of rodent samples, can be accomplished in a short period of time (1-3 days), and can be completed in a more accurately objective manner than by using 3-D cell counting with immunohistochemically processed sections.