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Artemisia sacrorum Ledeb. was extracted by 95% ethanol and water, respectively. By partitioning the 95% ethanol extract successively with different solvents and separating the water extract by macroporous resin, nine separate parts were obtained. According to the results of in vitro experiments, the CH2Cl2 (dichloromethane) fraction showed the most pronounced cytotoxic activity against HepG2, HT-29 and MCF-7 cells, with EC50 values 122.35, 49.76 and 28.51 µg mL−1, respectively, at 48 h. Following this, the compounds of the CH2Cl2 fraction were separated and identified. Ten compounds were isolated from A. sacrorum Ledeb. and identified by spectral analysis. Four compounds, including acacetin, were isolated for the first time from A. sacrorum Ledeb. [ABSTRACT FROM AUTHOR]

Based upon preliminary study showing stimulation of glucose uptake by 20( R)-Rg, a stereoisomer of 20( S)-Rg ginsenoside found in red ginseng, we investigated the action mechanism of 20( R)-Rg in differentiated C2C12 myotubes. It was found that 20( R)-Rg stimulated translocation of glucose transporter 4 (GLUT4) and glucose uptake in a concentration-dependent manner. In addition, 20( R)-Rg phosphorylated AMP-activated protein kinase (AMPK) and Ca/Calmodulin-dependent protein kinase kinase (CaMKK) in time- and concentration-dependent manners. In the meantime, 20( R)-Rg-induced glucose uptake and translocation of GLUT4 were attenuated in the presence of compound C (an AMPK inhibitor) or STO-609 (a CaMKK inhibitor). Taken together, this study is the first to demonstrate that 20( R)-Rg stimulated the glucose uptake via translocation of GLUT4 and this effect was seemed to be mediated by CaMKK-AMPK pathways in C2C12 myotubes. [ABSTRACT FROM AUTHOR]

In this study, we investigated the protective effects of fermented ginseng (FG) on hyperglycemia induced by streptozotocin (STZ) in Sprague Dawley rats. FG was administered orally at dose of 250 (FGL) or 500 mg/kg (FGH) for 20 days starting one week before STZ injection. FG restored the plasma insulin levels by 266% and 334% in FGL and FGH, respectively, and resulting in reduction of plasma glucose concentration. Histological observation indicated that STZ-induced destruction of pancreatic islets was protected by FG. Consistent with this observation, FG reduced protein and mRNA levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), as determined by Western blotting and RT-PCR, respectively. The molecular mechanism of FG's inhibition of iNOS and COX-2 gene expressions appeared to involve the inhibition of nuclear factor-κB (NF-κB) activation via prevention of inhibitor κB (IκB) phosphorylation and degradation. The cytoprotective effects of FG were also mediated through suppression of extracelluar signal-regulated kinase (ERK) and c-JUN N-terminal kinase (JNK) pathways. Collectively, these results suggest that FG might be used to preserve functional β-cell mass. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Corosolic acid (CA) is the main active component of Lagetstroemia speciosa and has been known to serve as several different pharmacological effects, such as antidiabetic, anti-oxidant, and anticancer effects. In this study, effects of CA on the hepatic lipid accumulation were examined using HepG2 cells and tyloxapol (TY)-induced hyperlipidemia ICR mice. CA significantly inhibited hepatic lipid accumulation via inhibition of SREBPs, and its target genes FAS, SCD1, and HMGCR transcription in HepG2 cells. These effects were mediated through activation of AMPK, and these effects were all abolished in the presence of compound C (CC, an AMPK inhibitor). In addition, CA clearly alleviated serum ALT, AST, TG, TC, low-density lipoprotein cholesterol (LDL-C), and increased high-density lipoprotein cholesterol (HDL-C) levels, and obviously attenuated TY-induced liver steatosis and inflammation. Moreover, CA significantly upregulated AMPK, ACC, LKB1 phosphorylation, and significantly inhibited lipin1, SREBPs, TNF- α , F4/80, caspase-1 expression, NF- κ B translocation, and MAPK activation in TY-induced hyperlipidemia mice. Our results suggest that CA is a potent antihyperlipidemia and antihepatic steatosis agent and the mechanism involved both lipogenesis and cholesterol synthesis and inflammation response inhibition via AMPK/SREBPs and NF- κ B/MAPK signaling pathways.

Ginsenoside Re is a protopanaxatriol-type saponin isolated from Panax ginseng berry. Although anti-diabetic and anti-hyperlipidemic effects of Re have been reported by several groups, its mechanism of action is largely unknown until now. Here, we examine anti-diabetic and anti-hyperlipidemic activities of Re and action mechanism(s) in human HepG2 hepatocytes and high-fat diet fed C57BL/6J mice. Re suppresses the hepatic glucose production via induction of orphan nuclear receptor small heterodimer partner (SHP), and inhibits lipogenesis via suppression of sterol regulatory element binding protein-1c (SREBP-1c) and its target gene [fatty acid synthase (FAS), stearoyl-CoA desaturase-1 (SCD1)] transcription. These effects were mediated through activation of AMP-activated protein kinase (AMPK), and abolished when HepG2 cells were treated with an AMPK inhibitor, Compound C. C57BL/6J mice were randomly divided into five groups: regular diet fed group (RD), high-fat diet fed group (HFD) and the HFD plus Re (5, 10, 20 mg/kg) groups. Re treatment groups were fed a high-fat diet for 6 weeks, and then orally administered Re once a day for 3 weeks. The in vitro results are likely to hold true in an in vivo experiment, as Re markedly lowered blood glucose and triglyceride levels and protected against hepatic steatosis in high-fat diet fed C57BL/6J mice. In conclusion, the current study suggest that ginsenoside Re improves hyperglycemia and hyperlipidemia through activation of AMPK, and confers beneficial effects on type 2 diabetic patients with insulin resistance and dyslipidemia.

As part of our search for biologically active anti-osteoporotic agents that enhance differentiation and mineralization of osteoblastic MC3T3-E1 cells, we identified the ginsenoside Rh2(S). Mostly known to exhibit beneficial effects in cancer prevention and metabolic diseases, Rh2(S) is one of the most active ginsenosides. Here, we show that Rh2(S) stimulates osteoblastic differentiation and mineralization, manifested by the up-regulation of differentiation markers (alkaline phosphatase and osteogenic genes) and von Kossa/Alizarin Red staining, respectively. Rh2(S) also activated protein kinase D (PKD) and AMP-activated protein kinase (AMPK) in a time- and concentration-dependent manner, and Rh2(S)-induced differentiation and mineralization of osteoblastic cells were significantly abolished in the presence of specific inhibitors; Go6976 for PKD and Ara-A for AMPK. Furthermore, Go6976 suppressed Rh2(S)-mediated activation of AMPK, indicating that PKD may be an upstream signal for AMPK in Rh2(S)-induced differentiation and mineralization of MC3T3-E1 cells. Taken together, these results indicate that Rh2(S) induces the differentiation and mineralization of MC3T3-E1 cells through activation of PKD/AMPK signaling pathways. These findings provide a molecular basis for the osteogenic effect of Rh2(S).

Artemisia sacrorum Ledeb. (Compositae) (ASL) has long been used in Oriental folk medicine to treat diverse hepatic diseases. In this study, we investigated the effect of ASL on adipocyte differentiation in 3T3-L1 cells. ASL significantly suppressed 3T3-L1 differentiation in a concentration-dependent manner. A significant increase of AMP-activated protein kinase (AMPK) was observed when the cells were treated with ASL. Activation of AMPK was also demonstrated by measuring the phosphorylation of acetyl-CoA carboxylase, a substrate of AMPK. These effects were abolished by pre-treatment with the AMPK inhibitor, compound C. In addition, ASL down-regulated the adipogenesis-related gene expression of the sterol regulatory element-binding protein 1c (SREBP1c) and its target genes, such as fatty acid synthase (FAS), stearoyl-CoA desaturase 1 (SCD1) and glycerol-3-phosphate acyltransferase (GPAT) in a concentration-dependent manner. These effects were abolished by pre-treatment with compound C. ASL significantly reduced the gene expression of the peroxisome proliferator-activated receptor γ (PPARγ) and of the CCAAT/enhancer binding protein-α (C/EBPα), two key transcription factors in adipogenesis. Meanwhile, adipocyte fatty acid binding protein (aP2) gene expression was also reduced in a concentration-dependent manner. These findings indicated that ASL exerts anti-adipogenic activity via AMPK activation and may act to prevent obesity.

In this study, we investigated the effects of a petroleum ether fraction of Artemisia sacrorum Ledeb. (Compositae) (PEASL) on glucose production through AMP-activated protein kinase (AMPK) activation in human HepG2 cells. PEASL significantly inhibited glucose production in a concentration-dependent manner, and this effect was reversed in the presence of compound C, a selective AMPK inhibitor. PEASL markedly induced the phosphorylation of AMPK and downstream acetyl-CoA carboxylase (ACC) in a time- and concentration-dependent manner. In addition, it markedly increased the phosphorylations of glycogen synthase kinase 3β (GSK3β) in a concentration-dependent manner. In contrast, cAMP response element binding protein (CREB), a key transcription factor for gluconeogenic enzyme phosphorylation, decreased in a concentration-dependent manner. PEASL downregulated the gluconeogenesis gene expression of peroxisome proliferation activated receptor-γ coactivator-1α (PGC-1α), phosphoenolpyruvate carboxykinase (PEPCK), and glucose-6-phosphatase (G6Pase) in a concentration-dependent manner. In addition, the gene expression of orphan nuclear receptor small heterodimer partner (SHP) increased, also in a concentration-dependent manner. These effects were also abolished by pretreatment with compound C, an AMPK inhibitor. This indicates that PEASL inhibited glucose production via the AMPK-GSK-CREB pathway in HepG2 cells, and these effects appeared to be capable of revealing anti-diabetic mechanism of PEASL in HepG2 cells.

20(S)-ginsenoside Rg3 [20(S)-Rg3)], one of the main constituents isolated from Panax ginseng, has been shown to have an anti-cancer effect and to induce apoptosis by interfering with several signaling pathways. However, the molecular mechanisms of AMP-activated protein kinase (AMPK) associated with apoptosis in HT-29 colon cancer cells remain unclear. In the present study, we investigated whether 20(S)-Rg3 exerts an anti-proliferative effect and induces apoptosis by modulating the AMPK signaling pathway in HT-29 cells. 20(S)-Rg3-treated cells displayed several apoptotic features, including DNA fragmentation, proteolytic cleavage of poly (ADP-ribose) polymerase (PARP) and morphological changes. 20(S)-Rg3 down-regulated the expression of anti-apoptotic protein B-cell CLL/lymphoma 2 (Bcl2), up-regulated the expression of pro-apoptotic protein of p53 and Bcl-2-associated X protein (Bax), and caused the release of mitochondrial cytochrome c, PARP, caspase-9 and caspase-3. However, 20(S)-Rg3-induced apoptosis was completely abolished in the presence of compound C (AMPK inhibitor) or small interfering RNA for AMPK (siAMPK). In addition, STO-609 (CaMKKβ inhibitor) attenuated 20(S)-Rg3-induced AMPK activation and apoptosis. These results suggest that 20(S)-Rg3-induced apoptosis in HT-29 cells is mediated via the AMPK signaling pathway, and that 20(S)-Rg3 is capable of inducing apoptosis in colon cancer.

In this study, we investigated the protective effects of fermented ginseng (FG) on hyperglycemia induced by streptozotocin (STZ) in Sprague Dawley rats. FG was administered orally at dose of 250 (FGL) or 500 mg/kg (FGH) for 20 days starting one week before STZ injection. FG restored the plasma insulin levels by 266% and 334% in FGL and FGH, respectively, and resulting in reduction of plasma glucose concentration. Histological observation indicated that STZ-induced destruction of pancreatic islets was protected by FG. Consistent with this observation, FG reduced protein and mRNA levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), as determined by Western blotting and RT-PCR, respectively. The molecular mechanism of FG's inhibition of iNOS and COX-2 gene expressions appeared to involve the inhibition of nuclear factor-kappaB (NF-kappaB) activation via prevention of inhibitor kappaB (IkappaB) phosphorylation and degradation. The cytoprotective effects of FG were also mediated through suppression of extracelluar signal-regulated kinase (ERK) and c-JUN N-terminal kinase (JNK) pathways. Collectively, these results suggest that FG might be used to preserve functional beta-cell mass.

Ginseng (Panax ginseng C.A. Meyer) is widely used in Asian countries as a traditional medicine for the treatment of various diseases. It is known to have anti-inflammatory effects, although the mechanism is not clear. In this study, preventive effects of fermented ginseng (FG) against streptozotocin (STZ)-induced pancreatic beta-cell death was assessed in RINm5F insulinoma cells. FG markedly inhibited the production of nitrite in a dose-dependent manner. The decrease in nitrite production was found to correlate with reduced inducible nitric oxide (iNOS) protein and mRNA levels. To characterize the anti-inflammatory mechanism of FG at the transcriptional level, we examined effects of FG on the activity of nuclear factor-kappaB (NF-kappaB). FG reduced a translocation of the NF-kappaB subunit and NF-kappaB-dependent transcriptional activity. FG blocked signaling upstream of NF-kappaB activation, such as degradation of inhibitor factor-kappaBalpha (IkappaBalpha ) and phosphorylations of extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK). These results suggest that FG protects against STZ-induced pancreatic beta-cell damage by downregulation of iNOS, cyclooxygenase-2 (COX-2), and tumor necrosis factor-alpha (TNF-alpha ) gene expressions by blocking NF-kappaB and mitogen-activated protein kinase activities.

Artemisia sacrorum Ledeb. (Compositae) (ASL) is a traditional Chinese medicine used to treat different hepatic diseases. However, a hypolipidemic effect of ASL on fatty liver disease has not been reported. Therefore, we investigated whether 95% ethanol eluate (EE), an active part of ASL, would attenuate hepatic lipid accumulation in human HepG2 cells by activating AMP-activated protein kinase (AMPK). Significant decreases in triglyceride levels and increases in AMPK and acetyl-CoA carboxylase (ACC) phosphorylation were observed when the cells were treated with 95% EE. EE down-regulated the lipogenesis gene expression of sterol regulatory element-binding protein 1c (SREBP1c) and its target genes, such as fatty acid synthase (FAS) and stearoyl-CoA desaturase 1 (SCD1), in a time- and dose-dependent manner. In contrast, the lipolytic gene expression of peroxisome proliferator-activated receptor alpha (PPAR-alpha) and CD36 increased in a time- and dose-dependent manner. These effects were abolished by pretreatment with compound C, an AMPK inhibitor. However, there were no differences in the gene expression of SREBP2, low density lipoprotein receptor (LDLR), hydroxymethyl glutaryl CoA reductase (HMG-CoA), or glucose transporter 2 (GLUT2). At the same time, 95% EE significantly increased the gene expression of acyl CoA oxidase (ACOX) in a time- and dose-dependent manner. Thus, AMPK mediated 95% EE induced suppression of SREBP1c and activation of PPAR-alpha respectively. These finding indicate that 95% EE attenuates hepatic lipid accumulation through AMPK activation and may be active in the prevention of serious diseases such as fatty liver, obesity, and type-2 diabetic mellitus.

This study was designed to investigate the protective effects of the active part of Artemisia sacrorum Ledeb. Extract (ASE) against acetaminophen (APAP)-induced hepatotoxicity in mice. As a result, pretreated with ASE prior to the administration of APAP significantly prevented the increases of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and tumor necrosis factor-alpha (TNF-alpha) levels in serum, and glutathione (GSH) depletion, malondialdehyde (MDA) accumulation in liver tissue. In addition, ASE prevented APAP-induced apoptosis and necrosis, as indicated by a liver histopathological analysis and DNA laddering. Furthermore, according to the results from Western blot analysis, ASE markedly decreased APAP-induced caspase-3 and -8 protein expressions in mouse livers. All these results suggest that the protective effects of ASE against APAP-induced liver injury may involve mechanisms associated with its inhibitive effects of lipid peroxidation and the down-regulation of TNF-alpha mediated apoptosis.