The Effect of Curcuma phaeocaulis Valeton (Zingiberaceae) Extract on Prion Propagation in Cell-Based and Animal Models.

Prion diseases are neurodegenerative disorders in humans and animals for which no therapies are currently available. Here, we report that Curcuma phaeocaulis Valeton (Zingiberaceae) (CpV) extract was partly effective in decreasing prion aggregation and propagation in both in vitro and in vivo models. CpV extract inhibited self-aggregation of recombinant prion protein (PrP) in a test tube assay and decreased the accumulation of scrapie PrP (PrPSc) in ScN2a cells, a cultured neuroblastoma cell line with chronic prion infection, in a concentration-dependent manner. CpV extract also modified the course of the disease in mice inoculated with mouse-adapted scrapie prions, completely preventing the onset of prion disease in three of eight mice. Biochemical and neuropathological analyses revealed a statistically significant reduction in PrPSc accumulation, spongiosis, astrogliosis, and microglia activation in the brains of mice that avoided disease onset. Furthermore, PrPSc accumulation in the spleen of mice was also reduced. CpV extract precluded prion infection in cultured cells as demonstrated by the modified standard scrapie cell assay. This study suggests that CpV extract could contribute to investigating the modulation of prion propagation.

Maclurin exerts anti-cancer effects on PC3 human prostate cancer cells via activation of p38 and inhibitions of JNK, FAK, AKT, and c-Myc signaling pathways.

Maclurin is a phenolic compound extracted from purple mangosteen and mulberry twigs. Earlier reports indicated that it exerts antioxidant activity. We hypothesized that maclurin exerts antioxidant activity and anti-cancer effects in small cell neuroendocrine carcinomas (SCNCs), a very aggressive type of human prostate cancer. To verify our hypothesis, we selected PC3 cells as a model system and investigated the antioxidant activity and anti-cancer effects of maclurin. In the reactive oxygen species (ROS) detection assay for the verification of antioxidant activity, we observed the unexpected prooxidant activity of maclurin in PC3 cells. For the anti-cancer activities, we investigated the effects of maclurin on induction of apoptosis and inhibition of metastatic characteristics of PC3 cells. In the apoptosis assay, maclurin significantly induced apoptosis of PC3 cells. Maclurin also showed significant anti-metastatic effects. Maclurin inhibited cell migration in a dosage-dependent manner. In addition, the gelatin zymography assay indicated that maclurin inhibited activities of matrix metalloproteinase-2 and 9 (MMP-2 and MMP-9) that affect cell migration and extracellular matrix (ECM) degradation. Then, we investigated the effects of maclurin on the cancer-related signaling molecules. Maclurin activated p38 signaling and inhibited c-Jun N-terminal kinase (JNK), focal-adhesion kinase (FAK), AKT, and c-Myc signalings in PC3 cells. Finally, we observed prooxidant activity and anti-SCNC effects of maclurin in DU145 cells. This suggests that the effects of maclurin may not be specifically limited to PC3 cells. Our findings suggest that maclurin exerts anti-cancer effects on SCNC cells via activation of p38 and inhibitions of JNK, FAK, AKT and c-Myc signalings.

AP-1-Targeting Anti-Inflammatory Activity of the Methanolic Extract of Persicaria chinensis.

In traditional Chinese medicine, Persicaria chinensis L. has been prescribed to cure numerous inflammatory disorders. We previously analyzed the bioactivity of the methanol extract of this plant (Pc-ME) against LPS-induced NO and PGE2 in RAW264.7 macrophages and found that it prevented HCl/EtOH-induced gastric ulcers in mice. The purpose of the current study was to explore the molecular mechanism by which Pc-ME inhibits activator protein- (AP-) 1 activation pathway and mediates its hepatoprotective activity. To investigate the putative therapeutic properties of Pc-ME against AP-1-mediated inflammation and hepatotoxicity, lipopolysaccharide- (LPS-) stimulated RAW264.7 and U937 cells, a monocyte-like human cell line, and an LPS/D-galactosamine- (D-GalN-) induced acute hepatitis mouse model were employed. The expression of LPS-induced proinflammatory cytokines including interleukin- (IL-) 1ß, IL-6, and tumor necrosis factor-α (TNF-α) was significantly diminished by Pc-ME. Moreover, Pc-ME reduced AP-1 activation and mitogen-activated protein kinase (MAPK) phosphorylation in both LPS-stimulated RAW264.7 cells and differentiated U937 cells. Additionally, we highlighted the hepatoprotective and curative effects of Pc-ME pretreated orally in a mouse model of LPS/D-GalN-intoxicated acute liver injury by demonstrating the significant reduction in elevated serum AST and ALT levels and histological damage. Therefore, these results strongly suggest that Pc-ME could function as an antihepatitis remedy suppressing MAPK/AP-1-mediated inflammatory events.