New steroidal saponins from the aerial parts of Paris polyphylla var. yunnanensis and their effects on blood coagulation.

Five new steroidal saponins, paripolins D-H (1-5), and 6 known compounds (6-11) were isolated from the aerial parts of Paris polyphylla var. yunnanensis. The structures of 1-5 were determined using spectroscopic analyses in conjunction with acid hydrolysis. It is for the first time to report the 12-hydroxysteroidal saponins from the genus Paris. The effect of all isolated compounds on blood coagulation was determined in vitro using the plasma recalcification time method. Compounds 1 and 2 showed potent procoagulant activity, and 5-11 exhibited significant anticoagulant activity.

Inhibition of PTEN activity promotes IB4-positive sensory neuronal axon growth.

Traumatic nerve injuries have become a common clinical problem, and axon regeneration is a critical process in the successful functional recovery of the injured nervous system. In this study, we found that peripheral axotomy reduces PTEN expression in adult sensory neurons; however, it did not alter the expression level of PTEN in IB4-positive sensory neurons. Additionally, our results indicate that the artificial inhibition of PTEN markedly promotes adult sensory axon regeneration, including IB4-positive neuronal axon growth. Thus, our results provide strong evidence that PTEN is a prominent repressor of adult sensory axon regeneration, especially in IB4-positive neurons.

c-Myc controls the fate of neural progenitor cells during cerebral cortex development.

The anatomical structure of the mammalian cerebral cortex is the essential foundation for its complex neural activity. This structure is developed by proliferation, differentiation, and migration of neural progenitor cells (NPCs), the fate of which is spatially and temporally regulated by the proper gene. This study was used in utero electroporation and found that the well-known oncogene c-Myc mainly promoted NPCs' proliferation and their transformation into intermediate precursor cells. Furthermore, the obtained results also showed that c-Myc blocked the differentiation of NPCs to postmitotic neurons, and the expression of telomere reverse transcriptase was controlled by c-Myc in the neocortex. These findings indicated c-Myc as a key regulator of the fate of NPCs during the development of the cerebral cortex.

Quercetin inhibits growth of hepatocellular carcinoma by apoptosis induction in part via autophagy stimulation in mice.

Quercetin (QCT) has been shown to have anticancer activities associated with apoptosis and autophagy induction. However, whether autophagy is functionally responsible for the inhibitory effect of QCT on hepatocellular carcinoma (HCC) remains elusive. This study aims to investigate if QCT inhibits HCC growth via autophagy induction. The in vitro experiments showed that QCT inhibited the growth of human HCC cells in dose- and time-dependent manners and had minimal cytotoxicity to normal hepatocytes. QCT increased both autophagosomes and autolysosomes in HCC cells, as determined by electron microscopy, GFP-RFP-LC3 fluorescence confocal microscopy and Western blot analysis of autophagy-related biomarkers. Functional assays using pathway-specific inhibitors, activators or siRNAs indicated that QCT stimulated autophagy in part via inhibiting the AKT/mTOR pathway and activating the MAPK pathways. Further functional experiments using autophagy inhibitors demonstrated that QCT induced apoptosis of HCC cells in part via stimulating autophagy. The in vivo studies showed that QCT significantly inhibited tumor growth associated with apoptosis induction and autophagy stimulation, and that inhibition of autophagy significantly alleviated the QCT effect on tumor growth inhibition and apoptosis induction. To the best of our knowledge, this is the first in vivo report to demonstrate that QCT inhibits HCC tumor growth and induces apoptosis in part via stimulation of autophagy. Our results provide strong experimental evidence to support that autophagy stimulation may be an important mechanism by which QCT induces cancer cell apoptosis, and pave the way for further clinical investigations by applying QCT or QCT-rich foods for HCC intervention.

Regulation of adult mammalian intrinsic axonal regeneration by NF-κB/STAT3 signaling cascade.

The inflammatory response is a critical regulator for the regeneration of axon following nervous system injury. Nuclear factor-kappa B (NF-κB) is characteristically known for its ubiquitous role in the inflammatory response. However, its functional role in adult mammalian axon growth remains elusive. Here, we found that the NF-κB signaling pathway is activated in adult sensory neurons through peripheral axotomy. Furthermore, inhibition of NF-κB in peripheral sensory neurons attenuated their axon growth in vitro and in vivo. Our results also showed that NF-κB modulated axon growth by repressing the phosphorylation of STAT3. Furthermore, activation of STAT3 significantly promoted adult optic nerve regeneration. Taken together, the findings of our study indicated that NF-κB/STAT3 cascade is a critical regulator of intrinsic axon growth capability in the adult nervous system.

6-Gingerol inhibits proliferation in gastric cancer via the STAT3 pathway in vitro.

With high incidence and mortality, gastric cancer seriously threatened human's life. It is arduous and necessary to investigate its pathogenesis and dig effective drugs. In this study, we explored the role of 6-Gingerol (GI), a natural active ingredient, in treating gastric cancer cells. MTT assay and colony formation assay were utilized to confirmed that GI can control the proliferation of gastric cancer cells, which is time and concentration-dependent to some extent. The Annexin V-FITC/PI staining results by flow cytometry reveal that GI induces the apoptosis of gastric cancer cells. And a study on further pathways by western blot shows that GI brings about cell apoptosis by inhibiting the activation of STAT3. GI therefore may be a good candidate for treating gastric cancer.

Rosemary Extracts Upregulate Nrf2, Sestrin2, and MRP2 Protein Level in Human Hepatoma HepG2 Cells.

In the past few decades, the incidence of liver cancer has been rapidly rising across the world. Rosemary is known to possess antioxidant activity and is used as natural antioxidant food preservative. It is proposed to have anticancer activity in treating different tumor models. In this study, we try to explore the impact of rosemary extracts on upregulating the level of Nrf2 and Nrf2-regulatory proteins, Sestrin2 and MRP2 in HepG2 cells, and to speculate its potential mechanism. The anticancer activity of rosemary extract, including its polyphenolic diterpenes carnosic acid and carnosol, was evaluated to understand the potential effect on HepG2 cells. Rosemary extract, carnosic acid, and carnosol induced the expression of Sestrin2 and MRP2 associate with enhancement of Nrf2 protein level in HepG2 cells, in which carnosic acid showed most obvious effect. Although the activation pathway of Nrf2/ARE was not exactly assessed, it can be assumed that the enhancement of expression of Sestrin2 and MRP2 may result from upregulation of Nrf2.

5-Hydroxymethylfurfural protects against ER stress-induced apoptosis in GalN/TNF-α-injured L02 hepatocytes through regulating the PERK-eIF2α signaling pathway.

5-Hydroxymethylfurfural (5-HMF), a water-soluble compound extracted from wine-processed Fructus corni, is a novel hepatic protectant for treating acute liver injury. The present study was designed to investigate the protective effect of 5-HMF in human L02 hepatocytes injured by D-galactosamine (GalN) and tumor necrosis factor-α (TNF-α) in vitro and to explore the underlying mechanisms of action. Our results showed that 5-HMF caused significant increase in the viability of L02 cells injured by GalN/TNF-α, in accordance with a dose-dependent decrease in apoptotic cell death confirmed by morphological and flow cytometric analyses. Based on immunofluorescence and Western blot assays, we found that GalN/TNF-α induced ER stress in the cells, as indicated by the disturbance of intracellular Ca(2+) concentration, the activation of protein kinase RNA (PKR)-like ER kinase (PERK), phosphorylation of eukaryotic initiation factor 2 alpha (eIF2α), and expression of ATF4 and CHOP proteins, which was reversed by 5-HMF pre-treatment in a dose-dependent manner. The anti-apoptotic effect of 5-HMF was further evidenced by balancing the expression of Bcl-2 family members. In addition, the knockdown of PERK suppressed the expression of phospho-PERK, phospho-eIF2α, ATF4, and CHOP, resulting in a significant decrease in cell apoptosis after the treatment with GalN/TNF-α. 5-HMF could enhance the effects of PERK knockdown, protecting the cells against the GalN/TNF-α insult. In conclusion, these findings demonstrate that 5-HMF can effectively protect GalN/TNF-α-injured L02 hepatocytes against ER stress-induced apoptosis through the regulation of the PERK-eIF2α signaling pathway, suggesting that it is a possible candidate for liver disease therapy.

CGRP inhibits norepinephrine induced apoptosis with restoration of Bcl-2/Bax in cultured cardiomyocytes of rat.

Calcitonin gene related peptide (CGRP) and norepinephrine (NE) may interact in acute myocardial ischemia, protecting cardiomyocytes but the underlying mechanism is unclear. Here we investigated the correlation of the anti-apoptotic effect of CGRP with the change of Bcl-2/Bax. Cultured cardiomyocytes were divided into four groups: (1) control group (no treatment with any test agent), (2) NE group (treated with 10(-5)mol/L of NE), (3) CGRP+NE group (treated with 10(-8)mol/L of CGRP and NE at 10(-5)mol/L) and (4) CGRP8-37+CGRP+NE group (treated with 10(-7)mol/L of CGRP8-37, a specific antagonist of CGRP receptor, CGRP at 10(-8)mol/L and NE at 10(-5)mol/L). Apoptosis ratio was analyzed by flow cytometry. Bcl-2 and Bax and the coding mRNA were examined. It was found that the apoptosis ratio in NE group (29.4 ± 1.8%) was significantly greater (P<0.05) than that of the control group (10.1 ± 1.7%). The effect of NE was attenuated by CGRP (18.7 ± 2.1%), which was reversed by CGRP8-37 (24.9 ± 2.9%). NE treatment resulted in reductions in the ratio of Bcl-2/Bax (by 33%) and their mRNA (by 53%). CGRP restored the level of Bcl-2/Bax, which was abolished by CGRP8-37. Current study suggests that norepinephrine inhibits synthesis of Bcl-2 and increases Bax and apoptosis of cardiomyocytes. CGRP restores the ratio of Bcl-2/Bax and attenuates the apoptosis induced by NE, via specific CGRP receptor.

In vitro anticancer property of a novel thalidomide analogue through inhibition of NF-kappaB activation in HL-60 cells.

AIM: To investigate the anticancer property and possible mechanism of action of a novel sugar-substituted thalidomide derivative (STA-35) on HL-60 cells in vitro. METHODS: TNF-alpha-induced NF-kappaB activation was determined using a reporter gene assay. The MTT assay was used to measure cytotoxicity of the compound. The appearance of apoptotic Sub-G1 cells was detected by flow cytometry analysis. PARP cleavage and protein expression of NF-kappaB p65 and its inhibitor IkappaB were viewed by Western blotting. RESULTS: TA-35 (1-20 micromol/L) suppressed TNF-alpha-induced NF-kappaB activation in transfected cells (HEK293/pNiFty-SEAP) in a dose- (1-20 micromol/L) and time-dependent (0-48 h) manner. It was also shown that STA-35 exerted a dose-dependent inhibitory effect on HL-60 cell proliferation with an IC(50) value of 9.05 micromol/L. In addition, STA-35 induced apoptosis in HL-60 cells, as indicated by the appearance of a Sub-G1 peak in the cell cycle distribution, as well as poly ADP-ribose polymerase (PARP) cleavage. Subsequently, both NF-kappaB p65 and its inhibitor IkappaB gradually accumulated in cytoplasmic extracts in a dose- and time-dependent manner, indicating the blockage of NF-kappaB translocation induced by TNF-alpha from the cytoplasm to the nucleus. CONCLUSION: A novel sugar-substituted thalidomide derivative, STA-35, is potent toward HL-60 cells in vitro and induces apoptosis by the suppression of NF-kappaB activation.

An anticancer effect of a new saponin component from Gymnocladus chinensis Baillon through inactivation of nuclear factor-kappaB.

Gymnocladus chinensis Baillon is widely distributed in China, and its fruits have been used in the treatment of rheumatism, furunculosis, soreness and swelling in traditional Chinese medicine for a long time. Few biological components were, however, isolated. In this study, a new triterpenoid saponin (GC-1) was extracted from the fruit of Gymnocladus chinensis Baillon and its biological actions were investigated. The results showed that GC-1 inhibited growth of a panel of human cancer cell lines in vitro by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide and sulforhodamine B assays. Furthermore, GC-1 was demonstrated to induce apoptosis in HL-60 cells in a dose-dependent manner. By using a reporter gene assay, nuclear factor-kappaB activity induced by tumor necrosis factor-alpha was decreased gradually by addition of increasing concentration of GC-1 (1-40 micromol/l). In parallel, the blockage of nuclear factor-kappaB translocation from cytoplasm to nucleus was determined by Western blotting. This is the first study investigating the link of antiproliferative action of the compound with the inhibition of nuclear factor-kappaB activation. The mechanism of the actions of GC-1 might be due to the interruption of nuclear factor-kappaB translocation in the signaling pathway, which contributes to the chemotherapy potential.