Evaluating the antioxidant activity of secondary metabolites of endophytic fungi from Hypericum perforatum L. by an electrochemical biosensor based on AuNPs/AC@CS composite.

Due to the variety and activity of secondary metabolites of endophytic fungi (SMEF) from medicinal plants, and the operation cumbersome of existing methods for evaluating the activity, there is urgent to establish a simple, efficient and sensitive evaluation and screening technology. In this study, the prepared chitosan functionalized activated carbon (AC@CS) composite as the electrode substrate material was used to modify glassy carbon electrode (GCE), and the gold nanoparticles (AuNPs) was deposited on AC@CS/GCE by cyclic voltammetry (CV). A ds-DNA/AuNPs/AC@CS/GCE electrochemical biosensor for evaluating the antioxidant activity of SMEF from Hypericum perforatum L. (HP L.) was fabricated using the method of layer by layer assembly. The experimental conditions affecting the evaluation results of the biosensor were optimized by square wave voltammetry (SWV) using Ru(NH3)63+ as the probe, and the antioxidant activity of various SMEF from HP L. was evaluated by the proposed biosensor. Meanwhile, the results of the biosensor were also verified by UV-vis. According to the optimized experimental results, the biosensors had a high levels of oxidative DNA damage at pH 6.0 and Fenton solution system with Fe2+ to OH- ratio of 1:3 for 30 min. Among the crude extracts of SMEF from roots, stems and leaves of HP L., the crude extracts from stems presents a high antioxidant activity, but it was weaker than l-ascorbic acid. This result was consistent with the evaluation results of UV-vis spectrophotometric method, also the fabricated biosensor presents high stability and sensitivity. This study not only provides a novel, convenient and efficient way for rapid evaluating the antioxidant activity of a wide variety of SMEF from HP L., but also provides a novel evaluation strategy for the SMEF from medicinal plants.

Potential Anti-Tumor Activity of Nardoguaianone L Isolated from Nardostachys jatamansi DC. in SW1990 Cells.

Natural products (NPs) were a rich source of diverse bioactive molecules. Most anti-tumor agents were built on natural scaffolds. Nardostachys jatamansi DC. was an important plant used to process the traditional Chinese herbal medicines "gansong". Pancreatic cancer was the fourth most common cause of cancer-related death in the world. Hence, there was an urgent need to develop novel agents for the treatment of pancreatic cancer. In this paper, nardoguaianone L (G-6) is isolated from N. jatamansi, which inhibited SW1990 cells colony formation and cell migration, and induced cell apoptosis. Furthermore, we analyzed the differential expression proteins after treatment with G-6 in SW1990 cells by using iTRAQ/TMT-based quantitative proteomics technology, and the results showed that G-6 regulated 143 proteins' differential expression by GO annotation, including biological process, cellular component, and molecular function. Meanwhile, KEGG enrichment found that with Human T-cell leukemia virus, one infection was the most highly enhanced pathway. Furthermore, the MET/PTEN/TGF-ß pathway was identified as a significant pathway that had important biological functions, including cell migration and motility by PPI network analysis in SW1990 cells. Taken together, our study found that G-6 is a potential anti-pancreatic cancer agent with regulation of MET/PTEN/TGF-ß pathway.

Chemical constituents from the roots of Zanthoxylum bungeanum Maxim. and their neuroprotective activities.

Twenty-two isolates, including two previously undescribed compounds identified as benzoyltembamide (1) and P-benzoyphenethyl anisate (21), were isolated and identified from a methanol extract of the roots of Zanthoxylum bungeanum Maxim. (Rutaceae) using diverse chromatographic materials and pre-HPLC. Their structures were elucidated on the basis of spectroscopic and spectrometric data analysis such as HR-ESI-MS, 1D and 2D NMR, IR and UV, as well as single-crystal X-ray diffraction for crystalline compounds. All the compounds (except for compound 16) were isolated from the roots of Z. bungeanum for the first time. Selected compounds were evaluated for their antioxidant activities. Compound 18 attenuated the H2O2-induced cytotoxicity and blocked the accumulation of ROS in SH-SY5Y cells, and exhibited potent neuroprotective activity.

Dammarane triterpenoids with rare skeletons from Gynostemma pentaphyllum and their cytotoxic activities.

Three unreported dammarane-type triterpenoids with rare skeletons (1-3), along with one undescribed gypenoside (4), were isolated from the aerial parts of Gynostemma pentaphyllum using diverse chromatographic materials and pre-HPLC. Their structures were elucidated on the basis of spectroscopic and spectrometric data, while the absolute configurations of 1-3 were assessed via electronic circular dichroism (ECD) analyses. Notably, compounds 1-3 possess a 3,19-hemiketal bridge in the A ring. Saponin 4 possesses an unreported 20,25-oxa structural moiety. Their antiproliferative effects against HepG2, MCF-7, and DU145 cell lines were screened. Compounds 1-3 displayed moderate cytotoxicity with IC50 values ranging from 13.7 ± 0.2 to 32.0 ± 1.7 µM.

Antioxidant defenses and non-specific immunity at enzymatic and transcriptional levels in response to dietary carbohydrate in a typical carnivorous fish, hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂).

The present study was conducted to explore the influence of dietary carbohydrate on antioxidant capacity and non-specific immunity of hybrid grouper, which would contribute to determine the tolerable dietary carbohydrate content. Seven diets with grade levels of carbohydrate (5.27, 8.95, 11.49, 14.37, 17.78, 20.82 and 23.65%) were fed to triplicate groups of fish for 10 weeks. Results showed that the inclusion of carbohydrate above 11.49% produced significant increased content of hydrogen peroxide (H2O2) in liver and malondialdehyde (MDA) in both serum and liver. The specific activity of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (Gpx) and total antioxidative capacity (T-AOC) were significantly elevated with the increase of dietary carbohydrate from 8.95 to 23.65%, which may be associated with the reduced hepatic soluble protein content. However, opposite variation was observed in the expression of antioxidant related genes (SOD1 and Gpx), which was partly caused by the activation of NF-E2-related factor 2 (Nrf2) and inhibition of Kelch-like-ECH-associated protein 1 (Keap1) at the transcriptional level. The immunoglobulin M (lgM) content and activity of lysozyme and CCP in serum significantly depressed when dietary carbohydrate was above 11.49%. The expression of pro-inflammatory cytokines (TNF-α, IL-1ß and IL-8) was significantly increased with the increase of dietary carbohydrate from 5.27 to 8.95% and thereafter significantly reduced, which was consistent with the changed expression of toll-like receptor 2 (TLR2) and nuclear factor κΒ (NF-κΒ). In above, high dietary carbohydrate significantly impaired the antioxidant capacity and reduced the non-specific immunity of hybrid grouper, and the tolerable dietary carbohydrate content should not exceed 11.49%.

Newly synthesized podophyllotoxin derivative, LJ12, induces apoptosis and mitotic catastrophe in non-small cell lung cancer cells in vitro.

Deoxypodophyllotoxin (DPT), an active compound isolated from a number of herbs and used in traditional medicine, has been reported to exhibit promising anti­tumor activity. A newly synthesized derivative, N-(1-oxyl­4'-demethyl-4-deoxyp odophyllic)-L­methine-4'-piperazine carbamate (LJ12) may have improved antitumor activity and fewer side effects. The present study assessed the effect of LJ12 on cell viability, apoptosis, cell cycle distribution and mitotic catastrophe in A549 human lung cancer cells in vitro. The molecular mechanisms underlying the antitumor activity of LJ12 were also examined. The results demonstrated that LJ12 reduced A549 cell viability in a time­ and dose­dependent manner, with a lower half maximal inhibitory concentration of ~0.1 µM, compared with another known DPT derivative, etoposide (10 µM). Flow cytometric analysis showed that LJ12 induced tumor cell arrest at the G2/M phase of the cell cycle. The present study also observed an expected concomitant decrease in the numbers of cells cells in the G0/G1 and S phases. LJ12 was found to upregulate the protein expression levels of Cdc2 and Cyclin B1. Furthermore, LJ12 induced tumor cell apoptosis and the protein expression of B cell lymphoma­2­associated X protein, caspase­3 and p53. The present study also observed the formation of giant, multinucleated cells, indicating that LJ12 induced mitotic catastrophe in the tumor cells. These results indicated that LJ12 has anti­non­small cell lung cancer activity in vitro. Further investigations aim to develop LJ12 as a therapeutic agent for the treatment of lung cancer.

DPMA, a deoxypodophyllotoxin derivative, induces apoptosis and anti-angiogenesis in non-small cell lung cancer A549 cells.

We found that the deoxypodophyllotoxin derivative, 2,6-dimethoxy-4-(6-oxo-(5R,5aR,6,8,8aR,9-hexahydrofuro[3',4':6,7]naphtho[2,3-d][1,3]dioxol-5-yl)phenyl ((R)-1-amino-4-(methylthio)-1-oxobutan-2-yl)carbamate (DPMA), exhibited superior cytotoxicity compared with etoposide. In this study, we investigated the mechanism of action of DPMA. DPMA exhibited anti-proliferative activity and induced apoptosis in A549 cells in a dose- and time-dependant manner. DPMA inhibited microtubule formation and induced expression of Bax, cleaved caspase-3, p53 and ROS, and inhibited Bcl-2 expression. DPMA also affected cyclinB1, cdc2 and p-cdc2 expression, inducing cell cycle arrest. DPMA also inhibited tube formation of VEGF-induced human umbilical vein endothelial cells. These studies demonstrate that DPMA inhibits p53/cdc2/Bax signaling, thereby inhibiting cell growth/angiogenesis and inducing apoptosis.

Synthesis and evaluation of the cell cycle arrest and CT DNA interaction properties of 4ß-amino-4'-O-demethyl-4-deoxypodophyllotoxins.

A series of 4ß-amino-4'-O-demethyl-4-deoxypodophyllotoxin derivatives were synthesized, and their cytotoxicities against several human cancer cell lines, including HepG2, A549, HeLa and HCT-8 cells, evaluated. Some of these compounds exhibited higher levels of cytotoxicity than the anticancer drug etoposide. 4ß-N-(4-Nitrophenyl piperazinyl)-4'-O-demethyl-4-deoxypodophyllotoxin (11) was found to be the most potent synthesized compound in the current study, and induced cell cycle arrest in the G2/M phase in HeLa cells, which was accompanied by apoptosis. Furthermore, this compound activated the expression of cdc2, cyclin B1, p53 and caspase-3 in HeLa cells, leading to changes in the conformation of calf thymus DNA from the B-form to a more compact C-form.