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The enhanced inhibitory effect of paclitaxel (PTX) combined with hypericin (HY) on B16-F10 cells may be realized through the ROS-related cytochrome c release pathway. The apoptotic characteristics of the B16-F10 cells, such as DNA fragmentation, chromatin condensation, and apoptotic body formation, were all enhanced in the combined treatment group. Further investigation showed that the combination of paclitaxel and HY could increase the level of mitochondrial damage and the concentration of cytochrome c, causing the expression of caspase-3 and the cleavage of PARP.1. Compared with paclitaxel or HY alone, the level of reactive oxygen species (ROS) increased significantly, while glutathione reductase (GR) activity and intracellular glutathione (GSH) levels decreased significantly in the combination group.

Objectives The combination of gemcitabine (Gem) and hypericin (HY) enhances the apoptosis of Capan-2 cells, providing a promising option for the treatment of pancreatic cancer. Our study further explored the cytotoxic mechanism of HY combined with chemotherapy drugs on pancreatic cancer. Methods The proliferation rate of the cells assayed with the MTT method. The ROS (reactive oxygen species) levels of each treatment were evaluated by DCFH-DA oxidisation methods. The activity of glutathione reductase and the levels of reduced glutathione (GSH) and oxidised glutathione (GSSG) were assessed using assay kits. The expression levels of apoptosis-related proteins were analysed by western blotting. Key findings The activity of glucose-6-phosphate dehydrogenase (G6PDH), a key enzyme of the pentose phosphate pathway, significantly decreased in Gem + HY groups, however, the ROS level enhanced accompanying with GSH depleting, mitochondrial membrane depolarisation and cytochrome C release. Gem + HY inhibits the expression of Bcl-2 but stimulates Bax level, triggering caspase activation and PARP cleavage and thus promoted apoptosis of Capan-2 cells. Conclusions We demonstrated that Gem combined HY-PDT could inhibit the proliferation of Capan-2 cells and induce cell apoptosis. HY-PDT combined with Gem had a great potential on pancreatic cancer treatment clinically.

As part of our program to discover new bioactive agents from endophytic fungi, three new indole alkaloids (1–2, 4) along with twelve known compounds were isolated from an inset derived endophytic strain Aspergillus lentulus. Their structures were determined by comprehensive spectroscopic analyses of 1D/2D NMR and HR-ESI-MS data. The absolute configurations were confirmed by ECD calculation using Time-dependent Density functional theory (TD-DFT) at the B3LYP/6–31 + g (d, p) level and Rh2(OCOCF3)4-induced ECD experiments. Compounds 2, 4, 5, 13 and 15 exhibited moderate cytotoxic effects on A549 cell line with IC50 in the range of 17.92–48.29 μM. Compounds 1, 2 and 13–15 displayed the anti-bacterial activity against Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola with MIC values ranging from 25 to 100 μg/mL.

A dATP conversion E. coli strain could be constructed when both pyk and adk1 gene were expressed successfully. pyk gene encodes pyruvate kinase (PK) could be expressed, when inserted it before adk1 gene which encodes adenylate kinase (AK) in plasmid pET-pyk-adk1 after transform into E. coli and the recombinant could be used to convert dATP from dAMP. Another plasmid pET-adk1-pyk, which inserted pyk gene behind of adk1, the recombinant E. coli transformed with this plasmid could not convert dAMP into dATP, pyk gene cannot be translated in this recombinant. The different translation levels of pyk with gene location switching caused mainly by the different secondary structures formed by the 5’-untranslation regions and the gene sequence of its5’-terminal. The dATP product E. coli strain could be constructed when cloned pyk gene at an optimum location.

From the cultured cells of Panax notoginseng, a kind of ginseng saponin-ginsenoside Rg2, was separated and purified, and its structure was elucidated as 6-O-[alpha-L-rhamnose (l-->2)-beta-D-glucopyranosyl]3beta, 12beta, 20(S)-trihydroxydammar-24-ene [20(S)-ginsenoside Rg2]. Moreover, its bioactivity stimulates human umbilical cord vein endothelial cell proliferation; the growth of the cells treated with 20(S)-ginsenoside Rg2 was 14-fold higher than that of untreated ones, and the level of the cell's plasminogen activator (PA) was also twofold higher.

Ginseng saponins 20( S )-ginsenoside Rg 2 extracted from cultured Panax notoginseng cells in a fermenter show a protection effect on human umbilical cord vein endothelial cells (VEC-304) from H 2 O 2 -induced cell apoptosis. When 50 μg/ml 20( S )-ginsenoside Rg 2 was present in the culture medium for 8 h, the H 2 O 2 -damaged VEC-304 cells acquired about 11-fold ( p p 2 has a strong ability in scavenging intracellular ROS induced by H 2 O 2 .

Reactive oxygen species are believed to play a role in the development of several diseases including vascular diseases and the aging process. It is reported that increased reactive oxygen species were implicated as an important mechanism that contributes to endothelial dysfunction. So, human umbilical cord vein endothelial cells were used to study the antioxidative effect of L-ascorbic acid and its derivative. The study indicated that L-ascorbic acid as a traditional antioxidant was instable and could protect the cells against hydrogen peroxide induced cytotoxicity as its concentration below 50 microg/ml, but hardly could protect the cells against tert-butyl hydroperoxide induced cytotoxicity. Ascorbic acid-2-o-phosphate-6-o-palmitate could effectively protect the cells against hydrogen peroxide and tert-butyl hydroperoxide induced cytotoxicity, and exhibited no cytotoxicity within the tested concentration range. The study indicated that ascorbic acid-2-o-phosphate-6-o-palmitate could not only significantly reduce the intracellular reactive oxygen species level in 3 h culture, but also increase the cell viability in 15 h culture. In addition, ascorbic acid-2-o-phosphate-6-o-palmitate could keep stable in RPMI-1640 medium and water for 4 days, permeate the cell membrane, which in turn may scavenge the intracellular reactive oxygen species, increase the cell viability and the plasminogen activators'activity. All the above results suggested that addition of some hydrophobic groups to the traditional antioxidants could form novel compounds with better properties.

AP-2 transcription factors are important sequence-specific DNA-binding regulators that are expressed in the neural crest and other tissues during mammalian development. The human AP-2 family of transcription factors consists of five members, AP-2α, -β, -γ, -δ and -e, which have an important role in the regulation of gene expression during development and in the differentiation of multiple organs and tissues. The present study aimed to investigate the mechanism by which AP-2δ mediates heme oxygenase-1 (HMOX1) gene expression. It was identified that the human AP-2δ protein exhibited weak binding to a suboptimal AP-2 sequence, 5'-GCCN3GGC-3', to which all other AP-2 proteins bind in vitro, providing the first example of DNA target specificity amongst the AP-2 family. AP-2δ protein bound to an optimized AP-2 consensus DNA sequence, 5'-GCCTGAGGC-3', in vitro and transactivated gene expression in eukaryotic cells. The transactivation domain of Ap-2δ differs notably from those in the other AP-2 proteins as it lacks the PY motif (XPPXY) and several other conserved residues that are important for the transcriptional activity of AP-2 proteins, yet it functions as an equally strong activator.

To improve the bioactivity of recombinant (r)Hirudin, the orthogonal pair MjBTyrRS/tRNATyr cua (made up of the boronophenylalanine, tRNA and tRNA synthetase), was selected to incorporate boronophenylalanine site‑specifically into rHirudin at the 63 sites in an Escherichia coli system in response to the TAG codon. Following fusion with the gIII signal peptide and a hexahistidine tag, the modified protein was secreted into Luria‑Bertani culture medium and purified by nickel-nitrilotriacetic acid affinity chromatography following a gel filtration column. In a 200 ml flask, the yield of boronophenylalanine‑modified hirudin was 10 mg l‑1 and that of rHirudin was 19 mg l‑1. The authenticity of the purified proteins was verified using matrix-assisted laser desorption ionization time of flight mass spectroscopy and antithrombin activity assays. The results revealed that the antithrombin activity of the boronophenylalanine‑modified hirudin to human thrombin was more enhanced than that of rHirudin. The modified hirudin demonstrated stronger proliferation inhibiting ability on fibroblast L929 cells compared with that of rHirudin.

Some degradation products from lignocellulose pretreatment strongly inhibit the activities of cellulolytic enzymes and ethanol fermentation strains, thus the efficient removal of the inhibitor substances ("detoxification") is the inevitable step for the biotransformation processes. In this study, the biological detoxification of furfural by a newly isolated fungus, Amorphotheca resinae ZN1, was studied and the metabolic pathways of furfural degradation was analyzed. The metabolic pathway of furfural degradation in A. resinae ZN1 was described as follows: first, furfural was quickly converted into the low toxic furfuryl alcohol; then the furfuryl alcohol was gradually converted into furfural again but under the low concentration under aerobic condition, which was not lethal to the growth of the fungi; furfural continued to be oxidized to furoic acid by A. resinae ZN1. It is likely that furoic acid was further degraded in the TCA cycle to complete the biological degradation of furfural. The present study provided the important experimental basis for speeding up the biodetoxification of furfural by A. resinae ZN1 and the rate-limiting step in the lignocellulose biotransformation to ethanol.

We describe a modified single nucleotide polymorphism (SNP) typing method based on the restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR). This is a simple, economical method without the need for special equipment. For most SNP loci, a common restriction endonuclease (Hind III, EcoR I or BamH I) recognizing site (RER) can be introduced into one allelic form, but not the other by two rounds of mismatched PCR. The flanking regions can be changed by as many as five bases after PCR amplification with specially designed mismatching primers so the genotypes can be distinguished after digestion of the PCR products with corresponding endonucleases.

In order to investigate whether the variances in the candidate genes (Insulin receptor substrate IRS-1, beta3-adrenergic receptor ADRB3, 3 beta-hydro-xysteroid dehydrogenase HSD3B2, glucocorticoid receptor GRL and 21-hydroxylase CYP21) which affect the metabolism of adrenal steroids hormone and body composition, are associated with precocious puberty in Chinese girls.PCR-RFLP analysis method was applied in the typing of six activity SNPs in five genes in two groups: 176 precocious puberty girls as case and 192 healthy girls as control.The typing results showed that the frequencies of the allele CYP21 L282 polymorphism were 32.7% and 32.6% in case and control groups (P=0.518), respectively. For IRS-1 R972, they were 0.6% in cases and 2.3% in controls (P=0.043), for ADRB3 R64, 13.6% in cases and 12% in controls (P=0. 378), and for GRL S363, 7.4% in cases and 5.73% in controls (P=0.335). No sample in the two groups carries the variation of CYP21 I172N and HSD3B2 L236S.Among these six activity SNPs in five candidate genes, IRS-1 972R was statistically associated with the onset time of puberty in Chinese girls. In order to confirm whether the candidate genes have any other activity SNPs that are associated with the onset time of puberty in Chinese girls, resequencing of these candidate genes is needed in following time.

CYP3A4 plays an important role in the metabolism of a variety of endogenous and exogenous compounds. Earlier studies revealed that a high-activity variation of the CYP3A4 gene, CYP3A4*1B is significantly associated with the precocious puberty in girls. Other three variations, CYP3A4*4, CYP3A4*5 and CYP3A4*6, which were found in a study carried out in a Chinese population in Taiwan, were reported to down-regulate the enzymatic activity of CYP3A4. The four activity SNPs were typed in our study in two groups of Chinese girls: 176 girls with precocious puberty as the case group, and 192 normal girls as the control group. No variations of CYP3A4*1B and CYP3A4*4 were found in all the cases and controls. Heterozygous of CYP3A4*5 was found in five subjects of the 192 controls but none in the cases, heterozygous of CYP3A4*6 was found in two subjects of the controls but none in the cases. Fisher's exact test showed that the variation of CYP3A4*5 was associated with the onset of puberty in Chinese girls (P-trend = 0.038), while the variation of CYP3A4*6 was not associated with the onset of puberty in Chinese girls (P-trend = 0.272). The result suggests that these mutations in the CYP3A4 gene have no contribution to the early onset of puberty in Chinese girls, but are related in some way with the puberty development in Chinese girls.