Recent Progress in Ferroptosis Induced Tumor Cell Death by Anti-tumor Metallic complexes.

Metal complexes represented by platinum complexes play a very important role in cancer treatment due to their diverse chemical structures and anti-tumor activities. Recently, ferroptosis has emerged as a newly occurring cell death form in the anti-tumor process. It has been reported that metal complexes could inhibit the proliferation and metastasis of tumors and combat chemotherapy resistance by targeting ferroptosis. In this review, we briefly describe ferroptosis as a fundamental process for tumor suppression and triggering anti-tumor immune responses. We summarize recent developments on metal complexes that induce ferroptosis. Finally, we outline the prospects for the application of metal complexes to the treatment of tumors based on ferroptosis and the associated problems that need to be solved, and discussed other potential research directions of metal complexes.

The recombinant protein combined vaccine based on the fragment C of tetanus toxin and the cross-reacting material 197.

Diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccines were widely used since 1940s. The exceptional success of childhood vaccination is undisputed. However, the anti-diphtheria and tetanus antibody will decrease with the increase of age in human body. A boosting vaccine for tetanus and diphtheria in adult is recommended by WHO. Recombinant protein vaccine has the advantages of single component and high safety, which is one of the directions to develop boosting vaccines. Therefore, in this study, we evaluated a recombinant TTc and CRM197 combination vaccine (RTCV) that uses the fragment C (TTc) of tetanus toxin and the cross-reacting material 197 (CRM197) of the diphtheria toxin mutant. Our results displayed that RTCV (composed of 10 µg/mL TTc, 20 µg/mL CRM197 antigens, and 500 µg/mL aluminum adjuvants) could induce high levels of IgG and IgG1 antibody in mice, which were similar as those induced by DTaP. These results will provide technical support for a novel boosting vaccine against diphtheria and tetanus. KEY POINTS: • We successfully expressed CRM197 protein in E. coli BL21 (DE3) using pET26b (+) vector. • The anti-TTc and anti-CRM197 antibody titer (IgG) of RTCV was similar with DTaP.

Optimization and mechanism of postponing aging of polysaccharides from Chinese herbal medicine formula.

To study the extraction technology of polysaccharides (AAP) from Chinese herbal medicine formula and its mechanism of delaying aging. First, L9(3)4 orthogonal test was used to optimize the optimal enzyme-assisted extraction parameters of polysaccharides. And the anti-aging effects was evaluated by detecting mitochondrial function, protein, DNA, adhesion molecules and cell cycle in aging rats. The optimal extraction process parameters were the cellulase concentration of 1.5%, the pH at 5, the enzyme temperature at 50°C and the extraction time of 180 min. The anti-aging results showed that AAP can effectively increase the activities of malate dehydrogenase, succinate dehydrogenase and superoxide dismutase. It also can decrease the activity of monoamine oxidase and methane dicarboxylic aldehyde levels in the brain tissue. Meanwhile, the polysaccharides enhanced telomerase activity while reduced p16 protein expression of the brain mitochondria. In addition, the polysaccharides continued to improve heart damage and significantly lessen mitochondrial DNA concentrations. For a certain period of time, it also enhanced the activity of superoxide dismutase, reduced glutathione, glutathione peroxidase and decreased protein carbonyl and methane dicarboxylic aldehyde content of kidney in D-galactose-induced aging rats. Furthermore, the polysaccharides restored the number of cells in the peripheral blood lines and BMNC through inhibiting the drop of the number of red blood cells, white blood cells, platelets in the peripheral blood and bone marrow mononuclear cell of the aging rats. At the same time, AAP accelerated G1 phase cell to enter S phase in cell cycle in aging rats. Our research suggests that the polysaccharides may be a potential anti-aging agent and can be further developed as a functional food or new drug to delay aging or treat aging-related diseases.

Expression and Purification of Tetanus Toxin Fragment C in Escherichia coli BL21(DE3).

BACKGROUND: Tetanus is an infectious disease caused by Clostridium secreting tetanus toxin in anaerobic environment. The fragment C of Tetanus toxin (TTc) has been widely studied as a candidate vaccine to replace the existing tetanus toxoid vaccine. OBJECTIVE: In this study, we established a simple method to purify recombinant protein TTc with ion-exchange chromatography from Escherichia coli expression systems. METHODS: The TTc gene sequence was cloned into pET26b (+) vector and transferred to E. coli BL21 (DE3) for expression. The fermentation conditions (IPTG concentration, Induction temperature, Induction time) were optimized to obtain more soluble proteins. The soluble proteins were purified by Anion exchange chromatography and Cation exchange chromatography. The sequence of columns in the purification process was discussed. Finally, the stability of purified TTc protein were determined, the secondary structure of the purified TTc protein was determined by circular dichroism. The molecular weight of the purified TTc protein was determined by liquid chromatograph- mass spectrometer. Furthermore, we verified the immunogenicity of the purified protein in mice. RESULTS: The purity of TTc improved from 34% to 88% after the first anion exchange column, and the final yield of recombinant TTc (purity > 95%) can reach 84.79% after the following cation exchange chromatography. The recombinant TTc had a molecular weight of 51.737 KDa, was stable at 4 °C and weak alkaline environment, was a ß-sheet secondary structure, and had strong immunogenicity. CONCLUSION: The purification method we developed might be an efficient method for the industrial production of tetanus recombinant TTc vaccine.

Pulsed electromagnetic fields promote bone formation by activating the sAC-cAMP-PKA-CREB signaling pathway.

The application of pulsed electromagnetic fields (PEMFs) in the prevention and treatment of osteoporosis has long been an area of interest. However, the clinical application of PEMFs remains limited because of the poor understanding of the PEMF action mechanism. Here, we report that PEMFs promote bone formation by activating soluble adenylyl cyclase (sAC), cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), and cAMP response element-binding protein (CREB) signaling pathways. First, it was found that 50 Hz 0.6 millitesla (mT) PEMFs promoted osteogenic differentiation of rat calvarial osteoblasts (ROBs), and that PEMFs activated cAMP-PKA-CREB signaling by increasing intracellular cAMP levels, facilitating phosphorylation of PKA and CREB, and inducing nuclear translocation of phosphorylated (p)-CREB. Blocking the signaling by adenylate cyclase (AC) and PKA inhibitors both abolished the osteogenic effect of PEMFs. Second, expression of sAC isoform was found to be increased significantly by PEMF treatment. Blocking sAC using sAC-specific inhibitor KH7 dramatically inhibited the osteogenic differentiation of ROBs. Finally, the peak bone mass of growing rats was significantly increased after 2 months of PEMF treatment with 90 min/day. The serum cAMP content, p-PKA, and p-CREB as well as the sAC protein expression levels were all increased significantly in femurs of treated rats. The current study indicated that PEMFs promote bone formation in vitro and in vivo by activating sAC-cAMP-PKA-CREB signaling pathway of osteoblasts directly or indirectly.

Snakegourd root/Astragalus polysaccharide hydrogel preparation and application in 3D printing.

Hydrogels have good water retention, biocompatibility and biodegradability, so they are well used in the medical industry. Here, we have active polysaccharide exacted from Chinese traditional medicine and carboxymethyl chitosan cross-linked to form hydrogel and characterized them by Scanning electron microscopy, FTIR analysis, swelling, degradation, release and cytotoxicity tests. We printed the composite hydrogel into patches with three different shapes by Hot-Melt extruded 3D printer and studied the effects of different shapes on the release of drug. The results show, under acidic or alkaline conditions, the BSA cumulative release rate of the three hydrogel patches with different shape range from 49% to 89%. Therefore, there is a significant difference in the release between circular, cube and rectangular shape. Through the study, we found that the hydrogels we prepared have excellent potential for future applications in drug delivery system.

A novel therapeutic vaccine composed of a rearranged human papillomavirus type 16 E6/E7 fusion protein and Fms-like tyrosine kinase-3 ligand induces CD8+ T cell responses and antitumor effect.

The development of cervical cancer is mainly caused by infection with high risk genotypes of human papillomavirus, particularly type 16 (HPV16), which accounts for more than 50% of cervical cancer. The two early viral oncogenes, E6 and E7, are continuously expressed in cervical cancer cells and are necessary to maintain the malignant cellular phenotype, thus providing ideal targets for immunotherapy of cervical cancer. In this study, a novel vaccine strategy was developed based on a rationally shuffled HPV16 E6/E7 fusion protein, the addition of Fms-like tyrosine kinase-3 ligand (Flt3L) or the N domain of calreticulin (NCRT), and the usage of a CpG adjuvant. Four recombinant proteins were constructed: m16E6E7 (mutant E6/E7 fusion protein), rm16E6E7 (rearranged mutant HPV16 E6/E7 fusion protein), Flt3L-RM16 (Flt3L fused to rm16E6E7), and NCRT-RM16 (NCRT fused to rm16E6E7). Our results suggest that Flt3L-RM16 was the most potent of these proteins in terms of inducing E6- and E7-specific CD8+ T cell responses. Additionally, Flt3L-RM16 significantly induced regression of established E6/E7-expressing TC-1 tumors. Higher doses of Flt3L-RM16 trended toward higher levels of antitumor activity, but these differences did not reach statistical significance. In summary, this study found that Flt3L-RM16 fusion protein is a promising therapeutic vaccine for immunotherapy of HPV16-associated cervical cancer.

Research progress of therapeutic vaccines for treating chronic hepatitis B.

Hepatitis B virus (HBV) is a member of Hepadnavirus family, which leads to chronic infection in around 5% of patients with a high risk of developing liver cirrhosis, liver failure, and hepatocellular carcinoma. 1 Despite the availability of prophylactic vaccines against hepatitis B for over 3 decades, there are still more than 2 billion people have been infected and 240 million of them were chronic. Antiviral therapies currently used in the treatment of CHB (chronic hepatitis B) infection include peg-interferon, standard α-interferon and nucleos/tide analogs (NAs), but none of them can provide sustained control of viral replication. As an alternative strategy, therapeutic vaccines for CHB patients have been widely studied and showed some promising efficacies in dozens of preclinical and clinical trials. In this article, we review current research progress in several types of therapeutic vaccines for CHB treatment, including protein-based vaccines, DNA-based vaccines, live vector-based vaccines, peptide-based vaccines and cell-based therapies. These researches may provide some clues for developing new treatments in CHB infection.

Synthesis and Pharmacological Evaluation of Novel Pleuromutilin Derivatives with Substituted Benzimidazole Moieties.

A series of novel pleuromutilin derivatives with substituted benzimidazole moieties were designed and synthesized from pleuromutilin and 5-amino-2-mercaptobenzimidazole through sequential reactions. All the newly synthesized compounds were characterized by IR, NMR, and HRMS. Each of the derivatives was evaluated in vitro for their antibacterial activity against Escherichia coli (E. coli) and five Gram (+) inoculums. 14-O-((5-amino-benzimidazole-2-yl) thioacetyl) mutilin (3) was the most active compound and showed highest antibacterial activities. Furthermore, we evaluated the inhibition activities of compound 3 on short-term S. aureus and MRSA growth and cytochrome P450 (CYP). The bioassay results indicate that compound 3 could be considered potential antibacterial agents but with intermediate inhibition of CYP3A4.

Structural characterization and antioxidant activity in vitro of polysaccharides from angelica and astragalus.

In the present study, structural characterization and antioxidant activity of a fraction (AAP-2A) of polysaccharides from angelica and astragalus (AAP) were investigated. Characteriztion assay showed that AAP-2A had molecular weight (Mw), root-mean square (RMS) radius and polydispersity index (Mw/Mn) of 2.252 × 10(3)kDa, 28.4 nm and 1.038, respectively. There were infrared characteristic absorption peaks of polysaccharides in FT-IR spectroscopy. AAP-2A was composed of rhamnose (Rha), galactose (Gal), arabinose (Ara) and glucose (Glc) with a molar ratio of 1:2.13:3.22:6.18 in GC analysis. Methylation analysis combined with NMR spectroscopic analysis demonstrated that a preliminary structure of AAP-2A was proposed as follows: 1,3-linked Rhap, 1,3-linked Galp, 1,3-linked Araf, 1,5-linked Araf, 1,3,5-linked Araf, 1,4-linked Glcp and 1,4,6-linked Glcp interspersed with terminal Glcp. AAP-2A exhibited a surface with a sheet-like appearance in scanning electron microscope and stronger antioxidant capacity compared with AAP.

[Optimization of Enzymatic Hydrolysis Conditions of Xiaoyao-pill Herb Residues by Cellulase].

Objective: To explore the enzymatic hydrolysis conditions of Xiaoyao-pill herb residues by cellulose. Methods: Based on the single factor test,an Box-Benhnken design was used to optimize the parameters, three factors, including cellulase dosage, enzymolysis time, and solid-liquid ratio were regarded as investigation factors,the yield of enzymatic hydrolysis as index, Xiaoyao-pill herb residues enzymatic hydrolysis catalyzed by cellulase, and a mathematical regression model was established. Results: The optimal parameters were obtained as follows,cellulase dosage was 6%,enzymolysis time was 5. 6 h and solid-liquid ratio was 1 ∶ 12( g / m L). Under this condition,the yield of enzymatic hydrolysis was 43. 89%. Conclusion: The results may provide new reference for further exploring Chinese herbal medicine efficiently.

Guiqi polysaccharide protects the normal human fetal lung fibroblast WI-38 cells from H2O2-induced premature senescence.

OBJECTIVE: This study is to investigate the effects of Guiqi polysaccharide (GQP) on H2O2-induced premature senescence in normal human fetal lung fibroblast WI-38 cells. METHODS: WI-38 cells were subjected to treatments of GQP, Angelica sinensis polysaccharide (ASP), and Astragalus membranaceus polysaccharide (AMP), and then treated with H2O2 to induce premature senescence. Morphological observation, MTT assay, senescence-associated ß-galactosidase activity assessment, telomerase activity determination, cell cycle analysis, and Western blot analysis were performed to evaluate cellular senescence. RESULTS: H2O2 treatment induced premature senescence in WI-38 cells, as indicated by the decreased fibroblast proliferation activity and changed cellular morphology. When treated with GQP, ASP, or AMP, the morphological changes in WI-38 cells induced by H2O2 could be restored. SA-ß-gal activity was elevated in H2O2-treated WI-38 cells, which could be decreased by GQP treatment. Moreover, compared with the normal control, H2O2 treatment significantly inhibited the telomerase activity of WI-38 cells. However, GQP effectively elevated the telomerase activity of these senescent cells. Furthermore, flow cytometry and cell cycle analysis showed that GQP treatment could abrogate the cell cycle arrest in H2O2-treated WI-38 cells, which might contribute to the anti-senescent effects. In addition, GQP significantly affected the p53-p21 and p16-pRb pathways in H2O2-treated WI-38 cells. The effectiveness of GQP was superior to AMP or ASP treatment alone. CONCLUSION: GQP has protective effects in oxidative stress-induced senescence. Our findings suggest the promising role of GQP as an attractive and bio-safe agent with the potential to retard senescence and attenuate senescence-related diseases.

Polysaccharides from Angelica and Astragalus exert hepatoprotective effects against carbon-tetrachloride-induced intoxication in mice.

This study aimed to investigate the effects of polysaccharide from Angelica and Astragalus (AAP) on carbon tetrachloride (CCl4) induced liver damage in mice. A total of 120 Kunming mice were randomly distributed among 6 groups comprising (i) the normal control mice, (ii) the CCl4 treatment group, (iii) the bifendate treatment group, (iv) the AAP treatment group, (v) the Angelica sinensis polysaccharide (ASP) treatment group, and (vi) the Astragalus membranaceus polysaccharide (AMP) treatment group. AAP, ASP and AMP were administered to mice treated with CCl4. The activities of alanine transaminase (ALT) and aspartate transaminase (AST) in the serum, and superoxide dismutase (SOD) and malondialdehyde (MDA) in the liver tissues were quantified, as well as the liver index. Hepatic histological changes were observed by staining liver sections with hematoxylin and eosin. Our results show that bifendate, AAP, ASP, and AMP significantly decreased the activities of MDA, AST, and ALT, and enhanced the activity of SOD in CCl4-treated mice. Bifendate, AAP, ASP, and AMP consistently ameliorated the liver injuries induced with CCl4. Notably, the hepatoprotective effect of AAP was stronger than that of bifendate, ASP, or AMP. In addition, AAP alleviated liver inflammation and decreased the liver indexes of mice induced with CCl4. These effects were at least partly due to the antioxidant properties of AAP in scavenging free radicals to ameliorate oxidative stress and to inhibit lipid peroxidation.

Polyphylla saponin I has antiviral activity against influenza A virus.

OBJECTIVE: In the present study, the antiviral effects of polyphylla saponin I isolated from Parispolyphylla on influenza A virus are investigated both in vitro and in vivo. METHODS: Column chromatography and reversed phase liquid chromatography separation technology were used to extract and purify polyphylla saponin I. The purity of polyphylla saponin I was assayed by high performance liquid chromatography. Methyl thiazolyl tetrazolium assay and analyses of cytopathic effects were performed to examine the antiviral activity of polyphylla saponin I upon MDCK cells infected with influenza A virus. Model mice were made by intranasal inoculation of influenza a virus. Mice infected with influenza A virus were orally administered polyphylla saponin I and oseltamivir twice a day for 5 days to study their antiviral efficacy in vivo. RESULTS: Polyphylla saponin I had no cytotoxicity on MDCK cells at the concentration of 50 µg/mL. Polyphylla saponin I (6.25, 12.5, 25 and 50 µg/mL) and oseltamivir (40 µg/mL) had remarkable inactivation effects on influenza A virus, prevention effects on influenza A virus adsorption on MDCK cells, and inhibitory effects on the reproduction of influenza A virus in MDCK cells. In addition, polyphylla saponin I (5 and 10 mg/kg), and oseltamivir (3 mg/kg) significantly reduced viral hemagglutination titer, improved the pathologic histology of lung tissues, and decreased the mortality of mice infected with influenza A virus. Polyphylla saponin I (5 and 10 mg/kg) prolonged the survival time of mice from 8.5±0.3 days to 13.2±0.5 days, with the prolonged life rates being 49.4% and 55.3%, respectively. CONCLUSION: Polyphylla saponin I has antiviral activity on influenza A virus both in vitro and in vivo.

Synthesis and biological activities of novel pleuromutilin derivatives with a substituted thiadiazole moiety as potent drug-resistant bacteria inhibitors.

A series of novel pleuromutilin derivatives possessing thiadiazole moieties were synthesized via acylation reactions under mild conditions. The in vitro antibacterial activities of the derivatives against methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis, Escherichia coli, and Streptococcus agalactiae were tested by the agar dilution method and Oxford cup assay. The majority of the tested compounds displayed moderate antibacterial activities. Importantly, the three compounds with amino or tertiary amine groups in their side chains, 11, 13b, and 15c, were the most active antibacterial agents. Docking experiments carried out on the peptidyl transferase center (PTC) of 23S rRNA proved that there is a reasonable direct correlation between the binding free energy (ΔGb, kcal/mol) and the antibacterial activity. Moreover, the pharmacokinetic profiles of 11 and 15c in rat were characterized by moderate clearance and oral bioavailability.

Antiviral activity of GuiQi polysaccharides against enterovirus 71 in vitro.

In this study, we have investigated the antiviral activity of GuiQi polysaccharides (GQP) upon enterovirus 71 (EV71) in vitro. An assay using methyl thiazolyl tetrazolium (MTT), and analyses of cytopathic effects (CPE) were used to examine the antiviral activity of GQP upon Vero cells infected with EV71. The results revealed that GQP at concentrations below 31.2 µg/mL exhibited significant antiviral effects upon EV71 when applied under three different experimental protocols. GQP was most strongly active in preventing the adsorption of EV71 to target cells and in this respect it was significantly more effective than ribavirin. In addition, it was clear that GQP could inhibit viral replication when added to cells 2 h after infection, but if added at the point of infection its effect was weak. GQP is considered to be less toxic than ribavirin, and may warrant further evaluation as a possible agent in the treatment of hand, foot and mouth disease (HFMD).

[Determination of microelements from different types of grass in the habitat of Przewalski's gazelle by sealed microwave digestion ICP-AES].

For the mixture forge from different types of grassland, trace elements including copper, manganese, iron, zinc and molybdenum were separately determined by ICP-AES using high pressure system-sealed microwave digestion in the habitat of the Przewalski's gazelle in Qinghai Hudong in summer (mid-June), autumn (mid-September) and winter (mid-December). The samples of mixture forage were digested with HNO3-H2O2 acids system. The detection limits of the method for the elements varied from 0.002 to 0.008 microg x g(-1), with relative standard deviations between 0.13% and 4.29%, and the spike recovery ratios for them were in the range from 94.0% to 101.30%. This method was simple, sensitive and precise compared with conventional method, which will provide scientific basis for the research on gazelles habitat condition.

Hypericum perforatum extract therapy for chickens experimentally infected with infectious bursal disease virus and its influence on immunity.

Hypericum perforatum extract (HPE) has been proved a drug effective to many viral diseases. The purpose of this paper was to investigate the therapeutic efficacy and immuno-enhancement of HPE for chickens which were already challenged with infectious bursal disease virus (IBDV BC-6/85). Chickens infected with IBDV were treated with HPE for 5 consecutive days, the observation of immune organ indexes and pathological changes index, determination of IFN-α and detection of IBDV with RT-PCR were employed to assess in vivo whether or not HPE had the certain therapeutic efficacy on infectious bursal disease (IBD), and if HPE was able to improve the immunologic function. The results showed that 1330 and 667.9 mg/kg body weight (BW) per day of HPE had significant therapeutic efficacy and improvement immunologic functions for chickens infected experimentally with IBDV.

Studies of a naturally occurring sulfur-induced copper deficiency in Przewalski's gazelles.

The Przewalski's gazelles in the Hudong area of the Qinghai Lake area in China were affected by an ailment characterized by pica, emaciation, dyskinesia, loss of appetite, and anemia. Concentrations of copper (Cu) in soil and forage from affected and unaffected areas were similar and within the normal range, but concentrations of sulfur (S) in soil and forage were significantly higher (P < 0.01) in affected than in unaffected areas. Concentrations of Cu in blood, hair, and liver from the affected Przewalski's gazelles were significantly lower (P < 0.01) than those in healthy animals. Affected Przewalski's gazelles showed a hypochromic microcytic anemia and a low level of ceruloplasmin. Oral administration of copper sulphate (CuSO(4)) prevented and cured the disease. We conclude that the disorder of Przewalski's gazelles was caused by secondary Cu deficiency, mainly due to high S content in forage.