Specific Inhibitory Activity Research Articles

Induction of autophagy increases the proteolytic activity of reservosomes during Trypanosoma cruzi metacyclogenesis

ABSTRACT Cruzipain, the major cysteine protease of the pathogenic protozoa Trypanosoma cruzi, is an important virulence factor that plays a key role in the parasite nutrition, differentiation and host cell infection. Cruzipain is synthesized as a zymogen, matured, and delivered to reservosomes. These organelles that store proteins and lipids ingested by endocytosis undergo a dramatic decrease in number during the metacyclogenesis of T. cruzi. Autophagy is a process that digests the own cell components to supply energy under starvation or different stress situations. This pathway is important during cell growth, differentiation and death. Previously, we showed that the autophagy pathway of T. cruzi is induced during metacyclogenesis. This work aimed to evaluate the participation of macroautophagy/autophagy in the distribution and function of reservosomes and cruzipain during this process. We found that parasite starvation promotes the cruzipain delivery to reservosomes. Enhanced autophagy increases acidity and hydrolytic activity in these compartments resulting in cruzipain enzymatic activation and self- processing. Inhibition of autophagy similarly impairs cruzipain traffic and activity than protease inhibitors, whereas mutant parasites that exhibit increased basal autophagy, also display increased cruzipain processing under control conditions. Further experiments showed that autophagy induced cruzipain activation and self-processing promote T. cruzi differentiation and host cell infection. These findings highlight the key role of T. cruzi autophagy in these processes and reveal a potential new target for Chagas disease therapy. Abbreviations: Baf: bafilomycin A1; CTE: C-terminal extension; Cz: cruzipain; IIF: indirect immunofluorescence; K777: vinyl sulfone with specific Cz inhibitory activity; Prot Inh: broad-spectrum protease inhibitor; Spa1: spautin-1; Wort: wortmannin

In vitro studies of potent aldose reductase inhibitors: Synthesis, characterization, biological evaluation and docking analysis of rhodanine-3-hippuric acid derivatives.

Inhibitors of aldose reductase are rate-limiting enzymes and could play a key role to prevent the complications of diabetes. In our attempt to develop novel inhibitors of aldose reductase, the derivatives of rhodanine-3-hippuric acid-pyrazole hybrid were synthesized and characterised by spectral data. The biological studies reveal that all the compounds show an excellent activity against ALR2 with IC50 values ranging from 0.04 to 1.36µM. Among these the synthesised compounds 6a-m, 6g and 6e showed specific inhibitory activity with IC50 values of 0.04 and 0.06µM respectively against ALR2 and found to be more potent than epalrestat (IC50=0.87μM), the only aldose reductase inhibitor currently used in the therapy. Molecular docking analysis using the AR-NADP+ complex as a receptor was performed with all the synthesized compounds. All the compounds exhibit a well-defined binding mode within the AR active site, similarly to previous described AR inhibitors, with the anion head group bound to the catalytic center, blocking thus its activity. By forming hydrogen bonds with Tyr48 and His110 of the protein from ALR2 (PDB ID: 2FZD), the compounds 6g and 6e interrupt the proton donation mechanism, which is necessary for the catalytic activity of ALR2.

Pharmacological Properties of JTE-952, an Orally Available and Selective Colony Stimulating Factor 1 Receptor Kinase Inhibitor.

Colony stimulating factor 1 (CSF1) receptor (CSF1R) is a receptor protein-tyrosine kinase specifically expressed in monocyte-lineage cells, such as monocytes and macrophages. In this study, we characterized the pharmacological properties of an azetidine compound, JTE-952 ((2S)-3-{[2-({3-[4-(4-cyclopropylbenzyloxy)-3-methoxyphenyl]azetidine-1-yl}carbonyl)pyridin-4-yl]methoxy}propane-1,2-diol), which is a novel CSF1R tyrosine kinase inhibitor. JTE-952 potently inhibited human CSF1R kinase activity, with a half maximal inhibitory concentration of 11.1 nmol/L, and inhibited the phosphorylation of CSF1R in human macrophages and the CSF1-induced proliferation of human macrophages. It also inhibited human tropomyosin-related kinase A activity, but only at concentrations 200-fold higher than that required to inhibit the activity of CSF1R in inducing the proliferation of human macrophages. JTE-952 displayed no marked inhibitory activity against other kinases. JTE-952 potently inhibited lipopolysaccharide-induced proinflammatory cytokine production by human macrophages and in whole blood. JTE-952 (≥3 mg/kg given orally) also significantly attenuated the CSF1-induced priming of lipopolysaccharide-induced tumor necrosis factor-alpha production in mice and arthritis severity in a mouse model of collagen-induced arthritis. Taken together, these results indicate that JTE-952 is an orally available compound with potent and specific inhibitory activity against CSF1R, both in vitro and in vivo. JTE-952 is a potentially clinically useful agent for various human inflammatory diseases, including rheumatoid arthritis.

Medicinal chemistry strategies to discover P-glycoprotein inhibitors: An update.

The presence of multidrug resistance (MDR) in malignant tumors is one of the primary causes of treatment failure in cancer chemotherapy. The overexpression of the ATP binding cassette (ABC) transporter, P-glycoprotein (P-gp), which significantly increases the efflux of certain anticancer drugs from tumor cells, produces MDR. Therefore, inhibition of P-gp may represent a viable therapeutic strategy to overcome cancer MDR. Over the past 4 decades, many compounds with P-gp inhibitory efficacy (referred to as first- and second-generation P-gp inhibitors) have been identified or synthesized. However, these compounds were not successful in clinical trials due to a lack of efficacy and/or untoward toxicity. Subsequently, third- and fourth-generation P-gp inhibitors were developed but dedicated clinical trials did not indicate a significant therapeutic effect. In recent years, an extraordinary array of highly potent, selective, and low-toxicity P-gp inhibitors have been reported. Herein, we provide a comprehensive review of the synthetic and natural products that have specific inhibitory activity on P-gp drug efflux as well as promising chemosensitizing efficacy in MDR cancer cells. The present review focuses primarily on the structural features, design strategies, and structure-activity relationships (SAR) of these compounds.

Antihypertensive Effects of Virgin Olive Oil (Unfiltered) Low Molecular Weight Peptides with ACE Inhibitory Activity in Spontaneously Hypertensive Rats

The low molecular weight peptide composition of virgin olive oil (VOO) is mostly unknown. We hypothesised that unfiltered VOO could possess low molecular weight peptides with antihypertensive activity. We produced unfiltered VOO and obtained a water-soluble peptide extract from it. The peptides were separated by size-exclusion using fast protein liquid chromatography, and the low molecular weight fraction was analysed by nanoscale liquid chromatography-Orbitrap coupled with tandem mass spectrometry and de novo sequencing. We selected 23 peptide sequences containing between 6 and 9 amino acids and molecular masses ranging 698–1017 Da. Those peptides were chemically synthesised and their angiotensin-converting enzyme (ACE) inhibitory activity was studied in vitro. Seven peptides showed a strong activity, with half maximal inhibitory concentration (IC50) <10 µm. The antihypertensive effects of the four most active synthesised ACE inhibitor peptides were studied in spontaneously hypertensive rats (SHR). Acute oral administration of synthetic peptides RDGGYCC and CCGNAVPQ showed antihypertensive activity in SHR. We conclude that unfiltered VOO naturally contains low molecular weight peptides with specific ACE inhibitory activity and antihypertensive effects in SHR.

Benzo[b]tellurophenes as a Potential Histone H3 Lysine 9 Demethylase (KDM4) Inhibitor.

Gene expression and tumor growth can be regulated by methylation levels of lysine residues on histones, which are controlled by histone lysine demethylases (KDMs). Series of benzo[b]tellurophene and benzo[b]selenophene compounds were designed and synthesized and they were evaluated for histone H3 lysine 9 demethylase (KDM4) inhibitory activity. Among the carbamates, alcohol and aromatic derivatives, tert-butyl benzo[b]tellurophen-2-ylmethylcarbamate (compound 1c) revealed KDM4 specific inhibitory activity in cervical cancer HeLa cells, whereas the corresponding selenium or oxygen substitute compounds did not display any inhibitory activity toward KDM4. Compound 1c also induced cell death in cervical and colon cancer but not in normal cells. Thus, compound 1c, a novel inhibitor of KDM4, constitutes a potential therapeutic and research tool against cancer.

Abstract 2954: Mithramycin analogues disrupt ETS transcription factor DNA binding

Abstract Introduction: Ewing sarcoma, prostate cancer, and leukemia are a few examples where ETS transcription factors drive tumorigenesis. The transcription factors EWS-FLI1 and EWS-ERG are common translocations in Ewing sarcoma and bind DNA at GGAA repeats leading to expression of genes that drive tumor growth. Pharmacologic inhibition of EWS-FLI1 with mithramycin (MTM) was shown to inhibit expression of downstream genes and tumor growth in mice. But despite this specific inhibitory activity, MTM has a narrow therapeutic window with hematologic and hepatic toxicity attributed to displacement of the ubiquitously acting Sp1 transcription factor. Thus, a synthetic effort was initiated to develop MTM analogues with reduced toxicity and increased specificity for ETS binding sites. Structural studies informed the design of MTM analogues that may stabilize transcriptional complexes leading to the disruption of transcriptional activity and DNA damage. In vitro cytotoxicity assays demonstrated that MTM analogues have significantly higher cytotoxicity in EWS-ETS expressing cell lines. Here we present mechanistic evidence for the differences in biochemical activity among MTM and its novel analogues. Methods: Qualitative interactions between drug-DNA-protein were assessed and optimized by electrophoretic mobility shift assays (EMSA). Time-resolved fluorescence energy transfer (TR-FRET) assays were used to quantitatively determine ERG displacement from DNA in the presence of MTM and analogues. Expression of proteins indicating DNA damage (c-PARP, γ-H2AX) and phosphorylation at the C-terminal domain (CTD) of RNAPII was determined by western blot following drug treatments in ETS and non ETS expressing cell lines. Results: Using TR-FRET, we observed that MTM displaced DNA bound ERG more potently and in a concentration dependent manner as compared to MTM analogues. As compared to MTM, treatment with MTM analogues resulted in higher expression of DNA damage markers, γ-H2AX and c-PARP, specifically in cell lines containing EWS-ETS translocations in a concentration dependent manner. Conclusion: These studies provide insights regarding differences among MTM and analogues in DNA binding and interactions with DNA associated proteins in the presence and absence of EWS-ETS expression. Our results suggest that MTM analogues may bind and stabilize transcriptional complexes. These differences will provide the basis for structure activity relationships and for the development of analogues with decreased in vivo toxicity. Future work will incorporate co-immunoprecipitation studies to determine if physical protein interactions are being disrupted by MTM and analogues and cellular thermal shift assays to directly probe drug interactions with EWS-ETS proteins and with RNAPII. Note: This abstract was not presented at the meeting. Citation Format: Reiya C. Hayden, Caixia Hou, Prithiba Mitra, Abhisek Mandal, Jurgen Rohr, Jon Thorson, Oleg Tsodikov, Markos Leggas. Mithramycin analogues disrupt ETS transcription factor DNA binding [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2954.

Oceans as a Source of Immunotherapy.

Marine flora is taxonomically diverse, biologically active, and chemically unique. It is an excellent resource, which offers great opportunities for the discovery of new biopharmaceuticals such as immunomodulators and drugs targeting cancerous, inflammatory, microbial, and fungal diseases. The ability of some marine molecules to mediate specific inhibitory activities has been demonstrated in a range of cellular processes, including apoptosis, angiogenesis, and cell migration and adhesion. Immunomodulators have been shown to have significant therapeutic effects on immune-mediated diseases, but the search for safe and effective immunotherapies for other diseases such as sinusitis, atopic dermatitis, rheumatoid arthritis, asthma and allergies is ongoing. This review focuses on the marine-originated bioactive molecules with immunomodulatory potential, with a particular focus on the molecular mechanisms of specific agents with respect to their targets. It also addresses the commercial utilization of these compounds for possible drug improvement using metabolic engineering and genomics.

Phytochemical composition and biological activity of Armenian Muscari (Muscari armeniacum Leichtlin)

Введение. В настояшей статье рассматривается состав биологически активных соединений в надземных органах и луковицах мускари армянского (Muscari armeniacum Leichtlin) семейства Спаржевые (Asparagaceae Juss) и возможные фармакотерапевтические эффекты препаратов на его основе.

Novel Isoquinolinamine and Isoindoloquinazolinone Compounds Exhibit Antiproliferative Activity in Acute Lymphoblastic Leukemia Cells.

Nitrogen-containing heterocycles such as quinoline, quinazolinones and indole are scaffolds of natural products and have broad biological effects. During the last years those structures have been intensively synthesized and modified to yield new synthetic molecules that can specifically inhibit the activity of dysregulated protein kinases in cancer cells. Herein, a series of newly synthesized isoquinolinamine (FX-1 to 8) and isoindoloquinazolinone (FX-9, FX-42, FX-43) compounds were evaluated in regards to their anti-leukemic potential on human B- and T-acute lymphoblastic leukemia (ALL) cells. Several biological effects were observed. B-ALL cells (SEM, RS4;11) were more sensitive against isoquinolinamine compounds than T-ALL cells (Jurkat, CEM). In SEM cells, metabolic activity decreased with 10 μM up to 26.7% (FX-3), 25.2% (FX-7) and 14.5% (FX-8). The 3-(p-Tolyl) isoquinolin-1-amine FX-9 was the most effective agent against B- and T-ALL cells with IC50 values ranging from 0.54 to 1.94 μM. None of the tested compounds displayed hemolysis on erythrocytes or cytotoxicity against healthy leukocytes. Anti-proliferative effect of FX-9 was associated with changes in cell morphology and apoptosis induction. Further, influence of FX-9 on PI3K/AKT, MAPK and JAK/STAT signaling was detected but was heterogeneous. Functional inhibition testing of 58 kinases revealed no specific inhibitory activity among cancer-related kinases. In conclusion, FX-9 displays significant antileukemic activity in B- and T-ALL cells and should be further evaluated in regards to the mechanisms of action. Further compounds of the current series might serve as templates for the design of new compounds and as basic structures for modification approaches.

Mithramycin analogues disrupt ETS transcription factor DNA binding

IntroductionEwing sarcoma, prostate cancer, and leukemia are a few examples where ETS transcription factors drive tumorigenesis. The transcription factors EWS‐FLI1 and EWS‐ERG are common translocations in Ewing sarcoma and bind DNA at GGAA repeats leading to expression of genes that drive tumor growth. Pharmacologic inhibition of EWS‐FLI1 with mithramycin (MTM) was shown to inhibit expression of downstream genes and tumor growth in mice. But despite this specific inhibitory activity, MTM has a narrow therapeutic window with hematologic and hepatic toxicity attributed to displacement of the ubiquitously acting Sp1 transcription factor. Thus, a synthetic effort was initiated to develop MTM analogues with reduced toxicity and increased specificity for ETS binding sites. Structural studies informed the design of MTM analogues that may stabilize transcriptional complexes leading to the disruption of transcriptional activity and DNA damage. In vitro cytotoxicity assays demonstrated that MTM analogues have significantly higher cytotoxicity in EWS‐ETS expressing cell lines. Here we present mechanistic evidence for the differences in biochemical activity among MTM and its novel analogues.MethodsQualitative interactions between drug‐DNA‐protein were assessed and optimized by electrophoretic mobility shift assays (EMSA). Time‐resolved fluorescence energy transfer (TR‐FRET) assays were used to quantitatively determine ERG displacement from DNA in the presence of MTM and analogues. Expression of proteins indicating DNA damage (c‐PARP, γ‐H2AX) and phosphorylation at the C‐terminal domain (CTD) of RNAPII was determined by western blot following drug treatments in ETS and non ETS expressing cell lines.ResultsUsing TR‐FRET, we observed that MTM displaced DNA bound ERG more potently and in a concentration dependent manner as compared to MTM analogues. As compared to MTM, treatment with MTM analogues resulted in higher expression of DNA damage markers, γ‐H2AX and c‐PARP, specifically in cell lines containing EWS‐ETS translocations in a concentration dependent manner.ConclusionThese studies provide insights regarding differences among MTM and analogues in DNA binding and interactions with DNA associated proteins in the presence and absence of EWS‐ETS expression. Our results suggest that MTM analogues may bind and stabilize transcriptional complexes. These differences will provide the basis for structure activity relationships and for the development of analogues with decreased in vivo toxicity. Future work will incorporate co‐immunoprecipitation studies to determine if physical protein interactions are being disrupted by MTM and analogues and cellular thermal shift assays to directly probe drug interactions with EWS‐ETS proteins and with RNAPII.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

MUSCARI ARMENIACUM LEICHTLIN (GRAPE HYACINTH): PHYTOCHEMISTRY AND BIOLOGICAL ACTIVITIES REVIEW

This review focuses on the Muscari armeniacum Leichtlin (Asparagaceae Juss) biologically active substances composition presented in the Aireal and underground parts and finding their possible therapeutic effects. The systematic review is dedicated to the composition of biologically active substances, including recent advances in the biological activity investigation, phytochemical studies, and biotechnology methods of plant material producing. Various electronic search engines such as Google, Google Scholar, scientific literature, publishing sites, and electronic databases such as PubMed, Wiley, Springer, and Science Direct had been searched and data obtained. Other online academic libraries such as E-library and specific ethnopharmacological literature had been searched systematically for more exhaustive information on the crude herbal drug. The chemical composition of M. armeniacum biologically active substances is established; it contains anthocyanins (delphinidin and cyanidin derivatives), homoisoflavonoids, polyhydroxylated pyrrolizidine alkaloids (hyacinthacines A1, A2, A3, and B3), oligoglycosides (Muscarosides), and ribosome-inactivating proteins (musarmins). Recent physicochemical analytical procedures for components determination and hyacinthacines synthesis pathways are mentioned. Moreover, future prospects and trends in the research of this plant have been proposed. We have reviewed researches conducted on M. armeniacum especially in areas of its use in medicine, phytochemicals, biological activity, and developed analytical methods. M. armeniacum possesses antioxidant, antimutagenic activity, and specific glycosidase inhibitory activity; M. armeniacum can be used for the production of potential anticancer, antiviral, antidiabetic, and anti-obesity drugs. It should be noted that more pharmacognostic, pharmacological studies are needed for giving further information on the clinical practice and standardization procedures for the crude herbal drug.

MUSCARI ARMENIACUM LEICHTLIN (GRAPE HYACINTH): PHYTOCHEMISTRY AND BIOLOGICAL ACTIVITIES REVIEW

This review focuses on the Muscari armeniacum Leichtlin (Asparagaceae Juss) biologically active substances composition presented in the Aireal and underground parts and finding their possible therapeutic effects. The systematic review is dedicated to the composition of biologically active substances, including recent advances in the biological activity investigation, phytochemical studies, and biotechnology methods of plant material producing. Various electronic search engines such as Google, Google Scholar, scientific literature, publishing sites, and electronic databases such as PubMed, Wiley, Springer, and Science Direct had been searched and data obtained. Other online academic libraries such as E-library and specific ethnopharmacological literature had been searched systematically for more exhaustive information on the crude herbal drug. The chemical composition of M. armeniacum biologically active substances is established; it contains anthocyanins (delphinidin and cyanidin derivatives), homoisoflavonoids, polyhydroxylated pyrrolizidine alkaloids (hyacinthacines A1, A2, A3, and B3), oligoglycosides (Muscarosides), and ribosome-inactivating proteins (musarmins). Recent physicochemical analytical procedures for components determination and hyacinthacines synthesis pathways are mentioned. Moreover, future prospects and trends in the research of this plant have been proposed. We have reviewed researches conducted on M. armeniacum especially in areas of its use in medicine, phytochemicals, biological activity, and developed analytical methods. M. armeniacum possesses antioxidant, antimutagenic activity, and specific glycosidase inhibitory activity; M. armeniacum can be used for the production of potential anticancer, antiviral, antidiabetic, and anti-obesity drugs. It should be noted that more pharmacognostic, pharmacological studies are needed for giving further information on the clinical practice and standardization procedures for the crude herbal drug.

A Case-Control Study to Compare the Survival Benefits of Patients Who Suffer from Peripheral T-Cell Lymphoma (PTCL) Treated with Chidamide, a Histone Deacetylase Inhibitor, in China with a Historical Matched Cohort of Patients Treated with Conventional Therapy in Taiwan: Survival Advantage Is Demonstrated

Background Chidamide is a histone acetylase (HDAC) inhibitor with significant and specific inhibitory activities against HDAC subtypes 1, 2, 3, and 10. Although it is already approved for treating peripheral T-cell lymphoma (PTCL) with a phase II clinical trial in several countries, the evidences comparing its efficacy with conventional chemotherapy in PTCL is still very limited. This retrospective observational study compared the survival benefits of 65 patients with relapsed or refractory PTCL treated on a phase II pivotal clinical trial (CHIPEL) of Chidamide in China with 65 matched historical control patients treated with standard conventional therapy in Taiwan. The historical control patients should have been diagnosed with PTCL within 10 years (2007-2016). Each Chidamide-treated patient was matched with one historical control case in a 1:1 ratio. Data of historical control cohort was retrieved from trial sites in Taiwan.Methods The historical control patients were retrieved from lymphoma databases of three large medical centers in Taiwan, and pairs were matched to Chidamide-treated patients in accordance with a hierarchical matching manner in a group sequence, including subtype of PTCL, age group, gender, treatment with chemotherapy, radiotherapy or stem-cell transplantation and number of lines of therapy. Only patients, (1) who have received first-line therapy (CHOP, CHOP-like chemotherapy, stem cell transplantation, etc.) however relapsed or refractory after treatment, and (2) further received second-line therapy, were eligible for recruitment into this observational study.Results This study matched 42 out of the 65 eligible subjects treated with chidamide in the CHIPEL study to subjects treated for PTCL at three large medical centers in Taiwan. Subjects from both cohorts had relapsed or refractory PTCL, and their clinical parameters are listed on Table 1. The difference in overall survival (OS) demonstrated between the 2 cohorts is statistically significant and more importantly clinically significant. The most conservative tested statistical model gave a hazard ratio of 0.548 for death of CHIPEL subjects to Historical Control subjects. In addition, median overall survival after start of chidamide treatment in CHIPEL subjects was over five times as long as that of the matched Historical Control subjects. The median duration of overall survival was 567.5 days [122.0 to 1177.0 days] in the CHIPEL subjects vs. 102.0 days [37.0 to 188.0 days] in Historical Control subjects. (Log-rank P=0.0085, Stratified Log-rank P=0.0077) (as in Figure 1).Conclusions The results of this study provide evidence that overall survival is longer in refractory or relapsed PTCL patients treated with chidamide than those treated with conventional therapies. Based on the strong results in PTCL patients treated with chidamide in recent studies and the supportive evidence provided by this study chidamide can be seen as a promising drug for PTCL patients in Taiwan. DisclosuresKo:GNT Biotech & Medicals Crop.: Research Funding; Roche: Research Funding; Abbevie: Research Funding; Mumdipharma Taiwan: Consultancy. Yeh:GNT Biotech & Medicals Crop.: Research Funding. Kao:GNT Biotech & Medicals Crop.: Research Funding. Yu:GNT Biotech & Medicals Crop.: Research Funding. Ou:GNT Biotech & Medicals Crop.: Research Funding. Chang:Novarits: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Takeda: Consultancy; Celgene: Consultancy; Janssen: Consultancy, Speakers Bureau; AbbVie: Consultancy; BMS: Consultancy, Speakers Bureau.

Production of potent antidiabetic compounds from shrimp head powder via Paenibacillus conversion

Abstract Natural α-glucosidase inhibitors (aGIs) are of great interest as an efficacious and safe therapy for type 2 diabetes, which is an ongoing global health issue. The aim of this study is to utilize shrimp head powder (SHP), an abundant and low-cost material, for the biosynthesis, isolation, and identification of active antidiabetic compounds. SHP was efficiently converted to aGIs via Paenibacillus sp. TKU042 fermentation. Fermented SHP (fSHP) by this strain possesses high pH stability, and stronger yeast α-glucosidase inhibitory activity (92%) than that of acarbose (60%). aGI productivity increased more than 2-fold after optimization (from 225 U/mL to 560 U/mL). Further bioactivity-guided isolation of two major active compounds were identified as nicotinic acid and adenine. Notably, these inhibitors were non-sugar-based moiety aGIs, which is newly isolated and identified from fSHP in this study. In the tests of specific enzyme inhibitory activity, adenine showed highly specific inhibition against yeast α-glucosidase (IC50 = 22 μg/mL); nicotinic acid demonstrated good effect on rat α-glucosidase (IC50 = 70 μg/mL); while acarbose possessed efficient effect on bacteria, rice, and rat α-glucosidases (IC50 = 0.03–108 μg/mL). The current results suggest that it is cost-effective to produce potent aGIs from SHP via Paenibacillus conversion, and these active constituents may be useful in type 2 diabetes management.

From Marine Origin to Therapeutics: The Antitumor Potential of Marine Algae-Derived Compounds.

Marine environment has demonstrated to be an interesting source of compounds with uncommon and unique chemical features on which the molecular modeling and chemical synthesis of new drugs can be based with greater efficacy and specificity for the therapeutics. Cancer is a growing public health threat, and despite the advances in biomedical research and technology, there is an urgent need for the development of new anticancer drugs. In this field, it is estimated that more than 60% of commercially available anticancer drugs are natural biomimetic inspired. Among the marine organisms, algae have revealed to be one of the major sources of new compounds of marine origin, including those exhibiting antitumor and cytotoxic potential. These compounds demonstrated ability to mediate specific inhibitory activities on a number of key cellular processes, including apoptosis pathways, angiogenesis, migration and invasion, in both in vitro and in vivo models, revealing their potential to be used as anticancer drugs. This review will focus on the bioactive molecules from algae with antitumor potential, from their origin to their potential uses, with special emphasis to the alga Sphaerococcus coronopifolius as a producer of cytotoxic compounds.

Characterization of Capsicum annuum L. leaf and root antimicrobial peptides: antimicrobial activity against phytopathogenic microorganisms

This study aimed to detect and characterize antimicrobial proteins, especially antimicrobial peptides (AMPs) from leaves and roots of Capsicum annuum and to evaluate their inhibitory activities against different phytopathogenic fungi and the bacterium Xanthomonas euvesicatoria. Two methodologies were used for the extraction of peptides from leaves and roots of C. annuum: acid and ethanolic extraction. Extracts were subjected to reversed-phase chromatography on HPLC. The extraction and purification procedures were analysed by uni- and bi-dimensional electrophoresis in tricine gels. Our results show that alcoholic and acid extracts from both tissues can inhibit the growth of the phytopathogenics fungi C. lindemuthianum and C. gloeosporioides. The acid extracts from both tissues are active against X. euvesicatoria and only leaf extracts displayed specific inhibitory activity towards trypsin and α-amylase activity. The data compiled here aim to contribute to establish the multiplicity of potential uses of plant AMPs for the control of pests and pathogens of agricultural relevance.

Novel cyclo-peptides inhibit Ebola pseudotyped virus entry by targeting primed GP protein

Ebola virus (EBOV) causes fatal hemorrhagic fever with high death rates in human. Currently, there are no available clinically-approved prophylactic or therapeutic treatments. The recently solved crystal structure of cleavage-primed EBOV glycoprotein (GPcl) in complex with the C domain of endosomal protein Niemann-Pick C1 (NPC1) provides a new target for the development of EBOV entry inhibitors. In this work, a computational approach using docking and molecular dynamic simulations is carried out for the rational design of peptide inhibitors. A novel cyclo-peptide (Pep-3.3) was identified to target at the late stage of EBOV entry and exhibit specific inhibitory activity against EBOV-GP pseudotyped viruses, with 50% inhibitory concentration (IC50) of 5.1 μM. In vitro binding assay and molecular simulations revealed that Pep-3.3 binds to GPcl with a KD value of 69.7 μM, through interacting with predicted residues in the hydrophobic binding pocket of GPcl. Mutation of predicted residues T83 caused resistance to Pep-3.3 inhibition in viral infectivity, providing preliminary support for the model of the peptide binding to GPcl. This study demonstrates the feasibility of inhibiting EBOV entry by targeting GPcl with peptides.

A dual-function epidermal growth factor receptor pathway substrate 8 (Eps8)-derived peptide exhibits a potent cytotoxic T lymphocyte-activating effect and a specific inhibitory activity

The identification and characterization of tumor-associated antigens (TAAs) that generate specific cytotoxic T lymphocytes (CTLs) are vital to the development of cancer immunotherapy. The epidermal growth factor receptor (EGFR) pathway substrate 8 gene (Eps8) is involved in regulating cancer progression and might be an ideal antigen. In this study, we searched for novel human leukocyte antigen (HLA)-A*2402-restricted epitopes derived from the Eps8 protein via the HLA-binding prediction algorithm. Among four candidates, peptides 327 (EFLDCFQKF), 534 (KYAKSKYDF) and 755 (LFSLNKDEL) induced peptide-specific CTLs to secrete higher levels of interferon-gamma (IFN-γ) and showed enhanced cytotoxic activity against malignant cancer cells. Our results demonstrated that peptide-specific CTLs showed effective antitumor responses, including upregulation of interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-α), granzyme B and perforin. Treatment with peptide-sensitized peripheral blood mononuclear cells (PBMCs) significantly reduced the tumor growth in vivo compared with the non-peptide-sensitized PBMC treatment. Importantly, our results indicated that peptide 327 may interfere with EGFR signaling by mechanistically disrupting Eps8/EGFR complex formation. We extended this observation that peptide 327 also suppressed the viability of cancer cells, blocked EGFR signal pathway and reduced the expression of downstream targets. Notably, conjugation of peptide 327 to the TAT sequence (TAT-327) resulted in potent antitumor activity and selective insertion into cancer cell membranes, where it adopted a punctate distribution. Furthermore, peptide 327 and TAT-327 displayed anticancer properties in xenograft models. Our results indicated that 327, 534 and 755 were novel HLA-A*2402-restricted epitopes from Eps8. By inhibiting the Eps8/EGFR interaction, peptide 327 and TAT-327 may serve as novel peptide inhibitors, which could provide an innovative approach for treating various cancers.

Characterization of a Kazal-type serine protease inhibitor from black rockfish Sebastes schlegelii and its possible role in hepatic immune response

Kazal-type serine protease inhibitors (KSPIs) play important roles in the regulation of endogenous proteases, cell development, blood coagulation, and immune response. In this study, we identified and characterized a KSPI homologue (SsKSPI) in black rockfish, Sebastes schlegelii. The full-length cDNA sequence of SsKSPI was 532 base pairs (bp), including an open reading frame (ORF) of 330 bp, which encodes a polypeptide of 110 amino acids with a signal peptide of 21 amino acids. The greatest value for identity (42.9%) and similarity (50.9%) was observed with Channa striata KSPI. We purified the recombinant protein of SsKSPI and performed protease inhibitory assays using three common serine proteases. The recombinant SsKSPI exhibited specific inhibitory activity against subtilisin A in a dose-dependent manner. Tissue distribution of SsKSPI mRNA has been examined amongst 10 important tissues in healthy rockfish and the liver was found to be the predominant expression organ of SsKSPI. The modulation of SsKSPI expression under immune challenges was also investigated in the liver. The SsKSPI mRNA expression was significantly up-regulated in response to both bacterial (Streptococcus iniae and lipopolysaccharide) and viral (polyinosinic:polycytidylic acid) challenges. Overall, we propose that SsKSPI is potentially involved in the hepatic immune response against bacterial and viral infections in black rockfish.