Current Pharmaceutical Biotechnology - Volume 20, Issue 9, 2019

Allergic diseases are one of the most prevalent diseases at present, it is imperative to understanding the pathophysiology and treatment strategies for allergic diseases. In this process, the binding of IgE and FcεRI on effector cells plays a critical role in triggering allergic reactions. However, the species specificity of the interaction between IgE and FcεRI has not been clearly explained. This review described the characteristics and the interaction mechanism in the allergic reaction of IgE and FcεRI and summarized the species specificity between IgE and FcεRI.

Background: "Opuntia ficus-indica" (prickly pear) is the cactus member of the Cactaceae family as an important nutrient and food source. Objective: The purpose of this study was to characterize the phytochemical composition of hydroalcoholic extract of prickly pear seeds that cause therapeutic effects. Methods: Phytochemical screening based on simple tests and determination of secondary metabolites were performed by High-Performance Liquid with Diode-Array Detection (HPLC-DAD) analysis. For the pharmacological studies, the anti-inflammatory activity in rats was evaluated by carrageenaninduced inflammation, the description of the sedative activity was carried to the following behavioural tests, and the analgesic effect of the extract was assessed by the resistance induced by acetic acid, and the tail immersion test in mice. Results: The test drug at 500 mg/kg dose showed a significant increase in mean latency in the TAIL FLICK test, and a decrease in the average number of twisting movements in the KOSTER test, thus, a significant anti-inflammatory activity in the pattern of paw edema induced by carrageenan, and an important sedative effect on the central nervous system. Conclusion: These data suggest that the seeds of the cactus "Opuntia ficus-indica" could be a potential source of natural compound and reveal that the hydroethanolic extract of this species is a promising source, as well as a therapeutic agent for the research of new natural active ingredients.

Background: Daptomycin is a popular anti-MRSA antibiotic, especially for surgical wound infections. The side-effects of Daptomycin dosage through intravenous administration have prompted the experimental use of topical Daptomycin. Also, combinatorial drug therapy involving noble metal nanoparticles and conventional antibiotics have proved beneficial in the past. The synergistic oligodynamic effect of Daptomycin with nanoparticles for topical application was attempted for the first time in this work. Objectives: The present study was focused on topical gel formulation containing Daptomycin combined with mycogenic gold, silver and bimetallic gold and silver nanoparticles and evaluation of their synergistic antibacterial effect against an MRSA strain. Methods: An efficient approach for fungal growth was discussed wherein the biomass was cultivated under non-limiting conditions, followed by the addition of gold salt, silver salt and bimetallic (Gold and silver) solution. The metal salt reduction efficacy was evaluated using Cyclic Voltammetry. Formation of nanoparticles was observed by visual color changes and confirmed by UV-visible characteristic peaks. The mycosynthesized metallic and bimetallic nanoparticles were characterized by various advanced analytical methods. Further, Daptomycin was combined with nanoparticles in a topical gel formulation. The properties of the topical gels were evaluated and their antimicrobial activity was investigated against an MRSA strain associated with burn infections though disc diffusion method. Results: Formation of nanoparticles was observed by visual color changes and confirmed by UVvisible characteristic peaks. XRD spectra revealed the crystalline nature of nanoparticles whereas TEM confirmed the presence of spherical nanoparticles. The bio fabricated nanoparticles were characterized using ICP-MS, XRD and TEM. The UV-Visible spectrum of the gold, silver, bimetallic nanoparticles showed a characteristic peak at 550 nm, 450 nm, and 480 nm, respectively. ICP-MS of the residual salt concentration depicted more than 75% bioconversion of metal salt to metal nanoparticles. TEM showed the formation of uniform, spherical monometallic nanoparticles. XRD results were in sync with the dynamic light scattering experiments which determined that the gold, silver, bimetallic nanoparticles ranged between 10-20 nm, 5-30 nm, and 20-40 nm respectively and were crystalline in nature with the face centered cubic symmetry. Topical gels combining Daptomycin and nanoparticles were formulated and characterized. The in-vitro drug release studies indicated controlled release of antibiotic from bimetallic nanoparticles and Daptomycin combination in topical gel formulation. The MIC values reduced for the combinatorial drug and the average synergistic antimicrobial effect was 37% and the increase in efficacy of Daptomycin due to the synergistic effect with bimetallic nanoparticles was 43%. Conclusion: Topical gels were formulated using the biologically synthesized gold, silver and bimetallic gold-silver nanoparticles and modern-day antibiotic Daptomycin to combat burn infections. The topical gel formulations showed enhanced antimicrobial activity against methicillin-resistant Staphylococcus aureus at lower MIC values as compared to individual nanoparticle or antibiotic. The best results were obtained with bimetallic nanoparticles in topical gel formulation as it assisted in controlled drug release up to 94.6% and improved antimicrobial effect i.e. 43%.

Objective: This study aimed to observe the effects of dihydroartemisinin (DHA) on the proliferation, apoptosis, invasion, migration, and epithelial-mesenchymal transition (EMT) of the human gastric cancer cell line SGC7901 cultured in vitro. Methods: We applied varying concentrations of DHA to SGC7901 cells. Cell proliferation was measured using the cell counting kit-8 (CCK-8). Flow cytometry, Transwell invasion assay, and cell scratch assay were used to investigate the cells’ apoptosis, invasion, and migration. Western blot was used to assess the expression levels of EMT markers E-cadhein and Vimentin, protein kinases Akt and phosphorylated AKT (p-AKT), and the cell transcription factor Snail. Results: DHA can effectively inhibit the malignant proliferation of gastric cancer cells in a time- and dose-dependent manner. In this study, with longer incubation times and increased drug concentrations, the antiproliferation effect of DHA on SGC7901 cells increased gradually (P<0.05). In addition, with the increase of drug concentration, the expression levels of E-cadhein, an epithelial-mesenchymal transition marker, remarkably increased, whereas the protein expression levels of the mesenchymal markers Vimentin, Akt, p-Akt, and Snail significantly decreased (P<0.05). Conclusion: DHA can effectively inhibit the proliferation, invasion, and metastasis of the gastric cancer cell line SGC7901 and induce cancer cell apoptosis. DHA can also downregulate PI3K/AKT and Snail activities and inhibit the epithelial-mesenchymal transition of gastric cancer cells. The potential anticancer effects of DHA deserve further investigation.

Background: In the course of neoplastic diseases, a reduction in SEMA3F expression is observed, which translates into an increase in the proliferative and proangiogenic potential of cells forming the tumor and the surrounding microenvironment. Objective: The aim of this study was to determine the changes in SEMA3F level in endometrial cancer depending on its grade. Methods: The study material consisted of tissue samples: 15 without neoplastic changes (control group) and 45 with endometrial cancer (G1, 17; G2, 15; G3, 13; study group). SEMA3F expression was assessed using the immune-histochemical method. Results: The expression of SEMA3F was observed in the control group (Me = 159.38) and in the study group (G1, Me = 121.32; G2, Me = 0; G3, Me = 130.37). Differences between each grade and control and between individual grades were statistically significant. There were no significant correlations between SEMA3F expression and weight and Body Mass Index (BMI). The reduced SEMA3F expression in tumor tissue compared to healthy tissue indicates that this protein plays key roles in proliferation and angiogenesis. Conclusion: We found that depending on the severity of the disease, cancer adopts different survival strategies, where SEMA3F plays an important role. As a molecular marker, SEMA3F is not sensitive to weight and BMI.

Background: Recurrent pharyngotonsillitis due to Streptococcus pyogenes develops regardless of whether infecting strains are resistant or susceptible to first-line antimicrobials. Causation for recurrent infection is associated with the use of first-line antimicrobials that fail to penetrate deep tissue and host cell membranes, enabling intracellular S. pyogenes to survive throughout repeated rounds of antimicrobial therapy. Objective: To determine whether simvastatin, a therapeutic approved for use in the treatment of hypercholesterolemia, and ML141, a first-in-class small molecule inhibitor with specificity for human CDC42, limit host cell invasion by S. pyogenes. Methods: Assays to assess host cell invasion, bactericidal activity, host cell viability, actin depolymerization, and fibronectin binding were performed using the RAW 267.4 macrophage cell line and Human Umbilical Vein Endothelial Cells (HUVEC) infected with S. pyogenes (90-226) and treated with simvastatin, ML141, structural analogs of ML141, or vehicle control. Results: Simvastatin and ML141 decreased intracellular infection by S. pyogenes in a dose-dependent manner. Inhibition by simvastatin persisted following 1 h washout whereas inhibition by ML141 was reversed. During S. pyogenes infection, actin stress fibers depolymerized in vehicle control treated cells, yet remained intact in simvastatin and in ML141 treated cells. Consistent with the previous characterization of ML141, simvastatin decreased host cell binding to fibronectin. Structural analogs of ML141, designated as the RSM series, decreased intracellular infection through non-cytotoxic, nonbactericidal mechanisms. Conclusion: Our findings demonstrate the potential of repurposing simvastatin and of developing CDC42-targeted therapeutics for eradicating intracellular S. pyogenes infection to break the cycle of recurrent infection through a host-directed approach.

Background: The over use of current antibiotics and low discovery rate of the new ones are leading to rapid development of multidrug-resistant pathogens worldwide. Antimicrobial peptides have shown promising results against multidrug-resistant bacteria. Objective: To investigate the antimicrobial activity of a new ultrashort hexapeptide (OW). Methods: The OW hexapeptide was designed and tested against different strains of bacteria with different levels of sensitivity. Bacterial susceptibility assays were performed according to the guidelines of the Clinical and Laboratory Institute (CLSI). The synergistic studies were then conducted using the Checkerboard assay. This was followed by checking the hemolytic effect of the hexapeptide against human blood cells and Human Embryonic Kidney cell line (HEK293). Finally, the antibiofilm activities of the hexapeptide were studied using the Biofilm Calgary method. Results: Synergistic assays showed that OW has synergistic effects with antibiotics of different mechanisms of action. It showed an outstanding synergism with Rifampicin against methicillin resistant Staphylococcus aureus; ΣFIC value was 0.37, and the MIC value of Rifampicin was decreased by 85%. OW peptide also displayed an excellent synergism with Ampicillin against multidrug-resistant Pseudomonas aeruginosa, with ΣFIC value of less than 0.38 and a reduction of more than 96% in the MIC value of Ampicillin. Conclusion: This study introduced a new ultrashort peptide (OW) with promising antimicrobial potential in the management of drug-resistant infectious diseases as a single agent or in combination with commonly used antibiotics. Further studies are needed to investigate the exact mechanism of action of these peptides.

Background: To decipher EEG (Electroencephalography), intending to locate inter-ictal and ictal discharges for supporting the diagnoses of epilepsy and locating the seizure focus, is a critical task. The aim of this work was to find how the ensemble model distinguishes between two different sets of problems which are group 1: inter-ictal and ictal, group 2: controlled and inter-ictal using approximate entropy as a parameter. Methods: This work addresses the classification problem for two groups; Group 1: “inter-ictal vs. ictal” for which case 1(C-E), and case 2(D-E) are included and Group 2; “activity from controlled vs. inter-ictal activity” considering four cases which are case 3 (A-C), case 4(B-C), case 5 (A-D) and case 6(B-D) respectively. To divide the EEG into sub-bands, DWT (Discrete Wavelet Transform) was used and approximate Entropy was extracted out of all the five sub-bands of EEG for each case. Bagged SVM was used to classify the different groups considered. Results: The highest accuracy for Group 1 using Bagged SVM Ensemble model for case 1 was observed to be 96.83% with testing data; which was similar to 97% achieved by using training data. For case 2 (D-E) 93.92% accuracy with training and 84.83% with testing data were obtained. For Group 2, there was a large disparity between SVM and Bagged Ensemble model, where 76%, 81.66%, 72.835% and 71.16% for case 3, case 4, case 5 and case 6 were obtained. While for training data set, 92.87%, 91.74%, 92% and 92.64% accuracy was attained, respectively. The results obtained by SVM for Group 2 showed a huge difference from the highest accuracy achieved by bagged SVM for both the training and the test data. Conclusion: Bagged Ensemble model outperformed SVM model for every case with a huge difference with both training as well as test dataset for Group 2 and marginally better for Group 1.

Background: The development of antibiotic resistance amongst bacterial pathogens and a population explosion, e.g. in countries such as Indonesia, are two issues the world is facing today. These issues have stimulated interest in the development of new antimicrobial therapeutic agents and contraceptive strategies, such as novel spermicides. Bacteriocins, which are bacterially-derived antimicrobial peptides, may fulfill some of the criteria for these new agents. Methods: Weissella confusa MBF8-1, originally isolated from a homemade soy product, exhibits antibacterial activity that was subsequently found to be plasmid-encoded, presumably by three peptides Bac1, Bac2 and Bac3. In the present study, we tested cell-free MBF8-1 bacteriocin preparations and chemically-synthesized versions of Bac1, Bac2 and Bac3 peptides for (i) its antibacterial activity against the indicator bacterium Leuconostoc mesenteroides and (ii) its ability to affect the motility of spermatozoa. Nisin, a known lantibiotic bacteriocin, was used as the control. Results: Here, we demonstrate that synthetic Bac1, in combination with synthetic Bac2, was sufficient to inhibit the growth of L. mesenteroides and affect sperm motility. However, the presence of all three synthetic peptides, s-Bac1, s-Bac2 and s-Bac3, was required for full potency. Conclusion: In summary, the bacteriocin-like peptides of W. confusa MBF8-1 have the potential to be developed as a narrow-spectrum antimicrobial agent and a novel spermicidal agent.