Immunization of mice with chimeric protein-loaded aluminum hydroxide and selenium nanoparticles induces reduction of Brucella melitensis infection in mice.

Purpose: Due to the many problems with commercially available vaccines, the production of effective vaccines against brucellosis is a necessity. The aim of this study was to evaluate the immune responses caused by the chimeric protein consisting of trigger factor, Bp26, and Omp31 (TBO) along with aluminum hydroxide (AH/TBO) and selenium (Se/TBO) nanoparticles (NPs) as adjuvants in mouse model. Materials and Methods: Recombinant antigen expression was induced in Escherichia coli BL21 (DE3) bacteria using IPTG (isopropyl-d-1-thiogalactopyranoside). Purification and characterization of recombinant protein was conducted through NiFe3O4 NPs, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and Western blot. NP characteristics, including morphology and particle size, were measured in vitro. The recombinant TBO was loaded on to AH and Se NPs and were administered subcutaneously. After mice immunization, measurement of antibody titter and protection assay was performed. Results: The average sizes of AH and Se NPs were about 60 nm and 150 nm, respectively. The enzyme-linked immunosorbent assay results showed that the serum of mice immunized by subcutaneous injection with both nanovaccines produced significant immunoglobulin G (IgG) responses against the chimeric antigen. The results of TBO-specific IgG isotype (IgG2a/IgG1) analysis showed that both AH and Se NPs induced a type to T-helper immune response. In addition, the results of the challenge with the pathogenic strain of Brucella melitensis 16M showed that vaccinated mice with AH/TBO NPs indicated a higher reduction of bacterial culture than immunized mice with Se/TBO NPs and TBO alone. Conclusion: The results showed that AH NPs carrying chimeric antigen can be a promising vaccine candidate against brucellosis by producing protective immunity.

In Silico Vaccine Design and Expression of the Multi-Component Protein Candidate against the Toxoplasma gondii Parasite from MIC13, GRA1, and SAG1 Antigens.

Background: We aimed to design a B and T cell recombinant protein vaccine of Toxoplasma gondii with in silico approach. MIC13 plays an important role in spreading the parasite in the host body. GRA1 causes the persistence of the parasite in the parasitophorous vacuole. SAG1 plays a role in host-cell adhesion and cell invasion. Methods: Amino acid positions 73-272 from MIC13, 71-190 from GRA1, and 101-300 from SAG1 were selected and joined with linker A(EAAAK)A. The structures, antigenicity, allergenicity, physicochemical properties, as well as codon optimization and mRNA structure of this recombinant protein called MGS1, were predicted using bioinformatics servers. The designed structure was synthesized and then cloned in pET28a (+) plasmid and transformed into Escherichia coli BL21. Results: The number of amino acids in this antigen was 555, and its antigenicity was estimated to be 0.6340. SDS-PAGE and Western blotting confirmed gene expression and successful production of the protein with a molecular weight of 59.56kDa. This protein will be used in our future studies as an anti-Toxoplasma vaccine candidate in animal models. Conclusion: In silico methods are efficient for understanding information about proteins, selecting immunogenic epitopes, and finally producing recombinant proteins, as well as reducing the time and cost of vaccine design.

Targeted delivery of a short antimicrobial peptide (CM11) against Helicobacter pylori gastric infection using concanavalin A-coated chitosan nanoparticles.

Helicobacter pylori is the cause of most cases of stomach ulcers and also causes some digestive cancers. The emergence and spread of antibiotic-resistant strains of H. pylori is one of the most important challenges in the treatment of its infections. The present study aims to develop a concanavalin A (ConA) coated chitosan (CS) nanocarrier-based drug delivery for the targeted release of peptides to the site of H. pylori infection. Accordingly, chitosan was used as an encapsulating agent for CM11 peptide delivery by applying ionotropic gelation method. Con-A was used for coating CS nanoparticles to target H. pylori. The CS NPs and ConA-CS NPs were characterized by FTIR, dynamic light scattering (DLS), and scanning electron microscopy (SEM). The MIC of CM11-loaded ConA-CS NPs against H. pylori SS1 strain was analyzed in vitro. In order to evaluate the treatment efficiency in vivo, a gastric infection model of H. pylori SS1 strain was established in mice and histopathological studies and IL-1ß cytokine assay were performed. Based on the results, the size frequency for CS NPs and ConA-CS NPs was about 200 and 350 nm, respectively. The prepared CM11-loaded ConA-CS NPs exhibited antibacterial activity against H. pylori SS1 strain with a concentration of 32 µg/ml. The highest healing process was observed in synthesized CM11-loaded ConA-CS NPs treatments and a significant decrease in IL-1ß was observed. Our findings highlight the potential of chitosan nanoparticles as a drug delivery vehicle in the treatment of gastric infection model of H. pylori SS1 strain.

Anti-parasitic activity of a chimeric peptide Cecropin A (2-8)-Melittin (6-9) (CM11) against tachyzoites of Toxoplasma gondii and the BALB/c mouse model of acute toxoplasmosis.

Toxoplasmosis is a zoonotic disease that infects most animals, including humans. Pyrimethamine/sulfadiazine is the standard treatment for toxoplasmosis. Although this treatment has been successful, it is often associated with side effects that cannot be tolerated. Therefore, various compounds have been proposed as alternative treatments for toxoplasmosis. Antimicrobial peptides (AMPs) act on various pathogens, from viruses to protozoa. The purpose of the present study was to evaluate the effects of CM11 on in vitro and in vivo Toxoplasma gondii infection. For in vitro experiments, VERO cells were treated with different concentrations of CM11 (1-128 µg/ml) compared to sulfadiazine (SDZ) (0.78-100 µg/ml). MTT and lactate dehydrogenase (LDH) assays evaluated the cell viability and plasma membrane integrity. Then, the inhibitory concentration (IC50) values were determined for treating tachyzoites of T. gondii before or on cells previously infected. Annexin V-FITC/propidium iodide (PI) staining was used to distinguish viable and apoptotic cells. The effect of CM11, SDZ, and a combination of CM11 and SDZ was evaluated in the BALB/c mouse model of acute toxoplasmosis. CM11 was effective on tachyzoites of T. gondii and had a time and dose-dependent manner. The results of the MTT assay showed that the CC50 values of CM11 and SDZ were estimated at 17.4 µg/ml and 62.3 µg/ml after 24-h, respectively. The inhibitory concentration (IC50) of CM11 and SDZ on infected cells was estimated at 1.9 µg/ml and 1.4 µg/ml after 24-h, respectively. The highest rate of apoptosis (early and late) in high concentrations of SDZ and CM11 was determined for tachyzoites (2.13 % and 13.88 %), non-infected VERO cells (6.1 % and 19.76 %), and infected VERO cells (7.45 % and 29.9 %), respectively. Treating infected mice with CM11 and a combination of CM11 and SDZ had increased survival time. Based on the mentioned results, it can be concluded that CM11 has a beneficial effect on tachyzoites of T. gondii in vitro. The result of the mouse model suggests that CM11, either alone or in combination with other chemotherapeutic agents, could be a potential therapeutic for toxoplasmosis. Hence, antimicrobial peptides could be applied as promising anti-toxoplasma agents for treating toxoplasmosis.

Molecular Docking, Anti-Biofilm & Antibacterial Activities and Therapeutic Index of mCM11 Peptide on Acinetobacter baumannii Strains.

Despite the huge efforts of microbiologists, infectious diseases have yet remained one of the leading causes of death in humans, further highlighting the research priority for controlling opportunistic pathogens. Many researchers have used antibacterial peptides to solve the problem of antibiotic resistance. This research is thus conducted to investigate the antibacterial and anti-biofilm activity of a novel modified cecropin-melittin 11-peptide with improved therapeutic properties and lower side effects. After synthesis and purification of mCM11 (NH2-WRLFRRILRVL-NH2) by solid-phase synthesis and HPLC methods, respectively, the antibacterial and biofilm inhibitory activities were explored in vitro. TMHMM was used to confirm the reaction of mCM11 on the plasma membrane of the prokaryotic cells. The interaction between mCM11 on Acinetobacter baumannii strains was investigated by molecular docking using ClusPro2.0. Hemolysis and therapeutic indexes were also calculated to quantify the relative safety and adverse effects of mCM11. According to the results, mCM11 has a high inhibitory and lethal effect on A. baumannii strains due to its cationic properties and new specific sequence. Molecular docking revealed the release of a significant amount of energy when mCM11 binds to the surface of A. baumannii in an appropriate site. The findings indicated that mCM11 IC50 (4 µg/mL) lysed 2.78% of RBCs; moreover, 8 strains of Acinetobacter baumannii showed a favorable therapeutic index. The mCM11 exhibits strong antibacterial and antibiofilm activities against A. baumannii strains, suggesting its potential therapeutic role in infections caused by these strains. Similar to its impact on A. baumannii, mCM11 could be a suitable alternative to antibiotics in combat against antibiotic-resistant bacteria in the in vivo experiments.

Multi-Epitope Vaccine Candidates Associated with Mannosylated Chitosan and LPS Conjugated Chitosan Nanoparticles Against Brucella Infection.

One promising approach to increase protection against infectious diseases is to use adjuvants that can selectively stimulate the immune responses. In this study, multi-epitope antigens associated with LPS loaded chitosan (LLC) as toll-like receptor agonist or mannosylated chitosan nanoparticle (MCN) as vaccine delivery system were evaluated for their ability to stimulate immune responses to Brucella infection in mice model. Our results indicated that the addition of MCN to our vaccine formulations significantly elicited IFN-γ and IL-2 cytokines and antibody titers, in comparison with the non-adjuvanted vaccine candidates. The present results indicated that multi-epitopes and their administration with LLC or MCN induced Th1 immune response. In addition, vaccine candidates containing MCN provided high percentage of protection against B. melitensis and B. abortus infection. Our results provided support to previous reports indicating that MCNs are attractive adjuvants and addition of this adjuvant to multi-epitopes antigens play an important role in the development of vaccine against Brucella.

Immunological evaluation of a novel multi-antigenic DNA vaccine encoding SAG1, SAG3, MIC4, GRA5, GRA7, AMA1and BAG1 against Toxoplasma gondii in BALB/c mice.

Many recent studies have been conducted to find new DNA vaccines based on Toxoplasma gondii antigens. DNA vaccines encoding complex of different antigens showed better immune responses compared to single antigen vaccine. In this study, we constructed a DNA vaccine encoding SAG1, SAG3, MIC4, GRA5, GRA7, AMA1 and BAG1 against T. gondii, and evaluated the immune response it induced in BALB/c mice. For this purposes, thirty BALB/c mice were randomly divided into three groups containing tenmice each. There were two negative control groups (PBSand pVAX1 vector) and one vaccination group (pVAX1-MAF, Multantigenic Fragment). On days 0, 14 and 28, the mice were immunized intramuscularly, and 5 weeks later they were challenged with T. gondii RH strain. The immune responses were evaluated using lymphocyte proliferation assay, T-cell subsets detection, and measurement of antibody and cytokine levels. The results showed that mice immunized with pVAX1-MAF developed high levels of IL-2, IL-12, IgG and IFN- γ as well as CD3+CD4+ T cells. In addition, the survival time of mice immunized by pVAX1-MAF was longer than that control mice. In conclusion, our results show that the multiple DNA vaccine encodingSAG1, SAG3, mic4, GRA5, GRA7, AMA and BAG1effectively enhanced humoral and cellular immune responses, and prolonged the survival time. Together this would suggest that further investigation may result in a promising candidate vaccine to treat toxoplasmosis.

Enhancement of immune responses by vaccine potential of three antigens, including ROP18, MIC4, and SAG1 against acute toxoplasmosis in mice.

Toxoplasma gondii (T. gondii) causes considerable financial losses in the livestock industry and can present serious threats to pregnant women, as well as immunocompromised patients. Therefore, it is required to design and produce an efficient vaccine for controlling toxoplasmosis. The present study aimed to evaluate the protective immunity induced by RMS protein (ROP18, MIC4, and SAG1) with Freund adjuvant, calcium phosphate nanoparticles (CaPNs), and chitosan nanoparticles (CNs) in BALB/c mice. The RMS protein was expressed in Escherichia coli (E. coli) and purified using a HisTrap HP column. Thereafter, cellular and humoral immunity was assessed by injecting RMS protein on days 0, 21, and 35 into four groups [RMS, RMS-chitosan nanoparticles (RMS-CNs), RMS-calcium phosphate nanoparticles (RMS-CaPNs), and RMS-Freund]. Phosphate buffered saline (PBS), CNs, CaPNs, and Freund served as the four control groups. The results displayed that vaccination with RMS protein and adjuvants significantly elicited the levels of specific IgG antibodies and cytokines against toxoplasmosis. There were high levels of total IgG, IgG2a, and IFN-γ in vaccinated mice, compared to those in the control groups, especially in the RMS-Freund, indicating a Th-1 type response. The vaccinated and control mice were challenged intraperitoneally with 1 × 103 tachyzoites of the T. gondii RH strain four weeks after the last injection, and in RMS-Freund and RMS-CaPNs groups, the highest increase in survival time was observed (15 days). The RMS can significantly increase Th1 and Th2 responses; moreover, multi-epitope vaccines with adjuvants can be a promising strategy for the production of a vaccine against toxoplasmosis.

Effects of aflatoxin B1 exposure on sperm in rodents: a systematic review and meta-analysis.

Exposure to aflatoxin B1 can be associated with reproductive toxicity, accompanied by decreased sperm concentration in animal models. The aim of this meta-analysis was to determine the correlation between aflatoxin B1 exposure and sperm concentrations of male rodents (both mice and rats). According to inclusion and exclusion criteria, 8 articles were selected to assess in the current meta-analysis. The random effects and pooled analysis indicated that sperm concentration was decreased in mice [MD sperm = -20.79×106/sperm/g testis (95%CI =-1.3 to -50.5)] and in rats [-24.34×106/sperm/g testis (95%CI: -7.60 to -44.35)] after exposure to aflatoxin B1 compared with control groups. A significant heterogeneity was found among studies (for mice I2=99.7%, %, P<0.000 and rats =I2=98.8, P<0.000). The findings of present meta-analysis showed the association between aflatoxin B1 exposure and a decrease in sperm concentration in rodents.

Rescuing humanity by antimicrobial peptides against colistin-resistant bacteria.

It has been about a century since the discovery of the first antibiotic, and during this period, several antibiotics were produced and marketed. The production of high-potency antibiotics against infections led to victories, but these victories were temporary. Overuse and misuse of antibiotics have continued to the point that humanity today is almost helpless in the fight against infection. Researchers have predicted that by the middle of the new century, there will be a dark period after the production of antibiotics that doctors will encounter antibiotic-resistant infections for which there is no cure. Accordingly, researchers are looking for new materials with antimicrobial properties that will strengthen their ammunition to fight antibiotic-resistant infections. One of the most important alternatives to antibiotics introduced in the last three decades is antimicrobial peptides (AMPs), which affect a wide range of microbes. Due to their different antimicrobial properties from antibiotics, AMPs can fight and kill MDR, XDR, and colistin-resistant bacteria through a variety of mechanisms. Therefore, in this study, we intend to use the latest studies to give a complete description of AMPs, the importance of colistin-resistant bacteria, and their resistance mechanisms, and represent impact of AMPs on colistin-resistant bacteria. KEY POINTS: • AMPs as limited options to kill colistin-resistant bacteria. • Challenge of antibiotics resistance, colistin resistance, and mechanisms. • What is AMPs in the war with colistin-resistant bacteria?

Potential diagnostic and prognostic of efferocytosis-related unwanted soluble receptors/ligands as new non-invasive biomarkers in disorders: a review.

Efferocytosis is the process by which apoptotic cells are removed without inflammation to maintain tissue homeostasis, prevent unwanted inflammatory responses, and inhibit autoimmune responses. Coordination of efferocytosis occurs via many surfaces and chemotactic molecules and adaptors. Recently, soluble positive or negative mediators of efferocytosis, have been more noticeable as non-invasive valuable biomarkers in prognosis and targeted therapy. These soluble factors can be detected in different bodily fluids, such as serum, plasma, and urine as a non-invasive method. There are lots of studies that have tried to show the importance of receptors and ligands in disorders; while a few studies tried to indicate the importance of soluble forms of receptors/ligands and their clinical aspects as a systemic compound and shedding of targets related to efferocytosis. Some of these soluble forms also can be as sensitive as specific biomarkers for certain diseases compared with routine biomarkers, such as soluble circulatory Lectin-like oxidized low-density lipoprotein receptor-1 vs. troponin T in the acute coronary syndrome. Thus, this review tried to gain more understanding about efferocytosis-related unwanted soluble receptors/ligands, their roles, the clinical significance, and potential for diagnosis, and prognosis related to different diseases.

A contemporary review on the important role of in silico approaches for managing different aspects of COVID-19 crisis.

In the last century, the emergence of in silico tools has improved the quality of healthcare studies by providing high quality predictions. In the case of COVID-19, these tools have been advantageous for bioinformatics analysis of SARS-CoV-2 structures, studying potential drugs and introducing drug targets, investigating the efficacy of potential natural product components at suppressing COVID-19 infection, designing peptide-mimetic and optimizing their structure to provide a better clinical outcome, and repurposing of the previously known therapeutics. These methods have also helped medical biotechnologists to design various vaccines; such as multi-epitope vaccines using reverse vaccinology and immunoinformatics methods, among which some of them have showed promising results through in vitro, in vivo and clinical trial studies. Moreover, emergence of artificial intelligence and machine learning algorithms have helped to classify the previously known data and use them to provide precise predictions and make plan for future of the pandemic condition. At this contemporary review, by collecting related information from the collected literature on valuable data sources; such as PubMed, Scopus, and Web of Science, we tried to provide a brief outlook regarding the importance of in silico tools in managing different aspects of COVID-19 pandemic infection and how these methods have been helpful to biomedical researchers.

NLRP3 inflammasome activation and oxidative stress status in the mild and moderate SARS-CoV-2 infected patients: impact of melatonin as a medicinal supplement.

The inflammasome as a multiprotein complex has a role in activating ASC and caspase-1 resulting in activating IL-1ß in various infections and diseases like corona virus infection in various tissues. It was shown that these tissues are affected by COVID-19 patients. According to the current evidence, melatonin is not veridical while possessing a high safety profile, however, it possesses indirect anti-viral actions owing to its anti-oxidation, anti-inflammation, and immune improving properties. This study aims to assess the impacts of melatonin as the complementary treatments on oxidative stress agents and inflammasome activation in patients with COVID-19. Melatonin supplement (9 mg daily, orally) was provided for the patients hospitalized with a COVID-19 analysis for 14 days. For measuring IL-10, IL-1ß, and TNF-α cytokines and malondialdehyde (MDA), nitric oxide (NO), and superoxide dismutase (SOD) level and the expression of CASP1 and ASC genes, blood samples were gathered from the individuals at the start and termination of the therapy. Our findings indicated that melatonin is used as a complementary treatment to reduce the levels of TNF-α and IL-1ß cytokines, MDA, and NO levels in COVID-19 patients and significantly increase SOD level, however, the levels of IL-10 cytokine possesses no considerable changes. The findings revealed that genes of CASP1 and ASC were dysregulated by melatonin regulating the inflammasome complex. Based on the findings of the current study, it is found that melatonin can be effective as a medicinal supplement in decreasing the inflammasome multiprotein complex and oxidative stress along with beneficial impacts on lung cytokine storm of COVID-19 patients.

Designing new nanoliposomal formulations and evaluating their effects on myeloid-derived suppressor cells and regulatory T cells in a colon cancer model aiming to develop an efficient delivery system for cancer treatment; an in vitro and in vivo study.

Regulfatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) are common immunosuppressive cells in the tumor microenvironment. These cells, through various mechanisms, inhibit antitumor immune responses and impede effective therapies. Therefore, designing an efficient protocol for inducing immune surveillance in tumors is highly recommended. Recently, nanoliposomes have provided broad-spectrum and state-of-the-art vehicles to deliver antigens or immune system compartments in immunotherapies. It has been shown that different lipids in the structure of liposomes and various liposomal formulations can affect immune responses in the tumor microenvironment. This study was aimed to evaluate the effects of four different liposomal formulations on MDSCs and Tregs in C26 tumor-bearing mice. To this end, after preparing liposomes, they were injected into tumor-inoculated mice and analyzed MDSC and Treg population and functions in spleen and tumor tissues. Results showed that 1,2-dioleoyl-3-trimethylammonium propane (DOTAP)-containing liposomes reduced MDSC population and activity in the spleen, but not tumor, compared with other groups significantly (p < 0.05 and p < 0.01, respectively). Moreover, DOTAP-containing liposomes reduced the expression of S100A8 and arginase-1 genes in splenic MDSCs (p < 0.05). In conclusion, we provided evidence that DOTAP-containing liposomes contributed to stimulating immune responses and provided a situation to inhibit immunosuppression in the tumor microenvironment.

Brucella antigens (BhuA, 7α-HSDH, FliC) in poly I:C adjuvant as potential vaccine candidates against brucellosis.

A promising strategy for controlling animal brucellosis is vaccination with commercial vaccine strains (Brucella melitensis Rev.1 and Brucella abortus RB51). Owing to safety concerns associated with these vaccines, developing a more effective and safe vaccine is essential. In this study, we examined the capacity of BhuA, 7α-HSDH or FliC antigens in the presence or absence of adjuvant in eliciting immune responses against brucellosis. After cloning, expression and purification, these proteins were used to examine immunologic responses. All immunized mice induced a vigorous IgG, with a predominant IgG2a response. Moreover, splenocytes of immunized mice proliferated and produced IL-2 and IFN-γ, suggesting the induction of cellular immunity. The high IgG2a/IgG1 ratio and IL-2 and IFN-γ indicated a Th1-oriented immune response in test groups. BhuA-, 7α-HSDH- or FliC- poly I:C formulations were the most effective at inducing Th1 immune response compared to groups immunized with naked proteins. Immunization with proteins protected mice against B. melitensis 16M and B. abortus 544. The proteins in adjuvant induced higher levels of protection than proteins only and exhibited similar degree of protection to live attenuated vaccines. Our results, for first time, introduced five potential candidates for subunit vaccine development against B. melitensis and B. abortus infection.

Efficacy of a Low Dose of Melatonin as an Adjunctive Therapy in Hospitalized Patients with COVID-19: A Randomized, Double-blind Clinical Trial.

BACKGROUND: Melatonin has been known as an anti-inflammatory agent and immune modulator that may address progressive pathophysiology of coronavirus disease 2019 (COVID-19). AIM OF THE STUDY: To evaluate the clinical efficacy of adjuvant, use of melatonin in patients with COVID-19. METHODS: This single-center, double-blind, randomized clinical trial included 74 hospitalized patients with confirmed mild to moderate COVID-19 at Baqiyatallah Hospital in Tehran, Iran, from April 25, 2020-June 5, 2020. Patients were randomly assigned in a 1:1 ratio to receive standard of care and standard of care plus melatonin at a dose of 3 mg three times daily for 14 d. Clinical characteristics, laboratory, and radiological findings were assessed and compared between two study groups at baseline and post-intervention. Safety and clinical outcomes were followed up for four weeks. RESULTS: A total of 24 patients in the intervention group and 20 patients in the control group completed the treatment. Compared with the control group, the clinical symptoms such as cough, dyspnea, and fatigue, as well as the level of CRP and the pulmonary involvement in the intervention group had significantly improved (p <0.05). The mean time of hospital discharge of patients and return to baseline health was significantly shorter in the intervention group compared to the control group (p <0.05). No deaths and adverse events were observed in both groups. CONCLUSIONS: Adjuvant use of melatonin has a potential to improve clinical symptoms of COVID-19 patients and contribute to a faster return of patients to baseline health.

In Silico Analysis of Inhibiting Papain-like Protease from SARS-CoV-2 by Using Plant-Derived Peptides.

SARS-CoV-2 is a corona virus that has been the cause for one of the deadliest pandemics of history, started since 2019. Suppressing the activity of the critical enzymes in the SARS-CoV-2 could potentially inhibit a vital step in viral life cycle. Papain-like protease (PLpro) could be regarded as a critical enzyme in viral replication of SARS-CoV-2. In this research, it was aimed to suppress the activity of PLpro enzyme by using potential plant-derived protease inhibitor peptides. For this purpose, 11 plant derived peptides that could potentially inhibit protease activity were selected from literature. The structures of the PLpro and the peptide ligands were acquired from PDB (protein data bank) and after structural optimization, were docked by using HADDOCK 2.4 program. Analyzing the results indicated that VcTI from Veronica hederifolia provides effective molecular interactions at both liable Zn site and classic active site of PLpro, making it a potential inhibitory ligand for this enzyme that could be used for halting the replication of SARS-CoV-2. Molecular dynamic assay confirmed that the selected receptor and ligand complex was stable. Future in vitro and in vivo investigations are required to verify the efficiency of this compound as a potential therapeutic against SARS-CoV-2 infection. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10989-021-10331-8.

Evaluation of Th1 and Th2 mediated cellular and humoral immunity in patients with COVID-19 following the use of melatonin as an adjunctive treatment.

Coronavirus (SARS-CoV-2) is spreading rapidly in the world and is still taking a heavy toll. Studies show that cytokine storms and imbalances in T-helper (Th)1/Th2 play a significant role in most acute cases of the disease. A number of medications have been suggested to treat or control the disease but have been discontinued due to their side effects. Melatonin, as an intrinsic molecule, possesses pharmacological anti-inflammatory and antioxidant properties that decreases in concentration with age; as a result, older people are more prone to various diseases. In this study, patients who were hospitalized with a diagnosis of coronavirus disease 2019 (COVID-19) were given a melatonin adjuvant (9 mg daily, orally) for fourteen days. In order to measure markers of Th1 and Th2 inflammatory cytokines (such as interleukin (IL)-2, IL-4, and interferon (IFN)-γ) as well as the expression of Th1 and Th2 regulatory genes (signal transducer and activator of transcription (STAT)4, STAT6, GATA binding protein 3 (GATA3), and T-box expressed in T cell (T-bet)), blood samples were taken from patients at the beginning and end of the treatment. Adjuvant therapy with melatonin controlled and reduced inflammatory cytokines in patients with COVID-19. Melatonin also controlled and modulated the dysregulated genes that regulate the humoral and cellular immune systems mediated by Th1 and Th2. In this study, it was shown for the first time that melatonin can be used as a medicinal adjuvant with anti-inflammatory mechanism to reduce and control inflammatory cytokines by regulating the expression of Th1 and Th2 regulatory genes in patients with COVID-19.

Conjugation of imipenem to silver nanoparticles for enhancement of its antibacterial activity against multi-drugresistant isolates of Pseudomonas aeruginosa.

Due to the broad-spectrum of antibiotic resistance, herein we investigated the possibility of using imipenemconjugated silver nanoparticles (IMP-AgNPs) against multidrug-resistant isolates of Pseudomonas aeruginosa. For this purpose, 200 clinical isolates were tested against different antibiotics to determine the antimicrobial susceptibility. To identify blaVIM and blaIMP resistance genes, PCR was used. The synthesized AgNPs and conjugants were characterized using UV-vis spectroscopy, XRD, SEM, TEM, DLS, and FTIR. The stability, drug release kinetics, cytotoxicity, hemolytic and apoptotic effects of NPs were also investigated. MIC of the imipenem, AgNPs, and conjugants were evaluated versus P. aeruginosa isolates. Finally, the effects of the IMP-AgNPs to heal burn wounds in rats was evaluated. According to the results, about 68% of isolates showed resistance to imipenem (MIC ≥ 64 µg/ml to ≥ 512 µg/ml). Analytical results verified the synthesis of AgNPs and IMP-AgNPs. A Dose-dependent decrease happened in terms of the MIC values of IMP-AgNPs were also affected by the existence of resistant genes. Low cytotoxic was observed regarding AgNPs which lead to apoptosis. The histopathological results showed a considerable epithelization in treated groups with IMPAgNPs. Accordingly, IMP-AgNPs can be considered as a powerful antibacterial agent to treat the infections caused by multidrug-resistant P. aeruginosa.

Antiviral peptides against Coronaviridae family: A review.

The Coronaviridae family comprises large enveloped single-stranded RNA viruses. The known human-infecting coronaviruses; severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), novel SARS-CoV-2, human coronavirus (HCoV)-NL63, HCoV-229E, HCoV-OC43 and HKU1 cause mild to severe respiratory infections. The viral diseases induced by mammalian and avian viruses from Coronaviridae family pose significant economic and public health burdens. Due to increasing reports of viral resistance, co-infections and the emergence of viral epidemics such as COVID-19, available antiviral drugs show low or no efficacy, and the production of new treatments or vaccines are also challenging. Therefore, demand for the development of novel antivirals has considerably increased. In recent years, antiviral peptides have generated increasing interest as they are from natural and computational sources, are highly specific and effective, and possess the broad-spectrum activity with minimum side effects. Here, we have made an effort to compile and review the antiviral peptides with activity against Coronaviridae family viruses. They were divided into different categories according to their action mechanisms, including binding/attachment inhibitors, fusion and entry inhibitors, viral enzyme inhibitors, replication inhibitors and the peptides with direct and indirect effects on the viruses. Reported studies suggest optimism with regard to the design and production of therapeutically promising antiviral drugs. This review aims to summarize data relating to antiviral peptides particularly with respect to their applicability for development as novel treatments.