Physiology, pharmacology and prospects for dipeptidilpeptidase-4 inhibitors use

Modern requirements for the treatment of type 2 diabetes mellitus (DM2) include not only achieving a glycemic control, but also reducing the risk of developing cardiovascular complications. Dipeptidyl peptidase 4 (DPP-4) inhibitors are inferior in the effectiveness to some other actively developing groups of hypoglycemic drugs (SGLT2 inhibitors and GLP-1 receptor agonists);however, they seem relevant at the present time.The aim of the study is to analyze the literature data on the therapeutic potential and results of the of DPP-4 inhibitors research.Materials and methods. When searching for the review article materials, the ing databases of PubMed, Google Scholar and e-Library were used. The search was carried out on the publications for the period from 2006 to 2022, using the following keywords: DPP-4 inhibitors;glucagonlike peptide-1 (GLP-1);glucose-dependent insulinotropic peptide (GIP);sitagliptin, and other drugs.Results. DPP-4 belongs to the serine proteases family and is involved in the degradation of various chemokines and peptide hormones, including incretins secreted by intestinal L-and K-cells - GLP-1 and GIP. They regulate a postprandial insulin secretion and a beta-cell function, modulate a fasting and postprandial glucagon secretion, regulate the eating behavior and have many pleiotropic (immunomodulatory, anti-inflammatory, antifibrotic, etc.) effects. DPP-4 inhibitors reduce an enzyme activity by 70-90%, increasing plasma incretin levels by 2-4 times and have been used to treat DM2 since 2006. Now there are 13 DPP-4 inhibitors on the market in different countries, differing primarily in pharmacokinetic parameters. They are actively used in the combination therapy for type 2 diabetes, increasing the glycemic control effectiveness without increasing the risk of hypoglycemia. The evidence is emerging about the therapeutic potential of DPP-4 inhibitors in COVID-19.Conclusion. A peroral form, an ability to create effective combinations with other hypoglycemic drugs without increasing the risk of hypoglycemia, the pleiotropic effects of DPP-4 inhibitors, make this group relevant at the present time.

A Case of Fever and Polymorphous Rash in a Patient with Recent Sars-Cov-2 Infection

Introduction. Multisystem inflammatory syndrome in adults (MIS-A) is a rare but potentially life-threatening sequel of SARS-CoV-2 infection, requiring early recognition and treatment. Nevertheless, it is often hard to distinguish MIS-A from other COVID-19-related hyperinflammatory complications. Case presentation. A 74-year-old male presented to the emergency department with persistent fever, diarrhea, altered consciousness, polymorphous rash with oral lesions and erythema of the palms and soles, with progressive exfoliation. The patient had been hospitalized for COVID-19 four weeks before and was suffering from chronic lymphocytic leukemia, diabetes and hypertension. During his recent hospital stay he received multiple courses of antibiotics and was discharged home with instructions to add sitagliptin and re-initiate therapy with ibrutinib. Upon re-admission, polymerase chain reaction test for SARS-CoV-2 was still positive and inflammatory markers were markedly elevated. Although MIS-A could not be excluded, a presumptive diagnosis of Stevens-Johnson Syndrome (SJS) was made, and the patient was treated empirically with intravenous immunoglobulin and high-dose methylprednisolone. SJS is usually considered an adverse drug reaction that affects the skin and mucous membranes. In this patient, MIS-A was also initially included in the differential diagnosis due to previous COVID-19, despite the patient's advanced age and lack of cardiac involvement or conjunctivitis. The patient only partially fulfilled current diagnostic criteria for MIS-A. Conclusions. SJS results from a dysregulated immune response and can have a similar presentation to MIS-A. A better characterization of both conditions is required particularly in older adults with comorbidities, to facilitate timely diagnosis and management and to reduce mortality.Copyright © ENS Editions. Tous droits reserves pour tous pays.

A Comprehensive Mini-review on COVID-19 Pathogenesis on Perspectives of Cytokine Storm and Recent Developments in Anti-Covid Nucleotide Analogues

The world has been rocked by the 2019 coronavirus disease (COVID-19), which has significantly changed our way of life. Despite the unusual measures taken, COVID-19 still exists and affects people all over the world. A remarkable amount of study has been done to find ways to combat the infection's unsurpassed level. No ground-breaking antiviral agent has yet been introduced to remove COVID-19 and bring about a return to normalcy, even though numerous pharmaceuticals and therapeutic technologies have been reused and discovered. The cytokine storm phenomenon is of utmost importance since fatality is strongly connected with the severity of the disease. This severe inflammatory phenomenon marked by increased amounts of inflammatory mediators can be targeted for saving patients' life. Our analysis demonstrates that SARS-CoV-2 specifically generates a lot of interleukin-6 (IL-6) and results in lymphocyte exhaustion. Tocilizumab is an IL-6 inhibitor that is currently thought to be both generally safe and effective. Additionally, corticosteroids, tumor necrosis factor (TNF)-blockers and Janus kinase (JAK) inhibitors could be effective and dependable methods to reduce cytokine-mediated storm in SARS-CoV-2 patients.Copyright © The Author(s) 2023.

Exploring novel targets of sitagliptin for type 2 diabetes mellitus: Network pharmacology, molecular docking, molecular dynamics simulation, and SPR approaches.

Background: Diabetes has become a serious global public health problem. With the increasing prevalence of type 2 diabetes mellitus (T2DM), the incidence of complications of T2DM is also on the rise. Sitagliptin, as a targeted drug of DPP4, has good therapeutic effect for T2DM. It is well known that sitagliptin can specifically inhibit the activity of DPP4 to promote insulin secretion, inhibit islet ß cell apoptosis and reduce blood glucose levels, while other pharmacological mechanisms are still unclear, such as improving insulin resistance, anti-inflammatory, anti-oxidative stress, and anti-fibrosis. The aim of this study was to explore novel targets and potential signaling pathways of sitagliptin for T2DM. Methods: Firstly, network pharmacology was applied to find the novel target most closely related to DPP4. Semi-flexible molecular docking was performed to confirm the binding ability between sitagliptin and the novel target, and molecular dynamics simulation (MD) was carried to verify the stability of the complex formed by sitagliptin and the novel target. Furthermore, surface-plasmon resonance (SPR) was used to explored the affinity and kinetic characteristics of sitagliptin with the novel target. Finally, the molecular mechanism of sitagliptin for T2DM was predicted by the enrichment analysis of GO function and KEGG pathway. Results: In this study, we found the cell surface receptor-angiotensin-converting enzyme 2 (ACE2) most closely related to DPP4. Then, we confirmed that sitagliptin had strong binding ability with ACE2 from a static perspective, and the stability of sitagliptin-ACE2 complex had better stability and longer binding time than BAR708-ACE2 in simulated aqueous solution within 50 ns. Significantly, we have demonstrated a strong affinity between sitagliptin and ACE2 on SPR biosensor, and their kinetic characteristics were "fast binding/fast dissociation". The guiding significance of clinical administration: low dose can reach saturation, but repeated administration was needed. Finally, there was certain relationship between COVID-19 and T2DM, and ACE2/Ang-(1-7)/Mas receptor (MasR) axis may be the important pathway of sitagliptin targeting ACE2 for T2DM. Conclusion: This study used different methods to prove that ACE2 may be another novel target of sitagliptin for T2DM, which extended the application of ACE2 in improving diabetes mellitus.

Evaluation of the anti-diabetic drug sitagliptin as a novel attenuate to SARS-CoV-2 evidence-based in silico: molecular docking and molecular dynamics.

The current outbreak of COVID-19 cases worldwide has been responsible for a significant number of deaths, especially in hospitalized patients suffering from comorbidities, such as obesity, diabetes, hypertension. The disease not only has prompted an interest in the pathophysiology, but also it has propelled a massive race to find new anti-SARS-CoV-2 drugs. In this scenario, known drugs commonly used to treat other diseases have been suggested as alternative or complementary therapeutics. Herein we propose the use of sitagliptin, an inhibitor of dipeptidyl peptidase-4 (DPP4) used to treat type-II diabetes, as an agent to block and inhibit the activity of two proteases, 3CLpro and PLpro, related to the processing of SARS-CoV-2 structural proteins. Inhibition of these proteases may possibly reduce the viral load and infection on the host by hampering the synthesis of new viruses, thus promoting a better outcome. In silico assays consisting in the modeling of the ligand sitagliptin and evaluation of its capacity to interact with 3CLpro and PLpro through the prediction of the ligand bioactivity, molecular docking, overlapping of crystal structures, and molecular dynamic simulations were conducted. The experiments indicate that sitagliptin can interact and bind to both targets. However, this interaction seems to be stronger and more stable to 3CLpro (ΔG = -7.8 kcal mol-1), when compared to PLpro (ΔG = -7.5 kcal mol-1). This study suggests that sitagliptin may be suitable to treat COVID-19 patients, beyond its common use as an anti-diabetic medication. In vivo studies may further support this hypothesis. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03406-w.

Potential Therapeutic Benefits of Metformin Alone and in Combination with Sitagliptin in the Management of Type 2 Diabetes Patients with COVID-19.

Type 2 diabetes mellitus (T2DM) is a potential risk factor for the development of COVID-19 and is associated with higher severity and mortality rates. T2DM patients are commonly treated with metformin monotherapy or metformin plus sitagliptin. In the present case-control, single-center cohort study, a total number of 112 T2DM patients suffering from COVID-19 and aged 44-62 years old were compared with 78 T2DM patients without COVID-19 and aged 42-56 years old. Both the patient group and the control group were allocated into four groups. Group A: T2DM patients with COVID-19 on metformin treatments plus standard therapy (n = 60); group B: T2DM patients with COVID-19 on metformin plus sitagliptin plus standard therapy (n = 52); group C: T2DM patients without COVID-19 on metformin treatments (n = 40); and group D: T2DM patients without COVID-19 on metformin plus sitagliptin (n = 38). The investigation duration was 2-3 weeks. Anthropometric measurements, serological and biochemical investigations, pulmonary radiological findings, and clinical outcomes were evaluated. Only 101 T2DM patients with COVID-19 continued the study, 71 (70.29%) with mild-moderate COVID-19 and 30 (29.7%) with severe COVID-19 were compared with 78 T2DM patients as a control. Inflammatory biomarkers (C reactive protein, ferritin, and procalcitonin), a lung injury biomarker (lactate dehydrogenase), and a coagulopathy biomarker (D-dimer) were elevated in severe COVID-19 patients compared with mild-moderate COVID-19 (p < 0.05) and T2DM patients (p < 0.05). However, metformin plus sitagliptin was more effective than metformin monotherapy in T2DM patients with COVID-19, as evidenced by the mitigation of oxidative stress, CT scan score, and clinical outcomes. The present study confirmed the protective effects of this combination against the development of COVID-19 severity, as most T2DM COVID-19 patients develop mild-moderate forms. Herein, the combination of metformin and sitagliptin may lead to more beneficial effects than metformin monotherapy.

Is sitagliptin effective for SARS-CoV-2 infection: false or true prophecy?

Coronavirus disease 2019 (Covid-19) is caused by severe acute respiratory syndrome type 2 (SARS-CoV-2). Covid-19 is characterized by hyperinflammation, oxidative stress, and multi-organ injury (MOI) such as acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Covid-19 is mainly presented with respiratory manifestations; however, extra-pulmonary manifestations may also occur. Extra-pulmonary manifestations of Covid-19 are numerous including: neurological, cardiovascular, renal, endocrine, and hematological complications. Notably, a cluster of differentiation 26 (CD26) or dipeptidyl peptidase-4 (DPP-4) emerged as a new receptor for entry of SARS-CoV-2. Therefore, DPP-4 inhibitors like sitagliptin could be effective in treating Covid-19. Hence, we aimed in the present critical review to assess the potential role of sitagliptin in Covid-19. DPP-4 inhibitors are effective against the increased severity of SARS-CoV-2 infections. Moreover, DPP-4 inhibitors inhibit the interaction between DPP-4 and scaffolding proteins which are essential for endosome formation and replication of SARS-CoV-2. Therefore, sitagliptin through attenuation of the inflammatory signaling pathway and augmentation of stromal-derived factor-1 (SDF-1) may decrease the pathogenesis of SARS-CoV-2 infection and could be a possible therapeutic modality in treating Covid-19 patients. In conclusion, the DPP-4 receptor is regarded as a potential receptor for the binding and entry of SARS-CoV-2. Inhibition of these receptors by the DPP-4 inhibitor, sitagliptin, can reduce the pathogenesis of the infection caused by SARS-CoV-2 and their associated activation of the inflammatory signaling pathways.

Repurposing Sitagliptin for COVID-19 in Adults: Clinical Benefits and An Approach for the Mechanism

Introduction: Dipeptidyl peptidase-4 (DPP4) has been shown to be a functional receptor for MERS-CoV. An interaction between the viral spike protein and DPP4 is thought to facilitate viral entry. We aimed to find out whether sitagliptin, a member of DPP4 inhibitors, would have beneficial effects in COVID-19 patients. Materials and Methods: In this single center retrospective study, we evaluated 58 patients of whom 16 were on sitagliptin treatment. Molecular docking studies were performed to identify possible interactions between ACE2 and sitagliptin. Results: Sitagliptin use shortened the time to clinical recovery about 3.5 and fastened viral clearance more than 5 days. Resolution of all symptoms was achieved on a mean±standard error (SE) of 2.50 ± 0.40 days in sitagliptin (+) group and 5.69 ± 0.61 days in sitagliptin (-) group (Log-rank test, p< 0.001). PCR tests for SARS-CoV-2 resulted negative in mean ± SE of 7.50 ± 0.98 days in sitagliptin (+) and 13.17 ± 1.07 days in sitagliptin (-) group (Log-rank test, p= 0.003). Compared to day 0, CRP, ferritin and D-dimer levels on days three, five, and seven were significantly lower whereas lymphocyte count was higher in sitagliptin (+) group. Conclusion: Our results suggest that sitagliptin seems to have a potential to be considered for the treatment of COVID-19.

CULTURAL BARRIERS AND PANDEMIC RESTRICTIONS RESULT IN A DELAYED DIAGNOSIS OF DRUG INDUCED LUPUS (DIL) AND SYSTEMIC LUPUS ERYTHEMATOSUS (SLE)

CASE: A 58-year-old female with a history of hypertension, type 2 diabetes and hyperlipidemia presented with a two- week history of abdominal pain and fevers. Per the patient, family history was unremarkable, and she denied alcohol, tobacco, or recreational drug use. She denied recent travel or sexual activity and had moved to the U.S. in the 1970s from Cambodia. Medications included amlodipine, atorvastatin, dapagliflozin, lisinopril, metformin and sitagliptin. Physical exam was notable for bilateral axillary lymphadenopathy, hepatomegaly, and right sided abdominal tenderness. Laboratory data was notable for microcytic anemia, thrombocytopenia, and elevated transaminases, D-dimer, and C- reactive protein. Urinalysis demonstrated microscopic hematuria and proteinuria. Imaging showed diffuse lymphadenopathy and hepatomegaly. Autoimmune work-up was strongly positive for ANA, anti-histone, and anti DS DNA. Kidney biopsy was suggestive of glomerulonephritis. Liver biopsy was suggestive of drug induced liver injury or autoimmune hepatitis. A diagnosis of DIL and SLE was not reached until additional historical data from the patient's son was provided on hospital day 4;namely that the patient had a 30-lb unintentional weight loss, took unknown herbal supplements and had a daughter who passed away from complications of lupus. IMPACT/DISCUSSION: DIL is a rare adverse reaction to many drugs that generally manifests with mild systemic symptoms such as low-grade fevers, anorexia, and fatigue and rarely involves classic symptoms of SLE such as skin findings and major organ involvement. Notably, DIL can unmask clinically silent SLE and thereby lead to lupus like syndromes. This patient presented with mild symptoms and underwent an extensive workup due to missing key historical data which led to a delayed diagnosis. Due to COVID-19 restrictions on visitation, it was not until hospital day 4 when the patient's son visited that the team became aware of an unintentional 30-lb weight loss, unknown herbal supplement use, and a family history of SLE. The lack of such critical information stemmed from the fact that we did not ask about the use of supplements properly and never revisited it in a different manner. The patient did not share the cause of her daughter's passing as she was unaware of it, which may speak to cultural limitations in sharing health information among family members. It is imperative that as clinicians we constantly revisit the history and diversify our questions. A more complete history would optimize our workup and limit unnecessary testing, including blood draws and painful biopsies, which unfortunately occurred in this patient. CONCLUSION: A thorough history is important to achieving a timely diagnosis and to avoid excessive testing and procedures. Revisiting the history is necessary to finding key information and clinicians should consider incorporating available family members early in the diagnostic work up, especially if the diagnosis is unclear.

Drug Repurposing: A Potentially Emerging Discipline

Drug repurposing is the remodeling of already existing drugs to reduce the time frame, costs, and efforts in developing a new novel drug. This strategy has secured significant momentum in the previous decade. It overcomes the snags and pitfalls in the traditional means of drug discovery. This core research strategy has now become the sole approach to containing many deadly diseases that have no cure in the present. In astound, for pandemics like COVID-19 that is spreading like a wildfire worldwide, large-scale research programs and trials have been carried out to identify and modify existing drugs to counter the novel virus. Thus, this technology of drug repurposing offers a new lease of life, and greatly promotes the progress of the medicine, health, and pharma sectors. The purpose of this study is to understand the current status of drug repurposing in the field of virology, bacteriology, mycology, and oncology for clinical translatability.

Molecular Docking Studies for Protein-Targeted Drug Development in SARS-CoV-2

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic and emergency. Currently, there is no therapeutic agent that has been proven effective against the virus. Objective: We investigated and screened for 401 antiviral compounds that could inhibit one or more of the three protein targets in SARS-CoV-2 chymotrypsin-like (3CL) protease, RNA-dependent RNA polymerase, and spike glycoprotein) using the in-silico approach. Methods: Lipinski’s rule of five was used as an initial screening for relevant compounds. Ligand preparation was conducted using JChem software and Schrödinger’s LigPrep module, while protein elucidation was conducted using AutoDockTools-1.5.6. Molecular docking was analyzed using Au-toDockVina. Results: Five antiviral compounds were obtained from each SARS-CoV-2 protein with ideal and potential binding energy as a candidate for target protein inhibition on SARS-CoV-2, TAK-981;lopinavir, mefloquine, and sitagliptin were potent inhibitors of 3CL protease;imatinib, relacatib, AZD7986, imatinib, and TAK-981 proteins showed potential as inhibitors of RdRp tetrandrine, and, selinexor, imatinib, lopinavir, and ciclesonide, showed potential as inhibitors of glycoprotein AZD7986. These compounds have better binding energy than the three comparator drugs, remdesivir, chloroquine, and hydroxychloroquine. Conclusion: We obtained several antiviral compounds with reliable binding energies to the SARS-CoV-2 proteins and potentially better efficacy than the three comparator drugs. Furthermore, this research will help accelerate the development of Covid-19 drugs.

Efficacy and Safety of Sitagliptin in the Treatment of COVID-19.

Background: Coronavirus disease 2019 (COVID-19) is associated with a high risk of mortality especially among diabetes mellitus (DM) patients. Effective treatments against COVID-19 can complement the vaccination effort worldwide. Many review articles studied the effects of the dipeptidyl peptidase 4 (DPP-4) inhibitors among COVID-19 patients and found conflicting results. This heterogeneity may be due to different systemic pleiotropic effects of different DPP-4 inhibitors. Sitagliptin appears to be one of the good DPP-4 inhibitors that have antiinflammatory and antithrombotic effect. Therefore, this review assessed the benefits and safety of sitagliptin in the treatment of COVID-19. Methods: A detailed literature review using the electronic databases of Pubmed and Google Scholar was conducted during July and August 2021 to find out studies that published in English language and discussed the role of sitagliptin for COVID-19 patients. Results: 14 articles were eligible and thus included in this narrative review. Nine of these articles agreed to the benefit of sitagliptin in the treatment of COVID-19, while 3 studies considered sitagliptin as non useful or even risky, and one study was neutral in its conclusion towards the usage of sitagliptin in COVID-19. Only one study focused on the safety of sitagliptin and found that it is safe. Conclusion: Sitagliptin has anti-inflammatory, antifibrotic and antiapoptotic properties; such effects may be beneficial in reducing risks of COVID-19. Sitagliptin has good safety and fair benefits to reduce mortality among DM patients with COVID-19. Further randomized clinical trials are needed to confirm these benefits especially among patients without DM.

Development of New Onset, Protracted Hyperglycemia Triggered by COVID-19 Vaccination with Ultimate Resolution in an Individual without Prior Dysglycemia

Introduction: Frequently, endocrinologists are asked for advice on COVID-19 vaccination. For patients with diabetes, promoting vaccination against COVID-19 is critical;research has shown a significantly increased risk of severe infection in these patients. Notably, there appears to be a physiological connection between COVID-19 infection and hyperglycemia. There have been multiple cases of patients developing hyperglycemia after contracting COVID-19. In contrast, there are few reported cases of new onset hyperglycemia developing after the COVID-19 vaccination. Case Description: We present the case of a 63-year-old woman with no significant past medical history. She maintained a healthy lifestyle and stable weight for several decades (BMI 24.3). She received her first dose of the Pfizer COVID-19 vaccination in December 2020. Frequent workplace testing (weekly, between 12/4/20 and 2/12/21) documented no evidence of COVID-19 infection, and no symptoms of COVID-19 had occurred at any time before or after immunization. Four days post-vaccination, she developed significant polyuria and polydipsia, but accepted a second dose 3 weeks later. The patient’s symptoms persisted for months and were accompanied by weight loss. Five months later, she finally sought medical attention. Her HbA1c and serum glucose were elevated (12.9% and 295 mg/dL, respectively). At her endocrinology appointment in May 2021, BMI was 22.4, consistent with her reported weight loss of 1 pound per week. Metformin (500 mg twice per day) and sitagliptin (100 mg per day) were prescribed and a low-carbohydrate diet was recommended. One week later, with fasting blood glucose between 114 - 188 mg/dL, sitagliptin was discontinued. The next week, fasting blood glucose between 71 - 95 mg/dL allowed metformin discontinuation. In September 2021, she reported continued weight loss (BMI 20.2), attributed to the low-carbohydrate diet. After 2 months off medication, both fasting and postprandial blood glucose were < 100 mg/dL. HbA1c (5.1%), C-peptide (1.1 ng/mL), and serum glucose (90 mg/dL) were all normal. She remains normoglycemic without medication. Discussion: There have been several reports of new-onset diabetes following COVID-19 vaccination. However, to date, we identified no published case reporting complete resolution of diabetes. We hypothesize that immune changes resulting from her COVID vaccine were associated with increases in inflammatory markers causing temporary beta cell toxicity. It is unclear what the impact of a booster will be on her glycemic control, therefore we recommend she remain vigilant for symptoms of hyperglycemia after getting her third dose.

In vitro Evaluation of Sitagliptin-HIV-1 Trans-activator Transcription Peptide Nano-formula for Antiviral Activity Against SARS-CoV-2: Drug Repurposing Approach

Background. The outbreak of COVID-19 pandemic in China regarded as a major health/economic hazard. The importance of coming up with mechanisms for preventing or treating COVID-19 has been felt across the world. This work aimed at examining the efficiency of Sitagliptin (SIT) and human immunodeficiency virus type 1 (HIV-1) trans-activator transcription peptide (TAT) against SARS-CoV-2. Methods. SIT-TAT nano-conjugates were prepared according to a full three-factor bi-level (23) factorial design. SIT concentration (mM, X1), TAT concentration (mM, X2), and pH (X3) were selected as the factors. Particle size (nm, Y1) and zeta potential (mV, Y2) were assessed as responses. Characterization of the optimized formula for Fourier-transformed infrared (FTIR) and Transmission electron microscope was carried out. In addition, IC50 in Vero E6 cells, In vitro 3CL-protease inhibition and docking tests were investigated. Results. The prepared complex's formula was as follows 1: 1 SIT: TAT molar ratio, whereas zeta potential and particle size values were at 34.17 mV and 97.19 nm, respectively. This combination did exhibit its antiviral potentiality against SARS-CoV-2 via IC50 values of 9.083 5.415, and 16.14 μM for TAT, SIT-TAT, and SIT, respectively. In addition, the complex SIT-TAT showed a significant (P < 0.001) viral-3CL-protease inhibitory effect (IC50 = 3.959 μM ± 0.011) in comparison to isolated components (IC50 = 10.93 μM ± 0.25) and TAT (IC50 = 8.128 μM ± 0.42). This was further confirmed via in silico study. Molecular docking investigation has shown promising binding affinity of the formula components towards SARS-CoV-2 main protease (3-CL). Conclusion. While offering significant binding interactions with protein's key pocket residues, an optimized formulation of SIT-TAT could guarantee both the enhanced delivery to the target cells and the improved cellular uptake. The presented findings would guarantee further investigations regarding formula optimization against SARS-CoV-2.

Sitagliptin combined hiv-tat as potential therapeutic targeting of sars-cov-2 virus

Background and Objective: The outbreak of the COVID-19 pandemic in China regarded as a major health/economic hazard. The importance of coming up with mechanisms for preventing or treating SARS-CoV-2 infection has been felt across the world. This work aimed at examining the efficiency of Sitagliptin (SIT) and Human Immunodeficiency Virus type 1 (HIV-1) Trans-Activator Transcription peptide (TAT) against SARS-CoV-2 virus. Materials and Methods: Antiviral activity against SARS-CoV-2 propagated in Vero E6 cells, 3CL-protease inhibition activity and docking studies were examined. Eight formulae have been created using Design-Expert® Software to find the smallest complex size with the highest charge. The optimized formula was obtained then tested for antiviral activity. Results: According to the results, the prepared complex’s formula was as follows 1: 1 SIT: TAT molar ratio, whereas zeta potential and particle size values were at 34.17 mV and 97.19 nm, respectively. This combination did exhibit its antiviral potentiality against SARS-CoV-2 via IC50 values of 9.083 5.415 and 16.14 µM for TAT, SIT-TAT and SIT, respectively. In addition, the complex SIT-TAT showed a significant (p<0.001) viral-3CL-protease inhibitor effect (IC50 = 3.959±0.011 µM) in comparison to isolated components (IC50 = 10.93±0.25 µM) and TAT (IC50 = 8.128±0.42 µM). This was further confirmed via in silico study. Molecular docking investigation has shown promising binding affinity of the formula components towards SARS-CoV-2 main protease (3-CL). Conclusion: SIT-TAT could guarantee an enhanced delivery to the target cells, improved cellular uptake and synergistic blockage of the target active site. Results of this study confirm the efficacy of the Sitagliptin HIV TAT complex in the suppression of SARS-CoV2 virus multiplication.

In silico drug repositioning against human NRP1 to block SARS-CoV-2 host entry.

Despite COVID-19 turned into a pandemic, no approved drug for the treatment or globally available vaccine is out yet. In such a global emergency, drug repurposing approach that bypasses a costly and long-time demanding drug discovery process is an effective way in search of finding drugs for the COVID-19 treatment. Recent studies showed that SARS-CoV-2 uses neuropilin-1 (NRP1) for host entry. Here we took advantage of structural information of the NRP1 in complex with C-terminal of spike (S) protein of SARS-CoV-2 to identify drugs that may inhibit NRP1 and S protein interaction. U.S. Food and Drug Administration (FDA) approved drugs were screened using docking simulations. Among top drugs, well-tolerated drugs were selected for further analysis. Molecular dynamics (MD) simulations of drugs-NRP1 complexes were run for 100 ns to assess the persistency of binding. MM/GBSA calculations from MD simulations showed that eltrombopag, glimepiride, sitagliptin, dutasteride, and ergotamine stably and strongly bind to NRP1. In silico Alanine scanning analysis revealed that Tyr297, Trp301, and Tyr353 amino acids of NRP1 are critical for drug binding. Validating the effect of drugs analyzed in this paper by experimental studies and clinical trials will expedite the drug discovery process for COVID-19.

Impact of Sitagliptin on Non-diabetic Covid-19 Patients.

OBJECTIVES: In coronavirus disease 2019 (Covid-19), SARS-CoV-2 may use dipeptidyl peptidase 4 (DPP4) as an entry-point in different tissues expressing these receptors. DPP4 inhibitors (DPP4Is), also named gliptins, like sitagliptin, have anti-inflammatory and antioxidant effects, thereby lessen inflammatory and oxidative stress in diabetic Covid-19 patients. Therefore, the present study aimed to illustrate the potential beneficial effect of sitagliptin in managing Covid-19 in non-diabetic patients. METHODS: A total number of 89 patients with Covid-19 were recruited from a single center at the time of diagnosis. The recruited patients were assigned according to the standard therapy for Covid-19 and our interventional therapy into two groups; Group A: Covid-19 patients on the standard therapy (n=40) and Group B: Covid-19 patients on the standard therapy plus sitagliptin (n=49). The duration of this interventional study was 28 days according to the guideline in managing patients with Covid-19. Routine laboratory investigations, serological tests, Complete Blood Count (CBC), C-reactive Protein (CRP), D-dimer, lactate dehydrogenase (LDH), and serum ferritin were measured to observed Covid-19 severity and complications. Lung Computed Tomography (CT) and clinical scores were evaluated. RESULTS: The present study illustrated that sitagliptin as an add-on to standard therapy improved clinical outcomes, radiological scores, and inflammatory biomarkers than standard therapy alone in non-diabetic patients with Covid-19 (P<0.01). CONCLUSION: Sitagliptin as an add-on to standard therapy in managing non-diabetic Covid-19 patients may have a robust beneficial effect by modulating inflammatory cytokines with subsequent good clinical outcomes.

Dipeptidyl peptidase 4 inhibitors: Applications in innate immunity?

Dipeptidyl peptidase (DPP)-4 inhibitors are a class of orally available, small molecule inhibitors that prolong the insulinotropic activity of the incretin hormone glucagon-like peptide-1 (GLP-1) and are highly effective for the treatment of Type-2 diabetes. DPP4 can also cleave several immunoregulatory peptides including chemokines. Emerging evidence continues to implicate DPP4 inhibitors as immunomodulators, with recent findings suggesting DPP4 inhibitors modify specific aspects of innate immunity. This review summarises recent insights into how DPP4 inhibitors could be implicated in endothelial, neutrophil and monocyte/macrophage mediated immunity. Additionally, this review highlights additional avenues of research with DPP4 inhibitors in the context of the COVID-19 pandemic.

Evaluation of the Antiviral Activity of Sitagliptin-Glatiramer Acetate Nano-Conjugates against SARS-CoV-2 Virus.

The outbreak of the COVID-19 pandemic in China has become an urgent health and economic challenge. There is a current race for developing strategies to treat and/or prevent COVID-19 worldwide. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the strain of coronavirus that causes COVID-19. The aim of the present work was to evaluate the efficacy of the combined complex (nano-conjugates) of two FDA-approved drugs, sitagliptin (SIT) and glatiramer acetate (GA), against a human isolate of the SARS-CoV-2 virus. SIT-GA nano-conjugates were prepared according to a full three-factor bilevel (23) factorial design. The SIT concentration (mM, X1), GA concentration (mM, X2), and pH (X3) were selected as the factors. The particle size (nm, Y1) and zeta potential (mV, Y2) were assessed as responses. Characterization of the optimized formula for the Fourier-transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM) was carried out. In addition, the half-maximal inhibitory concentration (IC50) in Vero-E6 epithelial cells previously infected with the virus was investigated. The results revealed that the optimized formula of the prepared complex was a 1:1 SIT:GA molar ratio at a pH of 10, which met the required criteria with a desirability value of 0.878 and had a particle size and zeta potential at values of 77.42 nm and 27.67 V, respectively. The SIT-GA nano-complex showed antiviral potential against an isolate of SARS-CoV-2 with IC50 values of 16.14, 14.09, and 8.52 µM for SIT, GA, and SIT-GA nano-conjugates, respectively. Molecular docking has shown that the formula's components have a high binding affinity to the COVID 3CL protease, essential for coronavirus replication, paralleled by 3CL protease inhibition (IC50 = 2.87 µM). An optimized formulation of SIT-GA could guarantee both enhanced deliveries to target cells and improved cellular uptake. Further clinical studies are being carried out to validate the clinical efficacy of the optimized formulation against SARS-CoV-2.

Sitagliptin: a potential drug for the treatment of COVID-19?

Recently, an outbreak of a fatal coronavirus, SARS-CoV-2, has emerged from China and is rapidly spreading worldwide. Possible interaction of SARS-CoV-2 with DPP4 peptidase may partly contribute to the viral pathogenesis. An integrative bioinformatics approach starting with mining the biomedical literature for high confidence DPP4-protein/gene associations followed by functional analysis using network analysis and pathway enrichment was adopted. The results indicate that the identified DPP4 networks are highly enriched in viral processes required for viral entry and infection, and as a result, we propose DPP4 as an important putative target for the treatment of COVID-19. Additionally, our protein-chemical interaction networks identified important interactions between DPP4 and sitagliptin. We conclude that sitagliptin may be beneficial for the treatment of COVID-19 disease, either as monotherapy or in combination with other therapies, especially for diabetic patients and patients with pre-existing cardiovascular conditions who are already at higher risk of COVID-19 mortality.