Anti-HIV drugs: 25 compounds approved within 25 years after the discovery of HIV

New Therapies and Strategies to Curb HIV Infections with a Focus on Macrophages and Reservoirs

More than 80 million people worldwide have been infected with the human immunodeficiency virus (HIV). There are now approximately 39 million individuals living with HIV/acquired immunodeficiency syndrome (AIDS). Although treatments against HIV infection are available, AIDS remains a serious disease. Combination antiretroviral therapy (cART), also known as highly active antiretroviral therapy (HAART), consists of treatment with a combination of several antiretroviral drugs that block multiple stages in the virus replication cycle. However, the increasing usage of cART is inevitably associated with the emergence of HIV drug resistance. In addition, the development of persistent cellular reservoirs of latent HIV is a critical obstacle to viral eradication since viral rebound takes place once anti-retroviral therapy (ART) is interrupted. Thus, several efforts are being applied to new generations of drugs, vaccines and new types of cART. In this review, we summarize the antiviral therapies used for the treatment of HIV/AIDS, both as individual agents and as combination therapies, and highlight the role of both macrophages and HIV cellular reservoirs and the most recent clinical studies related to this disease.

Enzymatic activity of HIV-1 protease defines migration of tumor cells in vitro and enhances their metastatic activity in vivo

Overexpression of aspartic proteases, as cathepsin D, is an independent marker of poor prognosis in breast cancer, correlated with the incidence of clinical metastasis. We aimed to find if HIV-1 aspartic protease (PR) can play a similar role. Murine adenocarcinoma 4T1luc2 cells were transduced with lentivirus encoding inactivated drug-resistant PR, generating subclones PR20.1 and PR20.2. Subclones were assessed for production of reactive oxygen species (ROS), expression of epithelial-mesenchymal transition (EMT) factors, and in vitro migratory activity in the presence or absence of antioxidant N-acetyl cysteine and protease inhibitors. Tumorigenic activity was evaluated by implanting cells into BALB/c mice and following tumor growth by calipering and bioluminescence imaging in vivo, and metastases, by organ imaging ex vivo. Both subclones expressed PR mRNA, and PR20.2, also the protein detected by Western blotting. PR did not induce production of ROS, and had no direct effect on cell migration rate, however, treatment with inhibitors of drug-resistant PR suppressed the migratory activity of both subclones. Furthermore, expression of N-cadherin and Vimentin in PR20.2 cells and their migration were enhanced by antioxidant treatment. Sensitivity of in vitro migration to protease inhibitors and to antioxidant, known to restore PR activity, related the effects to the enzymatic activity of PR. In vivo, PR20.2 cells demonstrated higher tumorigenic and metastatic activity than PR20.1 or parental cells. Thus, HIV-1 protease expressed in breast cancer cells determines their migration in vitro and metastatic activity in vivo. This effect may aggravate clinical course of cancers in people living with HIV-1.

Synthesis, in vitro Anti-HIV-1RT evaluation, molecular modeling, DFT and acute oral toxicity studies of some benzotriazole derivatives

This study synthesized and evaluated a series of benzotriazole derivatives denoted 3(a-j) and 6(a-j) for their anti-HIV-1 RT activities compared to the standard drug efavirenz. Notably, compound 3 h, followed closely by 6 h, exhibited significant anti-HIV-1 RT efficacy relative to the standard drug. In vivo oral toxicity studies were conducted for the most active compound 3 h, confirming its nontoxic nature to ascertain the safety profile. By employing molecular docking techniques, we explored the potential interactions between the synthesized compounds (ligands) and a target biomolecule (protein)(PDB ID 1RT2) at the molecular level. We undertook the molecular dynamics study of 3 h, the most active compound, within the active binding pocket of the cocrystallized structure of HIV-1 RT (PDB ID 1RT2). We aimed to learn more about how biomolecular systems behave, interact, and change at the atomic or molecular level over time. Finally, the DFT-derived HOMO and LUMO orbitals, as well as analysis of the molecular electrostatic potential map, aid in discerning the reactivity characteristics of our molecule.

Aminopyrimidine Derivatives as Multiflavivirus Antiviral Compounds Identified from a Consensus Virtual Screening Approach

Around three billion people are at risk of infection by the dengue virus (DENV) and potentially other flaviviruses. Worldwide outbreaks of DENV, Zika virus (ZIKV), and yellow fever virus (YFV), the lack of antiviral drugs, and limitations on vaccine usage emphasize the need for novel antiviral research. Here, we propose a consensus virtual screening approach to discover potential protease inhibitors (NS3pro) against different flavivirus. We employed an in silico combination of a hologram quantitative structure-activity relationship (HQSAR) model and molecular docking on characterized binding sites followed by molecular dynamics (MD) simulations, which filtered a data set of 7.6 million compounds to 2,775 hits. Lastly, docking and MD simulations selected six final potential NS3pro inhibitors with stable interactions along the simulations. Five compounds had their antiviral activity confirmed against ZIKV, YFV, DENV-2, and DENV-3 (ranging from 4.21 ± 0.14 to 37.51 ± 0.8 μM), displaying aggregator characteristics for enzymatic inhibition against ZIKV NS3pro (ranging from 28 ± 7 to 70 ± 7 μM). Taken together, the compounds identified in this approach may contribute to the design of promising candidates to treat different flavivirus infections.

Current insights and molecular docking studies of HIV-1 reverse transcriptase inhibitors

Human immunodeficiency virus (HIV) causes acquired immunodeficiency syndrome (AIDS), a lethal disease that is prevalent worldwide. According to the Joint United Nations Programme on HIV/AIDS (UNAIDS) data, 38.4 million people worldwide were living with HIV in 2021. Viral reverse transcriptase (RT) is an excellent target for drug intervention. Nucleoside reverse transcriptase inhibitors (NRTIs) were the first class of approved antiretroviral drugs. Later, a new type of non-nucleoside reverse transcriptase inhibitors (NNRTIs) were approved as anti-HIV drugs. Zidovudine, didanosine, and stavudine are FDA-approved NRTIs, while nevirapine, efavirenz, and delavirdine are FDA-approved NNRTIs. Several agents are in clinical trials, including apricitabine, racivir, elvucitabine, doravirine, dapivirine, and elsulfavirine. This review addresses HIV-1 structure, replication cycle, reverse transcription, and HIV drug targets. This study focuses on NRTIs and NNRTIs, their binding sites, mechanisms of action, FDA-approved drugs and drugs in clinical trials, their resistance and adverse effects, their molecular docking studies, and highly active antiretroviral therapy (HAART).

In Silico Pharmacokinetics, Molecular Docking and Molecular Dynamics Simulation Studies of Nucleoside Analogs for Drug Discovery- A Mini Review

Nucleoside analogs have been widely used as antiviral, antitumor, and antiparasitic agents due to their ability to inhibit nucleic acid synthesis. Adenosine, cytidine, guanosine, thymidine and uridine analogs such as didanosine, vidarabine, remdesivir, gemcitabine, lamivudine, acyclovir, abacavir, zidovusine, stavudine, and idoxuridine showed remarkable anticancer and antiviral activities. In our previously published articles, our main intention was to develop newer generation nucleoside analogs with acylation-induced modification of the hydroxyl group and showcase their biological potencies. In the process of developing nucleoside analogs, in silico studies play an important role and provide a scientific background for biological data. Molecular interactions between drugs and receptors followed by assessment of their stability in physiological environments, help to optimize the drug development process and minimize the burden of unwanted synthesis. Computational approaches, such as DFT, FMO, MEP, ADMET prediction, PASS prediction, POM analysis, molecular docking, and molecular dynamics simulation, are the most popular tools to culminate all preclinical study data and deliver a molecule with maximum bioactivity and minimum toxicity. Although clinical drug trials are crucial for providing dosage recommendations, they can only indirectly provide mechanistic information through researchers for pathological, physiological, and pharmacological determinants. As a result, in silico approaches are increasingly used in drug discovery and development to provide mechanistic information of clinical value. This article portrays the current status of these methods and highlights some remarkable contributions to the development of nucleoside analogs with optimized bioactivity.

Hydroxyalkynyl uracil derivatives as NNRTIs against HIV-1: in silico predictions, synthesis, docking and molecular dynamics simulation studies

To improve rationally the efficacy of the non-nucleoside human immunodeficiency virus (HIV-1) inhibitors, it is important to have a precise and detailed understanding of the HIV-1 reverse transcriptase (RT) and inhibitor interactions. For the 1-[(2-hydroxyethoxy) methyl]-6-(phenylthio) thymine (HEPT) type of nucleoside reverse transcriptase inhibitors (NNRTIs), the H-bond between the N-3H of the inhibitor and the backbone carbonyl group of K101 represents the major hydrophilic interaction. This H-bond contributes to the NNRTI binding affinity. The descriptor analyses of different uracil derivatives proved their good cell internalization. The bioactivity score reflected higher drug likeness score and the ligands showed interesting docking results. All molecules were deeply buried and stabilized into the allosteric site of HIV-1 RT. For majority of molecules, residues Lys101, Lys103, Tyr181 and Tyr188 were identified as key protein residues responsible for generation of H-bond and major interactions were similar to all known NNRTIs while very few molecules interacted with residues Phe227 and Tyr318. The TOPKAT protocol available in Discovery Studio 3.0 was used to predict the pharmacokinetics of the designed uracil derivatives in the human body. The molecular dynamics (MD) and post-MD analyses results reflected that the complex HIVRT:5 appeared to be more stable than the complex HIVRT:HEPT, where HEPT was used as reference. Different uracil derivatives have been synthesized by using uracil as starting material and commercially available propargyl bromide. The N-1 derivative of uracil was further reacted with sodamide and different aldehydes/ketones bearing alkyl and phenyl ring to obtain hydroxyalkynyl uracil derivatives as NNRTIs.Communicated by Ramaswamy H. Sarma.

Real-Life Experience on Dolutegravir and Lamivudine as Initial or Switch Therapy in a Silver Population Living with HIV

BACKGROUND

Clinical trials and real-life studies have granted the efficacy and safety of dolutegravir and lamivudine (DTG/3TC) in naïve and experienced people living with HIV (PLWH), but there are no long-term data in elderly people. We herein describe our real-life cohort of PLWH who were ≥65 years of age (PLWH ≥ 65) who started or were switched to DTG/3TC, single-tablet regimen, or DTG plus 3TC.

METHODS

We considered laboratory/clinical parameter changes from the baseline to the last follow-up time point available for each person by the paired Wilcoxon test and analyzed factors associated with virological failure (VF) and discontinuation.

RESULTS

We included 112 PLWH with a median age of 66 (IQR: 65-70) years, 77.6% males; 84.8% of people had multimorbidity, 34.8% were on polypharmacy, and only 5.4% were naïve to treatment. Reasons to be switched to DTG/3TC were: abacavir removal (38.7%), treatment simplification (33.1%), and PI discontinuation (28.2%). The median treatment durability was 6 (IQR: 5.4-7) years. No significant changes were detected in metabolic, renal, immunological, or cardiovascular biomarkers during follow-up. HIV RNA undetectability was maintained in 104 (92.8%) individuals for whom follow-up evaluation was available. We observed eight discontinuations (two deaths, two VFs, two early intolerances, one significant weight gain, and one switch to long-acting therapy). No factors were significantly associated with VF or discontinuation.

CONCLUSIONS

This is the first study on DTG/3TC in PLWH ≥ 65 with a follow-up longer than 5 years. DTG/3TC was found to be safe and effective, neutral on metabolic parameters, and with a low discontinuation rate for toxicity or VF.

Current ARTs, Virologic Failure, and Implications for AIDS Management: A Systematic Review

Antiretroviral therapies (ARTs) have revolutionized the management of human immunodeficiency virus (HIV) infection, significantly improved patient outcomes, and reduced the mortality rate and incidence of acquired immunodeficiency syndrome (AIDS). However, despite the remarkable efficacy of ART, virologic failure remains a challenge in the long-term management of HIV-infected individuals. Virologic failure refers to the persistent detectable viral load in patients receiving ART, indicating an incomplete suppression of HIV replication. It can occur due to various factors, including poor medication adherence, drug resistance, suboptimal drug concentrations, drug interactions, and viral factors such as the emergence of drug-resistant strains. In recent years, extensive efforts have been made to understand and address virologic failure in order to optimize treatment outcomes. Strategies to prevent and manage virologic failure include improving treatment adherence through patient education, counselling, and supportive interventions. In addition, the regular monitoring of viral load and resistance testing enables the early detection of treatment failure and facilitates timely adjustments in ART regimens. Thus, the development of novel antiretroviral agents with improved potency, tolerability, and resistance profiles offers new options for patients experiencing virologic failure. However, new treatment options would also face virologic failure if not managed appropriately. A solution to virologic failure requires a comprehensive approach that combines individualized patient care, robust monitoring, and access to a range of antiretroviral drugs.

Recent Updates on Viral Oncogenesis: Available Preventive and Therapeutic Entities

Human viral oncogenesis is a complex phenomenon and a major contributor to the global cancer burden. Several recent findings revealed cellular and molecular pathways that promote the development and initiation of malignancy when viruses cause an infection. Even, antiviral treatment has become an approach to eliminate the viral infections and prevent the activation of oncogenesis. Therefore, for a better understanding, the molecular pathogenesis of various oncogenic viruses like, hepatitis virus, human immunodeficiency viral (HIV), human papillomavirus (HPV), herpes simplex virus (HSV), and Epstein-Barr virus (EBV), could be explored, especially, to expand many potent antivirals that may escalate the apoptosis of infected malignant cells while sparing normal and healthy ones. Moreover, contemporary therapies, such as engineered antibodies antiviral agents targeting signaling pathways and cell biomarkers, could inhibit viral oncogenesis. This review elaborates the recent advancements in both natural and synthetic antivirals to control viral oncogenesis. The study also highlights the challenges and future perspectives of using antivirals in viral oncogenesis.

Solubility, Crystallization, and Characterization of Cytidine Sulfate

Cytidine is an important kind of nucleoside that can be applied to drug development and food industry. Cytidine sulfate is one of its popular forms, which is promising as a medicinal intermediate, especially in antiviral and antitumor drugs. Product refining is the key point of industrial development, and crystallization is a significant way of refining. In this work, the solubility of cytidine sulfate in pure water from 278.15 to 328.15 K and in water-ethanol binary solvents at 298.15 K was measured by the UV spectroscopic method. The solubility data were correlated with temperature and solvent composition using the modified Apelblat, van't Hoff, and CNIBS/R-K equations. On this basis, we investigated and compared three crystallization processes, and the coupling method was developed to prepare crystals with a large particle size, concentrated distribution, and high yield and packing density. In addition, the structure and stability of the products were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and dynamic vapor sorption analysis. It was found that cytidine sulfate has only one crystal form in our research process, and the product of coupling crystallization is stable and favorable for industrial development.

Fluorine in anti-HIV drugs approved by FDA from 1981 to 2023

Human immunodeficiency virus (HIV) is the etiological agent of acquired immunodeficiency syndrome (AIDS). Nowadays, FDA has approved over thirty antiretroviral drugs grouped in six categories. Interestingly, one-third of these drugs contain different number of fluorine atoms. The introduction of fluorine to obtain drug-like compounds is a well-accepted strategy in medicinal chemistry. In this review, we summarized 11 fluorine-containing anti-HIV drugs, focusing on their efficacy, resistance, safety, and specific roles of fluorine in the development of each drug. These examples may be of help for the discovery of new drug candidates bearing fluorine in their structures.

Pathophysiology and mechanisms of hearing impairment related to neonatal infection diseases

The inner ear, the organ of equilibrium and hearing, has an extraordinarily complex and intricate arrangement. It contains highly specialized structures meticulously tailored to permit auditory processing. However, hearing also relies on both peripheral and central pathways responsible for the neuronal transmission of auditory information from the cochlea to the corresponding cortical regions. Understanding the anatomy and physiology of all components forming the auditory system is key to better comprehending the pathophysiology of each disease that causes hearing impairment. In this narrative review, the authors focus on the pathophysiology as well as on cellular and molecular mechanisms that lead to hearing loss in different neonatal infectious diseases. To accomplish this objective, the morphology and function of the main structures responsible for auditory processing and the immune response leading to hearing loss were explored. Altogether, this information permits the proper understanding of each infectious disease discussed.

Antiretroviral Treatment of HIV-2 Infection: Available Drugs, Resistance Pathways, and Promising New Compounds

Currently, it is estimated that 1-2 million people worldwide are infected with HIV-2, accounting for 3-5% of the global burden of HIV. The course of HIV-2 infection is longer compared to HIV-1 infection, but without effective antiretroviral therapy (ART), a substantial proportion of infected patients will progress to AIDS and die. Antiretroviral drugs in clinical use were designed for HIV-1 and, unfortunately, some do not work as well, or do not work at all, for HIV-2. This is the case for non-nucleoside reverse transcriptase inhibitors (NNRTIs), the fusion inhibitor enfuvirtide (T-20), most protease inhibitors (PIs), the attachment inhibitor fostemsavir and most broadly neutralizing antibodies. Integrase inhibitors work well against HIV-2 and are included in first-line therapeutic regimens for HIV-2-infected patients. However, rapid emergence of drug resistance and cross-resistance within each drug class dramatically reduces second-line treatment options. New drugs are needed to treat infection with drug-resistant isolates. Here, we review the therapeutic armamentarium available to treat HIV-2-infected patients, as well as promising drugs in development. We also review HIV-2 drug resistance mutations and resistance pathways that develop in HIV-2-infected patients under treatment.

N-sulfonyl peptide-hybrids as a new class of dengue virus protease inhibitors

Dengue virus (DENV) from the Flaviviridae family causes an epidemic disease that seriously threatens human life. The viral serine protease NS2B-NS3 is a promising target for drug development against DENV and other flaviviruses. We here report the design, synthesis, and in-vitro characterization of potent peptidic inhibitors of DENV protease with a sulfonyl moiety as N-terminal cap, thereby creating sulfonamide-peptide hybrids. The in-vitro target affinities of some synthesized compounds were in the nanomolar range, with the most promising derivative reaching a K_i value of 78 nM against DENV-2 protease. The synthesized compounds did not have relevant off-target activity nor cytotoxicity. The metabolic stability of compounds against rat liver microsomes and pancreatic enzymes was remarkable. In general, the integration of sulfonamide moieties at the N-terminus of peptidic inhibitors proved to be a promising and attractive strategy for further drug development against DENV infections.

Strategies to improve the physicochemical properties of peptide-based drugs

Peptides are a rapid-growing class of therapeutics with unique and desirable physicochemical properties. Due to disadvantages such as low membrane permeability and susceptibility to proteolytic degradation, peptide-based drugs have limited bioavailability, a short half-life, and rapid in vivo elimination. Various strategies can be applied to improve the physicochemical properties of peptide-based drugs to overcome limitations such as limited tissue residence time, metabolic instability, and low permeability. Applied strategies including backbone modifications, side chain modifications, conjugation with polymers, modification of peptide termini, fusion to albumin, conjugation with the Fc portion of antibodies, cyclization, stapled peptides, pseudopeptides, cell-penetrating peptide conjugates, conjugation with lipids, and encapsulation in nanocarriers are discussed.

Assessing the potential of NS2B/NS3 protease inhibitors biomarker in curbing dengue virus infections: In silico vs. In vitro approach

An increase in the occurrence of viral infectious diseases is a global concern for human health. According to a WHO report, dengue virus (DENV) is one of the most common viral diseases affecting approximately 400 million people annually, with worsening symptoms in nearly 1% of cases. Both academic and industrial researchers have conducted numerous studies on viral epidemiology, virus structure and function, source and route of infection, treatment targets, vaccines, and drugs. The development of CYD-TDV or Dengvaxia^® vaccine has been a major milestone in dengue treatment. However, evidence has shown that vaccines have some drawbacks and limitations. Therefore, researchers are developing dengue antivirals to curb infections. DENV NS2B/NS3 protease is a DENV enzyme essential for replication and virus assembly, making it an interesting antiviral target. For faster hit and lead recognition of DENV targets, methods to screen large number of molecules at lower costs are essential. Similarly, an integrated and multidisciplinary approach involving in silico screening and confirmation of biological activity is required. In this review, we discuss recent strategies for searching for novel DENV NS2B/NS3 protease inhibitors from the in silico and in vitro perspectives, either by applying one of the approaches or by integrating both. Therefore, we hope that our review will encourage researchers to integrate the best strategies and encourage further developments in this area.

Development of novel S-N3-DABO derivatives as potent non-nucleoside reverse transcriptase inhibitors with improved potency and selectivity

Following on our initial discovery of S-CN-DABOs as non-nucleoside reverse transcriptase inhibitors (NNRTIs), a series of novel S-N₃-DABO derivatives F1-F31 were developed by substituting the cyano group of S-CN-DABOs with azide group. Some of these compounds were conferred significantly increased potency against wild-type HIV-1 and clinically observed mutant strains. Remarkably, the best compound F10 exerted a 7-fold improvement in potency (EC₅₀ = 0.053 μM) and 12.5-fold higher selectivity (SI = 6818) in MT-4 cells infected with wild-type HIV-1, compared to that of the parent compound B1 (EC₅₀ = 370 nM, SI = 547). The anti-HIV-1 activity of F10 against the tested mutant strains was prominently enhanced. For wild-type reverse transcriptase, it was approximately 19-fold more potent (IC₅₀ = 0.080 μM) than B1 (IC₅₀ = 1.51 μM). It was not found that this analog had significant inhibition of hERG, CYP, and acute toxicity after a single dose of F10 (1.0 g/kg).

Iron-catalyzed hydroarylation of 1,3-dienes with indoles

An efficient iron-catalyzed hydroarylation of 1,3-dienes with indoles has been developed for the first time.

Efficacy and safety clinical trial with efavirenz in patients diagnosed with adult Niemann-pick type C with cognitive impairment

BACKGROUND

Niemann-Pick disease Type C (NPC) is a genetic, incurable, neurodegenerative disorder. This orphan disease is most frequently caused by mutations in the NPC1 protein, resulting in intralysossomal cholesterol accumulation. NPC1 is found in neuronal cell bodies, axon terminals and synaptosomes, suggesting it plays a role in lysosomal degradation pathway and in synaptic transmission. Neuronal function is especially vulnerable to NPC1 deficiency and synaptic changes seem a key element in disease development. Currently, Miglustat (Zavesca®) is the only approved treatment for NPC. However, preclinical evidence showed that low-dose Efavirenz reverted synaptic defects through pharmacological activation of the enzyme CYP46.

METHODS

This is a single-center, phase II clinical trial to evaluate the efficacy and safety of Efavirenz in addition to standard of care in patients diagnosed with adult or late juvenile-onset NPC with cognitive impairment. All enrolled patients will be treated orally with 25 mg/d of Efavirenz for 52 weeks (1 year). Secondary objectives include evaluating clinical (neurological and neuropsychological questionnaires) and biological (imaging and biochemical biomarkers) parameters.

DISCUSSION

NPC is still an unmet medical need. Although different therapeutic approaches are under study, this is the first clinical trial (to the best of our knowledge) studying the effects of Efavirenz in adult- and late-juvenile-onset NPC. Despite the small sample size and the single-arm design, we expect the results to show Efavirenz's capacity of activating the CYP46 enzyme to compensate for NPC1 deficiency and correct synaptic changes, therefore compensating cognitive and psychiatric changes in these patients. This study may provide direct benefit to enrolled patients in terms of slowing down the disease progression.

Recent Patents and FDA-Approved Drugs Based on Antiviral Peptides and Other Peptide-Related Antivirals

In spite of existing cases of severe viral infections with a high mortality rate, there are not enough antiviral drugs and vaccines available for the prevention and treatment of such diseases. In addition, the increasing reports of the emergence of viral epidemics highlight, the need for novel molecules with antiviral potential. Antimicrobial peptides (AMPs) with antiviral activity or antiviral peptides (AVPs) have turned into a research hotspot and already show tremendous potential to become pharmaceutically available antiviral medicines. AMPs, a diverse group of bioactive peptides act as a part of our first line of defense against pathogen inactivation. Although most of the currently reported AMPs are either antibacterial or antifungal peptides, the number of antiviral peptides is gradually increasing. Some of the AMPs that are shown as effective antivirals have been deployed against viruses such as influenza A virus, severe acute respiratory syndrome coronavirus (SARS-CoV), HIV, HSV, West Nile Virus (WNV), and other viruses. This review offers an overview of AVPs that have been approved within the past few years and will set out a few of the most essential patents and their usage within the context mentioned above during 2000-2020. Moreover, the present study will explain some of the progress in antiviral drugs based on peptides and peptide-related antivirals.

5-Halogenation of Uridine Suppresses Protonation-Induced Tautomerization and Enhances Glycosidic Bond Stability of Protonated Uridine: Investigations via IRMPD Action Spectroscopy, ER-CID Experiments, and Theoretical Calculations

Uridine (Urd), a canonical nucleoside of RNA, is the most commonly modified nucleoside among those that occur naturally. Uridine has also been an important target for the development of modified nucleoside analogues for pharmaceutical applications. In this work, the effects of 5-halogenation of uracil on the structures and glycosidic bond stabilities of protonated uridine nucleoside analogues are examined using tandem mass spectrometry and computational methods. Infrared multiple photon dissociation (IRMPD) action spectroscopy experiments and theoretical calculations are performed to probe the structural influences of these modifications. Energy-resolved collision-induced dissociation experiments along with survival yield analyses are performed to probe glycosidic bond stability. The measured IRMPD spectra are compared to linear IR spectra predicted for the stable low-energy conformations of these species computed at the B3LYP/6-311+G(d,p) level of theory to determine the conformations experimentally populated. Spectral signatures in the IR fingerprint and hydrogen-stretching regions allow the 2,4-dihydroxy protonated tautomers (T) and O4- and O2-protonated conformers to be readily differentiated. Comparisons between the measured and predicted spectra indicate that parallel to findings for uridine, both T and O4-protonated conformers of the 5-halouridine nucleoside analogues are populated, whereas O2-protonated conformers are not. Variations in yields of the spectral signatures characteristic of the T and O4-protonated conformers indicate that the extent of protonation-induced tautomerization is suppressed as the size of the halogen substituent increases. Trends in the energy-dependence of the survival yield curves find that 5-halogenation strengthens the glycosidic bond and that the enhancement in stability increases with the size of the halogen substituent.

Do anti-HIV drugs pose a threat to photosynthetic microorganisms?

We investigated the occurrence and risk assessment of three anti-HIV drugs [(tenofovir (TNF), lamivudine (LMV) and efavirenz (EFV)] in urban rivers from Curitiba (Brazil), as well as the individual and combined effects of their environmental representative concentrations on the freshwater periphytic species Synechococcus elongatus (Cyanobacteria) and Chlorococcum infusionum (Chlorophyta). The three studied drugs, except TNF, were found in 100% of the samples, and concentrations in samples ranged from 165 to 412 ng TNF L^-1, 173-874 ng LMV L^-1 and 13-1250 ng EFV L^-1. Bioassays using artificial contaminated water showed that at environmental concentrations, TNF and LMV did not represent environmental risks to the studied photosynthetic organisms. However, EFV was shown to be toxic, affecting photosynthesis, respiration, and oxidative metabolism. The studied drugs demonstrated interactive effects. Indeed, when submitted to the combination of TNF and LMV, decreased photosynthesis was observed in C. infusionum cells. Moreover, the toxic effects of EFV were amplified in both species when TNF and/or LMV were added to the media. The simultaneous presence of TNF, LMV and EFV in environmental matrices associated with their interactive effects, lead to increased toxicological effects of water contaminated by anti-HIV drugs and thus to an ecological threat to photosynthetic microorganisms.

Beyond darunavir: recent development of next generation HIV-1 protease inhibitors to combat drug resistance

We report our recent development of a conceptually new generation of exceptionally potent non-peptidic HIV-1 protease inhibitors that displayed excellent pharmacological and drug-resistance profiles. Our X-ray structural studies of darunavir and other designed inhibitors from our laboratories led us to create a variety of inhibitors incorporating fused ring polycyclic ethers and aromatic heterocycles to promote hydrogen bonding interactions with the backbone atoms of HIV-1 protease as well as van der Waals interactions with residues in the S2 and S2' subsites. We have also incorporated specific functionalities to enhance van der Waals interactions in the S1 and S1' subsites. The combined effects of these structural templates are critical to the inhibitors' exceptional potency and drug-like properties. We highlight here our molecular design strategies to promote backbone hydrogen bonding interactions to combat drug-resistance and specific design of polycyclic ether templates to mimic peptide-like bonds in the HIV-1 protease active site. Our medicinal chemistry and drug development efforts led to the development of new generation inhibitors significantly improved over darunavir and displaying unprecedented antiviral activity against multidrug-resistant HIV-1 variants.

Ganoderma lucidum: Unutilized natural medicine and promising future solution to emerging diseases in Africa

Ganoderma lucidum is a well-known medicinal mushroom that has been used for the prevention and treatment of different ailments to enhance longevity and health specifically in China, Japan, and Korea. It was known as "God's herb" in ancient China as it was believed to prolong life, enhance the youthful spirit and sustain/preserve vitality. G. lucidum is seldom collected from nature and is substantially cultivated on wood logs and sawdust in plastic bags or bottles to meet the international market demand. Both in vitro and in vivo studies on the copious metabolic activities of G. lucidum have been carried out. Varied groups of chemical compounds including triterpenoids, polysaccharides, proteins, amino acids, nucleosides, alkaloids, steroids, lactones, lectins, fatty acids, and enzymes with potent pharmacological activities have been isolated from the mycelia and fruiting bodies of G. lucidum. Several researchers have reported the abundance and diversification of its biological actions triggered by these chemical compounds. Triterpenoids and polysaccharides of G. lucidum have been reported to possess cytotoxic, hepatoprotective, antihypertensive, hypocholesterolemic, antihistaminic effects, antioxidant, antimicrobial, anti-inflammatory, hypoglycemic antiallergic, neuroprotective, antitumor, immunomodulatory and antiangiogenic activities. Various formulations have been developed, patented, and utilized as nutraceuticals, cosmeceuticals, and pharmaceuticals from G. lucidum extracts and active compounds. Thus, this review presents current updates on emerging infectious diseases and highlights the scope, dynamics, and advances in infectious disease management with a particular focus on Ganoderma lucidum, an unutilized natural medicine as a promising future solution to emerging diseases in Africa. However, details such as the chemical compound and mode of action of each bioactive against different emerging diseases were not discussed in this study.

Mutation patterns, cross resistance and virological failure among HIV type-1 patients in Alexandria, Egypt

Aim: The main purpose of this cross-sectional study was to detect the prevalence of drug resistance mutations related to nonnucleoside/nucleoside reverse transcriptase inhibitors (NNRTIs/NRTIs) and protease inhibitors (PIs). Patients & methods: Patients (n = 45) with HIV type-1 were recruited, 30 of whom were treatment naive and 15 treatment experienced. A partial pol gene covering the protease/reverse transcriptase (PRRT) region was amplified and then sequenced by the Sanger method. Results & conclusion: The most common NNRTI/NRTI-related mutations were ‘V179I (24%) and K103N (14.3%)’ and ‘M41L and V75M’ (14.3% each). M36I and H69K were the most prevalent PI-related mutations (86% each). The results of the current study serve as an initial crucial step in defining the overall prevalence of HIV type-1 drug resistance in Egypt.

Role of medicinal plants in inhibiting SARS-CoV-2 and in the management of post-COVID-19 complications

BACKGROUND

The worldwide corona virus disease outbreak, generally known as COVID-19 pandemic outbreak resulted in a major health crisis globally. The morbidity and transmission modality of COVID-19 appear more severe and uncontrollable. The respiratory failure and following cardiovascular complications are the main pathophysiology of this deadly disease. Several therapeutic strategies are put forward for the development of safe and effective treatment against SARS-CoV-2 virus from the pharmacological view point but till date there are no specific treatment regimen developed for this viral infection.

PURPOSE

The present review emphasizes the role of herbs and herbs-derived secondary metabolites in inhibiting SARS-CoV-2 virus and also for the management of post-COVID-19 related complications. This approach will foster and ensure the safeguards of using medicinal plant resources to support the healthcare system. Plant-derived phytochemicals have already been reported to prevent the viral infection and to overcome the post-COVID complications like parkinsonism, kidney and heart failure, liver and lungs injury and mental problems. In this review, we explored mechanistic approaches of herbal medicines and their phytocomponenets as antiviral and post-COVID complications by modulating the immunological and inflammatory states.

STUDY DESIGN

Studies related to diagnosis and treatment guidelines issued for COVID-19 by different traditional system of medicine were included. The information was gathered from pharmacological or non-pharmacological interventions approaches. The gathered information sorted based on therapeutic application of herbs and their components against SARSCoV-2 and COVID-19 related complications.

METHODS

A systemic search of published literature was conducted from 2003 to 2021 using different literature database like Google Scholar, PubMed, Science Direct, Scopus and Web of Science to emphasize relevant articles on medicinal plants against SARS-CoV-2 viral infection and Post-COVID related complications.

RESULTS

Collected published literature from 2003 onwards yielded with total 625 articles, from more than 18 countries. Among these 625 articles, more than 95 medicinal plants and 25 active phytomolecules belong to 48 plant families. Reports on the therapeutic activity of the medicinal plants belong to the Lamiaceae family (11 reports), which was found to be maximum reported from 4 different countries including India, China, Australia, and Morocco. Other reports on the medicinal plant of Asteraceae (7 reports), Fabaceae (8 reports), Piperaceae (3 reports), Zingiberaceae (3 reports), Ranunculaceae (3 reports), Meliaceae (4 reports) were found, which can be explored for the development of safe and efficacious products targeting COVID-19.

CONCLUSION

Keeping in mind that the natural alternatives are in the priority for the management and prevention of the COVID-19, the present review may help to develop an alternative approach for the management of COVID-19 viral infection and post-COVID complications from a mechanistic point of view.

N-4 Alkyl Cytosine Derivatives Synthesis: A New Approach

The selective N-4 alkylation of cytosine plays a critical role in the synthesis of biologically active molecules. This work focuses on the development of practical reaction conditions toward a regioselective synthesis of N-4-alkyl cytosine derivatives. The sequence includes a direct and selective sulfonylation at the N-1 site of the cytosine, followed by the alkylation of the amino site using KHMDS in CH2Cl2/THF mixture, providing a fast and efficient approach consistent with pyrimidine-based drug design.

Hair Zidovudine Concentrations Predict Virologic Outcomes Among People Living with HIV/AIDS in China

BACKGROUND

Hair antiretroviral concentrations are an objective and non-invasive measure of adherence to long-term antiretroviral therapy (ART) and can further predict virologic outcomes among people living with HIV/AIDS (PLWH). Zidovudine, one of the mainstream antiretrovirals in China, has been verified to have high reliability in adherence assessment, especially for its hair concentrations. However, data are limited in its predicting virologic outcomes. Therefore, this study aimed to characterize whether hair zidovudine concentrations can predict virologic suppression among Chinese PLWH compared with hair lamivudine concentrations and two self-reported measures, the overall frequency of adherence behaviors and percentage adherence.

METHODS

This cross-sectional study randomly recruited 564 PLWH currently treated with zidovudine, lamivudine, and other ART agents (efavirenz, nevirapine, or lopinavir/ritonavir) in Guangxi, China. Hair antiretroviral concentrations were determined using the LC-ESI⁺-MS/MS method. Receiver operating characteristic (ROC) curves were used to estimate the optimal classification thresholds of hair concentrations of zidovudine and lamivudine, and the two self-reported measures. Based on those optimal classification thresholds, logistic regression was used to examine whether those four adherence measures can predict virologic suppression (HIV-1 RNA <200 copies/mL).

RESULTS

ROC curves demonstrated good classification performance for association with virologic suppression of zidovudine with the optimal threshold at 58 pg/mg and lamivudine at 255 pg/mg but no self-reported measures. PLWH with hair zidovudine concentrations >58 pg/mg had an adjusted odds ratio (aOR) of 43.191 (95% confidence interval (CI) = 10.171‒183.418, p < 0.001) for virologic suppression. Hair lamivudine concentrations were also associated with virologic suppression (aOR = 10.656, 95% CI = 3.670‒30.943, p < 0.001). However, two self-reported measures did not predict virologic suppression (aORs = 1.157 and 2.488, ps >0.149).

CONCLUSION

Hair zidovudine concentrations can be served as an alternative tool for clinically predicting virologic suppression among PLWH in China.

The emergence of severe acute respiratory syndrome-coronavirus 2 epidemic and pandemic

In the history of travel and tourism, a microscopic creature wrote a dark note, which interrupted the fast pace of globalization. In December 2019, in the seafood market of Wuhan city of China, a severe viral pneumonia-like infection was initiated, and which was new to the world and resulted in the emergence of a global health emergency. Thousands of passengers traveled through the city without knowing that one travel can change not only their lives but the future of the world. When WHO declared the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) outbreak as a global emergency, still no one thought of the conversion of the epidemic in the worst pandemic of the ongoing decade. Initially, the spread of SARS-CoV-2 infection over a wide area with a lot of patients at the same time declared it as a global epidemic, but the rapid escalation of the infection at more comprehensive geographical locations with a significant portion of the infected population soon turned the epidemic into the pandemic. The imported cases soon spread to their native places and turn the disease pandemic. While many countries are imposing partial or complete lockdown for the safety of travelers and civilians, the vacant human-made spaces and tourist architectures are asking that where the lacunae were, which has put the globe in such a devastating phase. The emergence of SARS-CoV-2 created a colossal health crisis for the entire world. From a provincial health concern to a global meltdown, the impact of SARS-CoV-2 has undeniably impacted the world medically, socially, financially, and psychologically. The footprints of SARS-CoV-2 are impactfully imprinted on the decade that will require a lot of time for global recovery.

Combining subsidiary and synchronous approaches for concurrent spectrofluorimetric assurance of lopinavir and ritonavir in tablets utilized in convention for treatment of coronavirus infection (COVID-19) and biological fluids

In this think about, assurance of lopinavir and ritonavir down to organic concentration level has been carried out. The assurance is based on expanding the selectivity of the spectrofluorimetric procedure by combining both subordinate and synchronous spectrofluorimetric approaches, which allow effective estimation of lopinavir at 248.8 nm and ritonavir at 300.1 nm within the nearness of each other at Δλ of 60 nm. Worldwide Conference on Harmonization approval rules were taken after to completely approve the strategy, and linearity was gotten for the two drugs over the extend of 0.4-2.4 µg mL^-1 for Lopinavir and 0.1-0.6 µg mL^-1 for ritonavir. Application of of the strategy was successfully carried out within the commercial tablets with great understanding with the comparison strategies. As the detection limits were down to 0.133 and 0.022 µg mL^-1 and quantitation limits were 0.395 and 0.068 µg mL^-1 for lopinavir and ritonavir, individually; the in vivo assurance of lopinavir and ritonavir in spiked plasma tests was pertinent. The rate recuperations in natural tests were 99.10 ± 0.77 and 99.54 ± 0.60 for lopinavir and ritonavir, individually. Water was utilized as the ideal weakening dissolvable within the proposed strategy which includes an eco-friendly justify.

Amphipathic Small Molecule AZT Compound Displays Potent Inhibitory Effects in Cancer Cell Proliferation

Cancer has been identified as a leading cause of death worldwide, and the increasing number of cancer cases threatens to shorten the average life expectancy of people. Recently, we reported a 3-azido-3-deoxythymidine (AZT)-based amphipathic small molecule, ADG-2e that revealed a notable potency against tumor metastasis. To evaluate the anticancer potential of ADG-2e, we assessed its anticancer potency in vitro and in vivo. Anticancer screening of ADG-2e against cervical cancer cells, HeLa CCL2, and BT549 mammary gland ductal carcinoma showed significant inhibition of cancer cell proliferation. Furthermore, mechanistic investigations revealed that cancer cell death presumably proceeded through an oncosis mechanistic pathway because ADG-2e treated cells showed severe damage on the plasma membrane, a loss of membrane integrity, and leakage of α-tubulin and β-actin. Finally, evaluation of the antitumorigenic potential of ADG-2e in mouse xenograft models revealed that this compound potentially inhibits cancer cell proliferation. Collectively, these findings suggest that ADG-2e can evolve as an anticancer agent, which may represent a model for nucleoside-based small molecule anticancer drug discovery.

Host Defence RNases as Antiviral Agents against Enveloped Single Stranded RNA Viruses

Owing to the recent outbreak of Coronavirus Disease of 2019 (COVID-19), it is urgent to develop effective and safe drugs to treat the present pandemic and prevent other viral infections that might come in the future. Proteins from our own innate immune system can serve as ideal sources of novel drug candidates thanks to their safety and immune regulation versatility. Some host defense RNases equipped with antiviral activity have been reported over time. Here, we try to summarize the currently available information on human RNases that can target viral pathogens, with special focus on enveloped single-stranded RNA (ssRNA) viruses. Overall, host RNases can fight viruses by a combined multifaceted strategy, including the enzymatic target of the viral genome, recognition of virus unique patterns, immune modulation, control of stress granule formation, and induction of autophagy/apoptosis pathways. The review also includes a detailed description of representative enveloped ssRNA viruses and their strategies to interact with the host and evade immune recognition. For comparative purposes, we also provide an exhaustive revision of the currently approved or experimental antiviral drugs. Finally, we sum up the current perspectives of drug development to achieve successful eradication of viral infections.

Simultaneous Determination of 6 Antiretroviral Drugs in Human Hair Using an LC-ESI+-MS/MS Method: Application to Adherence Assessment

BACKGROUND

The determination of antiretroviral drugs in hair is receiving considerable research interest to assess long-term adherence to antiretroviral therapy (ART). Currently in China, lamivudine, zidovudine, nevirapine, efavirenz, ritonavir, and lopinavir are combined as first-line and second-line free therapy regimens and are recommended for people living with HIV (PLWH). Simultaneous determination of the 6 antiretroviral drugs in human hair is important for accurately and widely assessing long-term adherence in Chinese PLWH receiving different ART regimens.

METHODS

Six drugs were extracted from 10-mg hair samples incubated in methanol for 16 hours at 37°C and then analyzed by liquid chromatography with tandem mass spectrometry using a mobile phase of 95% methanol, with an electrospray ionization source in multiple reaction monitoring and positive mode.

RESULTS

The LC-ESI+-MS/MS method exhibited a linear range (R2 > 0.99) within 6-5000, 10-5000, 6-50,000, 12-50,000, 8-5000, and 8-12,500 pg/mg for lamivudine, zidovudine, nevirapine, efavirenz, ritonavir, and lopinavir. For all 6 drugs, the limits of quantification ranged between 6 and 12 pg/mg. The intraday and interday coefficients of variation were within 15%, and the recoveries ranged from 91.1% to 113.7%. Furthermore, the other validation parameters (ie, selectivity, matrix effect, stability, and carryover) met the acceptance criteria stipulated by guidelines of the US Food and Drug Administration and European Medicines Agency. Significant intergroup differences were observed between high-adherence and low-adherence groups, with high intercorrelations in the hair content of the 6 drugs.

CONCLUSIONS

The developed method demonstrated good reliability, to comprehensively and accurately assess adherence in PLWH receiving different ART regimens.

Luminescent PLGA Nanoparticles for Delivery of Darunavir to the Brain and Inhibition of Matrix Metalloproteinase-9, a Relevant Therapeutic Target of HIV-Associated Neurological Disorders

Human immunodeficiency virus (HIV) can independently replicate in the central nervous system (CNS) causing neurocognitive impairment even in subjects with suppressed plasma viral load. The antiretroviral drug darunavir (DRV) has been approved for therapy of HIV-infected patients, but its efficacy in the treatment of HIV-associated neurological disorders (HAND) is limited due to the low penetration through the blood–brain barrier (BBB). Therefore, innovations in DRV formulations, based on its encapsulation in optically traceable nanoparticles (NPs), may improve its transport through the BBB, providing, at the same time, optical monitoring of drug delivery within the CNS. The aim of this study was to synthesize biodegradable polymeric NPs loaded with DRV and luminescent, nontoxic carbon dots (C-Dots) and investigate their ability to permeate through an artificial BBB and to inhibit in vitro matrix metalloproteinase-9 (MMP-9) that represents a factor responsible for the development of HIV-related neurological disorders. Biodegradable poly(lactic-co-glycolic) acid (PLGA)-based nanoformulations resulted characterized by an average hydrodynamic size less than 150 nm, relevant colloidal stability in aqueous medium, satisfactory drug encapsulation efficiency, and retained emitting optical properties in the visible region of the electromagnetic spectrum. The assay on the BBB artificial model showed that a larger amount of DRV was able to cross BBB when incorporated in the PLGA NPs and to exert an enhanced inhibition of matrix metalloproteinase-9 (MMP-9) expression levels with respect to free DRV. The overall results reveal the great potential of this class of nanovectors of DRV for an efficacious treatment of HANDs.

Update and latest advances in antiretroviral therapy

Since the first cases of AIDS appeared in 1981, human immunodeficiency virus type 1 (HIV-1) infection has reached pandemic proportions. Forty years later, research has led to the approval of more than 30 antiretroviral drugs, while combination therapies have turned HIV-1 infection into a chronic, but manageable disease. Still, drug toxicity and acquired and transmitted drug resistance remain as major threats to therapy success. In this review, we provide an overview on currently available anti-HIV drugs and the latest developments in antiretroviral therapy, focused on new antiretroviral agents acting on known and unexploited antiviral targets, prevention therapies aimed to improve available drug combinations, and research on new long-acting therapies, particularly those involving novel drug candidates such as lenacapavir or islatravir.

Effect of HIV aspartyl protease inhibitors on experimental infection with a cystogenic Me49 strain of Toxoplasma gondii

Toxoplasmosis is a zoonotic disease of major significant perspectives in public health and veterinary medicine. So far, the available drugs control only the active infection, once the parasite encysts in the tissues, they lose their efficacy. Cytokines; IFN-γ and IL-10, play a critical role in the modulation of toxoplasmic encephalitis and neuro-inflammation in chronic toxoplasmosis. Antiretroviral protease inhibitors applied in the treatment of acquired immunodeficiency syndrome, revealed activity against multiple parasites. Aluvia (lopinavir/ritonavir) (L/R); an aspartyl protease inhibitor, had efficiently treated T. gondii RH strain infection. We investigated the potential activity of L/R against experimental T. gondii infection with a cystogenic Me49 strain in mice, considering the role of IFN-γ and IL-10 in the neuropathology versus pyrimethamine-sulfadiazine combination therapy. Three aluvia regimens were applied; starting on the day of infection (acute phase), 2-week PI (early chronic phase) and eight weeks PI (late chronic phase). L/R reduced the brain-tissue cyst burden significantly in all treatment regimens. It impaired the parasite infectivity markedly in the late chronic phase. Ultrastructural changes were detected in Toxoplasma cyst membrane and wall, bradyzoite membrane and nuclear envelope. The signs of bradyzoite paraptosis and cytoplasmic lipid droplets were observed. L/R had significantly reduced the brain-homogenate levels of IFN-γ and IL-10 in its three regimens however, they could not reach the normal level in chronic phases. Cerebral hypercellularity, perivascular inflammatory response, lymphoplasmacytic infiltrates and glial cellular reaction were ameliorated by L/R treatment. Herein, L/R was proved to possess promising preventive and therapeutic perspectives in chronic cerebral toxoplasmosis.

Amino Acid and Peptide-Based Antiviral Agents

A significant number of antiviral agents used in clinical practice are amino acids, short peptides, or peptidomimetics. Among them, several HIV protease inhibitors (e. g. lopinavir, atazanavir), HCV protease inhibitors (e. g. grazoprevir, glecaprevir), and HCV NS5A protein inhibitors have contributed to a significant decrease in mortality from AIDS and hepatitis. However, there is an ongoing need for the discovery of new antiviral agents and the development of existing drugs; amino acids, both proteinogenic and non-proteinogenic in nature, serve as convenient building blocks for this purpose. The synthesis of non-proteinogenic amino acid components of antiviral agents could be challenging due to the need for enantiomerically or diastereomerically pure products. Herein, we present a concise review of antiviral agents whose structures are based on amino acids of both natural and unnatural origin. Special attention is paid to the synthetic aspects of non-proteinogenic amino acid components of those agents.

Current status and future prospects of drug-target interaction prediction

Drug-target interaction prediction is important for drug development and drug repurposing. Many computational methods have been proposed for drug-target interaction prediction due to their potential to the time and cost reduction. In this review, we introduce the molecular docking and machine learning-based methods, which have been widely applied to drug-target interaction prediction. Particularly, machine learning-based methods are divided into different types according to the data processing form and task type. For each type of method, we provide a specific description and propose some solutions to improve its capability. The knowledge of heterogeneous network and learning to rank are also summarized in this review. As far as we know, this is the first comprehensive review that summarizes the knowledge of heterogeneous network and learning to rank in the drug-target interaction prediction. Moreover, we propose three aspects that can be explored in depth for future research.

Acetylenic Replacement of Albicidin's Methacrylamide Residue Circumvents Detrimental E/Z Photoisomerization and Preserves Antibacterial Activity

The natural product albicidin is a highly potent inhibitor of bacterial DNA gyrase. Its outstanding activity, particularly against Gram-negative pathogens, qualifies it as a promising lead structure in the search for new antibacterial drugs. However, as we show here, the N-terminal cinnamoyl moiety of albicidin is susceptible to photochemical E/Z isomerization. Moreover, the newly formed Z isomer exhibits significantly reduced antibacterial activity, which hampers the development and biological evaluation of albicidin and potent derivatives thereof. Hence, we synthesized 13 different variants of albicidin in which the vulnerable para-coumaric acid moiety was replaced; this yielded photostable analogues. Biological activity assays revealed that diaryl alkyne analogues exhibited virtually undiminished antibacterial efficacy. This promising scaffold will therefore serve as a blueprint for the design of a potent albicidin-based drug.

Nanotechnology-based antiviral therapeutics

The host immune system is highly compromised in case of viral infections and relapses are very common. The capacity of the virus to destroy the host cell by liberating its own DNA or RNA and replicating inside the host cell poses challenges in the development of antiviral therapeutics. In recent years, many new technologies have been explored for diagnosis, prevention, and treatment of viral infections. Nanotechnology has emerged as one of the most promising technologies on account of its ability to deal with viral diseases in an effective manner, addressing the limitations of traditional antiviral medicines. It has not only helped us to overcome problems related to solubility and toxicity of drugs, but also imparted unique properties to drugs, which in turn has increased their potency and selectivity toward viral cells against the host cells. The initial part of the paper focuses on some important proteins of influenza, Ebola, HIV, herpes, Zika, dengue, and corona virus and those of the host cells important for their entry and replication into the host cells. This is followed by different types of nanomaterials which have served as delivery vehicles for the antiviral drugs. It includes various lipid-based, polymer-based, lipid-polymer hybrid-based, carbon-based, inorganic metal-based, surface-modified, and stimuli-sensitive nanomaterials and their application in antiviral therapeutics. The authors also highlight newer promising treatment approaches like nanotraps, nanorobots, nanobubbles, nanofibers, nanodiamonds, nanovaccines, and mathematical modeling for the future. The paper has been updated with the recent developments in nanotechnology-based approaches in view of the ongoing pandemic of COVID-19.Graphical abstract.

New Approaches and Repurposed Antiviral Drugs for the Treatment of the SARS-CoV-2 Infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus that causes coronavirus disease 2019 (COVID-19). The outbreak of this coronavirus was first identified in Wuhan (Hubei, China) in December 2019, and it was declared as pandemic by the World Health Organization (WHO) in March 2020. Today, several vaccines against SARS-CoV-2 have been approved, and some neutralizing monoclonal antibodies are being tested as therapeutic approaches for COVID-19 but, one of the key questions is whether both vaccines and monoclonal antibodies could be effective against infections by new SARS-CoV-2 variants. Nevertheless, there are currently more than 1000 ongoing clinical trials focusing on the use and effectiveness of antiviral drugs as a possible therapeutic treatment. Among the classes of antiviral drugs are included 3CL protein inhibitors, RNA synthesis inhibitors and other small molecule drugs which target the ability of SARS-COV-2 to interact with host cells. Considering the need to find specific treatment to prevent the emergent outbreak, the aim of this review is to explain how some repurposed antiviral drugs, indicated for the treatment of other viral infections, could be potential candidates for the treatment of COVID-19.

Secondary hypertriglyceridemia

Secondary hypertriglyceridemia (HTG) are the most common cause of excess triglyceride rich particles in plasma. Faced with HTG, the first thing to do is rule out if there is a secondary cause since it can interact with genetic susceptibility and further aggravate the HTG. The most common causes are diet with high fat and high glycemic index, obesity, diabetes mellitus, alcohol consumption, renal disease like nephrotic syndrome, hepatic disorders and medications. The most important medications that can influence in HTG are oestrogen, isotretinoin, immunosuppressant therapy, L-asparaginase and with less effect thiazides, beta blockers, atypical antipsychotics and glucocorticoids. Other causes less frequent are endocrinological diseases such as Cushing's syndrome, acromegaly, hypothyroidism; pregnancy, lipodystrophies and autoimmune diseases. Lastly, the identifications and treatment or correction of secondary causes is a corner stone in the treatment of this disease.

Association of Hair Concentrations of Antiretrovirals with Virologic Outcomes Among People Living with HIV in Guangxi, China

BACKGROUND

Hair concentrations of antiretrovirals are an innovative and non-invasive method for measuring cumulative antiretroviral exposure and assessing long-term antiretroviral adherence. This study aimed to examine hair concentrations of antiretrovirals in relation to virologic outcomes among PLHIV in Guangxi, China.

METHODS

Cross-sectional data of hair concentrations of antiretrovirals and HIV viral load were collected from 215 PLHIV in Guangxi, China. Multivariate logistic regression analyses were used to examine the association of hair concentrations of antiretrovirals with virologic outcomes.

RESULTS

Of the 215 participants, 215, 67, and 163 PLHIV are receiving lamivudine, zidovudine, and efavirenz, respectively. Multivariate analysis revealed that hair concentrations of lamivudine [odds ratio = 16.52, 95% CI 2.51-108.60, p = 0.004] and efavirenz [odds ratio = 14.26, 95% CI 1.18-172.01, p = 0.036], but not zidovudine [odds ratio = 1.77, 95% CI 0.06-56.14, p = 0.747], were the strongest independent predictor of virologic suppression when controlling for sociodemographic and other HIV-related characteristics.

CONCLUSION

Hair concentrations of lamivudine and efavirenz were the strongest independent predictor of virologic suppression among Chinese PLHIV. Hair analysis of antiretrovirals may provide a non-invasive, cost-effective tool that predicts virologic suppression among PLHIV in China.

Di-tert-butyl Phosphonate Route to the Antiviral Drug Tenofovir

Di-tert-butyl oxymethyl phosphonates were investigated regarding their suitability for preparing the active pharmaceutical ingredient tenofovir (PMPA). First, an efficient and simple access to the crystalline di-tert-butyl(hydroxymethyl)phosphonate was developed. O-Mesylation gave high yields of the active phosphonomethylation reagent. For the synthesis of tenofovir, a two-step sequence was developed using Mg(OtBu)2 as the base for the alkylation of (R)-9-(2-hydroxypropyl)adenine. Subsequent deprotection could be achieved with aqueous acids. (Di-tert-butoxyphosphoryl)methyl methanesulfonate showed to be the most efficient electrophile tested, affording PMPA in 72% yield on a 5 g scale. The developed protocol could also be applied for the preparation of the hepatitis B drug adefovir (64% yield/1 g scale).

Drugs intervention study in COVID-19 management

By 9 February 2021, the Coronavirus has killed 2,336,650 people worldwide and it has been predicted that this number continues to increase in year 2021. The study aimed to identify therapeutic approaches and drugs that can potentially be used as interventions in Coronavirus 2019 (COVID-19) management. A systematic scoping review was conducted. Articles reporting clinical evidence of therapeutic management of COVID-19 were selected from three different research databases (Google Scholar, PubMed, and Science Direct). From the database search, 31 articles were selected based on the study inclusion and exclusion criteria. This review paper showed that remdesivir and ivermectin significantly reduced viral ribonucleic acid (RNA) activity. On the other hand, convalescent plasma (CP) significantly improved COVID-19 clinical symptoms. Additionally, the use of corticosteroid increased survival rates in COVID-19 patients with acute respiratory distress syndrome (ARDS). Findings also indicated that both hydroxychloroquine and favipiravir were effective against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, lopinavir-ritonavir combination was not effective against COVID-19. Finally, ribavirin, galidesivir, and sofosbuvir showed potential therapeutic benefit in treating COVID-19, but there is a lack of clinical evidence on their effectiveness against SARS-CoV-2. Remdesivir, ivermectin, favipiravir, hydroxychloroquine, dexamethasone, methylprednisolone, and CP are the therapeutic agents that can potentially be used in COVID-19 management.