Protein therapeutics are extensively used in the treatment of autoimmune diseases, but a subset of patients appears to be refractory to these treatments, mainly due to the development of an immune response to the drug. A better understanding of the mechanism underlying the therapeutic drug’s failure becomes fundamental for the development of new and more effective treatments. Unfortunately, there are few cases where the exact mechanisms through which drugs bypass immunological tolerance and provoke immunogenicity have been studied. In this context, peptide epitope identification gained increasing importance in investigating the molecular mechanism of therapeutic drug’s immune responses. Despite peptide identification and use to monitor anti-drug antibody (ADA) profiles is a promising research field, their use is far away from a wide application both at the research and at the commercial level. Herein it is reported a compilation of studies in which peptides are directly involved in anti-drug immune responses, becoming the molecular key step for a better understanding of refractory reactions in therapeutic drugs. An overview on T-cell and B-cell peptide recognition is given, showing the growing potential and advantages of peptides when used in the field of refractoriness to drugs. This review includes studies describing antigenic peptides that enable enhanced ADA detection directly in patients’ sera, as well as the proof of concept that asses the use of peptides instead of proteins, to facilitate the identification of neutralizing ADA.

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in December 2019 quickly escalated to pandemic levels and had a severe impact on public health. There are 761 million confirmed coronavirus disease 2019 (COVID-19) cases, with over 6.88 million deaths worldwide till March 2023. Severe cases of the disease caused critical respiratory failure followed by multiorgan involvement. Clinical escalation of COVID-19 has been correlated with markedly increased plasma inflammatory markers [e.g., C-reactive protein (CRP)] and pro-inflammatory cytokine levels [e.g., interleukin (IL)-6, tumor necrosis factor-α (TNF-α)]. Therapeutic options have mostly utilized corticosteroids, antivirals (e.g., remdesivir), and monoclonal antibody-based immunomodulation (e.g., tocilizumab). These existing treatments have adverse side effects, inadequate efficacy, and limitations in administering to patients with comorbidities and other underlying diseases. Monoclonal antibody-based therapies and some of the antivirals are very costly. Many phytochemicals have previously reported anti-inflammatory, antiviral, and antioxidant properties. Studying the effectiveness of such phytochemicals against COVID-19 and identifying new plant-derived molecules with antiviral properties have been a focus since the SARS-CoV-2 outbreak. This review article has documented in vitro, in vivo, and clinical studies encompassing 28 different phytochemicals belonging to various chemical groups (e.g., polyphenols, alkaloids, terpenes) that show anti-COVID-19 activity. These findings suggest that multiple phytochemicals can interfere with virus entry and replication inside the host cell. Many of them can protect from cytokine storm by acting on intracellular signalling pathways in addition to inhibiting virus multiplication. Phytochemicals may prove useful in alleviating post-COVID complications associated with kidney injury, and central nervous system complications, as well. Plant-derived compounds are usually cheaper and have fewer side effects. But, developing new formulations with better absorption and bioavailability remains a priority. This review informs the readers of the current status and indicates the ongoing research in this highly relevant field.

Green propolis is collected by Apis mellifera from the flowers and buds of Baccharis dracunculifolia. It has several chemical compounds that confer anti-inflammatory, antimicrobial, healing, and antioxidant biological activities. To report a series of clinical cases in the treatment of oral mucositis (OM) in patients with cancer undergoing radiotherapy in the head and neck region. Rapid treatment of OM means restoring quality of life to patients and lowering the cost of cancer treatment for public health. There male patients with oral carcinoma undergoing radiotherapy treatment were followed between August 2018 and April 2019. The patients presented themselves to the clinics in the Faculty of Dentistry of Federal University of Minas Gerais with erythematous and ulcerated coalescing lesions with purulent fibrin pseudomembranes in the oral mucosa, classified as grade IV OM according to the World Health Organization. The patients complained about the inability to eat, drink, and speak, which caused the radiotherapy interruption. After completing the clinical forms, anamnesis, and proper oral hygiene of each patient, a mucoadherent gel containing 5% propolis was prescribed for daily use, with a 3 time-a-day application every 8 h. After 7 days of use, there was an 80% lesion reduction, with total remission after 15 days of its application. The rapid response with total remission of lesions seems to be related to the chemical composition of propolis. Clinical and cellphone monitoring of patients, weekly and daily, respectively, were essential for successful treatment. The patients were monitored for one year, being encouraged to make constant use of the gel to control hyposalivation caused by changes in the salivary glands during radiotherapy.

Thrombocytopenia is one of the most frequent implications of liver cirrhosis. This condition, when present in the severe form [platelet count (PLT) less than 50 × 10⁹/L] correlates, with an increased risk of bleeding during the main diagnostic-therapeutic procedures which cirrhotic patients usually undergone. In these cases, generally, an infusion of platelets is performed, albeit in recent years has been replaced by a cycle of second generation thrombopoietin receptor (TpoR) agonists. This article reports two different cases concerning respectively an 83-year-old female patient suffering from arterial hypertension, aneurysm of the sub-renal aorta, hepatitis C virus (HCV)-positive liver cirrhosis responsive to treatment with antiviral drugs, and a 2.0 cm diameter hepatocellular carcinoma (HCC) nodule localized in the hepatic segment III and a 53-year-old female patient with HCV-positive liver cirrhosis complicated by portal hypertension with splenomegaly, thrombocytopenia, and F3 esophageal varices at high risk of bleeding. Both of them, eligible for invasive procedures such as HCC transarterial chemoembolization (TACE) and for esophageal variceal band ligation, were prescribed prophylaxis with TpoR agonists due to their severe and persistent thrombocytopenia. These two cases show how a short course of lusutrombopag allows to safely perform one or more invasive procedures and how the administration of the drug can be repeated without losing efficacy. Furthermore, this drug shows an excellent safety profile and avoids the risks of platelet transfusion. In conclusion, second generation TpoR agonists can be considered the prophylactic treatment of choice to reduce the risk of bleeding in patients with liver cirrhosis and severe thrombocytopenia.

Flavonoids present a large group of natural polyphenols with numerous important health benefits for preventing and treating a diverse variety of pathological conditions. However, the actual therapeutic use of these phytochemicals is impeded by their low oral bioavailability. In this commentary article, an interesting paradox is presented: while the ingested flavonoid glycosides can be absorbed by means of sodium-dependent glucose transporters (SGLTs; SGLT1) located in the brush border membrane facing the lumen of the small intestine, certain flavonoid aglycones are able to inhibit these shuttle proteins. It is expected that avoiding the co-intake of such SGLT1 inhibitors concomitantly with flavonoid-rich foods might provide a new option for enhancing the oral bioavailability of flavonoids, thereby preventing the transport of unabsorbed compounds to the large intestine and conversion into catabolites by the colonic microbiota. Altogether, the administration of flavonoids in appropriate combinations is highlighted for getting the maximal health benefits from consuming these bioactive compounds.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), known to cause the coronavirus disease 2019 (COVID-19), was declared a pandemic in early 2020. During the past time, several infections control methods have been developed. Nevertheless, all of them have certain limitations: uncertainty in duration, limited efficacy of vaccines, and lack of effective drugs for COVID-19 treatment. So, the issue of creating drugs for symptomatic and etiotropic therapy is still relevant. This review summarizes the current knowledge of using natural compounds as anti-SARS-CoV-2 agents by analysing the results of in vitro studies and completed clinical trials (CTs). Also, this work highlighted the most active molecules and discussed the possibility of using some compounds in clinical practice.

Nonalcoholic fatty liver disease (NAFLD), its more rapidly progressive steatohepatitic variant [nonalcoholic steatohepatitis, (NASH)], and the recently defined metabolic dysfunction-associated fatty liver disease (MAFLD) may be collectively alluded to as “metabolic fatty liver syndromes” (MFLS). MFLS is a common clinical complaint for which no licensed drug treatment is available and a public health issue posing a heaven burden on healthcare systems. Iron plays a key role in many of the key pathogenic steps concurring in the development and progression of MFLS, notably including genetics, intestinal dysbiosis, adipositis, insulin resistance, metaflammation, oxidative stress and ferroptosis, endoplasmic reticulum stress, and hepatic fibrosis. This notion raises the logical expectation that iron depletion, which can easily be implemented with venesection, might improve several aspects of MFLS. However, few published studies have globally failed to support these expectations. In conclusion, venesection in MFLS exhibits a strong biological rationale and possible metabolic benefits. However, confronted with failures in hepato-histological outcomes, data call for additional studies aimed to reconcile these inconsistencies.

Despite recent advancements in the field of neuro-ophthalmology, the rising rates of neurological and ophthalmological conditions, mismatches between supply and demand of clinicians, and an aging population underscore the urgent need to explore new therapeutic approaches within the field. Glucagon-like peptide 1 receptor agonists (GLP-1RAs), traditionally used in the treatment of type 2 diabetes, are becoming increasingly appreciated for their diverse applications. Recently, GLP-1RAs have been approved for the treatment of obesity and recognized for their cardioprotective effects. Emerging evidence indicates some GLP-1RAs can cross the blood-brain barrier and may have neuroprotective effects. Therefore, this article aims to review the literature on the neurologic and neuro-ophthalmic role of glucagon-like peptide 1 (GLP-1). This article describes GLP-1 peptide characteristics and the mechanisms mediating its known role in increasing insulin, decreasing glucagon, delaying gastric emptying, and promoting satiety. This article identifies the sources and targets of GLP-1 in the brain and review the mechanisms which mediate its neuroprotective effects, as well as implications for Alzheimer’s disease (AD) and Parkinson’s disease (PD). Furthermore, the preclinical works which unravel the effects of GLP-1 in ocular dynamics and the preclinical literature regarding GLP-1RA use in the management of several neuro-ophthalmic conditions, including diabetic retinopathy (DR), glaucoma, and idiopathic intracranial hypertension (IIH) are discussed.

Bacterial infections constitute one of the major cases of primary medical incidences worldwide. Historically, the fight against bacterial infections in humans has been an ongoing battle, due to the ability of bacteria to adapt and to survive. Indeed, bacteria have developed various mechanisms of resistance against several therapeutic agents. Consequently, the scientific community is always interested in search of new therapeutic agents, which are able to efficiently kill resistant-bacterial strains. This article covers the most recent antibacterial molecules approved by the Food and Drugs Administration (FDA) and European Medicines Agency (EMA) from 2012 to 2022 and intends to focus on synthetic derivatives to give a pedagogical view, with the goal of highlighting the importance of organic synthesis to obtain greater efficacy. A focus will be made on studies describing the structure and activity of the organic molecules and their interactions with their respective biological targets.

Peptides constitute an important component of Nature’s pharmacy and they play a significant role in several signaling pathways acting as natural biological messengers. While nature has mastered the cycle of creation, application, and destruction of large and short peptides to the benefit of the host organism, organic and medicinal chemists have in their capacity and small steps, made big developments in the field of peptide synthesis as well as in developing them as therapeutics. In comparison to their big counterparts, i.e. proteins, short peptides encompass several advantages, from the ease of synthesis to their physico-chemical properties. However, the real challenge for in vivo application of therapeutic peptides is to overcome their low plasma availability and their fast enzymatic degradation. This review briefly covers the relevant areas of medicinally important short peptides and the recent developments made to turn these peptides into therapeutics. Also presented in this article are important efforts and strategies used to overcome some of the inherent limitations of peptidic molecules and thereby facilitate their progression in the clinical phases towards approved drugs.

Malignant brain tumors are the leading cause of cancer-related death in children and remain a significant cause of morbidity and mortality throughout all demographics. Central nervous system (CNS) tumors are classically treated with surgical resection and radiotherapy in addition to adjuvant chemotherapy. However, the therapeutic efficacy of chemotherapeutic agents is limited due to the blood-brain barrier (BBB). Magnetic resonance guided focused ultrasound (MRgFUS) is a new and promising intervention for CNS tumors, which has shown success in preclinical trials. High-intensity focused ultrasound (HIFU) has the capacity to serve as a direct therapeutic agent in the form of thermoablation and mechanical destruction of the tumor. Low-intensity focused ultrasound (LIFU) has been shown to disrupt the BBB and enhance the uptake of therapeutic agents in the brain and CNS. The authors present a review of MRgFUS in the treatment of CNS tumors. This treatment method has shown promising results in preclinical trials including minimal adverse effects, increased infiltration of the therapeutic agents into the CNS, decreased tumor progression, and improved survival rates.

Bladder cancer (BC) is a complex disease with multiple clinical manifestations and treatment challenges, and current standard-of-care therapies remain limited and unfavorable. Theranostics, the integration of diagnostic and therapeutic technologies, has emerged as a promising strategy to address these challenges. The rapid development of nanomedicine has been a source of hope for the improvement of BC therapies and diagnostics by reducing side effects, enhancing tumor suppression, and overcoming drug resistance. Metal nanoparticles (NPs), inorganic NPs, polymer NPs, etc. have their respective advantages and show encouraging potential in the therapy of BC. In this review, we provide an overview on the state of the art in nanotechnology-based theranostics for BC, offering insights into the design and discovery of novel NPs for future BC management.

It is widely acknowledged that sialyl Lewis X (sLeX), the composition and linkage of which are N-acetylneuraminic acid (Neu5Ac) α2-3 galactose (Gal) β1-4 [fucose (Fuc) α1-3] N-acetylglucosamine, is usually attached to the cell surface. It presents as a terminal structure on either glycoproteins or glycolipids and has been demonstrated to be related to various biological processes, such as fertilization and selectin binding. Due to the vital role of sLeX, its synthesis as well as its determination approaches have attracted considerable attention from many researchers. In this review, the focus is sLeX on glycoproteins. The biological importance of sLeX in fertilization and development, immunity, cancers, and other aspects will be first introduced. Then the chemical and enzymatic synthesis of sLeX including the contributions from more than 15 international research groups will be described, followed by a brief view of the sLeX detection focusing on monosaccharides and linkages. This review is valuable for those readers who are interested in the chemistry and biology of sLeX.