Chrono-pharmaceutical approaches to optimize dosing regimens based on the circadian clock machinery

Daily rhythmic variations in biological functions affect the efficacy and/or toxicity of drugs: a large number of drugs cannot be expected to exhibit the same potency at different administration times. The “circadian clock” is an endogenous timing system that broadly regulates metabolism, physiology and behavior. In mammals, this clock governs the oscillatory expression of the majority of genes with a period length of approximately 24 h. Genetic studies have revealed that molecular components of the circadian clock regulate the expression of genes responsible for the sensitivity to drugs and their disposition. The circadian control of pharmacodynamics and pharmacokinetics enables ‘chrono-pharmaceutical’ applications, namely drug administration at appropriate times of day to optimize the therapeutic index (efficacy vs. toxicity). On the other hand, a variety of pathological conditions also exhibit marked day-night changes in symptom intensity. Currently, novel therapeutic approaches are facilitated by the development of chemical compound targeted to key proteins that cause circadian exacerbation of disease events. This review presents an overview of the current understanding of the role of the circadian biological clock in regulating drug efficacy and disease conditions, and also describes the importance of identifying the difference in the circadian machinery between diurnal and nocturnal animals to select the most appropriate times of day to administer drugs in humans.

Comprehensive analyses of the inotropic compound omecamtiv mecarbil in rat and human cardiac preparations

Omecamtiv mecarbil (OM), a myosin activator, was reported to induce complex concentration- and species-dependent effects on contractile function and clinical studies indicated a low therapeutic index with diastolic dysfunction at concentrations above 1 µM. To further characterize effects of OM in a human context and under different preload conditions, we constructed a setup that allows isometric contractility analyses of human induced pluripotent stem cell (hiPSC)-derived engineered heart tissues (EHTs). The results were compared to effects of OM on the very same EHTs measured under auxotonic conditions. OM induced a sustained, concentration-dependent increase in time-to-peak under all conditions (maximally 2-3 fold). Peak force, in contrast, was increased by OM only in human, but not rat EHTs and only under isometric conditions, varied between hiPSC lines and showed a biphasic concentration-dependency with maximal effects at 1 µM. Relaxation time tended to fall under auxotonic and strongly increase under isometric conditions, again with biphasic concentration-dependency. Diastolic tension concentration-dependently increased under all conditions. The latter was reduced by an inhibitor of the mitochondrial sodium calcium exchanger (CGP-37157). OM induced increases in mitochondrial oxidation in isolated cardiomyocytes, indicating that OM, an inotrope that does not increase intracellular and mitochondrial Ca2+, can induce mismatch between an increase in ATP and ROS production and unstimulated mitochondrial redox capacity. Taken together, we developed a novel setup well suitable for isometric measurements of EHTs. The effects of OM on contractility and diastolic tension are complex with concentration-, time-, species- and loading-dependent differences. Effects on mitochondrial function require further studies.

The Triprenylated Anthranoid Ferruginin A, a Promising Scaffold for the Development of Novel Antibiotics against Gram-Positive Bacteria

In today’s post-antibiotic era, the search for new antimicrobial compounds is of major importance and nature represents one of the primary sources of bioactive molecules. In this work, through a cheminformatics approach, we clustered an in-house library of natural products and their derivatives based on a combination of fingerprints and substructure search. We identified the prenylated emodine-type anthranoid ferruginin A as a novel antimicrobial compound. We tested its ability to inhibit and kill a panel of Gram-positive and Gram-negative bacteria, and compared its activity with that of two analogues, vismione B and ferruanthrone. Furthermore, the capability of these three anthranoids to disrupt staphylococcal biofilm was investigated, as well as their effect on the viability of human keratinocytes. Ferruginin A showed a potent activity against both the planktonic and biofilm forms of Gram-positive bacteria (i.e., Staphylococcus aureus and S. epidermidis) and had the best therapeutic index compared to vismione B and ferruanthrone. In conclusion, ferruginin A represents a promising scaffold for the further development of valuable antimicrobial agents.

Bioanalysis of aminoglycosides using high-performance liquid chromatography

Aminoglycosides are broad-spectrum antibiotics used in the treatment of gram-negative bacterial infections. Due to their nephrotoxic and ototoxic potential (narrow therapeutic index), the use of aminoglycoside for clinical indications requires monitoring. The objective of this review was to identify relevant literature reporting liquid chromatographic methods for the bioanalysis of aminoglycosides in both preclinical and clinical settings/experiments. Data on liquid chromatographic methods were collected from articles in an online academic database (PubMed, Science Direct, Scopus, and Google Scholar). All 71 articles published from 1977 to 2020 were included in the review. Reversed-phase liquid chromatography was the most used method for the bioanalysis of aminoglycosides. Fluorescence or ultraviolet detection methods were mostly used from 1977 to 2002 (51 articles), while mass spectrometry was predominantly used as a detector from 2003 to 2020 (15 articles). Sixty-seven articles reported calibration ranges, which varied significantly for the various drugs assayed: some in the range of 0.1-0.5 ng/mL and others 1250-200000 ng/mL. Also, 61 articles reported R2 values (0.964-1.0) for almost all analytes under consideration. Sixty-three articles reported percent recoveries mostly between 61.0 % to 114.0 %, with only two articles reporting recoveries of 4.9 % and 36 %. Out of the 71 reviewed articles, 56 reported intermediate precision values ranging between 0.331 % to 19.76 %, which is within the acceptable limit of 20 %. This review will serve as a guide for research and/or routine clinical monitoring of aminoglycosides in biological matrices.

Soluble Expression of a Neo2/15-Conjugated Single Chain Fv against PD-L1 in Escherichia coli

Immunocytokines, antibody-cytokine fusion proteins, have the potential to improve the therapeutic index of cytokines by delivering the cytokine to the site of localized tumor cells using antibodies. In this study, we produced a recombinant anti-programmed death-ligand 1 (PD-L1) scFv, an antibody fragment against PD-L1 combined with a Neo2/15, which is an engineered interleukin with superior function using an E. coli expression system. We expressed the fusion protein in a soluble form and purified it, resulting in high yield and purity. The high PD-L1-binding efficiency of the fusion protein was confirmed via enzyme-linked immunosorbent assay, suggesting the application of this immunocytokine as a cancer-related therapeutic agent.

Monoclonal antibodies and their target specificity against SARS-CoV-2 infections: Perspectives and challenges Short title: Monoclonal antibodies and SARS-CoV-2 infections

The world continues to be in the midst of a distressing pandemic of coronavirus disease 2019 (COVID-19) infection caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a novel virus with multiple antigenic systems. The virus enters via nasopharynx, oral and infects cells by the expression of the spike protein, and enters the lungs using the angiotensin-converting enzyme-2 receptor. The spectrum of specific immune responses to SARS-CoV-2 virus infection is increasingly challenging as frequent mutations have been reported and their antigen specificity varies accordingly. The development of monoclonal antibodies (mAbs) will have a more significant advantage in suppressing SARS-CoV-2 virus infectivity. Recently, mAbs have been developed to target specific neutralizing antibodies against SARS-CoV-2 infection. The use of the therapeutic index of mAbs that can elicit neutralization by binding to the viral spike protein and suppress the cytokine network is a classic therapeutic approach for a potential cure. The development of mAbs against B-cell function as well as inhibition of the cytokine network has also been a focus in recent research. Recent studies have demonstrated the efficacy of mAbs as antibody cocktail preparations against SARS-CoV-2 infection. Target specific therapeutic accomplishment with mAbs, a milestone in the modern therapeutic age, can be used to achieve a specific therapeutic strategy to suppress SARS-CoV-2 virus infection. This review focuses on the molecular aspects of the cytokine network and antibody formation to better understand the development of mAbs against SARS-CoV-2 infection.

Discovery of a novel antibacterial protein CB6-C to target methicillin-resistant Staphylococcus aureus

Given a serious threat of multidrug-resistant bacterial pathogens to global healthcare, there is an urgent need to find effective antibacterial compounds to treat drug-resistant bacterial infections. In our previous studies, Bacillus velezensis CB6 with broad-spectrum antibacterial activity was obtained from the soil of Changbaishan, China. In this study, with methicillin-resistant Staphylococcus aureus as an indicator bacterium, an antibacterial protein was purified by ammonium sulfate precipitation, Sephadex G-75 column, QAE-Sephadex A 25 column and RP-HPLC, which demonstrated a molecular weight of 31.405 kDa by SDS-PAGE. LC–MS/MS analysis indicated that the compound was an antibacterial protein CB6-C, which had 88.5% identity with chitosanase (Csn) produced by Bacillus subtilis 168. An antibacterial protein CB6-C showed an effective antimicrobial activity against gram-positive bacteria (in particular, the MIC for MRSA was 16 μg/mL), low toxicity, thermostability, stability in different organic reagents and pH values, and an additive effect with conventionally used antibiotics. Mechanistic studies showed that an antibacterial protein CB6-C exerted anti-MRSA activity through destruction of lipoteichoic acid (LTA) on the cell wall. In addition, an antibacterial protein CB6-C was efficient in preventing MRSA infections in in vivo models. In conclusion, this protein CB6-C is a newly discovered antibacterial protein and has the potential to become an effective antibacterial agent due to its high therapeutic index, safety, nontoxicity and great stability.

Quercetin Liposomal Nanoformulation for Ischemia and Reperfusion Injury Treatment

Ischemia and reperfusion injury (IRI) is a common complication caused by inflammation and oxidative stress resulting from liver surgery. Current therapeutic strategies do not present the desirable efficacy, and severe side effects can occur. To overcome these drawbacks, new therapeutic alternatives are necessary. Drug delivery nanosystems have been explored due to their capacity to improve the therapeutic index of conventional drugs. Within nanocarriers, liposomes are one of the most successful, with several formulations currently in the market. As improved therapeutic outcomes have been demonstrated by using liposomes as drug carriers, this nanosystem was used to deliver quercetin, a flavonoid with anti-inflammatory and antioxidant properties, in hepatic IRI treatment. In the present work, a stable quercetin liposomal formulation was developed and characterized. Additionally, an in vitro model of ischemia and reperfusion was developed with a hypoxia chamber, where the anti-inflammatory potential of liposomal quercetin was evaluated, revealing the downregulation of pro-inflammatory markers. The anti-inflammatory effect of quercetin liposomes was also assessed in vivo in a rat model of hepatic IRI, in which a decrease in inflammation markers and enhanced recovery were observed. These results demonstrate that quercetin liposomes may provide a significant tool for addressing the current bottlenecks in hepatic IRI treatment.

Personalized Nutrition as a Key Contributor to Improving Radiation Response in Breast Cancer

Understanding metabolic and immune regulation inherent to patient populations is key to improving the radiation response for our patients. To date, radiation therapy regimens are prescribed based on tumor type and stage. Patient populations who are noted to have a poor response to radiation such as those of African American descent, those who have obesity or metabolic syndrome, or senior adult oncology patients, should be considered for concurrent therapies with radiation that will improve response. Here, we explore these populations of breast cancer patients, who frequently display radiation resistance and increased mortality rates, and identify the molecular underpinnings that are, in part, responsible for the radiation response and that result in an immune-suppressive tumor microenvironment. The resulting immune phenotype is discussed to understand how antitumor immunity could be improved. Correcting nutrient deficiencies observed in these populations should be considered as a means to improve the therapeutic index of radiation therapy.

Therapeutic Index of Herbal Medicine in Pandemic COVID-19: A Review

The study of this review focus on effective herbal medicine against COVID-19. There have been many such plants on which a lot of research has been done earlier, and these have been very good for health as we know that the current situation of the whole world is very serious with the novel COVID-19 virus epidemic. Hence, people consume a lot of herbal medicine to increase their immunity, such as kadha (brewing), and it is also very effective against this viral infection. If we take brewing in the proper dose, research should be done from clinical trials. We have been taking many medicines since old times and have been doing research on them which is Antiviral and useful in different types of infection caused by bacteria, viruses, microbes, etc. The plant's diversity included their chemical constituents, showing the promise of their therapeutic level against the antiviral activity, without any toxicity with plasma concentration. Many plants show effectively against viral infections that are Flavonoids, Glycosides, polyphenols, alkaloids, etc.. Still, any clinical trials on humans do not prove their proper research on them, but the Chinese system of medicine claimed that Traditional Chinese medicine improves the COVID-19 patient. According to this review, we aim to collate data of plants the various large in the quantity of natural active constituents from individual medicinal plant species that may have potential therapeutic efficacy. The continuing development of novel antiviral drugs needs to isolate and synthesize more new active constituents.