Organic nitroxyl radicals represented by 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) are known to be compounds that catalyze alcohol oxidation reactions. These catalytic reactions can be applied to a wide range of compounds with hydroxy and amino groups. It is also possible to selectively oxidize primary alcohols by designing the skeleton around the nitroxyl radical moiety for use in organic synthesis. Reactions can also be carried out by electrochemical methods, and the electrical current measured during the reaction can be used to quantify the substrates. Therefore, the combination of reactions catalyzed by nitroxyl radicals and electrochemical techniques is expected to be applied as a new analytical method. However, since the reaction does not proceed rapidly in neutral aqueous solutions, it has mostly been applied in basic aqueous solutions or organic solvents, and there have been no reports on sensor applications under physiological conditions. Herein, we have developed a novel catalyst, nortropine N-oxyl (NNO), which is highly active even in neutral aqueous solutions, and have found that it can be used for the analysis of biological components and drugs under physiological conditions. The combination of this method with enzymatic reactions made it possible to specifically detect certain compounds. In this review, we describe a novel analytical method that combines these nitroxyl radicals with electrochemical methods.

The evaluation and prediction of pharmacokinetics in humans is important in the field of drug discovery and development. Generally, human pharmacokinetics is predicted using physiologically based pharmacokinetic models that include physiological and physicochemical (drug) parameters obtained from in vitro assays. Specific organ dysfunction, such as liver disease, also affects the functions of other organs, causing unexpected pharmacokinetic fluctuations. I investigated the effect of cholestasis on intestinal drug absorption in mice subjected to bile duct ligation (BDL). The intestinal absorption and permeability of imatinib was decreased in BDL mice compared with sham-operated mice, and this may be attributed to the up-regulation of the efflux transporter, breast cancer resistance protein. However, a single-organ experimental system cannot predict such pharmacokinetic changes. To overcome this challenge, I investigated a microphysiological system (MPS) equipped with intestinal and hepatic cells for pharmacokinetic evaluation. The glucuronidation of triazolam was significantly increased in an enterohepatic MPS compared with a single-culture system. These results suggested that the elucidation of organ interactions requires the use of an MPS loaded with human cells in combination with laboratory animal studies. In this review, I present the results of my evaluation of organ interactions using animal models and MPSs in the Award for Young Scientists from the Pharmaceutical Society of Japan, Hokuriku Branch.

Chalcones are easily accessible synthetic building blocks that are used in various heterocyclic syntheses. The rearrangement reaction using an oxidant is a characteristic conversion of chalcones, but applications to organic synthesis have been limited. Here, the development of a new method for synthesizing 3-acylindoles and azaisoflavones using a chalcone rearrangement strategy with hypervalent iodine reagents was described. Furthermore, the obtained new insight was applied to the selective synthesis of two benzofuran isomers from 2-hydroxychalcone derivatives and have demonstrated this method to the synthesis of the natural product, puerariafuran.

Microbial rhodopsins are photoreceptive membrane proteins composed of seven transmembrane α-helical apoproteins (opsin) and a covalently bound retinal chromophore. Microbial rhodopsins exhibit a cyclic photochemical reaction referred to as photocycle when illuminated. During their photocycles, these proteins perform various functions such as ions transport and photosensing. Among the various functional types of rhodopsins found to date, we have focused on the utility of proton pump-type microbial rhodopsins as optogenetic tools for optical pH control in cells or organelles. To develop effective toolkits for this purpose, a deeper understanding of the proton-pumping mechanism in these rhodopsins may be required. In this review, we first introduce a useful experimental method for measuring rapid transient pH changes with photoinduced proton uptake/release using transparent tin oxide (SnO₂) or indium-tin oxide (ITO) electrodes. In addition, we describe the unique pH-dependent behavior of the photoinduced proton transfer sequence as well as the vectoriality of proton transportation in proteorhodopsin (PR) from marine eubacteria. Through intensive ITO experiments over wide pH range, including extremely high or low pH values, in combination with photoelectric measurements using Xenopus oocytes or a thin polymer film “Lumirror,” we encountered several interesting observations on photoinduced proton transfer in PR:1) proton uptake/release sequence reversal and potential proton translocation direction reversal under alkali conditions, and 2) fast proton release from D227, a secondary counterion of the protonated retinal Schiff base at acidic pH values.

Kidney-targeted drug delivery is vital in treating kidney diseases by improving therapeutic efficacy and safety. However, targeting drugs to the kidney is challenging, as drug nano-carriers are usually trapped by the reticuloendothelial system in the liver and spleen. Recently, we reported that serine-modified polyamidoamine (Ser-PAMAM) dendrimer functions as a highly potent kidney-targeting drug carrier. Further, we demonstrated that Ser-PAMAM predominantly accumulated in the kidney, especially in proximal tubules, a pattern associated with the pathogenesis of chronic kidney diseases and renal carcinoma cells. Furthermore, captopril was successfully targeted to the kidney using Ser-PAMAM, and cysteine- or S-nitrosothiol (source of nitric oxide)-loaded Ser-PAMAM effectively suppressed the occurrence of renal injury following renal ischemia/reperfusion. In this review, we summarized recent challenges in developing a kidney-targeted drug delivery system and discussed the utility of our serine modification-based improvements to this system for the efficient treatment of kidney diseases.

The effects of drugs and other low-molecular-weight compounds are complex and may be unintended by the developer. These compounds and drugs should be avoided if these unintended effects are harmful; however, unintended effects are not always as harmful as suggested by drug repositioning. Therefore, a comprehensive understanding of complex drug actions is essential. Omics data can be regarded as the nonarbitrary transformation of biological information about a sample into comprehensive numerical information comprising multivariate data with a large number of variables. However, the changes are often based on a small number of elements in different dimensions (i.e., latent variables). The omics data of compound-treated samples comprehensively capture the complex effects of compounds, including their unrecognized aspects. Therefore, finding latent variables in these data is expected to contribute to the understanding of multiple effects. In particular, it can be interpreted as decomposing multiple effects into a smaller number of easily understandable effects. Although latent variable models of omics data have been used to understand the mechanisms of diseases, no approach has considered the multiple effects of compounds and their decomposition. Therefore, we propose to decompose and understand the multiple effects of low-molecular-weight compounds without arbitrariness and have been developing analytical methods and verifying their usefulness. In particular, we focused on classical factor analysis among latent variable models and have been examining the biological validity of the estimates obtained under linear assumptions.

Neurodevelopment is one of the most complex events in human growth and is very sensitive to disruption. Various genetic factors are the main causes of neuronal dysfunction; however, recent epidemiological studies have also revealed relationships between environmental factors and the onset of neurodevelopmental disorders. Humans are regularly exposed to a wide range of environmental factors, among which fine particles have attracted recent interest. In this regards, the development of products containing nanomaterials has expanded substantially in a wide variety of fields including medicine, food, and cosmetics. As the size of the particles in these nanomaterials decreases, their reactivity at the tissue interface and their tissue penetration increases. In addition, the reduction of particle size could alter kinetics and lead to unexpected biological effects compared with those seen with conventional materials. Thus, we need to identify potential sources of unpredictable adverse effects of nanomaterials on neurodevelopment to ensure their safe use. From this perspective, nano-safety science research has been conducted through the collection of toxicity information on nanoparticles based on their physicochemical properties and kinetics via the association analysis of physicochemical properties, kinetics, and toxicity. The results of this nano-safety science research were then used in nano-safety design research to develop safer forms of nanomaterials. In this paper, we introduce findings that demonstrate that nanomaterials translocate into the brain and describe the effects on cranial nerves.

Several good manufacturing practice (GMP) compliance issues and their associated quality problems that have been revealed since 2020 have led to large-scale recalls and supply suspensions of drug products in Japan. This paper provides an overview of the causes and countermeasures for supply disruptions of low-molecular-weight chemical pharmaceutical agents, focusing on quality-related issues. A recent increase in the use of generic drugs emphasized the importance of strengthening active pharmaceutical ingredient (API) supply chains and ensuring GMP compliance among drug manufacturers. In addition, increasing recalls in the drug products of certain marketing authorization holders due to storage stability problems strongly suggests the need to improve their development process considerably. Other measures to stabilize the supply of pharmaceuticals, including increasing stockpiles of APIs, were also discussed.

Sinomenine (SIN) is a major component contained in extracts of the Chinese medicinal herb Sinomenium acutum. SIN has various pharmacological properties, including cytoprotection, immunosuppression and anti-inflammation effects. Furthermore, recent studies have reported that SIN has anti-tumor and antidepressant effects, which has created a strong need for SIN kinetic studies. This paper reports a simple and sensitive competitive enzyme-linked immunosorbent assay (ELISA) for the pharmacokinetic evaluation of SIN. Anti-SIN serum was obtained by immunizing mice with an antigen conjugated with bovine serum albumin and carboxylic modified SIN using the N-succinimidyl ester method. Enzyme labeling of SIN with horseradish peroxidase was similarly performed using carboxylic modified SIN. Under optimized conditions, this ELISA shows a linear detection range from 40 to 5000 pg/mL, and a limit of detection of 12.1 pg/mL for 50-µL samples. This assay was specific for SIN and showed very slight cross-reactivity with dextromethorphan (0.45%), dimemorfan (0.22%) and codeine (0.01%), but no cross-reactivity with 2-methoxycyclohex-2-enone (<0.001%). Using this ELISA, SIN levels were easily determined in the blood of mice after oral administration of Kampo medicine, Boiogito. The ELISA may be a valuable tool for studies of the biological and pharmacological properties of SIN.

We investigated the cytotoxicity on a mast cell line (C57 cells) of water-soluble extracts of coarse (>3 µm, PM_>3) and fine (0.05–3 µm, PM_0.05–3) atmospheric particulates collected from April 2016 to March 2019 in Fukuoka, Japan. We examined the direct cytotoxicity with punched-out membrane filter fragments of PM_>3 and PM_0.05–3 collected from April 2019 to March 2021, without extraction of the components. Also, cell proliferation and degranulation assays were conducted under conditions which caused no cytotoxicity with water-soluble extracts of PM_>3 from FY2016 and PM_>3 direct samples from FY2019. The findings revealed the significant direct cytotoxicity of many PM_>3 and all PM_0.05–3 samples, with higher cytotoxicity for PM_0.05–3 (FY2019–2020). These results were different from the cytotoxicity effects of water-soluble extracts of PM_>3 and PM_0.05–3 samples (FY2016) in previous studies. In addition, inhibition of cell proliferation and induction of degranulation were significantly induced in a few PM_>3 samples, showing a correlation with the suspended particulate matter (SPM) concentrations. This method using punched-out membrane filters is convenient and useful for assessing the direct effects of atmospheric particles on a small scale.

In recent years, there has been an urgent need to build a pediatric in-home care system with multiple occupations. This study aims to clarify the role of pharmacists in this system by investigating what visiting nurses’ expectation from them. A self-administered questionnaire survey was conducted, targeting nurses enrolled in 10 home-visit nursing facilities. Responses were received from 51 nurses at six facilities, and the questionnaire collection rate was 42.5%. The primary role of the pharmacists that nurses regarded was the management of prescribed oral medications such as “mixing powders, single-dose packages at each time” and “sorting and summarizing each time medicine packages are taken.” Other roles included providing information based on the drug’s physicochemical properties such as “the tube gets clogged easily when the medicine is administered” and “do not crush the medicine when administering it.” The findings of this study are novel because they revealed that pharmacists need to perform pharmaceutical assessments on the influences of changes in children’s physical condition and the presence or absence of effects of drugs, and share information in real time. They also need to participate in a conference at discharge. For the first time, this study revealed the roles of pharmacists expected by nurses in pediatric in-home care. However, further knowledge or training are required, especially in terms of the relationship between the symptoms in children and the medicine administered, for pharmacists to effectively practice their roles.

Opioid-induced constipation (OIC), an adverse event that occurs due to opioid analgesics, reportedly causes poor quality of life and adherence to opioid analgesics in patients. Therefore, this issue must be addressed appropriately. Naldemedine (NAL), a peripherally-acting μ-opioid receptor antagonist, is currently recommended for treating OIC when other laxatives are ineffective, but there have been no clinical reports of NAL being used prophylactically for OIC. Therefore, we conducted a retrospective survey of hospitalized patients who received NAL as prophylaxis for OIC with strong opioid analgesics to clarify the reality of this situation and to consider points to be taken into account in its clinical implementation. In this study, 61.7% of the subjects had an Eastern Cooperative Oncology Group performance status score of 3 or higher. The rate of addition of new laxatives and increased laxatives during seven days of NAL prophylaxis was 46.8%, and the rate of diarrhea was 6.1%. This study suggests that patients initiated with strong opioid analgesics during hospitalization often presented with poor performance status, and it is important to pay attention to constipation even under NAL prophylaxis. However, the incidence of diarrhea was low, and the safety of NAL prophylaxis was considered to be good.

Asthma is often exacerbated by airway infection, and some patients with severe asthma may be unresponsive to conventional corticosteroid treatment. Src family kinases (SFKs) were recently implicated in the inflammatory responses of mice induced by allergen and bacterial toxin lipopolysaccharide (LPS). Therefore, we examined the effects of dasatinib (DAS), a Src inhibitor, on airway inflammation in mice induced by ovalbumin (OVA) and LPS. Male A/J mice were sensitized to OVA Day -14 and -7, challenged with intranasal OVA on Day 0, 2, 4, 6 and 8, and on Day 10, mice were also challenged with OVA via inhalation. Mice were treated intranasally with DAS or fluticasone propionate (FP), a glucocorticoid, twice daily for 3 d starting 1 d after OVA inhalation. Moreover, some mice were also administrated LPS 2 h after DAS or FP treatment to model of asthma exacerbation. One day after the last intervention, lung tissue and bronchoalveolar lavage fluid (BALF) were collected. DAS attenuated the accumulation of inflammatory cells and cytokines/chemokines in BALF induced by both OVA and OVA+LPS, while FP did not reduce accumulations induced by OVA+LPS. Therefore, targeting SFKs may be a superior therapeutic approach for asthma exacerbation by infection.