Although Kampo medicine is now fully integrated into the modern Japanese healthcare system, most Kampo formulations depend on imported crude drugs from limited foreign areas. To prepare for possible shortages of crude drugs in the future, a wider scope for the supply of medicinal plants is necessary. We conducted field research and collaborated with international laboratories for phylogenic analysis and evaluation of medicinal plant resources. Our research on ephedra plants from a wide region of Eurasia has, for example, confirmed their phylogenic structure: based on DNA sequencing analysis of nuclear ribosomal internal transcribed spacer region 1 (ITS1) as well as the chloroplast intergenic spacer between trnL and trnF (trnL-F), the 8 major Chinese species and related plants grown on the continent could be divided into 3 groups. Additionally, Ephredra sinica was found to be synonymous with Ephredra dahurica and was reduced to a subspecies of Ephredra distachya. Furthermore, Ephredra likiangensis and Ephredra gerardiana, which are grouped in separate phylogenic trees, would be good candidates for medicinal material. Aconites from Hokkaido, as an example of domestic plants reviewed, were collected for phylogenic and aconitine alkaloid content analysis. The phylogenic analysis of nr ITSs revealed that the majority of specimens were genetically similar. However, the aconitine alkaloid content of the tuberous roots demonstrated that specimens from different habitats had varying alkaloid profiles. Environmental pressure of each habitat is presumed to have caused the morphology and aconitine alkaloid profiles of these genetically similar specimens to diversify.
The primary function of the skin is to act as a permeability barrier that prevents water loss from inside the body and external invasion such as by pathogens, harmful substances, and allergens. Lipids play a critical role in skin barrier formation by forming multi-lamellar structures in the stratum corneum, the outermost cell layer of the epidermis. Ceramide, the backbone of sphingolipids, accounts for more than 50% of the stratum corneum lipids. Acylceramides are epidermis-specific ceramide species essential for skin barrier formation. Decreases in acylceramide levels and changes in ceramide composition and chain-length are associated with such cutaneous disorders as ichthyosis, atopic dermatitis, and psoriasis. Acylceramide consists of a long-chain base and an amide-linked ultra-long-chain fatty acid (ULCFA, 28-36 carbon chain), which is ω-hydroxylated and esterified with linoleic acid. Although the molecular mechanism by which acylceramide is generated has not been fully understood for decades, we recently identified two genes, CYP4F22 and PNPLA1, involved in acylceramide synthesis and elucidated the entire biosynthetic pathway of acylceramide: the synthesis of ULCFA by ELOVL1 and ELOVL4, ω-hydroxylation of the ULCFA by CYP4F22, amide-bond formation with a long-chain base by CERS3, and transacylation of linoleic acid from triacylglycerol to ω-hydroxyceramide by PNPLA1 to generate acylceramide. CYP4F22 and PNPLA1 are the causative genes of ichthyosis. We demonstrated that mutations of CYP4F22 or PNPLA1 markedly reduced acylceramide production. Our recent findings provide important insights into the molecular mechanisms of skin barrier formation and of ichthyosis pathogenesis.
Grapefruit juice (GFJ) consumption has been shown to increase the bioavailability of certain orally administered drugs. The furanocoumarin derivatives Paradisin A and bergamottin, which are present in GFJ, are potent mechanism-based inhibitors of CYP3A4. The primary aim of this work was to synthesize a series of furanocoumarin derivatives with a view to determining the relationship between the structure of the inhibitors and their inhibitory CYP3A4 activity. Furanocoumarin derivatives that were more stable and accessible than the furanocoumarin derivatives in GFJ were prepared, and their ability to inhibit CYP3A4 was examined. Synthesized furanocoumarin monomers showed strong mechanism-based inhibition of CYP3A4. The furanocoumarin dimers are also mechanism-based inhibitors of CYP3A4. These monomers and dimers are more potent inhibitors of CYP3A4 than bergamottin and Paradisin A, respectively.
Functional thin films containing insulin were prepared using layer-by-layer (LbL) deposition of insulin and negatively- or positively-charged polymers on the surface of solid substrates. LbL films composed of insulin and negatively-charged polymers such as poly(acrylic acid) (PAA), poly(vinylsulfate) (PVS), and dextran sulfate (DS) were prepared through electrostatic affinity between the materials. The insulin/PAA, insulin/PVS, and insulin/DS films were stable in acidic solutions, whereas they decomposed under physiological conditions as a result of a change in the net electric charge of insulin from positive to negative. Interestingly, the insulin-containing LbL films were stable even in the presence of a digestive-enzyme (pepcin) at pH 1.4 (stomach pH). In contrast, LbL films consisting of insulin and positively-charged polymers such as poly(allylamine hydrochloride) (PAH) decomposed in acidic solutions due to the positive charges of insulin generated in acidic media. The insulin-containing LbL films can be prepared not only on the surface of flat substrates, such as quartz slides, but also on the surface of microparticles, such as poly(lactic acid) (PLA) microbeads. Thus, insulin-containing LbL film-coated PLA microbeads can be handled as a powder. In addition, insulin-containing microcapsules were prepared by coating LbL films on the surface of insulin-doped calcium carbonate (CaCO3) microparticles, followed by dissolution of the CaCO3 core. The release of insulin from the microcapsules was accelerated at pH 7.4, whereas it was suppressed in acidic solutions. These results suggest the potential use of insulin-containing microcapsules in the development of oral formulations of insulin.
Interactions between bio-macromolecules such as proteins, DNA, and polysaccharides play pivotal roles in maintaining homeostasis in living systems. For elucidating the function of biomolecules, peptides are powerful tools, compared to native proteins, because of their lower molecular weights, compatibility with chemical modification, and predictability of interaction with the target molecules. These advantages enabled us to develop peptide-based functional molecules. However, for the purposes of controlling or regulating biomolecule functions, designing artificial proteins is also an effective approach. Not only rational protein design, but also directed molecular evolution, are now regarded as powerful methods for optimizing protein function. The interactions of proteins with bio-macromolecules are usually highly specific and show high affinity because of larger interaction surfaces as compared to small molecules or peptides. Thus, the use of proteins for designing biofunctional molecules is also important for wider applications in the biotechnology field. In this review, four topics will be discussed: 1) the development of fluorescently-labeled ligands for G protein-coupled receptors (GPCR), as well as bivalent ligands for GPCR imaging and function analysis, 2) the design and synthesis of gp41 trimer mimics as HIV-1 inhibitors or vaccines, 3) the development of a ZIP tag-probe system and its application to intracellular protein imaging, and 4) the functional analysis of sequence-specific DNA recombinase for expanding the scope of genome editing. The results of these studies indicate the importance of precision in the design of peptides or proteins for regulating bio-macromolecular interactions.
Reelin is a large secreted glycoprotein that regulates embryonic neuronal lamination and adult synaptic function. Secreted Reelin binds to lipoprotein receptors expressed on neurons. The Reelin-receptor interaction induces phosphorylation of an intracellular adaptor protein Dab1, which is required for normal embryonic brain development and adult brain functions. It has been suggested that Reelin hypofunction plays a role in the pathogenesis of several neuropsychiatric diseases, such as schizophrenia, autism, and Alzheimer's disease. Thus upregulation of Reelin activity may ameliorate the symptoms of neuropsychiatric diseases. However, the regulatory mechanism underlying the functions of Reelin is largely unknown and there are no good animal models of Reelin malfunction; thus, causal relations between Reelin and neuropsychiatric diseases remain unclear. Recently, our studies have shown that proteolytic cleavage of the Reelin protein regulates its activity. Herein, we will review recent findings about relations between Reelin and Alzheimer's disease, and the mechanism underlying the regulation of Reelin function by proteolytic cleavage. Also, we will discuss the prospect of treating neuropsychiatric diseases by upregulation of Reelin activity.
Brain edema is a severe morbid complication of brain injury, characterized by excessive fluid accumulation and an elevation of intracranial pressure. However, effective anti-brain edema drugs are lacking. One of the causes of brain edema is disruption of blood-brain barrier (BBB) function, which results in extravasation of intravascular fluid. After brain damage, astrocytes are activated, and astrocyte-derived vascular endothelial growth factor-A (VEGF-A) is known to induce BBB dysfunction. Therefore maintaining BBB integrity by regulating astrocyte function is a potentially effective strategy for treating brain edema. In this review, we focus on the endothelin ETB receptor and its role in regulation of astrocyte functions. In mice, brain damage was induced by fluid percussion injury (FPI), and the resulting BBB disruption and brain edema were observed in the mouse cerebrum. BQ788, a selective ETB receptor antagonist, attenuated the FPI-induced BBB disruption and brain edema. Levels of brain VEGF-A increased after FPI, mainly in reactive astrocytes. BQ788 suppressed the FPI-induced increase in VEGF-A expression in reactive astrocytes. Moreover, intraventricular administration of VEGF neutralizing antibody also attenuated FPI-induced BBB disruption and brain edema. Claudin-5 is an endothelial tight junction protein essential for normal BBB structure and function. Levels of claudin-5 protein were reduced by FPI. Furthermore, VEGF neutralizing antibody blocked FPI-induced decrease in claudin-5. These results suggest that the ETB receptor antagonist BQ788 protects against brain edema by inhibiting VEGF-A-mediated decrease in claudin-5.
Recent reports suggest that peptide drugs such as insulin have the potential to serve as therapeutics in neurodegenerative diseases such as Alzheimer's disease. However, the transport of these drugs to the therapeutic target, the brain, is significantly hindered by the blood-brain barrier (BBB). Intranasal administration appears to be an ideal solution for drug delivery to the brain, bypassing the BBB, however the entry of peptide drugs into neuronal and epithelial cells in the olfactory mucosa remains low. In this study, we therefore examined whether intranasal coadministration of cell-penetrating peptides (CPPs) could improve nose-to-brain drug transport. In both mice and rats, we found that direct transport of insulin into the brain was significantly facilitated when coadministered with amphipathic CPP penetratin, and eventually insulin reached the deeper regions of the brain such as the hippocampus. In the mouse line senescence-accelerated mouse prone-8 (SAMP8), spatial learning tests demonstrated that long-term intranasal coadministration of insulin with penetratin improved mild memory loss in the early stages of dementia. In contrast, the severe cognitive dysfunction in the aged SAMP8 mice was preserved despite intranasal coadministration of insulin with penetratin. The immunohistological examination of the hippocampus suggested that enhanced nose-to-brain delivery of insulin had a partial neuroprotective effect but unexpectedly increased amyloid β plaque deposition. In conclusion, intranasal coadministration of insulin with CPPs has the potential to serve as a therapeutic for mild cognitive dysfunction. To identify suitable pharmacotherapy for dementia with severe pathology, further studies of nose-to-brain delivery of molecularly appropriate biopharmaceuticals are necessary.
This review describes the syntheses and antioxidant activities of carbazole alkaloids carquinostatin A, carbazomadurin A and carbazomadurin B and their related carbazoles. The key step was an allene-mediated electrocyclic reaction involving an indole [b]-bond for the construction of a highly substituted carbazole ring. Antioxidant activities of 3-oxygenated and 3,4-dioxygenated carbazole alkaloids and their related carbazoles were comprehensively evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS)+ radical scavenging assays, and cupper reducing power. Furthemore, the antioxidant activities of simple phenolic carbazoles were evaluated by DPPH and ABTS+ radical scavenging assays. After this, bond dissociation energies (BDE) and highest occupied molecule orbital energy levels (EHOMO) of a series of phenolic carbazoles, including phenolic carbazole alkaloids, were also calculated and then examined for correlation with their antioxidant activities. The phenolic carbazole core possessing a hydroxyl group at the 1-, 3-, 6-, or 8-positions could play an important role in the antioxidant activity of carbazole alkaloids. The results suggest that these compounds could serve as useful clues for designing and developing novel antioxidants.
In January 2017, counterfeits of the hepatitis C drug 'HARVONI® Combination Tablets' (HARVONI®) were found at a pharmacy chain through unlicensed suppliers in Japan. A total of five lots of counterfeit HARVONI® (samples 1-5) bottles were found, and the ingredients of the bottles were all in tablet form. Among them, two differently shaped tablets were present in two of the bottles (categorized as samples 2A, 2B, 4A, and 4B). We analyzed the total of seven samples by high-resolution LC-MS, GC-MS and NMR. In samples 2A, 3 and 4B, sofosbuvir, the active component of another hepatitis C drug, SOVALDI® Tablets 400 mg (SOVALDI®), was detected. In sample 4A, sofosbuvir and ledipasvir, the active components of HARVONI®, were found. A direct comparison of the four samples and genuine products showed that three samples (2A, 3, 4B) are apparently SOVALDI® and that sample 2A is HARVONI®. In samples 1 and 5, several vitamins but none of the active compounds usually found in HARVONI® (i.e., sofosbuvir and ledipasvir) were detected. Our additional investigation indicates that these two samples are likely to be a commercial vitamin supplement distributed in Japan. Sample 2B, looked entirely different from HARVONI® and contained several herbal constitutents (such as ephedrine and glycyrrhizin) that are used in Japanese Kampo formulations. A further analysis indicated that sample 2B is likely to be a Kampo extract tablet of Shoseiryuto which is distributed in Japan. Considering this case, it is important to be vigilant to prevent a recurrence of distribution of counterfeit drugs.
Tazobactam/piperacillin (TAZ/PIPC) is widely used in the treatment of infectious disease. In this study, three hundred and sixty-three patients who were treated with the recommended dose of TAZ/PIPC were investigated for the proportion of time above the minimum inhibitory concentration (%TAM) and the frequency of renal and liver dysfunction. Of the whole patient population, 5.23%, exhibited increased creatinine levels, 9.37% and 8.82% exhibited increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, respectively. The patients who exhibited high serum creatinine (SCr) levels before administration, exhibited significant increases of AST (p=0.0121). The patients who exhibited low albumin levels before administration, exhibited significant decreases in renal function (p=0.0041). In the case of a breakpoint (BP) of 64 μg/mL, the arrival probabilities of %TAM of 30% and 50% were 99.4% and 76.9%, respectively. We suggested that the dose of TAZ/PIPC should be adjusted according to the interview form finding and a %TAM>50% (maximal bactericidal action).
Active learning in higher education is important for learning efficacy and motivation. Accordingly, lectures that integrate strategies toward active learning, such as minute papers, debates, and collaborative learning, have become widely adopted. Minute papers facilitate communication among both teachers and students, and can be used as a tool for reviewing lectures. In the present study, we examined the effect of using minute papers on learning efficacy and motivation. To enhance the curriculum of the interdisciplinary course Yakugaku Nyumon, which consists of an omnibus lecture series and problem-based learning, minute papers with exercises were provided to applicants. In a follow-up questionnaire, students who used minute papers (S-USE) responded that they had a better understanding of the relationships, ranging from basic to clinical subject matter, than students who did not use such papers (S-NON). Using the Attention, Relevance, Confidence, and Satisfaction (ARCS) model questionnaire to measure study motivation, S-USE scored higher for some questionnaires than S-NON. This finding indicates that minute papers promoted learning motivation among students taking the Yakugaku Nyumon course. In regular examinations, the average score of S-USE was also statistically higher than that of S-NON. These results demonstrate that minute papers possibly encouraged students to actively review the lectures, thereby increasing both learning efficacy and motivation. This study shows that through promoting active, self-learning, minute papers are suitable for improving curricular strategies in subjects that rely on passive learning methods.
OTC drugs play an important role in self-medication. OTC analgesic and antipyretic drugs are widely used in Japan. The present study aimed to survey the components of OTC drug package inserts for analgesic and antipyretic drugs and to evaluate the adverse event profiles using the Japanese Adverse Drug Event Report database (JADER). The JADER contains 430587 reports from between April 2004 and November 2016; a total of 750 reports of adverse events resulted from the use of OTC analgesic and antipyretic drugs. The safety signals were detected by the reporting odds ratio (ROR). The ROR values for “Skin & subcutaneous tissue disorders”, “Immune system disorders”, and “Hepatobiliary disorders” stratified by system organ class of the Medical Dictionary for Regulatory Activities (MedDRA) were 7.58 (6.56-8.76), 4.25 (3.51-5.14), and 2.35 (1.93-2.85), respectively. OTC analgesic and antipyretic drugs containing allylisopropylacetylurea (AIAU) exhibited a significantly high reporting ratio of “Skin & subcutaneous tissue disorders” compared with the drugs without AIAU. No difference in the reported incidence of “Hepatobiliary disorders” was found between the drugs with or without acetaminophen. Our results suggested that it was important to monitor patients who use OTC analgesic and antipyretic drug containing AIAU; in particular, careful attention should be paid to skin and subcutaneous tissue disorders.