Inhibition of neutrophil superoxide generation by shikonin is associated with suppression of cellular Ca(2+) fluxes.

Shikonin, an anti-inflammatory compound of "Shikon", inhibits the neutrophil superoxide (O2 (•-)) generation by NADPH oxidase 2 (Nox2); however, the mechanisms of how shikonin affects Nox2 activity remained unclear. We aimed to elucidate the relationship between the inhibition of Nox2 activity and influences on intracellular Ca(2+) concentration ([Ca(2+)]i) by shikonin. For this purpose, we used a simultaneous monitoring system for detecting changes in [Ca(2+)]i (by fluorescence) and O2 (•-) generation (by chemiluminescence) and evaluated the effects of shikonin on neutrophil-like HL-60 cells stimulated with N-formyl-l-methionyl-l-leucyl-l-phenylalanine (fMLP). Since fMLP activates Nox2 by elevation in [Ca(2+)]i via fluxes such as inositol 1,4,5-trisphosphate-induced Ca(2+) release (IICR) and store-operated Ca(2+) entry (SOCE), we also evaluated the effects of shikonin on IICR and SOCE. Shikonin dose-dependently inhibited the fMLP-induced elevation in [Ca(2+)]i and O2 (•-) generation (IC50 values of 1.45 and 1.12 µM, respectively) in a synchronized manner. Analyses of specific Ca(2+) fluxes showed that shikonin inhibits IICR and IICR-linked O2 (•-) generation (IC50 values: 0.28 and 0.31 µM for [Ca(2+)]i and O2 (•-), respectively), as well as SOCE and SOCE-linked O2 (•-) generation (IC50 values: 0.39 and 0.25 µM for [Ca(2+)]i and O2 (•-), respectively). These results suggested that shikonin inhibits the O2 (•-) generation by Nox2 in fMLP-stimulated neutrophils by targeting Ca(2+) fluxes such as IICR and SOCE.

Shikonin directly inhibits nitric oxide synthases: possible targets that affect thoracic aorta relaxation response and nitric oxide release from RAW 264.7 macrophages.

Recently, an isomeric mixture of herbal anti-inflammatory naphthoquinones shikonin and alkannin, and their derivatives, have been found to impair cellular responses involving nitric oxide (NO) and NO synthesis, like the acetylcholine-induced relaxation response of rat thoracic aorta and NO release from murine RAW 264.7 macrophages. However, the mechanisms of such effects, including whether NO synthase (NOS) activity is affected, remained unclear. We herein investigate possible targets of shikonin in these NOS-related events. Shikonin by itself dose-dependently inhibited the rat thoracic aorta relaxation in response to acetylcholine (pD'(2) value: 6.29). Its optical enantiomer, alkannin, was equally inhibitory in the aorta relaxation-response assay. In RAW 264.7 cells, shikonin inhibited the lipopolysaccharide-induced NO production by 82% at 1 microM. A cell-free assay to verify direct effects on NOS activity showed that shikonin inhibits all isoforms of NOS (IC(50)s, 4 - 7 microM), suggesting NOS as an inhibition target in both the events. Further possible targets of shikonin that might be involved in the inhibitions of the acetylcholine-induced aorta relaxation response and the NO generation by RAW 264.7 cells are also discussed. It is shown for the first time that shikonin inhibits NOS activity.

Shikonin changes the lipopolysaccharide-induced expression of inflammation-related genes in macrophages.

We aimed to find candidate molecules possibly involved in the anti-inflammatory activity of shikonin (active compound of "Shikon") by analyzing its effects on gene expression of lipopolysaccharide (LPS)-treated THP-1 macrophages. Polysome-associated mRNAs (those expected to be under translation: translatome) from cells treated with LPS alone (LPS: 5 µg/mL), shikonin alone (S: 100 nM), or LPS plus shikonin (LPS&S) for 3 h were analyzed by DNA microarray followed by detection of enriched pathways/gene ontologies using the tools of the STRING database. Candidate genes in enriched pathways in the comparison of LPS&S cells vs. LPS cells were analyzed by reverse-transcription quantitative real-time PCR (RT-qPCR; 1, 2, and 3 h). DNA microarray showed shikonin significantly influences gene expression. Gene expression changes between LPS&S cells and LPS cells were compared to detect relevant proteins and/or mRNAs underlying its anti-inflammatory effects: shikonin downregulated pathways which were upregulated in LPS cells, for example, 'innate immune response'. Within changed pathways, three genes were selected for RT-qPCR analyses as key candidates influencing inflammatory responses: CYBA (component of the superoxide-generating Nox2 enzyme), GSK3B (controller of cell responses after toll-like receptor stimulation), and EIF4E (a key factor of the eukaryotic translation initiation factor 4F complex that regulates abundance of other proteins involved in immune functions). All three mRNAs were decreased at 2 h, and CYBA continued low at 3 h relative to LPS cells. Given that shikonin decreased the expression of CYBA gene of Nox2, in addition to the direct inhibition of the Nox2 activity that we have previously shown, it is suggested that one of its anti-inflammatory mechanisms could be attenuation of oxidative stress.

[Development of an Informative System for Consumers and Pharmacists Aimed at the Proper Use of Kampo OTCs].

Kampo medicines must be used according to an individual's physical characteristics and symptoms to avoid lack of efficacy, adverse reactions or interactions with other drugs. As category-2 over-the-counter drugs (OTCs), Kampo OTCs are not targets of active explanations by pharmacists, and consumers usually decide to use OTCs by themselves on the basis of drug label information. However, information on the label is occasionally brief. To promote the proper use of Kampo OTCs, we herein propose an informative tool based on the Australian Shelf-Talker (information on the proper use of OTCs with a self-check questionnaire for consumers), the Self-Check Card (SCC). We also prepared the informative material, Information to the Pharmacist (IP), directed at pharmacists regarding these Kampo OTCs. We created SCCs and IPs for 16 prescriptions in the 5 most demanded categories (cold, cough/sore throat, urination problems, women's diseases, and shoulder stiffness or joint/nerve pain). The SCC with questions in a simplified language specifies individuals who should avoid the drug, or those who should consult a pharmacist before purchase, according to the safety information on the respective drug labels. The IP provides information to pharmacists on safety issues and those concerning recognition of the consumer's symptoms and physical characteristics needed for the selection of appropriate Kampo OTCs. Such SCCs and IPs are now in use in 2 pharmacies to know pharmacists' suggestions about improvements and consumer's opinions and degree of satisfaction. We believe these risk-benefit communication tools, SCC and IP, will contribute to improve the proper use of Kampo OTCs.

Medicine reclassification processes and regulations for proper use of over-the-counter self-care medicines in Japan.

OBJECTIVES: Japan has actively reclassified substances ranging from prescription drugs to over-the-counter (OTC) drugs in recent years. The sale of most OTC drugs was deregulated several times and pharmacists' supervision was deemed no longer mandatory. Japan established a new OTC evaluation system in 2015 to hear opinions from various stakeholders regarding medicine types to be reclassified. This study aimed to examine the new framework to identify candidate substances for reclassification. Moreover, we examined how to manage the safe, self-care use of OTC drugs in Japan. METHODS: The necessary regulatory information on OTC approvals as of January 2015 was collected using an Internet search and relevant databases. To highlight the characteristics of OTC drugs in Japan, the UK was selected as a comparison country because it too was actively promoting the reclassification of medicines from prescription to nonprescription status, and because of economic similarity. RESULTS: Japan and the UK have a risk-based classification for nonprescription medicines. Japan has made OTC drugs available with mandatory pharmacists' supervision, face-to-face with pharmacists, or online instruction, which is similar to the "pharmacy medicine" practiced in the UK. Japan recently reformed the reclassification process to involve physicians and the public in the process; some interactions were back to "prescription-only medicine" in the UK. CONCLUSION: It is expected that the opinion of marketers, medical professionals, and the public will improve the discussion that will greatly contribute to the safe use of drugs. Monitoring the new system will be noteworthy to ensure that OTC drug users are managing their self-care properly and visiting a doctor only when necessary. The supply methods are similar in Japan and the UK; however, the expected growth in the Japanese OTC market by the Cabinet and the industry is still uncertain.