Keiko Narumi

Simultaneous detection of green tea catechins and gallic acid in human serum after ingestion of green tea tablets using ion-pair high-performance liquid chromatography with electrochemical detection

We developed an analytical method for the simultaneous determination of tea catechins and gallic acid (GA) in human serum using ion-pair high-performance liquid chromatography (HPLC) with electrochemical detection. GA was measured to estimate the amount of gallate moiety produced by degradation of gallated catechins ((-)-epicatechin-3-gallate, ECG; (-)-epigallocatechin-3-gallate, EGCG). Ethyl gallate was adopted as an internal standard to correct for the extraction efficiency. To maximize extraction efficiency, a hydrophobic polytetrafluoroethylene (PTFE) filter was selected for pre-treatment prior to separation. HPLC separation was performed using a C18 reversed-phase column with a gradient mobile phase of phosphate buffer (pH 2.5) containing tetrahexylammonium hydrogensulfate as an ion-pair reagent. Using this method, (-)-epicatechin (EC), (-)-epigallocatechin (EGC), ECG, EGCG, ethyl gallate, and GA were detected as single peaks. The resolution values for target analytes were 4.0-13.0 and the mean values of the absolute recoveries of catechins and GA were 77.3-93.9%. The detection limits for catechins and GA in serum were 0.4-3.1ng/mL. The serum catechin levels of eight healthy volunteers after ingestion of a single dose of green tea tablets were measured using this method. The concentration of total catechins (free+conjugated forms) in serum peaked 60min after ingestion. From these results, this method is thought to enable the simultaneous quantification of GA, the hydrolysis product of gallated catechins, and target catechins, and to be sufficiently sensitive for pharmacokinetic studies of catechins following oral administration of green tea.

Green tea catechin, epigallocatechin‑3‑gallate, attenuates the cell viability of human non‑small‑cell lung cancer A549 cells via reducing Bcl‑xL expression

Clinical and epidemiological studies have indicated that the consumption of green tea has a number of beneficial effects on health. Epigallocatechin-3-gallate (EGCg), the major polyphenolic compound present in green tea, has received much attention as an active ingredient. Among the numerous promising profiles of EGCg, the present study focused on the anticancer effects. Apoptosis induced by EGCg and subsequent cell growth suppression have been demonstrated in a number of cell culture studies. However, the underlying mechanism of apoptotic cell death remains unclear. Thus, the aim of the present study was to identify the major molecule that mediates proapoptotic cell death by EGCg. The effect of EGCg on cell proliferation and the induction of mRNA that modulates apoptotic cell death was evaluated in the A549 human non-small-cell lung cancer cell line. In addition, morphological changes were assessed by microscopy in A549 cells that had been treated with 100 μM EGCg for 24 h. The MTT assay revealed that cell proliferation was significantly reduced by EGCg in a dose-dependent manner (3–100 μM). The mRNA expression level of B-cell lymphoma-extra large (Bcl-xL) was decreased in A549 cells following 24 h incubation with 100 μM EGCg. Therefore, the results indicated that the inhibition of cell proliferation by EGCg may be achieved via suppressing the expression of the cell death-inhibiting gene, Bcl-xL.

Naringenin suppresses macrophage infiltration into adipose tissue in an early phase of high-fat diet-induced obesity.

Obese adipose tissue is characterized by increased macrophage infiltration, which results in chronic inflammation in adipose tissue and leads to obesity-related diseases such as type 2 diabetes mellitus and atherosclerosis. The regulation of macrophage infiltration into adipose tissue is an important strategy for preventing and treating obesity-related diseases. In this study, we report that naringenin, a citrus flavonoid, suppressed macrophage infiltration into adipose tissue induced by short-term (14 days) feeding of a high-fat diet in mice; although naringenin did not show any differences in high-fat diet-induced changes of serum biochemical parameters in this short administration period. Naringenin suppressed monocyte chemoattractant protein-1 (MCP-1) in adipose tissue, and this effect was mediated in part through inhibition of c-Jun NH2-terminal kinase pathway. Naringenin also inhibited MCP-1 expression in adipocytes, macrophages, and a co-culture of adipocytes and macrophages. Our results suggest a mechanism by which daily consumption of naringenin may exhibit preventive effects on obesity-related diseases.

The detection of influenza virus at the community pharmacy to improve the management of local residents with influenza or influenza-like disease

BackgroundAs of 2014, community pharmacies in Japan are approved by the Ministry of Health, Labour and Welfare to measure lipid panel, HbA1c, glucose, ALT, AST and γ-GTP, but not to screen for influenza virus. We provided influenza virus screening tests at a community pharmacy to triage people with symptoms suggestive of influenza. Participants were given appropriate advice on how to prevent the spread of and safeguard against influenza. We subsequently evaluated the effects of community pharmacy-based influenza virus screening and prevention measures.MethodsLocal residents with symptoms suggestive of influenza participated in this study. Influenza virus screening tests using nasal samples were provided to the pharmacy, and we assessed samples for the presence of influenza virus. The study consisted of a preliminary interview, informed consent, and screening test on Day 1, and mail-in survey on Day 14.ResultsA total 52 local residents participated in the study. The number of participants and influenza virus positive results followed the same trend as the influenza epidemic in the study area. Influenza virus was found in 28.8% of samples. There was no significant difference between the appearance ratios of subjective symptoms among influenza-positive and influenza-negative groups. The percentages of participants who were first screened at the pharmacy, and those who were first screened at a clinic and then tested again at the pharmacy, were 71.2% (37/52) and 28.8% (15/52), respectively. In the latter group, 14 of 15 were negative by screening at the clinic, and one was diagnosed with influenza without testing. Subsequently, 46.8% (7/15) of participants tested positive for influenza by pharmacy-based screening. According to the mail-in survey, all influenza-positive (100%, 7/7) and 35.3% (6/17) of influenza-negative participants visited the clinic after being tested at the community pharmacy; test results between the community pharmacy and clinic were consistent. A total 64.7% (11/17) of symptomatic participants who tested negative recovered spontaneously at home.ConclusionsImplementation of influenza virus screening followed by provision of appropriate advice for both influenza-positive and influenza-negative participants at the community pharmacy showed a significant effect on improving the health of the local community.

Green Tea Catechins -Pharmacokinetic Properties and Health BeneficialEffects

In this review, we provide information on the pharmacokinetic properties of green tea catechins and their beneficial health effects. The major catechins in green tea are (-)-epicatechin (EC), its hydroxyl derivative (-)-epigallocatechin (EGC), and their gallic acid esters, (-)-epicatechin-3-gallate (ECg) and (-)-epigallocatechin-3-gallate (EGCg). We developed an analytical method for determination of the presence of green tea catechins in human serum using ion-pair HPLC with electrochemical detection to estimate the pharmacokinetic parameters of target catechins. The Cmaxvalues indicated that catechin absorption was relatively low. One of the gallated catechins, EGCg, had a longer half-life than the non-gallated catechins. Green tea catechins, in particular, have attracted attention as cancer preventive agents in terms of their low toxicity and being readily available to the general population. Several epidemiological studies revealed that green tea consumption reduces cancer incidence. Numerous in vitro cell culture studies have shown that EGCg, which is defined as a major green tea catechin contributing to green tea’s anticancer effects, inhibits cell growth concomitant with induction of apoptosis. We have previously found that the cell death-inhibiting gene, Bcl-xL, was decreased by EGCg. These results support the hypothesis that EGCg regulates cytoplasmic NF-κB and subsequently induction of apoptosis. Green tea consumption may also play a role in preventing other lifestyle-related diseases, such as cardiovascular diseases and stroke, due to its hypocholesterolemic and hypotensive activities. In conclusion, habitual green tea drinking may promote human health by preventing lifestyle-related diseases.