Glycyrrhizin and its derivatives promote hepatic differentiation via sweet receptor, Wnt, and Notch signaling.

The acute liver disease is involved in aberrant release of high-mobility group box 1 (HMGB1). Glycyrrhizin (GL), a traditional Chinese medicine for liver disease, binds to HMGB1, thereby inhibits tissue injury. However the mode of action of GL for chronic liver disease remains unclear. We investigated the effects of glycyrrhizin (GL) and its derivatives on liver differentiation using human iPS cells by using a flow cytometric analysis. GL promoted hepatic differentiation at the hepatoblast formation stage. The GL derivatives, 3-O-mono-glucuronyl 18ß-glycyrrhetinic acid (Mono) and 3-O-[glucosyl (1 â†’ 2)-glucuronyl] 18ß-glycyrrhetinic acid increased AFP+ cell counts and albumin+ cell counts. Glucuronate conjugation seemed to be a requirement for hepatic differentiation. Mono exhibited the most significant hepatic differentiation effect. We evaluated the effects of (±)-2-(2,4-dichlorophenoxy) propionic acid (DP), a T1R3 antagonist, and sucralose, a T1R3 agonist, on hepatic differentiation, and found that DP suppressed Mono-induced hepatic differentiation, while sucralose promoted hepatic differentiation. Thus, GL promoted hepatic differentiation via T1R3 signaling. In addition, Mono increased ß-catenin+ cell count and decreased Hes5+ cell count suggesting the involvement of Wnt and Notch signaling in GL-induced hepatic differentiation. In conclusion, GL exerted a hepatic differentiation effect via sweet receptor (T1R3), canonical Wnt, and Notch signaling.

Enantiomeric determination of α-lipoic acid in urine by LC/MS/MS.

An analytical method for the enantiomeric determination of α-lipoic acid in human urine was developed to evaluate the pharmacokinetics of α-lipoic acid, an ingredient in health food. Urine samples were collected over time after administering α-lipoic acid dietary supplement to healthy subjects. The samples were cleaned up by solid-phase extraction using an Oasis® MAX cartridge. In the LC/MS/MS method, CHIRALPAK AD-3R was used as the chiral separation column and acetonitrile-methanol-formic acid (10 mM) (25:25:50, v/v/v) was used as the mobile phase. 13C4 1,2,5,6-d-l-α-Lipoic acid was used as the internal standard. MS/MS was performed by electrospray ionization (ESI) in the negative ion mode using two monitoring ion transitions (m/z 205.0 → 170.9 and m/z 209.0 → 174.9). A calibration curve was prepared in the concentration range of 0.5-100 ng/mL for each enantiomer (r > 0.9999). The limit of detection (LOD, S/N = 3) and the limit of quantification (LOQ, S/N > 10) were 0.1 ng/mL and 0.5 ng/mL, respectively. The intra-day and inter-day accuracy of α-lipoic acid enantiomers at the LOQ level (0.5 ng/mL), the low concentration level (5 ng/mL), the middle concentration level (50 ng/mL), and the high concentration level (100 ng/mL) ranged from 93.7 to 103.1%. The intra-day and inter-day precision were ≦ 6.94% and ≦ 7.05%, respectively. Calculating the mean values of pharmacokinetic parameters revealed that the AUC and Cmax values of d-α-lipoic acid were statistically significantly higher than those of l-α-lipoic acid (p < 0.05). It was suggested that l-α-lipoic acid is more bioavailable than d-α-lipoic acid despite individual differences in excretion rate.

Important role of calcium chloride in preventing carbon monoxide generation during desflurane degradation with alkali hydroxide-free carbon dioxide absorbents.

We investigated whether calcium chloride (CaCl2), a supplementary additive in carbon dioxide (CO2) absorbents, could affect carbon monoxide (CO) production caused by desflurane degradation, using a Japanese alkali-free CO2 absorbent Yabashi Lime®-f (YL-f), its CaCl2-free and 1% CaCl2-added derivatives, and other commercially available alkali-free absorbents with or without CaCl2. The reaction between 1 L of desflurane gas (3-10%) and 20 g of desiccated specimen was performed in an artificial closed-circuit anesthesia system for 3 min at 20 or 40 °C. The CO concentration was measured using a gas chromatograph equipped with a semiconductor sensor detector. The systems were validated by detecting dose-dependent CO production with an alkali hydroxide-containing CO2 absorbent, Sodasorb®. Compared with YL-f, the CaCl2-free derivative caused the production of significantly more CO, while the 1% CaCl2-added derivative caused the production of a comparable amount of CO. These phenomena were confirmed using commercially available absorbents AMSORB® PLUS, an alkali-free absorbent with CaCl2, and LoFloSorb™, an alkali-free absorbent without CaCl2. These results suggest that CaCl2 plays an important role in preventing CO generation caused by desflurane degradation with alkali hydroxide-free CO2 absorbents like YL-f.

Dietary fiber intake and depressive symptoms in Japanese employees: The Furukawa Nutrition and Health Study.

OBJECTIVE: Dietary fiber may play a favorable role in mood through gut microbiota, but epidemiologic evidence linking mood to dietary fiber intake is scarce in free-living populations. We investigated cross-sectionally the associations of dietary intakes of total, soluble, insoluble, and sources of fiber with depressive symptoms among Japanese workers. METHODS: Participants were 1977 employees ages 19-69 y. Dietary intake was assessed via a validated, brief self-administered diet history questionnaire. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale. Logistic regression was used to estimate odds ratios of depressive symptoms adjusted for a range of dietary and non-dietary potential confounders. RESULTS: Dietary fiber intake from vegetables and fruits was significantly inversely associated with depressive symptoms. The multivariable-adjusted odds ratios (95% confidence intervals) for the lowest through the highest tertile of vegetable and fruit fiber were 1.00 (reference), 0.80 (0.60-1.05), and 0.65 (0.45-0.95), respectively (P for trend = 0.03). Dietary intake of total, soluble, insoluble, and cereal fiber was not associated with depressive symptoms. CONCLUSIONS: Higher dietary fiber intake from vegetables and fruits may be associated with lower likelihood of having depressive symptoms.

Putative Epimutagens in Maternal Peripheral and Cord Blood Samples Identified Using Human Induced Pluripotent Stem Cells.

The regulation of transcription and genome stability by epigenetic systems are crucial for the proper development of mammalian embryos. Chemicals that disturb epigenetic systems are termed epimutagens. We previously performed chemical screening that focused on heterochromatin formation and DNA methylation status in mouse embryonic stem cells and identified five epimutagens: diethyl phosphate (DEP), mercury (Hg), cotinine, selenium (Se), and octachlorodipropyl ether (S-421). Here, we used human induced pluripotent stem cells (hiPSCs) to confirm the effects of 20 chemicals, including the five epimutagens, detected at low concentrations in maternal peripheral and cord blood samples. Of note, these individual chemicals did not exhibit epimutagenic activity in hiPSCs. However, because the fetal environment contains various chemicals, we evaluated the effects of combined exposure to chemicals (DEP, Hg, cotinine, Se, and S-421) on hiPSCs. The combined exposure caused a decrease in the number of heterochromatin signals and aberrant DNA methylation status at multiple gene loci in hiPSCs. The combined exposure also affected embryoid body formation and neural differentiation from hiPSCs. Therefore, DEP, Hg, cotinine, Se, and S-421 were defined as an "epimutagen combination" that is effective at low concentrations as detected in maternal peripheral and cord blood.

Characterization of nitrated phenolic compounds for their anti-oxidant, pro-oxidant, and nitration activities.

Coffee is one of the most widely consumed beverages worldwide. Evidence of the health benefits and the important contribution of coffee brew to the intake of anti-oxidants in the diet has increased coffee consumption. Chlorogenic acid (ChA) and caffeic acid (CaA) are the major phenolic compounds in coffee. However, phenolic compounds, which are generally effective anti-oxidants, can become pro-oxidants in the presence of Cu(2+) to induce DNA damage under certain conditions. On the other hand, sodium nitrite (NaNO(2)) is widely used as a food additive to preserve and tinge color on cured meat and fish. It is possible that phenolic compounds react with NaNO(2) under acidic conditions, such as gastric juice. In this study, we identified compounds produced by the reaction between ChA or CaA in coffee and NaNO(2) in artificial gastric juice. The identified phenolic compounds and nitrated phenolic compounds were assessed for their anti-oxidant, pro-oxidant, and nitration activities by performing an in vitro assay. The nitrated phenolic compounds seemed to show increased anti-oxidant activity and decreased pro-oxidant activity. However, one nitrated CaA compound that has a furoxan ring showed the ability to release NO(2)(-) in the neutral condition.

Development of quantitative analysis of 8-nitroguanine concomitant with 8-hydroxydeoxyguanosine formation by liquid chromatography with mass spectrometry and glyoxal derivatization.

Under inflammatory conditions, both 8-nitroguanine (NO2Gua) and 8-hydroxydeoxyguanosine (8-OHdG) are found in tissues. Measurements of the two types of damaged bases on nucleotides are expected to provide information pointing to the possible correlation between inflammation and carcinogenesis. For the establishment of an in vivo model, in this study, a sensitive and precise method for the determination of NO2Gua, which uses liquid chromatography with mass spectrometry (LC-MS) and 6-methoxy-2-naphthyl glyoxal (MTNG) derivatization, was developed in vitro. The procedure for DNA digestion in this method is identical to that widely used for 8-OHdG measurement, which enables us to detect the two damaged bases in the same DNA sample. In order to validate our method, we measured NO2Gua levels in DNA sample using LC-MS. A mass spectrometer equipped with an electrospray atmospheric pressure ionization source and operated in the negative ion mode (ESI-) was set up with selective ion monitoring at m/z 391 and 394 for NO2Gua-MTNG and [13C, 15N2]-NO2Gua-MTNG as surrogate standard, respectively. The average recoveries from DNA samples spiked with 25, 50 and 250 nM NO2Gua were 99.4, 99.8 and 99.1% with correction using the added surrogate standard, respectively. The limit of quantification was 3.0 nM for NO2Gua. To ascertain the applicability of our method to DNA samples harboring the two damaged bases, we measured NO2Gua and 8-OHdG levels in calf thymus DNA treated with ONOO-. As a result, both NO2Gua and 8-OHdG levels were clearly increased with ONOO- dose dependency, the amount of NO2Gua at the high dose ONOO- being almost the same as those of 8-OHdG. LC-MS was able to determine NO2Gua in a small amount of DNA sample, and is therefore expected to be a very powerful tool for the evaluation of DNA damage induced by reactive nitrogen species.