Vanillic acid alleviates palmitic acid-induced oxidative stress in human umbilical vein endothelial cells via Adenosine Monophosphate-Activated Protein Kinase signaling pathway.

Vanillic acid (VA), one of the phenolic acids metabolized by anthocyanidins, can modulate vascular reactivity by reducing the superoxide. We investigated that VA alleviated fatty acid-induced oxidative stress and clarified its potential mechanisms in human umbilical vein endothelial cells (HUVECs). Our results showed that VA reduced the production of reactive oxygen species and malondialdehyde levels. It also restored mitochondrial membrane potential and enhanced the activities of antioxidant enzymes. In addition, VA promoted the expression of p-Nrf2 and HO-1 through LKB1/AMPK signaling pathway, as well as the level of SIRT1 and PGC-1α. Moreover, compound C reduced the effect of VA on the enhancement of p-Nrf2 and HO-1. These results indicated that AMPK was an important target molecule of VA in the process of alleviating oxidative stress in HUVECs, providing a new potential evidence for vascular protection of anthocyanin in vitro. PRACTICAL APPLICATIONS: As a phenolic derivative and phase II metabolite of anthocyanins in vivo, VA can be found in various edible plants and fruits. This study revealed that VA improved oxidative stress in endothelial cells stimulated by palmitic acid by activating AMPK and its downstream proteins. VA could be a potential functional material for the protection of diabetic vascular complications.

The mechanism of interactions between flavan-3-ols against a-glucosidase and their in vivo antihyperglycemic effects.

Catechin and epicatechin are flavan-3-ols, with (+)-catechin (C) and (-)-epicatechin (EC) being the most common optical isomers found in nature. In this study, we found that C and EC showed notable inhibitory activity against a-glucosidase (AGH), and that both inhibition activities reversible and competitive. Additionally, we observed that C and EC quenched the intrinsic fluorescence of AGH through a static quenching mechanism, and that the electrostatic force was the predominant driving factor in the binding reaction. Molecular docking studies indicated that the benzene-ring-4'-hydroxyphenyl construct on flavan-3-ol plays an important role in AGH inhibition, and that the inhibition increases along with increased binding of amino acid residues at this site. Furthermore, C and EC inhibited glucose absorption in everted intestine sleeves in vitro and suppressed increases in postprandial blood glucose levels in vivo. Our results suggest that C and EC are useful to protect against hyperglycemia through inhibiting the activity of a-glucosidase.

Comparison of 4 Admission Blood Pressure Indexes for Predicting 30-Day Mortality in Patients With ST-Segment Elevation Myocardial Infarction.

BACKGROUND: We compared admission systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and mean arterial pressure (MAP) in predicting 30-day all-cause mortality in patients with ST-segment elevation myocardial infarction (STEMI) without cardiogenic shock. METHODS: A retrospective study was performed in 7,033 consecutive STEMI patients. Multivariate-adjusted hazard ratios (HRs) with a 10mm Hg increment and quartiles of each blood pressure were determined by Cox proportional hazard analyses; Wald χ (2) tests were used to compare the strength of relationships. RESULTS: Totally 593 (8.4%) patients died during follow-up. Of 4 indexes, only SBP (HR 0.94 per 10mm Hg, 95% confidence interval (CI) 0.91 to 0.98; P = 0.001) and PP (HR 0.89 per 10 mmHg, 95% CI 0.85 to 0.94; P < 0.001) were significantly associated with 30-day all-cause mortality; these in the highest vs. lowest quartiles of SBP (≥140 vs. <110mm Hg) and PP (≥60 vs. <40mm Hg) had HRs of mortality of 0.70 (95% CI 0.55 to 0.87; P = 0.003) and 0.60 (95% CI 0.47 to 0.75; P < 0.001), respectively. Compared with SBP, PP was a better predictor for mortality no matter in men (χ (2) = 5.9 for per 10mm Hg, χ (2) = 10.8 for quartiles) or women (χ (2) = 15.1 for per 10mm Hg, χ (2) = 19.5 for quartiles), and the relationship remained significant after adjustment of SBP. There was a pattern of declining risk with increasing blood pressures for mortality, and this trend was mainly observed in age groups of more than 70 years. CONCLUSIONS: Pulse pressure was an independent predictor of mortality in patients with STEMI, and low admission blood pressure should serve as a warning sign.

Ultra high performance liquid chromatography with photodiode array detector and quadrupole time-of-flight tandem mass spectrometry coupled with discriminant analysis to evaluate Angelicae pubescentis radix from different regions.

A rapid and effective method was developed for the qualitative and quantitative analysis of the major chemical constituents in Angelicae pubescentis radix by ultra high performance liquid chromatography with photodiode array detection and quadrupole time-of-flight tandem mass spectrometry. The chromatographic separation was achieved on an ACQUITY UHPLC BEH C18 column (2.1 × 100 mm, 1.7 µm). Nine phenolic acids, 30 coumarins, bisabolangelone, and adenosine were identified by quadrupole time-of-flight tandem mass spectrometry. All calibration curves exhibited good linearity (r > 0.9996) within the linear ranges. The relative standard deviation calculated for intraday and interday precision, stability, and accuracy were <5%. The mean recovery ranged from 95.8 to 106%. The overall limits of detection and quantification were 0.025-0.160 and 0.100-0.560 µg/mL, respectively. Discriminant analysis was investigated as a method for evaluating the quality of the samples with 100% correction in their classification. The results demonstrated that the developed method could successfully be used to differentiate samples from different regions and could be a helpful tool for detection and confirmation of the quality of traditional Chinese medicines.

The pharmacokinetics and oral bioavailability studies of columbianetin in rats after oral and intravenous administration.

ETHNOPHARMACOLOGICAL RELEVANCE: The roots of Angelica pubescens Maxim. f. biserrata Shan et Yuan (RAP) has been used as Traditional Chinese medicine to treat rheumatic disease in China since ancient times, but its action mechanisms was not well understood. Columbianetin is one of the main active constituents isolated from RAP, which has been shown to have various biological activities, but the absorption characteristics and oral bioavailability dose proportionality of columbianetin in vivo were not studied. MATERIALS AND METHODS: Male Sprague Dawley rats (210-230 g) received either an intravenous (i.v. 5, 10 and 20 mg kg(-1)) or oral (5, 10 and 20 mg kg(-1)) dose of columbianetin. The levels of columbianetin in plasma were measured by a simple and sensitive reversed-phase high-performance liquid chromatography (HPLC) method. The simple liquid-liquid extraction with ethyl acetate was used for sample preparation. Osthole was selected as internal standard (IS). RESULTS: The chromatographic separation was accomplished on a C18 column at a flow rate of 1 mL min(-1), where water-methanol was used as mobile phase. The calibration curve of the method was linear in the concentration range of 0.05-2000 µg mL(-1). The intra and inter-day accuracy for columbianetin in rat plasma samples were within 8% and the variation was less than 8.3%. This method was suitable for the determination and pharmacokinetic study of columbianetin in rat plasma after both intravenous and oral administration. The results indicated that maximum plasma concentrations(Cmax) for the columbianetin (17-42 µg mL(-1)) were achieved at 0.3-0.5h post-oral dosing and the apparent volume of distribution (V/F) ranged from 0.38 to 0.44 L. Absolute bioavailability of columbianetin was assessed to be 81.13 ± 45.85, 81.09 ± 33.63 and 54.30 ± 23.19%, respectively. Terminal elimination half-life (T1/2) of the columbianetin after oral dosing was 60-90 min and were 2.5-3.3 fold longer than those observed for the i.v. dosing. CONCLUSIONS: The pharmacokinetic properties of columbianetin in rat after oral administration were characterized as rapid oral absorption, quick clearance and good absolute bioavailability. The bioavailability of columbianetin ranged from 54 to 81% for 5, 10 and 20 mg kg(-1) oral doses. The bioavailability of columbianetin is independent of the doses studied. Columbianetin showed dose proportionality over the dose range 5-20 mg kg(-1). The results clearly demonstrated that columbianetin was one of the material bases of RAP. Furthermore, an HPLC method was demonstrated in this study for the research of traditional Chinese medicine.

Influence of processing on pharmacokinetic of typical constituents in radix polygoni multiflori after oral administration by LC-ESI-MS/MS.

ETHNOPHARMACOLOGICAL RELEVANCE: The processed radix polygoni multiflori (P-RPM) are produced from the raw radix polygoni multiflori (R-RPM) steamed with black bean juice, but the two traditional Chinese medicines are used to treat the different diseases in clinic. In order to clarify the influence of processing on pharmacological properties of radix polygoni multiflori, an investigation was carried out to compare the pharmacokinetics of typical constituents after oral administration of P-RPM and R-RPM extracts MATERIALS AND METHODS: A simple, rapid and sensitive high performance liquid chromatography-tandem mass spectroscopy (LC-MS/MS) was developed and validated for the simultaneous determination of gallic acid, polydatin, 2,3,5,4'-tetrahydroxystilbene-2-O-ß-d-glucoside (PM-SG), resveratrol, and emodin in rat plasma. Male Sprague-Dawley rats were orally administered the two extracts with approximately the same dosage. RESULTS: It was found that gallic acid was distributed as opened one-compartment model while polydatin, PM-SG and emodin were fitted to an open two-compartment model after oral administration of raw and processed radix polygoni multiflori extract. Cmax and AUC of gallic acid were increased (P<0.01), but Cmax and AUC of PM-SG were descreased (P<0.05). AUC of polydatin and emodin were similar with that of PM-SG. However, resveratrol was not detected in plasma collected at certain intervals following oral administration of the two extracts. CONCLUSIONS: These results indicate that influence of the processing could improve the bioavailability of gallic acid and reduce the absorption of PM-SG, polydatin and emodin in rats. The LC-MS/MS method could be used to evaluate the effect of processing on pharmacokinetic of typical constituents in radix polygoni multiflori after oral administration.