A Rapid and Sensitive UHPLC-MS/MS Method for Determination of Chlorogenic Acid and Its Application to Distribution and Neuroprotection in Rat Brain.

Chlorogenic acid (5-CQA) is a phenolic natural product that has been reported to improve neurobehavioral disorders and brain injury. However, its pharmacokinetics and distribution in the rat brain remain unclear. In this study, we established a rapid and sensitive UHPLC-MS/MS method for the determination of 5-CQA in rat plasma, cerebrospinal fluid (CSF), and brain tissue to investigate whether it could pass through the blood-brain barrier (BBB) and its distribution in the rat brain, and a Caenorhabditis elegans (C. elegans) strain paralysis assay was used to investigate the neuroprotective effect of 5-CQA in different brain tissues. Chromatographic separation of 5-CQA and glycyrrhetinic acid (GA, used as internal standard) was completed in 0.5 min, and the full run time was maintained at 4.0 min. Methodological validation results presented a high accuracy (95.69-106.81%) and precision (RSD ≤ 8%), with a lower limit of quantification of 1.0 ng/mL. Pharmacokinetic results revealed that 5-CQA can pass through the BBB into the CSF, but the permeability of BBB to 5-CQA (ratio of mean AUC0-∞ of CSF to plasma) was only approximately 0.29%. In addition, 5-CQA can penetrate into the rat brain extensively and is distributed with different intensities in different nuclei. A C. elegans strain paralysis assay indicated that the neuroprotective effect of 5-CQA is positively correlated with its content in different brain tissues. In conclusion, our study for the first time explored the BBB pass rate and brain tissue distribution of 5-CQA administered via the tail vein by the UHPLC-MS/MS method and investigated the potential main target area of 5-CQA for neuroprotection, which could provide a certain basis for the treatment of nervous system-related diseases of 5-CQA.

A rapid and sensitive UHPLC-MS/MS method for the determination of ziyuglycoside I and its application in a preliminary pharmacokinetic study in healthy and leukopenic rats.

Ziyuglycoside I (ZgI), one of the main active ingredients in the popular Diyushengbai tablet made from Sanguisorba officinalis L., has been proven to relieve leukopenia clinically. However, to our knowledge, no studies have investigated the pharmacokinetics of either Diyushengbai tablet or ZgI in leukopenic vs. healthy individuals. In the present study, a rapid and sensitive UHPLC-MS/MS method was developed for detecting ZgI. On using this method on a novel cyclophosphamide-induced leukopenia model, we investigated differences in the pharmacokinetic characteristics of ZgI between leukopenic and normal rats. Chromatographic separation of ZgI and glycyrrhetinic acid (IS) was achieved via gradient elution in 0.5 min, and the total run time lasted for 5 min. Methodological validation results presented a good accuracy (102.6 %-110.8 %) and precision (% RSD ≤ 13.8) with a limit of quantitation of 0.5 ng/mL. Pharmacokinetic results showed a significantly shortened peak time (Tmax) (0.93 vs. 0.33 h) while a remarkably decreased maximum concentration (Cmax) (7.96 vs. 3.40 ng/L) in the 20 mg/kg leukopenia group in comparison with those in the 20 mg/kg normal group. In addition, a prolonged elimination half-life (t1/2ß) was observed in the 20 mg/kg leukopenia group (5.02 vs. 18.51 h). We observed similar trends in the 5 mg/kg oral dosing treatment and control groups, except for Cmax, which did not differ between the groups. We did not find pharmacokinetic differences in ZgI between the two leukopenia groups. Thus, the pharmacokinetic parameters of ZgI (e.g., Tmax, Cmax, and T1/2ß) changed based on the presence of a leukopenic state. This study may provide guidance for the development of ZgI as an agent for the treatment of leukopenia.

Antitumor Effects of Trimethylellagic Acid Isolated From Sanguisorba officinalis L. on Colorectal Cancer via Angiogenesis Inhibition and Apoptosis Induction.

Previous studies have demonstrated that tannin could inhibit the proliferation and angiogenesis of cancer cells. However, the mechanism(s) associated with its antitumor effect remains unclear. Here, we investigated the effects of 3,3',4'-trimethylellagic acid (TMEA), a tannin compound isolated from Sanguisorba officinalis L., on the proliferation, angiogenesis, and apoptosis in cancer cells, as well as the underlying mechanism(s) related to its antitumor activity. TMEA was isolated from Sanguisorba officinalis L. by silica gel column chromatography. Molecular docking was carried out to assess active pocket binding between TMEA and vascular endothelial growth factor receptor 2 (VEGFR2). The antiangiogenic effect of TMEA on the migration and tube formation was detected in HUVECs by wound healing and tube formation assays, respectively. The antitumor effects of TMEA on the cell proliferation were determined in HepG2, A549, and SW620 cells by MTS assay in vitro and on the tumor growth of SW620 xenografts bearing in nude mice in vivo. The mRNA expression of Bcl-2, Bax, caspase-3, VEGF, PI3K, and mTOR were measured by qRT-PCR and protein expression of Bcl-2, Bax, caspase-3, VEGF, PI3K, and mTOR by Western blotting, and the protein expression of Bcl-2, Bax, caspase-3 and CD31 were detected by immunohistochemical analysis in vivo, respectively. The results showed that TMEA combined with VEGFR2 in the functional pockets of Asn223A, Gly922A, and Leu840A and inhibited the proliferation, migration, tube formation, and expression of VEGF and its downstream signaling mediators in HUVECs. TMEA also significantly inhibited the proliferation of HepG2, A549, and SW620 cancer cells in vitro, and suppressed the growth of SW620 tumors in vivo. Moreover, TMEA upregulated the expression of proapoptotic factors Bax and caspase-3 and downregulated the expression of antiapoptotic factors CD31 and Bcl-2 in cancer cells and/or tumor tissues. The data indicate that TMEA executes its anticancer activity by inducing apoptosis and inhibiting angiogenesis in cancer cells in vitro and tumor growth in vivo. The underlying anticancer mechanism is associated with the apoptotic and VEGF/PI3K/AKT/mTOR pathways.

Efficacy and Safety of Teneligliptin in Patients With Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Background: Teneligliptin is a 3rd-generation dipeptidyl peptidase-4 (DPP-4) inhibitor. There is a limited evidence regarding the effect of teneligliptin. Therefore, this study is to assess the efficacy and safety of teneligliptin in type 2 diabetes mellitus (T2DM) patients with inadequately glycemic controlled. Methods: A search of PubMed, Medline, Embase, and The Cochrane Library during 2000.01-2018.03 was performed for randomized controlled trials of teneligliptin compared to placebo in patients with T2DM with monotherapy or add-on treatment. Results: Ten trials with 2119 patients were analyzed. Teneligliptin produced absolute reductions in glycated hemoglobin A1c (HbA1c) levels (weighted mean difference (WMD) 0.82%, 95% confidence interval (CI) [-0.91 to -0.72], p < 0.00001) compared with placebo. However, after 36-42 weeks of follow-up (open-label), HbA1c level rise higher than duration (double-blind) in teneligliptin group. Teneligliptin led to greater decrease of fasting plasma glucose (FPG) level (vs. placebo, WMD -18.32%, 95% CI [-21.05 to -15.60], p < 0.00001). Teneligliptin also significantly decreased the 2 h post-prandial plasma glucose (2 h PPG) (WMD -46.94%, 95% CI [-51.58 to -42.30], p < 0.00001) and area under the glucose plasma concentration-time curve from 0 to 2 h (AUC0-2h) for PPG (WMD -71.50%, 95% CI [-78.09 to -64.91], p < 0.00001) compared with placebo. Patients treated with teneligliptin achieved increased homeostasis model assessment of ß cell function (HOMA-ß) with 9.31 (WMD, 95% CI [7.78-10.85], p < 0.00001). However, there was no significant difference between teneligliptin and placebo in overall adverse effects (0.96 risk ratio (RR), 95% CI [0.87, 1.06], p = 0.06). The risks of hypoglycemia were not significantly different between teneligliptin and placebo (1.16 RR, 95% CI [0.59, 2.26], p = 0.66). Conclusions: Teneligliptin improved blood glucose levels and ß-cells function with low risk of hypoglycemia in patients with T2DM. Common adverse effects of teneligliptin including hypoglycemia were identified and reviewed. Risks of cardiovascular events are less certain, and more data for long-term effects are needed.