Total polyphenol of Anemarrhena asphodeloides ameliorates advanced glycation end products-induced endothelial dysfunction by regulation of AMP-Kinase

Exosomes derived from mangiferin‑stimulated perivascular adipose tissue ameliorate endothelial dysfunction

Perivascular adipose tissue (PVAT) is considered to serve a vital role during the development of endothelial dysfunction. The current study investigated the effect of exosomes derived from mangiferin-stimulated PVAT on endothelial function, including regeneration, migration, apoptosis and inflammation. The number of exosomes secreted by PVAT was increased by stimulation with mangiferin (0.1, 1 or 10 µM), and uptake of these exosomes by endothelial cells was observed. Exosomes produced by stimulation of PVAT with mangiferin reversed the effects of inflammation-induced endothelial dysfunction following palmitic acid (PA) treatment. Furthermore, nuclear factor (NF)-κB signaling in endothelial cells was significantly increased when treated with PA-induced PVAT-derived exosomes, whereas exosomes from the supernatant of PVAT stimulated with mangiferin reduced p65 and p50 phosphorylation levels in the cells, and inhibited p65 transportation to the nucleus. Taken together, the present study demonstrated that exosomes derived from mangiferin-stimulated PVAT supernatant inhibited inflammation-induced endothelial dysfunction via modulation of NF-κB signaling.

Development and validation of a UPLC-MS/MS method for determination of Sarsasapogenin-AA22 in rat plasma and its application to a pharmacokinetic study

A sarsasapogenin derivative, sarsasapogenin-AA22 (AA22), with cyclobutylamine at the 3-hydroxyl position of sarsasapogenin, has great neuroprotective activity in PC12 cells and NO production inhibitory activity in RAW264.7 cell lines. A method was developed to determine AA22 in rat plasma which was further applied to evaluate the pharmacokinetics of AA22 after taking a single dose of AA22. Liquid chromatography tandem mass spectrometry was used in the method, while diosgenin was used as internal standard. A simple protein precipitation based on acetonitrile was utilized. A simple sample cleanup promoted the throughput of the method considerably. The method was validated over the range of 1-1000 ng/mL with a correlation coefficient > 0.99. The lower limit of quantification was 1 ng/mL for AA22 in plasma. Intra- and inter-day accuracies for AA22 were 92-111 and 100-103%, respectively, and the inter-day precision was <15%. After a single oral dose of 25 mg/kg of AA22, the mean peak plasma concentration of AA22 was 2114 ± 362 ng/mL at 6 h. The area under the plasma concentration-time curve was 196,098 ± 69,375 h ng/mL, and the elimination half-life was 8.7 ± 2.2 h.

Integrative therapy decreases the risk of lupus nephritis in patients with systemic lupus erythematosus: A population-based retrospective cohort study

ETHNOPHARMACOLOGICAL RELEVANCE

Evidence on alleviating the risk of lupus nephritis by integrative therapy with conventional medicine (CM) and herbal medicine (HM) had not been addressed.

AIM OF THE STUDY

We investigated the integrative effect associated the risk by a retrospective Systemic Lupus Erythematosus (SLE) cohort from Taiwan National Health Insurance Research Database (NHIRD).

MATERIALS AND METHODS

SLE patients with a catastrophic illness certificate (CIC) were retrospectively enrolled from the SLE cohort of the Taiwan NHIRD between 1997 and 2011. The patients were divided into an integrative medicine (IM: integrated CM plus HM) and a non-IM (CM only) group with 1:1 propensity score matching. Cox proportional regression model and the Kaplan-Meier method were conducted to estimate the hazard ratio (HR) for lupus nephritis in the cohort.

RESULTS

Among 16,645 newly diagnosed SLE patients holding a CIC (SLE/CIC), 1933 had received HM and 1571 had received no HM treatment. After propensity score matching, there were 273 patients with lupus nephritis-120 in the IM group and 153 in the non-IM group. The adjusted HR (0.68, 95% confidence interval [CI]: 0.54-0.87, p<0.01) for lupus nephritis was lower in the IM group than in the non-IM group. The adjusted HR (0.69, 95% CI: 0.54-0.88, p<0.001) for lupus nephritis was also lower in the group of patients who had received CM plus HM than in the group that received CM only. The core pattern of HM prescriptions, which were integrated with CM for preventing lupus nephritis, was "Sheng-Di-Huang" (raw Rehmannia glutinosa Libosch.), "Mu-Dan-Pi" (Paeonia suffruticosa Andr.), "Dan-Shan" (Salvia miltiorrhiza Bge.), "Zhi-Bo-Di-Huang-Wan.", and "Chi-Shao" (Paeoniae lactiflorae Rubra).

CONCLUSION

Integrative therapy decreased the risk of lupus nephritis among SLE patients in Taiwan. Further investigation of the pharmacological mechanism and clinical efficacy are warranted.

Orthogonal separation protocol for the simultaneous preparation of four medically active compounds from Anemarrhenae Rhizoma by sequential polyamide and macroporous resin adsorbent chromatography

The green and efficient preparation of natural products from biomass is considered an important area of interest in pharmaceutical applications. In this study, we aimed to provide a practical example with a popular traditional Chinese medicine, Anemarrhenae Rhizome, and showcase the orthogonal use of column chromatography with polyamide and macroporous adsorption resins to selectively concentrate and efficiently purify four bioactive compounds: neomangiferin (NMF), mangiferin (MF), timosaponin B-II (TS B-II), and timosaponin A-III (TS A-III). First, polyamide T60-100 was employed to fractionalize the crude extracts of Anemarrhenae Rhizome. Macroporous resin HPD400 was subsequently used to purify the xanthones and steroidal saponins. Under the optimized conditions, 2.31 g of NMF, 4.10 g of MF, 12.87 g of TS B-II, and 2.78 g of TS A-III were prepared from 1 kg of crude materials, and their purities were 90.0, 92.15, 90.8, and 92.61%, respectively. The results of this study indicate that the combined column chromatography with polyamide and macroporous adsorption resins can be referenced as a green and efficient alternative for large-scale purification of bioactive ingredients from herbal raw materials.

Quantification of neomangiferin in rat plasma by liquid chromatography-tandem mass spectrometry and its application to bioavailability study

Neomangiferin, a natural C-glucosyl xanthone, has recently received a great deal of attention due to its multiple biological activities. In this study, a rapid and sensitive ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for the quantification of neomangiferin in rat plasma was developed. Using chloramphenicol as an internal standard (IS), plasma samples were subjected to a direct protein precipitation process using methanol (containing 0.05% formic acid). Quantification was performed by multiple reactions monitoring (MRM) method, with the transitions of the parent ions to the product ions of m/z 583.1→330.9 for NG and m/z 321.1→151.9 for IS. The assay was shown to be linear over the range of 0.2-400 ng/mL, with a lower limit of quantification of 0.2 ng/mL. Mean recovery of neomangiferin in plasma was in the range of 97.76%-101.94%. Relative standard deviations (RSDs) of intra-day and inter-day precision were both <10%. The accuracy of the method ranged from 94.20% to 108.72%. This method was successfully applied to pharmacokinetic study of neomangiferin after intravenous (2 mg/kg) and intragastric (10 mg/kg) administration for the first time. The oral absolute bioavailability of neomangiferin was estimated to be 0.53%±0.08% with an elimination half-life (t_1/2) value of 2.74±0.92 h, indicating its poor absorption and/or strong metabolism in vivo.

Mangiferin inhibits endoplasmic reticulum stress-associated thioredoxin-interacting protein/NLRP3 inflammasome activation with regulation of AMPK in endothelial cells

BACKGROUND

Endothelial dysfunction is tightly associated with cardiovascular complications in diabetic patients. This study aims to investigate the effects of mangiferin on the regulation of endothelial homeostasis under endoplasmic reticulum stress (ER stress) conditions.

RESULTS

High glucose (25 mmol/L) exposure induced ER stress and promoted ROS production in endothelial cells. Mangiferin effectively inhibited ER stress-associated oxidative stress by attenuating IRE1α phosphorylation and reducing ROS production. In response to ER stress, thioredoxin-interacting protein (TXNIP) expression increased, followed by NLRP3 inflammasome activation and increased IL-1β secretion. Mangiferin treatment attenuated the expressions of TXNIP and NLRP3 and reduced IL-1β and IL-6 production, demonstrating its inhibitory effects on TXNIP/NLRP3 inflammasome activation. NLRP3 inflammasome activation is responsible for mitochondrial cell death. Mangiferin restored the loss of the mitochondrial membrane potential (Δψm) and inhibited caspase-3 activity, and thereby protected cells from high glucose-induced apoptosis. Moreover, mangiferin inhibited ET-1 secretion and restored the loss of NO production when cells were exposed to high glucose. Mangiferin enhanced AMPK phosphorylation and AMPK inhibitor compound C diminished its beneficial effects, indicating the potential role of AMPK in its action.

CONCLUSION

Our work showed the beneficial effects of mangiferin on the improvement of endothelial homeostasis and elucidated the molecular pathway through which mangiferin ameliorated endothelial dysfunction by inhibition of ER stress-associated TXNIP/NLRP3 inflammasome activation in endothelial cells.

SIGNIFICANCE

These findings demonstrated the beneficial effects of mangiferin on the regulation of endothelial homeostasis and indicated its potential application in the management of diabetic cardiovascular complications.