Hawthorn leaves flavonoids attenuate cardiac remodeling induced by simulated microgravity

CONTEXT

Hawthorn leaves are a kind of widely used medicinal plant in China. The major ingredient, hawthorn leaves flavonoids (HLF), have cardiotonic, cardioprotective, and vascular protective effects.

OBJECTIVE

The study evaluated the protective role of HLF in cardiac remodelling and the underlying mechanisms under simulated microgravity by hindlimb unloading rats.

MATERIALS AND METHODS

Adult male Sprague-Dawley rats were divided into control, HLF, HU (hindlimb unloading) and HU + HLF groups (n = 8). After HU and daily intragastric administration at the dose of 100 mg/kg/d for 8 weeks, cardiac function and structure were evaluated by biochemical indices and histopathology. We identified the main active compounds and mechanisms involved in the cardioprotective effects of HLF via bioinformatics and molecular docking analysis, and relative signalling pathway activity was verified by Western blot.

RESULTS

HLF treatment could reverse the HU-induced decline in LV-EF (HU, 55.13% ± 0.98% vs. HU + HLF, 71.16% ± 5.08%), LV-FS (HU, 29.44% ± 0.67% vs. HU + HLF, 41.62% ± 4.34%) and LV mass (HU, 667.99 ± 65.69 mg vs. HU + HLF, 840.02 ± 73.00 mg). Furthermore, HLF treatment significantly increased NPRA expression by 135.39%, PKG by 51.27%, decreased PDE5A by 20.03%, NFATc1 by 41.68% and Rcan1.4 by 54.22%.

CONCLUSIONS

HLF plays a protective effect on HU-induced cardiac remodelling by enhancing NPRA-cGMP-PKG pathway and suppressing the calcineurin-NFAT pathway, which provides a theoretical basis for use in clinical therapies.

Analytical Methods for the Determination of Quercetin and Quercetin Glycosides in Pharmaceuticals and Biological Samples

Flavonoids are plant-derived compounds that have several health benefits, including antioxidative, anti-inflammatory, anti-mutagenic, and anti-carcinogenic effects. Quercetin is a flavonoid that is widely present in various fruits, vegetables, and drinks. Accurate determination of quercetin in different samples is of great importance for its potential health benefits. This review, is an overview of sample preparation and determination methods for quercetin in diverse matrices. Previous research on sample preparation and determination methods for quercetin are summarized, highlighting the advantages and disadvantages of each method and providing insights into recent developments in quercetin sample treatment. Various analytical techniques are discussed including spectroscopic, chromatographic, electrophoretic, and electrochemical methods for the determination of quercetin and its derivatives in different samples. UV-Vis (Ultraviolet-visible) spectrophotometry is simple and inexpensive but lacks selectivity. Chromatographic techniques (HPLC, GC) offer selectivity and sensitivity, while electrophoretic and electrochemical methods provide high resolution and low detection limits, respectively. The aim of this review is to comprehensively explore the determination methods for quercetin and quercetin glycosides in diverse matrices, with emphasis on pharmaceutical and biological samples. The review also provides a theoretical basis for method development and application for the analysis of quercetin and quercetin glycosides in real samples.

Neuroprotective effects of hawthorn leaf flavonoids in Aβ 25–35 ‐induced Alzheimer's disease model

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by β-amyloid (Aβ) plaques, neurofibrillary tangles, neuronal cell loss, and oxidative stress. Further deposition of Aβ in the brain induces oxidative stress, neuroinflammation, and memory dysfunction. Hawthorn (Crataegus pinnatifida Bge.) leaf, a known traditional Chinese medicine, is commonly used for the treatment of hyperlipidemia, heart palpitations, forgetfulness, and tinnitus, and its main bioactive components are Hawthorn Leaf Flavonoids (HLF). In this study, we investigated the neuroprotective effects of the HLF on the Aβ_25-35 (bilateral hippocampus injection) rat model of AD. The results showed that the oral administration of HLF at a dose of 50, 100, and 200 mg/kg for 30 days significantly ameliorated neuronal cell damage and memory deficits, and markedly increased the enzyme activities of superoxide dismutase and catalase, and the content of glutathione whereas it decreased the malondialdehyde content in the Aβ_25-35 rat model of AD as well as suppressed the activation of astrocytes. In addition, HLF up-regulated Nrf-2, NQO-1, and HO-1 protein expressions. Also, it reduced neuroinflammation by inhibiting activation of astrocytes. In summary, these results indicated that HLF decreased the oxidative stress via activating Nrf-2/antioxidant response element signaling pathways, and may suggest as a potential candidate for AD therapeutic agent.

Effect of Moringa oleifera Leaf Extract on Excision Wound Infections in Rats: Antioxidant, Antimicrobial, and Gene Expression Analysis

The present study investigated the wound healing activity of Moringa oleifera leaf extract on an infected excision wound model in rats. Infection was induced using methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa. An investigation was also done to study the effect of Moringa extract on the vascular endothelial growth factor (VEGF) and transforming growth factor-beta 1 (TGF-β1) gene expression in vitro using human keratinocytes (HaCaT). The methanol extract of M. oleifera leaves was analyzed for the presence of phytochemicals by LCMS. The antimicrobial activity of the extract was also determined. Wound contraction, days for epithelization, antioxidant enzyme activities, epidermal height, angiogenesis, and collagen deposition were studied. M. oleifera showed an antimicrobial effect and significantly improved wound contraction, reduced epithelization period, increased antioxidant enzymes activity, and reduced capillary density. Effect of the extract was less in wounds infected with P. aeruginosa when compared to MRSA. The VEGF and TGF-β1 gene expression was increased by M. oleifera.

Superfruits in China: Bioactive phytochemicals and their potential health benefits - A Review

The term "superfruit" usually refers to certain fruits, which are rich in antioxidant components, therefore, are beneficial to human health. In China, there has been the concept of health preservation and dietary therapy through food intake in a long history. However, some other superfruits growing mainly in China have not attracted extensive attention, such as Cili, Goji berry, and sea buckthorn. Many studies suggested all of these superfruits showed strong antioxidant effects and anti-inflammatory activity in common. However, there are various other advantages and functions in different fruits. This article reviewed the research findings from the existing literature published about major antioxidant bioactive compounds and the potential health benefits of these fruits. The phytochemicals from superfruits are bioaccessible and bioavailable in humans with promising health benefits. More studies are needed to validate the health benefits of these superfruits. It would provide essential information for further research and functional food development.

A combined proteomic and metabolomic analyses of the priming phase during rat liver regeneration

By comparing differentially abundant proteins and metabolites, the protein expression, metabolic changes and metabolic regulation mechanisms during the priming phase of liver regeneration (LR) were investigated. We combined proteomic analysis via isobaric tags for relative and absolute quantification (iTRAQ) with metabolomic analysis via nontargeted liquid chromatography-mass spectrometry (LC-MS). LC-MS was used to examine 29 energy metabolites expression alterations in targeted metabolomics. A total number of 441 differentially expressed proteins and 65 metabolites were identified. PSMB10, PSMB5, RCG_63409, PSME4 and PSMB7 were key node proteins, these proteins are involved in the proteasome pathway. The most strongly enriched transcription factor motif was TP63. These results point out a critical role of the proteasome pathway (defense mechanisms) and of TP63 (metabolic regulator) as the key transcription factor during the priming phase of LR. Metabolomic and metabolite analysis showed that profiling indicates upregulation of arginine biosynthesis and glycolysis as the main ATP-delivering pathway. Integrative proteomic and metabolomic analysis showed that biomolecular changes were primarily related to the neurological disease, cell death and survival and cell morphology. What's more, neurotransmitters may play an important role in the regulation of LR.

Chemical basis of hawthorn processed with honey protecting against myocardial ischaemia

Hawthorn including many plants from the genus Crataegus (C.) is used for traditional medicines, herbal drugs, and dietary supplements all over the world. In China, C. pinnatifida Bge. var. major N, E. Br, and C. pinnatifida Bge. are two major species that are used as hawthorn. The purpose of this study is to assay the myocardial protection of hawthorn fruit processed with honey (MSZ) and screen the chemical basis of MSZ on this effect. Firstly, ultra-performance liquid chromatography-quadrupole time of flight-mass spectrometry (UPLC/Q-TOF-MS) was used to analyze the chemical constituents of the sliced dry fruit of hawthorn (SZ) and MSZ. Principal component analysis (PCA) was used to differentiate them. Orthogonal partial least squares-discriminate analysis (OPLS-DA) was applied to screen different compounds between SZ and MSZ, and 32 different compounds were selected. Then a pharmacodynamic test to investigate their protective effect against myocardial ischaemia was carried out. The results demonstrated that the protective effect of MSZ was better than that of SZ on the same dose. Finally, the chemical basis for the protective effect provided by MSZ against myocardial ischaemia was speculated based on correlation analysis. Taken together, all these results suggest that phenylpropanoids, organic acids, tannins, and flavonoids might be the chemical basis of MSZ protecting against myocardial ischaemia.

Evaluation of bioactive compounds and antioxidant capacity of edible feijoa (Acca sellowiana (O. Berg) Burret) flower extracts

Abstract

The research aimed to evaluate the polyphenolic composition and the antioxidant capacity of edible extracts of feijoa (Acca sellowiana (O. Berg) Burret) flowers. Phenolic compounds of whole feijoa flower (FM), feijoa petals (PM) and feijoa petals juice (PJ) were identified by high-performance liquid chromatography coupled with electrospray mass spectrometry and quantified by liquid chromatography coupled with ultraviolet/visible detection. Moreover, the total polyphenol (TP) content was measured spectrophotometrically and the antioxidant capacities of the extracts were evaluated by FRAP, CUPRAC, DPPH^·, and ABTS^·+ assays. The FM showed TP content (395.14 ± 7.91 mg GAE/L) higher than PM and PJ, and exhibited better antioxidant capacities. FM extracts were characterized by the high content of anthocyanins (115.3 ± 3.6 mg/L), flavonols (42.9 ± 3.3 mg/L) and the presence of ellagic acid (7.9 ± 0.2 mg/L) and other galloyltannins. In addition, cyanidin-3-O-glucoside and apigenin were detected in all the three extracts. The present study provided an overview on particular bioactive compounds that characterise different parts of edible feijoa flowers. Among the latter, FM proved to be the most suitable for exploitation in the food and health manufactory.

Graphic abstract

Flavonoid Constituents of Phlomis (Lamiaceae) Species Using Liquid Chromatography Mass Spectrometry

INTRODUCTION

Phlomis is one of the medicinal genera of Lamiaceae. This genus has unique medicinal properties. Consequently, appropriate methods need to be described for the identification of the chemical compounds.

OBJECTIVE

A liquid chromatography tandem mass spectrometry (LC-MS/MS) technique on a triple quadrupole mass spectrometer (TQMS) was used for separation and identification of leaf flavonoid compounds for seven Phlomis species including Phlomis kurdia, Ph. aucheri, Ph. olivieri, Ph. bruguieri, Ph. persica, Ph. anisodonta and Ph. elliptica.

METHODOLOGY

The flavonoid solution of air-dried leaves (10.5 g) was extracted using 85% methanol. The chromatogram was treated with three systems: methanol-water, chloroform-methanol and acetic acid. The extracts were analysed using LC-MS/MS. The MS² detection was performed under negative mode electrospray ionisation (ESI). The identification of constituents was based on authentic references used in the identification process.

RESULTS

A total of 35 chemical compounds were detected from which 32 were identified as flavonoids through comparison with published literature and reference standards. These compounds were distributed in four flavonoid classes. Flavones (12), flavonols (11), flavanones (8) and flavane (1) were the main groups appearing in almost all of the studied samples. The flavonoids such as naringenin, chrysoeriol, eriodictyol, dimethoxyflavanone, apigenin, luteolin, kaempferol and rhamnetin were in high proportions. Moreover, 22 flavonoid compounds were first reported in this study for Phlomis species.

CONCLUSION

The fragmentation patterns of the compounds during collision induced dissociation (CID) clarified information of the compounds analysed. The detailed flavonoid compositions of Phlomis species provide the appropriate context from phytochemical and phytotherapeutics points of view. Copyright © 2017 John Wiley & Sons, Ltd.

Simultaneous quantification of hyperin, reynoutrin and guaijaverin in mice plasma by LC-MS/MS: application to a pharmacokinetic study

A specific and sensitive LC-MS/MS assay was developed to simultaneously quantify three structurally similar flavonoid glycosides - hyperin, reynoutrin and guaijaverin - in mouse plasma. Biosamples were prepared by solid-phase extraction. Isocratic chromatographic separation was performed on an AichromBond-AQ C18 column (250 × 2.1 mm, 5 μm) with methanol-acetonitrile-water-formic acid (20:25:55:0.1) as the mobile phase. Detection of hyperin, reynoutrin, guaijaverin and internal standard [luteolin-7-O-β-d-apiofuranosyl-(1 → 6)-β-d-glucopyranoside] was achieved by ESI-MS/MS in the negative ion mode using m/z 463 → m/z 300, m/z 433 → m/z 300, m/z 433 → m/z 300 and m/z 579 → m/z 285 transitions, respectively. Linear concentration ranges of calibration curves were 4.0-800.0 ng/mL for hyperin and reynoutrin and 8.0-1600.0 ng/mL for guaijaverin when 100 μL of plasma was analyzed. We used this validated method to study the pharmacokinetics of hyperin, reynoutrin and guaijaverin in mice following oral and intravenous administration. All three quercetin-3-O-glycosides showed poor oral absorption in mice, and the absolute bioavailability of hyperin after oral administration of 100 mg/kg was 1.2%. Pretreatment with verapamil increased the peak concentration and area under the concentration-time curve of hyperin, which were significantly higher than the control values. The half-life of hyperin with verapamil was significantly prolonged compared with that of the control. Copyright © 2016 John Wiley & Sons, Ltd.

Development of reversed-phase high performance liquid chromatography methods for quantification of two isomeric flavones and the application of the methods to pharmacokinetic studies in rats

Isomers 5,7-dihydroxy-3,6,8-trimethoxy-2-phenyl-4H-chromen-4-one (5,7-dihydroxy-3,6,8 trimethoxy flavone) (flavone A) and 3,5-dihydroxy-6,7,8-trimethoxy-2-phenyl-4H-chromen-4-one (3,5-dihydroxy-6,7,8-trimethoxy flavone) (flavone B) have recently demonstrated differential antineoplastic activities against pancreatic cancer in vitro. These studies also indicated that these compounds target highly tumorigenic cells while sparing normal cells. The in vivo antitumor activities of these flavones have not been determined, and detection protocols for these compounds are needed to conduct pre-clinical assays following intravenous dosing. Here, we report methods developed using acetonitrile to extract two flavone isomers and corresponding internal standards, celecoxib and diclofenac, from rat plasma. Separation was achieved using a Shimadzu liquid chromatography system with a C18 column and mobile phase acetonitrile/water (60:40 and 70:30 for flavones A and B, respectively) containing 0.2% acetic acid and 0.05% triethylamine at a flow rate of 0.4mL/min and detection at 245nm. Calibration curves ranging from 250 to 2500ng/mL and 2500 to 100,000ng/mL for both flavones were linear (r(2)≥0.99) with the lower limits of quantification being 250ng/mL. Recovery of concentrations 250, 1000, 2500, 5000, and 100,000ng/mL ranged from 87 to 116% and 84 to 103% (n=3) for flavone A and B, respectively. Stability of both flavones after a freezing/thawing cycle yielded a mean peak ratio ≥0.92 when compared to freshly extracted samples. Intravenous administration of a 20mg/kg dose in rats yielded half-lives of 83.68±56.61 and 107.45±53.31min with clearance values of 12.99±13.78 and 80.79±35.06mL/min/kg for flavones A and B, respectively.