Lei Deng

Triglycerides are carried in the bloodstream as part of very low-density lipoproteins (VLDLs) and chylomicrons, which represent the triglyceride-rich lipoproteins. Triglyceride-rich lipoproteins and their remnants contribute to atherosclerosis, possibly by carrying remnant cholesterol and/or by exerting a proinflammatory effect on macrophages. Nevertheless, little is known about how macrophages process triglyceride-rich lipoproteins. Here, using VLDL-sized triglyceride-rich emulsion particles, we aimed to study the mechanism by which VLDL triglycerides are taken up, processed, and stored in macrophages. Our results show that macrophage uptake of VLDL-sized emulsion particles is dependent on lipoprotein lipase (LPL) and requires the lipoprotein-binding C-terminal domain but not the catalytic N-terminal domain of LPL. Subsequent internalization of VLDL-sized emulsion particles by macrophages is carried out by caveolae-mediated endocytosis, followed by triglyceride hydrolysis catalyzed by lysosomal acid lipase. It is shown that STARD3 is required for the transfer of lysosomal fatty acids to the ER for subsequent storage as triglycerides, while NPC1 likely is involved in promoting the extracellular efflux of fatty acids from lysosomes. Our data provide novel insights into how macrophages process VLDL triglycerides and suggest that macrophages have the remarkable capacity to excrete part of the internalized triglycerides as fatty acids.

Macrophages accumulate triglycerides under certain pathological conditions such as atherosclerosis. Triglycerides are carried in the bloodstream as part of very low-density lipoproteins (VLDL) and chylomicrons. How macrophages take up and process VLDL-lipids is not very well known. Here, using VLDL-sized triglyceride-rich emulsion particles, we aimed to study the mechanism by which VLDL-triglycerides are taken up, processed, and stored in macrophages. Our results show that macrophage uptake of emulsion particles mimicking VLDL (VLDLm) is dependent on lipoproteins lipase (LPL) and requires the lipoprotein-binding C-terminal domain of LPL but not the catalytic N-terminal domain. Subsequent internalization of VLDLm-triglycerides by macrophages is carried out by caveolae-mediated endocytosis, followed by triglyceride hydrolysis catalyzed by lysosomal acid lipase. Transfer of lysosomal fatty acids to the ER for subsequent storage as triglycerides is mediated by Stard3, whereas NPC1 was found to promote the extracellular efflux of fatty acids from lysosomes. Our data provide novel insights into how macrophages process VLDL-derived triglycerides and suggest that macrophages have the remarkable capacity to excrete part of the internalized triglycerides as fatty acids.

Scope: Peanut stem and leaf (PSL), a traditional Chinese medicine, is widely used as a dietary supplement to improve sleep quality; however, the underlying mechanism is unclear. Here, the study aims to determine whether active compounds in PSL extract exert their effects by mediating neuronal excitability.Methods and Results: Aqueous PSL extract (500 mg kg⁻¹ BW) increases the duration of total sleep (TS), slow wave sleep (SWS) and rapid eye movement sleep (REMS) in BALB/c mice after 7 and 14 continuous days of intragastric administration. Two PSL extract components with flavonoid‐like structures: 4',7‐di‐O‐methylnaringenin (DMN, 61 µg kg⁻¹ BW) and 2’‐O‐methylisoliquiritigenin (MIL, 12 µg kg⁻¹ BW), show similar effects on sleep in BALB/c mice. Moreover, incubation with DMN (50 µM) and MIL (50 µM) acutely reduces voltage‐gated sodium and potassium currents and suppresses the firing of evoked action potential in mouse cortical neurons, indicating the inhibition on neuronal excitability. Meanwhile, RNA‐seq analysis predicts the potential regulation of voltage‐gated channels, which is according with the molecular docking simulation that both MIL and DMN can bind to voltage gated sodium channels 1.2 (Na_v1.2).Conclusions: DMN and MIL are the active ingredients of PSL that improve sleep quality, suggesting that PSL promotes sleep by regulating the excitability of neurons.

INTRODUCTION: Peanut stems and leaves (PSL) have traditionally been used as both a special food and a herbal medicine in Asia. The sedative–hypnotic and anxiolytic effects of PSL have been recorded in classical traditional Chinese literature, and more recently by many other researchers. In a previous study, four sleep‐related ingredients (linalool, 5‐hydroxy‐4′,7‐dimethoxyflavanone, 2′‐O‐methylisoliquiritigenin and ferulic acid), among which 5‐hydroxy‐4′,7‐dimethoxyflavanone and 2′‐O‐methylisoliquiritigenin were newly found in Arachis species, were screened by ultrahigh‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry (UHPLC/QTOF‐MS). In the current study, quantitative examination of the above four ingredients was conducted. Serious fundamental functional studies were done in mice, including locomotor activity, direct sleep tests, pentobarbital‐induced sleeping time tests, subthreshold dose of pentobarbital tests and barbital sodium sleep incubation period tests, to determine the material base for the sedative–hypnotic and anxiolytic effects of aqueous extracts of PSL. Furthermore, neurotransmitter levels in three brain regions (cerebrum, cerebellum and brain stem) were determined using UHPLC coupled with triple‐quadrupole mass spectrometry (UHPLC/QQQ‐MS) in order to elucidate the exact mechanism of action.RESULTS: Aqueous extract of PSL at a dose of 500 mg kg⁻¹ (based on previous experience), along with different concentrations of the above four functional ingredients (189.86 µg kg⁻¹ linalool, 114.75 mg kg⁻¹ 5‐hydroxy‐4′,7‐dimethoxyflavanone, 32.4mg kg⁻¹ 2′‐O‐methylisoliquiritigenin and 44.44 mg kg⁻¹ ferulic acid), had a sedative−hypnotic effect by affecting neurotransmitter levels in mice.CONCLUSION: The data demonstrate that these four ingredients are the key functional factors for the sedative–hypnotic and anxiolytic effects of PSL aqueous extracts and that these effects occur via changes in neurotransmitter levels and pathways. © 2018 Society of Chemical Industry

Summary: High‐pressure microfluidisation (HPM) pretreatment was applied to increase in vitro antihypertensive activity of peanut peptide fractions (PPF). The morphology of protein in aqueous dispersion revealed that peanut protein isolate (PPI) disaggregated at relatively low pressure (≤120 MPa) and re‐aggregated at relatively high pressures (150–210 MPa). The treated pressure of 120 MPa could lead to the most disaggregation of PPI. Small peptides contents, trichloroacetic acid‐nitrogen soluble index (TCA‐NSI) and degree of hydrolysis (DH) of peanut protein hydrolysates (PPH) all reached the highest at 120 MPa. Consequently, it possessed the highest angiotensin converting enzyme (ACE) and renin inhibitory activity. The highest surface hydrophobicity occurred at 120 MPa pretreatment samples. Thirty‐nine oligopeptides at 120 MPa pretreatment were identified by ultra‐performance liquid chromatography‐quadrupole time‐of‐flight (UPLC‐Q‐TOF) mass spectrometer combined with Progenesis QI for Proteomics software compared with 29 and 35 at control and 210 MPa, respectively. This meant that disaggregation of PPI at 120 MPa resulted in the release of new hydrophobic peptide.

Peanut stems and leaves have been used traditionally as both herbal medicines and special food in Asia. In this study, the main functional compounds of peanut stems and leaves extracts were identified using UPLC separation coupled to high resolution mass spectrometry (QTOF‐MS), and a traditional medicine library. Three different extraction solvents (ethyl acetate, petroleum ether and n‐butanol) were evaluated to prepare the extracts of peanut stems and leaves. A total of 283 chemical compounds were identified in peanut stems and leaves extracts, of which 207 compounds are tentatively new identifications in Genus Arachis. The integration of data acquisition and processing with the traditional medicine library provides a simple, efficient process to effectively facilitate the identification of chemical ingredients in complex natural product extracts. The integrated workflow for separation, detection and identification of functional compounds in natural products using UPLC/QTOF‐MS greatly improves productivity for development of traditional herbal medicines. Copyright © 2016 John Wiley & Sons, Ltd.