Simultaneous determination of 74 pesticide residues in Panax notoginseng by QuEChERS coupled with gas chromatography tandem mass spectrometry

This study established a method for the simultaneous determination of 74 pesticide residues in Panax notoginseng by QuEChERS pretreatment method coupled with GC-MS/MS,and carried out pesticide residue analysis on 20 batches of market samples in China.The samples were extracted with acetonitrile,cleaned up with primary secondary amine(PSA)and octadecylsilane(C18)and determined by GC-MS/MS in multiple reaction monitoring(MRM)mode.Matrix-matched calibration was recommended to combat the matrix effect.A good linearity was observed in the range of 10−500 ng/mL with correlation coefficients≥0.9950.The mean recoveries for most of the pesticides were in the range of 70%−120%with RSD<20%.The limits of detection ranged 0.28–2.00μg/kg,while the limits of quantification were 0.94–6.65μg/kg.Following the application of“top-down”approach,the expanded measurement uncertainty for all the analytes was<30%.The proposed method was successfully applied to determine pesticide residues in 20 market samples in China,where 9 pesticides were detected and quintozene exceeded the criteria domestically and abroad.

Identification of circRNA/miRNA/mRNA regulatory net-work involving(+)-catechin ameliorates diabetic nephropathy mice

(+)-Catechin(CE)is mainly found in green and black tea and has many biological effects,such as antiinflammatory,anti-cancer,anti-viral effects,protecting human organs,especially the kidney.This study aims to identify the circRNAs induced by CE in db/db mice and their roles in diabetic nephropathy progression.After the db/db mice were treated with CE,RNA-seq was performed to identify the differentially expressed circRNA and mRNAs.The ceRNA regulatory network was constructed and analyzed using bioinformatics software and public databases(Cytoscape,Clue GO,Mi RWalk,STRING,et al.).Our results revealed that 6 differentially expressed circRNAs are most associated with the cholinergic synapse,neurotrophin signaling pathway,and insulin signaling pathway.Among these,circRNA.5549 and circRNA.4712 might regulate Cd36,Cyp26 b1,C8 a,Cyp2 j13,Grem2 genes through ceRNA regulatory mechanism in the presence of CE treatment.The expanded network of proteins interacting with these 5 genes shows that the TGF-βsignaling pathway,signaling pathways regulating pluripotency of stem cell,fat digestion and absorption,and PPAR signaling pathway was highly enriched.Overall,circRNA.5549 and circRNA.4712 exhibit a promotive function in CE-treated db/db mice,especially in circRNA.5549/miR-29a-5P/Cd36 regulatory network,and this evidence suggest that their ceRNA regulatory network might be a therapeutic target for DN in humans.

Rapid discovery of two unprecedented meroterpenoids from Daphne altaica Pall.using molecular networking integrated with MolNetEnhancer and Network Annotation Propagation

Under the guidance of the approach which integrates molecular networking,MolNetEnhancer and Net-work Annotation Propagation(NAP),daphnaltaicanoids A and B(1 and 2)with unprecedented 9-oxa-tetracyclo[6.6.1.0^(2,6).0^(8,13)]pentadecane and tetracyclo[5.3.0.1^(2,5).2^(4,11)]tridecane central frameworks were iso-lated from Daphne altaica Pall.,representing two types of unparalleled meroterpenoid cores.Their struc-tures were elucidated by extensive spectroscopic analysis,nuclear magnetic resonance(NMR)calcula-tions,DP4+analysis and electronic circular dichroism(ECD)calculations.The plausible biosynthetic path-ways for 1 and 2 were postulated.Biologically,2 exerted potent neuroprotective activities which were su-perior to trolox at 12.5 and 25μmol/L.Moreover,1 and 2 exhibited more noticeable acetylcholinesterase inhibitory activities than donepezil.Molecular docking simulations were performed to explore the inter-molecular interaction of compounds 1 and 2 with acetylcholinesterase.The bioactivity evaluation results highlight the prospects of 1 and 2 as a novel category of neurological agents.

Pharmacokinetics and brain distribution differences of baicalin in rat underlying the effect of Panax notoginsenosides after intravenous administration

Baicalin(BA) is the most well-known flavonoid present in Radix Scutellariae. The aim of this study was to explore whether the pharmacokinetic behavior of BA in rat brain can be affected by Panax notoginsenosides(PNS), and to assess the possible mechanism for the observed effects. Specific HPLC and HPLC/MS/MS methods were developed and validated for the determination of BA in the rat plasma and brain using carbamazepine as an internal standard. BA was found to enter rat brain quickly after a single intravenous dose. When co-administered with PNS, clearance(CL) of BA from rat plasma decreased by 50.00%, while the area under the curve AUC0-t and AUC0-∞ increased 94.69% and 87.68%, respectively. On the other hand, some pharmacokinetic parameters of BA in rat brain had obvious differences after PNS was administered, such as an increase in Tmax from 5 min to 15 min, an increase in AUC0-t and AUC0-∞ by 42.75% and 29.39%, respectively, as well as a decrease in CL by 27.95%. Together, these results indicate that PNS can decrease the elimination rate of BA from rat plasma, promote the penetration of BA into rat brain, increase the concentration and slow down the elimination of BA from rat brain. The data provide important information that compatibility with PNS can promote the consequent effects of BA for the treatment of encephalopathy.

Isolation of chemical compositions as dietary antioxidant supplements and neuroprotectants from Chaga mushroom (Inonotus obliquus)

Excessive free radicals can cause oxidative stress (OS),which lead to neurodegenerative diseases (ND) are harmful to the human body.Therefore,it is necessary to explore dietary antioxidants and neuroprotectants from nutrient foods.Chaga mushroom (Inonotus obliquus ) has been used as an important functional food in many countries for centuries.This present study was carried out to discover active compounds from I.obliquus and investigate the in vitro antioxidant activity and neuroprotective activity.Sixteen natural products including two new isocoumarins (1 –2 ),a new 8-O -4′-neolignan (3 ),a new cyclic diarylheptanoid (4 ),and twelve known compounds (5 –16 ) were separated from I.obliquus .Their structures were elucidated by extensive spectroscopic analyses of high resolution electrospray mass spectrometry (HRESIMS),ultra violet (UV),and nuclear magnetic resonance (NMR).Among them,compounds 1 and 2 revealed remarkable antioxidant activities through the comprehensive analysis of DPPH,ABTS,and ferric reducing antioxidant power (FRAP) methods.Meanwhile,compound 1 demonstrated significant neuroprotective activity by increasing SH-SY5Y cells viability and preventing mitochondrial damage.Apart from that,electronic analyses were performed using the highest occupied molecular orbital (HOMO),and the lowest unoccupied molecular orbital (LUMO) to analyze compound 1 .These results indicated that compound 1 had a significant implication for the search of natural raw material to prevent OS and nerve damage in the field of functional foods,and the isocoumarin fragment as well as an oxygenated cis double-bond might be the active sites to play prominent parts in antioxidant and neuroprotective activities of compound 1 .

Ginsenoside Rg1 ameliorates bloodebrain barrier disruption and traumatic brain injury via attenuating macrophages derived exosomes miR-21 release

During the traumatic brain injury(TBI),improved expression of circulatory miR-21 serves as a diagnostic feature.Low levels of exosome-miR-21 in the brain can effectively improve neuroinflammation and bloodebrain barrier(BBB)permeability,reduce nerve apoptosis,restore neural function and ameliorate TBI.We evaluated the role of macrophage derived exosomes-miR-21(M-Exos-miR-21)in disrupting BBB,deteriorating TBI,and Rg1 interventions.IL-1β-induced macrophages(ⅡA)-Exos-miR-21 can activate NF-kB signaling pathway and induce the expressions of MMP-1,-3 and-9 and downregulate the levels of tight junction proteins(TJPs)deteriorating the BBB.Rg1 reduced miR-21-5 p content in ⅡA-Exos(RⅡA-Exos).The interaction of NMIIAe HSP90 controlled the release of Exos-miR-21,this interaction was restricted by Rg1.Rg1 could inhibit the Exos-miR-21 release in peripheral blood flow to brain,enhancing TIMP3 protein expression,MMPs proteolysis,and restricting TJPs degradation thus protected the BBB integrity.Conclusively,Rg1 can improve the cerebrovascular endothelial injury and hold the therapeutic potential against TBI disease.

Diverse sesquiterpenoids from Litsea lancilimba Merr.with potential neuroprotective effects against H_(2)O_(2)-induced SH-SY5Y cell injury

Five undescribed sesquiterpenoids(1–5),and nine known sesquiterpenoids(6–14)were obtained from the fruits of Litsea lancilimba Merr.by LC-MS/MS molecular networking strategies.Litsemene A(1)possessed a unique 8-member ring through unexpected cyclization of the methyl group on C-10 of guaiane.Their structures were elucidated by spectroscopic techniques including IR,UV,NMR,HR-ESI-MS,and their absolute configurations were assigned by ECD calculations.All isolated sesquiterpenoids were analyzed by bioinformatics and evaluated for their neuroprotective effects against H_(2)O_(2)-induced injury in human neuroblastoma SH-SY5Y cells.