Ethanolic extract of Arctium lappa leaves alleviates cerebral ischemia reperfusion-induced inflammatory injury via HDAC9-mediated NF-κB pathway.

BACKGROUND: Ischemic stroke (IS) is a major cause of mortality and disability worldwide. Inflammatory response is crucial in the pathogenesis of tissue injury in cerebral infarction. Arctium lappa leaves are traditionally used to treat IS. PURPOSES: To investigate the neuroprotective effects and molecular mechanisms of the ethanolic extract of A. lappa leaves (ALLEE) on cerebral ischemia-reperfusion (CIR). METHODS: Middle cerebral artery obstruction reperfusion (MCAO/R) rats and an oxygen-glucose deprivation/reoxygenation (OGD/R) cell model were used to evaluate ALLEE pharmacodynamics. Various methods, including neurological function, 2,3,5-triphenyltetrazolium chloride, hematoxylin and eosin, and Nissl, enzyme-linked immunosorbent, and TdT-mediated dUTP nick-end labeling assays, were used to analyze the neuroprotective effects of ALLEE in vitro and in vivo. The major chemical components and potential target genes of ALLEE were screened using network pharmacology. Molecular docking, western blotting, and immunofluorescence analyses were performed to confirm the effectiveness of the targets in related pathways. RESULTS: ALLEE exerted potent effects on the MCAO/R model by decreasing the neurological scores, infarct volumes, and pathological features (p < 0.01). Furthermore, network pharmacology results revealed that the treatment of IS with ALLEE involved the regulation of various inflammatory pathways, such as the tumor necrosis factor (TNF) and chemokine signaling pathways. ALLEE also played key roles in targeting key molecules, including nuclear factor (NF)-κBIA, NF-κB1, interleukin (IL)-6, TNF-α and IL1ß, and regulating the histone deacetylase (HDAC)-9-mediated signaling pathway. In vivo and in vitro analyses revealed that ALLEE significantly regulated the NF-κB pathway, promoted the phosphorylation activation of NF-κB P65, IκB and IKK (p < 0.01 or p < 0.05), and decreased the expression levels of the inflammatory factors, IL-1ß, IL-6 and TNF-α (p < 0.01). Moreover, ALLEE significantly decreased the expression of HDAC9 (p < 0.01) that is associated with inflammatory responses. However, HDAC9 overexpression partially reversed the neuroprotective effects of ALLEE and its suppressive effects on inflammation and phosphorylation of NF-κB (p < 0.01). CONCLUSIONS: In conclusion, our results revealed that ALLEE ameliorates MCAO/R-induced experimental CIR by modulating inflammatory responses via the inhibition of HDAC9-mediated NF-κB pathway.

[A new norsesquiterpenoid from Arctium lappa leaves].

Chemical constituents were isolated and purified from ethyl acetate fraction of Arctium lappa leaves by silica gel, ODS, MCI, and Sephadex LH-20 column chromatography. Their structures were identified with multiple spectroscopical methods including NMR, MS, IR, UV, and X-ray diffraction combined with literature data. Twenty compounds(1-20) were identified and their structures were determined as arctanol(1), citroside A(2), melitensin 15-O-ß-D-glucoside(3), 11ß,13-dihydroonopordopicrin(4), 11ß,13-dihydrosalonitenolide(5), 8α-hydroxy-ß-eudesmol(6), syringin(7), dihydrosyringin(8), 3,4,3',4'-tetrahydroxy-δ-truxinate(9),(+)-pinoresinol(10), phillygenin(11), syringaresinol(12), kaeperferol(13), quercetin(14), luteolin(15), hyperin(16), 4,5-O-dicaffeoylquinic acid(17), 1H-indole-3-carboxaldehyde(18), benzyl-ß-D-glucopyranoside(19), and N-(2'-phenylethyl) isobutyramide(20). Among them, compound 1 is a new norsesquiterpenoid, and compounds 2-5, 7-8, and 18-20 are isolated from this plant for the first time.

A new norsesquiterpenoid from Arctium lappa leaves / 中国中药杂志

Chemical constituents were isolated and purified from ethyl acetate fraction of Arctium lappa leaves by silica gel, ODS, MCI, and Sephadex LH-20 column chromatography. Their structures were identified with multiple spectroscopical methods including NMR, MS, IR, UV, and X-ray diffraction combined with literature data. Twenty compounds(1-20) were identified and their structures were determined as arctanol(1), citroside A(2), melitensin 15-O-β-D-glucoside(3), 11β,13-dihydroonopordopicrin(4), 11β,13-dihydrosalonitenolide(5), 8α-hydroxy-β-eudesmol(6), syringin(7), dihydrosyringin(8), 3,4,3',4'-tetrahydroxy-δ-truxinate(9),(+)-pinoresinol(10), phillygenin(11), syringaresinol(12), kaeperferol(13), quercetin(14), luteolin(15), hyperin(16), 4,5-O-dicaffeoylquinic acid(17), 1H-indole-3-carboxaldehyde(18), benzyl-β-D-glucopyranoside(19), and N-(2'-phenylethyl) isobutyramide(20). Among them, compound 1 is a new norsesquiterpenoid, and compounds 2-5, 7-8, and 18-20 are isolated from this plant for the first time.

Arctium lappa leaves based on network pharmacology and experimental validation attenuate atherosclerosis by targeting the AMPK-mediated PPARG/LXRα pathway.

Arctium lappa (A. lappa) leaves are widely used in various traditional Chinese herbal formulae to ameliorate atherosclerosis (AS) and its complications such as stroke; however, there is no literature reporting the anti-atherosclerotic effect and mechanism of A. lappa leaves thus far. In the present study, we used network pharmacology and molecular docking approaches to examine the protective effect and potential mechanism of A. lappa leaves against AS in vivo and in vitro. From the network pharmacology, PPARG, HMGCR and SREBF2 were identified as the core targets of A. lappa leaves against AS. Further enrichment analyses of GO and KEGG pathways suggested that A. lappa leaves might play an anti-AS role by regulating metabolic processes and PPAR signalling pathways. The results of molecular docking experiment revealed that the major components of A. lappa leaves interacted with cholesterol efflux-regulating core proteins (PPARG, LXRα, ABCA1, and ABCG1), AMPK and SIRT1. Both in vivo and in vitro experimental results demonstrated that treatment with A. lappa leaves significantly lowered TC and LDL-C, increased HDL-C, and reduced cholesterol accumulation in the liver and aorta of the AS rat model and the foam cell model. Importantly, both in vivo and in vitro experimental results demonstrated that A. lappa leaves regulate the activity of the PPARG/LXRα signalling and AMPK/SIRT1 signalling pathways. Moreover, after treatment with the AMPK inhibitor Compound C in vitro, the improvement induced by A. lappa leaves was significantly reversed. In conclusion, A. lappa leaves attenuated AS-induced cholesterol accumulation by targeting the AMPK-mediated PPARG/LXRα pathway and promoting cholesterol efflux.

Analysis on Chemical Constituents and Dynamic Accumulation of Main Components in Arctium lappa Leaves / 中国实验方剂学杂志

ObjectiveTo determine the chemical constituents of burdock （Arctium lappa） leaves， and elucidate dynamic accumulation rule of four main components， in order to provide the basis for determining the suitable harvest time of burdock leaves. MethodSilica gel， macroporous resin， Sephadex LH-20， octadecylsilane chemically bonded silica （ODS）， microporous resin （MCI） column chromatography and reversed-phase preparative high performance liquid chromatography （HPLC） were used to isolate the main chemical constituents in burdock leaves. Their chemical structures were elucidated by spectroscopic techniques. HPLC-diode array detector （DAD） was used to analyze the dynamic accumulation of four components in burdock leaf. HPLC-DAD was performed on a Shim-pack GIST C18 column （4.6 mm×250 mm， 5 μm） with mobile phase of acetonitrile （A）-0.3% phosphoric acid aqueous solution （B） （0-9 min， 13%A； 9-10 min， 13%-24%A； 10-30 min， 24%A）， flow rate of 1.0 mL·min-1， column temperature of 40 ℃， and detection wavelength at 328 nm. ResultSeventeen compounds were isolated from burdock leaves， and identified as caffeic acid （1）， rutin （2）， kaempferol-3-O-rutinoside （3）， quercetin-3-O-β-D-glucopyranoside （4）， kaempferol-3-O-β-D-glucopyranoside （5）， chlorogenic acid （6）， isochlorogenic acid A （7）， daucosterol （8）， ursolic acid （9）， anemarrhenoside B （10）， （-）-secoisolariciresinol （11）， vladinol D （12）， melitensin （13）， esculetin （14）， 1-（-2-ethylphenyl）-1，2-ethanediol （15）， 1-（-4-ethylphenyl）-1，2-ethanediol （16）， 3-hydroxy-1-（4-hydroxy-3，5-dimethoxyphenyl）-1-propanone （17）. The contents of chlorogenic acid， rutin and kaempferol-3-O-rutinoside in burdock leaves showed an upward trend from April to August， and reached the highest in August. And the content of isochlorogenic acid A firstly increased and then decreased from April to August， and reached the highest in July. ConclusionCompounds 10， 12-17 were isolated from Arctium for the first time. Taking the contents of chlorogenic acid， rutin， kaempferol-3-O-rutinoside， and isochlorogenic acid A as indicators， considering the comprehensive development and utilization of burdock roots and leaves， it is recommended to harvest burdock leaves in mid-August.