Novel lignans from Syringa pinnatifolia and protective effect against H2O2-induced oxidative injury through regulating the expression of Nrf2/HO-1 in H9c2 cells.

Phytochemical analysis of the peeled stems of Syringa pinnatifolia Hemsl. led to the discovery of 13 undescribed lignans, namely helanols A and B (1 and 2) and alashanenols W-G1 (3-13), as well as four known analogues, of which helanols A and B were lignans with novel skeleton of α-ß' linkage. The structures were unambiguously established by extensive spectroscopic analyses, NMR calculations, ECD calculations, and single crystal X-ray crystallography. Five lignans (1, 2, 5, 11 and 13) exhibited a moderate protective effect against H2O2-induced oxidative injuries in H9c2 cells with the protective rates of 11.3-20.6 % at the concentration of 0.3-20 µM, while the positive control quercetin showed protective rates of 58.7 % at 10 µM. Further mechanism investigation suggested that 1 and 2 exerted the protective effect by regulating the expression of Nrf2/HO-1.

Noralashinols D-F, New Norlignans from Syringa pinnatifolia and its Anti-Inflammation in BV2 Cells.

Four new norlignans, noralashinols D-F (1a/b-3), and two known analogues (4 and 5) were isolated from the peeled stems of Syringa pinnatifolia Hemsl. The structures were elucidated by analysis of spectroscopic data, such as IR, HR-ESI-MS, 1D and 2D NMR, and ECD. All compounds were evaluated for anti-inflammatory activities against NO production induced by LPS in BV2 microglia cells. Compounds 1b and 2 exhibited moderate activities with IC50 values of 32.39±9.1 and 47.83±10.44 µM, respectively, compared with positive control indomethacin (IC50=21.62 µM). It is worth to note that 1, 3, and 4 have a distinctive woody fragrance.

Minor Humulane and Eremophilane Sesquiterpenoids from Syringa pinnatifolia and Their Protective Effect Against Oxidative Injuries in H9c2 Cells.

As a part of systematic research, an ongoing phytochemical investigation of the sesquiterpenoid-containing fraction led to the isolation of five new sesquiterpenoids from the peeled stems of Syringa pinnatifolia, including two pairs of enantiomeric humulane-type (±)-alashanoids A1 and B1 (1 and 2) and one eremophilane-type alashanoid C1 (3). These structures were elucidated by the analysis of extensive spectroscopic data, including ESI-MS and 1D and 2D NMR, and the absolute configuration was determined by comparing its experimental and calculated electronic circular dichroism and calculated NMR. These isolates exhibited moderate in vitro cardioprotective effects against oxidative injuries in H9c2 cells.

Alashanines A-C, Three Quinone-Terpenoid Alkaloids from Syringa pinnatifolia with Cytotoxic Potential by Activation of ERK.

Three quinone-terpenoid alkaloids, alashanines A-C (1-3), possessing an unprecedented 6/6/6 tricyclic conjugated backbone and quinone-quinoline-fused characteristic, were isolated from the peeled stems of Syringa pinnatifolia. Their structures were elucidated by analysis of extensive spectroscopic data and quantum chemical calculations. A hypothesis of biosynthesis pathways for 1-3 was proposed on the basis of the potential precursor iridoid and benzoquinone. Compound 1 exhibited antibacterial activities against Bacillus subtilis and cytotoxicity against HepG2 and MCF-7 human cancer cell lines. The results of the cytotoxic mechanism revealed that compound 1 induced apoptosis of HepG2 cells through activation of ERK.

The Ethanol Extract of Syringa oblata Heartwood, a Mongolian Folk Medicine Containing Major Lignans, Exerts Analgesic and Sedative Effects on Mice.

The heartwood of Syringa oblata Lindl. (SO) is one of Mongolian folk medicines to treat insomnia and pain, while its pharmacological evaluation and underlying mechanism remain unclear. In this study, the sedative effect of ethanol extract of SO (ESO) was evaluated with the locomotor activity test and the threshold dose of pentobarbital sodium-induced sleep test in mice, and the hot plate test, acetic acid-induced writhing test, and formalin test in mice were used to evaluate its analgesic effect. The underlying mechanism of ESO analgesia was explored by RT-PCR and western blot analysis, which is associated with the regulation of the NF-κB signaling pathway. Besides, the main constituents of ESO were characterized by LC/MS data analysis and comparison with isolated pure compounds. The current findings brought evidence for clinical application and further pharmacological and phytochemical studies on SO.

[Two new isoquinoline alkaloids from Corydalis hendersonii].

Corydalis hendersonii(CH) is a Tibetan folk medicine with the functions of clearing heat, detoxifying, cooling blood, checking diarrhea, and lowering blood pressure. It is often used to treat high altitude polycythemia, vasculitis, peptic ulcer, and diarrhea. Nine compounds were separated from the ethanol extract of CH by silica gel, ODS, Sephadex LH-20 chromatography and semi-preparative HPLC. Their structures were identified as hendersine H(1),hendersine I(2), dehydrocheilanthifoline(3), protopine(4), izmirine(5), 6,7-methylenedioxy-1(2H)-isoquinolinone(6), icariside D_2(7), ethyl 4-(ß-D-glucopyranosyloxy)-3-methoxybenzoate(8), 3-hydroxy-4-methoxybenzoic acid(9), respectively, by the spectroscopic data analysis and comparison with those in the literature. Among them, compounds 1 and 2 are new isoquinoline alkaloids, and compounds 7-9 are reported the first time for Corydalis. The hypoglycemic model of H9c2 cardiomyocytes and the inflammatory model of H9c2 cardiomyocytes induced by conditional supernatant were employed to determine the activities of the above compounds. The results showed that 20 µmol·L~(-1) compound 1 had a protective effect on H9c2 cardiomyocytes and 10 µmol·L~(-1) compounds 4 and 5 inhibited H9c2 cardiomyocyte inflammation induced by conditional supernatant.

[Eleven new sesquiterpenoids from peeled stems of Syringa pinnatifolia].

The peeled stems of Syringa pinnatifolia(SP) is a representative Mongolian folk medicine with the effects of anti-depression, heat clearance, pain relief, and respiration improvement. It has been clinically used for the treatment of coronary heart disease, insomnia, asthma, and other cardiopulmonary diseases. As part of the systematic study on pharmacological substances of SP, 11 new sesquiterpenoids were isolated from the terpene-containing fractions of the ethanol extract of SP by liquid chromatography-mass spectrometry(LC-MS) and proton nuclear magnetic resonance(~1H-NMR) guided isolation methods. The planar structures of the sesquiterpenoids were identified by MS, 1D NMR, and 2D NMR data analysis, and were named pinnatanoids C and D(1 and 2), and alashanoids T-ZI(3-11), respectively. The structure types of the sesquiterpenoids included pinnatane, humulane, seco-humulane, guaiane, carryophyllane, seco-erimolphane, isodaucane, and other types. However, limited to the low content of compounds, the existence of multiple chiral centers, the flexibility of the structure, or lack of ultraviolet absorption, the stereoscopic configuration remained unresolved. The discovery of various sesquiterpenoids enriches the understanding of the chemical composition of the genus and species and provides references for further analysis of pharmacological substances of SP.

Syringenes A-L: Bioactive dimeric eremophilane sesquiterpenoids from Syringa pinnatifolia.

A phytochemical investigation guided by 1H NMR and LC-MS data on the ethanol extract of Syringa pinnatifolia stems led to the isolation of 11 new dimeric eremophilane sesquiterpenoids, namely, syringenes A-K (1-11) and one known analog (12, syringene L). These structures were elucidated by extensive analysis of spectroscopic data, single-crystal X-ray diffraction, and computational methods. Biological assays revealed that 1-12 exhibited different degrees of anti-inflammatory effects, and 5 and 6 showed significant cytotoxicity against human hepatoma HepG2 cells with IC50 values of 12.3 and 12.9 µM, respectively. Furthermore, flow cytometry assays and western blot analysis revealed that 5 and 6 promoted the apoptosis of HepG2 cells by activating ERK. Finally, the molecular docking analysis implied that the carbonyl and hydroxy groups at the C-11/C-6' of 5 and 6 had a good binding affinity with ERK.

Syringenes M - Q, Eremophilane Sesquiterpenoid Dimers from the Peeled Stems of Syringa pinnatifolia.

As a part of systematic studies on Syringa pinnatifolia, a continued phytochemical investigation guided by 1 H-NMR and LC/MS data on the ethanol extract afforded five new dimeric eremophilane sesquiterpenoids, namely syringenes M-Q (1-5). These structures were elucidated by extensive analysis of spectroscopic data, including infrared (IR), high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), nuclear magnetic resonance (NMR), quantum-mechanics-based computational analysis of NMR chemical shifts, and single-crystal X-ray diffraction. Compounds 4 and 5 showed inhibitory activities against NO production induced by lipopolysaccharide in RAW264.7 macrophage cells, with IC50 values of 5.1 and 9.3 µM, compared to positive control indomethacin (IC50 33.6 µM). These dimeric eremophilane sesquiterpenoids may be potential markers for discriminating this species from the genus Syringa and the Oleaceae family.

Alashanoids O-S, seco-Humulane and Eremophilane Sesquiterpenoids from Syringa pinnatifolia.

Five new sesquiterpenoids, alashanoids O-S (1-5), along with three known analogs (6-8) were isolated from the peeled stems of Syringa pinnatifolia. Their structures were elucidated by analysis of extensive spectroscopic data including ESI-MS, 1D, 2D NMR. The absolute configurations were determined by comparing its experimental and calculated electronic circular dichroism, calculated OR, calculated NMR, and single crystal X-ray diffraction data analysis. Compounds 1 and 2 belong to the seco-humulane type and possess a rare 13-membered oxygen heterocycle framework, and 3-5 belong to eremophilane-type. Compounds 1, 2, and 5 showed inhibitory effects against NO production in LPS-induced RAW264.7 macrophage cells with its IC50 values of 11.86±2.34, 72.08±7.72, and 69.22±15.29 µM, respectively, compared with the positive control indomethacin (IC50 =31.52 µM).

Three Pairs of Enantiomeric Sesquiterpenoids from Syringa pinnatifolia.

Three pairs of enantiomeric sesquiterpenoids, (∓)-syringanoid A (1a and 1b) and (±)-pinnatanoids A (2a and 2b) and B (3a and 3b), that represent an unprecedented 5/4/6 tricyclic backbone and a rare 6/7 bicyclic backbone, respectively, were isolated from the peeled stems of Syringa pinnatifolia. The structures were elucidated by extensive spectroscopic analysis, single-crystal X-ray diffraction, a modified Mosher's method, and quantum chemical calculations. A plausible biotransformation pathway for 1-3 was proposed, and their cardiomyocyte-protective and anti-inflammatory activities were evaluated.

(+/-)-Alashanoid N, Two Enantiomeric Sesquiterpenes from Syringa pinnatifolia.

Two enantiomeric humulane sesquiterpenes, namely (+)-alashanoid N (1a) and (-)-alashanoid N (1b), along with two known analogs ((2R,3R,5R)-2,3-epoxy-6,9-humuladien-5-ol-8-one (2) and (2R,3S,5R)-2,3-epoxy-6,9-humuladien-5-ol-8-one (3)), were described from the peeled stems of a folk Mongolian herbal medicine Syringa pinnatifolia. Their structures were characterized based on UV, IR, NMR, and HR-ESI-MS data analyses, and the absolute configurations were determined by data analysis of X-ray diffraction and quantum chemical calculations. (+/-)-Alashanoid N showed inhibition against NO production in RAW 264.7 macrophage cells with IC50 values of 90.1 µM and 71.7 µM, and protective effect against oxygen-glucose deprivation injury to H9c2 cells at a concentration of 20 µM and 5 µM, respectively.

[Research progress on in vitro models of cardiomyocyte injury].

Cardiovascular diseases seriously endanger human health and life. The accompanying myocardial injury has been a focus of attention in society. Chinese medicine,serving as a natural and precious reservoir for the research and development of new drugs,is advantageous in resisting myocardial injury due to its multi-component,multi-pathway,and multi-target characteristics. In recent years,with the extensive application of culture method for isolated cardiomyocytes,a cost-effective,controllable in vitro model of cardiomyocyte injury with uniform samples is becoming a key tool for mechanism research on cardiomyocyte injury and drug development.A good in vitro model can reduce experimental and manpower cost,and also accurately stimulate clinical changes to reveal the mechanism. Therefore,the selection and establishment of in vitro model are crucial for the in-depth research. This study summarized the modeling principles,evaluation indicators,and application of more than ten models reflecting different clinical conditions,such as injuries induced by hypoxia-reoxygenation,hypertrophy,oxidative stress,inflammation,internal environmental disturbance,and toxicity. Furthermore,we analyzed advantages and technical difficulties,aiming to provide a reference for in-depth research on myocardial injury mechanism and drug development.

[Effect of total phenolic part of Rhus chinensis against myocardial ischemia in mice].

Rhus chinensis is an important resource plant. The aqueous extract of R. chinensis roots or stems was to produce Shuguantong Syrup, which is mainly used for the treatment of coronary heart disease and angina pectoris with definite curative effect. On this basis, the crude phenolic part of R. chinensis prepared by macroporous resin was evaluated for the cardio protective effect against myocardial ischemia in mice. The results showed that the phenolic part group with oral administration at the dosages of 190.8-381.6 mg·kg~(-1), compared with the model group, reduced the values of left ventricular end systolic diameter(LVEDs) and the left ventricular end diastolic diameter(LVEDd), and increased the cardiac ejection fraction(EF) and left ventricular fractional shortening(FS) rate, which could effectively improve cardiac function and exert its anti-myocardial ischemia effect, and reduce the rising levels of creatine kinase isoenzyme(CK-MB) and lactate dehydrogenase(LDH) in serum. HE staining showed that the phenolic part group reduced the infiltration of myocardial inflammatory cells and alleviated the degree of myocardial fibrosis and collagen deposition. TUNEL staining showed that the blue-green fluorescence of the phenolic part group decreased successively, and the degree of myocardial cell apoptosis was reduced. Immunohistochemical staining suggested that it could reduce the number of positive cells for p53 protein expression and significantly improve myocardial cell damage. All above data suggested that the phenolic part group had an anti-mycardial ischemis effect. Related mechanism studies revealed that the crude phenolic part could regulate the expressions of the p53 gene(p53), Bcl-2-associated X protein(Bax), B lymphoma-2 gene(Bcl-2), and caspase-3 protein(caspase-3) in myocardial tissue, suggesting that it could reduce cardiac remodeling and myocardial ischemic damage, and improve cardiac function by inhibiting myocardial apoptosis.This research laid a foundation for the elucidation of the pharmacological ingredients R. chinensis.

[Network pharmacology study of Tibetan medicine Corydalis Herba against acute myocardial ischemia].

In this study, the compound search was completed through SciFinder and CNKI databases, and the drug-like properties were screened in FAFdrugs4 and SEA Search Server databases. In addition, based on the target sets related to acute myocardial ischemia(AMI) searched in disease target databases such as OMIM database, GeneCards database and DrugBank, a network diagram of chemical component-target-pathway-disease was established via Cytoscape to predict the potential active components of Corydalis Herba, a traditional Tibetan herbal medicine which derived from the aerial parts of Corydalis hendersonii and C. mucronifera against AMI. A protein-protein interaction(PPI) network was constructed through the STRING database and the core targets in the network were predicted. And the enrichment analyses of core targets were completed by DAVID database and R software. Furthermore, a molecular docking method was used to verify the binding of the components with core targets using softwares such as Autodock Vina. The present results showed that there were 60 compounds related to AMI in Corydalis Herba, involving 73 potential targets. The GO functional enrichment analysis obtained 282 biological processes(BP), 49 cell components(CC) and 78 molecular functions(MF). KEGG was enriched into 85 pathways, including alcoholism pathway, endocrine resistance pathway, calcium signaling pathway, cAMP signaling pathway, vascular endothelial growth factor signaling pathway and adrenergic signaling transduction pathway of myocardial cells. The results of network topology analysis showed that the key components of anti-AMI of Corydalis Herba might be tetrahydropalmatine, etrahydrocolumbamine, N-trans-feruloyloctopamine, N-cis-p-coumaroyloctopamine, N-trans-p-coumaroylnoradrenline and N-trans-p-coumaroyloctopamine, and their core targets might be CDH23, SCN4 B and NFASC. The results of molecular docking showed that the key components of Corydalis Herba had stable binding activity with the core targets. This study provides reference for further elucidation of the pharmacological effects of Corydalis Herba against AMI, subsequent clinical application, and development.

An immune-stimulating proteoglycan from the medicinal mushroom Huaier up-regulates NF-κB and MAPK signaling via Toll-like receptor 4.

Trametes robiniophila Murr. (Huaier) is a mushroom with a long history of use as a medicinal ingredient in China and exhibits good clinical efficacy in cancer management. However, the antitumor components of Huaier and the underlying molecular mechanisms remain poorly understood. Here, we isolated a proteoglycan with a molecular mass of ∼5.59 × 104 Da from Huaier aqueous extract. We named this proteoglycan TPG-1, and using FTIR and additional biochemical analyses, we determined that its total carbohydrate and protein compositions are 43.9 and 41.2%, respectively. Using biochemical assays and immunoblotting, we found that exposing murine RAW264.7 macrophages to TPG-1 promotes the production of nitric oxide (NO), tumor necrosis factor α (TNFα), and interleukin-6 (IL-6) through Toll-like receptor 4 (TLR4)-dependent activation of NF-κB and mitogen-activated protein kinase (MAPK) signaling. Of note, the TPG-1 treatment significantly inhibited the tumorigenesis of human hepatoma HepG2 cells likely at least in part by increasing serum levels of TNFα and promoting leukocyte infiltration into tumors in nude mice. TPG-1 also exhibited good antitumor activity in hepatoma H22-bearing mice and had no obvious adverse effects in these mice. We conclude that TPG-1 exerts antitumor activity partially through an immune-potentiating effect due to activation of the TLR4-NF-κB/MAPK signaling cassette. Therefore, TPG-1 may be a promising candidate drug for cancer immunotherapy. This study has identified the TPG-1 proteoglycan as an antitumor agent and provided insights into TPG-1's molecular mechanism, suggesting a potential utility for applying this agent in cancer therapy.

[Advances on terpenoids from genus Syringa].

Syringa plants are of important value in ornamental, economic and medical fields. The terpenoids in Syringa plants mainly include iridoids, sesquiterpenoids, and triterpenoids, most showing activities such as cardioprotective, neuroprotective, hypoglycemic, anti-flu virus, anti-bacterial, anti-inflammatory, and anti-oxidation effects. Among the above active compounds, sesquiterpenoids have attracted increasing attention. In this review, the phytochemical and pharmacological activities of Syringa terpenoids were summarized in order to provide an overview for further research and development of Syringa plants.

[Microscopic histochemical comparison during mountain-agarwood formation].

Mountain-agarwood plays an important role in ethnic medicine in China for its pharmaceutical value. Modern pharmacological researches demonstrated that mountain-agarwood was effective for its anti-myocardial ischemia, antibacterial, anti-inflammatory, antitumor and analgesic effects. Mountain-agarwood derives from the peeled roots, stems or twigs of Syringa pinnatifolia which belongs to Syringa genus. It often depends on the purple substance and fragrance to estimate the formation of mountain-agarwood. However, the mechanism of mountain-agarwood formation has not been reported. To observe the microcosmic change in the process during the formation of mountain-agarwood, this study described the microscopic and histochemical characteristics of mountain-agarwood formation through histochemical staining. Our results showed that a significant difference of the distribution of tyloses existed during mountain-agarwood formation. It was observed that inchoate mountain-agarwood had more starch granules and viable cells than mountain-agarwood formed with high level or low level. The amount of polysaccharide and degree of lignification were increased during the mountain-agarwood formation. The results indicated that the mountain-agarwood, which meets the quality requirements for pharmaceutical use, contained the following characteristics: a large amount of purple tyloses in heartwood; yellow-brown tyloses distributing in heartwood and sapwood which were less in the latter; lignification with high level; a few viable cells; lots of polysaccharide and few starch granules in xylem rays cell. This study is aimed to reveal the change of histochemical characteristics during mountain-agarwood formation, and lay the foundation for exploring the mechanism of mountain-agarwood formation.

[Research progress on terpenes and pharmacological effects of Saussurea lappa].

Saussurea lappa originates in India, and now mainly grow in Yunnan, Sichuan and other places in China. It is one of the commonly used traditional herbal medicines in Tibet and other minority regions, with effects in regulating qi to relieve pain and invigo-rating spleen to promote food. It has been used in clinic for gastrointestinal diseases, such as Qi stagnation syndrome of spleen and stomach, diarrhea and tenesmus. More than 200 compounds have been identified from S. lappa. Among them, sesquiterpenoids attracted much attention. In terms of the number of compounds, eudesmanetype is dominant, guaiane and germacranetypes have also been reported frequently. Pharmacological studies have involved extracts, volatile oils and monomeric components represented by dehydrocostus lactone. Anti-tumor, anti-inflammatory and anti-bacterial effects on digestive system have attracted great attention. However, due to the complex sources of S. lappa and widely used in clinical practice, there is few research progress on relevant chemical constituents and pharmacological activities. This paper systematically summarizes terpenes and the pharmacological effects of S. lappa, in order to provide basis for further studies and clinical applications.

[Analysis of bacterial community structure and diversity during mountain-agarwood formation].

As an important substitute for agarwood, mountain-agarwood, belonging to the family Oleaceae, comes from the root, stem and thick branch of Syringa pinnatifolia, which has a wide range of application in Inner Mongolia, China. It has good clinical efficacy in the use of cardiovascular diseases. However, the formation speed of mountain-agarwood is extremely slow, and its cultivated seedlings have low resin content. Therefore, how to speed up the formation of mountain-agarwood and increase the resin content is a hot research topic in this field. In this work, 16 S rDNA amplicon sequencing method was used to systematically analyze the bacterial communities of different samples of mountain-agarwood. Our data revealed that the samples of mountain-agarwood had more obvious species diversity than the ones of non-mountain-agarwood, especially the wild mountain-agarwood samples. By analysis of bacterial community composition and species abundance, Sphingomonas, Modestobacter and unidentified Cyanobacteria genus were three dominant bacterial genera in all samples. In addition, there are two identified genera of dominant bacteria, namely Actinoplanes and Microbacterium in both wild and cultivated mountain-agarwood, by bacterial community composition and species richness analysis. Meanwhile, Roseomonas was the dominant bacterial genus in both wild and cultivated non-mountain-agarwood samples. Our work could provides basic data for exploring the mechanism of the mountain-agarwood formation, and help to exploit resource of endophytic bacteria reasonably.