Three new phenols and one new lignan from Clematis terniflora var. manshurica (Rupr.) Ohwi with their anti-inflammatory activity.

Three undescribed phenols, mandshusica C-E (1-3) and a new lignan, mandshusica F (5), along with six known compounds (4, 6-10) were isolated from the roots and rhizomes of Clematis terniflora var. manshurica (Rupr.) Ohwi. Their structures were elucidated by extensive spectroscopic analysis as well as NMR and ECD calculations. Moreover, the possible biosynthetic pathways of compounds 1-3 were also discussed. All compounds were evaluated for their anti-inflammatory activities in LPS-induced RAW 264.7 cells. Compounds 1, 3, 4 significantly reduced the levels of NO and TNF-α, while compounds 2 and 8 significantly inhibited NO production in LPS-induced RAW264.7 cells.

High Value-Added Application of Natural Products in Crop Protection: Discovery and Exploration of Caffeoyl and Flavonoid Derivatives from Clematis brevicaudata DC. as Novel Insecticide Candidates.

Nine caffeoyl derivatives (1-9), including two new dicaffeoyl glycosides, brevicaudatosides A and B (1 and 2), and six flavonoids (10-15), were identified from overground Clematis brevicaudata DC. Compounds 1 and 13 exhibited significant oral toxicities against Acyrthosiphon pisum Harris with LC50 (half-lethal concentration) values of 0.12 and 0.28 mM, respectively. Meanwhile, compounds 1, 8, 10, 13, and 15 showed remarkable repellent effects against A. pisum with the repellent indexes valued at 1.00 under 50-200 µg/mL at 24 h. Compounds 1 and 8 also displayed moderate antifeedant activities against Plutella xylostella L. The shrunken bodies, especially for wizened cauda, and the ultrastructural damages of microvilli, mitochondrion, nucleus, and endoplasmic reticulum in midgut were toxic symptoms of A. pisum caused by 1 and 13. The inhibition of Chitinase was the main reason for their potent insecticidal activities. This study provided valuable pieces of evidence for the high value-added application of caffeoyl and flavonoid derivatives from C. brevicaudata as novel plant-origin biopesticides for crop protection.

Discovery of New Botanical Insecticides: Identification and Insecticidal Activity of Saponins from Clematis obscura Maxim and Insights into the Stress Response of Acyrthosiphon pisum Harris.

To discover new botanical products-based insecticide candidates, 14 triterpenoid saponins (1-14) including four new ones, obscurosides A-D (1-4), were isolated from Clematis obscura Maxim as potential agrochemicals against Acyrthosiphon pisum Harris and Plutella xylostella (L.). Compounds 1-3 were characterized by a rare ribose substitution at C-3, and 4 was a bidesmoside glycosylated at the rare C-23 and C-28 positions of the oleanane aglycone. Compounds 10 (median antifeeding concentration, AFC50 = 1.10 mg/mL; half-lethal concentration, LC50 = 1.21 mg/mL) and 13 (AFC50 = 1.09 mg/mL, LC50 = 1.37 mg/mL) showed significant insecticidal activities against third larvae of P. xylostella at 72 h. All saponins displayed antifeedant activities against A. pisum with the deterrence index of 0.20-1.00 at 400 µg/mL. Compound 8 showed optimal oral toxicity (LC50 = 50.09 µg/mL) against A. pisum, followed by compounds 1, 5-7, 9, and 14 (LC50 = 90.21-179.25 µg/mL) at 72 h. The shrinkage of the cuticle and the destruction of intestinal structures of microvilli, nucleus, endoplasmic reticulum, and mitochondria were toxic symptoms of 8-treated A. pisum. The significantly declined Chitinase activity in 8-treated A. pisum with an inhibition rate of 79.1% at LC70 (70% lethal concentration) could be the main reason for its significant oral toxicities. Molecular docking revealed favorable affinities of compounds 1 and 8 with group I Chitinase OfChtI (Group I Chitinase from Ostrinia furnacalis) through conventional hydrogen bonds and alkey/π-alkey interactions by different patterns. These results will provide valuable information for the development of novel botanical pesticides for the management of insect pests, especially against A. pisum.

Phenolic glycosides and indole alkaloids isolated from the roots and rhizomes of Clematis chinensis and their anti-inflammatory activity.

Six undescribed compounds, including three phenolic glycosides (1-3) and three indole alkaloids (4-6), together with ten known alkaloids (7-16) and three known phenolic glycosides (17-19), were isolated from 70% EtOH aqueous extracts of the roots and rhizomes of Clematis chinensis Osbeck. The structures were elucidated by NMR, HRESIMS and X-ray diffraction spectroscopies. The anti-inflammatory activity of these compounds was evaluated, and twelve compounds showed significant inhibitory activity against TNF-α with an inhibition ratio from 47.87% to 94.70% at a dose of 10 µM. Compound 7 exhibited significant inhibitory activity against TNF-α and IL-6 with IC50 values of 3.99 µM and 2.24 µM, respectively. Compound 8 displayed potent anti-inflammatory activity against mouse ear edema induced by croton oil. A mechanistic study suggested that compounds 7 and 8 decreased the activation of the NF-κB signaling pathway to reduce the secretion of inflammatory factors in LPS-induced RAW 264.7 cells.

Integrated strategy for the screening of cyclooxygenase-2 inhibitors from triterpenoid saponins in Clematis tangutica.

INTRODUCTION: Screening of novel cyclooxygenase-2 (COX-2) inhibitors from complex natural products is not an easy task. OBJECTIVES: To establish an efficient and feasible strategy for screening COX-2 inhibitors from triterpenoid saponins (TPSs) in Clematis tangutica. METHODS: Taking TPSs in C. tangutica as example, an optimized macroporous resin (MR) method was established for the enrichment of TPSs. High-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOFMS) was performed to establish the phytochemical profiling of TPSs. Molecular docking was performed to predict the ligand-target interactions and discover the active substances. Chemometric techniques were performed to visualize the structure-effect relationships. High-speed countercurrent chromatography and preparative HPLC were performed to prepare the targets. In vitro activity experiment of COX-2 was performed to verify the virtual screening results. RESULTS: TPSs in C. tangutica were well enriched with the recovery rate of (80.22 ± 2.37)%. Thirty-four kinds of TPSs of oleanane type were deduced by HPLC-QTOFMS. Five TPSs of clematangoside C, clematangoside D, clematangoticoside J, hederoside H1 , and hederasaponin B showed stronger binding abilities with COX-2. The structure with more sugar groups at C-28 may be more conducive to the combination with COX-2. Targets were prepared with purities all above 98%. The IC50 values of target TPSs were 6.03 ± 0.24, 12.44 ± 0.15, 9.36 ± 0.19, 4.78 ± 0.13, and 2.59 ± 0.11 µmol/L, respectively. CONCLUSION: The integrated strategy using MR, HPLC-QTOFMS, molecular docking, chemometrics, target preparation, and in vitro verification was feasible for rapidly screening COX-2 inhibitors from TPSs in C. tangutica.

Molecular characterization of a feruloyl-CoA 6'-hydroxylase involved in coumarin biosynthesis in Clematis terniflora DC.

Coumarin is an important secondary metabolite that affects plant physiology. It is a lactone of cis-o-hydroxycinnamic acid and widely exists in medicinal plants. Clematis terniflora DC. is a plant belonging to Ranunculaceae and is rich in variety of coumarins. Feruloyl-CoA 6'-hydroxylase has been reported as a key enzyme in the formation of coumarin basic skeleton only in some common plants, however, its evidence in other species is still lacking especially for the biosynthesis of coumarins in C. terniflora. In the present study, we identified a feruloyl-CoA 6'-hydroxylase CtF6'H in C. terniflora, and functional characterization indicated that CtF6'H could hydroxylate feruloyl-CoA to 6-hydroxyferuloyl-CoA. Furthermore, the expression level of CtF6'H was differed among different tissues in C. terniflora, while under UV-B radiation, the level of CtF6'H was increased in the leaves. Biochemical characteristics and subcellular location showed that CtF6'H was mainly present in the cytosol. The crystal structure of CtF6'H was simulated by homology modeling to predict the potential residues affecting enzyme activity. This study provides the additional evidence of feruloyl-CoA 6'-hydroxylase in different plant species and enriches our understanding of biosynthetic mechanism of coumarin in C. terniflora.

The multi-omics and analysis to reveal thermal processing enhanced anti-rheumatoid arthritis efficacy of Radix Clematidis in rats.

Radix Clematidis (RC) is the roots and rhizomes of Clematis chinensis Osbeck, which has potent effects for expelling wind and dispelling dampness. Processing RC with yellow wine is a traditional processing method. This study aimed to investigate thermal and yellow wine processing influences on potential effective components of RC and its anti-rheumatoid arthritis enhancement mechanisms. Different thermal and wine processing were adopted to get different RC samples. Scanning electron microscope and mercury intrusion porosimetry were used to measure fractal parameters of pore structure. Based on ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS), main constituents were identified and quantified. Besides, the correlation between fractal parameters and main constituents was investigated. The anti-rheumatoid arthritis effect was researched in adjuvant-induced arthritis (AIA) rats. The levels of inflammatory cytokine were determined with ELISA kits. Non-targeted serum metabolomics was performed with UPLC-QTOF/MS. 35 compounds were identified in RC, mainly triterpenoid saponins, also including organic acids and lignanoids. The extraction yield of four active triterpenoid saponins significantly increased because looser tissue and wider pore size distribution. Fractal dimension and total surface area significantly increased while total porosity and total volume decreased. In AIA rats, thermal and wine processed RC could markedly inhibit inflammatory cytokines IL-6, IL-1ß, TNF-α, and VEGF. Besides, tryptophan and lipid metabolism disorders were ameliorated. Thermal and yellow wine treatments engendered complex pore structure to increase the contents of four active triterpenoid saponins of RC, leading to greater anti-rheumatoid arthritis efficacy.

New triterpenoid saponins from the whole plants of Clematis heracleifolia.

Three new triterpenoid saponins, heracleifolianosides A-C (1-3), together with seven known compounds (4-10), were isolated from the whole plants of Clematis heracleifolia. Moreover, three new secondary saponins (1a, 2a and 3a), two known secondary metabolites (5a and 7a) were obtained by alkaline hydrolysis. Their structures were elucidated by extensive spectroscopic analysis and chemical evidences. The cytotoxicity of eight native saponins and five prosapogenins against human breast tumor MDA-MB-231 and gastric carcinoma SGC-7901 cell lines were evaluated by MTT method. Remarkably, the prosapogenin monodesmosidic saponin 7a showed significant cytotoxicity against MDA-MB-231 or SGC-7901 cell lines with IC50 values in the range of 6.05-6.32 µmol/L. It is suggested that it might be a feasible way to change the inactive bisdesmosic triterpenoid saponins to active monodesmosic saponins by a simple procedure of alkaline hydrolysis.

Thermal and wine processing enhanced Clematidis Radix et Rhizoma ameliorate collagen â ¡ induced rheumatoid arthritis in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Clematidis Radix et Rhizoma, a kind of traditional Chinese medicine, is derived from Clematis chinensis Osbeck, Clematis hexapetala Pall. and Clematis manshurica Rupr. This herb shows great effects on expelling wind and dispelling dampness in ancient and it has anti-inflammatory and analgesic activity in modern clinical application. AIM OF THE STUDY: This experiment aimed to research anti-rheumatoid arthritis effect of crude and wine processed RC based on glycolysis metabolism to provide new ideas treating RA. MATERIALS AND METHODS: Network pharmacology was applied to preliminarily forecast the potential pathways of common targets of RC and RA. RAW264.7 macrophages were induced by LPS, NO production, glucose uptake, lactate production, ROS and MMP were detected as instructions in vitro. ELISA was used to measure the content of HK2, PKM2 and LDHA involving in glycolysis process. Gut microbiota was analyzed by 16S rRNA gene amplicon sequencing in CIA rats. RESULTS: Crude and wine processed RC had good anti-inflammatory effect by reducing NO in RAW264.7 macrophages and ameliorating inflammatory infiltration and cartilage surface erosion in CIA rats. Whether in LPS-induced macrophages or CIA rats, crude and wine processed RC could inhibit glycolysis by down-regulating the expression of PKM2, causing less glucose uptake and lactic acid, which lead to less ROS and higher MMP to normal. PI3K-AKT and HIF-1α pathways were deduced to possibly play a crucial part in controlling glycolysis metabolism by network pharmacology analysis. Besides, it was displayed that Firmicutes and Bacteroidetes were prominent gut microbiota in CIA rats feces. CC-H and PZ-H groups could both increase the relative abundance of Firmicutes and decrease Bacteroidetes. These microbiota also played a role in RA pathological process via involving in energy metabolism, carbohydrate metabolism and immune system. CONCLUSION: Crude and wine processed RC have a good influence in ameliorating rheumatoid arthritis by inhibiting glycolysis and modulating gut microbiota together.

Two new terpenes from the aerial parts of Clematis chinensis Osbeck.

Two new acyclic sesquiterpenoids (1-2) and fourteen known monocyclic monoterpenoids (3-16) were isolated from the aerial parts of Clematis chinensis Osbeck. All compounds were isolated from C. chinensis for the first time. The structures of all compounds were characterized by spectroscopic methods (1 D, 2 D NMR and HRESIMS). In-vitro cytotoxic activity against two human cancer cell lines (MGC-803 and Ishikawa) of all the compounds were evaluated by CCK-8 assay.

A new cyclopeptide alkaloid from Clematis Florida.

One new 14-membered ring cyclopeptide alkaloid, plenane A (1), along with six known compounds (2-7), was isolated from the roots of Clematis florida. Their structures were elucidated by means of NMR spectroscopic analysis and mass spectrometry. In addition, their anti- inflammatory effects on lipopolysaccharide-induced RAW264.7 macrophages were evaluated in vitro. The compounds 1, 2 and 6 exhibited potent indirect inhibitory effects, with IC50 values of 40.92, 22.88 and 6.32 µM, respectively.

Uses, chemical compositions, pharmacological activities and toxicology of Clematidis Radix et Rhizome- a Review.

ETHNOPHARMACOLOGICAL RELEVANCE: Clematis chinensis Osbeck (C. chinensis), Clematis hexapetala Pall (C. hexapetala) and Clematis terniflora var. mandshurica Rupr (C. mandshurica) are collectively referred to as Clematidis Radix et Rhizome (CRR) in China. CRR is widely distributed in China, which is used as a traditional Chinese medicine to treat rheumatic arthralgia, limb numbness, tendon constriction and inconvenience in flexion and extension. AIMS OF THIS REVIEW: This review systematically summarized the research progress on uses, chemical components, pharmacological activities and toxicology of CRR, listed the chemical structures of main compounds for clarifying the differences in chemical compositions. Meanwhile, the review will provide a theoretical and practical basis for the further research and development of CRR. MATERIALS AND METHODS: The available information on CRR was collected using published materials and electronic databases, including ancient and modern books, Chinese Pharmacopoeia, Ph.D. and M. Sc. dissertations, CNKI, SciFinder, WanFang data, PubMed, ScienceDirect and Web of Science. The starting and ending years of references is 1965-2020, the search strategy was conducted by key words such as uses, chemical components, pharmacology and toxicology of CRR. RESULTS: Up to now, CRR has been used to treat various diseases/disorders, such as relieving rheumatism pain, treating cervical spondylopathy and scapulohumeral periarthritis, treating hepatic carcinoma and gastrointestinal, etc. In addition, more than 200 compounds have been isolated from the three plant species of Clematidis. Moreover, the crude extracts and isolated compounds of CRR have been reported to have a wide range of pharmacological activities, such as anti-inflammatory, anti-tumor, antimicrobial and antioxidant activities, etc. Toxicity studies have shown that CRR can cause oral burning, swelling, abdominal pain or severe diarrhea, difficulty breathing, dilated pupils, renal tissue structural changes, and severe death. CONCLUSIONS: Researches in recent years mainly focused on C. chinensis and C. mandshurica, while there are a few reports on the pharmacological studies of C. hexapetala. Therefore, it is necessary to conduct further research on C. hexapetala. Meanwhile, it is important to pay attention to pursue research on the similarities and differences between the three plant species of Clematidis to find their respective advantages and make rational use of CRR. In addition, there is no report on the mechanism of toxicity research, which needs more attention.

Sesquiterpenoids, phenolic and lignan glycosides from the roots and rhizomes of Clematis hexapetala Pall. and their bioactivities.

Approximately 17 compounds were isolated from a 60% EtOH aqueous extract of the roots and rhizomes of Clematis hexapetala Pall., including three new guaianolide sesquiterpenoids with 5/7/5-fused rings and 3S-configuration (1-3), five new prenylated tetra-substituted phenolic glycosides (4-8) with 6/6-fused 9H-benzopyran skeleton (5) and 6/7-fused 7,10-dihydro-benzoxepin skeleton (6-8), one new isoferulyl glucoside (9), two new furofuran lignan diglucosides (10-11), and six known compounds. The chemical structures of the new compounds were elucidated via spectroscopic data and electronic circular dichroism (ECD) analyses in combination with a modified Mosher's method. The possible biosynthetic relationships of prenylated tetra-substituted phenols were postulated. In the in vitro assays, compound 16 exhibited moderate TNF-α secretion inhibitory activity with IC50 value of 3.419 µM. Compounds 14-16 displayed potent PTP1B enzymatic inhibitory activities with inhibition ratios of 48.30-86.00%. And compound 16 showed significant PTP1B enzymatic inhibition with IC50 value of 4.623 µM.

Effect of total flavones of Clematis filamentosa Dunn on the oxLDL-induced injury of vascular smooth muscle cells by regulating miR-455-5p.

This experiment was conducted to investigate whether total flavones of Clematis filamentosa Dunn affect the inflammatory response and apoptosis of vascular smooth muscle cells induced by oxidized low-density lipoprotein (oxLDL) by regulating microRNA-455-5p (miR-455-5p). 50 mg/mL oxLDL was performed to stimulate the injury of vascular smooth muscle cells, and the total flavones of Clematis filamentosa Dunn were added at concentrations of 75, 150, and 300 µg/mL. The expressions of inflammatory factors IL-1ß and TNF-α were analyzed by ELISA, the apoptosis was evaluated by flow cytometry, the expression of Bcl-2 and Bax was determined by western blot, and the real-time fluorescence quantitative PCR (qRT-PCR) was applied to detect miR-455-5p expression. MiR-455-5p mimic was transfected into vascular smooth muscle cells and then induced injury with oxLDL; miR-455-5p inhibitor was transfected into vascular smooth muscle cells and treated with oxLDL and 300 µg/mL total flavones of Clematis filamentosa Dunn. The above methods were employed to investigate the inflammatory response and apoptosis of cells. The total flavones of Clematis filamentosa Dunn significantly inhibited the expression of IL-1ß, TNF-α, apoptosis rate, Bax protein expression of oxLDL induced vascular smooth muscle cells, and remarkably promoted the expression of Bcl-2 protein and miR-455-5p, which all showed concentration dependence (p<0.05). Overexpression of miR-455-5p reduced IL-1ß, TNF-α expression, apoptosis rate, Bax protein expression, and greatly increased Bcl-2 protein expression in oxLDL injured vascular smooth muscle cells (p<0.05). After interfering with the expression of miR-455-5p, the inhibitory effect of total flavones of Clematis filamentosa Dunn on the expression of IL-1ß, TNF-α, apoptosis, Bax protein expression of oxLDL-induced vascular smooth muscle cells was reversed, and its promotion effect on Bcl-2 protein expression was also reversed. Total flavones of Clematis filamentosa Dunn can reduce oxLDL-induced vascular smooth muscle cell inflammation and inhibit its apoptosis. The mechanism of action is related to the up-regulation of miR-455-5p expression.

Composition and Biosynthesis of Scent Compounds from Sterile Flowers of an Ornamental Plant Clematis florida cv. 'Kaiser'.

Clematis florida is a popular ornamental vine species known for diverse colors and shapes of its flowers but not for scent. Here we investigated the composition and biosynthesis of floral scent in 'Kaiser', a fragrant cultivar of C. florida that has sterile flowers. Volatile profiling revealed that flowers of 'Kaiser' emit more than 20 compounds, with monoterpenes being most abundant. Among the three floral organs, namely sepals, transformed-petals, and ovaries, ovaries had the highest rates of total volatile emission. To determine the molecular mechanism underlying floral scent biosynthesis in 'Kaiser', we sequenced a flower transcriptome and searched the transcriptome for terpene synthase genes (TPSs), which are key genes for terpene biosynthesis. Among the TPS genes identified, three were putative intact full-length genes and were designated CfTPS1, CfTPS2, and CfTPS3. Phylogenetic analysis placed CfTPS1, CfTPS2, and CfTPS3 to the TPS-g, TPS-b, and TPS-a subfamily, respectively. Through in vitro enzyme assays with Escherichia coli-expressed recombinant proteins, both CfTPS1 and CfTPS2 were demonstrated to catalyze the conversion of geranyl diphosphate to linalool, the most abundant constituent of C. florida floral scent. In addition, CfTPS1 and CfTPS2 produced the sesquiterpene nerolidol from (E,E)-farnesyl diphosphate. CfTPS3 showed sesquiterpene synthase activity and produced multiple products in vitro. All three CfTPS genes showed higher levels of expression in sepals than those in transformed-petals and ovaries. Our results show that despite being sterile, the flowers of 'Kaiser' have normal mechanisms for floral scent biosynthesis that make the flowers fragrant.

Apigenin-7-O-ß-d-(6″-p-coumaroyl)-glucopyranoside reduces myocardial ischaemia/reperfusion injury in an experimental model via regulating the inflammation response.

Context: Traditionally, Clematis tangutica Korsh. (Ranunculaceae) is used as a Tibetan herb for treating indigestion and blood stasis in China. Recently, a flavonoid glycoside, apigenin-7-O-ß-d-(6″-p-coumaroyl)-glucopyranoside (APG), was isolated from the whole plant of C. tangutica.Objective: To investigate the cardioprotective effects of APG against myocardial ischaemia/reperfusion injury (MI/RI) and the possible mechanism.Materials and methods: Animals were subjected to 30 min/3 h MI/RI model. At the end of reperfusion, infarct size (IS), histopathology, serum levels CK-MB, LDH, TNF-α, IL-6 and MPO activities were detected. Phospho-IκB-α, ICAM-1 and NF-κB were assessed in vivo. Neonatal rat cardiomyocytes were pre-treated with or without APG, followed by stimulation with 8 h/2 h oxygen and glucose deprived/reoxygenation (OGD/R) model. Cell viability, LDH and cardiomyocyte apoptosis were assessed. The expression levels of phospho-IκB-α and NF-κB were measured in vitro.Results: Treatment with APG significantly reduced the following indicators in vivo (p < 0.05): (1) the IS (16.2%); (2) morphology score (1.67); (3) myocardial injury enzymes: CK-MB (26.2 ng/mL) and LDH (688 U/L); (4) pro-inflammatory cytokines: TNF-α (31.5 pg/mL) and IL-6 (163.8 pg/mL); (5) MPO activity (2.75 U/mg); (6) expression levels of phospho-IκB-α (0.47), NF-κB (2.87) and ICAM-1 (10.2). Moreover, treatment with APG also remarkably (p < 0.05) attenuated the following indicators in vitro: (1) LDH level (206 U/L); (2) cardiomyocyte apoptosis; (3) phospho-IκB-α (1.37) and NF-κB (2.50).Conclusions: APG possesses protective effects against MI/RI injury in rats and OGD/R-induced injury in cardiomyocytes by suppressing translocation of NF-κB and reducing inflammatory response; consequently, APG is helpful for treatment of ischaemic heart disease.

Antagonizing Effects of Clematis apiifolia DC. Extract against Benzo[a]pyrene-Induced Damage to Human Keratinocytes.

Background. Benzo[a]pyrene (B[a]P), a polycyclic aromatic hydrocarbon present in the atmosphere, has cytotoxic and carcinogenic effects. There have been no reports to demonstrate involvement of Clematis apiifolia DC. extract (CAE) in B[a]P-induced effects. This study was conducted to investigate the effect of CAE on B[a]P-induced effects and to elucidate its mechanism of action in HaCaT human keratinocytes. CAE inhibited aryl hydrocarbon receptor (AhR) signaling by decreasing both XRE reporter activity and expression of cytochrome P450 1A1 (CYP1A1) induced by B[a]P treatment in HaCaT cells. We also found that B[a]P-induced nuclear translocation of AhR and production of reactive oxygen species (ROS) and proinflammatory cytokines were attenuated by CAE treatment. CAE treatment suppressed B[a]P-induced phosphorylation of Src (Tyr416). In addition, dasatinib, a Src inhibitor, also inhibited B[a]P-induced nuclear translocation of AhR, similar to CAE treatment. In addition, CAE activated antioxidant response element (ARE) signaling by increasing ARE luciferase reporter activity and expression of ARE-dependent genes such as nuclear factor (erythroid-derived 2)-like 2 (Nrf2), NAD(P)H dehydrogenase [quinone] 1 (NQO1), and heme oxygenase-1 (HO-1). Nuclear translocation of Nrf2 by CAE was demonstrated by Western blot analysis and immunocytochemistry. The effects of CAE on ARE signaling were attenuated by knockdown of the Nrf2 gene. Inhibition of AhR signaling and activation of antioxidant activity by CAE operated in a reciprocally independent manner as evidenced by AhR and Nrf2 siRNA experiments. These findings indicate that CAE exerts protective effects against B[a]P by inhibiting AhR signaling and activating Nrf2-mediated signaling, suggesting its potential in protection from harmful B[a]P-containing pollutants.

Saponins from Clematis mandshurica Rupr. regulates gut microbiota and its metabolites during alleviation of collagen-induced arthritis in rats.

Gut microbiota and their metabolites (short-chain fatty acids, SCFAs) are associated with the pathogenesis of rheumatoid arthritis (RA). Total Clematis triterpenoid saponins (CTSs) prepared from Clematis mandshurica Rupr. possess therapeutic benefits for arthritic diseases. However, the poor pharmacokinetic properties of CTSs have obstructed the translation of these natural agents to drugs. Here, we examined the effects of CTSs on arthritis symptoms, gut microbiota and SCFAs in rats with collagen-induced arthritis (CIA). Our results showed that the arthritis index scores of CIA rats treated with CTSs were significantly lower than those of the model group. Most importantly, CTSs moderated gut microbial dysbiosis and significantly downregulated the total SCFA concentration in CIA rats. Compared to the control group, CTSs treatment have no significant side effects on the gut microbiota and SCFA metabolism in normal rats. Two differential analyses (LEfSe and DESeq2) were combined to study the details of the changes in gut microbiome, and twenty-four marker taxa at the genus level were identified via a comparison among control, model and CIA rats treated with high doses of CTSs. In particular, the mostly significantly increased gram-negative (G-) and decreased gram-positive (G+) genera in CIA rats were well restored by CTSs. The observed SCFA concentrations demonstrated that CTSs tend to maintain the balance of the gut microbiota. The data presented herein suggest that CTSs could ameliorate arthritis-associated gut microbial dysbiosis and may be potential adjuvant drugs that could provide relief from the gastrointestinal damage caused as a side effect of commonly used drugs.

A new indole-type alkaloid from the roots of Clematis florida var. plena.

One new indole-type alkaloid, α-L-rhamnopyranosyl-(1→6)-ß-D- glucopyranosyl 6-methoxy-3-indolecarbonate (1), together with three known alkaloids (2-4), one aromatic acid (5) and five known saponins (6-10), was isolated from the roots of Clematis florida var. plena. Their structures were established by NMR spectroscopic analysis and acid hydrolysis. In in vivo anti-inflammatory activity, n-butanol extract was found to be potent against ear edema in mice, with inhibition rate of 48.7% at a dose of 800 mg/kg. Furthermore, compounds 8 and 9 obtained from the n-butanol extract exhibited significant anti-inflammatory activities with inhibition rates of 50.9% and 54.7% at a dose of 200 mg/kg.

Phenolic compounds from the aerial parts of Clematis viticella L. and their in vitro anti-inflammatory activities.

Phytochemical investigations on the EtOH extract of Clematis viticella led to the isolation of six flavonoid glycosides, isoorientin (1), isoorientin 3'-O-methyl ether (2), quercetin 7-O-α-L-rhamnopyranoside (3), quercetin 3,7-di-O-α-L-rhamnopyranoside (4), manghaslin (5) and chrysoeriol 7-O-ß-D-glucopyranoside (6), one phenylethanol derivative, hydroxytyrosol (7), along with three phenolic acids, caffeic acid (8), (E)-p-coumaric acid (9) and p-hydroxybenzoic acid (10). The structures of the isolates were elucidated on the basis of NMR and HR-MS data. All compounds were isolated from C. viticella for the first time. Compounds 7 and 8 showed significant anti-inflammatory activity at 100 µM by reducing the release of NO in LPS-stimulated macrophages comparable to positive control indomethacin. Compounds 3 and 7 exhibited anti-inflammatory activity through lowering the levels of TNF-α while 1, 3 and 5 decreased the levels of neopterin better than the positive controls.