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.

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.

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.

Inhibitory effects of Clematis orientalis aqueous ethanol extract and fractions on inflammatory markers in complete Freund's adjuvant-induced arthritis in Sprague-Dawley rats.

Clematis orientalis Linn has long been used as ethnopharmacy for the treatment of arthritis. This study is intended to evaluate the curative efficacy of Clematis orientalis in treating polyarthritis in rats. Aqueous ethanolic extract and fractions (hexane, butanol and aqueous) were administered orally at 200 mg/kg for 28 days after CFA immunization. Paw swelling, paw diameter, arthritic score, body weight, hematological parameters, radiographic and histological analysis of ankle joints were evaluated. Moreover, levels of various inflammatory markers through RT-PCR and ELISA were measured. DPPH and reducing power assays were used to appraise antioxidant capacity. Qualitative phytochemical analysis, determination of total phenolic and flavonoid contents were also carried out. Aqueous ethanolic extract and fractions significantly (p < 0.001) reduced paw volume, paw thickness and arthritic score and considerably prevented decrease in body weight along with anomalous alterations in hematological parameters in comparison with arthritic control. X-ray and histological examination revealed no significant structural changes in ankle joints of treated rats. Expression levels of IL-1ß, TNF-α, IL-6, COX-2 and NF-Kß were significantly (p < 0.05-0.001) suppressed as well as noteworthy increase in the levels of IL-4 and IL-10 among treated animals has been detected. Overproduction of TNF-α and PGE2 was substantially prevented in animals given different treatments. Aqueous ethanol extract and its fractions demonstrated significant and concentration-dependent antioxidant potential. In general, among fractions aqueous fraction exhibited a greater anti-arthritic effect. Phytochemical analysis of aqueous fraction confirmed the presence of flavonoids and glycosides, 215.29 mgGAE/ml phenolic content and 633.03 µgQE/ml flavonoid content. Thus, we suggest Clematis orientalis as a potent strategy for the treatment of rheumatoid arthritis.

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.

Tunisian Clematis flammula Essential Oil Enhances Wound Healing: GC-MS Analysis, Biochemical and Histological Assessment.

The aerial part of Clematis flammula (Ranunculaceae) has been traditionally used in the treatment of skin diseases including mycotic infection in the Tunisian traditional medicine. The study was undertaken to extract and determine the essential oil chemical composition of Clematis flammula aerial parts and to assess the potential of anemonin in wound healing on mechanically wounded wistar rats. The essential oil was obtained by hydrodistillation and analyzed by GC-MS. Anemonin was isolated and then incorporated as active in a cream for which the cytotoxicity was evaluated by methyl thiazolyl tetrazolium (MTT)-based colorimetric assay. Then, its potential in wound healing on mechanically wounded wistar rats was assessed. The GC-MS analysis showed that the major compound was protoanemonin (86.74%) which spontaneously dimerised in part to form the anemonin. The wound healing activity of anemonin cream exhibited a non toxic potential of anemonin at a concentration of 25 µg/mL with a cell migration efficiency that reaches more than 80% after 48 hours of treatment. Wound healing efficiency was evaluated by monitoring morphological and skin histological analyses. Comparable wound surface reduction of the group treated by anemonin cream (p ≥ 0.05) when compared to the reference treated group. The skin histological analysis showed the completely wound closure. Antioxidant activity was assessed by the malondialdehyde (MDA) rates and antioxidant enzymes (glutathione peroxidase (GPx) and catalase) determination. The results provided strong support for the effective wound healing activity of anemonin cream, making it a promising candidate as a therapeutic agent in tissue repairing processes.

The protective effects of ethanolic extract of Clematis terniflora against corticosterone-induced neuronal damage via the AKT and ERK1/2 pathway.

Chronic stress induces neuronal cell death, which can cause nervous system disorders including Parkinson's disease and Alzheimer's disease. In this study, we evaluated the neuroprotective effects of Clematis terniflora extract (CTE) against corticosterone-induced apoptosis in rat pheochromocytoma (PC12) cells, and also investigated the underlying molecular mechanisms. At concentrations of 300 and 500 µg/ml, CTE significantly decreased apoptotic cell death and mitochondrial damage induced by 200 µM corticosterone. CTE decreased the expression levels of endoplasmic reticulum (ER) stress proteins GRP78, GADD153, and mitochondrial damage-related protein BAD, suggesting that it downregulates ER stress evoked by corticosterone. Furthermore, our results suggested that these protective effects were mediated by the upregulation of p-AKT and p-ERK1/2, which are involved in cell survival signaling. Collectively, our results indicate that CTE can lessen neural damage caused by chronic stress. [BMB Reports 2018; 51(8): 400-405].

Cytotoxic Activities of Total Saponins from Plena Clematis on Human Tumor Cell Lines In Vitro.

OBJECTIVE: To investigate the anti-proliferative effects of saponins prepared from Plena Clematis (PC) cultured in Fujian Province, China on 4 human tumor cell lines and its possible anti-tumor mechanism. METHODS: The growth inhibition assays of saponins on human esophageal squamous carcinoma cell line (EC9706), human hepatoma cell line (HepG-2), human oral cancer cell line (KB) and human gastric cancer cell line (BGC-823) were evaluated in vitro by thiazolyl blue (MTT) method. The inhibitory effects on EC9706 treated with different concentrations of saponins (15.62, 31.25, 62.50, 125, 250 and 500 µg/mL) were performed in vitro by MTT method. The morphology and nuclear staining with acridine orange/ethidium bromide of EC9706 cells treated with saponins were illustrated under an inverted phase fluorescence microscope. The apoptotic effects of saponins were further evaluated by annexin-V/propidium iodide dual staining experiment to examine the occurrence of phosphatidylserine externalization onto the cell surface by a flflow cytometer. RESULTS: MTT assay showed that the saponins could inhibit the proliferation of 4 tumor cell lines. Among them, the maximum inhibition rate of 73.1% was detected in EC9706 cells at the saponins concentration of 250 µg/mL for 24 h. Further investigation indicated that the saponins induced EC9706 cells apoposis. The EC9706 cells presented apoptotic characteristics when treated with saponins, including that the morphologies of EC9706 cells were appeared round-shaped with higher refraction, and the cell nuclear stained orange with EB after 250 µg/mL saponins exposure. The flow cytometry analysis results showed that the induction of cell cycle arrest in apoptotic system may participate in the anti-proliferative activity of saponins on EC9706 cells. CONCLUSION: The saponins from PC exhibited significant cytotoxicity against human EC9706, KB, BGC-823, and HepG-2 cells and might be beneficial to development of ethnic pharmaceutical plant for potential anti-tumor drugs.

Novel triterpene saponins isolated from Clematis mandshurica and their inhibitory activities on NO production.

Four new triterpene saponins, mandshunosides F-I (1-4), together with five known compounds (5-9), were isolated from the roots and rhizomes of Clematis mandshurica. Their structures were elucidated on the basis of spectroscopic evidences and hydrolysis products. Bisdesmosidic saponin (3-9) showed modest suppression of NO production with the inhibition ratios in the range of 51.3%- 64.6% at 50 µmol·L-1, whereas monodesmosidic saponins with a free carboxyl group at C-28 (1 and 2) showed potent inhibitory activities with IC50 values being 12.7 and 8.3 µmol·L-1, respectively.

Antioxidant potential assessment of phenolic and flavonoid rich fractions of Clematis orientalis and Clematis ispahanica (Ranunculaceae).

The antioxidant activities of crude extract fractions using Hexane, Chloroform, Ethyl Acetate, Butanol and Water of Clematis orientalis and Clematis ispahanica were investigated. 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay and the ferric reducing/antioxidant potential (FRAP) were used to evaluate the antioxidant capacity. The total phenolics were found to be 4.37-9.38 and 1.32-11.37 mg gallic acid equivalents (GAE)/g in different fractions for C. orientalis and C. ispahanica, respectively. The ethyl acetate fraction of C. orientalis and chloroform fraction of C. ispahanica showed the highest DPPH and FRAP activities at a concentration of 300 µg/mL. The predominant phenolic compounds identified by HPLC in C. orientalis were Resorcinol (603.5 µg/g DW) in chloroform fraction and Ellagic acid (811.7 µg/g DW) in chloroform fraction of C. ispahanica.

Anti-rheumatoid arthritis effects of traditional Chinese herb couple in adjuvant-induced arthritis in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Clematis chinensis Osbeck / Notopterygium incisum Ting ex H, T-Chang (CN) is a traditional Chinese herb couple with prominent efficacy. The herb couple has been commonly used for clinical treatment of arthralgia syndrome ("Bi Zheng" in Chinese) for centuries in China, including rheumatic arthritis, osteoarthritis and gout in modern medicine. AIM OF THE STUDY: To evaluate the anti-arthritic effect of CN herb couple in a rat model of rheumatoid arthritis (RA). MATERIALS AND METHODS: Rats were divided randomly into six groups with eight each. Adjuvant-induced arthritis (AIA) model was established by intradermal injection of complete Freund's adjuvant (CFA). Rats were treated orally with different dosages of CN (0.7g/kg, 2.1g/kg, 6.3g/kg) from day 16 till day 40. Ibuprofen (50.4mg/kg) served as a positive control. Spontaneous activity, body weight, paw swelling, and arthritis index (AI) were monitored throughout drug treatment. Then serum levels of tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), and vascular endothelial growth factor (VEGF) were determined by enzyme linked immunosorbent assay (ELISA) kits. In addition, histopathological examination and immunohistochemistry were used to assess the severity of arthritis. RESULTS: Three dosage of CN significantly ameliorated symptoms of RA via increasing body weight as well as reducing paw swelling (at dose of 6.3g/kg, p<0.01) in AIA rats. An extremely significant reduction of AI (p<0.001) was also observed with treatment of CN (6.3g/kg) compared with model group. In parallel, treatment of CN significantly down-regulated levels of TNF-α, IL-6, and VEGF both in serum (p<0.01) and in joint synovial compared with model rats. And histopathology revealed noticeable reduction in synovial hyperplasia, cartilage damage, and inflammatory infiltration by CN treatment, especially at dose of 6.3g/kg. CONCLUSIONS: To conclude, all results suggest that CN possesses evident anti-arthritic effects in AIA rats.

Dose-response characteristics of Clematis triterpenoid saponins and clematichinenoside AR in rheumatoid arthritis rats by liquid chromatography/mass spectrometry-based serum and urine metabolomics.

Clematidis Radix et Rhizoma is a traditional Chinese medicine widely used for treating arthritic disease. Clematis triterpenoid saponins (TS) and clematichinenoside AR (C-AR) have been considered to be responsible for its antiarthritic effects. However, the underling mechanism is still unclear because of their low bioavailability. To address of this issue, metabolomics tools were performed to determine metabolic variations associated with rheumatoid arthritis (RA) and responses to Clematis TS, C-AR and positive drug (Triptolide, TP) treatments. This metabolomics investigation of RA was conducted in collagen-induced arthritis (CIA) rats. Liquid chromatography/mass spectrometry and multivariate statistical tools were used to identify the alteration of serum and urine metabolites associated with RA and responses to drug treatment. As a result, 45 potential metabolites associated with RA were identified. After treatment, a total of 24 biomarkers were regulated to normal like levels. Among these, PC(18:0/20:4), 9,11-octadecadienoic acid, arachidonic acid, 1-methyladenosine, valine, hippuric acid and pantothenic acid etc, were reversed in Clematis TS and C-AR groups. Tetrahydrocortisol was regulated to normal levels in Clematis TS and TP groups, while 3,7,12-trihydroxycholan-24-oic acid was regulated in C-AR and TP groups. Biomarkers like citric acid, p-cresol glucuronide, creatinine, cortolone were reversed in TP group.

Development and validation of a quantification method for oleanolic acid and hederagenin in rat plasma: application to the pharmacokinetic study.

A rapid and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed and validated for simultaneous quantification of oleanolic acid and hederagenin in rat plasma. After the two analytes were extracted with liquid-liquid extraction, chromatographic separation was performed on a C18 column with acetonitrile and water (85:15, v/v) as mobile phase at a flow rate of 0.4 mL/min. Calibration curves exhibited good linearity (r > 0.995) over the ranges of 0.41-82.0 ng/mL for oleanolic acid and 0.32-64.0 ng/mL for hederagenin, respectively. The lower limit of quantifications (LLOQs) in plasma were 0.41 ng/mL for oleanolic acid and 0.32 ng/mL for hederagenin. The established LLOQs were within the concentration needed for the assay in plasma, which met the requirements to evaluate their pharmacokinetics of oleanolic acid and hederagenin. This developed assay was successfully applied in the pharmacokinetic study of oleanolic acid and hederagenin in rats after oral administration of Rhizoma Clematidis extract.

Cytotoxic activities of flavonoids from a traditional Mongolian medicinal herb Clematis aethusifolia Turcz.

In the course of our search for antitumour constituents from the traditional Mongolian medicinal herb Clematis aethusifolia Turcz., 11 flavonoids were isolated for the first time from the dried aerial parts of the plant by flash C18 column chromatography, Sephadex LH-20 and reversed phase preparative HPLC. The planar structures of these flavonoids were established based on 1D and 2D NMR and high-resolution mass spectrometry. Compounds 1, 2, 4 and 5 showed moderate cytotoxicity against a panel of five human solid tumour cell lines, including A-375, a human melanoma cell line; SK-OV-3, a human ovarian cancer cell line; A549, a human lung cancer cell line; HCT-15, a human colorectal adenocarcinoma cell line; and SH-SY5Y, a human neuroblastoma cell line (with IC50 values of 20-70 µM). The obtained cytotoxic apigenin and its derivatives may be useful as standard compounds for the quality control of the crude drug and its preparations.

Boehmenan, a Lignan From the Chinese Medicinal Plant Clematis armandii, Inhibits A431 Cell Growth via Blocking p70S6/S6 Kinase Pathway.

Previously, we have shown that boehmenan, a natural product isolated from the dried stem of Caulis clematidis armandii, exhibits various biological activities. The current study investigated the effects of boehmenan on the growth of human epidermoid carcinoma A431 cells. Cell viability and 50% inhibiting concentration (IC50) were assessed by CellTiter-Glo luminescent cell viability assay. Cell cycle arrest was measured by flow cytometry. Intracellular reactive oxygen species production and mitochondrial membrane potential (ΔΨm) collapse were analyzed by a fluorescence spectrophotometer. The activation of epidermal growth factor receptor signaling pathway was evaluated by Western blot. The results showed that boehmenan significantly inhibited the growth of A431 cells (IC50 = 1.6 µM) in a concentration- and time-dependent manner. This compound also blocked cell cycle progression at G2/M phase and modulated mitochondrial apoptosis-related proteins, as evidenced by upregulating p21, cleaved caspase-3, and cleaved poly (ADP-ribose) polymerase protein levels and by downregulating Bcl-2, pro-caspase-9 levels. In addition, boehmenan also markedly induced intracellular reactive oxygen species production and ΔΨm depolarization in a concentration-dependent manner. Furthermore, boehmenan-attenuated epidermal growth factor mediated the phosphorylation of signal transducer and activator of transcription 3 (STAT3), p70 ribosomal protein S6 kinase (p70S6)/S6 in a concentration-dependent manner. Taken together, our results suggest that boehmenan-mediated antiproliferative property in A431 cells was mediated partially by modulation of mitochondrial function and inhibition of STAT3 and p70S6 signal pathways.

Isolation and characterization of bioactive compounds of Clematis gouriana Roxb. ex DC against snake venom phospholipase A2 (PLA2) computational and in vitro insights.

Bioactive compounds were isolated from Clematis gouriana Roxb. ex DC. The compounds were separated, characterized, the structures elucidated and submitted to the PubChem Database. The PubChem Ids SID 249494134 and SID 249494135 were tested against phospholipases A2 (PLA2) of Naja naja (Indian cobra) venom for PLA2 activity. Both the compounds showed promising inhibitory activity; computational data also substantiated the results. The two compounds underwent density functional theory calculation to observe the chemical stability and electrostatic potential profile. Molecular interactions between the compounds and PLA2 were observed at the binding pocket of the PLA2 protein. Further, this protein-ligand complexes were simulated for a timescale of 100 ns of molecular dynamics simulation. Experimental and computational results showed significant PLA2 inhibition activity.