Ethanolic Extract from Pteris wallichiana Alleviates DSS-Induced Intestinal Inflammation and Intestinal Barrier Dysfunction by Inhibiting the TLR4/NF-κB Pathway and Regulating Tight Junction Proteins.

The aim of the research was to determine the protective effect and mechanism of Pteris wallichiana J. Agardh extract (PWE) on DSS-induced ulcerative colitis (UC) in mice. In this research, PWE is rich in flavonoids and diterpenoids by UPLC-MS/MS analysis. In LPS-induced RAW264.7 cells, PWE reduced the productions of inflammatory factors (i.e., NO, TNF-α, IL-6, and IL-1ß). In DSS-induced UC in mice, PWE improved disease activity index (DAI) score, attenuated oxidative stress by decreasing MPO and MDA activities and activating GSH and SOD levels, and inhibited TNF-α, IL-6, and IL-1ß expressions in the colonic tissues. PWE also improved the intestinal barrier by upregulating the expressions of tight junction proteins, including occludin and ZO-1. Moreover, PWE extract alleviated intestinal inflammation by suppressing the TLR4/MyD88/NF-κB signaling pathway. Conclusion: PWE can alleviate DSS-induced UC in mice by increasing the expressions of intestinal tight junction proteins and inhibiting the TLR4/NF-κB inflammatory pathway.

Three novel pterosin dimers form Pteris obtusiloba.

Three novel pterosin dimmers, named as obtupterosin A (1), B (2) and C (3), together with eight known pterosins (4-11) were isolated from Pteris obtusiloba. Their structures were elucidated on the basis of ESI-MS, 1D and 2D NMR spectral data, CD, X-ray and literature comparisons. Compounds 1 and 2 were a pair of isomers. Compounds 1 and 3 were the novel type of pterosin dimer. The new compounds (1-3) were assessed for their cytotoxic activities and their α-glucosidase inhibition activity. Compounds 1-3 exhibited cytotoxic activity against HCT-116 cells with IC50 value of 27.5 µM, 30.6 µM and 12.8 µM, respectively. However, all were found to be inactive at 200 µM for α-glucosidase inhibition.

Pteris vittata coupled with phosphate rock effectively reduced As and Cd uptake by water spinach from contaminated soil.

Arsenic (As) and cadmium (Cd) are ubiquitous in the environment and they are both toxic to humans. When present in soils, they can enter food chain, thereby threatening human health. Water spinach (Ipomoea aquatica) is an important leafy vegetable, which is widely consumed in Asian countries. However, it is efficient in taking up As and Cd from soils and accumulating them in the edible parts. Therefore, it is of significance to reduce its As and Cd content, especially in contaminated soil. In this study, pot experiments were conducted to investigate the ability of As-hyperaccumulator Pteris vittata in reducing As and Cd uptake by water spinach under different phosphorus treatments. P. vittata was grown for 60 d in a contaminated-soil amended with P fertilizer (+P) or phosphate rock (+PR), followed by water spinach cultivation for another 30 d. Plant biomass, As and Cd contents in plants and soils, and soil pH were analyzed. We found that, P. vittata coupled with PR decreased the As concentration in water spinach shoots by 42%, probably due to As uptake by P. vittata. Moreover, P. vittata decreased the Cd accumulation in water spinach by 24-44%, probably due to pH increase of 0.47-0.61 after P. vittata cultivation. Taking together, the results showed that P. vittata coupled with PR decreased the As and Cd content in water spinach, which is of significance for improving food safety and protecting human health.

Efficient enrichment of total flavonoids from Pteris ensiformis Burm. extracts by macroporous adsorption resins and in vitro evaluation of antioxidant and antiproliferative activities.

The aim of this work is to develop an efficient and economical method for the enrichment of total flavonoids from Pteris ensiformis Burm. extracts. Resin screening, adsorption kinetics, adsorption isotherms and thermodynamics were successively researched prior to the dynamic adsorption and desorption tests. NKA-II resin was chosen as the best adsorbent, and the adsorption data were best described by the pseudo-second-order kinetics model and Langmuir isotherm model. The optimum enrichment conditions were as follows: for adsorption the total flavonoids concentration, flow rate and volume of sample were 1.84 mg/mL, 2 BV/h and 5 BV, respectively, and for desorption the flavonoids-loaded NKA-II resin column was desorbed by 7 BV of 50% ethanol at a rate of 2 BV/h. The product had a 6.63-fold higher total flavonoids content than crude extracts, and the recovery yield of total flavonoids was 80.65%. Furthermore, flavonoids-enriched extracts exhibited higher in vitro scavenging activity against superoxide anion radical and hydroxyl radical than crude extracts. In addition, higher antiproliferative activity of flavonoids-enriched extracts against MCF-7 and HepG-2 cell lines was also found as compared to the crude extracts. The developed method is appropriate for large-scale enrichment of total flavonoids from Pteris ensiformis Burm. extracts in the food and pharmaceutical industries.

Four New Pterosins from Pteris cretica and Their Cytotoxic Activities.

Phytochemical investigation of the aerial parts of Pteris cretica led to the isolation and elucidation of nine pterosins, including four new pterosins, creticolacton A (1), 13-hydroxy-2(R),3(R)-pterosin L (2), creticoside A (3), and spelosin 3-O-ß-d-glucopyranoside (4), together with five known pterosins 5-9. Their structures were identified mainly on the basis of 1D and 2D NMR spectral data, ESI-MS and literature comparisons. Compounds 1 and 3 were new type of petrosins with a six membered ring between C-14 and C-15. The new compounds were tested in vitro for their cytotoxic activities against four human tumor cell lines (SH-SY5Y, SGC-7901, HCT-116, Lovo). Results showed that compounds 1 and 2 exhibited cytotoxic activity against HCT-116 cells with IC50 value of 22.4 µM and 15.8 µM, respectively.

[Chemical constituents from Pteris dispar and their anti-tumor activity in vitro].

The dried whole plant of Pteris dispar were milled and extracted with 95% EtOH. The resulting dried extract was isolated by kinds of chromatographic column, including polyamide, Sephadex LH-20, preparative HPLC. As a result, ten diterpenes were isolated from the plant. By analyzing of ESI-MS and NMR spectroscopic data, the structures were established as geopyxin B(1), geopyxin E(2), ent-11α-hydroxy-18-acetoxykaur-16-ene(3), ent-14ß-hydroxy-18-acetoxykaur-16-ene(4), neolaxiflorin L(5), ent-3ß,19-dihydroxy-kaur-16-ene(6), ent-3ß-hydroxy-kaur-16-ene(7), 7ß,17-dihydroxy-16α-ent-kauran-19-oic acid 19-O-ß-D-glucopyranoside ester(8), crotonkinin C(9)and crotonkinin C(10). Compounds 1-10 were obtained from P. dispar for the first time. Compounds 1 and 2 showed moderate activities against Bel-7402 with IC50 values of 7.50 and 10.60 µmol•L⁻¹, and against HepG2 with IC50 values of 6.68,11.80 µmol•L⁻¹, respectively.

Dihydrochalcones and Diterpenoids from Pteris ensiformis and Their Bioactivities.

Two new dihydrochalcone enantiomers (+)-1 and (-)-1, along with eight known compounds 3-10, were obtained from Pteris ensiformis. The planar structures were determined on the basis of extensive 1D and 2DNMR and HRESIMS. The resolution of (+)-1 and (-)-1 was achieved by chiral HPLC analysis. The absolute configurations of (+)-1 and (-)-1 were established by the bulkiness rule using Rh2(O2CCF3)4-induced circular dichroism (ICD) method. Compounds (+)-1, (-)-1, 8, 9 and 10 exhibited the inhibitory assay of NO production in mouse macrophages stimulated by LPS, with IC50 values of 2.0, 2.5, 8.0, 9.5 and 5.6 µM, respectively. Otherwise, compound 10 showed moderate cytotoxic activity against HCT-116, HepG-2 and BGC-823 cell lines with IC50 values of 3.0, 10.5 and 6.3 µM, respectively.

Cytotoxic pterosins from Pteris multifida roots against HCT116 human colon cancer cells.

Two new pterosin glycosides, (2S,3S)-pterosin C 3-O-ß-d-(4'-(E)-caffeoyl)-glucopyranoside (1) and (2S,3S)-pterosin C 3-O-ß-d-(6'-(E)-p-coumaroyl)-glucopyranoside (2), were isolated from Pteris multifida (Pteridaceae) roots along with ten known pterosin compounds (3-12). The chemical structures of the isolated compounds were elucidated by extensive analysis of the 1D, 2D NMR, HRESIMS, and CD spectroscopic data. The cytotoxicities of 1-12 against HCT116 human colorectal cancer cell line were evaluated. Among the isolates, compound 1 showed moderate antiproliferative activity in HCT116 cells with an IC50 value of 8.0±1.7µM. Additionally, 1 induced the upregulation of the caspase-9 and procaspase-9 levels in Western blots and increased the annexin V/propidium iodide (PI)-positive cell population in flow cytometry.

Ethyl acetate fraction of Pteris vittata L. alleviates 2-acetylaminofluorene induced hepatic alterations in male Wistar rats.

Pteris vittata L. commonly called 'Brake Fern' possesses some interesting medicinal properties but its chemopreventive potential largely remains unexplored. Therefore, this study was designed to explore the chemopreventive efficacy of P. vittata L. ethyl acetate fraction (PVEA) against 2-acetylaminofluorene (2-AAF) induced liver toxicity in Wistar rats. Antioxidant activity of PVEA was evaluated using various in vitro antioxidant assays. The protective effects of PVEA were evaluated against 2-acetylaminofluorene (2-AAF) induced hepatic damage in Wistar rats. p53 expression in liver tissue was checked using immunohistochemical staining. Phytochemical composition of PVEA was determined using high performance liquid chromatography (HPLC). PVEA showed promising radical scavenging activity with an EC50 (concentration of a drug that gives half-maximal response) of 41.18µg/ml in DPPH assay, 26.99µg/ml in site specific deoxyribose degradation assay, 13.43µg/ml in non site specific deoxyribose degradation assay and 21.88µg/ml in superoxide anion scavenging assay. Three different doses of PVEA 100, 200 and 400mg/kg body weight (b.w.) followed by administration of 2-AAF (50mg/kg b.w. i.p.) for five consecutive days induced significant changes in activity of liver marker enzymes, thiobarbituric acid reactive substances, lipid hydroperoxides, reduced glutathione content and phase I and II enzymes. Activity of hepatic enzymes and normal hepatic architecture was restored following PVEA treatment. PVEA modulated the expression of p53 in liver tissue as compared to 2-AAF treated group. HPLC analysis of the fraction revealed the abundance of epicatechin (20.809ppm) and umbelliferone (22.308ppm) as major polyphenols. The present study highlights the potentiality of P. vittata in cancer chemoprevention which warrants further investigations.

Chemical characterization, anti-benign prostatic hyperplasia effect and subchronic toxicity study of total flavonoid extract of Pteris multifida.

The decoction of Pteris multifida had been applied to attenuate symptoms of benign prostatic hyperplasia in Chinese folk medicine. In this study, the total flavonoid extract of Pteris multifida was processed at first. High performance liquor chromatography and tandem mass spectrometer assay revealed 10 flavonoids as key constituents of this extract. After 60-day administration, the total flavonoid extract (180 mg/kg, i. g.) decreased the prostate index in mice of benign prostatic hyperplasia apparently. Immunohistochemical assay revealed inhibition of vascular endothelial growth factor expression, together with activation of transforming growth factor-beta 1 expression in the prostatic samples after administration of the extract. A 90-day subchronic toxicity test was further undertaken in male Sprague-Dawley rats, and the no-observed-adverse-effect level for the extract was 200 mg/kg body weight/day. These results revealed that the total flavonoid extract of Pteris multifida exhibited positive effect with safety, which might be applied in treatment of benign prostatic hyperplasia.

Pterosin Sesquiterpenoids from Pteris cretica as Hypolipidemic Agents via Activating Liver X Receptors.

Four new pterosin sesquiterpenoids (1-4), a new ent-kaurane diterpenoid (17), and 18 known compounds were isolated from the aerial parts of Pteris cretica L. The structures of the isolates were elucidated based on spectroscopic data analysis, and their absolute configurations were determined by comparison of experimental and calculated electronic circular dichroism spectra. The compounds were evaluated for lipid-lowering effects in 3T3-L1 adipocytes. Compounds 4, 8, 17, and 22 were more potent than the positive control, berberine, in decreasing triglycerides activity, with compound 4 exerting the most potent activity. Compound 4 activated LXRα/ß in a HEK 293T cell-based reporter gene assay. Molecular dynamic simulations revealed that compound 4 activates liver X receptors (LXRs) through hydrogen bonding with the residues of LXRα/ß, suggesting that compound 4 reduces total triglycerides through the regulation of LXRα/ß.

Anti-Neuroinflammatory ent-Kaurane Diterpenoids from Pteris multifida Roots.

Activated microglia are known to be a major source of cellular neuroinflammation which causes various neurodegenerative diseases, including Alzheimer's disease. In our continuing efforts to search for new bioactive phytochemicals against neuroinflammatory diseases, the 80% methanolic extract of Pteris multifida (Pteridaceae) roots was found to exhibit significant NO inhibitory activity in lipopolysaccharide (LPS)-activated BV-2 microglia cells. Three new ent-kaurane diterpenoids, pterokaurane M1 2-O-ß-d-glucopyranoside (4), 2ß,16α-dihydroxy-ent-kaurane 2,16-di-O-ß-d-glucopyranoside (10), and 2ß,16α,17-trihydroxy-ent-kaurane 2-O-ß-d-glucopyranoside (12), were isolated along with nine other known compounds from P. multifida roots. The chemical structures of the new compounds were determined by 1D- and 2D-NMR, HR-ESI-MS, and CD spectroscopic data analysis. Among the isolates, compounds 1 and 7 significantly inhibited NO production in LPS-stimulated BV-2 cells reducing the expression of the cyclooxygenase-2 (COX-2) protein and the level of pro-inflammatory mediators such as prostaglandin E2 (PGE2), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6. These results suggest that ent-kaurane diterpenes from P. multifida could be potential lead compounds that act as anti-neuroinflammatory agents.

[Chemical constituents from Pteris multifida and cytotoxic activity].

The materials were extracted by 95% ethanol, and the extracting solution was isolated by kinds of chromatographic columns including polyamide, MCI, preparative MPLC, and preparative HPLC. Eight diterpenes and two sesquiterpenes were isolated from the plant. On analysis of ESI-MS and NMR spectroscopic data, the structures were established as ent-3ß-hydroxy-kaur-16-en-19-al (1), 4-epi-kaurenic acid (2), mitrekaurenone (3), 7ß,16α,17-trihydroxy-ent-kauran-19-oic acid (4), crotonkinin E (5), crotonkinin F (6), pterisolic acid A (7), pterisolic acid C (8), (2R)-pterosin P (9), and dehydropterosin B (10). Compounds 1-6 were obtained from Pteris for the first time, and compounds 7-10 were obtained from P. ensiformis for the first time. Compounds 5-8 showed moderate activity against HCT-116, HepG2 and BGC-823 cell lines, separately.

[Influence of Uranium in Pteris vittata L. Inoculated by Arbuscular Mycorrhizal Fungus].

A pot experiment was carried out to explore the annual changes by bioremediation inoculated with 30 g Glomus versiorme in Pteris vittata L. The results showed that mycorrhizal colonization was the lowest in September 2013 (57.14%), and was the highest in March 2014 (75.20%), following the tendency firstly increasing and then decreasing. The dry biomass was markedly high in Gv than that in CK, especially in roots. The total U was significantly higher in Gv than that in CK, and was fixed predominantly into roots. The media in Gv showed less U than that in CK. It was absorbed the most to iron and manganese oxidable U and sulfide U, and each U species declined accompanying the time prolongation. In addition, bioconcentration factors were higher in Gv compared to those of CK, and both treatments were above 1. Positive relationship was found between mycorrhizal colonization and bioconcentration factors. Therefore, U uptake was enhanced inoculated by Gv, and the symbiont in arbuscular mycorrhizal fungus and Pteris vittata L. had a potential to remediate U polluted soil.

Henrin A: A New Anti-HIV Ent-Kaurane Diterpene from Pteris henryi.

Henrin A (1), a new ent-kaurane diterpene, was isolated from the leaves of Pteris henryi. The chemical structure was elucidated by analysis of the spectroscopic data including one-dimensional (1D) and two-dimensional (2D) NMR spectra, and was further confirmed by X-ray crystallographic analysis. The compound was evaluated for its biological activities against a panel of cancer cell lines, dental bacterial biofilm formation, and HIV. It displayed anti-HIV potential with an IC50 value of 9.1 µM (SI = 12.2).

[Quality standard study on Pteris multifida].

The quality control method and standard were established to control the quality of Pteris multifida in this paper. The tests of water content, total ash, acid-unsoluble ash and ethanol-soluble extractives of P. multifida were carried out according to the methods recorded in appendix of Chinese Pharmacopeia (2010 edition, volume 1) . The TLC method was established by using rhoifolin as references, and a mixture of CHCl3 -MeOH-HAc (6: 1: 1) as the developing solvent system on GF254 thin layer plate. The contents of rhoifolin was determined by HPLC on a Diamonsil C18 (4.6 mm x 250 mm, 5 µm) column, using acetonitrile-water (containing 0.15% formic acid) (16: 84) as mobile phase at a flow rate of 1.0 mL x min(-1). The column temperature was 30 degrees C and the detection wave-length was 350 nm. As a result, pterosin C 3-O-ß-D-glucosidede and the other constituents were well separated on TLC detected under the UV light at 254 nm . The methodology validation for the assay of rhoifolin presented that it was in good linear correlation in the ranges of 0.025 5-5.1 µg with the regression equations of Y = 1 092.4X + 9.503 5 (r = 0.999 8), and the average recoveries were 100.3% (RSD 1.3%). The content range of rhoifolin from 16 different batches of Pteris multifida was 0.08-5.06 mg x g(-1). The water content, total ash, acid-unsoluble ash and ethanol-soluble extractives of 16 samples varied in the ranges of 7.35% - 12.96%, 6.90% - 16.33%, 2.07% -11.38% and 13.29% -23.87%, respectively. The suggesting limes in the quality standard for water content, total ash, acid-unsoluble ash, ethanol-soluble extractives and rhoifolin content were ≤ 12% , ≤ 15% , ≤ 8.5% , ≥ 14% and ≥ 0.040%, respectively. The result proved that the established quality of control method was specific and accurate, which can be used for the quality control of P. multifida.

An unusual dihydrobenzofuroisocoumarin and ent-kaurane diterpenoids from Pteris multifida.

An unusual 5-C-methylated-dihydrobenzofuroisocoumarin, named multifidarin A (1), and two new ent-kaurane diterpenoids, named multikauranes A (2) and B (3), together with three known ent-kaurane diterpenoids, were isolated from the whole plants of Pteris multifida. The structures of 1-3 were elucidated by spectroscopic methods. The cytotoxic activities of all new compounds were evaluated against five human tumor cell lines. A possible biosynthetic process for the formation of 1 is proposed.

Suppression of SOS response in E. coli PQ 37, antioxidant potential and antiproliferative action of methanolic extract of Pteris vittata L. on human MCF-7 breast cancer cells.

Pteris vittata L. from the foothills of Kangra district, Himachal Pradesh, India has been investigated for its potential to combat reactive oxygen species and DNA damaging agents. DPPH radical, superoxide anion radical, ABTS(+.) radical cation decolorization, reducing power, deoxyribose degradation, plasmid nicking and lipid peroxidation assays were carried out to evaluate the antioxidant potential of methanolic of P. vittata L. (PME). The extract showed a significant potential in scavenging the free radicals and an IC50 of 64.425 µg/ml and 90.143 µg/ml was obtained in superoxide radical scavenging and reducing power assays respectively. PME inhibited lipid peroxidation with an IC50 of 34.35 µg/ml and protected the plasmid DNA from damage by hydroxyl radicals to varying degrees. Percentage inhibition of 81.22 and 89.36 at a concentration of 160 µg/ml was obtained in non site specific and site specific deoxyribose degradation assays respectively. PME significantly inhibited 4NQO induced mutagenicity in Escherichia coli PQ 37 and a decrease in induction factor was observed with increasing concentration. The amount of total phenolic and flavonoid content were also determined and HPLC analysis was carried out for the identification of phytoconstituents. A dose dependent decrease in viability of MCF-7 cells was observed with GI50 value of 153.967 µg/ml.

New pterosin sesquiterpenes and antitubercular constituents from Pteris ensiformis.

Two new pterosin sesquiterpenes, (2S)-13-hydroxypterosin A (1) and (2S,3S)-12-hydroxypterosin Q (2), were isolated from the whole plants of Pteris ensiformis, together with six known compounds. The structures of 1 and 2 were determined through extensive 1D/2D-NMR and MS analyses. Compound 2 exhibited antitubercular activity (MIC 6.25 µg/ml) against Mycobacterium tuberculosis H37 Rv in vitro.