Antibacterial activity and characteristics of silver nanoparticles biosynthesized from Carduus crispus.

In recent years' synthesis of metal nanoparticle using plants has been extensively studied and recognized as a non-toxic and efficient method applicable in biomedical field. The aim of this study is to investigate the role of different parts of medical plant Carduus crispus on synthesizing silver nanoparticles and characterize the produced nanoparticle. Our study showed that silver nanoparticles (AgNP) synthesized via whole plant extract exhibited a blue shift in absorption spectra with increased optical density, which correlates to a high yield and small size. Also, the results of zeta potential, X-ray diffraction, photon cross-correlation spectroscopy analysis showed the surface charge of - 54.29 ± 4.96 mV (AgNP-S), - 42.64 ± 3.762 mV (AgNP-F), - 46.02 ± 4.17 mV (AgNP-W), the crystallite size of 36 nm (AgNP-S), 13 nm (AgNP-F), 14 nm (AgNP-W) with face-centered cubic structure and average grain sizes of 145.1 nm, 22.5 nm and 99.6 nm. Another important characteristic, such as elemental composition and constituent capping agent has been determined by energy-dispersive X-ray spectroscopy and Fourier transform infrared. The silver nanoparticles were composed of ~ 80% Ag, ~ 15% K, and ~ 7.5% Ca (or ~ 2.8% P) elements. Moreover, the results of the FTIR measurement suggested that the distinct functional groups present in both AgNP-S and AgNP-F were found in AgNP-W. The atomic force microscopy analysis revealed that AgNP-S, AgNP-F and AgNP-W had sizes of 131 nm, 33 nm and 70 nm respectively. In addition, the biosynthesized silver nanoparticles were evaluated for their cytotoxicity and antibacterial activity. At 17 µg/ml concentration, AgNP-S, AgNP-F and AgNP-W showed very low toxicity on HepG2 cell line but also high antibacterial activity. The silver nanoparticles showed antibacterial activity on both gram-negative bacterium Escherichia coli (5.5 ± 0.2 mm to 6.5 ± 0.3 mm) and gram-positive bacterium Micrococcus luteus (7 ± 0.4 mm to 7.7 ± 0.5 mm). Our study is meaningful as a first observation indicating the possibility of using special plant organs to control the characteristics of nanoparticles.

Determination of biological activity of Carduus lanuginosus: an endemic plant in Turkey.

The genus Carduus is traditionally used in the Anatolian folk medicine for treating various diseases. Therefore, the enzyme inhibiting potential, antioxidant-antimicrobial activity, and phytochemical profile of Carduus lanuginosus extracts were investigated. The analysis of phenolic compounds was carried out by using RP-HPLC for the chemical characterization of methanol extract. The total polyphenols, total phenolic and flavonoid contents, antioxidant activity (ABTS and DPPH assay), α-amylase, and α-glucosidase inhibition activities were determined using colorimetric methods. Moreover, the antimicrobial activity was examined using the disc diffusion and microdilution methods. The ethylacetate extract was found to have the highest flavonoid and phenolic content. The water and hexane extracts showed strong enzyme inhibitory activity against the α-amylase and α-glucosidase. The methanol extract was found to contain high concentration of chlorogenic acid. The hexane and ethylacetate extracts showed to have significant MIC values on Enterococcus faecium. In conclusion, the extracts of C. lanuginosus might have a significant potential for the use as a natural pharmaceutical agent.

Bioactive potential of Indian stinging plants leaf extract against pathogenic fungi.

Background & methods We investigated the in vitro antioxidant and antifungal activity by agar disc diffusion assay of leaf extract of some stinging plants namely, Urtica dioica L., Tragia involucrate L., Carduus nutans L. and Mucuna pruriens (L.) DC., against pathogenic fungi causing infections/diseases. Results M. pruriens (Disc 4), T. involucrate (Disc 2), U. dioica (Disc 1) showed significant antifungal activity against all tested pathogens, while C. nutans (Disc 3) showed intermediate activity against only Chaetomium globosum (Cg). The leaf extract of M. Pruriens showed maximum total phenol content (~1004 µg g-1 dry wt) followed by T. involucrate, C. nutans and U. dioica. However, the ascorbate was observed highest in T. involucrate (~10.3 µg g-1 dry wt) followed by M. pruriens (~9.2 µg g-1 dry wt) but the difference was not significant (p ≤ 0.05). Likewise, M. pruriens showed maximum anthocyanin content (~0.3 µg g-1 dry wt). The activity of antioxidant enzymes revealed that M. Pruriens showed maximum ascorbate peroxidase (APX) activity, while the highest guaiacol peroxidase (GPX) and catalase (CAT) activities were observed in C. nutans and U. dioica, respectively. Conclusions M. Pruriens showed potential in vitro antioxidant and antifungal activity against studied pathogens that may be used for ethno-pharmacological uses.

Characterization of four wild edible Carduus species from the Mediterranean region via phytochemical and biomolecular analyses.

Carduus species (Compositae) are widely distributed in the Mediterranean area, and traditionally used for both food and medicinal purposes. The hydroalcoholic extracts of four wild edible Carduus species collected in Sardinia (Carduus argyroa Biv., Carduus nutans subsp. macrocephalus (Desf.) Nyman, Carduus pycnocephalus L., Carduus cephalanthus Viv.) were analyzed and characterized by HPLC-PDA-MS/MS and PCR-RFLP of the nrDNA internal transcribed spacer (ITS). Flavonoids and caffeoylquinic acid derivatives were the predominant classes of secondary metabolites characterizing the extracts. The ITS region was sequenced in parallel, and a PCR-RFLP method was applied with three selective restriction enzymes. Statistical analyses, on both chemical and biomolecular results, revealed that individuals clustered according to their taxonomic classification. The combination of the two techniques discriminates the four species within the genus, giving further information on these little-investigated plants, traditionally used in the Mediterranean area and in Sardinia.

Optimized conversion of antiproliferative lignans pinoresinol and epipinoresinol: Their simultaneous isolation and identification by centrifugal partition chromatography and high performance liquid chromatography.

High amount of the valuable lignan pinoresinol (PR) was determined in Carduus nutans fruit (7.8mg/g) for the first time. A preparative separation method using two consecutive, identical steps of centrifugal partition chromatography (CPC) was developed in order (i) to isolate PR and (ii) to subsequently isolate PR and its 7' epimer epipinoresinol (EPR) simultaneously after an optimized acid treatment which resulted in PR epimerization forming equal amounts of PR and EPR, from C. nutans fruit. As optimal conditions, a two-phase solvent system consisting of methyl tert-butyl ether:acetone:water (4:3:3, v/v/v) for CPC separation, and an acid treatment performed at 50°C for 30min for the epimerization were applied. Thus, 33.7mg and 32.8mg PR and EPR, in as high as 93.7% and 92.3% purity, were isolated from 10.0gC. nutans fruit, representing 86.4% and 84.1% efficiency, respectively. Conversion characteristic of PR and EPR in acidic medium, determined as a function of time and temperature of acid treatment provides their unambiguous identification by on-line high performance liquid chromatography (HPLC). Antiproliferative assay of isolated PR and EPR in two different types of colon cancer cell lines (HCT116 and SW480) confirmed that both epimers caused a more significant decrease of viability in HCT116 cells than in SW480 cells, suggesting their similar mechanism of antiproliferative action.

Enzymatic milk clotting activity in artichoke (Cynara scolymus) leaves and alpine thistle (Carduus defloratus) flowers. Immobilization of alpine thistle aspartic protease.

Two different milk clotting enzymes, belonging to the aspartic protease family, were extracted from both artichoke leaves and alpine thistle flowers, and the latter was covalently immobilized by using a polyacrylic support containing polar epoxy groups. Our findings showed that the alpine thistle aspartic protease was successfully immobilized at pH 7.0 on Immobeads IB-150P beads and that, under these experimental conditions, an immobilization yield of about 68% and a recovery of about 54% were obtained. Since the enzyme showed an optimal pH of 5.0, a value very similar to the one generally used for milk clotting during cheese making, and exhibited a satisfactory stability over time, the use of such immobilized vegetable rennet for the production of novel dairy products is suggested.

Roots of the invasive species Carduus nutans L. and C. acanthoides L. produce large amounts of aplotaxene, a possible allelochemical.

The invasive thistle Carduus nutans has been reported to be allelopathic, yet no allelochemicals have been identified from the species. In a search for allelochemicals from C. nutans and the closely related invasive species C. acanthoides, bioassay-guided fractionation of roots and leaves of each species were conducted. Only dichloromethane extracts of the roots of both species contained a phytotoxin (aplotaxene, (Z,Z,Z)-heptadeca-1,8,11,14-tetraene) with sufficient total activity to potentially act as an allelochemical. Aplotaxene made up 0.44 % of the weight of greenhouse-grown C. acanthoides roots (ca. 20 mM in the plant) and was not found in leaves of either species. It inhibited growth of lettuce 50 % (I 50) in soil at a concentration of ca. 0.5 mg g(-1) of dry soil (ca. 6.5 mM in soil moisture). These values gave a total activity in soil value (molar concentration in the plant divided by the molarity required for 50 % growth inhibition in soil = 3.08) similar to those of some established allelochemicals. The aplotaxene I 50 for duckweed (Lemna paucicostata) in nutrient solution was less than 0.333 mM, and the compound caused cellular leakage of cucumber cotyledon discs in darkness and light at similar concentrations. Soil in which C. acanthoides had grown contained aplotaxene at a lower concentration than necessary for biological activity in our short-term soil bioassays, but these levels might have activity over longer periods of time and might be an underestimate of concentrations in undisturbed and/or rhizosphere soil.

Two new glycosides from Carduus acanthoides.

Two new glycosides, syringic acid-4-O-ß-L-arabinopyranoside and kaempferol-3-O-α-L-rhamnopyranosyl-7-O-ß-D-glucuronopyranoside, were isolated from whole plants of Carduus acanthoides (Asteraceae), and their structures were elucidated on the basis of spectroscopic analysis.

[Chemical constituents from whole plants of Carduus acanthoides].

Fourteen compounds were isolated from wholeplants of Carduus acanthoides by various chromatographic techniques including column chromatography over HP-20 macroporous resin, MCI gel, silica gel, Sephadex LH-20 and ODS and reversed-phase HPLC. Their structures were identified as salidroside (1), 2-(3,4-dihydroxyphenyl)-ethyl-O-beta-D-glucopyranoside (2), 3,5-di-hydroxyphenethyl alcohol-3-O-beta-D-glucopyranoside (3), p-coumaric acid (4), 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl) propan-1-one (5), 3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl) propan-1-one (6), syringin (7), p-hydroxybenzaldehyde (8), salicylic acid (9), tachioside (10), vanillic acid-4-O-beta-D-glucopyranoside (11), syringic aldehyde (12), 2,6-dimethoxy-4-hydroxyphenol-1-O-beta-D-glucopyranoside (13), and 2, 6-dimethoxy-p-hydroquinone-4-0-P-D-glucopyranoside (14) on the basis of spectroscopic data analysiS. All compounds were isolated from the genus Carduus for the first time except for compounds 4 and 7.

Inhibition of key enzymes linked to obesity by preparations from Mediterranean dietary plants: effects on α-amylase and pancreatic lipase activities.

One of the most important strategy in the treatment of obesity includes the development of nutrient digestion and absorption inhibitors. Inhibition of digestive enzymes is one of the most widely studied mechanisms used to determine the potential efficacy of natural products as hypolipidemic and hypoglycaemic agents. In vitro studies here reported were performed to evaluate the inhibitory activity of five species(as hydroalcoholic extracts) of edible plants from Calabria region (Italy) on amylase and lipase by monitoring the hydrolysis of p-NPC and the hydrolysis of glycoside bonds indigestible carbohydrate foods. The formulation obtained from Clematis vitalba L. exhibited the strongest inhibitory effect on pancreatic lipase (IC50=0.99 mg/ml) and on α-amylase(IC50=31.52 µg/ml). In order to explore metabolome production HPTLC analysis of the extracts was performed, revealing the predominance of (±)-catechin, caffeic acid and chlorogenic acid in C. vital ba formulation at concentration of 23.18±3.14,13.63±0.65 and 18.88±0.76 mg/g, respectively. GC/MS analysis was used to identify fatty acids and terpene composition.

Protection of apigenin against kainate-induced excitotoxicity by anti-oxidative effects.

Apigenin (5,7,4'-trihydroxyflavone) is a principal ingredient of Cirsium japonicum. These experiments were performed to determine whether apigenin has neuroprotective effects against kainic acid (KA)-induced excitotoxicity in vitro and in vivo. Intraperitoneal (i.p.) administration of apigenin (25, 50 mg/kg) decreased the seizure scores induced by KA injection (40 mg/kg, i.p.) in mice. In addition, the convulsion onset time was significantly delayed by apigenin administration. Moreover, we found that apigenin blocked KA-induced seizure-form electroencephalogram (EEG) discharge activity in the brain cortex. In hippocampal cells, apigenin inhibited KA-induced excitotoxicity in a dose-dependent manner as measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. To study the possible mechanisms underlying the in vitro neuroprotective effects of apigenin against KA-induced cytotoxicity, we also examined the effect of apigenin on intracellular reactive oxygen species (ROS) elevations in cultured hippocampal neurons and found that apigenin treatment dose-dependently inhibited intracellular ROS elevation. The remarkable reduction of glutathione (GSH) levels induced by KA in hippocampal tissues was reversed by apigenin in a dose-dependent manner. In addition, similar results were obtained after pretreatment with free radical scavengers such as trolox and dimethylthiourea (DMTU). Finally, after confirming the protective effect of apigenin in hippocampal CA3 region, we found apigenin is an active compound in KA-induced neuroprotection. These results collectively indicate that apigenin alleviates KA-induced excitotoxicity by quenching ROS as well as inhibiting GSH depletion in hippocampal neurons.

Simultaneous determination of bioactive flavonoids in some selected Korean thistles by high-performance liquid chromatography.

In order to facilitate the quality control of some selected Korean thistles (Cirsii Herb), Cirsium japonicum var ussuriense, C. japonium var spinosissimum, C. setidens, C. pendulum, C. nipponicum, Carduus crispus, and Breea segetum, a simple, accurate and reliable high performance liguid chromatography method was developed for the simultaneous determination of the six flavonoids: luteolin 5-O-glucoside (1), luteolin 7-O-glucoside (2), hispidulin 7-O-neohesperidoside (3), luteolin (4), pectolinarin (5), and apigenin (6), which were selected as the chemical markers of the thistles. Separation was achieved on an Agilent Eclipse XDB-C18 column with a gradient solvent system of 0.1% trifluoroacetic acid aqueous-methanol at a flow-rate of 1.0 mL/min and detected at 254 nm. All six calibration curves showed good linearity (R(2) > 0.991). The method was reproducible with intra- and inter-day variations of less than 6%. The recoveries were in the range of 90.01-100.05%. This analysis method was successfully utilized to quantify the six flavonoids in the 22 batches of the thistles. The results demonstrated that this method is simple, reliable and suitable for the quality control of this medicinal herb.

Comparative antioxidant activity and HPLC profiles of some selected Korean thistles.

As yet, no comparative analyses have been conducted regarding the comparative antioxidant activities and HPLC profiles of thistles distributed in Korea. Thus, this study was performed in order to evaluate the antioxidant potentials of seven Korean thistles: Cirsium lineare, Cirsium chanroenicum, Cirsium setidens, Cirsium japonicum var. ussuriense, Cirsium nipponicum, Cirslum pendulum and Carduus crispus, via peroxynitrite and DPPH free radical assays. Among seven Korean thistles, Carduus crispus exhibited the most significant antioxidant activity in both DPPH assay and peroxynitrite. In order to characterize the compounds contained in Korean thistles, we conducted HPLC analyses on the following ten flavonoids: luteolin-5-glucoside (1), luteolin-7-glucoside (2), apigenin-7-glucoside (3), hispidulin-7-neohesperidoside (4), apigenin-7-glucuronide (5), cirsimarin (6), pectolinarin (7), luteolin (8), apigenin (9) and acacetin (10). The results of our HPLC analyses indicated the presence of pectolinarin in the whole plants of C. setidens, C. lineare, C. nipponicum, C. pendulum, the aerial and underground parts of C. japonicum var. ussuriense, and the aerial parts of C. chanroenicum. Moreover, we were able to identify hispidulin-7-neohesperidoside and luteolin-7-glucoside in the whole plants of Carduus crispus, acacetin in the aerial parts of C. chanroenicum, cirsimarin in C. lineare.

A template-based mnemonic for monoamine oxidase (MAO-N) catalyzed reactions and its application to the chemo-enzymatic deracemisation of the alkaloid (+/-)-crispine A.

A template-based mnemonic has been developed for the enzyme monoamine oxidase from Aspergillus niger and has been used to successfully identify the alkaloid (+/-)-crispine A as a target for chemo-enzymatic deracemisation yielding the biologically active (R)-enantiomer in 97% e.e.

A new flavone glycoside and other constituents from Carduus crispus.

A new flavone glycoside, chrysoeriol 7-O-(2"-O-6'''-O-acetyl-beta-D-glucopyranosyl-beta-D-glucopyranoside (1), along with fourteen known compounds 2-15 were isolated from the whole plant of Carduus crispus Linn. Their structures were established on the basis of spectroscopic methods and chemical evidences. The antitumour activity of compound 1, 4 and 5 was tested. Compound 4 exhibited significant antitumour activity against HO-8901 (human ovarian neoplasm) cells.

[Studies on the chemical constituents of Carduus crispus L].

OBJECTIVE: To study the chemical constituents of Carduus crispus. METHOD: Using chromatographic methods to isolate compounds and using chemical and spectral methods to elucidate the structures of the isolated compounds. RESULT: Eight compounds were elucidated as beta-amyrin palmitate, taraxastery acetate, luteolin-7-O-alpha-L-rhamanopyranosyl-(1-->2)-beta-D-glucopyranoside, luteolin-7-O-beta-D-glucopyranoside, triacontanic acid, beta-sitosterol, stigmasterol and stigmast-7-en-3 beta-ol. CONCLUSION: All the compounds were obtained from this plant for the first time.