Asparagus Extracts Research Articles

Roots and rhizomes of wild Asparagus: Nutritional composition, bioactivity and nanoencapsulation of the most potent extract

The nutritional composition and bioactive properties of roots and rhizomes of Asparagus stipularis were evaluated. Antioxidant activity of extracts obtained by infusion was evaluated using free radicals scavenging and reducing power methods. Porcine liver primary cell was used to check the hepatotoxicity of infusions. Results revealed that Asparagus samples are likely a source of nutrients, such as dietary fibre and essential fatty acids. HPLC-DAD-ESI/MS characterization of infusions allowed the identification and quantitation of 7 phenolic compounds, all hydroxycinnamoyl derivatives, with caffeic acid as the most abundant. Roots infusion contained the highest amounts of these compounds. It also exhibited the highest antioxidant activity in all assays, with EC50 values of 0.44 ± 0.01, 0.98 ± 0.03 and 0.64 ± 0.01 mg/mL for DPPH, ABTS and FRAP assays, respectively, with no toxicity towards PLP2 primary cell cultures (GI50 > 400 μg/mL). PLGA nanoparticles loaded with root extract were prepared using solvent-evaporation double emulsion method. Nanoparticles size was about 260 nm and a polydispersity index around 0.1, with a zeta potential of about -36 mV, as well as a good encapsulation efficiency of approximately 83%. Their morphology was analysed by SEM and spherical polymeric nanoparticles with a smooth surface were observed. FTIR and DSC were also performed, which allowed corroborating the efficacy of the encapsulation and to confirm the production of a stable and robust system to load Asparagus extracts. The developed nanoparticles are expected to be used as delivery systems for bioactive compounds of A. stipularis and they could be used as an innovative dietary supplement.

Influence of pH, buffers and role of quinolinic acid, a novel iron chelating agent, in the determination of hydroxyl radical scavenging activity of plant extracts by Electron Paramagnetic Resonance (EPR)

The Fenton reaction is used to produce hydroxyl radicals for the evaluation of the antioxidant activity of plant extracts. In this paper the parameters affecting the production of hydroxyl radicals and their spin trapping with DMPO were studied. The use of quinolinic acid (Quin) as an Fe(II) ligand was proposed for antioxidant activity determination of Green tea, orange juice and asparagus extracts. Quin, buffers and pH affect the DMPO-OH signal intensity of the EPR spectra. Quin/Fe(II) and low pH enhance the OH generation. Phosphate and Tris-HCl buffers decrease the signal intensity measured in Fe(II)-sulfate and Fe(II)-Quin systems. The extracts were analyzed with Fenton systems containing Fe(II)-sulfate and Fe(II)-Quin with and without buffer. The highest activity was shown with Fe(II)-Quin without buffer, this system being less influenced by pH and chelating agents present in the extracts. This paper will help researchers to better design spin trapping experiments for food matrices.

Study on the Effect of Asparagus Extracts on Promoting Metabolism of the Body

Abstract This study aims to analyze the effective ingredients of asparagus extracts and the changes of vitamins content in mice body after the intake of asparagus extracts, thus to conclude the effect of asparagus extracts on body metabolism during exercises. Extracts were made into different concentrations of solution and given to the mice by intragastric administration. The content of micro-elements and vitamin groups in the mice body before and after the drug administration were detected respectively and biochemical index parameter values before and after swimming were measured respectively. Results showed that, 20 min after the drug administration, the content of blood lactic acid of the mice in the swimming experiment group decreased significantly. Besides, the content of muscle glycogen decreased and correspondingly the content of hepatic glycogen increased significantly (experiment group one and two: p < 0.01; experiment group 3: p < 0.05). Thus the ethanol extract solution of asparagus can effectively improve body metabolism.

Antiradical capacity and polyphenol composition of asparagus spears varieties cultivated under different sunlight conditions.

Asparagus officinalis has a high nutritional value. Asparagus is rich in a number of bioactive compounds, mainly flavonoids (quercetin), glutathione, vitamin C, vitamin E, fructans (inulin and fructooligosaccharides) and phytosterols (b-sitosterol). These compounds may play an important role in human health. The purpose of this study was to examine the antioxidant potential and polyphenol composition of white, pale-colored and green asparagus spears of different cultivars. Investigations were conducted on different asparagus spear extracts. The study included three colors of asparagus (white, pale-colored and green) from five different cultivars subjected to the ethanol extraction procedure. Total phenolic content was also determined by the Folin-Ciocalteu method. Polyphenol (phenolic acids and flavonols) composition was estimated using the HPLC method. The antioxidant properties of extracts were examined using DPPH, ABTS and metal ion chelating assays. The highest contents of phenolic and flavonoids were observed in green asparagus from Grolim and the lowest in pale-colored asparagus from Gyjmlin. It was found that both the color of asparagus and the cultivar had a significant effect on the composition of phenolic acid and flavonols. Radical scavenging activity toward DPPH• and ABTS was highest for green asparagus cv. Grolim and Eposs. The greatest number of Fe ions was chelated by samples of green asparagus cv. Grolim and Huchel's Alpha and pale-colored asparagus cv. Huchel's Alpha. It was shown that the antioxidant activity of asparagus spears measured by antiradical and chelating activity test depends on variety and color. The highest activity was found in green asparagus and the lowest was identified in white asparagus extracts. It has also been clarified that changes in flavonol and phenolic acid composition and increases in their diversity depends on growing with sunlight and variety. Asparagus can provide a valuable source of phenolic compounds in the human diet.

Phenolic composition, antioxidant capacity, energy content and gastrointestinal stability of Croatian wild edible plants

Spectrophotometric and chromatographic analysis of phenolics in water and ethanolic extracts of wild asparagus, butcher’s broom and black bryony from Croatia was conducted. Their antioxidant capacity (ABTS, DPPH and FRAP assay) and energy content were determined. The gastrointestinal stability of detected phenolics was determined using a two-phase in vitro digestion method with human enzymes. The highest phenolics yield, radical scavenging activity and ferric reducing antioxidant potential were recorded in 40 % ethanolic extract of black bryony, with glycosylated forms of kaempferol as dominant components. Quercetin-3-O-rutinoside and isorhamnetin-3-O-rutinoside were dominant phenolics in all wild asparagus extracts, and salicylic acid was predominant in butcher’s broom 40 % ethanolic extract. Phenolic acids of the three species were not stable during gastric and duodenal phases of simulated digestion. Two main black bryony kaempferol glycosides were best preserved after digestion (50 % of each). Black bryony contains more energy than wild asparagus and butcher’s broom. Accordingly, we propose black bryony as a valuable source of antioxidant kaempferol glycosides with relevant gastrointestinal stability and higher energy content than so far more conventional vegetable wild asparagus.

A comparison between supercritical fluid and pressurized liquid extraction methods for obtaining phenolic compounds from Asparagus officinalis L

Supercritical fluid and pressurized liquid extractions are investigated for effective recovery of phenolic compounds from asparagus. By the one hand, the effect of different co-solvents on supercritical fluid extraction (SFE) is examined. Results confirm that the presence of water and ethanol is essential to obtain a phenolic enriched extract with high antioxidant activity. Operative conditions influence the extraction yield, whereas the phenolic composition of the extract does not vary significantly. By the other hand, the differences among various solvents on pressurized liquid extraction (PLE) is analysed. Once again, the mixture water–ethanol gives the best results in terms of phenolic content, which are comparable with SFE and Soxhlet ones. In total, 14 phenolic derivatives were identified, being rutin the most abundant compound in all the extracts. Phenolic acids, mainly 3-O-feruloylquinic acid, represent a relevant percentage of the phenolic content of the asparagus extracts. The methods and solvents considered influence diversely the extraction of molecules with different structure.

Antifungal activity of asparagus extracts against phytopathogenic Fusarium oxysporum

Asparagus, carnation and strawberry are major horticultural crops in southern Spain, where diseases caused by soilborne pathogens are frequent. Among them, Fusarium spp. are the fungi more frequently associated to the infection of underground plant organs. Flavonoids are phenolic compounds which possess a wide range of biological activities, including antifungal activity. In this work we evaluated the in vitro effect of an extract enriched in flavonoids obtained from triguero asparagus by-products against Fusarium oxysporum pathogenic to asparagus, carnation and strawberry, as well as its safety in asparagus plants. A significant inhibition of mycelial growth and sporulation of F. oxysporum f. sp. asparagi, F. oxysporum f. sp. dianthi and F. oxysporum pathogenic to strawberry was obtained by the addition of the asparagus extract enriched in flavonoids in three independent experiments and using the amended plate technique. Besides, in vitro tests were conducted aiming at assessing the effect of the extract in asparagus plants. Seed germination and growth of asparagus in medium amended with the asparagus extract enriched in flavonoids were similar to those in the not amended medium. Our results constitute the first report of the antifungal properties of bioactive compounds, mainly flavonoids, from asparagus by-products, and show these extracts as a promising alternative within horticultural crop protection strategies.

Development of a Rapid HPLC‐UV Method for Simultaneous Quantification of Protodioscin and Rutin in White and Green Asparagus Spears

Asparagus (Asparagus officinalis L.) spears are rich in bioactive compounds such as protodioscin, a saponin, and rutin, a flavonoid. Protodioscin and rutin are routinely quantified separately, and an approach permitting simultaneous measurement would significantly improve speed of analysis. We have optimized an extraction procedure and modified a method of high-performance liquid chromatography by coupling to an ultraviolet detector to simultaneously analyze protodioscin and rutin in asparagus extracts. An acidic ethanol solvent was more efficient than methanol, acetonitrile, or water in coextraction of protodioscin and rutin. Protodioscin and rutin were detected at 210 nm, with retention times of 12.6 min and 7.9 min, respectively. The method was validated by high linear correlations between 3.13 and 1000.0 μg/mL for protodioscin (r(2)= 0.9999), and between 0.3 and 1087.5 μg/mL for rutin (r(2)= 0.9997). The limit(s) of detection and quantification for protodioscin were 1.6 μg/mL and 3.13 μg/mL, respectively, and for rutin 0.2 μg/mL and 0.3 μg/mL, respectively. White asparagus spears and the crown of the plants were revealed to be rich sources of protodioscin and contained 2.59 to 10.4 mg/g dry weight. Green asparagus spears, particularly the upper portion, were rich in rutin and contained between 1.51 and 7.29 mg/g dry weight.

Degradation of malathion in aqueous extracts obtained from different developmental stages of asparagus (Asparagus officinalis)

AbstractWhen malathion was incubated in aqueous extracts obtained from 17 vegetables and fruits at pH 7.4 and 37 °C for 4 h, asparagus extract exhibited the highest malathion degradation. The degradation effects of the extracts ranged from 100% (asparagus) to 0.5% (papaya). The highest malathion‐degradation effects obtained from extracts of asparagus at different growing stages incubated at pH 7.4 and 37 °C for 1 h was 94.4 ± 0.45% (stem length, 5–10 cm), followed by 88.0 ± 0.31% (10–15 cm), 85.1 ± 0.94 (15–20 cm), 82.2 ± 0.52 (20–25 cm), 81.2 ± 1.4% (pre‐emergent), 67.3 ± 0.67% (>25 cm), and 42.7 ± 2.1% (fern). The protein content in an asparagus extract from different growing stages was not consistent with the degradation activity of malathion. Results of time course studies on malathion degradation in asparagus extracts from different growing stages yielded half‐life times of malathion degradation ranging from 51.7 min (fern stage) to 17.3 min (stem length, 5–10 cm). Formation of α‐ and β‐malathion mono acids from malathion was detected in an incubated sample by gas chromatography/mass spectrometry. The results support the presence of carboxylesterases in asparagus extracts. Copyright © 2006 Society of Chemical Industry

Characterization of asparagus allergens: A relevant role of lipid transfer proteins

Background: No asparagus allergen has been characterized to date. Lipid transfer proteins (LTPs) have an ubiquitous distribution in plant foods and have been identified as relevant allergens in some fruits, seeds, and pollens. Objective: We sought to identify asparagus allergens and to evaluate the potential involvement of the panallergen LTP family in asparagus allergy. Methods: Eighteen patients with asthma, anaphylaxis, and/or contact urticaria after asparagus ingestion or exposure and positive skin prick test (SPT) responses and serum-specific IgE levels to asparagus were selected. Two LTPs were isolated from crude asparagus extract by using chromatographic methods and characterized by means of N-terminal amino acid sequencing. Both isolated proteins were tested by means of immunodetection, CAP inhibition assays, and SPTs. Additional asparagus allergens were located by using immunodetection with a pool of sera from patients allergic to asparagus and with rabbit polyclonal antibodies to sunflower pollen profilin and anti–complex asparagine-linked glycans antibodies. Results: The purified LTPs showed an N-terminal amino acid sequence similar to that of Pru p 3 and a strong reaction to anti-Pru p 3 antibodies. Each isolated protein reached inhibition values of up to 60% in CAP inhibition assays against asparagus extracts and elicited positive SPT responses in 9 of 18 patients with asparagus allergy. Immunodetection assays allowed us to identify profilin and cross-reacting carbohydrate determinants as asparagus IgE-binding components. Conclusion: Asparagus LTPs are relevant allergens. In addition, profilin and glycoproteins harboring complex asparagine-linked glycans can also be involved in asparagus allergy. (J Allergy Clin Immunol 2002;110:790-6.)

Brain hydroxyl radicals during hyperbaric oxygen convulsions: [formula omitted], Nana Amiridze, M.D, Ph.D., Yuhong Dang, Ph.D. and Olen R. Brown, Ph.D. Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA

The Fenton reaction is used to produce hydroxyl radicals for the evaluation of the antioxidant activity of plant extracts. In this paper the parameters affecting the production of hydroxyl radicals and their spin trapping with DMPO were studied. The use of quinolinic acid (Quin) as an Fe(II) ligand was proposed for antioxidant activity determination of Green tea, orange juice and asparagus extracts. Quin, buffers and pH affect the DMPO-OH signal intensity of the EPR spectra. Quin/Fe(II) and low pH enhance the OH generation. Phosphate and Tris-HCl buffers decrease the signal intensity measured in Fe(II)-sulfate and Fe(II)-Quin systems. The extracts were analyzed with Fenton systems containing Fe(II)-sulfate and Fe(II)-Quin with and without buffer. The highest activity was shown with Fe(II)-Quin without buffer, this system being less influenced by pH and chelating agents present in the extracts. This paper will help researchers to better design spin trapping experiments for food matrices.

Isolation and characterization of phytotoxic compounds from asparagus (Asparagus officinalis L.) roots

Potential allelochemicals from aqueous extracts of dried asparagus (Asparagus officinalis L.) roots were isolated and characterized. Active fractions separated by HPLC included ferulic, isoferulic, malic, citric, and fumaric acids. Soxhlet extraction of the residues also produced phytotoxic caffeic acid. Although none of these compounds, when applied singly, was active enough to account for the phytotoxicity of asparagus extracts, their combined effect might be additive or synergistic. An extract from lyophilized fresh root tissues contained a fraction that was one order of magnitude more toxic than any compound obtained from the dried roots. The most active component was isolated by TLC and characterized by [(1)H]NMR as methylenedioxycinnamic acid (MDCA). This compound provided severe inhibition of curly cress (Lepidium sativum L.) root and shoot growth at concentrations of 25 ppm or above.