Characterization and antioxidant activity of Ginkgo biloba exocarp polysaccharides

Purification, structure and anti-oxidation of polysaccharides from the fruit of Nitraria tangutorum Bobr

In this paper, polysaccharides were extracted from the fruits of Nitraria tangutorum Bobr. (NTWP) using a hot water extraction method and extraction conditions were optimized by RSM. The optimal conditions were determined as follows: extraction time 7 h, extraction temperature 60 °C, ratio of water to raw material 15 : 1, and with these conditions, the yield was 14.01 ± 0.11%. After purification using DEAE-cellulose column and Sephadex G-200 column, NTWP-II was successfully obtained. The results of GC-MS and SEC-LLS analysis suggested that monosaccharide composition of NTWP-II was composed of Rha, Ara, Man, Glc and Gal with the molar ratio of 1.14 : 2.5 : 3.00 : 2.69 : 5.28 and M_w, M_w/M_n and R_z 2.29 × 10⁵, 1.32, 15.22. The detailed structure of NTWP-II was characterized by FT-IR, NMR. Based on these analyses, the structure of the repeating unit of NTWP-II was established.

Antioxidant activity of NTWP-II, evaluated in vitro, indicates that NTWP-II has good potential as a natural antioxidant used in the food industry.

The chemical structure and anti-aging bioactivity of an acid polysaccharide obtained from rose buds

An acid polysaccharide, named R-PL, was extracted from rose buds by hot water (80 °C) extraction and purified by Sephadex G-200.

Effects of dietary ginkgo biloba leaf extract on growth performance, plasma biochemical parameters, fish composition, immune responses, liver histology, and immune and apoptosis-related genes expression of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀) fed high lipid diets

For thousands of years, leaves from the Ginkgo biloba tree have been a common treatment in Chinese medicine. The present study was conducted to investigate the effects of dietary ginkgo biloba leaf extract (GBE) supplementation on growth performance, plasma biochemical parameters, fish composition, immune responses, liver histology, and immune and apoptosis-related genes expression of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀) fed high lipid diets. A basal diet supplemented with GBE at 0, 0.50, 1.00, 2.00, 4.00 and 10.00 g kg^-1 was fed to hybrid grouper for 8 weeks. The study indicated that dietary GBE did not improve growth performance and feed utilization but it reduced intraperitoneal fat rate. There were no significant differences in condition factor, viscerosomatic index, hepatosomatic index, spleen index, relative gut length, food intake, protein deposit rate and survival among all groups (P > 0.05). Dietary supplementation with 0.50-4.00 g GBE kg^-1 diets effectively increased plasma HDL content and decreased plasma GLU, LDL and TG content in fish. Furthermore, dietary GBE had a significant effect on moisture, crude protein and lipid in the liver, and protein in the whole body of fish (P < 0.05). Dietary supplementation with 0.50-1.00 g GBE kg^-1 diets effectively decreased occurrence rates of the hepatocyte swelling, hepatocyte vacuolization, and nuclei shifting to the cellular periphery cytoplasmic vacuolization, meanwhile hepatic antioxidant enzymes (SOD, CAT and T-AOC) activities significantly increased whereas MDA content significantly decreased in fish fed diets supplemented with GBE (P < 0.05). Moreover, dietary GBE up-regulated the expression of antioxidant genes (CAT, GPx and GR), immune-related genes (MHC2 and TLR3) and anti-inflammatory cytokines (IL-10 and TGF-β1), while dietary supplementation with 0.50-4.00 g GBE kg^-1 diets down-regulated apoptosis-related genes (p53, caspase-9, caspase-8 and caspase-3) expression in the head kidney of hybrid grouper. These results indicated that hybrid grouper fed diets supplemented with GBE did not improve growth performance and feed utilization but it had hypolipidemic effects, improved hepatic antioxidant status, maintained normal liver histology and preserved liver function, increased immune-related genes expression and decreased apoptosis-related genes expression in the head kidney of hybrid grouper.

Development of novel Meju starter culture using plant extracts with reduced Bacillus cereus counts and enhanced functional properties

We developed a novel type of Meju starter culture using single and combined extracts of Allium sativum (garlic clove), Nelumbo nucifera (lotus leaves), and Ginkgo biloba (ginkgo leaves) to improve the quality and functionality of Meju-based fermented products. Meju samples fermented with plant extracts (10 mg/ml) showed phenolic contents of 11.4-31.6 mg/g (gallic acid equivalents). Samples of extracts (garlic clove, lotus leaves, ginkgo leaves and their combination) fermented with Meju strongly inhibited tyrosinase, α-glucosidase, and elastase activities by 36.43-64.34%, 45.08-48.02%, and 4.52-10.90%, respectively. Specifically, ginkgo leaves extract added to fermented Meju samples at different concentrations (1% and 10%) strongly inhibited tyrosinase, α-glucosidase, and elastase activities and exhibited a potent antibacterial effect against Bacillus cereus with a significant reduction in bacterial counts compared with the effects observed for garlic clove and lotus leaf added to Meju samples. Scanning electron microscopy revealed severe morphological alterations of the B. cereus cell wall in response to ginkgo leaf extracts. Gas chromatographic mass spectroscopic analysis of plant extract-supplemented Meju samples and control Meju samples identified 113 bioactive compounds representing 98.44-99.98% total extract. The proposed approach may be useful for the development of various fermented functional foods at traditional and commercial levels.

Characterization of polysaccharides purified from Lacquer tree seed cakes and its antioxidant activity

Three polysaccharides, LTPS-1, LTPS-21 and LTPS-31 were isolated and purified from the seed cakes of lacquer tree using DEAE-52 cellulose and Sephadex G-200 column chromatography. The total sugar contents of LTPS-1, LTPS-21 and LTPS-31 were 931.8, 958.2 and 895.1 g kg^-1, respectively. LTPS-1 (3.48 kDa) was mainly composed of rhamnose, arabinose, glucose and galactose in a ratio of 35.36:5.06:1:2. LTPS-21 (11.4 kDa) was mainly composed of rhamnose, arabinose, mannose and galactose in a ratio of 41.93:21.8:1.01:9.24. LTPS-31 (19.49 kDa) was mainly composed of rhamnose, arabinose and mannose in a ratio of 38.31:16.44:1.1. IR analysis suggested they contained lower sulphuric acids, the LTPS-21 and LTPS-31 belonged to β-type polysaccharide. Among the three polysaccharides, LTPS-21 exhibited the strongest reducing power, scavenging activity on ABTS and hydroxyl radicals. These findings suggested that polysaccharides from the seed cakes could be potentially developed as natural functional ingredients in the food and cosmetic industry.

Extraction Optimization, Characterization, and Bioactivities of Polysaccharides from Pinelliae Rhizoma Praeparatum Cum Alumine Employing Ultrasound-Assisted Extraction

In this study, the ultrasound-assisted extraction of polysaccharides (PSA) from Pinelliae Rhizoma Praeparatum Cum Alumine (PRPCA) was optimized by response surface methodology (RSM). The structural characteristics of PSA were analyzed by UV-vis spectroscopy, infrared spectroscopy, scanning electron microscopy, high performance gel permeation chromatography and high performance liquid chromatography, respectively. In addition, antioxidant and antimicrobial activities of PSA were studied by different in vitro assays. Results indicated that the optimal extraction conditions were as follows: the ratio of water to raw of 30 mL/g, extraction time of 46.50 min, ultrasonic temperature of 72.00 °C, and ultrasonic power of 230 W. Under these conditions, the obtained PSA yield (13.21 ± 0.37%) was closely agreed with the predicted yield by the model. The average molecular weights of the PSA were estimated to be 5.34 × 10³ and 6.27 × 10⁵ Da. Monosaccharide composition analysis indicated that PSA consisted of mannose, galactose uronic acid, glucose, galactose, arabinose with a molar ratio of 1.83:0.55:75.75:1.94:0.45. Furthermore, PSA exhibited moderate antioxidant and antibacterial activities in vitro. Collectively, this study provides a promising strategy to obtain bioactive polysaccharides from processed products of herbal medicines.

The antibacterial activity and mechanism of ginkgolic acid C15:1

BACKGROUND

The present study investigated the antibacterial activity and underlying mechanisms of ginkgolic acid (GA) C15:1 monomer using green fluorescent protein (GFP)-labeled bacteria strains.

RESULTS

GA presented significant antibacterial activity against Gram-positive bacteria but generally did not affect the growth of Gram-negative bacteria. The studies of the antibacterial mechanism indicated that large amounts of GA (C15:1) could penetrate GFP-labeled Bacillus amyloliquefaciens in a short period of time, and as a result, led to the quenching of GFP in bacteria. In vitro results demonstrated that GA (C15:1) could inhibit the activity of multiple proteins including DNA polymerase. In vivo results showed that GA (C15:1) could significantly inhibit the biosynthesis of DNA, RNA and B. amyloliquefaciens proteins.

CONCLUSION

We speculated that GA (C15:1) achieved its antibacterial effect through inhibiting the protein activity of B. amyloliquefaciens. GA (C15:1) could not penetrate Gram-negative bacteria in large amounts, and the lipid soluble components in the bacterial cell wall could intercept GA (C15:1), which was one of the primary reasons that GA (C15:1) did not have a significant antibacterial effect on Gram-negative bacteria.

Highly fluorescent N,S-co-doped carbon dots: synthesis and multiple applications

N and S co-doped carbon dots (N,S-CDs) synthesized from biomass can be used as multicolor probes for cell imaging. The N,S-CDs can selectively and sensitively detect Cr(vi) in real lake water, human serum and living cells.

Chemical properties and antioxidant activity of a water-soluble polysaccharide from Dendrobium officinale

In this report, a water-soluble polysaccharide was obtained from the dried stems of Dendrobium officinale Kimura et Migo by hot-water (70-75°C) extraction and 85% ethanol precipitation, and successively purification by DEAE-cellulose anion-exchange chromatography and gel-permeation chromatography. The D. officinale polysaccharide (DOP) has a molecular weight of 8500Da. Monosaccharide composition analysis reveals that DOP is composed of mannose, glucose, and arabinose with a trace of galacturonic acid in a molar ratio of 6.2:2.3:2.1:0.1. Periodate oxidation-smith degradation and 1D and 2D NMR spectroscopy analysis suggest the predominance of mannose and glucose, and it contains a 2-O-acetylglucomannan and (1→4)-linked-β-d-mannopyranosyl and (1→4)-linked-β-d-glucopyranosyl residues. Atomic force microscope shows that DOP mainly exists as rod-shaped chains, supporting high degrees of polymerization. The antioxidant activities of the polysaccharide in vitro assay indicate that DOP has good scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, higher scavenging activity of hydroxyl radical, and metal chelating activities.

Functional and cell proliferative properties of an exopolysaccharide produced by Nitratireductor sp. PRIM-31

Exopolysaccharides (EPS) produced by bacteria are important source of natural biomolecules with therapeutic applications. In this study EPS produced by a strain PRIM-31 isolated from seawater from south west coast of India identified by 16S rRNA gene sequencing as Nitratireductor sp. was investigated for its biotechnological applications. The isolate produced 650 mg L(-1) EPS under optimum growth conditions. The purified EPS contained 58.3% carbohydrates with 7.08% uronic acid containing sugars, functional groups such as sulfate (2.68%) and trace amounts of proteins (0.65%). Molecular weight of the EPS was 90 kDa and monosaccharide composition was arabinose, glucose, xylose, glucuronic acid and galactose (6.6: 3.5: 2.1: 1.3: 1). The EPS displayed antioxidant activity in terms of total antioxidant capacity, ferric reducing power, scavenging of DPPH (IC50 390 μg mL(-1)) and superoxide radicals (IC50 340 μg mL(-1)). Cell proliferative activity of the EPS was evidenced by significant improvement in human dermal fibroblast (HDF) proliferation compared to control. Further, significant improvement (41%) in HDF cell migration was observed in in vitro scratch assay with EPS treatment. The EPS also showed antiproliferative activity against glioblastoma cells with an IC50 of 234.04 μg mL(-1). These functional properties of the EPS prospect its biotechnological applications.

Optimization extraction, characterization and antioxidant activities of pectic polysaccharide from tangerine peels

Response surface methodology (RSM) was employed to optimize the microwave-assisted extraction (MAE) process of pectic polysaccharide (TPPs) from tangerines peel. The optimal extraction conditions were as follows: microwave power 704 W, extraction temperature 52.2 °C, and extraction time 41.8 min Under these conditions, the experimental yield was 19.9 ± 0.2%. The purified pectic polysaccharide TPPs-2-1 was successfully obtained by anion-exchange and gel filtration chromatography. TPPs-2-1, linked mainly by α-glycosidic bonds, consisted of galacturonic acid (GalA), arabinose (Ara), galactose (Gal), rhamnose (Rha), glucose (Glc) and mannose (Man) with the average molecular weight of 17.8 kDa, and had typical IR spectra characteristic of pectic polysaccharides. Antioxidant activities were investigated on the basis of ferric-reducing antioxidant power (FRAP), hydroxyl radical (OH), 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and superoxide radical (O2(-)) scavenging assay. TPPs-2-1 exhibited significant antioxidant activity in a concentration-dependent manner and might be exploited as effective natural antioxidant applied in functional food and medicine.

Structural characterization of a polysaccharide from Chrysanthemum morifolium flowers and its antioxidant activity

The flowers of Chrysanthemum morifolium were extracted by boiling water, and a water-soluble polysaccharide (CMJA0S2) with a molecular weight of 6.5 kDa was isolated by anion-exchange chromatography on a DEAE-cellulose column and gel permeation chromatography on a Sephacryl S-300 HR column. Monosaccharide composition analysis indicated that CMJA0S2 was composed of galactose, glucose, mannose and arabinose in molar ratio of 4.1: 3.3: 1.0: 2.3. According to linkage analysis, partial acid hydrolysis and NMR spectra, the backbone was shown to contain 1, 4-linked β-Galp, 1, 4-linked β-Glcp and 1, 4-linked β-Manp, with branches substituted at C-6 of 1, 4-linked β-Manp by 1, 6-linked β-Galp and at O-6 of partial 1, 4-linked β-Galp substituted by T-linked α-Glcp. About 40% of 1, 6-linked β-Galp with T-linked α-Glcp was substituted at O-3 by α-Araf-(1→[5)-α-Araf-(1]3. The anti-oxidative analysis showed that CMJA0S2 could scavenge the DPPH radicals and relieve the damage of PC12 cells caused by H2O2, thus it could be regarded as a potential natural antioxidant.

Versatile properties of an exopolysaccharide R-PS18 produced by Rhizobium sp. PRIM-18

Exopolysaccharides (EPS) produced by bacteria have attracted scientific and industrial attention due to their multifunctional properties and relatively easier production. In this study, an EPS viz., R-PS18 produced by Rhizobium sp. PRIM-18 was characterized and its functional properties were assessed. Cell proliferative and in vitro wound healing activities of the EPS were established using human dermal fibroblast (HDF) cells. The isolate produced 2.1 g L(-1) purified EPS (molecular weight 9.33×10(6) Da) comprising of glucose, galactose, and mannose (6.1:1.8:1). Viscosity of 0.25% solution was 23.4 mPa s (shear rate 75 s(-1)) and it showed pseudoplastic and thixotropic behavior. High emulsification, iron chelation, and superoxide scavenging abilities were also observed. Significant increase in HDF cell proliferation and wound healing in vitro was achieved by R-PS18 treatment. Sulfation of R-PS18 significantly enhanced the cell proliferative and wound healing activities. In conclusion, these findings indicate potential applications of R-PS18.

Chemical characterization, antioxidant and antitumor activity of sulfated polysaccharide from Sargassum horneri

Three water-soluble polysaccharide fractions (SHP30, SHP60, and SHP80) extracted from the Sargassum horneri were obtained by water extraction and radial flow chromatography. The high-performance gel-permeation chromatography analysis showed that the average molecular weight (Mw) of three polysaccharides were approximately 1.58×10(3), 1.92×10(3) and 11.2KDa, respectively. Their in vitro antioxidant activities, antitumor activities were investigated and compared. Among these three polysaccharides, SHP30 with the highest sulfate content and intermediate molecular weight exhibited excellent antioxidant and antitumor activities in the superoxide radical assay, hydroxyl radical assay, reducing power assay, and MTT assay. Then, flow cytometry assay and quantitative real-time reverse transcription-PCR analysis suggested that the accumulation of cells in G0/G1 and S phase effecting apoptosis-associated gene expressions such as Bcl-2 and Bax might account for the growth inhibition of DLD cells by SHP30. Based on these results, we have inferred that sulfate content and molecular weight were the factors influencing antioxidant and antitumor activities.

In vitro antioxidant and antitumor activities of different sulfated polysaccharides isolated from three algae

Three sulfated polysaccharides(Ulva fasciata (UFP), Gloiopeltis furcata (GFP), Sargassum henslouianum (SHP))were isolated from three algae including green alga Ulva fasciata, red alga Gloiopeltis furcata and brown alga Sargassum henslouianum by ultrasonic extraction and radial flow chromatography. Their in vitro antioxidant and antitumor activities were investigated and compared. Among these three polysaccharides, UFP, with relatively lower sulfate content, exhibited excellent antioxidant activities in superoxide radical assay, ABTS assay and DPPH assay; however, it demonstrated the minimal inhibitory effects on growth of MKN45 gastric cancer cells and DLD intestinal cancer cells. SHP with the lowest sulfate content gained relatively lower radical scavenging rates but showed significantly higher antitumor activities. These results indicated that the in vitro antitumor and antioxidant activities of the three polysaccharides may be related to combined effects of sulfate content and uronic acid content.

Extraction, purification and antitumor activity of a water-soluble polysaccharide from the roots of Polygala tenuifolia

One polysaccharide PTP was isolated and purified from the roots of Polygala tenuifolia. It consisted of galactose, glucose and galactose in the ratio of 3.1:3.7:2.5, and a small amount of rhamnose, mannose and xylose. 17 general amino acids were identified to be components of the protein-bound polysaccharide analyzed by automatic amino acid analyzer. In order to test the anti-cancer activity of PTP, we investigated its effect against the growth of human ovarian cancer cells SKOV3 in vitro and in ovarian cancer rats. The intracellular reactive oxygen species (ROS) and glutathione (GSH) in SKOV3 cells following PTP treatment were also quantified to explore the possible mechanism underlying the antitumor activity of the polysaccharide. The result showed that PTP is effective on inhibiting the proliferation of SKOV3 cells in a concentration-dependent manner. Furthermore, treatment with PTP caused a rapid depletion of intracellular GSH content and accumulation of intracellular ROS, thus resulting in the apoptosis, which may prove to be a pivotal mechanism for its cancer protection action. In addition, a significant tumor growth inhibition effect was observed in nude mice after PTP administration for 7 weeks. All above indicated PTP could be beneficial towards ovarian cancer therapy.

Extraction of polysaccharides from herbal Scutellaria barbata D. Don (Ban-Zhi-Lian) and their antioxidant activity

The response surface methodology was employed to study the extraction of polysaccharides from Scutellaria barbata D. Don. The quantitative effects of extraction temperature, time, number and ratio of water to raw material on yield of polysaccharides were investigated with Box-Behnken design. The experimental data were fitted to a second-order polynomial equation using multiple regression analysis and also analyzed using the appropriate statistical methods. By solving the regression equation and analyzing 3D plots, the optimum condition was at extraction temperature 70 °C, time 3h, numbers 3 and ratio of water to raw material 18.5 mL/g. Under these conditions, the experimental polysaccharides yield was 2.43±0.11%, which was in good agreement with the predicted value. The antioxidant activities of the polysaccharides were evaluated in vitro. A potential antioxidant activity of S. barbata polysaccharides provides a scientific basis for the use of this herb in traditional medicine as an antioxidant.