Effects of extraction methods on antioxidant activities of polysaccharides from camellia seed cake

Polysaccharides from Artemisia argyi leaves: Environmentally friendly ultrasound-assisted extraction and antifatigue activities

Artemisia argyi leaf polysaccharide (AALPs) were prepared through ultrasound-assisted extraction (UAE), and their antifatigue activities were evaluated. Extraction was optimized using response surface methodology (RSM), which yielded the following optimal UAE conditions: ultrasonication power of 300 W, extraction temperature of 51 °C, liquid:solid ratio of 20 mL/g, and ultrasonication time of 47 mins. The above optimal conditions resulted in the maximum extraction rate of 10.49 %. Compared with hot water extraction (HWE), UAE supported higher yields and total sugar, uronic acid, and sulfate contents of AALPs. Meanwhile, AALP prepared through UAE (AALP-U) exhibited higher stability due to its smaller particle size and higher absolute value of zeta potential than AALP prepared through HWE (AALP-H). In addition, AALP-U demonstrated stronger antioxidant activity than AALP-H. In forced swimming tests on mice, AALP-U could significantly prolong swimming time with a dose-dependent effect, increase liver and muscle glycogen levels, and improve other biochemical indices, thus showing great potential for application in functional food.

Ultrasound-assisted complex enzyme extraction, structural characterization, and biological activity of polysaccharides from Ligustrum robustum

Ligustrum robustum is one of the traditional teas in China with a long history of drinking and medicinal use. Through Response surface optimization, the yield of polysaccharides extracted by ultrasonic-assisted complex enzyme (UAE-EN) method was increased to 14.10 ± 0.56 %. Neutral homogeneous polysaccharide (LRNP) and acidic homogeneous polysaccharide (LRAP-1, LRAP-2, LRAP-3) from L. robustum were purified. The molecular weights of them were 5894, 4256, 4621 and 3915 Da. LRNP was composed of glucose (Glc), galactose (Gal), arabinose (Ara) with molar percentage of 24.97, 42.38 and 30.80. Structure analysis revealed that the backbone of LRNP consisted of 1,5-linked α-Araf, 1,4-linked β-Galp, 1,6-linked β-Galp, and 1,4-linked β-Glcp with the branches of 1,2-linked α-Araf, 1,3-linked α-Araf, 1,3-linked β-Glcp and 1,6-linked β-Galp residues, some terminal residues of α-Araf, β-Glcp and α-Galp were also included. In vitro experiments showed that the four polysaccharides possessed excellent antioxidant, antitumor and hypoglycemic activities. LRNP possessed the protective effect against oxidative stress. The studies provide a basis for further exploitation of L. robustum.

Antioxidant properties of water-soluble polysaccharides prepared by co-culture fermentation of straw and shrimp shell

Herein, we present a method for producing water-soluble polysaccharides (WSPs) by co-culture fermentation of straw and shrimp shells. The chitin-degrading strain was isolated and genotypically identified as the non-pathogen Photobacterium sp. LYM-1 in this study. Photobacterium sp. LYM-1 and Aureobasidium pullulans 2012 could coexist without antagonism. WSPs concentrations were higher in co-culture fermentations of Photobacterium sp. LYM-1 and A. pullulans 2012 (PsL/AP-WSPs) compared to monocultures (PsL-WSPs and AP-WSPs). FTIR was used to examine the polysaccharide properties of three WSP fractions. The monosaccharide compositions of three WSPs fractions were primarily composed of mannose, ribose, glucosamine, glucose, galactose, and arabinose with varying molecular weights and molar ratios according to HPLC analysis. PsL/AP-WSPs showed better scavenging effects on DPPH, ABTS, and OH free radicals, demonstrating the application potential of PsL/AP-WSPs from straw and shrimp shells. The maximum yield obtained under optimum conditions (fermentation time of 6 days, temperature of 31°C, inoculum concentration of 10% (w/v), and inoculum composition of 2:1) was 5.88 ± 0.40 mg/mL, based on the PsL/AP-WSPs production optimization by orthogonal design. The results suggest that an environmentally friendly approach for WSPs production from agro-food wastes straw and shrimp shells was developed.

Physicochemical property and antioxidant activity of polysaccharide from the seed cakes of Camellia oleifera Abel

Seed cake refers to the food by‐product of Camellia oleifera Abel, and its insufficient utilization can cause serious environment pollution and resource waste. This study aimed to investigate antioxidant activities of the polysaccharide from the seed cakes of Camellia oleifera Abel (COCP) in vitro and in vivo. The physicochemical property of COCP was also determined. COCP was characterized to be an acidic glycoprotein and mainly consisted of rhamnose (Rha), arabinose (Ara), galactose (Gal), glucose (Glc), xylose (Xyl), mannose (Man), and galacturonic acid (Gal‐UA). COCP exhibited the polysaccharide's characteristic absorption in the Fourier transform infrared (FT‐IR) spectroscopy and showed as sheet‐like structures with a smooth surface under the scanning electron microscope (SEM). COCP exerted good scavenging activities on ABTS, DPPH, and OH radicals, with IC₅₀ values of 2.94, 2.24, and 5.09 mg/ml, respectively. COCP treatment improved learning and memory abilities of D‐galactose‐induced aging mice. Significant decreases were found in the levels of alanine transaminase (ALT), aspartate aminotransferase (AST), creatinine (CRE), blood urea nitrogen (BUN), creatine kinase (CK), and lactate dehydrogenase (LDH) in serum, as aging mice were supplemented with COCP. Aging mice showed obviously higher malondialdehyde (MDA) contents and lower superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px) activities in serum, brain, liver, kidney, and heart. The phenomena were noticeably reversed when mice were treated with COCP. Results indicated that COCP exerted excellent antioxidant activities in vitro and in vivo, which support its potential application as a natural antioxidant in food and medicine industries.

Effect of phenolic extracts from Camellia oleifera seed cake on the formation of polar compounds, core aldehydes, and monoepoxy oleic acids during deep-fat frying

The frying process is an excellent way to obtain food with desirable sensory. However, some harmful substances, such as aldehydes and monoepoxy oleic acids, could also be produced. This study mainly explores the inhibition of polyphenols from the Camellia oleifera seed cake extract (CSCE) on the formation of polar compounds, core aldehydes, and monoepoxy oleic acids during deep-fat frying. The results showed that the CSCE could significantly decrease peroxide, p-anisidine, total polar, and monoepoxy oleic acids compared with other groups. In addition, the CSCE could significantly inhibit the generation of oxidized triacylglycerol polymer (TGP) and oxidized triacylglycerol (ox-TG), indicating its anti-polymerization activity. The total amount of core aldehydes and glycerol ester core aldehydes (9-oxo) in soybean oil was significantly reduced. Furthermore, CSCE had a better inhibitory effect on monoepoxy fatty acids than TBHQ. Our results might be helpful to provide a basis for the search for new natural antioxidants.

Natural Polysaccharides as Preventive and Therapeutic Horizon for Neurodegenerative Diseases

Neurodegenerative diseases are a serious and widespread global public health burden amongst aging populations. The total estimated worldwide global cost of dementia was US$818 billion in 2015 and has been projected to rise to 2 trillion US$ by 2030. While advances have been made to understand different neurodegenerative disease mechanisms, effective therapeutic strategies do not generally exist. Several drugs have been proposed in the last two decades for the treatment of different types of neurodegenerative diseases, with little therapeutic benefit, and often with severe adverse and side effects. Thus, the search for novel drugs with higher efficacy and fewer drawbacks is an ongoing challenge in the treatment of neurodegenerative disease. Several natural compounds including polysaccharides have demonstrated neuroprotective and even therapeutic effects. Natural polysaccharides are widely distributed in plants, animals, algae, bacterial and fungal species, and have received considerable attention for their wide-ranging bioactivity, including their antioxidant, anti-neuroinflammatory, anticholinesterase and anti-amyloidogenic effects. In this review, we summarize different mechanisms involved in neurodegenerative diseases and the neuroprotective effects of natural polysaccharides, highlighting their potential role in the prevention and therapy of neurodegenerative disease.

Structural, rheological properties and antioxidant activities of polysaccharides from mulberry fruits (Murus alba L.) based on different extraction techniques with superfine grinding pretreatment

The structural characteristics and biological activity of polysaccharides were influenced by different extraction methods. In this study, polysaccharides from mulberry fruits (Murus alba L., which were pre-treated with superfine grinding process) (MFP) were exacted using hot-water extraction (HWE), enzyme-assisted hot water extraction (EAHE), ultrasonic-assisted hot water extraction (UAHE), and high-speed shear homogenization-assisted hot water extraction (HSEHE). The extraction yield, structure, rheological properties and antioxidant activities of MFPs were investigated. MFP extracted using the HSEHE method have the highest extraction yields than other extraction methods. The smaller particle size of mulberry powder was found to improve the extraction yields. The MFPs were obtained by the combination between different extraction methods and superfine grinding pretreatment (through 100 mesh sieve) (MFP-HWE100, MFP-EAHE100, MFP-UAHE100, MFP-HSEHE100) showed the same levels of monosaccharide compositions and glycosyl linkages, However, these methods can produce MFP with different monosaccharide proportions, branching degree, different molecular weight, particle size and microstructure. MFP-HSEHE100 achieved the lowest molecular weight and particle size, which exhibited better thixotropy and antioxidant activities than other MFPs. This study identified that HSEHE was the most suitable extraction method for MFP.

A Review on the Biological Activity of Camellia Species

Medicinal plants have been used since antiquity to cure illnesses and injuries. In the last few decades, natural compounds extracted from plants have garnered the attention of scientists and the Camellia species are no exception. Several species and cultivars are widespread in Asia, namely in China, Japan, Vietnam and India, being also identified in western countries like Portugal. Tea and oil are the most valuable and appreciated Camellia subproducts extracted from Camellia sinensis and Camellia oleifera, respectively. The economic impact of these species has boosted the search for additional information about the Camellia genus. Many studies can be found in the literature reporting the health benefits of several Camellia species, namely C. sinensis, C. oleifera and Camellia japonica. These species have been highlighted as possessing antimicrobial (antibacterial, antifungal, antiviral) and antitumoral activity and as being a huge source of polyphenols such as the catechins. Particularly, epicatechin (EC), epigallocatechin (EGC), epicatechin-3-gallate (ECG), and specially epigallocatechin-3-gallate (EGCG), the major polyphenols of green tea. This paper presents a detailed review of Camellia species’ antioxidant properties and biological activity.

Purification, isolation, and structure characterization of water soluble and insoluble polysaccharides from Maitake fruiting body

The crude polysaccharides (GFP) were isolated from the Maitake fruiting body (Grifola frondosa) and purified by DEAE Cellulose-52 ionic-exchange chromatography and Sephadex G-25 gel filtration chromatography in that order. Five main fractions, GFP-1 to GFP-5 were obtained through the isolation and purification steps. Free sugars were isolated by G-25 gel filtration chromatography and identified glucose and (α,α)-trehalose by nuclear magnetic resonance (NMR). GC-MS and methylation analysis that linkages were mainly β-1,3 and β-1,6, β-1,4 and β-1,2 bonds in WIP. Seven main oligomer products were detected and their structures characterized by mass spectrum. Experimental results shown the similarity in structure between water soluble polysaccharides (WSP) and water insoluble polysaccharides (WIP), thus WSP can be the product of cell wall by breakdown.

Structure, antioxidant and immunomodulatory activity of a polysaccharide extracted from Sacha inchi seeds

In this study, a novel water-soluble polysaccharide (PVLP-1) was extracted and purified from Sacha inchi (Plukenetia volubilis L.) seeds and the structure, antioxidant and immunomodulatory activity of PVLP-1 were investigated. PVLP-1 (144 kDa) consisted of glucose (69.76%), mannose (14.86%), arabinose (10.53%), galactose (2.42%), ribose (1.23%), rhamnose (0.27%) and xylose (0.93%). PVLP-1 displayed characteristic polysaccharide bands in Fourier transform NMR spectra and infrared. The primary structure of PVLP-1 was a heteropolysaccharide with a backbone of (1 → 6)-linked glucose, sidechains of (1 → 4)-linked mannose, (1 → 4)-linked glucose and (1 → 3, 6)-linked mannose and a residue unit of →1)-linked arabinose as revealed the methylation analysis. PVLP-1 possessed good water-holding capacity (WHC), oil-holding capacity (OHC) and antioxidant capacities. Besides, PVLP-1 induced the proliferation of RAW264.7 cell and enhanced the expression of inflammatory cytokines IL-6, TNF-alpha(TNF-α) and IL-1 beta (IL-1β). The present study indicated that PVLP-1 possessed immune-enhancing bioactivities and could be functional food or adjuvant drug to improve biological immunity of immunodeficiency diseases and hypoimmunity.

Influence of different extraction techniques on recovery, purity, antioxidant activities, and microstructure of flaxseed gum

Four extraction techniques (that is, hot water extraction [HWE], alkaline-acidic extraction [AAE], ultrasound assisted extraction [UAE], and microwave assisted extraction [MAE]) were compared for flaxseed gum extraction and their influence on the yield, purity, structural characterization (monosaccharide composition, molecular weight distribution, and microstructure by transmission electron microscope), and antioxidant activity (in terms of scavenging ability of 2,2-diphenyl-1-picrylhydrazyl [DPPH], 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid [ABTS], and reducing power) was investigated. The HWE achieved higher yield (8.96%) than UAE (7.84%) followed by MAE (7.01%) and AAE (6.44%). Moreover, the four flaxseed gum (FSG) samples exhibited the identical monosaccharide composition, but slight difference was observed in the content, whereas the molecular weight ratios exhibited significant difference. All samples displayed concentration-dependent manner for all antioxidant assays. UAE-FSG showed significant higher scavenging ability on DPPH free radical, ABTS free radical, reducing power, and β-carotene bleaching assay followed by HWE-FSG, MAE-FSG, and AAE-FSG. Overall results showed that UAE was favorable to the purity of FSG, whereas HWE was more advantageous to improve the extraction yield and facile as it requires no special equipment. PRACTICAL APPLICATION: Extraction methods directly affect the recovery and purity of the extracted compound. Thus, this study could help in selection of appropriate extraction method for FSG. The results suggested that FSG possesses potential healthcare application in food industry because of their nutrition composition and antioxidant activities, and thus, it can be used for formulation of functional food as a natural antioxidant agent.

A comparison of a polysaccharide extracted from ginger (Zingiber officinale) stems and leaves using different methods: preparation, structure characteristics, and biological activities

This study investigates how extraction method impacts the yield, chemical composition, structure characteristics, hypoglycemic and antioxidant activity of polysaccharides from ginger (Zingiber officinale Roscoe) stems and leaves (GSLP). Four extraction methods were employed to obtain the GSLP, including hot water extraction (HWE), ultrasound-assisted extraction (UAE), alkaline solution extraction (ASE), and enzyme-assisted extraction (EAE). The data showed that ASE produced highest extraction yield compared to the other extraction methods. Scanning electron microscopy indicated that GSLP microstructures were greatly influenced by extraction method. Moreover, in vitro hypoglycemic activity and antioxidant activity experiments demonstrated that the biological capacities of ASE-GSLP were superior to GSLPs extracted by the other methods. Taken together, these results indicate that polysaccharides from ginger stems and leaves obtained by alkali, complex enzyme, and ultrasonic-assisted extractions are imbued with different characteristic mechanisms of degradation, despite the uniformity of their main structures. In addition, ASE-GSLP displayed better biological activities probably due to its abundant uronic acid content, higher sulfate radical, and smaller molecular weight. Thus, it can be concluded that ASE has great potential as an effective strategy for obtaining polysaccharides from stems and leaves because of its higher yield and the remarkable bioactivity of its products.

The Effect of Camellia oleifera Cake Polysaccharides on Growth Performance, Carcass Traits, Meat Quality, Blood Profile, and Caecum Microorganisms in Yellow Broilers

Simple Summary

Plant originated polysaccharides used as feed additives have gradually become popular for the health and nutrition of broilers. In the present study, polysaccharides from Camellia oleifera cake (CCP) were added to the daily diet of yellow broilers. Our results indicated that the immunity of the broilers was boosted due to the increasing weight or index of gizzard, spleen, and the thymus. CCP treatment improved the juiciness and changed the meat color of broilers by increasing the cooking loss and the yellowness. Additionally, the structure of intestinal flora altered as a response to the CCP supplementation, which favored the health of broilers. Results have revealed that CCP has potential and development value as a new type of feed additive for broilers.

Abstract

The study was carried out to evaluate the influence of polysaccharides from Camellia oleifera cake (CCP) in Lingnan yellow broilers diet from 1 to 50 days. Growth performance, carcass traits, meat quality, blood profile, and caecum microorganisms were characterized by three different levels of 0, 200 and 800 mg/kg CCP supplementation. Dietary treatment did not affect the productive trait from 1 to 50 days of age, except that average daily feed intake decreased at 42 days of age (p < 0.05). Additionally, the effects of CCP on various organs were different. The weight (p < 0.01) and index (p < 0.05) of bursa of Fabricius gradually decreased with the higher CCP supplementation at 21 days of the broilers diet. The gizzard weights were all higher when the broilers were fed with higher CCP concentration at 21, 42, and 50 days, respectively (p < 0.05). The weight and index of the spleen increased most with low CCP concentration (200 mg/kg) at 42 and 50 days. Moreover, CCP addition had no significant effect on meat quality except cooking loss (P < 0.05) and yellowness of meat color (p < 0.05). In the study of blood metabolism at 50 days of broilers, the concentration of calcium (p < 0.01), total cholesterol (p < 0.05) and uric acid (p < 0.01) decreased with higher CCP supplementation. CCP increased the albumin concentration (p < 0.001) that was highest at 200 mg/kg CCP supplementation. The addition of CCP increased the number of Lactobacillus and Enterococcus faecalis (p < 0.01) in the caecum of broilers, and had the potential to inhibit the growth of Escherichia coli (p = 0.11). Results showed that CCP played a role in improving intestinal flora and the immunity of yellow broilers.

Extraction Optimization and Evaluation of the Antioxidant and α-Glucosidase Inhibitory Activity of Polysaccharides from Chrysanthemum morifolium cv. Hangju

In order to evaluate the antioxidant and α-glucosidase activities of polysaccharides from Chrysanthemum morifolium cv. Hangju (CMPs), the response surface methodology was applied to optimize the parameters for extraction progress of CMPs by ultrasound, with heat reflex extraction (HRE) performed as the control. The difference in the physicochemical properties of polysaccharides obtained by the two methods were also investigated. The maximum yields (8.29 ± 0.18%) of polysaccharides extracted by ultrasonic assisted extraction (UAE) were obtained under the optimized conditions of ultrasonic power 501 W, extraction time 19 min, and ratio of liquid-to-raw material 41 mL/g. Polysaccharides extracted by UAE possessed lower protein contents (2.56%) and higher uronic acids contents (7.08%) and low molecular weight fractions than that by HRE. No significant differences were found in monosaccharide composition and Fourier transform infrared (FT-IR) spectra of polysaccharides extracted by UAE and HRE, while polysaccharides by UAE possessed stronger antioxidant and α-glucosidase inhibitory activities. Therefore, UAE was an efficient way to obtain CMPs.

Hovenia dulcis polysaccharides: Influence of multi-frequency ultrasonic extraction on structure, functional properties, and biological activities

The directional effect of single-frequency ultrasonic was the cause of the low extraction yield of polysaccharide macromolecule. Thus, a possible solution was to use multi-frequency ultrasonic technology to improve the yield of polysaccharide. Single-frequency (SF), dual-frequency (DF), and three-frequency (TF) ultrasonic extraction were applied to extract polysaccharides of Hovenia dulcis (HDPs). A maximal polysaccharide extraction yield (9.02 ± 0.29%) was gat using the dual-frequency ultrasonic with optimized DF conditions comprising 58.00 °C, 33.00 min, 28&40 kHz. The three HDPs were compared for their physicochemical, rheological, and functional properties, and their antioxidant activities. DF-HDPs contain higher uronic acid than SF-HDPs and TF-HDPs. Rheological tests indicated that the HDPs had excellent colloid properties and a promising potential to serve as a thickener, gelatinizer, and stabilizing agent in the food industry. Moreover, the DF-HDPs exhibited a notable oil holding capacity (3.92 ± 0.04 g oil/g), foaming capacity (35.26 ± 0.47%), and emulsion capacity (43.96 ± 0.67%). Compared to the SF- and TF-HDPs, the DF-HDPs had superior antioxidant activities. In conclusion, a better extraction method (dual-frequency ultrasonic extraction) was achieved.

Comparison of different extraction methods for polysaccharides from bamboo shoots (Chimonobambusa quadrangularis) processing by-products

The aim of this study was to evaluate the influences of extraction methods on the yield, chemical structure and antioxidant activity of polysaccharides from bamboo shoots (Chimonobambusa quadrangularis) processing by-products (CPS). CPSs were extracted by using five methods including hot water extraction (HWE), accelerated solvent extraction (ASE), ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE) and enzyme-assisted extraction (EAE). The experimental results showed that the uronic acid contents, monosaccharide contents, molecular weights and antioxidant activities of the five CPSs were significantly different. CPS extracted using ASE method (ASE-CPS) possessed the highest extraction yield (9.94%), the highest medium-high-molecular-weight value (136.07 kDa) and notable antioxidant ability. UAE-CPS had the highest uronic acid (9.42%) and the lowest medium-high-molecular weight value (117.49 kDa), and its antioxidant activity was the best. Based on the correlation analysis, the higher uronic acid content, smaller molecular weight, and lower content of monosaccharide composition of glucose for the CPS-UAE might contribute to its higher antioxidant activity. From an industrial viewpoint, ASE technique could be a promising and alternative way to extract CPS due to its high yield, notable antioxidant activity, and convenient industrialization.

Physicochemical properties and activities of comfrey polysaccharides extracted by different techniques

The effects of extraction techniques on the physicochemical properties, antioxidant activity and antihyperglycemic activity of comfrey polysaccharides (CPs) were evaluated. Four techniques were used to extract CPs: hot water extraction (HW), ultrasonic-assisted extraction (UA), enzyme-assisted extraction (EA) and enzyme-ultrasonic-assisted extraction (EUA). Experimental results indicated that CPs extracted by the UA (UA-CPs) and EUA methods (EUA-CPs) had higher extraction yields. The four CPs showed the same monosaccharide composition but a significant difference in monosaccharide content. CPs showed antioxidant activities and antihyperglycemic activities in a concentration-dependent manner. UA-CPs exhibited better antioxidant capacity, which might have been related to its smaller molecular weight and higher uronic acid content. In addition, UA-CPs showed notable α-glucosidase inhibition activity. These results suggested that ultrasonic-assisted extraction technology was more beneficial to enhance the extraction yields of the polysaccharides, and obtain higher bioactive polysaccharides from comfrey.

Characteristics and bioactivities of different molecular weight polysaccharides from camellia seed cake

Four polysaccharides, namely COP-1, COP-2, COP-3 and COP-4, were ultrafiltrated from crud Camellia oleifera seed cake polysaccharides (COP-c), purified, and characterized, including the determination of antioxidant and antiproliferative activities. Their molecular weights were 7.9, 36, 83 and 225kDa, respectively. All COPs showed the similar FT-IR spectrums, but significant differentials in monosaccharide components. COP-2 exhibited the highest radical scavenging abilities. COP-1 has the strongest metal chelating capabilities. Although with higher molecular weight, COP-4 showed the poorest antioxidant abilities. These results suggested appreciate molecular weight COP possessed a better antioxidant activities. Additionally, all COPs had non-significant antiproliferative abilities in HaLa and HepG2 cells.

The antioxidant activities effect of neutral and acidic polysaccharides from Epimedium acuminatum Franch. on Caenorhabditis elegans

A neutral polysaccharide (EAP-1N) and an acidic polysaccharide (EAP-2A) were purified from Epimedium acuminatum by DEAE-52 cellulose anion-exchange chromatography and gel-filtration chromatography. Their structures were characterized by chemical composition analysis, high-performance size exclusion chromatography (HPSEC), Fourier transform infrared spectrometry (FT-IR), and gas chromatography-mass spectrometry (GC-MS). Further, their antioxidant activities were investigated both in vitro and in vivo. Results showed that EAP-2A had higher uronic acid content and larger average molecular weight than EAP-1N. Compared with EAP-1N, EAP-2A exhibited significantly scavenging activities against free radical in vitro, as well as strongly stimulating effect on antioxidant enzyme activities (including superoxide dismutases (SOD), catalases (CAT), and glutathione peroxidases (GSH-PX)) and preferably inhibitory effect on lipid peroxidation and protein carboxyl in the mode of Caenorhabditis elegans.

Characterization of polysaccharide fractions in mulberry fruit and assessment of their antioxidant and hypoglycemic activities in vitro

Mulberry fruit polysaccharide fractions with different structural characteristics showed different antioxidant and hypoglycemic activities.

Reviews on Mechanisms of In Vitro Antioxidant Activity of Polysaccharides

It is widely acknowledged that the excessive reactive oxygen species (ROS) or reactive nitrogen species (RNS) induced oxidative stress will cause significant damage to cell structure and biomolecular function, directly or indirectly leading to a number of diseases. The overproduction of ROS/RNS will be balanced by nonenzymatic antioxidants and antioxidant enzymes. Polysaccharide or glycoconjugates derived from natural products are of considerable interest from the viewpoint of potent in vivo and in vitro antioxidant activities recently. Particularly, with regard to the in vitro antioxidant systems, polysaccharides are considered as effective free radical scavenger, reducing agent, and ferrous chelator in most of the reports. However, the underlying mechanisms of these antioxidant actions have not been illustrated systematically and sometimes controversial results appeared among various literatures. To address this issue, we summarized the latest discoveries and advancements in the study of antioxidative polysaccharides and gave a detailed description of the possible mechanisms.