Postoperative cognitive dysfunction (POCD) is a common complication induced by anesthesia or surgery, which affects the concentration, cognition and memory of patients. Sevoflurane, a clinical ...anesthetic, could stimulate neuro-inflammation and lead to POCD. Recent studies found that specificity protein 1 (SP1) participates in the development of neurological diseases. Our study aims to elucidate the role of SP1 in sevoflurane-induced POCD pathogenesis. We anesthetized Sprague–Dawley rats and treated the primary hippocampal neurons with sevoflurane to construct the in vivo and in vitro POCD models. Besides, the expression and regulatory mechanism of SP1 in the pathogenesis of POCD were explored. According to the results, sevoflurane anesthesia impaired the cognitive functions of rat, significantly elevated SP1 expression and inactivated the cholinergic anti-inflammatory pathway (CAP) both in vivo and in vitro. Moreover, the sevoflurane-treated rats and neurons also exhibited obvious inflammatory responses and enhanced apoptosis. Loss-of-function assay indicated that SP1 knockdown rescued the deactivation of CAP and alleviated the sevoflurane-induced neuro-inflammation and apoptosis in rat hippocampus. Generally, our study documented that the sevoflurane-induced SP1 up-regulation affected the activation of CAP, leading to the aggravated neuro-inflammation and apoptosis. This may provide a novel sight for POCD therapy.
•Four polysaccharides were extracted from Flammulina velutipes.•Four extraction methods were optimized by orthogonal test.•Preliminary structural characterizations were conducted of the four ...polysaccharides.•Antioxidant activities of the four polysaccharides were investigated.
Four polysaccharides (CFP, UFP, MFP and EFP) were extracted from Flammulina velutipes using hot water, ultrasonic, microwave or enzymatic methods optimized by orthogonal test. Preliminary structural characterizations were conducted using physicochemical properties. Polysaccharides extracted by all four methods showed similar physicochemical characteristics and FT-IR spectra. However, SEM images of tissues of F. velutipes were significantly different. EFP demonstrated better antioxidant activities against hydroxyl radical as well as improved metal chelating activity. UFP showed higher DPPH scavenging activity, but CFP exhibited higher antioxidant activity in reducing power. Hence, these polysaccharides can be used as natural antioxidants in functional foods or medicine. Further experiments on the biological activities of these four polysaccharides are currently in progress.
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•Three depolymerised polysaccharides were prepared through different methods.•The depolymerized SLPs exhibited higher antioxidant activity than the original SLP.•HV-SLP possessed the ...highest antioxidant activity of the three depolymerised fractions.•H2O2/Vc treatment is an effective method for preparing depolymerised SLP products.
Polysaccharides (SLP) derived from Sparassis latifolia were depolymerised by ultrasonication, hydrochloric acid, and H2O2/Vc to obtain the depolymerised polysaccharides U-SLP, H-SLP, and HV-SLP, respectively. Results from X-ray powder diffraction, atomic force microscopy, Fourier-transfrom infrared spectroscopy, proton nuclear magnetic resonance spectroscopy and scanning electron microscopy indicated that the SLP were damaged to varying degrees by the three methods. The results showed that the three depolymerisation methods broke down the molecular chains, impeded aggregation, and reduced the molecular weight of the polysaccharides without changing their primary structure and monosaccharide composition of SLP. Relative to the original SLP, the depolymerised SLPs showed higher antioxidant activity during in vitro ABTS and reducing power assays. Also, the depolymerised SLPs could effectively improve the survival rate of zebrafish and reduce their heart rate, reactive oxygen species production, and cell death. The HV-SLP had the highest antioxidant activity of the three depolymerised fractions. The results revealed that the H2O2/Vc treatment is an effective method for preparing depolymerised SLP products with low molecular weights and dramatic antioxidant activity.
► Chemical and physical characteristics of the polysaccharides were investigated. ► Antioxidant and hepatoprotective effects of the polysaccharides were investigated. ► The HEP80 showed strong ...activity on antioxidant and hepatoprotective activities. ► The hepatoprotective effect may be due to its potent antioxidant capacity.
Three fractions of the endo-polysaccharides from the mycelium of Hericium erinaceus (HEP) grown on tofu whey were obtained by the fractional precipitation with gradient concentrations of ethanol (HEP40, HEP60 and HEP80). The chemical and physical characteristics of the three crude polysaccharides were investigated by the combination of chemical and instrumental analysis methods. The studies to evaluate the antioxidant potential and the hepatoprotective effects of the three polysaccharides showed that they had different activities in different evaluation system. HEP80 showed strong activity on antioxidant in vitro and potent hepatoprotective effect in vivo and the hepatoprotective effect may be due to its potent antioxidant capacity. The HEP could be exploited as antioxidant product and a supplement in the prevention of hepatic diseases. The study also opens an avenue for the efficient utilization of tofu whey, which is usually discarded in environment, causing concerns.
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•PFSV-2 was a purified polysaccharide from Sanghuangporus vaninii.•The phytochemical properties of PFSV-2 were characterized.•PFSV-2 could reduce H2O2-induced cytotoxicity in L929 ...cells.•PFSV-2 exhibited effective protection against H2O2-stimulated oxidative stress in zebrafish.
PFSV-2 is a purified polysaccharide with good hypolipidemic activity from artificially cultivated Sanghuangporus vaninii. In this study, PFSV-2 was characterized by scanning electron microscopy, atomic force microscopy, X-ray diffraction, zeta potential, thermogravimetric analysis and the Congo red test. To assess the protective effect of PFSV-2, H2O2-induced oxidant injury on L929 cells and larval zebrafish models was employed. PFSV-2 significantly reduced H2O2-induced cytotoxicity in L929 cells by decreasing intracellular ROS levels and cell apoptosis. Furthermore, PFSV-2 had an obvious protective effect against H2O2-stimulated oxidative stress in larval zebrafish by decreasing heart rate and reducing ROS generation and cells death. Additionally, PFSV-2 decreased the production of MDA and increased the activity of antioxidant enzymes SOD and CAT in both L929 cells and larval zebrafish. These results suggested that PFSV-2 may be useful as an antioxidant in the medical and cosmetic industries.
A novel polysaccharide PSRa-2 was purified from
Stropharia rugosoannulata
fruiting bodies using high pressure homogenization-assisted dual enzyme method, ion exchange, and gel chromatography. The ...PSRa-2 was characterized via FT-IR, HPAEC, SEM, Congo red test, SEC–MALLS-RI, methylation analysis, and NMR analysis. Structural characterization revealed that PSRa-2 was an α-glucan with a Mw 455.6 kDa. The backbone of PSRa-2 was composed of →4)-α-
d
-Glc
p
-(1→ and →3)-α-
d
-Glc
p
-(1→ and branches of α-
d
-Glc
p
-(1→ at position O-6 of →4,6)-α-
d
-Glc
p
-(1→. PSRa-2 induced splenocyte proliferation and protected splenocytes against 5-Fu-induced immunosuppression by restoring the proliferation and secretion of cytokines (TNF-α and IL-2) secretion levels. Thus, PSRa-2 exhibits obviously immunomodulatory activity and represents a potential natural immunomodulator.
Graphical Abstract
Oudemansiella radicata
is a precious mushroom widely cultivated in China with mature cultivation techniques. The extraction efficiency and biological activity of polysaccharides are crucial for the ...utilization of
O. radicata
. In this study, the effects of dehydration (hot air drying and freeze-drying) and extraction methods (heat-reflux extraction, ultrasound-assisted extraction and maceration extraction) on the physicochemical properties and antioxidant activities of
Oudermansiella radicata
polysaccharides (ORPs) were investigated. Six polysaccharides were obtained, and experimental results indicated that physicochemical and antioxidant properties of ORPs were different from each other after the treatment of various dehydration and extraction techniques. Based on correlation analysis, the antioxidant activities of the ORPs could be attributed to the uronic acid content, molecular weight, and glucose and mannose contents. The freeze-drying and ultrasound-assisted methods are promising and alternative techniques for obtaining ORPs considering their high yield and notable antioxidant activity.
Graphic abstract
Abctract
The phenolic compounds from
Oudemansiella radicata
were extracted by an ultrasound-assisted extraction method (UAE) using response surface methodology. The extraction with an extraction time ...35.5 min, ultrasonic power 88 W and an ethanol concentration of 45.2% was considered to be the optimal UAE conditions with the maximum total phenolic content. The
O. radicata
extracts (ORE) exhibited distinct antioxidant activities against DPPH radical, ABTS radical and hydroxyl radical, as well as DNA damage. Using UPLC-Triple-TOF–MS, eight phenolic compounds were identified. These data suggest that ORE may be utilized as a natural oxidant and this work provide a basis for the utilization of
O. radicata.
Graphic abstract
In this study, an efficient complex enzyme-assisted extraction technology was developed and optimized to extract polysaccharides from Hericium erinaceus mycelia (HEP) using the Box-Behnken design ...based on the results of single factor experiments. As a result, the optimal protocol was as follows: an extraction time of 79 min, an extraction temperature of 50°C, a pH of 5.7 and a ratio of water to raw materials of 33.4 mL/g. These optimal extraction conditions achieved the highest yield (13.9 ± 0.3%) of HEP. The purified fraction (HEP-2) was composed of glucose, galactose, mannose, fucose, arabinose, xylose and rhammnose. HEP-2 manifested an obvious inhibitory effect on the growth of HeLa cells. The overall findings implied that enzyme-assisted procedure is a superior method and that HEP-2 might be useful for developing natural and safe antitumor drugs.
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