Interactions between pectin, starch and linoleic acid and their effects on starch structure, digestion and release properties.

This study aimed at gaining insight into the mechanism of interactions between pectin (PE), starch and unsaturated fatty acids (UFAs) in relation to structure, in vitro digestibility and release properties of starch. Due to the barrier and encapsulation effects of PE, the complexing behavior of potato starch (PtS) with linoleic acid (LOA) was enhanced, which increased the complexing index, the compactness of network structure, short-range ordered structure and relative crystallinity of PtS-LOA-PE films. These structural changes resulted in the increases of slowly digestible starch and resistant starch and in the decreases of first-order rate coefficient in PtS-LOA-PE films. Besides, the in vitro release results also showed that the release properties of PtS-LOA could be controlled by the PE addition with the decreases in LOA release rate and increase in LOA bioavailability under simulated gastrointestinal conditions. Notably, at different PtS-LOA:PE ratios, the PtS-LOA-PE film with the PtS-LOA:PE ratio of 5:1 showed the better complexing degree, structural order, anti-digestibility and colon-targeted release properties than other PtS-LOA-PE films. These results indicated that PE influenced the release properties of the PtS-LOA-PE films, which was closely related to their complexing degree, structural order, and digestibility. This study provided new insights into the design of resistant films for delivery of UFAs to colon.

Understanding regulating effects of protein-anionic octenyl succinic anhydride-modified starch interactions on the structural, rheological, digestibility and release properties of starch.

BACKGROUND: Proteins and anionic octenyl succinic anhydride (OSA)-modified starch (OSA-starch) are common ingredients in food systems. The interactions between OSA-starch and protein are found to alter the structural and functional properties of the protein-OSA-starch complexes. In this regard, the close understanding of the relationship among the molecular interactions between whey protein isolate (WPI) and OSA-high amylose corn starch (HAS), structure changes and rheological, digestibility and release properties of WPI-OSA-HAS was investigated. RESULTS: The molecular interactions of WPI-OSA-HAS were significant for increasing the surface rough, solubility, storage modulus and loss modulus, but decreasing the R1047/1022 values. For the nutritional evaluation, the anti-digestibility of WPI-OSA-HAS was enhanced with increased resistant starch + slowly digestible starch contents and decreased equilibrium hydrolysis percentage and kinetic constant. During the digestion, part of the starch granule, OSA groups and WPI were lost, but the loss was lower than for OSA-HAS. Furthermore, the results of curcumin-loaded WPI-OSA-HAS in simulated gastrointestinal fluids demonstrated that curcumin could be gradually released to simulate colonic fluid. Notably, the interaction between WPI and OSA-HAS depended on the WPI concentration with the stronger molecular interactions obtained at 35% concentration. CONCLUSION: These results provided important information concerning how to adjust the rheological, anti-digestibility and release properties of WPI-OSA-HAS through altering the electrostatic interactions and hydrophobic interactions of WPI-OSA-HAS. © 2024 Society of Chemical Industry.

Effects of OSA-starch-fatty acid interactions on the structural, digestibility and release characteristics of high amylose corn starch.

This study investigated the effects of octenyl succinic anhydride (OSA)-starch-fatty acid (FA) interactions on the structural, digestibility and release characteristics of high amylose corn starch (HAS). FTIR and XRD analysis showed that the hydrophobic interaction between HAS and FA promoted the covalent binding between OSA and HAS. With the increasing of the FA chain length, the complex index, degree of substitution, R1047/1022 and relative crystallinity of OSA-HAS-FA increased first and then decreased, whereas the first-order rate coefficient and percentage of digested in infinite time showed an opposite trend. Structural changes and the molecular interactions of OSA-HAS-FA with 12­carbon FA resulted in highest resistant starch content (45.43%) and encapsulation efficiency of curcumin (Cur) (47.98%). In vitro release test revealed that Cur could be gradually released from OSA-HAS-FA in simulated gastric, intestinal and colonic fluids. Results provided novel insights into HAS-FA complex grafted with OSA as carrier for colon-specific of functional materials.

Characterization, in vitro digestibility and release properties of starch-linoleic acid-sodium alginate composite film.

This study aimed to improve the complexing degree, digestibility and controlled release properties of the potato starch (PS)-linoleic acid (LA) complexes by encapsulating PS-LA complexes to sodium alginate (AG) beads. The results revealed that AG had a positive effect on the complexing index, R1047/1022 values, relative crystallinity, enthalpy and morphological structure of PS-LA-AG films, especially for PS-LA-AG film with the PS-LA: AG of 5:1. The in vitro digestion and hydrolysis kinetic analysis indicated that AG addition reduced the digestibility of PS-LA-AG films to a higher slowly digestible starch content and resistant starch content and a lower equilibrium hydrolysis percentage and kinetic constant. Furthermore, in vivo release study of PS-LA-AG films indicated a restrained release in simulated gastrointestinal conditions. Consequently, the results indicated that AG addition significantly improved the inclusion efficiency for the complex formation between PS and LA, which was beneficial for the design of resistant films to entrap and control release of unsaturated fatty.

Application of Pickering emulsions stabilized by corn, potato and pea starch nanoparticles: Effect of environmental conditions and approach for curcumin release.

To apply octenyl succinic anhydride (OSA)-modified corn, potato and pea starch nanoparticles (OCSNPs, OPtSNPs and OPSNPs, respectively) as Pickering emulsion stabilizers, effect of environmental conditions such as 30 days of storage period, pH of 1-11, ionic strength of 0.1-0.9 mol/L and heat of 30-90 °C on the stability of the emulsions was evaluated. Compared with emulsions stabilized by starch nanoparticles (SNPs), the emulsions stabilized by OSA-modified SNPs (OSNPs) kept stable against different environmental stresses (pH, ionic strength and heat) as well as for a storage period of 30 days, especially for OPtSNPs. Additionally, oiling-off was not observed in OSNPs emulsions over the storage time. OSNPs emulsions also showed improved protection on curcumin during storage and controlled release during in vitro digestion. These findings enlarged the application of OCSNPs, OPtSNPs and OPSNPs stabilized-Pickering emulsion in food systems and deliver system.

Structural and in vitro starch digestion properties of starch-fatty acid nanocomplexes: effect of chain lengths and degree of unsaturation of fatty acids.

BACKGROUND: The structural and digestion properties of starch-lipid complexes are closely related to the properties of lipids. The chain length and degree of unsaturation of fatty acids (FAs), which can affect the structural and digestion properties of starch-lipid nanocomplexes, therefore need to be examined in detail to gain a better understanding of this. In this study, the effects of chain length (10-18 carbons) and degree of unsaturation (0-2) of FA on the structural and in vitro starch digestion properties of high amylose corn starch (HAS)-FA nanocomplexes were investigated, as was the correlation between their structural alterations and digestibility. RESULTS: This study showed that HAS-FA nanocomplexes with 10-carbon (38.55%) and 12-carbon (44.56%) FAs displayed high-resistant starch (RS) and slowly digestible starch (SDS) content, whereas those with 18-carbon FAs with two double bonds exhibited low RS + SDS content (23.41%). The complexing index, R1047/1022 , relative crystallinity, and enthalpy change in the HAS-FA nanocomplexes also increased with the reduction in the chain length (except for 10-carbon FA) and the degree of unsaturation of FAs, whereas the equilibrium hydrolysis percentage, kinetic constant and apparent amylose content showed an opposite trend. CONCLUSION: Chain length and degree of unsaturation of FAs affected the digestibility of HAS-FA nanocomplexes. The HAS-FA nanocomplexes with 12-carbon FAs displayed high RS + SDS content with higher degrees of molecular order at long-range and short-range levels. Results provided guidelines to regulate the digestibility of starch-fatty acid nanocomplexes by varying the FA structures. © 2022 Society of Chemical Industry.

Comparison of Intravenous and Inhalational Anesthetic on Postoperative Cognitive Outcomes in Elderly Patients Undergoing Cancer Surgery: Systematic Review and Meta-analysis.

PURPOSE: Previous studies have documented consistent findings on the long-term cognitive effects such as postoperative cognitive dysfunction (POCD), delirium and delayed recovery among elderly undergoing cancer surgery. This review was conducted to compare the effect of intravenous and inhalational anesthetic on the postoperative cognitive outcomes among elderly patients undergoing cancer surgery. DESIGN: Systematic review and meta-analysis METHODS: We searched Medline, EMBASE, PubMed Central, ScienceDirect, Google Scholar, and Cochrane library from inception until May 2021. We carried out a meta-analysis with a random-effects model and reported pooled risk ratio (RR) or standardized mean difference (SMD) with 95% confidence interval (CI) depending on the type of outcome. FINDINGS: In total, we analyzed 10 studies including 2,333 participants. Half of the studies had high risk of bias. For the cognitive score, the pooled SMD was -0.87 [95% CI: -3.97 to 2.24] indicating no statistically significant difference between inhalational and intravenous anesthetic. For POCD, the pooled RR was 1.24 (95% CI: 0.83-1.84); for postoperative delirium, the pooled RR was 2.26 (95% CI: 0.79-6.44); for delayed neurocognitive recovery, the pooled RR was 1.49 (95% CI: 1.09-2.03). CONCLUSION: Inhalational anesthetics did not show a significant difference in postoperative cognitive outcomes, except delayed neurocognitive recovery, compared to intravenous anesthetic following cancer surgery.

Zipper head mechanism of telomere synthesis by human telomerase.

Telomerase, a multi-subunit ribonucleoprotein complex, is a unique reverse transcriptase that catalyzes the processive addition of a repeat sequence to extend the telomere end using a short fragment of its own RNA component as the template. Despite recent structural characterizations of human and Tetrahymena telomerase, it is still a mystery how telomerase repeatedly uses its RNA template to synthesize telomeric DNA. Here, we report the cryo-EM structure of human telomerase holoenzyme bound with telomeric DNA at resolutions of 3.5 Å and 3.9 Å for the catalytic core and biogenesis module, respectively. The structure reveals that a leucine residue Leu980 in telomerase reverse transcriptase (TERT) catalytic subunit functions as a zipper head to limit the length of the short primer-template duplex in the active center. Moreover, our structural and computational analyses suggest that TERT and telomerase RNA (hTR) are organized to harbor a preformed active site that can accommodate short primer-template duplex substrates for catalysis. Furthermore, our findings unveil a double-fingers architecture in TERT that ensures nucleotide addition processivity of human telomerase. We propose that the zipper head Leu980 is a structural determinant for the sequence-based pausing signal of DNA synthesis that coincides with the RNA element-based physical template boundary. Functional analyses unveil that the non-glycine zipper head plays an essential role in both telomerase repeat addition processivity and telomere length homeostasis. In addition, we also demonstrate that this zipper head mechanism is conserved in all eukaryotic telomerases. Together, our study provides an integrated model for telomerase-mediated telomere synthesis.

Understanding the aggregation structure, digestive and rheological properties of corn, potato, and pea starches modified by ultrasonic frequency.

Corn starch (CS), potato starch (PtS), and pea starch (PS) were modified by ultrasonic frequency (codes as UFCS, UFPtS and UFPS), and changes in aggregation structure, digestibility and rheology were investigated. For UFCS, the apparent amylose content and gelatinization enthalpy (∆H) decreased, while the R1047/1022 values and relative crystallinity (RC) increased under lower ultrasonic frequencies (20 kHz and 25 kHz). For UFPtS, the apparent amylose content, R1047/1022 values and RC increased, while the ∆H decreased under a higher ultrasonic frequency (28 kHz). For UFPS, the apparent amylose content, R1047/1022 values, RC, ∆H decreased at 20 kHz, 25 kHz and 28 kHz. Cracks were observed on the surface of UFCS, UFPtS and UFPS. These aggregation structure changes increased the resistant starch content to 31.11% (20 kHz) and 26.45% (25 kHz) for UFCS and to 39.68% (28 kHz) for UFPtS, but decreased the resistant starch content to 18.46% (28 kHz) for UFPS. Consistency coefficient, storage modulus, and loss modulus of UFCS, UFPtS and UFPS increased, while the flow behavior index and damping factor decreased. Results indicated that CS, PtS and PS had diverse digestion and rheology behaviors after ultrasonic frequency modification, which fulfilled different demands in starch-based products.

Changes in structural, digestive, and rheological properties of corn, potato, and pea starches as influenced by different ultrasonic treatments.

Ultrasound was widely used in starch modification, whereas there was no review focusing on the effects of different ultrasonic treatments on A-, B- and C-type starches. In this study, the effects of ultrasonic power (UP, 100-600 W) and ultrasonic time (UT, 5-35 min) on structural, digestibility and rheology of corn starch (CS), potato starch (PtS), and pea starch (PS) were investigated. As a result, UP and UT decreased the apparent amylose content of CS and PS, while increased the apparent amylose content of PtS. UP and UT enhanced R1047/1022 values of CS, whereas those of PtS and PS were decreased. Moreover, UP and UT decreased the gelatinization enthalpy of CS, PtS and PS. In vitro digestion revealed that UP and UT decreased the resistant starch content of PtS and PS, but increased the resistant starch content of CS. Rheological tests indicated that UP and UT decreased the flow behavior index of CS, PtS and PS pastes, and caused an increase in storage modulus and loss modulus. Results revealed that ultrasonic treatment represented a promising technology to obtain CS, PtS and PS with tailored digestibility and rheology, which allowed the texture and glycemic response of starch-based products to be adjusted.

Preparation of autoxidative water-reducible alkyd resins from waste polyethylene terephthalate.

In this paper, the waste polyethylene terephthalate (PET) was glycolysed by trimethylolpropane with zinc acetate as catalyst. The effects of different content glycolysis product of waste PET on the appearance, viscosity, particle size and molecular weight of autoxidative water-reducible alkyd resins and the corresponding film adhesion, flexibility, impact resistance, gloss, hardness and chemical resistance were studied. Meanwhile, experimental results were compared with commercial water-reducible alkyd and water-reducible alkyd without the glycolysis product of waste PET. The results show that the maximum concentration of PET in autoxidative water-reducible alkyd resins can reach 8.5 wt%, and the molecular weight, particle size and viscosity of water-reducible alkyd resin do not change much with the increase of PET concentration. The introduction of PET resulted in the viscosity of water-reducible alkyd resins being greater than that of water-reducible alkyd resin without PET; this is mainly because PET contains harder terephthalic acid monomer units. However, the particle size of water-reducible alkyd resins with waste PET is significantly lower than that of the water-reducible alkyd resin without PET; this is due to PET-free water-reducible alkyd resin containing more pentaerythritol with greater steric hindrance. In addition, the hardness of the water-reducible alkyd resin paint film (PET content is 8.5%) reaches 1H, which is higher than the hardness (HB) of the water-reducible alkyd resin paint film without PET and the commercial alkyd resin paint film, while the physical properties and chemical resistance of the former are comparable to those of the latter two kinds of paint films. Therefore, the use of waste PET in water-borne coatings systems not only reduces the cost of coatings, but also opens up a new market for recycled PET, which may contribute a promising method for management of waste PET.

Structural changes of A-, B- and C-type starches of corn, potato and pea as influenced by sonication temperature and their relationships with digestibility.

The effect of sonication temperature on the structures and digestion behaviour of corn starch (CS, A-type), potato starch (PtS, B-type), and pea starch (PS, C-type) was investigated. For CS, sonication temperature resulted in a rough surface, decreased apparent amylose content, gelatinization enthalpy and gelatinization degree, increased short-range orders, long-range orders, retrogradation degree and resistant starch content. For PtS, sonication temperature led to a coarser surface with scratches, increased apparent amylose content and gelatinization degree, decreased short-range orders, long-range orders, gelatinization enthalpy, retrogradation degree, and resistant starch content. For PS, sonication temperature showed partial disintegration on surface, increased gelatinization degree, decreased apparent amylose content, short-range orders, long-range orders, gelatinization enthalpy, retrogradation degree and resistant starch content. This study suggested that starch digestion features could be controlled by the crystalline pattern of starch used and the extent of sonication temperature, and thus were of value for rational control of starch digestion features.

Modulating the in vitro digestibility of chemically modified starch ingredient by a non-thermal processing technology of ultrasonic treatment.

Chemically modified starch (RS4) was commercially available as a food ingredient, however, there was a lack of knowledge on how ultrasonic treatment (non-thermal technology) modulated the enzymatic resistance of RS4. In this study, structural change of RS4 during ultrasonic treatment and its resulting digestibility was investigated. Results from scanning electron microscopy, particle size analysis, chemical composition analysis, X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared spectroscopy showed that ultrasonic treatment remained the granule morphology, increased the apparent amylose content, reduced the particle size, destroyed the crystalline structure, decreased the helical orders, but enhanced the short-range molecular orders of ultrasonic-processed RS4. In vitro digestibility analysis showed that the total content of rapidly digestible starch and slowly digestible starch was increased, whereas the content of resistant starch was decreased. Overall, ultrasonic treatment substantially reduced the enzymatic resistance of RS4, indicating that RS4 was not stability against the non-thermal processing technology of ultrasonic treatment.

Upregulation of RIN3 induces endosomal dysfunction in Alzheimer's disease.

BACKGROUND: In Alzheimer's Disease (AD), about one-third of the risk genes identified by GWAS encode proteins that function predominantly in the endocytic pathways. Among them, the Ras and Rab Interactor 3(RIN3) is a guanine nucleotide exchange factor (GEF) for the Rab5 small GTPase family and has been implicated to be a risk factor for both late onset AD (LOAD) and sporadic early onset AD (sEOAD). However, how RIN3 is linked to AD pathogenesis is currently undefined. METHODS: Quantitative PCR and immunoblotting were used to measure the RIN3 expression level in mouse brain tissues and cultured basal forebrain cholinergic neuron (BFCNs). Immunostaining was used to define subcellular localization of RIN3 and to visualize endosomal changes in cultured primary BFCNs and PC12 cells. Recombinant flag-tagged RIN3 protein was purified from HEK293T cells and was used to define RIN3-interactomes by mass spectrometry. RIN3-interacting partners were validated by co-immunoprecipitation, immunofluorescence and yeast two hybrid assays. Live imaging of primary neurons was used to examine axonal transport of amyloid precursor protein (APP) and ß-secretase 1 (BACE1). Immunoblotting was used to detect protein expression, processing of APP and phosphorylated forms of Tau. RESULTS: We have shown that RIN3 mRNA level was significantly increased in the hippocampus and cortex of APP/PS1 mouse brain. Basal forebrain cholinergic neurons (BFCNs) cultured from E18 APP/PS1 mouse embryos also showed increased RIN3 expression accompanied by early endosome enlargement. In addition, via its proline rich domain, RIN3 recruited BIN1(bridging integrator 1) and CD2AP (CD2 associated protein), two other AD risk factors, to early endosomes. Interestingly, overexpression of RIN3 or CD2AP promoted APP cleavage to increase its carboxyl terminal fragments (CTFs) in PC12 cells. Upregulation of RIN3 or the neuronal isoform of BIN1 increased phosphorylated Tau level. Therefore, upregulation of RIN3 expression promoted accumulation of APP CTFs and increased phosphorylated Tau. These effects by RIN3 was rescued by the expression of a dominant negative Rab5 (Rab5S34N) construct. Our study has thus pointed to that RIN3 acts through Rab5 to impact endosomal trafficking and signaling. CONCLUSION: RIN3 is significantly upregulated and correlated with endosomal dysfunction in APP/PS1 mouse. Through interacting with BIN1 and CD2AP, increased RIN3 expression alters axonal trafficking and procession of APP. Together with our previous studies, our current work has thus provided important insights into the role of RIN3 in regulating endosomal signaling and trafficking.

Understanding the mechanism of ultrasonication regulated the digestibility properties of retrograded starch following vacuum freeze drying.

The digestibility properties and structural changes of retrograded starch (RS3) induced by ultrasonic treatment (UT) were investigated. The digestion profiles showed that UT increased the slowly digestible starch (SDS) or resistant starch (RS) of RS3 as an effective green process, corresponding to a change in hydrolysis kinetic parameters (equilibrium starch hydrolysis percentage and kinetic constant). SEM analysis showed that ultrasound led to breakage of RS3 particles followed by cracking, reorientation and crystallization. Differences in amylose content, granule size, and ζ-potential were found for native RS3 and ultrasound-treated RS3 (UT-RS3). UT decreased the relative crystallinity and gelatinization enthalpy but enhanced short-range order of RS3 based on the results of XRD, DSC, and FT-IR, respectively. Surprisingly, diffractive peaks at 13°and 20° (V-type crystalline structure) and a new exothermic peak were also observed for UT-RS3. The outcome was believed to open new pathways for regulating the digestibility properties of RS3 by UT and development of low glycemic response food.

Insights into the relations between the molecular structures and digestion properties of retrograded starch after ultrasonic treatment.

In this study, ultrasound was used to modulate the molecular structure of retrograded starch (RS3) responsible for the digestion properties, and the relationships among the ultrasonic power, molecular structure, and RS3 digestibility were revealed. Results revealed that the morphological characteristics of RS3 changed after ultrasonic treatment, and high power resulted in more compact block-shape structure. The results of particle size analysis, Fourier transform infrared spectroscopy, and X-ray diffraction showed that ultrasound decreased the long-range orders but increased the median particle size, short-range orders, and V-type polymorph of ultrasound-treated RS3. A decreased (double helix of amylopectin) and an increased (single helix of V-amylose) enthalpy change were observed by differential scanning calorimeter. Digestion profiles showed that some fractions of rapidly-digestible starch were converted into slowly-digestible starch and/or resistant starch. This study provides a potential approach to regulate the digestion of starch-rich foods with desired digestibility through ultrasonic treatment.

miR-34a Inhibitor May Effectively Protect against Sevoflurane-Induced Hippocampal Apoptosis through the Wnt/ß-Catenin Pathway by Targeting Wnt1.

PURPOSE: Research has shown that sevoflurane-induced toxicity causes neurodegeneration in the developing brain. miR-34a has been found to negatively regulate ketamine-induced hippocampal apoptosis and memory impairment. However, the role of miR-34a in sevoflurane-induced hippocampal neurodegeneration remains largely unclear. MATERIALS AND METHODS: C57/BL6 mice (7-day-old) inhaled 2.3% sevoflurane for 2 h/day over 3 consecutive days. miR-34a expression was reduced through intracerebroventricular injection with miR-34a interference lentivirus vector (LV-anti-miR-34a) into mouse hippocampus after anesthesia on the first day of exposure. Hippocampal apoptosis was detected by TUNEL assay and flow cytometry analysis. Spatial memory ability was evaluated by the Morris water maze test. The interaction between miR-34a and Wnt1 was confirmed by luciferase reporter assay, RNA immunoprecipitation, Western blot, and immunofluorescence staining. The effects of miR-34a on protein levels of B-cell lymphoma 2 (Bcl-2), bcl-2-like protein 4 (Bax), and Wnt/ß-catenin pathway-related proteins were evaluated using Western blot analysis. RESULTS: Sevoflurane upregulated hippocampal miR-34a, and miR-34a inhibitor attenuated sevoflurane-induced hippocampal apoptosis and memory impairment. miR-34a negatively regulated Wnt1 expression by targeting miR-34a in hippocampal neurons. Moreover, forced expression of Wnt1 markedly undermined miR-34a-mediated enhancement of sevoflurane-induced apoptosis of hippocampal neurons, while Wnt1 silencing greatly restored anti-miR-34a-mediated repression of sevoflurane-induced apoptosis of hippocampal neurons. Increased expression of miR-34a inhibited the Wnt/ß-catenin pathway in hippocampal neurons exposed to sevoflurane, while anti-miR-34a exerted the opposite effects. CONCLUSION: miR-34a inhibitor may effectively protect against sevoflurane-induced hippocampal apoptosis via activation of the Wnt/ß-catenin pathway by targeting Wnt1.

Development and characteristics nanoscale retrograded starch as an encapsulating agent for colon-specific drug delivery.

Retrograded starch (RS III) decreased into nanoscale particles through high-speed shearing emulsification, and the unknown effects of shear speed and shear time on their particle size were explored in this study. The in vitro digestibility, structure properties, stability, and adsorption property of these nanoparticles were also determined. The prepared RS III nanoparticles showed notches and grooves on the surface, and measured an average size of approximately 300 nm with high luminosity. Resistant starch contents decreased, while in vitro digestibility results suggested that these nanoparticles still exhibited high resistance to digestion, indicating that RS III nanoparticles were suitable for colon-specific drug delivery as an encapsulating agent. FTIR, Raman and XRD experiments indicated that these nanoparticles possessed new peaks and an amorphous structure. RS III nanoparticles were found to be most stable in increased pH or decreased NaCl concentration. Moreover, RS III nanoparticles exhibited high adsorption capacities and long in vitro release properties for 5-fluorouracil with loading capacity and encapsulation efficiency of 49.20 mg/g and 49.25%, respectively.

Andrographolide protects mouse astrocytes against hypoxia injury by promoting autophagy and S100B expression.

Andrographolide (ANDRO) has been studied for its immunomodulation, anti-inflammatory, and neuroprotection effects. Because brain hypoxia is the most common factor of secondary brain injury after traumatic brain injury, we studied the role and possible mechanism of ANDRO in this process using hypoxia-injured astrocytes. Mouse cortical astrocytes C8-D1A (astrocyte type I clone from C57/BL6 strains) were subjected to 3 and 21% of O2 for various times (0-12 h) to establish an astrocyte hypoxia injury model in vitro. After hypoxia and ANDRO administration, the changes in cell viability and apoptosis were assessed using CCK-8 and flow cytometry. Expression changes in apoptosis-related proteins, autophagy-related proteins, main factors of JNK pathway, ATG5, and S100B were determined by western blot. Hypoxia remarkably damaged C8-D1A cells evidenced by reduction of cell viability and induction of apoptosis. Hypoxia also induced autophagy and overproduction of S100B. ANDRO reduced cell apoptosis and promoted cell autophagy and S100B expression. After ANDRO administration, autophagy-related proteins, S-100B, JNK pathway proteins, and ATG5 were all upregulated, while autophagy-related proteins and s100b were downregulated when the jnk pathway was inhibited or ATG5 was knocked down. ANDRO conferred a survival advantage to hypoxia-injured astrocytes by reducing cell apoptosis and promoting autophagy and s100b expression. Furthermore, the promotion of autophagy and s100b expression by ANDRO was via activation of jnk pathway and regulation of ATG5.

Polysaccharides obtained from bamboo shoots (Chimonobambusa quadrangularis) processing by-products: New insight into ethanol precipitation and characterization.

Chimonobambusa quadrangularis polysaccharides (CPS) were extracted by ultrasonic-assisted extraction from bamboo shoots (C. quadrangularis) processing by-products. Three polysaccharide fractions, CPS70, CPS75 and CPS80, were obtained by precipitation at final ethanol concentrations of 70%, 75% and 80%, respectively. The physicochemical characterization and chemical antioxidant activities of the three polysaccharide fractions were compared on the basis of HPLC, FT-IR, XRD, TGA, and antioxidant measurements in vitro. The results suggested that ethanol concentrations used for precipitation of CPS can affect its physicochemical and associated functional properties, and antioxidant activities. Compared with CPS70 and CPS80, CPS75 had lower glucose content, higher total sugar content, and higher protein and uronic acid contents. The CPS70 and CPS80 were composed of Man, Rha, GlcA, Glc, Gal, Xyl and Ara, but none of them were found to contain GalA. In contrast, CPS75 consisted of Man, Rha, GlcA, GalA, Glc, Gal, Xyl and Ara. CPS75 had the lowest medium-high-molecular-weight value (116.53-118.18kDa) and the highest medium-low-molecular-weight value (21.30-22.68kDa). Meanwhile, CPS75 exhibited better functional properties including the repose angle, swelling capacity (SC), water retention capacity (WRC), and oil retention capacity (ORC). Moreover, CPS75 possessed higher scavenging capacities on DPPH, hydroxyl and ABTS radicals, higher oxygen radical absorbance capacity (OARC), higher metal chelating activity, and more significant reducing power. According to the results above, a final ethanol concentration of 75% could be chose to precipitate polysaccharides from bamboo shoots (C. quadrangularis) processing by-products. In summary, it is strongly recommended that the ethanol concentration employed in precipitation of natural polysaccharides could be optimized in advance.