Correlationship between self-assembly behavior and emulsion stabilization of pea protein-high methoxyl pectin complexes treated with ultrasound at pH 2.0.

This study investigated the effects of ultrasound on the self-assembly behavior of pea protein (PP)-high methoxyl pectin (HMP) complexes at pH 2.0 through transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and intrinsic fluorescence analysis. The emulsion stabilization mechanism of PP-HMP treated with ultrasound (PP-HMP-US) was also elucidated. The results indicated that ultrasound increased the emulsifying activity index (EAI) and emulsifying stability index (ESI) of PP-HMP. Moreover, PP-HMP-US-based emulsions formed small, dispersed oil drops, which were stable during storage. PP-HMP- and PP-HMP-US-based emulsions did not demonstrate any creaming. The TEM results revealed that ultrasound can regulate the self-assembly behavior of PP and HMP to form spherical particles with a core-shell structure. This structure possessed low turbidity, a small particle size, and high absolute zeta potential values. The FTIR and intrinsic fluorescence spectra demonstrated that ultrasound increased the α-helix and ß-sheet contents and exposed the tryptophan groups to more hydrophilic environments. Ultrasound also promoted the PP-HMP self-assembly through electrostatic interaction and improved its oil-water interfacial behavior, as indicated by the EAI and ESI values of PP-HMP-US-based emulsions. The current results provide a reference for the development of an innovative emulsifier prepared by ultrasound-treated protein-pectin complexes at low pH.

Interaction mechanisms of peanut protein isolate and high methoxyl pectin with ultrasound treatment: The effect of ultrasound parameters, biopolymer ratio, and pH.

Ultrasound could effectively change molecular structure of proteins, polysaccharides, and their interactions, and was used to treat the peanut protein isolate-high methoxy pectin (PPI-HMP) complexes in this study. Effects of different ultrasound parameters, PPI-HMP mixing ratio (40:1-5:2), and pH (2.0-8.0) on the PPI-HMP interactions were investigated. Turbidity, solution appearance, and Zeta-potential analysis revealed an electrostatic interaction between PPI and HMP from pH 2.0 to pH 6.0. Ultrasound changed the tertiary structure conformation of PPI according to the surface hydrophobicity analysis. Increased ultrasound power density and pH broke the hydrogen bonds between the complexes according to Fourier transform infrared spectroscopy analysis. Apparent viscosity and confocal laser scanning microscopy analysis showed that appropriate ultrasound treatment (5.43 W/cm3, 25 min, 25 °C) reduced the viscosity of the complexes, and enhanced the electrostatic and hydrophobic interactions between PPI and HMP. These findings will contribute to the application of PPI-HMP complexes in the food industry.

The droplet breakup model and characteristics of pH-shifted peanut protein isolate-high methoxyl pectin stabilised emulsions under ultrasound.

The effect of pH on the occurrence states of peanut protein isolate (PPI) and high methoxyl pectin (HMP), and droplet breakup model of the emulsions under ultrasound were studied. Particle size distribution and scanning electron microscopy results showed that PPI-HMP existed a soluble complex at pH 5.0, had no interaction at pH 7.0, and was co-soluble at pH 9.0. Droplet breakup model results revealed that the characteristics of emulsion stabilised by PPI-HMP treated at pH 5.0 was different from that at pH 7.0 and 9.0. The average diameter of the droplet well satisfied the model. According to rheological properties, interface tension, and microstructure, the formation mechanism and characteristics of emulsion stabilised by PPI-HMP treated at pH 5.0 was different from that at pH 7.0 and pH 9.0. The research provided a reference for constructing emulsions using pH-shifted PPI-HMP under ultrasound.

Lasso-Logistic regression model for the identification of serum biomarkers of neurotoxicity induced by strychnos alkaloids.

As a traditional Chinese medicine, strychnos alkaloids have wide effects including antitumor, analgesic, and anti-inflammatory. However, the therapeutic window of strychnos alkaloids is quite narrow due to potential neurotoxicity. Therefore, it is necessary to explore some efficient biomarkers to identify and predict the neurotoxicity induced by strychnos alkaloids and find a therapy to prevent the neurotoxicity of strychnos alkaloids. Based on the previous studies of our research team, 21 endogenous substances related to neurotoxicity were monitored in rats' serum with HPLC-MS/MS and ELISA. Starting from these fundamentals, a Lasso-Logistic regression model was used to select efficient biomarkers from 21 endogenous substances to predict brain injury and verify the neuroprotective effect of peonies. Under the processing of the Lasso-Logistic regression model, 12 biomarkers were identified from 21 endogenous substances to predict the neurotoxicity induced by strychnos alkaloids. At the same time, the neuroprotective effect of peonies was further confirmed by evaluating the level of 12 biomarkers. The results indicated that the development of the Lasso-Logistic regression model would provide a new, simple and efficient method for the prediction and diagnosis of the neurotoxicity induced by strychnos alkaloids.

Effects of enzymatic free fatty acid reduction process on the composition and phytochemicals of rice bran oil.

The effects of enzymatic free fatty acid reduction process (EFFARP) on the composition and phytochemicals of dewaxed and degummed rice bran oil (DDRBO) were investigated and compared with the effects observed using internal acyl acceptors. The acid value of DDRBO was effectively decreased from 16.99 mg KOH/g to approximately 0.36 mg KOH/g by EFFARP. EFFARP significantly decreased the moisture content and peroxide value of DDRBO and increased the induction period. The Sn-2 fatty acid comoposition of DDRBO after EFFARP was very reaching the total fatty acid composition. EFFARP significantly increased the triacylglycerol content compared to the control, while the oryzanol content was not obviously affected. The contents of free sterol, and total tocopherol and tocotrienol were increased slightly by EFFARP compared to the control. When conducted under vacuum with added nitrogen, EFFARP shows great application potential in the edible oil industry.

Identification of a Novel c-Myc Inhibitor 7594-0037 by Structure-Based Virtual Screening and Investigation of Its Anti-Cancer Effect on Multiple Myeloma.

INTRODUCTION: Multiple myeloma (MM) is an extremely malignant and incurable hematological cancer. Increased expression of the c-Myc oncoprotein is closely associated with shorter overall survival of MM patients, implying that c-Myc is a potential therapeutic target. MAIN METHODS: We identified a potential c-Myc inhibitor 7594-0037 by structure-based virtual screening from the ChemDiv database. CCK8 assay and flow cytometry were used to detect MM cell viability, cell cycle and apoptosis. Q-PCR and Western blot were used to measure corresponding mRNA and protein expression levels. Protein stability assay measured the stability of c-Myc. RESULTS: Compound 7594-0037 exhibited stronger anti-proliferative activity against MM cells, and induced MM cell cycle G2 phase arrest and apoptosis. More importantly, compound 7594-0037 overcame myeloma resistance to bortezomib and exhibited a synergistic effect with bortezomib, resulting in increased MM cell death. The mechanism consists of compound 7594-0037 facilitating c-Myc protein degradation via decreasing the c-Myc S62 phosphorylation levels mediated by PIM1 kinase. Molecular dynamics simulation with the c-Myc/7594-0037 complex showed that compound 7594-0037 bound tightly to the N-terminus of c-Myc, and blocked the binding interaction of the two termini of c-Myc, which resulted in c-Myc entering into an unstable state. CONCLUSION: Overall, our study provides preliminary data for compound 7594-0037, which can be used as a novel c-Myc inhibitor and is a potential candidate therapeutic drug for multiple myeloma.

Carboxymethyl chitosan-decorated proliposomes as carriers for improved stability and sustained release of flaxseed oil.

A flaxseed oil carboxymethyl chitosan-decorated proliposome system was fabricated in this research. The physicochemical characteristics, stability, and in vitro release behaviors of flaxseed oil were studied and compared with that of flaxseed oil-loaded liposomes. The results of dynamic light scattering, transmission electron microscopy, and oxidation stability indicated that the storage stability of proliposomes was better. After 28 days of storage, the peroxide value of flaxseed oil-loaded liposomes (20.1 meq/kg) was significantly (P < 0.05) higher than that of flaxseed oil-loaded proliposomes (9.0 meq/kg); the thiobarbituric acid reactive substances in the former (0.53 mmol/kg) was also higher than that in the latter (0.27 mmol/kg). The in vitro release behavior of flaxseed oil indicated the proliposomes were more stable in the simulated gastrointestinal fluids. Therefore, the flaxseed oil-loaded proliposome system could be a promising vehicle for delivery flaxseed oil in food industry. PRACTICAL APPLICATION: A flaxseed oil-loaded proliposome delivery system was fabricated in this research. Their physical and oxidation stability of flaxseed oil were improved, and the in vitro cumulative release of flaxseed oil was delayed compared with flaxseed oil liposomes. This system may provide an effective strategy for the flaxseed oil encapsulation in the food industry.

Neuroprotective effect of total glycosides from paeonies against neurotoxicity induced by strychnos alkaloids related to recovering the levels of neurotransmitters and neuroendocrine hormones in rat serum and brain.

Semen Strychni, a classical traditional Chinese medicine, has been widely used for its anti-tumor, analgesic and anti-inflammatory angiogenesis effects. However, taking an overdose of Semen Strychni might result in extreme neurotoxicity. Strychnos alkaloids are the main toxic constituents of Semen Strychni. Total glycosides from paeonies are considered to have neuroprotective effects. In this study, twelve potential endogenous biomarkers in rat serum and brain were monitored to investigate the protective effect of total glycosides from the paeony against strychnos alkaloids-induced neurotoxicity. A sensitive liquid chromatography-tandem mass spectrometry method was developed and validated to monitor eight neurotransmitters including glutamate, γ-aminobutyric acid, acetylcholine serotonin, dopamine, norepinephrine, tryptophan and tyrosine. An enzyme-linked immunosorbent assay method was selected for determination of four neuroendocrine hormones including thyrotrophin-releasing hormone, corticotrophin-releasing hormone, antidiuretic hormone and prolactin. Results showed that continuous administration of strychnos alkaloids for 15 days caused significant changed levels of the biomarkers (especially the four neuroendocrine hormones). Meanwhile, total glycosides from paeony pretreated rats (administrated with total glycosides from the paeony for 15 days before exposure to strychnos alkaloids) showed recovered levels of these biomarkers. The results suggested that the neurotransmitters and neuroendocrine hormones in serum and brain might play potential roles as biomarkers. This study provides the possibility of alleviating the Semen Strychni-induced neurotoxicity in clinic by pre-protection with total glycosides from paeonies.

Identification of chemical components in Baidianling Capsule based on gas chromatography-mass spectrometry and high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry.

Baidianling Capsule, which is made from 16 Chinese herbs, has been widely used for treating vitiligo clinically. In this study, the sensitive and rapid method has been developed for the analysis of chemical components in Baidianling Capsule by gas chromatography-mass spectrometry in combination with retention indices and high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry. Firstly, a total of 110 potential volatile compounds obtained from different extraction procedures including alkanes, alkenes, alkynes, ketones, ethers, aldehydes, alcohols, phenols, organic acids, esters, furans, pyrrole, acid amides, heterocycles, and oxides were detected from Baidianling Capsule by gas chromatography-mass spectrometry, of which 75 were identified by mass spectrometry in combination with the retention index. Then, a total of 124 components were tentatively identified by high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry. Fifteen constituents from Baidianling Capsule were accurately identified by comparing the retention times with those of reference compounds, others were identified by comparing the retention times and mass spectrometry data, as well as retrieving the reference literature. This study provides a practical strategy for rapidly screening and identifying the multiple constituents of a complex traditional Chinese medicine.

The analgesic effect of trans-resveratrol is regulated by calcium channels in the hippocampus of mice.

Resveratrol has been widely studied in terms of it's potential to slow the progression of many diseases. But little is known about the mechanism of action in neuropathic pain. Neuropathic pain is the main type of chronic pain associated with tissue injury. Calcium channels and calcium/caffeine-sensitive pools are associated with analgesic pathway involving neuropathic pain. Our previous study suggested that the antinociceptive effect of resveratrol was involved in Ca2+/calmodulin-dependent signaling in the spinal cord of mice. The aim of this study was to explore the involvement of Ca2+ in analgesic effects of trans-resveratrol in neuropathic pain and signal pathway in hippocampus. Hot plate test was used to assess antinociceptive response when mice were treated with trans-resveratrol alone or in combination with Mk 801, nimodipine, CaCl2, ryanodine or EGTA. The effects of trans-resveratrol and the combination on Ca2+/calmodulin-dependent protein kinase II (CaMKII) and BDNF (brain-derived neurotrophic factor) expression in hippocampus were also investigated. The results showed that trans-resveratrol increased paw withdraw latency in the hot plate test. The effect of resveratrol was enhanced by Mk 801 and nimodipine. Central administration of Ca2+, however, abolished the antinociceptive effects of resveratrol. In contrast, centrally administered EGTA or ryanodine improved trans-resveratrol induced antinociception. There was a significant increase in p-CaMKII and BDNF expression in the hippocampus when resveratrol were combined with Mk 801, nimodipine, ryanodine and EGTA. Administration of CaCl2 blocked changes in p-CaMKII and BDNF levels in the hippocampus. These findings suggest that trans-resveratrol exerts the effects of antinociception through regulation of calcium channels and calcium/caffeine-sensitive pools.

Hyperbaric oxygen treatment and enteral nutrition support with glutamine relieves traumatic brain injury in the rats.

The abnormal metabolic processes following traumatic brain injury (TBI) have been proposed to contribute to secondary injuries after TBI. Therefore, enteral nutrition (EN) support for TBI patients has received more attention. This study aimed to evaluate the complimentary effects of enteral nutrition with glutamine and hyperbaric oxygen (HBO) on the recovery of TBI. TBI model was established in SD rats, which were randomly divided into four groups: TBI, TBI + HBO, TBI + GLN, and TBI + HBO + GLN. Neuronal apoptosis in penumbra area was detected by TUNEL. Serum prealbumin level was detected by ELISA. Motor function was evaluated by beam-balance test. We found that the body weight of the rats had no significant differences in different groups before and after injury. Among the four groups, beam-balance test score was the lowest, serum prealbumin level was the highest, and neuronal apoptosis rate was the lowest in TBI + HBO + GLN group on day 3 and 7 after TBI. In conclusion, our data suggest that hyperbaric oxygen combined with enteral nutrition support with glutamine is effective in reducing neuronal apoptosis, increasing serum prealbumin concentration and improving neurological function after TBI injury.

Synergistic effect of combination topotecan and chronomodulated radiation therapy on xenografted human nasopharyngeal carcinoma.

PURPOSE: To investigate the in vivo chronomodulated radiosensitizing effect of topotecan (TPT) on human nasopharyngeal carcinoma (NPC) and its possible mechanisms. METHODS AND MATERIALS: Xenografted BALB/c (nu/nu) NPC mice were synchronized with an alternation of 12 hours of light from 0 to 12 hours after light onset (HALO) and 12 hours of darkness to establish a unified biological rhythm. Chronomodulated radiosensitization of TPT was investigated by analysis of tumor regrowth delay (TGD), pimonidazole hydrochloride, histone H2AX phosphorylation, (γ-H2AX) topoisomerase I (Top I), cell cycle, and apoptosis after treatment with (1) TPT (10 mg/kg) alone; (2) radiation therapy alone (RT); and (3) TPT+RT at 3, 9, 15, and 21 HALO. The tumor-loaded mice without any treatment were used as controls. RESULTS: The TPT+RT combination was more effective than TPT or RT as single agents. The TPT+RT combination at 15 HALO was best (TGD = 58.0 ± 3.6 days), and TPT+RT at 3 HALO was worst (TGD = 35.0 ± 1.5 days) among the 4 TPT+RT groups (P<.05). Immunohistochemistry analysis revealed a significantly increased histone H2AX phosphorylation expression and decreased pimonidazole hydrochloride expression in the TPT+RT group at the same time point. The results suggested that the level of tumor hypoxia and DNA damage varied in a time-dependent manner. The expression of Top I in the TPT+RT group was also significantly different from the control tumors at 15 HALO (P<.05). Cell apoptosis index was increased and the proportion of cells in S phase was decreased (P<.05) with the highest value in 15 HALO and the lowest in 3 HALO. CONCLUSIONS: This study suggested that TPT combined with chronoradiotherapy could enhance the radiosensitivity of xenografted NPC. The TPT+RT group at 15 HALO had the best therapeutic effect. The chronomodulated radiosensitization mechanisms of TPT might be related to circadian rhythm of tumor hypoxia, cell cycle redistribution, DNA damage, and expression of Top I.

Ultrasound effects on the degradation kinetics, structure and rheological properties of apple pectin.

The effects of ultrasound on the molecular weight of apple pectin were investigated. The structure and rheological properties of the degradation products were also tentatively identified by High Performance Liquid Chromatography-Photodiode Array Detector (HPLC-PAD), Infrared spectroscopy (IR), Nuclear Magnetic Resonance spectroscopy (NMR) and Rheometer. The results indicated that the weight-average molecular weight of apple pectin decreased obviously after ultrasound treatment. The molecular weight of degradation products had a uniform and narrow distribution. Ultrasound intensity and temperature play an important role in the degradation reaction. Degradation kinetics model of apple pectin fitted to 1/M(t) - 1/M(0) = kt from 5 to 45 °C. The degree of methylation of apple pectin reduced according to IR analysis when ultrasound was applied. Ultrasound treatment could not alter the primary structure of apple pectin according to the results determined by HPLC, IR and NMR. Meanwhile, the viscosity of apple pectin was 10(3) times as large as that of ultrasound-treated apple pectin. The ultrasound-treated apple pectin showed predominantly viscous responses (G' < G") over the same frequency range. The results suggested that ultrasound provided a viable alternative method for the modification of pectin.

Physicochemical properties, firmness, and nanostructures of sodium carbonate-soluble pectin of 2 Chinese cherry cultivars at 2 ripening stages.

Firmness and physicochemical properties of 2 Chinese cherry (Prunus pseudocerasus L.) cultivars (soft cultivar "Caode" and crisp cultivar "Bende") at unripe and ripe stages were investigated, and the qualitative and quantitative information about sodium carbonate-soluble pectin (SSP) nanostructures was determined by atomic force microscopy (AFM). The lengths and widths of the cherry SSPs are very regular: almost all of the widths and lengths of SSP single molecules are composed of several basic units. The widths of the SSP chains are 37, 47, 55, and 61 nm, and the lengths are 123, 202, and 380 nm in both cultivars. The results show that the firmer cherry groups (crisp fruit) contain more percentages of wide and short SSP chains than soft fruit, and the unripe groups contain more percentages of wide and long SSP chains than corresponding ripe groups. They indicate that those nanostructural characteristics of SSP are closely related with firmness of the Chinese cherries in each cultivar.