Protective effect of soluble dietary fiber from Rosa roxburghii Tratt residue on dextran sulfate sodium-induced ulcerative colitis by regulating serum metabolism and NF-κB pathway in mice.

BACKGROUND: Ulcerative colitis (UC) refers to an idiopathic chronic inflammatory bowel disease that start with inflammation of the intestinal mucosa. Dietary fiber plays a crucial role in maintaining the normal architecture of the intestinal mucosa. In this study, the protective effect and potential mechanism of soluble dietary fiber from Rosa roxburghii Tratt residue (SDFR) on dextran sulfate sodium (DSS)-induced UC mice were explored. RESULTS: The results revealed that SDFR could ameliorate the body weight loss and pathological injury, improve the structure and crypt destruction in colon in DSS-induced mice. Moreover, the levels of NO, IL-1ß, TNF-α, MPO, and protein expression of iNOS and COX-2 were decreased after administration of SDFR. Notably, nontargeted metabolomics analysis indicated that there were significant differences in 51 potential metabolites in serum between the DSS and control groups. SDFR intervention could regulate aberrant alterations of these metabolites and mitigate UC via regulating metabolic pathway, including arachidonic acid and glycerophospholipid metabolism. CONCLUSION: This study provides novel evidence that SDFR could be used as a potential modulator to relieve the UC, and also the results provide theoretical basis for the utilization of by-products in Rosa roxburghii Tratt fruit processing. This article is protected by copyright. All rights reserved.

Natural product Kaji-ichigoside F1 exhibits rapid antidepression via activating the AMPA-BDNF-mTOR pathway and inhibiting the NMDAR-CaMKIIα pathway.

BACKGROUND: Depression is a common and recurrent neuropsychiatric disorder. Recent studies have shown that the N-methyl-d-aspartate (NMDA) receptor (NMDAR) is involved in the pathophysiology of depression. Previous studies have found that Kaji-ichigoside F1 (KF1) has a protective effect against NMDA-induced neurotoxicity. However, the antidepressant mechanism of KF1 has not been confirmed yet. PURPOSE: In the present study, we aimed to evaluate the rapid antidepressant activity of KF1 and explore the underlying mechanism. STUDY DESIGN: First, we explored the effect of KF1 on NMDA-induced hippocampal neurons and the underlying mechanism. Second, depression was induced in C57BL/6 mice via chronic unpredictable mild stress (CUMS), and the immediate and persistent depression-like behavior was evaluated using the forced swimming test (FST) after a single administration of KF1. Third, the contributions of NMDA signaling to the antidepressant effect of KF1 were investigated using pharmacological interventions. Fourth, CUMS mice were treated with KF1 for 21 days, and then their depression-like behaviors and the underlying mechanism were further explored. METHODS: The FST was used to evaluate immediate and persistent depression-like behavior after a single administration of KF1 with or without NMDA pretreatment. The effect of KF1 on depressive-like behavior was investigated in CUMS mice by treating them with KF1 once daily for 21 days through the sucrose preference test, FST, open field test, and tail suspension test. Then, the effects of KF1 on the morphology and molecular and functional phenotypes of primary neuronal cells and hippocampus of mice were investigated by hematoxylin-eosin staining, Nissl staining, propidium iodide staining, TUNEL staining, Ca2+ imaging, JC-1 staining, ELISA, immunofluorescence analysis, RT-PCR, and Western blot. RESULTS: KF1 could effectively improve cellular viability, reduce apoptosis, inhibit the release of LDH and Ca2+, and increase the mitochondrial membrane potential and the number of dendritic spines numbers in hippocampal neurons. Moreover, behavioral tests showed that KF1 exerted acute and sustained antidepressant-like effects by reducing Glu-levels and ameliorating neuronal damage in the hippocampus. Additionally, in vivo and in vitro experiments revealed that PSD95, Syn1, α-amino-3­hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), and brain-derived neurotrophic factor (BDNF) were upregulated at the protein level, and BDNF and AMPA were upregulated at the mRNA level. NR1 and NR2A showed the opposite trend. CONCLUSION: These results confirm that KF1 exerts rapid antidepressant effects mainly by activating the AMPA-BDNF-mTOR pathway and inhibiting the NMDAR-CaMKIIα pathway. This study serves as a new reference for discovering rapid antidepressants.

Potential antiplatelet aggregation metabolites from the discarded sorghum (Sorghum bicolor L.) root.

Sorghum (Sorghum bicolor L.) is the fifth largest crop in the world and has potential health benefits, but vast quantities of sorghum roots are discarded after harvest. Based on the previous antiplatelet aggregation for this species, two new multi-substituted 3H-indole alkaloids sorghumine A (1) and sorghumine B (2), together with 14 known compounds (3-16), were found from the water extract of sorghum roots. Compounds 1-2 were identified by analyzing their spectroscopic data and physic and chemical properties, and the absolute configuration was further determined by electronic circular dichroism (ECD) analysis and calculations. 1-2, 4, 6-8 and 13-15 showed significant inhibition of platelet aggregation induced by adenosine diphosphate. 2-4, 6-9 and 11 showed significant inhibition of platelet aggregation induced by collagen. 4-6, 8, 10-11 and 16 showed significant inhibition on platelet aggregation induced by thrombin. Furthermore, molecular docking showed that active compounds can bind to P2Y12 and COX-1 receptors in platelet.

Anti-depressant-like effect of fermented Gastrodia elata Bl. by regulating monoamine levels and BDNF/NMDAR pathways in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Gastrodia elata Blume (GE) is a Chinese medicinal herb commonly used to treat central nervous system-related diseases, including headaches, dizziness, epilepsy, numbness of the limbs and depression. AIM OF THE STUDY: Microbial-based fermentation has been successfully used to increase the extract efficiency of medicinal herbs in recent years. However, no study has hitherto explored the anti-depressant-like effect of GE processed by microorganisms. Herein, this subject aimed to clarify the anti-depressant-like effect of fermented Gastrodia elata Bl. (FGE) and its active chemical constituents. MATERIALS AND METHODS: The chronic unpredictable mild stress (CUMS) model, a well-established animal model of depression, was induced in Kunming (KM) mice. The mice were administrated with FGE for 3 weeks. The sucrose preference test (SPT), open field test (OFT) and tail suspension test (TST) were conducted. Moreover, the levels of serotonin (5-HT) and dopamine (DA) in brain tissue homogenates, the concentration of Ca2+ and the activity of MAO in serum, H&E and Nissl staining in the hippocampus, and the hippocampus protein expressions of BDNF, NMDAR1, NMDAR2A and NMDAR2B relevant to depression were detected. Furthermore, chemical constituents of FGE were further isolated, and the protective activity of the obtained compounds against NMDA-induced PC-12 cell damage was assessed. RESULTS: FGE could alleviate the depression state in CUMS-induced mice and reduce apoptosis of neuronal cells in the hippocampus. Furthermore, FGE could improve the contents of 5-HT, DA and decrease the concentration of Ca2+ and MAO activity in brain tissue and serum compared with the control group. It could reverse the decreased expression of BDNF, NMDAR2A and NMDAR2B and increase NMDAR1 protein expression. Investigation of the active constituents from FGE yielded two new compounds, (4-(((4-ethoxybenzyl) oxy)methyl)-phenol 1 and 3-((4-hydroxy benzyl)oxy)propane-1,2-diol) 2, with twelve known compounds (3-14). The compounds (3-((4-hydroxybenzyl)oxy)propane-1,2-diol 2, 4, 4'-dihydroxyd iphenyl methane 3, and bungein A 4) protected against NMDA-induced PC-12 cells damage. CONCLUSION: This study demonstrated that FGE could improve the depressive behavior of CUMS-induced mice and exert a protective effect on nerve cells in the brain. Importantly, compounds 2-4 are the active components of FGE. Overall, the above findings suggest that FGE has huge prospects for application in treating depression-related diseases.

Neuroprotection of Kaji-Ichigoside F1 via the BDNF/Akt/mTOR Signaling Pathways against NMDA-Induced Neurotoxicity.

Kaji-ichigoside F1 (KF1), a natural oleanane-type triterpenoid saponin, is the main active constituent from Rosa roxburghii. In the southwest regions of China, particularly in Guizhou Province, this plant was used as a Miao ethnic medicine to prevent and treat dyspepsia, dysentery, hypoimmunity, and neurasthenia. In the present study, the neuroprotective effect of KF1 was evaluated against N-methyl-D-aspartate (NMDA)-induced neurotoxicity in vivo and in vitro. An NMDA-induced PC12 cell neurotoxicity assay showed that KF1 effectively improved cellular viability, inhibited the release of lactate dehydrogenase (LDH), and reduced cell apoptosis. Furthermore, KF1-treated NMDA-induced excitotoxicity mice displayed a remarkable capacity for improving spatial learning memory in the Y-maze and Morris water maze tests. In addition, KF1 increased the levels of the neurotransmitters 5-hydroxytryptamine, dopamine, and monoamine oxidase and reduced the calcium ion concentration in the hippocampus of mice. Hematoxylin and eosin and Nissl staining indicated that KF1 effectively reduced the impairment of neurons. Furthermore, Western blot assays showed that KF1 decreased NMDAR1 expression. In contrast, the NMDAR2B (NR2B), glutamate receptor (AMPA), TrkB, protein kinase B (AKT), mammalian target of rapamycin (mTOR), PSD95, and synapsin 1 were upregulated in NMDA-induced PC12 cells and an animal model. These results suggest that KF1 has a remarkable protective effect against NMDA-induced neurotoxicity, which is directly related to the regulation of the NMDA receptor and the activation of the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) and BDNF/AKT/mTOR signaling pathways.

Engineering the Thermostability of the Mono- and Diacylglycerol Lipase SMG1 for the Synthesis of Diacylglycerols.

Diacylglycerols (DAGs) display huge application prospectives in food industries. Therefore, new strategies to produce diacylglycerides are needed. Malassezia globose lipase (SMG1) could be used to synthesize DAGs. However, the poor thermostability of SMG1 seriously hampers its application. Herein, a rational design was used to generate a more thermostable SMG1. Compared with the wild type (WT), the M5D mutant (Q34P/A37P/M176V/G177A/M294R/ G28C-P206C), which contains five single-point mutations and one additional disulfide bond, displayed a 14.0 °C increase in the melting temperature (Tm), 5 °C in the optimal temperature, and 1154.3-fold in the half-life (t1/2) at 55 °C. Meanwhile, the specific activity towards DAGs of the M5D variant was improved by 3.0-fold compared to the WT. Molecular dynamics (MD) simulations revealed that the M5D mutant showed an improved rigid structure. Additionally, the WT and the M5D variants were immobilized and used for the production of DAGs. Compared with the WT, the immobilized M5D-catalyzed esterification showed a 9.1% higher DAG content and a 22.9% increase in residual activity after nine consecutive cycles. This study will pave the way for the industrial application of SMG1.

Improving Both the Thermostability and Catalytic Efficiency of Phospholipase D from Moritella sp. JT01 through Disulfide Bond Engineering Strategy.

Mining of Phospholipase D (PLD) with high activity and stability has attracted strong interest for investigation. A novel PLD from marine Moritella sp. JT01 (MsPLD) was biochemically and structurally characterized in our previous study; however, the short half-life time (t1/2) under its optimum reaction temperature seriously hampered its further applications. Herein, the disulfide bond engineering strategy was applied to improve its thermostability. Compared with wild-type MsPLD, mutant S148C-T206C/D225C-A328C with the addition of two disulfide bonds exhibited a 3.1-fold t1/2 at 35 °C and a 5.7 °C increase in melting temperature (Tm). Unexpectedly, its specific activity and catalytic efficiency (kcat/Km) also increased by 22.7% and 36.5%, respectively. The enhanced activity might be attributed to an increase in the activation entropy by displacing more water molecules by the transition state. The results of molecular dynamics simulations (MD) revealed that the introduction of double disulfide bonds rigidified the global structure of the mutant, which might cause the enhanced thermostability. Finally, the synthesis capacity of the mutant to synthesize phosphatidic acid (PA) was evaluated. The conversion rate of PA reached about 80% after 6 h reaction with wild-type MsPLD but reached 78% after 2 h with mutant S148C-T206C/D225C-A328C, which significantly reduced the time needed for the reaction to reach equilibrium. The present results pave the way for further application of MsPLD in the food and pharmaceutical industries.

A New Phospholipase D from Moritella sp. JT01: Biochemical Characterization, Crystallization and Application in the Synthesis of Phosphatidic Acid.

A new phospholipase D from marine Moritella sp. JT01 (MsPLD) was recombinantly expressed and biochemically characterized. The optimal reaction temperature and pH of MsPLD were determined to be 35 °C and 8.0. MsPLD was stable at a temperature lower than 35 °C, and the t1/2 at 4 °C was 41 days. The crystal structure of apo-MsPLD was resolved and the functions of a unique extra loop segment on the enzyme activity were characterized. The results indicated that a direct deletion or fastening of the extra loop segment by introducing disulfide bonds both resulted in a complete loss of its activity. The results of the maximum insertion pressure indicated that the deletion of the extra loop segment significantly decreased MsPLD's interfacial binding properties to phospholipid monolayers. Finally, MsPLD was applied to the synthesis of phosphatidic acid by using a biphasic reaction system. Under optimal reaction conditions, the conversion rate of phosphatidic acid reached 86%. The present research provides a foundation for revealing the structural-functional relationship of this enzyme.

Preparation and Characterization of Calcium-Incorporated Rosa roxburghii Tratt and Its Efficacy on Bone Mineral Density in Rats.

The deficiency of traditional calcium preparation will gradually be replaced by the new type of calcium preparation. Rosa roxburghii fruit (R. roxburghii) is popular for its rich nutrients and functional ingredients. The fermentation broth of R. roxburghii, involving amino acids, flavonoids, triterpenes, polysaccharides, and other compounds, is favorable for calcium chelation. Thus, this study fabricated calcium-incorporated R. roxburghii (FECa) and further illustrated its efficacy on bone mineral density (BMD) in rats. The calcium holding capacity of FECa was identified and confirmed using AAS. Ion complexation of FECa was characterized using 1H-NMR, UV, SEM and EDS, and FTIR. The calcium contents of femurs were increased by 36%, and the bone trabeculae of femurs were significantly increased. Net calcium balance was enhanced to further improve BMD by oral administration of FECa. The above results indicate that FECa can be a potential and efficient calcium supplementation agent.

Glyceryl butyrate attenuates enterotoxigenic Escherichia coli-induced intestinal inflammation in piglets by inhibiting the NF-κB/MAPK pathways and modulating the gut microbiota.

The aims of this study were to evaluate whether a diet supplemented with glyceryl butyrate could attenuate the immune-inflammatory response in piglets challenged with enterotoxigenic Escherichia coli (ETEC), and to explore the mechanisms of its regulation. Eighteen weaning piglets were assigned to three diets: basal diet (CON), antibiotics diet (ATB), and 0.5% glyceryl butyrate diet (GB group). Significantly lower concentrations of IL-1ß, IL-6 and TNF-α in the jejunum and IL-6 in the ileum were observed in the GB group than that in the CON group (P < 0.05). Moreover, a decreasing trend of IL-1ß (P = 0.075) and TNF-α (P = 0.070) was observed in the ileum in the GB group. Correspondingly, the GB group had significantly increased mRNA expression of porcine beta defensins (pBDs) in the jejunum (pBD1, pBD2, pBD114 and pBD129) and ileum (pBD2, pBD3, pBD114 and pBD129) (P < 0.05), and protein abundance of Claudin 1, Occludin, and ZO-1 in the jejunum and ileum (P < 0.05). Further research results showed that the improvement of beta defensins and tight junctions in the GB group was related to the decreased phosphorylation of the NFκB/MAPK pathway. In addition, the results of 16S rDNA sequencing showed that glycerol butyrate supplementation altered the ileal microbiota composition of piglets, increasing the relative abundance of Lactobacillus reuteri, Lactobacillus salivarius, and Lactobacillus agrilis. In summary, glyceryl butyrate attenuated the immune-inflammatory response in piglets challenged with ETEC by inhibiting the NF-κB/MAPK pathways and modulating the gut microbiota, and thus improved piglet intestinal health.

Enhancing thermostability of Yarrowia lipolytica lipase 2 through engineering multiple disulfide bonds and mitigating reduced lipase production associated with disulfide bonds.

The limited thermostability of Yarrowia lipolytica lipase 2 (Lip2) hampers its industrial application. To improve its thermostability, we combined single disulfide bonds which our group identified previously. In this study, combining different regional disulfide bonds had greater effect than combining same regional disulfide bonds. Furthermore, mutants with 4, 5, and 6 disulfide bonds exhibited dramatically enhanced thermostability. Compared with the wild-type, sextuple mutant 6s displayed a 22.53 and 31.23 ℃ increase in the melting temperature (Tm) and the half loss temperature at 15 min (T15 50), respectively, with greater pH stability and a wider reaction pH range. Molecular dynamics simulation revealed that multiple disulfide bonds resulted in more rigid structures of mutants 4s, 5s and 6s, and prolonged enzyme unfolding times. Moreover, secretions of mutants 5s and 6s were significantly increased by 60% and 80% by co-expressing with the chaperone protein disulfide isomerase (PDI), which mitigated the reduced production issue caused by multiple disulfide bonds. Results of this study indicated that enhanced heat endurance giving more potential for industrial application.

High-level expression of Thermomyces dupontii thermo-alkaline lipase in Pichia pastoris under the control of different promoters.

In this study, 15 methanol-inducible and 9 constitutive promoters were used to drive the expression of Thermomyces dupontii lipase (TDL) in Pichia pastoris. Of the 15 methanol-inducible promoters, formaldehyde dehydrogenase promoter (PFLD1) showed the highest efficiency in driving lipase production, followed by alcohol oxidase 1 (PAOX1) and dihydroxyacetone synthase (PDAS1) promoters. The maximum lipase activity of transformants with PFLD1, PAOX1 and PDAS1 promoters in 5-l bioreactor was 27,076, 24,159 and 22,342 U/ml, respectively. For the nine constitutive promoters, glycosyl phosphatidyl inositol-anchored protein promoter (PGCW14) produced the highest amount of lipases in a medium containing glucose or glycerol as the only carbon source, followed by mitochondrial alcohol dehydrogenase isozyme (P0472) and glyceraldehyde-3-phosphate dehydrogenase (PGAP) promoters. The maximum lipase yields in 5-l bioreactors under the control of PGCW14, P0472 and PGAP promoters were 17,353, 15,046 and 14,276 U/ml, respectively. The result of this study not only identifies a few highly efficient promoters for the heterologous expression of TDL in P. pastoris, but also casts some insight into the optimization of protein production in heterologous systems.

Recent progress of porcine milk components and mammary gland function.

As the only nutritional source for newborn piglets, porcine colostrum and milk contain critical nutritional and immunological components including carbohydrates, lipids, and proteins (immunoglobulins). However, porcine milk composition is more complex than these three components. Recently, scientists identified additional and novel components of sow colostrum and milk, including exosomes, oligosaccharides, and bacteria, which possibly act as biological signals and modulate the intestinal environment and immune status in piglets and later in life. Evaluation of these nutritional and non-nutritional components in porcine milk will help better understand the nutritional and biological function of porcine colostrum and milk. Furthermore, some important functions of the porcine mammary gland have been reported in recent published literature. These preliminary studies hypothesized how glucose, amino acids, and fatty acids are transported from maternal blood to the porcine mammary gland for milk synthesis. Therefore, we summarized recent reports on sow milk composition and porcine mammary gland function in this review, with particular emphasis on macronutrient transfer and synthesis mechanisms, which might offer a possible approach for regulation of milk synthesis in the future.