Wenjun Xiao

Effects of yeast culture and fibrolytic enzyme supplementation on in vitro fermentation characteristics of low-quality cereal straws

The effects of yeast culture and fibrolytic enzyme preparation (containing cellulase and xylanase) on in vitro fermentation characteristics of rice straw, wheat straw, maize stover, and maize stover silage were examined using an in vitro gas production technique. Four levels of yeast culture and fibrolytic enzyme supplements (0, 2.5, 5.0, and 7.5 g/kg of straw DM, respectively) were tested in a 4 x 4 factorial arrangement. Supplementation of yeast culture increased the cumulative gas production, theoretical maximum of gas production, rate of gas production, IVDMD, and in vitro OM disappearance (IVOMD), and decreased the lag time for each type of straw. Fibrolytic enzyme supplementation tended to increase cumulative gas production, theoretical maximum of gas production, and rate of gas production; prolonged lag time of gas production; and enhanced IVDMD and IVOMD for 4 types of cereal straws, with the significance of this effect being dependent on the level of supplemented enzymes. There were significant interactions between fibrolytic enzymes and yeast on all in vitro gas production parameters, IVDMD, and IVOMD of each type of straw. The outcome of this research indicated that the application of fibrolytic enzyme preparation and yeast culture could improve in vitro gas production fermentation of cereal straws.

L-Theanine Improves Immunity by Altering TH2/TH1 Cytokine Balance, Brain Neurotransmitters, and Expression of Phospholipase C in Rat Hearts

Background This study aimed to investigate the regulatory effects of L-theanine on secretion of immune cytokines, hormones, and neurotransmitters, and mRNA expression of phospholipase C (PLC) in rats, and to explore its regulatory mechanism in immune function. Material/Methods Sixty-four Sprague-Dawley rats received daily intragastric infusion of different doses of L-theanine solution [0, 50 (LT), 200 (MT), and 400 (HT) mg/kg BW]. Cytokines, immunoglobulins, and hormones in the serum, neurotransmitters, and mRNA expression of PLC in the relevant tissues were assayed. Results L-theanine administration increased the splenic organ index and decreased the contents of ILs-4/6/10 and the ratio of IL-4/IFN-γ in the serum. High-dose L-theanine administration increased the levels of dopamine and 5-hydroxytryptamine in the pituitary and hippocampus, resulting in decrease in corticosterone level in the serum. L-theanine administration decreased the mRNA expressions of PLC isomers in the liver and PLC-γ1 and PLC-δ1 in the spleen. Interestingly, mRNA expressions of PLC-βf1 in the spleen and PLC isomers mRNA in the heart were up-regulated by L-theanine administration. Conclusions Administration of 400 mg/kg BWL-theanine improved immune function of the rats by increasing the splenic weight, altering the Th2/Th1 cytokine balance, decreasing the corticosterone level in the serum, elevating dopamine and 5-hydroxytryptamine in the brain, and regulating the mRNA expression of PLC isomers in the heart.

Magnolol and honokiol regulate the calcium-activated potassium channels signaling pathway in Enterotoxigenic Escherichia coli-induced diarrhea mice.

To explore the regulatory mechanisms of magnolol and honokiol on calcium-activated potassium channels signaling pathway in Enterotoxigenic Escherichia coli (ETEC)-induced diarrhea mice, the concentrations of serum chloride ion (Cl(-)), sodium ion (Na(+)), potassium ion (K(+)) and calcium ion (Ca(2+)) were measured. Additionally, the mRNA expressions of calmodulin 1 (CaM), calcium/calmodulin-dependent protein kinase II alpha subunit (CaMKIIα) and beta subunit (CaMKIIβ), ryanodine receptor 1, inositol 1,4,5-trisphosphate receptors (IP3 receptors), protein kinases C (PKC), potassium intermediate/small conductance calcium-activated channels (SK) and potassium large conductance calcium-activated channels(BK)were determined. A diarrhea mouse model was established using ETEC suspensions (3.29×10(9)CFU/ml) at a dosage of 0.02ml/g live body weight (BW). Magnolol or honokiol was intragastrically administered at dosages of 100 (M100 or H100), 300 (M300 or H300) and 500 (M500 or H500) mg/kg BW according to a 3×3 factorial arrangement. Magnolol and honokiol increased the Cl(-) and K(+) concentrations, further, upregulated the CaM, BKα1 and BKβ3 mRNA levels but downregulated the IP3 receptors 1, PKC, SK1, SK2, SK3, SK4 and BKβ4 mRNA expressions. Magnolol and honokiol did not alter the CaMKIIα, CaMKIIβ, ryanodine receptor 1, IP3 receptor 2, IP3 receptor 3, BKβ1 and BKβ2 mRNA expressions. These results clarify that magnolol and honokiol, acting through Ca(2+) channel blockade, inhibit the activation of IP3 receptor 1 to regulate the IP3-Ca(2+) store release, activate CaM to inhibit SK channels, and effectively suppress PKC kinases to promote BKα1 and BKβ3 channels opening and BKβ4 channel closing, which modulates the intestinal ion secretion.

General Machine Learning Model, Review, and Experimental-Theoretic Study of Magnolol Activity in Enterotoxigenic Induced Oxidative Stress

This study evaluated the antioxidative effects of magnolol based on the mouse model induced by Enterotoxigenic Escherichia coli (E. coli, ETEC). All experimental mice were equally treated with ETEC suspensions (3.45×109 CFU/ml) after oral administration of magnolol for 7 days at the dose of 0, 100, 300 and 500 mg/kg Body Weight (BW), respectively. The oxidative metabolites and antioxidases for each sample (organism of mouse) were determined: Malondialdehyde (MDA), Nitric Oxide (NO), Glutathione (GSH), Myeloperoxidase (MPO), Catalase (CAT), Superoxide Dismutase (SOD), and Glutathione Peroxidase (GPx). In addition, we also determined the corresponding mRNA expressions of CAT, SOD and GPx as well as the Total Antioxidant Capacity (T-AOC). The experiment was completed with a theoretical study that predicts a series of 79 ChEMBL activities of magnolol with 47 proteins in 18 organisms using a Quantitative Structure- Activity Relationship (QSAR) classifier based on the Moving Averages (MAs) of Rcpi descriptors in three types of experimental conditions (biological activity with specific units, protein target and organisms). Six Machine Learning methods from Weka software were tested and the best QSAR classification model was provided by Random Forest with True Positive Rate (TPR) of 0.701 and Area under Receiver Operating Characteristic (AUROC) of 0.790 (test subset, 10-fold crossvalidation). The model is predicting if the new ChEMBL activities are greater or lower than the average values for the magnolol targets in different organisms.

l -Theanine prevents ETEC-induced liver damage by reducing intrinsic apoptotic response and inhibiting ERK1/2 and JNK1/2 signaling pathways

Abstract l‐Theanine (LTA; &ggr;‐glutamylethylamide), a peculiar non‐protein‐derived amino acid isolated from tea, is widely used as a functional ingredient and dietary supplement. l‐Theanine has been confirmed to have hepatoprotective effects, but the underlying mechanism remains unknown. This study investigated the protective effect of l‐Theanine‐in vivo, using an enterotoxigenic Escherichia coli (ETEC)‐infected mouse model. l‐Theanine significantly decreased the elevated serum activities of both aspartate aminotransferase (AST) and alanine aminotransferase (ALT), two biomarkers of hepatic impairment. This was consistent with histopathological images from the microscopic observation of liver tissue. In addition, l‐theanine significantly increased the mRNA and protein expression of Bcl‐2 and decreased the expression of Bax, anti‐ and pro‐apoptotic molecules, respectively, compared with levels in the ETEC control group. The expression of cleaved caspase‐3 protein in the group pre‐treated with l‐theanine was significantly lower than that in the ETEC group. Additionally, decreases in extracellular signal‐regulated kinase (ERK1/2) and c‐Jun NH2‐terminal kinase(JNK1/2) MAPK phosphorylation were observed in the l‐theanine pre‐treated group. Our study demonstrates that l‐theanine possesses anti‐apoptotic activity, which can be attributed to suppression of the intrinsic mitochondria‐mediated apoptosis and MAPK phosphorylation signaling pathways.

Alteration of Mevalonate Pathway in Rat Splenic Lymphocytes: Possible Role in Cytokines Secretion Regulated by L-Theanine

L-Theanine is a nonprotein amino acid in tea, and its immunomodulatory function has been confirmed. This study aimed to investigate the effect of L-theanine addition on cytokines secretion in rat splenic lymphocytes and explore its potential immunomodulatory effects on the mevalonate biosynthetic pathway. Our results showed that L-theanine treatment did not influence the proliferation and division indexes of the splenic lymphocytes subsets. Interestingly, L-theanine treatment had regulated the contents of IFN-γ, IL-2, IL-4, IL-10, IL-12, and TNF-α  (P < 0.001) except IL-6 and upregulated the mRNA and protein expression of Ras-related protein Rap-1A (Rap1A), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), and farnesyl diphosphate synthase (FDPs) (P < 0.001). Additionally, there was a positive correlation between Rap1A and HMGCR proteins expression and IFN-γ, IL-4, and IL-6 levels. In conclusion, L-theanine regulated the secretion of cytokines probably by activating expression of Rap1A and HMGCR proteins involved in the mevalonate biosynthetic pathway in rat splenic lymphocytes. Therefore, L-theanine might be a promising potential drug candidate as immunopotentiator.

Effect of tea catechins on regulation of cell proliferation and antioxidant enzyme expression in H2O2-induced primary hepatocytes of goat in vitro

Tea catechins (TC) are polyphenols that have potent antioxidant activity. The objectives of this study were to determine the effects of TC on antioxidant status of hepatocytes challenged with H2 O2 . Primary hepatocytes of goat were exposed to 1 mm H2 O2 without or with 5, 50 and 500 μg/ml TC. The cells were harvested at 48 h post-treatment to determine effects of TC on proliferation, apoptotic features and membrane integrity of cells, and expression of genes and activities of antioxidant enzymes. H2 O2 exposure caused damage to cells (p < 0.001). A lower concentration of TC (5 μg/ml) displayed a protective effect by inhibiting exorbitant cell proliferation and DNA degradation. Both H2 O2 exposure and TC pre-incubation affected expression of antioxidant enzymes at mRNA and protein levels (p < 0.001). The activities of catalase (CAT) (p = 0.027), CuZn-superoxide dismutase (CuZn-SOD) (p < 0.001) and glutathione peroxidase (GPx) (p < 0.001) increased with TC pre-incubation followed by H2 O2 challenge. Changes of CuZn-SOD activity induced by H2 O2 and TC basically paralleled the changes in the corresponding mRNA and protein levels, but the correlation in CAT and GPx expression displayed slightly different patterns at different concentrations of TC. These findings infer that oxidative stress can induce deleterious cellular responses and this unfavourable condition may be alleviated by treatment with TC.