[Jujubae Fructus alleviates intestinal injury caused by toxic medicinals in Shizao Decoction based on correlation between intestinal flora and host metabolism].

Genkwa Fols, Kansui Radix, and Euphorbiae Pekinensis Radix in Shizao Decoction(SZD) are toxic to intestinal tract. Jujubae Fructus in this prescription can alleviate the toxicity, but the mechanism is still unclear. Therefore, this study aims to explore the mechanism. To be specific, 40 normal Sprague-Dawley(SD) rats were classified into the normal group, high-dose and low-dose SZD groups, and high-dose and low-dose SZD without Jujubae Fructus(SZD-JF) groups. The SZD groups were given(ig) SZD, while SZD-JF groups received the decoction without Jujubae Fructus. The variation of body weight and spleen index were recorded. The patho-logical changes of intestinal tissue were observed based on hematoxylin and eosin(HE) staining. The content of malondialdehyde(MDA) and glutathione(GSH) and activity of superoxide dismutase(SOD) in intestinal tissue were measured to evaluate the intestinal injury. Fresh feces of rats were collected to detect intestinal flora structure by 16S ribosomal RNA gene(16S rDNA) sequencing technology. The content of fecal short chain fatty acids and fecal metabolites was determined by gas chromatography-mass spectrometer(GC-MS) and liquid chromatography-mass spectrometer ultra-fast liquid chromatography-quadrupole-time-of-flight mass spectrometer(UFLC-Q-TOF-MS), separately. Spearman's correlation analysis was employed to analyze the differential bacteria genera and differential metabolites. RESULTS:: showed that high-dose and low-dose SZD-JF groups had high content of MDA in intestinal tissue, low GSH content and SOD activity, short intestinal villi(P<0.05), low diversity and abundance of intestinal flora, variation in the intestinal flora structure, and low content of short chain fatty acids(P<0.05) compared with the normal group. Compared with high-dose and low-dose SZD-JF groups, high-dose and low-dose SZD groups displayed low content of MDA in intestinal tissue, high GSH content and SOD activity, recovery of the length of intestinal villi, increased abundance and diversity of intestinal flora, alleviation of dysbacteria, and recovery of the content of short chain fatty acids(P<0.05). According to the variation of intestinal flora and fecal metabolites after the addition of Jujubae Fructus, 6 differential bacterial genera(Lactobacillus, Butyricimonas, Clostridia＿UCG-014, Prevotella, Escherichia-Shigella, Alistipes),4 differential short chain fatty acids(such as acetic acid, propionic acid, butyric acid, valeric acid) and 18 differential metabolites(such as urolithin A, lithocholic acid, and creatinine) were screened out. Beneficial bacteria such as Lactobacillus were in positive correlation with butyric acid and urolithin A(P<0.05). The pathogenic bacteria such as Escherichia-Shigella were in negative correlation with propionic acid and urolithin A(P<0.05). In summary, SZD-JF caused obvious intestinal injury to normal rats, which could lead to intestinal flora disorder. The addition of Jujubae Fructus can alleviate the disorder and relieve the injury by regulating intestinal flora and the metabolites. This study discusses the effect of Jujubae Fructus in relieving the intestinal injury caused by SZD and the mechanism from the perspective of intestinal flora-host metabolism, which is expected to serve as a reference for clinical application of this prescription.

Development of QM/MM (ABEEM polarizable force field) method to simulate the excision reaction mechanism of damaged cytosine.

DNA damages are regarded as having harmful effects on cell. The base excision repair mechanism combats these effects by removing damaged bases. The deglycosylation mechanism of excising damaged bases by DNA glycosylase and the state of the leaving base have been controversial. The enzymatic reaction of DNA glycosylase to remove the damaged bases involves not only the formation and breaking of chemical bonds, but also complex polarization effect and charge transfer, which cannot be accurately simulated by the QM/MM method combined with the fixed charge force field. This work has developed the ABEEM fluctuating polarizable force field combining with the QM method, that is (QM/MM[ABEEM]), to accurately simulate the proton transfer, charge transfer and the charge distribution. The piecewise function is used as the valence-state electronegativity in the QM/MM (ABEEM) to realize the accurate fitting of the charge distribution in reaction. And the charge transfer is accurately simulated by the local charge conservation conditions. Four deglycosylation mechanisms including the monofunctional and difunctional mechanisms of four neutral and protonated cytosine derivatives are explored. It is confirmed that the monofunctional mechanism of Asp-activated nucleophile water is a better deglycosylation mechanism and the base is protonated before the reaction occurs. Protonization of the base reduced the activation energy by 10.00-17.00 kcal/mol. Asp provides the necessary charge for the reaction, and DNA glycosylase preferentially cleaves ɛC. This work provides a theoretical basis for the research of excising damaged bases by DNA glycosylase.

Effects of silencing epididymal vascular endothelial growth factor (VEGF) expression on hyaluronidase (HYD) activity in arsenic poisoning rats through downregulating VEGF receptor 2 (VEGFR2).

RNA interference (RNAi) was used to investigate the role of epididymal vascular endothelial growth factor (VEGF) gene expression on sperm hyaluronidase (HYD) in a rat model of arsenic poisoning and to identify a new gene therapy target for male infertility caused by arsenic poisoning. The Rat model of chronic arsenic poisoning was established. And we found that positive expression of VEGF and VEGF receptor 2 (VEGFR2) was observed by Immunohistochemical staining in the epididymal tissues of arsenic-exposed rats. Subsequently, VEGF-shRNA-1, VEGF-shRNA-2 and VEGF shRNA-3 expression vectors containing epididymal VEGF-shRNA lentivirus were constructed and injected into the bilateral epididymis of each group of rats (Control group, NC-shRNA negative infection group, VEGF-shRNA-1 group, VEGF-shRNA-2 group, VEGF-shRNA-3 group) (n = 10 per group). Compared with the negative infection group and the normal control group, the expression of VEGF and VEGFR2 mRNA and protein levels were significantly decreased following epididymal infection. In addition, the HYD activity was all significantly lower than that in the normal control group and the negative infection group. Taken together, epididymal VEGF gene silencing may inhibit the activity of sperm HYD through downregulating VEGFR2.

The effect of Ureaplasma urealyticum on the level of P34H expression, the activity of hyaluronidase, and DNA fragmentation in human spermatozoa.

BACKGROUND: To study the effect of Ureaplasma urealyticum on the level of P34H expression, the activity of hyaluronidase, and the DNA fragmentation in human spermatozoa. METHOD: Western blot was used to detect the level of P34H expression on spermatozoa.The localization of this protein on human spermatozoa was determined by indirect immunofluorescent and observed by laser scanning confocal microscope. The activity of hyaluronidase was examined by improved fixed-substrate film method. The DNA fragmentation was assayed with the use of TUNEL. RESULTS: There were significant differences in the level of P34H protein expression, the percentage of the P34H-positive rate, the activity of HYD, and the percentage of DNA fragmentation between each infertile group and the control (P<.05). The relation among the P34H protein expression, the percentage of P34H-positive rate and HYD-positive rate, HYD-activity intensity had a significant positive correlation; Both the P34H protein expression and the percentage of P34H-positive rate were inversely correlated with the percentages of sperm DNA fragmentation. CONCLUSION: Ureaplasma urealyticum infection may affect the level of P34H protein expression, the percentage of the P34H-positive rate, the activity of HYD, and DNA fragmentation that influence fertility.

(-)-Epigallocatechin-3-gallate (EGCG) attenuates arsenic-induced cardiotoxicity in rats.

Chronic arsenic exposure in drinking water is associated with the abnormalities of cardiac tissue. Excessive generation of ROS induced by arsenic has a central role in arsenic-induced cardiotoxicity. (-)-Epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in green tea, possesses a potent antioxidant capacity and exhibits extensive pharmacological activities. This study was aim to evaluate the effect of EGCG on arsenic-induced cardiotoxicity in vivo and in vitro. Treatment with NaAsO2 seriously affected the morphology and ultrastructure of myocardium, and induced cardiac injuries, oxidative stress, intracellular calcium accumulation and apoptosis in rats. In consistent with in vivo study, the injuries, oxidative stress and apoptosis were also observed in NaAsO2-treated H9c2 cells. All of these effects induced by NaAsO2 were attenuated by EGCG. These results suggest EGCG could attenuate NaAsO2-induced cardiotoxicity, and the mechanism may involve its potent antioxidant capacity.

[Bacteriological study on adult chronic sinusitis operated after endoscopic sinus surgery].

OBJECTIVE: To explore the bacteria isolated from middle nasal meatus, maxillary sinus, ethmoid sinus and postoperative cavity of patients with chronic rhinosinusitis and their characteristics of antibiotic resistance. METHODS: Eighty-seven patients with chronic rhinosinusitis were operated on by ESS to obtain the pus specimen for bacterial culture and antibiotic susceptibility test, before and 1 month, 3 months and 6 months after operation. RESULTS: Totally 645 strains (26 species) of bacteria were detected in 464 specimens [total positive rate was 78.9% (366/464)], in which aerobic bacteria was 95.3% (615/645). Gram negative bacteria and gram positive bacteria were 51.2% (330/645) and 48.8% (315/645), respectively. There was supernumerary tendency in detectable rate of gram negative bacteria isolated from postoperative groups. The main pathogens of postoperative patients were gram negative bacteria, with Enterobacter aerogenes, Pseudomonas aeruginosa and Hemophilus influenza occupying the first 3 places. The detectable rate of multiple drug resistance bacteria in postoperative group was much higher than preoperative groups, in which gram negative bacteria was the most, especially for Pseudomonas aeruginosa. There was significant difference in beta-lactamase detectable rate of the bacteria isolated from the delayed recovery group and the preoperative group (chi2 = 4.85, P < 0.05), Enterobacteriaceae occupied the first place among the beta-lactamase detectable bacteria isolated from the delayed recovery group. There was no significant difference in detectable rate of kinds of bacteria isolated from recovery group and control group. CONCLUSIONS: The main pathogens of patients with chronic rhinosinusitis are multiple drug resistance gram negative bacteria after operation, in which Pseudomonas aeruginosa occupies the first place. Gram negative bacteria are becoming the main opportunity pathogenic bacteria, which shows antibiotic resistance. microbial population of postoperative cavity from recovery group are becoming balanced.