Affinity-Guided Isolation and Identification of Procyanidin B2 from Mangosteen (Garcinia mangostana L.) Rinds and its In Vitro LPS Binding and Neutralization Activities.

Garcinia mangostana L. (mangosteen) is a tropical fruit that has been used for medicinal purposes in Southeast Asia for centuries. With an interest in its applications to treat infection, we sought to investigate the bioactive constituents of mangosteen and identified the phenolic compound procyanidin B2 from the mangosteen pericarp by examining lipopolysaccharide (LPS) binding capacity. The LPS binding and neutralization activities of procyanidin B2 were determined by a combination of biophysical and in silico techniques. The affinity of procyanidin B2 to LPS was 1.61 × 10-5 M. Procyanidin B2 significantly neutralized LPS and selectively inhibited the LPS-induced release of tumor necrosis factor (TNF)-α from RAW264.7 cells in a dose-dependent manner. Binding thermodynamics revealed favorable hydrogen bonding and hydrophobic interactions between procyanidin B2 and LPS. Molecular simulations suggested that hydrogen bonding and hydrophobic interactions were involved in the binding process. These findings have, for the first time, shed light on the anti-inflammatory properties of procyanidin B2 through LPS binding and neutralization and provided a promising lead for the development of antiendotoxin agents.

Effectiveness and mechanism study of glutamine on alleviating hypermetabolism in burned rats.

OBJECTIVES: This study aimed to explore the effects of glutamine on hypermetabolic reactions in burned rats and its underlying mechanism. METHODS: Fifty-five Sprague-Dawley rats were randomly divided into three groups, namely, the control (C), burned (B), and burned + glutamine (B + G) groups. Rats in the glutamine treatment group were supplemented with 1 g glutamine per kg body weight. Changes in body weight and resting energy expenditure in all groups were observed daily. Blood glucose and glucose tolerance level were measured on days 1, 3, 7, 10 and 14 after burn injury. On days 7 and 14 after injury, the rats were sacrificed, and the weight and protein content of the skeletal muscle were measured. Moreover, the level of glutamine, inflammatory mediator, nicotinamide adenine dinucleotide phosphate (NADPH), glutathione, and the activity of glutamine metabolic enzymes were measured. RESULTS: The hypermetabolic reaction after burn injury was significantly inhibited by glutamine administration, and the range of variations in the resting energy expenditure and body weight indicators was narrowed remarkably (P < 0.05 or 0.01), whereas the weight and protein content of the skeletal muscle returned to normal (P < 0.05 or 0.01). Glutamine could increase glutaminase activity in various tissues, promote the utilization of glutamine, and appropriately reduce the degree of organ damage and inflammatory response (P < 0.05 or 0.01). Furthermore, glutamine could promote the synthesis of the reducing substances NADPH and glutathione (P < 0.05 or 0.01). CONCLUSIONS: Glutamine administration effectively reduces hypermetabolic reactions by promoting NADPH synthesis, inhibiting oxidative stress, and improving glutamine utilization after burn injury.

Sonographic diagnosis of colorectal polyps in children: Diagnostic accuracy and multi-factor combination evaluation.

This study was established to evaluate the diagnostic value of ultrasonography in screening colorectal polyps in children and to discuss the necessity of colonic preparation before an ultrasonic examination.In this study, 288 children with colorectal polyps managed at our hospital between January 2007 and December 2016 were retrospectively reviewed. All patients were examined before and after basic colon preparation. The colorectal polyps were confirmed by colonoscopy/laparotomy and histopathology. Among all 288 patients, solitary polyps were identified in 278 patients (96.52%), and multiple polyps were identified in 10 patients (43 polyps) (3.48%) by colonoscopy/laparotomy and histopathology.By ultrasonic examination, 264 cases (264/278) were detected as solitary polyp and 9 cases (9/10) as multiple polyps (31 polyps). In 278 solitary polyps, 180 (64.74%) were detected by ultrasonic examination without a colon preparation. Following glycerine enema (10-20 mL) treatment, 264 (94.96%) cases were detected by ultrasonic examination. The sensitivity and specificity of ultrasonography with glycerine enema for the detection of colorectal polyps were 94.96% and 100%, respectively. Colon preparation significantly increased the proportion of polyps identified by ultrasonography (P < .0001), as well as the diagnostic rate of polyps in rectum, sigmoid colon and descending colon (P < .05).Ultrasonography can be the primary diagnostic method for screening colorectal polyps in children on the strength of its safety, validity, and accuracy. Basic colon preparation with glycerine enema is recommended for children, which enable the detection of intraluminal lesions before ultrasonic examination.

Endolysin LysEF-P10 shows potential as an alternative treatment strategy for multidrug-resistant Enterococcus faecalis infections.

Phage-derived lysins can hydrolyse bacterial cell walls and show great potential for combating Gram-positive pathogens. In this study, the potential of LysEF-P10, a new lysin derived from a isolated Enterococcus faecalis phage EF-P10, as an alternative treatment for multidrug-resistant E. faecalis infections, was studied. LysEF-P10 shares only 61% amino acid identity with its closest homologues. Four proteins were expressed: LysEF-P10, the cysteine, histidine-dependent amidohydrolase/peptidase (CHAP) domain (LysEF-P10C), the putative binding domain (LysEF-P10B), and a fusion recombination protein (LysEF-P10B-green fluorescent protein). Only LysEF-P10 showed highly efficient, broad-spectrum bactericidal activity against E. faecalis. Several key functional residues, including the Cys-His-Asn triplet and the calcium-binding site, were confirmed using 3D structure prediction, BLAST and mutation analys. We also found that calcium can switch LysEF-P10 between its active and inactive states and that LysEF-P10B is responsible for binding E. faecalis cells. A single administration of LysEF-P10 (5 µg) was sufficient to protect mice against lethal vancomycin-resistant Enterococcus faecalis (VREF) infection, and LysEF-P10-specific antibody did not affect its bactericidal activity or treatment effect. Moreover, LysEF-P10 reduced the number of Enterococcus colonies and alleviated the gut microbiota imbalance caused by VREF. These results indicate that LysEF-P10 might be an alternative treatment for multidrug-resistant E. faecalis infections.

A method for generation phage cocktail with great therapeutic potential.

BACKGROUND: Bacteriophage could be an alternative to conventional antibiotic therapy against multidrug-resistant bacteria. However, the emergence of resistant variants after phage treatment limited its therapeutic application. METHODOLOGY/PRINCIPAL FINDINGS: In this study, an approach, named "Step-by-Step" (SBS), has been established. This method takes advantage of the occurrence of phage-resistant bacteria variants and ensures that phages lytic for wild-type strain and its phage-resistant variants are selected. A phage cocktail lytic for Klebsiella pneumoniae was established by the SBS method. This phage cocktail consisted of three phages (GH-K1, GH-K2 and GH-K3) which have different but overlapping host strains. Several phage-resistant variants of Klebsiella pneumoniae were isolated after different phages treatments. The virulence of these variants was much weaker [minimal lethal doses (MLD)>1.3×10(9) cfu/mouse] than that of wild-type K7 countpart (MLD = 2.5×10(3) cfu/mouse). Compared with any single phage, the phage cocktail significantly reduced the mutation frequency of Klebsiella pneumoniae and effectively rescued Klebsiella pneumoniae bacteremia in a murine K7 strain challenge model. The minimal protective dose (MPD) of the phage cocktail which was sufficient to protect bacteremic mice from lethal K7 infection was only 3.0×10(4) pfu, significantly smaller (p<0.01) than that of single monophage. Moreover, a delayed administration of this phage cocktail was still effective in protection against K7 challenge. CONCLUSIONS/SIGNIFICANCE: Our data showed that the phage cocktail was more effective in reducing bacterial mutation frequency and in the rescue of murine bacteremia than monophage suggesting that phage cocktail established by SBS method has great therapeutic potential for multidrug-resistant bacteria infection.

Effects of acupuncture on the intrastriatal hemorrhage-induced caspase3 expression and newly cell birth in rats.

BACKGROUND: Intracerebral hemorrhage is one of the most devastating types of stroke. Caspases are essential players in apoptotic cell death both as initiators and executioners. The v-Fos FBJ murine osteosarcoma viral oncogene homolog (Fos, c-Fos) is an immediate early gene, and Fos expression is sometimes used as a marker for stimuli-induced changes in the metabolic activity of neurons. The expressions of caspase3 and Fos are enhanced with neuroregeneration and with neuronal cell death, respectively. Cells proliferation the dentate gyrus of adult rodents is enhanced by certain pathologic events as seizures and ischemic insult, and such up-regulation of cell proliferation occurring during pathologic situations is thought to be a compensatory response to lesion-induced cell death in the brain. In the present study, we investigated the effects of acupuncture on the intrastriatal hemorrhage-induced caspase3 expression in the striatum and on the Fos expression and cell proliferation in the dentate gyrus of rats. METHODS: For this study, immunohistochemistry for caspase3, Fos and 5-bromo-2'-deoxyuridine (BrdU) was performed. RESULTS: Caspase3 expression in the striatum was increased by intrastriatal hemorrhage. Fos expression and cell proliferation in the dentate gyrus of rats with intracerebral hemorrhage were also increased. Acupunctural treatment, especially at the ST36 acupoint, suppressed the intracerebral hemorrhage-induced caspase3 expression in the stratum, and it also inhibited expression of Fos and cell proliferation in the dentate gyrus. CONCLUSION: In the present study, we have shown that acupuncture treatment has a neuroprotective effect on intrastrstriatal hemorrhage-induced neuronal cell death, and this suggests that acupuncture can aid in the recovery of the central nervous system following stroke.