Antioxidant properties of flavonoid derivatives and their hepatoprotective effects on CCl4 induced acute liver injury in mice

Excessive accumulation of free radicals in the body can cause liver damage, aging, cancer, stroke, and myocardial infarction. Anastatin B, a skeletal flavonoid, was reported to have antioxidant and hepatoprotective effects. Anastatin B derivatives, compound 1 and 2, were synthesized by our group previously. In this study, their antioxidant activity and hepatoprotective mechanism were studied using chemical evaluation methods, a cellular model of hydrogen peroxide (H₂O₂)-induced oxidative damage, and a mouse model of carbon tetrachloride (CCl₄)-induced liver injury. Results from the chemical evaluation suggested that both compounds had good antioxidant power and radical scavenging ability in vitro. MTT assay showed that both compounds had cytoprotective activity in H₂O₂-treated PC12 cells. Moreover, their hepatoprotective activities evaluated using a mouse model of CCl₄-induced liver injury that compared with the model group, pretreatment with compound 1 and 2 significantly decreased alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH), and malondialdehyde (MDA) levels; reduced the liver tissue damage; and increased glutathione content. However, compound 2 was a more effective hepatoprotectant than compound 1 was. Finally, the amount of TNF-α and cytochrome P450 2E1 (CYP2E1) were significantly downregulated in compound 1 and 2 pretreatment groups. Collectively, our findings demonstrate that both compounds have potential antioxidant activity and hepatoprotective effect in vitro and in vivo. Further chemo-biological study and investigation of the compounds'' enzymatic targets are ongoing.

Excessive accumulation of free radicals in the body can cause liver damage, aging, cancer, stroke, and myocardial infarction.     

Analysis of oxidation degree of graphite oxide and chemical structure of corresponding reduced graphite oxide by selecting different-sized original graphite

The thermal exfoliation and reduction of graphite oxide (GO) is the most commonly used strategy for large-scale preparation of graphene, and the oxidation degree of GO would influence the chemical structure of prepared graphene, thereby affecting its final physical and chemical properties. In addition to serving as the precursor for synthesizing graphene, GO also possesses great potential for various important applications owing to its abundant oxygen-containing groups and hybrid electronic structure. Therefore, systematically studying the influencing factors on the oxidation degree of GO and clarifying the effect of oxidation degree on the corresponding graphene is particularly important. Herein, we have studied the effect of the lateral size of the original graphite on the oxidation degree of GO in order to control the oxidation degree of GO. GOs with different degrees of oxidation were synthesized using a modified Hummers method. The results of X-ray diffraction (XRD), X-ray photoelectron spectra (XPS) and Raman spectroscopy revealed that decreased lateral size of the original graphite would lead to increased oxidation degree of GO. Furthermore, the interlayer spacing of the GO samples achieved 0.9–1.0 nm, which indicated that the modified Hummers method could make well oxidized graphite. The corresponding reduced graphite oxide (rGO) was also prepared by low-temperature exfoliation of GO at 140 °C under ambient atmosphere. It was found that a larger lateral size of GO resulted in rGO with fewer oxygen-containing functional groups, but a smaller lateral size of graphite possessed a higher exfoliation degree with a larger specific surface area. More importantly, the relationship between binding energy (E_B) of photoelectron of C atom in oxygen-containing groups and the number of oxygen-containing groups in GO and rGO samples was analyzed theoretically.

The thermal reduction of GO is the most commonly used strategy for preparation of rGO, and the oxidation degree of GO would influence the chemical structure of prepared rGO, thereby affecting its physical and chemical properties.     

ALEX1 may be a novel biomarker for human cervical squamous cell carcinoma

The armadillo repeat proteins were first found in armadillo gene of Drosophila. Since then a number of proteins containing armadillo repeats have been noticed and studied. These proteins that consist of 6 to 13 armadillo repeat domains are classified as family of armadillo repeat proteins. Recently, several studies indicated that armadillo repeat family of proteins play an important role in the tumorigenesis and maintenance of tissue integrity. ALEX1 (Arm protein lost in epithelial cancers, on chromosome X), contains two armadillo repeats domains, is expressed different in normal and carcinomas tissues. Several studies have found that ALEX1 protein lost in tumors that originated in epithelial tissues. We evaluated the ALEX1 protein expression in 53 cervical cancers and in 53 non-cancerous cervical tissues from patients and adjacent non-cancerous tissues using immunohistochemistry Results: ALEX1 protein expression is significantly increased in 53 cervical cancers tissues compared with non-cancerous tissues. We found, for the first time, that ALEX1 protein expression in cervical cancers tissues is higher than non-cancerous tissues. It is suggested that the ALEX1 protein is associated with tumorigenesis in cervical cancer and we speculate that the ALEX1 may plays a role as an oncogene in cervical cancer. Moreover, ALEX1 may serve as a novel potential diagnostic biomarker in identifying cervical cancer.     

糖皮质激素治疗对急性呼吸窘迫综合征患者预后的影响

目的：探讨早期应用糖皮质激素（GC）治疗对急性呼吸窘迫综合征（ARDS）患者预后的影响。方法回顾性分析成都军区总医院2008年1月至2011年12月收治的所有ARDS病例的临床资料,选择符合2012年柏林ARDS诊断标准的成人患者,根据是否采用过GC治疗将患者分为GC组与非GC组。GC组患者均在ARDS发生48 h内开始静脉使用低剂量GC（＜5 mg·kg-1·d-1,均换算为氢化可的松的剂量）治疗,激素种类为甲泼尼松龙、地塞米松,疗程为7～21 d;而非GC组为ARDS发生后未使用GC治疗。比较两组患者机械通气时间、重症加强治疗病房（ICU）住院时间、总住院时间、医疗费用和28 d生存率的差异。结果共纳入ARDS患者117例,其中GC组56例（占47.86%）,非GC组61例（占52.14%）。与非GC组比较,GC组机械通气时间明显缩短〔d：0（0,2.50）比2.00（0,2.50）,Z＝2.015,P＝0.044〕,28 d生存率明显升高〔71.43%（40/56）比50.82%（31/61）,χ2＝5.198,P＝0.023〕,ICU住院时间〔d：7.50（2.00,11.00）比4.00（1.00,9.00）,Z＝1.879, P＝0.060〕和总住院时间〔d：16.00（10.00,27.75）比15.00（7.00,28.00）,Z＝0.592,P＝0.552〕差异无统计学意义,但非GC组患者的医疗费用显著低于GC组〔万元：3.15（1.51,5.78）比4.39（1.66,10.88）,Z＝2.204,P＝0.028〕。结论早期使用GC治疗ADRS患者可改善预后,特别是28 d生存率。     

Effect of iron ion diffusion on the corrosion behavior of carbon steels in soil environment

The corrosion behavior of metal materials in soil environments has been intensively studied recently. Even so, the detailed corrosion mechanisms remain elusive, especially regarding the role of metal ions. In this study, we investigated the effect of ion diffusion on the corrosion processes of carbon steel via scanning electron microscopy (SEM), in situ laser Raman spectroscopy and scanning Kelvin probe (SKP). It was found that the Fe³⁺ diffusion was a key factor to the corrosion rate, as well as the formation of corrosion products. Typically, the corrosion products suppressed the diffusion of ions to the surface of carbon steels, and thus the cation diffusion coefficient played a significant role in formation processes of corrosion products, which furthermore affected the corrosion processes of the carbon steels.

The corrosion behavior of metal materials in soil environments has been intensively studied recently.     

Hansforesters A–M,polyesters from the sponge-associated fungus Hansfordia sinuosae with antibacterial activities

Bioassay-guided fractionation and chromatographic separation of a sponge-derived fungus Hansfordia sinuosae, resulted in the isolation of thirteen new polyesters namely hansforesters A–M (1–13), along with five known analogues involving ascotrichalactone A, ascotrichester B, 15G256π, 6R-hydroxymellein, and (−)orthosporin. The structures of the new compounds were determined through extensive spectroscopic analysis, in addition to the chemical conversion for the configurational assignment. The polyesters incorporating the motifs of orsellinic acid, 2,4-dihydroxy-6-acetonylbenzoic acid, and orcinotriol were found from nature for the first time. Hansforester A (1) and ascotrichalactone A exhibited potent inhibition against a panel of bacterial strains, including the agricultural pathogenic bacteria, Pseudomonas lachrymans, Agrobacterium tumefaciens, Xanthomonas vesicatoria, and Ralstonia solanacearum, with the MIC values of 15.6 μM, and the human infected bacterium Staphylococcus aureus with the MIC values of 3.9 μM. These findings suggested that hansforester A and ascotrichalactone A are the potential leads to be developed as the antibacterial agents for the treatment of agriculture bacterial pathogens.

Bioassay-guided separation of a sponge-derived fungus Hansfordia sinuosae afforded thirteen new polyesters namely hansforesters A–M. Hansforester A and ascotrichalactone A exhibited potent inhibition against a panel of bacterial strains.