黑木耳黑色素对急性肝损伤的改善作用

黑色素是一种广泛存在于动物、植物、细菌及真菌中的生物色素,具有多种生物功能及良好的生物活性。黑木耳以“黑”出名,其富含的黑色素具有广阔开发应用价值。本研究旨在评价黑木耳黑色素对急性肝损伤的改善作用。首先应用傅里叶红外光谱初步对提取的黑木耳黑色素进行鉴定,再通过DPPH自由基及羟基自由基清除实验证实提取的黑木耳黑色素体外抗氧化能力,并进一步以四氯化碳致小鼠急性肝损伤为模型,通过检测血清酶指标、肝功指标的变化及病理切片情况,来评价黑木耳黑色素体内抗氧化及保肝效果。结果表明,提取的黑木耳黑色素具有黑色素特征的官能团结构和良好的体外抗氧化能力,对DPPH自由基和羟基（OH）自由基清除的EC₅₀分别为0.0887mg/mL、2.2030mg/mL;动物体内实验中,与模型组对比,给药组（黑木耳黑色素）的小鼠血清中ALT、AST含量显著降低（P<0.01）,肝脏中MDA含量显著降低（P<0.01）和SOD活性显著升高（P<0.01）,并且肝细胞病理状态明显改善。本文报道了黑木耳黑色素在体内能有效改善四氯化碳诱导的小鼠肝损伤,为黑木耳的功能产品开发提供了新思路和研究基础。     

苜蓿二磷酸核酮糖(RuBP)羧化酶体内活化作用的调节

苜蓿RuBP羧化酶的初活性和活化作用在不饱和光强下与光合速率一样随光强增加而增加。缺硫培养苜蓿叶片的光合速率和RuBP羧化酶的含量、初活性及总活性均比对照有不同程度的降低,其中酶的初活性与光合速率两者减少的趋势比较接近,说明RuBP羧化酶的初活性可能在光合CO_2固定作用中具有决定作用。然而,缺硫植株中酶的活化作用比对照明显增高。酶的活化作用与叶片中的叶绿素,6-PG,NADPH及ATP相对酶含量的比值成正比,与体内的酶量成反比。     

Electro-Acupuncture Pretreatment Ameliorates Anesthesia and Surgery-Induced Cognitive Dysfunction Via Inhibiting Mitochondrial Injury and nEuroapoptosis in Aged Rats

Neurochemical Research - Postoperative cognitive dysfunction (POCD) remains one of the most common complications following anesthesia and surgery (AS) in the elderly population. Calcium-mediated...     

Cytotoxic,clonal fidelity,and antioxidant evaluation of in vitro propagated Vitex negundo var. cannabifolia

Plant Cell, Tissue and Organ Culture (PCTOC) - Vitex negundo L. var. cannabifolia (Sieb. et Zucc.) Hand.-Mazz. is an important medicinal plant rich in bioactive compounds. In vitro tissue culture...     

Differential effects of paraoxonase 1 (PON1) polymorphisms on cancer risk: evidence from 25 published studies

Paraoxonase is an HDL-associated enzyme that plays a preventive role against oxidative stress, which is thought to contribute to cancer development. PON1 activity varies widely among individuals, which is in part related to two common nonsynonymous polymorphisms in the PON1 gene (Q192R and L55M). The polymorphisms in PON1 have been implicated in cancer risk. However, results from the studies to date have been conflicting. To clarify the association, a meta-analysis was performed for 7,073 cases and 9,520 controls from 25 published case–control studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. Significant associations between PON1-L55M but not Q192R polymorphism and total cancer were observed from all the comparisons. In stratified analyses, PON1-55M allele was a risk factor for breast cancer. Similarly, increased risk was observed for prostate cancer (OR = 1.18, 95% CI: 1.01–1.36, P _{heterogeneity} = 0.260) and Caucasian population (OR = 1.18, 95% CI: 1.02–1.38, P _{heterogeneity} = 0.1) of the LM genotype, compared with the LL genotype. For PON1-Q192R polymorphism, PON1-192R allele was a decreased risk factor for cancer in the Asian group (RR vs QQ: OR = 0.61, 95% CI: 0.38–0.98, P _{heterogeneity} = 0.268; QR vs QQ: OR = 0.71, 95% CI: 0.52–0.96, P _{heterogeneity} = 0.130; RR + QR vs QQ: OR = 0.71, 95% CI: 0.53–0.95, P _{heterogeneity} = 0.135). Although some modest bias could not be eliminated, this meta-analysis suggests that the PON1-55M allele is a risk factor for the development of cancer, in particular for breast cancer. Future studies with larger sample sizes are warranted to further evaluate these associations.     

The role of estrogen receptor-beta, in the early age-related bone gain and later age-related bone loss in female mice

The molecular and cellular mechanism of estrogen action in skeletal tissue remains unclear. The purpose of this study was to understand the role of estrogen receptor-beta, (ERbeta) on cortical and cancellous bone during growth and aging by comparing the bone phenotype of 6- and 13-month-old female mice with or without ERbeta. Groups of 11-14 wild-type (WT) controls and ERbeta knockout (BERKO) female mice were necropsied at 6 and 13 months of age. At both ages, BERKO mice did not differ significantly from WT controls in uterine weight and uterine epithelial thickness, indicating that ERbeta does not regulate the growth of uterine tissue. Femoral length increased significantly by 5.5% at 6 months of age in BERKO mice compared with WT controls. At 6 months of age, peripheral quantitative computerized tomography (pQCT) analysis of the distal femoral metaphysis (DFM) and femoral shafts showed that BERKO mice had significantly higher cortical bone content and periosteal circumference as compared with WT controls at both sites. In contrast to the findings in cortical bone, at 6 months of age, there was no difference between BERKO and WT mice in trabecular density, trabecular bone volume (TBV), or formation and resorption indices at the DFM. In 13-month-old WT mice, TBV (-41%), trabecular density (-27%) and cortical thickness decreased significantly. while marrow cavity and endocortical circumference increased significantly compared with 6-month-old WT mice. These age-related decreases in cancellous and endocortical bone did not occur in BERKO mice. At 13 months of age, BERKO mice had significantly higher total, trabecular and cortical bone, while having significantly lower bone resorption, bone formation and bone turnover in DFM compared with WT mice. These results indicate that deleting ERbeta protected against age-related bone loss in both the cancellous and endocortical compartments by decreasing bone resorption and bone turnover in aged female mice. These data demonstrate that in female mice, ERbeta plays a role in inhibiting periosteal bone formation, longitudinal and radial bone growth during the growth period, while it plays a role in stimulating bone resorption, bone turnover and bone loss on cancellous and endocortical bone surfaces during the aging process.