Adsorption activity of coconut (Cocos nucifera L.) cake dietary fibers: effect of acidic treatment,cellulase hydrolysis,particle size and pH

The effects of acidic treatment, cellulase hydrolysis, particle size distribution and pH on the adsorption capacity of defatted coconut cake dietary fibers (DCCDF) were studied. The results demonstrated that cellulase hydrolysis could significantly improve the soluble dietary fiber content, water holding ability and adsorption ability of DCCDF on cholesterol, bile and nitrite ions. Acidic treatment enhanced the oil holding capacity and adsorption ability in cholesterol and nitrite ions. Moreover, the adsorption ability of DFs in cholesterol, nitrite and bile all increased with reduced particle size (250 to 167 μm), and DCCDF demonstrated a higher adsorption capacity at pH 2.0 than at pH 7.0. The change in adsorption capacity of DCCDF might be suitable for application in the food industry as a low-calorie and cholesterol lowering functional ingredient.

This paper provides valuable information on the effects of cellulase hydrolysis, acidic treatment, particle size distribution and pH on the adsorption activity of coconut cake dietary fibers.     

医用高等数学的教育改革

在现代社会,随着医学科学数量化研究的不断深入,医学技术的迅猛发展,其中量化分析对数学的要求日益提高。作为医学专业基础学科,高等数学的课程改革有利于推动医学知识体系的完善,有利于现代化医学研究方法的形成,有利于学生量化分析能力的提高。通过对医用高等数学课程改革必要性的分析,提出了医用高等数学教育改革的措施,并对教师提出更深层次的要求。     

Anti-viral effects of urosolic acid on guinea pig cytomegalovirus in vitro

This study examined the anti-viral effect of ursolic acid on guinea pig cytomegalovirus (GPCMV) and explored the steps of viral replication targeted by ursolic acid. Cytopathic effect assay and MTT method were employed to determine the 50% cellular cytotoxicity (CC50), 50% effective concentration (EC50) and therapeutic index (TI) with GPCMV. To investigate the specific anti-viral effect of ursolic acid at different temperatures and time points, two other medicines, ganciclovir and Jinyebaidu (JYBD), serving as controls, were studied for comparison. Our results showed that the CC50 of ganciclovir, JYBD and ursolic acid were 333.8, 3015.6, 86.7 μg/mL, respectively; EC50 of ganciclovir, JYBD and ursolic acid was 48.1, 325.5 and 6.8 μg/mL, respectively; TI of ganciclovir, JYBD and ursolic acid was 7, 9, 13, respectively. Similar with ganciclovir, ursolic acid could inhibit the viral synthesis, but did not affect the viral adsorption onto and penetration into cells. We are led to conclude that the anti-cytomegalovirus effect of ursolic acid is significantly stronger than ganciclovir or JYBD, and the cytotoxic effect of ursolic acid lies in its ability to inhibit viral synthesis.     

Development and comparative evaluation of real-time PCR and real-time RPA assays for detection of tilapia lake virus

Tilapia lake virus (TiLV) is a newly emerged pathogen responsible for high mortality and economic losses in the global tilapia industry. Early and accurate diagnosis is an important priority for TiLV disease control. In order to evaluate the methodology in the molecular diagnosis of TiLV, we compared newly developed quantitative real-time PCR (qPCR) and real-time recombinase polymerase amplification (real-time RPA) assays regarding their sensitivities, specificities and detection effect on clinical samples. Real-time RPA amplified the target pathogen in less than 30 min at 39 °C with a detection limit of 620 copies, while qPCR required about 60 min with a detection limit of 62 copies. Both assays were specific for TiLV and there were no cross-reactions observed with other common fish pathogens. The assays were validated using 35 tissue samples from clinically infected and 60 from artificially infected animals. The sensitivities for the real-time RPA and qPCR assays were 93.33 and 100%, respectively, and the specificity was 100% for both. Both methods have their advantages and can play their roles in different situations. The qPCR is more suitable for quantitative analysis and accurate detection of TiLV in a diagnostic laboratory, whereas real-time RPA is more suitable for the diagnosis of clinical diseases and preliminary screening for TiLV infection in poorly equipped laboratories as well as in fish farms.     

蛇床子化学成分及其对UMR106细胞增殖作用的影响

目的对蛇床子(蛇床Cnidium monnieri的干燥成熟果实)化学成分进行研究,并探讨所得化合物对类成骨细胞UMR106增殖的影响。方法采用多种色谱柱技术进行分离纯化,通过波谱分析鉴定化合物结构。对所分离得到的化合物进行类成骨细胞UMR106增殖活性的测试。结果从蛇床子75%乙醇提取物中分离得到了9个化合物,分别鉴定为5,7-二羟基-6,8-二甲氧基-2-甲基色原酮(1)、5-羟基-2-羟甲基色原酮(2)、(+)-marmesin(3)、佛手酚(4)、异佛手柑内酯(5)、7-羟基-8-异戊烯二醇基香豆素(6)、murraol(7)、松柏醛(8)、间-羟基苯甲酸(9)。样品溶液浓度为1×10-10 mol/L,化合物1、3、7对类成骨细胞UMR106的增殖促进率分别是31.55%、32.39%和30.87%。结论化合物1~6为首次从蛇床属植物中分离得到。化合物1、3、7能促进UMR106细胞的增殖。     

ACE-inhibitory and antioxidant peptides from coconut cake albumin hydrolysates: purification,identification and synthesis

Coconut cake albumin was hydrolysed by sequential digestion with alcalase, flavourzyme, pepsin and trypsin to purify bioactive peptides with ACE-inhibitory and antioxidant activities. Following fractionation with sequential ultrafiltration, Sephadex gel chromatography and RP-HPLC, three novel peptides KAQYPYV, KIIIYN and KILIYG were identified. KAQYPYV, KIIIYN and KILIYG provided an IC₅₀ value of 37.06 μM, 58.72 μM and 53.31 μM on ACE-inhibitory activity, respectively. For hydroxyl radical scavenging activity, KAQYPYV, KIIIYN and KILIYG demonstrated an IC₅₀ value of 70.84 μM, 77.62 μM and 95.23 μM, respectively. All the three peptides exhibited a mixed modality of noncompetitive and uncompetitive inhibition on ACE and KAQYPYV showed good stability against gastrointestinal enzymes digestion. Moreover, these peptides could effectively lower intracellular endothelin-1 content without significant cytotoxicity, and protected vascular endothelial cells from reactive oxygen species mediated damage. Furthermore, KAQYPYV, KIIIYN and KILIYG also demonstrated high ion chelating ability (62.13% ± 4.21%, 64.66% ± 5.51% and 69.82% ± 7.24% at 0.1 mg mL⁻¹, respectively) and considerable superoxide radical scavenging activity (39.30% ± 2.72%, 46.79% ± 1.70% and 51.16% ± 3.23% at 1.0 mg mL⁻¹, respectively). These results indicate that coconut cake albumin is a potential source of bioactive peptides possessing ACE-inhibitory and antioxidant activities.

Three ACE-inhibitory and antioxidant peptides were identified from enzymatic hydrolysates of coconut cake albumin in the current study.     

Weight reduction and pharmacologic treatment in obese hypertensives

This study was conducted to evaluate the mechanisms of weight loss-induced blood pressure (BP) reduction focusing, in particular, on the contributions of sympathetic nervous system activity, fasting plasma insulin, and leptin to BP levels, and to delineate the additional influence of antihypertensive drug therapy. Each of five groups of obese hypertensives were treated with the long-acting calcium channel blocker (CCB) amlodipine, the angiotensin converting enzyme (ACE) inhibitor enalapril with or without a weight reduction program, or a weight reduction program alone. The goal BP was less than 140/90 mm Hg for the pharmacologic treatment groups. The weight reduction program groups with or without pharmacologic treatment were divided into two groups; weight loss groups who succeeded in weight reduction (≥10%) and nonweight loss groups who failed in weight reduction (<10%) in the first 6 months.The final dose of CCB and ACE inhibitor were less in the combined pharmacologic and weight loss groups than in the pharmacologic treatment alone groups or in the pharmacologic and nonweight loss groups. In the weight reduction groups regardless of pharmacologic treatment, the percent reductions from baseline in plasma insulin, leptin, and norepinephrine (NE) were greater in the weight loss groups (≥10%) than in the nonweight loss groups (<10%). The reductions in plasma NE, insulin, and leptin were significantly greater and earlier in combined pharmacologic and weight loss groups than in the pharmacologic treatment alone groups. In ACE inhibitor groups, the reductions in plasma NE, in insulin, and especially in leptin were greater than the other groups. In the CCB alone group, reductions in insulin and leptin occurred, but there was no change in plasma NE. Reductions in insulin and leptin in CCB groups were less and occurred later than in the ACE inhibitor groups or the weight reduction alone group.These results show that weight loss associated with favorable metabolic improvements and these improvements are amplified when combined with pharmacologic treatment. Therefore, weight loss should be regarded as an essential component of any treatment program for obesity-related hypertension. A novel finding from this study is that ACE inhibition had a striking effect to lower plasma leptin. Suppression of sympathetic activity, insulinemia, and leptinemia appeared to play a role in the BP reduction accompanying weight loss.