Inhibition of Xanthine Oxidase Activity by Gnaphalium Affine Extract

Objective To evaluate the inhibitory effect of Gnaphalium affine extracts on xanthine oxidase(XO) activity in vitro and to analyze the mechanism of this effect. Methods In this in vitro study, Kinetic measurements were performed in 4 different inhibitor concentrations and 5 different xanthine concentrations(60, 100, 200, 300, 400 μmol/L). Dixon and Lineweaver-Burk plot analysis were used to determine Ki values and the inhibition mode for the compounds isolated from Gnaphalium affine extract. Results Four potent xanthine oxidase inhibitors were found in 95% ethanolic(v/v) Gnaphalium affine extract. Among them, the f lavone Eupatilin exhibited the strongest inhibitory effect on XO with a inhibition constant(Ki) of 0.37 μmol/L, lower than the Ki of allopurinol(4.56 mol/L), a known synthetic XO inhibitor. Apigenin(Ki of 0.56 μmol/L, a proportion of 0.0053‰ in Gnaphalium affine), luteolin(Ki of 2.63 μmol/L, 0.0032‰ in Gnaphalium affine) and 5-hydroxy-6,7,3',4'-tetramethoxyflavone(Ki of 3.15 μmol/L, 0.0043‰ in Gnaphalium affine) also contributed to the inhibitory effect of Gnaphalium affine extract on XO activity. Conclusions These results suggest that the use of Gnaphalium affine in the treatment of gout could be attributed to its inhibitory effect on XO. This study provides a rational basis for the traditional use of Gnaphalium affine against gout.

Xanthine oxidase inhibitors from Archidendron clypearia(Jack.) I.C. Nielsen: Results from systematic screening of Vietnamese medicinal plants

Objective: To screen Vietnamese medicinal plants for xanthine oxidase(XO) inhibitory activity and to isolate XO inhibitor(s) from the most active plant. Methods: The plants materials were extracted by methanol. The active plant materials were fractionated using different organic solvents, including n-hexane, ethyl acetate, and n-butanol. Bioassay-guided fractionation and column chromatography were used to isolate compounds. The compounds structures were elucidated by analysis of spectroscopic data, including IR, MS, and NMR. Results: Three hundreds and eleven methanol extracts(CME) belonging to 301 Vietnamese herbs were screened for XO inhibitory activity. Among these plants, 57 extracts displayed XO inhibitory activity at 100 μg/m L with inhibition rates of over 50%. The extracts of Archidendron clypearia, Smilax poilanei, Linociera ramiflora and Passiflora foetida exhibited the greatest potency with IC_(50) values below 30 μg/m L. Chemical study performed on the extract of Archidendron clypearia resulted in the isolation of six compounds, including 1-octacosanol, docosenoic acid, daucosterol, methyl gallate, quercitrin and(-)-7-O-galloyltricetiflavan. The compound(-)-7-O-galloyltricetiflavan showed the most potent XO inhibitory activity with an IC_(50) value of 25.5 μmol/L. Conclusions: From this investigation, four Vietnamese medicinal plants were identified to have XO inhibitory effects with IC_(50) values of the methanol extracts below 30 μg/m L. Compound(-)-7-O-galloyltricetiflavan was identified as an XO inhibitor from Archidendron clypearia with IC_(50) value of 25.5 μmol/L.

Identifi cation of egg protein-derived peptides as xanthine oxidase inhibitors:virtual hydrolysis,molecular docking,and in vitro activity evaluation

The purpose of this study was to screen the xanthine oxidase(XO)inhibitory peptides from egg white proteins through virtual hydrolysis,in vitro activity validation,and molecular docking.The results demonstrated that tripeptide EEK from ovalbumin exhibited potent XO inhibitory activity with an IC50 value of 141μmol/L.The molecular docking results showed that tripeptide EEK bound with the active center of XO via 3 carbon hydrogen bond interactions,2 salt bridges,5 conventional hydrogen bond interactions,and 4 attractive charge interactions.The residues Glu802,Phe1009,and Arg880 may play key roles in the XO catalytic reaction.Especially,the key intermolecular forces of inhibiting XO activity may be special type of hydrogen bonds including carbon hydrogen bond interactions and attraction charge interactions.The novel tripeptide EEK is potential candidates for controlling hyperuricemia.

葛根异黄酮抑制XOD和GLUT9分别发挥减少尿酸生成、促进尿酸排泄双重途径的机制

目的:分析葛根异黄酮抑制XOD和GLUT9分别发挥减少尿酸生成、促进尿酸排泄的可能机制。方法:2021年8月~2022年4月,采用随机数字表法将40只SPF级雄性昆明小鼠分为健康组(1次d频率250 mg/kg剂量灌胃羧甲基纤维素钠)、模型组(HUA小鼠1次d频率250 mg/kg剂量灌胃羧甲基纤维素钠)和低(HUA小鼠1次d频率125 mg/kg剂量灌胃葛根异黄酮)、中(HUA小鼠1次d频率250 mg/kg剂量灌胃葛根异黄酮)、高(HUA小鼠1次d频率500 mg/kg剂量灌胃葛根异黄酮)剂量组,每组各8只。比较各组干预前和干预后(30 d)血清和尿液中尿酸(SUA)、尿素氮(BUN)、肌酐(SCr)含量的统计学差异,比较各组干预后(30 d)肾脏组织中黄嘌呤氧化酶(XOD)和人葡萄糖转运蛋白9(GLUT9)、环氧化酶-2(COX-2)、肿瘤坏死因子(TNF-ɑ)、白细胞介素-1(IL-1β)含量的统计学差异。结果:干预后比较,模型组肾脏炎症因子(COX-2、TNF-ɑ、IL-1β);血液和尿液3项指标(SUA、BUN、SCr);XOD、GLUT9含量均高于健康组(P<0.05);低、中、高剂量组肾脏炎症因子(COX-2、TNF-ɑ、IL-1β);血液和尿液3项指标(SUA、BUN、SCr);XOD、GLUT9含量均低于模型组,且有低>中>高剂量组,两两分组的比较均有统计学意义(P<0.05)。干预后相比干预前,血液或尿液3项指标(COX-2、TNF-ɑ、IL-1β)含量均有下降,组内比较的差异均有统计学意义(P<0.05)。结论:葛根异黄酮能治疗HUA小鼠能通过抑制XOD、GLUT9表达,继而发挥减少尿酸生成、促进尿酸排泄作用,同时有利于缓解疾病的炎症程度。

Study of Xanthine Oxidase Activity in Sera of Iraqi Children with Nephrotic Syndrome

Introduction: To investigate the relationship of xanthine oxidase activity with nephrotic syndrome disorder in children, and the optimization of the enzyme activity conditions in the disorder. Material and methods: Sera of children with nephrotic syndrome (NS) (60 samples) were obtained from Central Child Teaching Al Karama Hospital (CCTAH), from 2nd Mar. 2013 to 28th Feb. 2014. Sera of the patients were assayed for xanthine oxidase (XO) activity using colorimetric absorbance technique. The obtained results were compared with the enzyme activity of normal children (70 samples) as control. Results and conclusions: The results revealed a significant (P < 0.001) elevation in XO activity in serum of nephrotic syndrome (0.12 ± 0.06 IU/L) compared with that of normal subjects (0.05 ± 0.009 IU/L), showing an elevation of (70%) in XO activity (about 2/3) that of normal group. Factors influencing XO activities were also studied and showed that XO activity is a pH dependent. Significant elevation (P < 0.001) was found in uric acid level in sera of NS patients (497.52 ± 3.21 μmol/L) compared with that in normal group (298.12 ± 1.70 μmol/L). Elevation was found in urea level in sera of NS patient (10.69 ± 7.55 mmol/L) compared with that of normal group (4.57 ± 1.27 mmol/L). It was appeared, there is a role of XO activity in the pathogenesis of endothelial injury during glomerular lesion in NS and that was confirmed by comparing XO activity and other related conditions with the activity of normal volunteers.

A Sensitive Reversed-Phase High-Performance Liquid Chromatography Method for the Quantitative Determination of Milk Xanthine Oxidase Activity

A new reversed-phase high performance liquid chromatography method was developed to quantitate the activity of xanthine oxidase involved in milk fat globule membrane with xanthine as the substrate and the separation of product (uric acid). The increment of uric acid in the reaction system was used to calculate the total activity of XO. The optimized assay conditions, linearity of detection, recovery of uric acid and chromatogram were developed in text, indicating this method is simple, rapid and efficient. It is an alternative potential method for the determination of the activity of XO in milk.

Determination of inhibitory activity of Salvia miltiorrhiza extracts on xanthine oxidase with a paper-based analytical device

A novel paper-based analytical device(PAD)was prepared and applied to determine the xanthine oxidase(XOD)inhibitory activity of Salvia miltiorrhiza extracts(SME).First,polycaprolactone was 3D printed on filter paper and heated to form hydrophobic barriers.Then the modified paper was cut according to the specific design.Necessary reagents including XOD for the colorimetric assay were immobilized on two separate pieces of paper.By simply adding phosphate buffer,the reaction was performed on the double-layer PAD.Quantitative results were obtained by analyzing the color intensity with the specialized device system(consisting of a smartphone,a detection box and sandwich plates).The 3Dprinted detection box was small,with a size of 9.0 cm×7.0 cm×11.5 cm.Color component G performed well in terms of linearity and detection limits and thus was identified as the index.The reaction conditions were optimized using a definitive screening design.Moreover,a 10%glycerol solution was found to be a suitable stabilizer.When the stabilizer was added,the activity of XOD could be maintained for at least 15 days under 4℃ or-20℃ storage conditions.The inhibitory activity of SME was investigated and compared to that of allopurinol.The results obtained with the PAD showed agreement with those obtained with the microplate method.In conclusion,the proposed PAD method is simple,accurate and has a potential for point-of-care testing.It also holds promise for use in rapid quality testing of medicinal herbs,intermediate products,and preparations of traditional Chinese medicines.

Study the effect of kidney stones on serum xanthine oxidase, ecto-5'-nucleotidase activity and E3 SUMO-protein ligase NSE2(NSMCE2) in Malaysian individuals

Objective: To verify possible relations between 5'-nucleotidase, xanthine oxidase to E3 small ubiquitin-like modifier-protein ligase non structural maintenance of chromosomes elements 2 in sera patients with kidney stones and to evaluate the possibility of a new biomarker for the evaluation of kidney damage. Methods: A sixty patients with known kidney stones who appeared the government health clinics in Kuantan–Pahang and fifty apparently healthy were taken as control group. The 5'-nucleotidase,xanthine oxidase and other biochemical parameters were measured by colorimetric tests. The serum NSMCE2 were measured by enzyme linked immunosorbent assay.Results: The mean serum xanthine oxidase [(39.98±19.70) IU/L] and ecto-5'-nucleotidase activity(40.03±9.53 IU/L) were significantly higher than the controls' levels of(18.04 ±6.26) and(16.06 ±4.61) IU/L respectively. There were 85.00% and 83.33%, of patients with kidney stones who had abnormal ecto-5'-nucleotidase activity and uric acid respectively while xanthine oxidase activity was less sensitive 58.33%.Conclusions: The present study suggests that the increase in serum of xanthine oxidase,ecto-5'-nucleotidase activities E3 small ubiquitin-like modifier-protein ligase NSE2 concentration can be used as biomarkers for diagnosis of kidney damage in patients with kidney stone,also in developments of change DNA damage and inflammation disorders in these patients.

Inhibitory Activity on Xanthine Oxidase and Antioxidant Properties of <i>Teucrium polium</i>

The antioxidative activities of subfractions;methanol (CE), chloroform (CHE) and ethyl acetate (EAE) of Teucrium polium extracts (TPE) were investigated. HPLC analysis of the plant revealed the existence of procyanidins B1 and B2, gallic acid, catechin and epicatechin. All the extracts showed inhibitory properties on xanthine oxidase, with IC50 ranging from 0.80 ± 0.07 to 11.76 ± 0.50 μM/quercetin equivalent. In the cellular system, all the extracts showed a protec-tive effect greater than those of quercetin, rutin and gallic acid against t-BHP induced oxidative damages in human erythrocytes. These results were clearly confirmed by a modified thiobarbituric acid-reactive species (TBARS), and β-carotene/linoleic acid assay which demonstrated that CHE possess an inhibition ratio of the linoleic acid oxidation (83.11%) close to that of BHT (96.77%). In addition, the results showed that the extracts possess a potent DPPH radical scavenging activity and gave a reduction power greater than rutin, quercetin, gallic acid and ascorbic acid in FRAP assay. These results show that Teucrium polium extracts have strong antioxidant effects and may have some clinical benefits.

Correlation of docking energies with spectroscopic kinetic assays of potential xanthine oxidase substrates

Here we present a docking model that ranks compounds according to their potential effectiveness as a potential substrate or inhibitor. We utilize xanthine oxidase (XO), a multi-cofactor oxido-reductase which converts hypoxanthine to xanthine and xanthine to uric acid. During the reductive half reaction, electrons flow from the molybdopterin, to each of two Fe/S centers, and finally to FAD. During the oxidative half reaction, electrons are passed from the FAD to O2. Under ideal physiological conditions, this reduction of oxygen generates H2O2 and, under multiple turnover conditions, superoxide in amounts which is regulated by catalase and superoxide dismutase. Utilizing computer modeling predictions of the docking orientations and energies of a group of purine based structures was selected. Correlating computer estimations with steady state kinetic data, a rapid screening process for inhibittor prediction was highlighted. This method allows educated selection of likely inhibitors, thereby decreasing the time and supplies required to complete a traditional kinetic analysis screening. Results demonstrate the functionality and reliability of this method and have proven particularly useful in understanding binding orienttations or poses of each compound.

<i>In Silico</i>and <i>in Vitro</i>Approach for the Understanding of the Xanthine Oxidase Inhibitory Activity of Uruguayan Tannat Grape Pomace and Propolis Poliphenols

The use of food additives with xanthine oxidase (XO) inhibitory activity offers an alternative approach to hyperuricemic and gout disease treatment, and provides an example of antioxidant nutraceutics. The in vitro and in silico XO inhibitory activity of polyphenols from Uruguayan Tannat grape pomaces and propolis extracts was evaluated as well as the scavenging capacity of said compounds. When comparing propolis and grape pomace samples, the in vitro studies demonstrated that polyphenols extracted from propolis are more active as free radical scavengers than those from Tannat grape pomace. Both natural products effectively inhibited XO but the capacity of phenols present in GP is higher than the one present in P. The high content of anthocyanins in GP, absent in P, could account for this observation. In silico assays allowed us to determine relevant ligand-receptor interactions between polyphenols, from a database built with previously reported polyphenols from both natural products, and the active site of XO. The in silico results showed that compound (E)-isoprenylcaffeate from propolis was the best potential XO inhibitor displaying hydrophobic aromatic interaction between the conjugated ring of the caffeate moiety and polar interactions between hydroxyl groups from caffeate with the active site polar residues. Among grape pomaces, the Cyanidin-3-O-(6-(E)-p-coumaroyl)-glucoside was the best XO inhibitor;its moiety oxychromenyl being relevant to the docking stabilization. All these results lead us to propose Uruguayan propolis and Tannat grape pomace extracts as food additives as well as phytopharmaceuticals to decrease the uric acid levels in gout disease and to act against oxidative stress.

Effect of TongFengNing Decoction on Uric Acid Levels and Xanthine Oxidase Activity in Hyperuricemia Rats

Objective To observe the effect of TongFengNing Decoction （TD） on uric acid levels, xanthine oxidase （XOD） activity, and XOD mRNA expression of hyperuricemia （HUA） model rats. Methods： 90 rats were randomly divided into 6 groups （n=15）, and the HUA model in all groups except the blank group was established by administering hypoxanthine （HX） by gavage and injecting potassium oxonate （OAPS） intraperitoneally. Rats in all TD groups and allopurinol group were administered multiple doses of TD and a single dose of allopurinol by gavage twice daily for 21 days, while the blank group and the model group were administered normal saline. On the 7th, 14th, and 21st days of drug intervention, serum uric acid （SUA）, urine uric acid （UUA）, intestinal uric acid （IUA）, as well as XOD activity and mRNA expression in the liver and small intestine were measured in randomly selected 5 rats of each group. Results： On the 14th and 21st days of intervention, all TD dose groups and the allopurinol group showed decreased SUA and IUA levels, increased UUA levels, as well as decreased XOD activity and mRNA expression in the liver and small intestine, compared with the model group （P 〈 0.05）. The low- and high-dose TD group and the allopurinol group showed increased SUA and IUA levels, as well as XOD activity and mRNA expression in the liver and small intestine, and decreased UUA levels, compared with the moderate-dose TD group （P〈0.05）. Upon extending the drug intervention time of each TD dose group, SUA and IUA levels, XOD activity, and XOD mRNA expression in the liver and small intestine decreased and UUA levels increased （P 〈 0.05）. Conclusion： TD reduces SUA levels in HUA model rats, which promotes uric acid excretion and inhibits XOD activity and XOD mRNA expression to reduce uric acid production. The reduction in uric acid level by the intermediate dose of TD was better than that by allopurinol and the low and high doses of TD.

Pueraria isoflavones inhibit XOD and GLUT9 to decrease uric acid production and promote uric acid excretion, respectively

Objective: To analyze the possible mechanism of Pueraria isoflavones inhibiting XOD and GLUT9 to reduce uric acid production and promote uric acid excretion. Methods: August 2021-April 2022, a total of forty SPF male Kunming mice were divided into the healthy group (carboxymethylcellulose sodium at a dose of 250 mg/kg), the model group (HUA mice were given carboxymethylcellulose sodium at a dose of 250 mg/kg), the low group (HUA mice were given pueraria isoflavone at a dose of 125 mg/kg), HUA mice were given pueraria isoflavones at a dose of 250 mg/kg once d frequency)and the high group (HUA mice were given pueraria isoflavones at a dose of 500 mg/kg once d frequency) dosage groups, with 8 mice in each group. The contents of uric acid (SUA), urea nitrogen (BUN) and creatinine (SCr) in serum and urine of each group were compared before and after intervention (30 d). Statistical differences of xanthine oxidase (XOD) and human glucose transporter 9(GLUT9), cy- clooxygenase- 2(COX-2), tumor necrosis factor (TNF-α) and interleukin-1 (IL-1β) contents in renal tissues of each group after intervention (30 d) were compared. Results: After intervention, kidney inflammatory factors (COX-2, TNF-α and IL-1β) in the model group were compared. Blood and urine indexes (SUA, BUN, SCr);The contents of XOD and GLUT9 were higher than those of healthy group(P<0.05). Renal inflammatory cytokines (COX-2, TNF-α and IL-1β) in low, medium and high dose groups;Blood and urine indexes (SUA, BUN, SCr);The contents of XOD and GLUT9 were lower than those of model group, and there were low > medium > high dose groups, the comparison between the two groups had statistical significance(P< 0.05). After intervention, the contents of 3 indicators in blood or urine(COX-2, TNF-α and IL-1β) all decreased compared with before intervention, and the differences in intra-group comparison were statistically significant (P<0.05). Conclusion: Pueraria isoflavones can treat HUA mice by inhibiting the expression of XOD and GLUT9, and then play a role in reducing uric acid pro- duction and promoting uric acid excretion, as well as alleviating the degree of disease inflammation.

不同添加物对鱼糜凝胶品质的影响及其降尿酸潜在作用评价

为开发高品质的功能性鱼糜制品,以白鲢鱼糜为原料,探究外源添加物(荷叶粉、荷叶水提物、玉米须粉、玉米须水提物、百合粉及百合水提物)对鱼糜凝胶品质的影响及其降尿酸潜在作用。结果表明,不同外源添加物能够不同程度地影响鱼糜凝胶品质,其中,荷叶粉和玉米须粉可显著提高鱼糜凝胶的持水性(P<0.05),荷叶粉、百合水提物及荷叶水提物可显著提高鱼糜凝胶强度(P<0.05)。外源添加物可显著改变鱼糜凝胶的风味与滋味特征,使其风味更加浓郁。同时,与对照组相比,添加外源物质均能够显著增加鱼糜凝胶的黄嘌呤氧化酶体外抑制活性(P<0.05),赋予鱼糜凝胶更高的降尿酸潜力。

二巯丙磺钠对二甲基甲酰胺急性中毒小鼠SOD XOD CAT的影响

目的观察二甲基甲酰胺(DMF)中毒对小鼠氧化酶、抗氧化酶的影响及二巯丙磺钠(Na-DMPS)的保护和治疗作用。方法①48只小鼠,予3g/kg DMF灌胃染毒(ig)后6、12、24、48、72h摘眼球取血及取肝左叶,连同正常组测血及肝匀浆中XOD、SOD、CAT活力。②64只小鼠,分为正常组、中毒对照组、Na-DMPS保护治疗组和单纯保护治疗组,分二批于ig后6h摘眼球取血,ig后24h取肝左叶,测血浆超氧化物歧化酶(SOD)及肝匀浆中SOD、黄嘌呤氧化酶(XOD)、过氧化氢酶(CAT)活力。结果与正常组比较,3g/kg DMF灌胃后血SOD于6h降低(P<0.01),血XOD于72h升高(P<0.05),肝匀浆XOD、SOD、CAT于24h升高(P<0.01)。Na-DMPS保护治疗后,肝组织SOD、XOD较中毒对照组明显下降,差异有统计学意义(P<0.01)。结论Na-DMPS可降低肝组织XOD活性,并对肝脏的SOD升高有降低作用,恢复体内氧化/抗氧化系统的平衡,具有保护肝功能作用,能用于DMF急性中毒的治疗。

抗痛风药物febuxostat的合成

目的合成新型抗痛风药物febuxostat(1)。方法以羟基苯腈为原料,经硫代甲酰化得到对羟基硫代苯甲酰胺(3),3经环合得到2-(4-羟基苯基)-4-甲基-噻唑-5-羧酸乙酯(4),4与乌洛托品反应,得到中间体2-(3-甲酰基-4-羟基苯基)-4-甲基-噻唑-5-羧酸乙酯(5),之后再经醚化、氰化、水解得到目标产物(1)。结果与结论中间体及目标化合物的结构经1H-NMR和FAB-MS确证。该合成路线中使用的原料和试剂价廉易得,反应条件温和易控,操作简便。

泮托拉唑对人肝脏药物代谢酶CYP1A2、NAT2和XO活性影响的研究

目的:探讨泮托拉唑对人肝脏药物代谢酶CYP1A2、NAT2和XO活性的影响,预测泮托拉唑与常用药物的相互作用,指导临床医师合理用药。方法:以咖啡因作为药物代谢酶CYP1A2、NAT2和XO的探针药物,以反相高效液相梯度洗脱法测定30名受试者服用泮托拉唑前后人尿液内咖啡因5种主要代谢产物的相对含量,采用代谢物的比率分别评价人肝脏药物代谢酶CYP1A2、NAT2和XO活性的变化。结果:受试者用药前CYP1A2、NAT2和XO平均活性为3.37±1.22、0.50±0.09、0.49±0.09;服用泮托拉唑7 d后CYP1A2、NAT2和XO平均活性为3.50±1.23、0.48±0.12、0.48±0.13;服药前后3种酶活性没有显著性差异(P>0.05)。结论:泮托拉唑对人肝脏药物代谢酶CYP1A2、NAT2和XO活性无明显影响,泮托拉唑可能不会影响与之合用的需经CYP1A2、NAT2和XO代谢的药物临床疗效。

裙带菜蛋白黄嘌呤氧化酶抑制肽的酶法制备及作用机制

食源性黄嘌呤氧化酶(xanthine oxidase,XO)抑制肽通过抑制XO的催化活力,可降低尿酸生成,缓解高尿酸血症。目前研究聚焦于XO抑制肽的制备,但XO抑制肽的活性有待提高,且其作用机制尚未明确。采用不同蛋白酶水解裙带菜蛋白,经色谱分离和肽段鉴定,筛选出XO抑制肽,并探究其作用机制。裙带菜蛋白经木瓜蛋白酶与黑曲霉酸性蛋白酶(AnproA1)复配水解后,所得水解物的XO抑制率(92.1%)最高。从该水解物中筛选出5条新型XO抑制肽:YLGY、VYW、VVSW、TVVW、KVFAW,其中VYW(IC 50=4.3 mmol/L)和TVVW(IC 50=2.5 mmol/L)具有较高的XO抑制活性。VYW和TVVW的色氨酸残基与XO活性中心及以外位点形成了P i-Pi堆积和P i-Alkyl相互作用,分别表现出非竞争型和竞争型抑制作用。利用木瓜蛋白酶和AnproA1复配水解裙带菜蛋白制备XO抑制肽,将为降尿酸功能性食品配料的开发奠定理论基础。

鼠李糖乳杆菌发酵枸杞汁营养与风味特性及其抗氧化活性和体外抑制黄嘌呤氧化酶活性的研究

本文以药食同源的宁夏枸杞干果(Lyciumbarbarum L.)为原料,利用鼠李糖乳杆菌对其进行发酵,以黄嘌呤氧化酶抑制率为评价指标,通过单因素实验和响应面实验优化发酵工艺,并对发酵枸杞汁的发酵特性、营养和风味特性以及抗氧化活性进行研究。结果表明,鼠李糖乳杆菌发酵枸杞汁的最佳发酵工艺为发酵时间28 h、发酵温度34℃、接种量4%,在此条件下,发酵枸杞汁对黄嘌呤氧化酶的抑制率为79.40%,pH为4.44±0.04,活菌数可达9.5±0.005 lg CFU/mL。与未发酵枸杞汁相比,发酵枸杞汁的可溶性蛋白、总酚和总黄酮含量显著降低(P<0.05),总糖含量增加。此外,GC-IMS分析结果表明发酵后枸杞汁有较多醇类物质产生,增加其独有的发酵香气。体外抗氧化活性分析结果表明发酵后枸杞汁的DPPH自由基清除能力显著提高了186.5%(P<0.05)。

慢性低氧高二氧化碳大鼠大脑超微结构改变和SOD、MDA、XOD变化及红花的保护作用

目的:探讨慢性低氧高二氧化碳大鼠大脑超微结构、超氧化物歧化酶(SOD)、丙二醇(MDA)与黄嘌呤氧化酶(XOD)含量的变化,及红花注射液的保护作用。方法:采用慢性低氧高二氧化碳肺动脉高压模型,应用红花注射液治疗,电镜观察大鼠脑超微结构并测定其SOD、MDA、XOD含量。结果:慢性低氧高二氧化碳使大鼠大脑神经元和神经胶质细胞水肿,伴有细胞内线粒体、内质网、高尔基体等细胞器的变化,并使SOD含量降低,MDA、XOD含量升高。结论:红花注射液对慢性低氧高二氧化碳大鼠大脑神经细胞结构损害有保护作用,其机制可能与抗氧化作用有关。