N-acetylcysteine and reduced glutathione reverse flupirtine-induced liver injury and pro⁃duce other beneficial effects in combination with flupirtine

OBJECTIVE To assess whether N-acetylcysteine(NAC)and reduced glutathione(GSH)are effective in reversing flupirtine-induced hepatotoxicity and whether they have other beneficial effects when combined with flupirtine.METHODS The analgesic effects of NAC and flupirtine were first evaluated in carrageenaninduced inflammatory pain and paclitaxel-induced neuropathic pain.The combination subthreshold⁃ing approach was then used to determine whether the combination of NAC and flupirtine produced synergistic analgesic effects.Hepatotoxicity markers and histopathological examination of the liver were used to assess the efficacy of NAC and GSH in reversing flupirtine-induced hepato⁃toxicity.Finally,the effect of GSH on the safe range of flupirtine was assessed in an acute tox⁃icity assay.RESULTS Flupirtine and NAC pro⁃duced dose-dependent antiallodynic effects evoked by carrageenan and paclitaxel in mice.In the above model,the combination of NAC and flupirtine produced an unexpected synergistic analgesic effect.There were no significant differ⁃ences observed in the hepatotoxicity markers and liver histopathology between the experimen⁃tal group and the control group under NAC and GSH treatment.Finally,GSH(200 mg·kg^(-1))expanded the therapeutic index of flupirtine by 1.77 times.CONCLUSION NAC and GSH are effective in preventing liver damage caused by long-term flupirtine use,which provides a solu⁃tion for the safe and effective treatment of chronic pain with flupirtine.In addition,the other benefi⁃cial effects of NAC and GSH when combined with flupirtine may provide the basis for the devel⁃opment of a new therapy with minimal sideeffects and good efficacy.

The effect of glutathione on glucosinolate biosynthesis through the sulfur assimilation pathway in pakchoi associated with the growth conditions

Glucosinolates(GSLs) are a group of nitrogen-and sulfur-containing secondary metabolites, synthesized primarily in members of the Brassicaceae family, that play an important role in food flavor, plant antimicrobial activity, resistance to insect attack, stress tolerance, and human anti-cancer effects. As a sulfur-containing compound, glutathione has a strong connection with GSLs biosynthesis as a sulfur donor or redox system, and exists in reduced(glutathione;GSH) and oxidized(glutathione disulfide;GSSG) forms. However, the mechanism of GSH regulating GSLs biosynthesis remainds unclear. Hence, the exogenous therapy to pakchoi under normal growth condition and sulfur deficiency condition were conducted in this work to explore the relevant mechanism. The results showed that exogenous application of buthionine sulfoximine, an inhibitor of GSH synthesis, decreased the transcript levels of GSLs synthesis-related genes and transcription factors, as well as sulfur assimilation-related genes under the normal growth condition. Application of exogenous GSH inhibited the expression of GSLs synthesis-and sulfur assimilation-related genes under the normal condition, while the GSLs biosynthesis and the sulfur assimilation pathway were activated by exogenous application of GSH when the content of GSH in vivo of plants decreased owing to sulfur deficiency. Moreover,exogenous application of GSSG increased the transcript levels of GSLs synthesis-and sulfur assimilation-related genes under the normal growth condition and under sulfur deficiency. The present work provides new insights into the molecular mechanisms of GSLs biosynthesis underlying glutathione regulation.

生物反馈电刺激疗法对围绝经期女性盆底功能障碍患者血清SOD、GSH-Px水平的影响

目的观察生物反馈电刺激疗法治疗围绝经期盆底功能障碍性疾病(PFD)患者的临床效果及对血清超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)水平的影响。方法收集2019年8月至2022年8月在长沙市第三医院妇产科就诊的204例PFD患者作为研究对象,以随机数字表法分成对照组(102例)与试验组(102例)。对照组给予盆底肌肉锻炼(即Kegel运动),试验组同时联合生物反馈电刺激疗法治疗,比较两组患者临床效果,以及治疗前后盆底肌力、生活质量及血清SOD与GSH-Px水平变化。结果治疗后,试验组总有效率(96.08%)高于对照组(82.35%)[(χ2=4.993,P=0.025)];治疗后,试验组盆底肌力、Ⅰ类/Ⅱ类肌纤维最大值均明显优于对照组[(4.31±0.80)级vs(3.09±0.76)级,(31.69±7.62)uv vs(23.19±7.17)uv,(44.07±12.89)uv vs(34.48±13.15)uv(t=-7.896,-5.802,-3.719,P均<0.01)];治疗后,试验组患者血清SOD、GSH-Px水平明显优于对照组[(5501.28±512.37)pg/mL vs(5096.31±526.42)pg/mL,(824.33±139.69)pmol/L vs(542.68±117.54)pmol/L(t=-3.937,-11.018,P均<0.01)];治疗后,试验组患者盆底功能障碍量表(PFDI-20)总分与其分量表评分以及盆底障碍影响简易量表(PFIQ-7)总分与分量表评分下降显著优于对照组(t=1.967~4.840,P均<0.05)。结论生物反馈电刺激疗法有助于围绝经期女性PFD患者增强盆底肌力,提高血清SOD、GSH-Px水平,提升患者生活质量。

Theoretical Study on GSH Activation Mechanism of a New Type of Glutathione Transferase Gtt2

Glutathione transferases（GSTs） play an important role in the detoxification of xenobiotic/endobiotic toxic compounds. The α-, π-, and/l-classes of cytosolic GSTs have been studied extensively, while Gtt2 from Saccharo- myces cerevisiae, a novel atypical GST, is still poorly understood. In the present study, we investigated the gluta- thione（GSH） activation mechanism of Gtt2 using the density functional theory（DFT） with the hybrid functional B3LYP. The computational results show that a water molecule could assist a proton transfer between the GSH thiol and the N atom of His133. The energy barrier of proton transfer is 46.0 kJ/mol. The GSH activation mechanism and the characteristics of active site are different from those of classic cytosolic GSTs.

Effects of Reduced Glutathione to Centrifuged and Non-centrifuged Fresh Chilled Stallion Semen on Progressive Motility of Spermatozoa over 72 h

The aim of the current study was to evaluate the effects of supplementation of an inexpensive stallion semen extender(Next Generation■ Dr.Kenny’s with Amikacin and K-Penn)with 1 mM of the antioxidant reduced glutathione(GSH)on the progressive motility of cooled stallion semen over a period of 72 h.Both centrifuged and non-centrifuged semen samples were evaluated from six Standardbred stallions collected three times each,with one week between collections for each stallion.For centrifuged samples,non-cushioned centrifugation was done at 750 g for 10 min.All semen samples were extended to a final concentration of 50 million total cells per milliliter and stored in Equine Express II stallion semen shipping containers.Non-centrifuged samples without GSH declined from an initial mean progressive motility of 70.3%at 0 h to 9.1%at 72 h.Non-centrifuged samples with added GSH declined from an initial mean progressive motility of 70.3%at 0 h to 7.1%at 72 h.Centrifuged samples without added GSH declined from an initial mean progressive motility of 70.3%at 0 h to 46.1%at 72 h.Centrifuged samples with added GSH declined from an initial mean progressive motility of 70.3%at 0 h to 40.3%at 72 h.The results of this study did not find significant improvement in the progressive motility over time for spermatozoa prepared in a traditional skim-milk based extender with antibiotics as a result of addition of GSH to either centrifuged or non-centrifuged semen.These findings suggest that centrifugation of fresh chilled extended stallion semen may be a good idea for any semen that may be used at time points greater than 24 h after collection.

Protective Effect of Reduced Glutathione C_(60) Derivative against Hydrogen Peroxide-induced Apoptosis in HEK 293T Cells

Hydrogen peroxide（H_2O_2） and free radicals cause oxidative stress, which induces cellular injuries, metabolic dysfunction, and even cell death in various clinical abnormalities. Fullerene（C_（60）） is critical for scavenging oxygen free radicals originated from cell metabolism, and reduced glutathione（GSH） is another important endogenous antioxidant. In this study, a novel water-soluble reduced glutathione fullerene derivative（C_（60）-GSH） was successfully synthesized, and its beneficial roles in protecting against H_2O_2-induced oxidative stress and apoptosis in cultured HEK 293 T cells were investigated. Fourier Transform infrared spectroscopy and 1H nuclear magnetic resonance were used to confirm the chemical structure of C_（60）-GSH. Our results demonstrated that C_（60）-GSH prevented the reactive oxygen species（ROS）-mediated cell damage. Additionally, C_（60）-GSH pretreatment significantly attenuated H_2O_2-induced superoxide dismutase（SOD） consumption and malondialdehyde（MDA） elevation. Furthermore, C_（60）-GSH inhibited intracellular calcium mobilization, and subsequent cell apoptosis via bcl-2/bax-caspase-3 signaling pathway induced by H_2O_2 stimulation in HEK 293 T cells. Importantly, these protective effects of C_（60）-GSH were superior to those of GSH. In conclusion, these results suggested that C_（60）-GSH has potential to protect against H_2O_2-induced cell apoptosis by scavenging free radicals and maintaining intracellular calcium homeostasis without evident toxicity.

Reduced glutathione alleviates the toxic effect of 6-hydroxydopamine on bone marrow stromal cells

We studied the effect of reduced glutathione on bone marrow stromal cells （BMSCs） treated with 6-hydroxydopamine （6-OHDA）, which shows a toxic effect on dopaminergic neurons. The proliferation of BMSCs treated with 6-OHDA decreased, while that of BMSCs treated with reduced glutathione increased. The proliferation of BMSCs treated with both 6-OHDA and reduced glutathione was significantly higher compared with that treated with 6-OHDA alone. These findings indicate that reduced glutathione alleviates the toxic effect of 6-OHDA on BMSCs.

The effect of reduced glutathione on the chondrogenesis of human umbilical cord mesenchymal stem cells

It has been discussed whether reduced glutathione (GSH) could promote the chondrogenic differentiation ability of human umbilical cord mesenchymal stem cells (hUC-MSCs). hUC-MSCs were isolated from human umbilical cord and their specificity was identified, then induced into cartilage-like cells in chondrogenic induction medium with transforming growth factor beta 1 (TGF-β1), especially with GSH. The morphological change before and after induction was observed through inverted phase contrast microscope, Type II collagen (COL2-A1) and glycosaminoglycan (GAG) were analyzed qualitatively by Toluidine blue and immunofluorescence technique, respectively, the contents of COL2-A1 and GAG were estimated from the determination of hydroxyproline content and Alcian Blue method separately. The mRNA expressions of GAG and COL2-A1 were assayed by real-time fluorescence quantitative PCR. After continuously cultured for 21 days with GSH, Toluidine blue staining and immunofluorescence reaction were all positive in basic induction medium group (group B), basic induction medium +0.5% dimethylsulfoxide (DMSO) group (group BD) and basic induction medium +0.5% DMSO +500 μM GSH group (group BDG). Moreover, compared with group B and group BD, the contents of COL2-A1 and GAG in group BDG relatively increased and the mRNA expression level of COL2-A1 and GAG also comparatively increased (P < 0.05) and both had a significant statistical significance (P < 0.05). So GSH might promote the induction of hUC-MSCs to differentiate into cartilage-like cells.

Role of Exogenous Reduced Glutathione on Time Dependent ^(203)Hg Distribution in Liver and Kidney of a Freshwater Teleost, Anabas testudineus

Time-dependent tissue distribution of mercury(Hg) was studied in a freshwater perch,Anabas testudineus which revealed that the liver and kidneys are the major sites of Hg reten tion. The role of reduced glutathione (GSH) in the clearance of Hg was also investigated to e valuate the ameliorative effect of this nucleophile. For this purpose, the perch was given GSH 15 min before or after they received 203Hg by injection. The fish were then sacrificed at 24 h and 48 h later. The results clearly indicate that exogenous GSH can significantly reduce Hg retention in both the liver and kidneys, demonstrating a direct role of this nucleophile in the amelioration of Hg-induced toxicity in the early phase of intoxication

基于代谢组学分析GSH对霞多丽葡萄酒代谢产物的影响

为探究还原型谷胱甘肽(reduced glutathione,GSH)对霞多丽葡萄酒酒精发酵结束后贮藏5个月期间理化指标、非挥发性代谢物和挥发性代谢物的影响,本研究将5个不同质量浓度的GSH添加到发酵结束后的葡萄酒中,连续测定贮藏5个月过程中基本理化指标、总酚与颜色指数的变化。利用超高效液相色谱-串联质谱法和气相色谱-串联质谱法对添加20 mg/L GSH的酒样(T)和无添加酒样(CK)贮藏5个月后进行广泛靶向代谢组学与挥发性代谢组学分析。结果表明:在5个月的贮藏过程中,不同GSH添加量对白葡萄酒的挥发酸、总酸、pH值无显著影响(P>0.05);对总酚含量、总类黄酮含量、颜色指数以及游离SO_(2)含量这4个指标有影响。在贮藏第5个月时,添加30 mg/L GSH的酒样总酚含量最高,20 mg/L GSH的酒样颜色指数最低,GSH的添加能延缓游离SO2含量的减少;共鉴定出非挥发性代谢物693种,挥发性代谢物816种,以变量重要性投影大于1.0和差异倍数值不小于1.4筛选差异代谢物,共筛选出33种重要的非挥发性差异代谢物和22种挥发性差异代谢物。非挥发性代谢物中,有17种物质下调,16种物质上调,挥发性代谢物中有3种物质下调,19种物质上调。一些酚酸类、脂肪酸以及氨基酸类物质与挥发性代谢物的变化相关。

Reduced-glutathione concentrations in Boleophthalmus pectinirostris tissues exposed to benzo(a)pyrene

The concentrations of reduced-glutathione ( GSH) in liver and ovary of Boleophthalmus pectinirostris are quantified. The concentrations of GSH in the ovary are much higher than that of GSH in the liver(nearly 3 times of the liver). The study also investigates the changes of GSH contents in the two organs while the fishes were exposed to benzo(a)pyrene(BaP) at concentrations of 0, 0.05, 0.2 and 0.5 mg/L respectively for up to a week. The concentrations of GSH in the liver of BaP-exposed fish increased significantly with dose, whereas the concentrations of GSH in the ovary decreased significantly compared to controls. The results suggested that both the liver and the ovary are the primary organ in BaP metabolism, and that the changes of GSH levels may represent an adaptive response or toxic effect to Bap exposure.

Effect of reduced glutathione assisted therapy on immune function, antioxidant function and inflammatory factor in ovarian cancer after chemotherapy

Objective:To investigate the effect of reduced glutathione adjuvant treatment on immune function, antioxidant function and inflammatory cytokines in ovarian cancer patients after chemotherapy.Result:A total of 100 patients with ovarian cancer who were admitted in our hospital from January 2015 to June 2017. According to the enrollment serial number, divided them into research group and control group each 50 cases, the control group was given conventional chemical drug treatment, the research group were given reduced glutathione adjuvant therapy on the basis of chemical therapy. The T lymphocyte subsets, antioxidant indexes MDA, SOD, T-AOC and inflammatory cytokines TNF-α, IL-6, IL-8 levels change in two groups before chemotherapy (T0), 1 month after chemotherapy (T1) and 3 months (T2) were observed.Result: (1) The CD3+,CD4+,CD4+/CD8+ levels at T1 was decreased than T0, and T2 was significantly increased when compared with T1, The CD8+ level at T1 was higher than T0, and the T2 was significantly decreased than T1 in both groups. The levels of the CD3+, CD4+, CD4+/CD8 at T1, T2 in the research group were higher than the control group, while the levels of CD8+ in the research group was lower than the control group. The difference was statistically significant. (2) The level of MDA at T1 was higher than T0, T2 was significantly lower than T1 in both groups. The levels of SOD and T-AOC at T1 were decreased than T0, and T2 was significantly higher than T1. The levels of SOD and T-AOC at T1, T2 in the research group were higher than in the control group, while the MDA level was lower than in the control group. The difference was statistically significant. (3) The levels of TNF-α, IL-6 and IL-8 at T1 in two groups were significantly higher than T0, and the T2 decreased significantly when compared with T1, The levels of TNF-α, IL-6 and IL-8 at T1, T2 in the research group were lower than in the control group. The difference was statistically significant.Conclusion: The reduced glutathione adjuvant chemotherapy for postoperative ovarian cancer can help to protect the body's immune function, antioxidant function and reduce inflammation factor.

Influence on liver function of hepatic artery interventional chemoembolization combined reduced glutathione therapy for elderly patients with advanced liver cancer

Objective:To explore the influence on liver function of hepatic artery interventional chemoembolization combined reduced glutathione therapy for elderly patients with advanced liver cancer.Methods:A total of 120 cases of elderly patients with advanced liver cancer from digestive surgery in-patient department of our hospital during the period of January 2014 and January 2016 were selected as the research object, the patients were divided into two groups by using the random number table method,each for 60 cases.The control group were given conventional drugs chemotherapy, the study group were given hepatic artery interventional chemoembolization combined reduced glutathione therapy, serum liver function indexes of Direct Bilirubin(DBil), Total Bilirubin(TBil), Aspartate Transaminase(AST) and Alanineamino Transferase (ALT)were detected by using automatic biochemical analyzer. Results: The clinical remission rate of study group was significantly higher than the control group, the recurrence rate was obviously lower than the control group,compared between the two groups with statistically significant differences. The average survival time of study group (29.36±6.25) months, was significantly longer than the control group (18.02±4.16) months .Before the treatment, serum DBil, TBil, AST and ALT levels compared between the two groups with no statistically significant differences,after the treatment,the indexes of study group was significantly lower than the control group. The indexes levels compared between pre-therapy and post-therapy in study group with no statistically significant differences, while the indexes levels of post-therapy in the control group were significantly higher than those pre-therapy. Before the treatment, the life quality score compared between the two groups with no statistically significant differences, after treatment,the score of all patients were significantly higher than those pre-therapywhich the score of study group was significantly higher than the control group.The incidence rate of drug adverse reactions compared between the two groups with no statistically significant differences.Conclusion: The clinical efficacy of hepatic artery interventional chemoembolization combined reduced glutathione therapy for elderly patients with advanced liver cancer is satisfying, and helps to significantly improve liver function, improve life quality, it is worth popularization and application in the clinical practice.

Effect of the reduced glutathione antioxidation combined with conventional antiviral drugs on hepatic fibrosis in patient with hepatitis b cirrhosis

Objective: To study the effect of the reduced glutathione antioxidation combined with conventional antiviral drugs on hepatic fibrosis in patient with liver cirrhosis. Methods: A total of 300 patients with hepatitis b cirrhosis who were treated in Shangluo Central Hospital between August 2012 and August 2016 were collected and divided into the control group (n=159) who received conventional antiviral therapy and the observation group (n=141) who received reduced glutathione antioxidation combined with conventional antiviral drug therapy. The differences in serum levels of fibrosis indicators, inflammatory factors and oxidative stress indexes were compared between the two groups of patients before and after treatment. Results: Before treatment, differences in serum levels of fibrosis indexes, inflammatory factors and oxidative stress indexes were not statistically significant between two groups of patients. After treatment, serum HA, Ⅳ-C, LN, PCⅢ, PCT, IL-6, IL-22, IL-31, TNF-α and MDA levels of both groups of patients were lower than those before treatment while GSH-Px and T-SOD levels were higher than those before treatment, and serum HA, Ⅳ-C, LN, PCⅢ, PCT, IL-6, IL-22, IL-31, TNF-α and MDA levels of observation group after treatment were lower than those of control group while GSH-Px and T-SOD levels were higher than those of control group. Conclusion: Reduced glutathione antioxidation combined with conventional antiviral drugs can effectively inhibit the fibrosis process in patients with hepatitis b cirrhosis, which is because that it reduces the degree of inflammation and oxidative stress reaction.

Effect of adjuvant reduced glutathione therapy on vasoactive molecules and oxidative stress in patients with cirrhosis-induced upper gastrointestinal hemorrhage

Objective: To study the effect of adjuvant reduced glutathione therapy on vasoactive molecules and oxidative stress in patients with cirrhosis-induced upper gastrointestinal hemorrhage. Methods: Patients diagnosed with cirrhosis-induced upper gastrointestinal hemorrhage in No. 215 Hospital of Shaanxi Nuclear Industry between June 2015 and March 2017 were selected as the research subjects, and random number table was used to divide them into the GSH group who accepted reduced glutathione combined with conventional therapy and the control group who accepted conventional therapy. Serum levels of liver function indexes, vasoactive molecules and oxidative stress reaction molecules in two groups of patients were detected before treatment and 3 d after treatment. Results: 3 d after treatment, serum ALT, AST, γ-GT, TBIL, PRA, AT-Ⅱ, ALD, MDA, ox-LDL, AOPP and 8-OHdG levels of both groups of patients were significantly lower than those before treatment while SOD, GSH-Px and CAT levels were significantly high than those before treatment, and serum ALT, AST, γ-GT, TBIL, PRA, AT-II, ALD, MDA, ox-LDL, AOPP and 8-OHdG levels of GSH group were significantly lower than those of control group while SOD, GSH-Px and CAT levels were significantly higher than those of control group. Conclusion: The adjuvant reduced glutathione therapy for cirrhosis-induced upper gastrointestinal hemorrhage can improve the liver function, regulate the secretion of vasoactive molecules and reduce the oxidative stress response.

还原型谷胱甘肽联合核苷类似物治疗乙肝肝硬化的临床分析

目的探究乙型肝炎(简称乙肝)肝硬化患者应用还原型谷胱甘肽联合核苷类似物治疗的效果。方法随机选取2020年2月—2023年2月南通市第三人民医院收治的60例乙肝肝硬化患者为研究对象,采用盲摸双色球法分为研究组、参照组,各30例。参照组行常规治疗,研究组采用还原型谷胱甘肽联合核苷类似物治疗。比较两组临床疗效、肝纤维化程度、肝功能及不良反应发生情况。结果干预前,两组肝纤维化程度、肝功能水平比较,差异无统计学意义(P均>0.05)。干预后,研究组临床治疗总有效率(96.67%)高于参照组(80.00%),差异有统计学意义(χ^(2)=4.043,P<0.05)。干预后,研究组肝纤维程度中层粘连蛋白(Laminin,LN)、透明质酸(Hyaluronic,HA)及Ⅳ型胶原(Ⅳ-collagen,Ⅳ-C)水平均低于参照组,差异有统计学意义(P均<0.05)。干预后,研究组肝功能水平中总胆红素(Total Bilirubin,TBIL)、白蛋白(Albumin,ALB)、谷丙转氨酶(Glutamic Pyruvic Transaminase,GPT)及谷草转氨酶(Glutamic Oxaloacetic Transaminase,GOT)水平均优于参照组,差异有统计学意义(P均<0.05)。两组不良反应总发生率比较,差异无统计学意义(P>0.05)。结论乙肝肝硬化患者应用还原型谷胱甘肽联合核苷类似物治疗能够提高其治疗效果,改善肝纤维化程度及肝功能水平,且安全性较高。

茵陈蒿汤联合还原型谷胱甘肽治疗慢性乙型肝炎临床观察

目的探究茵陈蒿汤联合还原型谷胱甘肽对慢性乙型肝炎(CHB)患者的临床疗效。方法选取2020年5月—2022年5月宜丰县人民医院收治的CHB患者60例,依据不同治疗方式分为两组,观察组采用茵陈蒿汤联合还原型谷胱甘肽治疗,对照组采用还原型谷胱甘肽治疗。比较两组肝功能、生活质量评分、临床疗效、不良反应发生率、肝纤维化指标水平等。结果治疗后,两组总胆红素(TBil)比较,差异无统计学意义(P>0.05);观察组天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)低于对照组(P<0.05);观察组社会、环境、躯体、心理评分高于对照组(P<0.05);观察组的Ⅳ型胶原(Ⅳ-C)、层黏连蛋白(LN)、Ⅲ型前胶原(PCⅢ)、透明质酸(HA)指标均明显低于对照组,差异有统计学意义(P<0.05)。观察组治疗总有效率96.67%(29/30)高于对照组的66.67%(20/30)(P<0.05);观察组不良反应低于对照组(P<0.05)。结论茵陈蒿汤联合还原型谷胱甘肽治疗CHB患者,对提升临床疗效、改善肝纤维化指标水平、提升生活质量的意义重大,同时能够改善肝功能指标,降低不良反应。

GSH对低温胁迫下枇杷幼果叶绿体AsA-GSH循环代谢的影响

以3年生"早钟6号"枇杷容器苗为试材,研究不同质量浓度(100,300,500mg·mL-1)谷胱甘肽(GSH)处理对-3℃条件下枇杷幼果叶绿体AsA-GSH循环代谢的影响及其在抗低温胁迫中的作用。低温胁迫下枇杷幼果叶绿体抗氧化剂还原型谷胱甘肽(GSH)和抗坏血酸(AsA)含量下降,抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)、单脱氢抗坏血酸还原酶(MDHAR)和脱氢抗坏血酸还原酶(DHAR)活性受到不同程度的抑制。采用100mg·mL-1的GSH处理可显著提高低温胁迫下枇杷幼果叶绿体GSH,AsA含量以及APX,GR和MDHAR活性,促进AsA-GSH循环,叶绿体清除自由基的能力增强,在枇杷幼果抵抗低温胁迫中发挥作用。

猪肺血管紧张素转化酶提取纯化及还原型谷胱甘肽对其活性抑制作用研究

血管紧张素转化酶(angiotensin-converting enzyme,ACE)在血压调控系统中起到关键作用。该文通过优化盐析、离子交换层析和超滤等步骤从猪肺中分离纯化ACE并研究其酶学性质。以食源ACE抑制肽Ala-Gly-Pro(AGP)为对照抑制剂,研究了还原型谷胱甘肽(reduced glutathione,GSH)对猪肺ACE活性的影响。当猪肺匀浆液蛋白质量浓度在30 mg/mL时,在35℃的条件下进行离子交换层析纯化ACE,酶活回收率分别达75.6%和61.9%,超滤液流速为5.0 mL/min进行超滤,最终ACE的比活为1.9 U/mg,纯化倍数为475倍,酶活回收率为43.4%。在不增加成本的基础上减少了ACE分离纯化过程中的酶损失,提高ACE分离纯化效率,凝胶电泳结果显示猪肺ACE分子质量为160 kDa,酶学性质分析表明纯化后ACE的最适反应温度为37℃,最适反应pH值为7.5,米氏常数K_(m)为2.05 mmol/L,最大反应速率V_(max)为4.64 nmol/L。体外活性实验表明AGP和GSH均能够抑制猪肺ACE的活性,且AGP和GSH对ACE的IC_(50)值分别为564.0、26.2μmol/L,对其抑制类型分别为竞争型抑制和非竞争性抑制,抵制常数K_(i)分别为127.0、15.5μmol/L。该研究为从抗氧化物质中筛选可能对预防高血压有效的降血压肽提供了可能。