Oxidative stress and antioxidant response in a thermotolerant yeast

Abstract Stress tolerance is a key attribute that must be considered when using yeast cells for industrial applications. High temperature is one factor that can cause stress in yeast. High environmental temperature in particular may exert a natural selection pressure to evolve yeasts into thermotolerant strains. In the present study, three yeasts (Saccharomyces cerevisiae, MC4, and Kluyveromyces marxianus, OFF1 and SLP1) isolated from hot environments were exposed to increased temperatures and were then compared with a laboratory yeast strain. Their resistance to high temperature, oxidative stress, and antioxidant response were evaluated, along with the fatty acid composition of their cell membranes. The SLP1 strain showed a higher specific growth rate, biomass yield, and biomass volumetric productivity while also showing lower duplication time, reactive oxygen species (ROS) production, and lipid peroxidation. In addition, the SLP1 strain demonstrated more catalase activity after temperature was increased, and this strain also showed membranes enriched in saturated fatty acids. It is concluded that the SLP1 yeast strain is a thermotolerant yeast with less oxidative stress and a greater antioxidant response. Therefore, this strain could be used for fermentation at high temperatures.

Protective effects of trimetazidine on mitochondral in myocardial ischemia reperfusion rats / 医学研究生学报

Objective:To study the protective effects of trimetazidine (TMZ) on mitochondrial in myocardial ischemia reperfusion rats and its mechanism. Methods: Fifty SD rats were randomly divided into four groups; the pseudooperation group, the saline group and two TMZ treated groups(5 mg/kg and 10 mg/kg). In the pseudooperation group, the coronary artery was not ligated, but the chest was opened. Other groups were subjected to myocardial ischemia reperfusion injury. The serum level of mal onaldehyole ( MDA ) , superoxide dismutase ( SOD ) , glutathione ( GSH ) , glutathione peroxidase (GSH-PX) and the accumulation of Ca2+ in myocardial mitochondrial were detected at the time of 30 min ischemia and 40 min reperfusion. The myocyte ultrastnicture was also observed by electron microscope in the four groups. Results: Compared with the pseudooperation group, the MDA and total Ca2+ were significantly higher and the SOD, GSH, and GSH-PX were significantly lower in saline group and treatment groups. Compared with the saline group, the MDA and total Ca2+ was significantly lower and the SOD, GSH, and GSH-PX were significantly higher in the treatment groups. Conclusion: TMZ could significantly reduce lipid peroxidation in myocardial mitochondrial induced by ischemia and ische-mia-reperfusion. The mechanism may be that TMZ could increase the content of GSH and the acvitity of SOD and GSH-PX, and enhance its antioxidant production. TMZ could protect the cardiac cells by reducing calcium overload in myocardial mitochondrial.

Sodium Tonshinone Ⅱ_A sulfonat against myocardial reperfusion injury / 中华麻醉学杂志

The experiment was done to explore the effect of sodium Tanshinone Ⅱ_A, sulfonat (STS) on myocardial reperfusion injury. Myocardial ischemia was induced with the occlusion of left anterior descending coronary artery lasting 30 minutes, and postischemic reperfusion persisted 30 minutes also. Fifty rabbits were randomly divided in to five groups: operative control group (group Ⅰ, n=10), myocardial ischemia group (group Ⅱ, n=10), myocardial ischemia and reperfusion group (group Ⅲ, n=10), receiving intravenous STS 5mg?kg~(_1) 5 mins before the reperfusion (group Ⅳ, n=10) and receiving intravenous STS 5mg?kg~(_1) 10 mins before the ischemia and 5 mins before the reperfusion respectively (group Ⅴ, n=10). As compared with those of group Ⅰ, the amount of myocardial malondialdehyde (MDA) increased significantly in group Ⅱ and Ⅲ (P0.05); the activity of myocardial superoxide dismutase (SOD) decreased in group Ⅲ(P0.05); the serum creatine kinase (CK) activity rose markedly in group Ⅱ, Ⅲ and Ⅳ (P0.05). In comparison with those of group Ⅲ, the amount of MDA reduced and activity of SOD increased in group Ⅳ and Ⅴ (P

Effect of Guyanding Decoction on the Metabolism of Oxygen-derived Free Radicals in Chicken Knee Osteoarthritis / 中药新药与临床药理

Obstract: Objective To study the effect of Guyanding Decoction(GYD) on the metabolism of oxygen-derived free radicals in the chicken model of knee osteoarthritis and to explore its therapeutic mechanism.Method Forty chickens were randomized into 5 groups: normal group,model group,low-dose GYD group,high-dose GYD group and Fenbid group.Low-dose group was administered 5 g/kg GYD and high-dose group with 10 g/kg GYD by gastric gavage.Fenbid group was given Fenbid 0.15 g/kg.The SOD activity and the MAD content in serum were detected in each group.Result The activity of SOD in model group was significantly lower than that in normal group(P 0.05).For the content of MDA,model group had a higher level than normal group(P 0.05).Conclusion The decoction of GYD exerts curative effect on experimental osteoarthritis by improving the activity of SOD,eliminating excessive oxygen-derived free radicals,decreasing the content of MDA,and preventing osteoarthritis patients from the injury of oxygen-derived free radicals.

Correlation between senile mild cognitive impairment and metabolize of oxygen-derived free radicals,acetylcholinesterase,blood lipids and inflammatory mediator / 临床神经病学杂志

Objective To study the correlation between senile mild cognitive impairment (MCI) and metabolize of oxygen-derived free radicals, acetylcholinesterase(AchE), blood lipids and inflammatory mediator. Methods Memory,the levels of superoxide dismutase (SOD), malondialdehyde (MDA), AchE, blood lipids, IL-1? and IL-6 of MIC group(45 cases) and elder healthy group(45 controls) were measured, funther compare and correlative analysis were made.Results Compared with elder healthy group, memory score in each item and memory quotient in MCI group were significantly lower (allP

The protective effect of hyperoxic liquid preconditioning in myocardial ischemia-reperfusion injury in rabbits / 西安交通大学学报(医学版)

Objective To study the protective effect of hyperoxic liquid preconditioning in myocardial ischemia-reperfusion injury. Methods Thirty rabbits were randomly divided into three groups: group A undergoing all procedures except ischemia-reperfusion, group C receiving the routine infusion of hyperoxic liquid 15mL/kg for seven days, and group B receiving the routine treatment infusion of saline instead of hyperoxic liquid 15mL/kg. Seven days later, the myocardial ischemic reperfusion model (I/R) was fabricated, ECG and homodynamic index were monitored simultaneously. Plasma MDA and SOD level was assayed before ligation, 30min after ligation and 1, 2, 3h after reperfusion. Results Hyperoxic liquid preconditioning can lower ST segment and improve index of hemodynamics and significantly reduce myocardial infarction size in group C compared with group B((P