Research progress of ferroptosis regulating lipid peroxidation and metabolism in occurrence and development of primary liver cancer

As a highly aggressive tumor,the pathophysiological mechanism of primary liver cancer has attracted much attention.In recent years,factors such as ferroptosis regulation,lipid peroxidation and metabolic abnormalities have emerged in the study of liver cancer,providing a new perspective for understanding the development of liver cancer.Ferroptosis regulation,lipid peroxidation and metabolic abnormalities play important roles in the occurrence and development of liver cancer.The regulation of ferroptosis is involved in apoptosis and necrosis,affecting cell survival and death.Lipid peroxidation promotes oxidative damage and promotes the invasion of liver cancer cells.Metabolic abnormalities,especially the disorders of glucose and lipid metabolism,directly affect the proliferation and growth of liver cancer cells.Studies of ferroptosis regulation and lipid peroxidation may help to discover new therapeutic targets and improve therapeutic outcomes.The understanding of metabolic abnormalities can provide new ideas for the prevention of liver cancer,and reduce the risk of disease by adjusting the metabolic process.This review focuses on the key roles of ferroptosis regulation,lipid peroxidation and metabolic abnormalities in this process.

Ferroptosis regulating lipid peroxidation metabolism in the occurrence and development of gastric cancer

BACKGROUND Gastric cancer is one of the most common malignant tumors in the world,and its occurrence and development involve complex biological processes.Iron death,as a new cell death mode,has attracted wide attention in recent years.However,the regulatory mechanism of iron death in gastric cancer and its effect on lipid peroxidation metabolism remain unclear.AIM To explore the role of iron death in the development of gastric cancer,reveal its relationship with lipid peroxidation,and provide a new theoretical basis for revealing the molecular mechanism of the occurrence and development of gastric cancer.METHODS The process of iron death in gastric cancer cells was simulated by cell culture model,and the occurrence of iron death was detected by fluorescence microscopy and flow cytometry.The changes of gene expression related to iron death and lipid peroxidation metabolism were analyzed by high-throughput sequencing technology.In addition,a mouse model of gastric cancer was established,and the role of iron death in vivo was studied by histology and immunohistochemistry,and the level of lipid peroxidation was detected.These methods comprehensively and deeply reveal the regulatory mechanism of iron death on lipid peroxidation metabolism in the occurrence and development of gastric cancer.RESULTS Iron death was significantly activated in gastric cancer cells,and at the same time,associated lipid peroxidation levels increased significantly.Through high-throughput sequencing analysis,it was found that iron death regulated the expression of several genes related to lipid metabolism.In vivo experiments demonstrated that increased iron death in gastric cancer mice was accompanied by a significant increase in lipid peroxidation.CONCLUSION This study confirmed the important role of iron death in regulating lipid peroxidation metabolism in the occurrence and development of gastric cancer.The activation of iron death significantly increased lipid peroxidation levels,revealing its regulatory mechanism inside the cell.

Vicious cycle of lipid peroxidation and iron accumulation in neurodegeneration

Lipid peroxidation and iron accumulation are closely associated with neurodegenerative diseases,such as Alzheimer’s,Parkinson’s,and Huntington’s diseases,or neurodegeneration with brain iron accumulation disorders.Mitochondrial dysfunction,lipofuscin accumulation,autophagy disruption,and ferroptosis have been implicated as the critical pathomechanisms of lipid peroxidation and iron accumulation in these disorders.Currently,the connection between lipid peroxidation and iron accumulation and the initial cause or consequence in neurodegeneration processes is unclear.In this review,we have compiled the known mechanisms by which lipid peroxidation triggers iron accumulation and lipofuscin formation,and the effect of iron overload on lipid peroxidation and cellular function.The vicious cycle established between both pathological alterations may lead to the development of neurodegeneration.Therefore,the investigation of these mechanisms is essential for exploring therapeutic strategies to restrict neurodegeneration.In addition,we discuss the interplay between lipid peroxidation and iron accumulation in neurodegeneration,particularly in PLA2G6-associated neurodegeneration,a rare neurodegenerative disease with autosomal recessive inheritance,which belongs to the group of neurodegeneration with brain iron accumulation disorders.

Effect of lipid peroxidation on the allergenicity and functional properties of soybeanβ-conglycinin(7S)and glycinin(11S)

This study aimed to analyze the effect of lipid peroxidation on the allergenicity and functional properties of soybeanβ-conglycinin(7 S)and glycinin(11 S).Oxidation complexes were determined using the lipid peroxidation method.Functional properties were analyzed based on emulsifying and foaming properties.The potential allergenicity was evaluated by in vitro and in vivo methods.The results found that oxidation altered structures of the proteins and resulted in the formation of cross-linked protein polymers.The emulsion and foaming properties of the proteins were improved after oxidation.The IgE-binding capacity of 7 S and11 S reduced after oxidation.KU812 cell assays showed that both histamine and IL-4 release decreased after oxidation treatment.A mouse model showed that oxidation reduced the IgE,IgG,and IgG1 levels,as well as reduced histamine and mMCP-1 release in serum,which might suppress the allergic reaction.In conclusion,the lipid peroxidation treatment likely causes changes to the functional properties of soybean,decreasing the potential allergenicity of 7 S and 11 S.

Anti-lipid peroxidation and protection of liver mitochondria against injuries by picroside Ⅱ

AIM: To investigate the anti-lipid peroxidation and protection of liver mitochondria against injuries in mice with liverdamage by picroside Ⅱ.METHODS: Three animal models of liver damageinduced by carbon tetrachloride (CCl4:0.1 mL/10 g, ip),D-galactosamine (D-GalN: 500 mg/kg,ip) and acetaminophen (AP: 0.15 g/kg, ip) were respectively treated with various concentrations of picroside Ⅱ (5, 10, 20 mg/kg, ig). Then we chose the continuously monitoring method (recommended by International Clinical Chemistry League) to analyze serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) values, Marland method to detect the activity of manganese-superoxide dismutase (SOD) in liver mitochondria, TBA colorimetry to determine the content of malonicdialdehyde (MDA) in liver tissue, DTNB method to evaluate the activity of glutathioneperoxidase (GSH-Px) and Lowry method to detect protein level in liver tissue. Meanwhile, effects of picroside Ⅱ on the activity of ATPase and swelling extent of mitochondria in hepatocytes damaged by AP were also evaluated.RESULTS: Picroside Ⅱ could significantly prevent liver toxicity in the three models of liver damage. It decreased the high levels of ALT and AST in serum induced by theadministration of CCl4, D-GalN and AP, reduced the cellular damage of liver markedly, and appeared to be even more potent than the positive control drug of biphenyl dimethyl dicarboxylate pilules (DDB). In groups treated with different doses of picroside Ⅱ, compared to the model group, the content of MDA in serum decreased evidently, whereas the content of SOD and GSH-Px increased in a dosedependent manner, and the difference was statistically significant. Further, in the study of AP model, picroside Ⅱinhibited AP-induced liver toxicity in mice, enhanced the activity of ATPase, improved the swelling extent of mitochondria and helped to maintain a normal balance of energy metabolism.CONCLUSION: Picroside Ⅱ can evidently relieve hepatocyteinjuries induced by CCl4, D-GalN and AP, help scavenge free radicals, protect normal constructions of mitochondria membrane and enhance the activity of ATPase in mitochondria,thereby modulating the balance of liver energy metabolism, which might be part of the mechanisms of hepatoprotectiveeffects of picroside Ⅱ.

Investigation of heavy metals and lipid peroxidation level in the muscles of Clarias gariepinus from IBI,Gindin-Dorowa and D onga community rivers in Taraba State,Nigeria

Heavy metals have harmful effects on human health,and exposure to these metals has been increased by industrial and anthropogenic activities and modern industrialization.Heavy metals content of the liver tissues was determine d using Atomic Absorption Spectrophotometer method,while lipid peroxidation was carried out.Heavy metals analyzed include;lead(Pb),cadmium(Cd),zinc(Zn),Arsenic(As),and Mercury(Hg).The findings revealed that the heavy metal Zinc(Zn)has high concentrations in the muscles of the fish species,the concentration of this heavy metal Zinc is high in River Gindin Dorowa th a n in River Ibi and River Donga shows less concentration of this heavy metal though it’s above WHO permissible limits.Results revealed that only Zn and Cd were present in the muscle from the three rivers.Pb was found only in the liver from Gindin-Dorowa at the concentration of 0.017 mg/kg,which is not significant(P<0.05)when compared with other locations,while Hg and As were absent in all the muscle samples.The highest concentration of Zn was found in the muscle sample from Gindin-Dorowa(7.450 mg/kg)followed by Ibi(6.16 mg/kg)and the least being Donga(4.365 mg/kg)which are significantly(P<0.05)different from one another.However,there was no significant(P<0.05)difference among the Cd composition of muscle from Gindin-Dorowa(0.025 mg/kg),Donga(0.024 mg/kg)and Ibi(0.015 mg/kg),respectively.The TBA was found in the hepatic tissue sample from Gidin-Dorowa,which has the highest Zn,Cd and no Pb content,followed by Ibi and then the Donga sample.This suggests that there is a positive relationship between heavy metals and the effect of TBA on the hepatic tissues,justifying the fact that heavy metals affect the hepatic tissues of fish,while on the cerebral tissue.In conclusion,it revealed that there is a negative relation between heavy metals and the effect of TBA on the cerebral tissues to protect or save aquatic habitat s of fish quality and aquatic life.

Flower-like tin oxide membranes with robust three-dimensional channels for efficient removal of iron ions from hydrogen peroxide

Membrane technology has become the mainstream process for the production of electronic grade hydrogen peroxide(H_(2)O_(2)).But due to the oxidation degradation of the organic membranes(e.g.polyamide)by the strong oxidative radicals(e.g.OH)generated via the activation of H_(2)O_(2)by iron ions(Fe^(3+)),the short effective lifetime of membranes remains a challenge.Inorganic nano tin oxide(SnO_(2))has great potential for the removal of Fe^(3+)in strongly oxidative H_(2)O_(2)because of its ability to stabilize H2O_(2)and preferentially adsorb Fe^(3+).Herein,we have designed for the first time a flower-like robust SnO_(2)membrane on the ceramic support by in situ template-free one-step hydrothermal method.The three-dimensional loose pore structure in the membrane built by interlacing SnO_(2)nanosheets endows the SnO_(2)membrane with a high specific surface area and abundant adsorption sites(AOH).Based on the coordination complexation and electrostatic attraction between the SnO_(2)surface and Fe^(3+),the membrane shows a high Fe3+removal efficiency(83%)and permeability(24 L·m^(-2)·h^(-1)·MPa^(-1))in H_(2)O_(2).This study provides an innovative and simple approach to designing robust SnO_(2)membranes for highly efficient removal of Fe^(3+)in harsh environments,such as strong oxidation conditions.

Iron-chelating and anti-lipid peroxidation properties of 1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methylpyridin-4-one(CM1)in longterm iron loading β-thalassemic mice

Objective:To evaluate the iron—chelating properties and free—radical scavenging activities of1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methyIpyridin—4-one(CM1) treatment in chronic iron-loaded β-thalassemic(BKO) mice.Methods:The BKO mice were fed with a ferrocene-rich diet and were orally administered with CM1|50 mg/(kg·day)| for 6 months.Blood levels of non-transferrin hound iron,labile plasma iron.ferritin(Ft) and malondialdehyde were determined.Results:The BKO mice were fed with an iron diet for 8 months which resulted in iron overload.Interestingly,the mice showed a decrease in the non—transferrin bound iron,labile plasma iron and malondialdehyde levels,but not the Ft levels after continuous CM1 treatment.Conclusions:CM1 could be an effective oral iron chelator that can reduce iron overload and lipid peroxidation in chronic iron overload β—thalassemic mice.

Preparation of PrFe_(x)Co_(1-x)O_(3)/Mt catalyst and study on degradation of 2-hydroxybenzoic acid wastewater by catalytic wet peroxide oxidation

In this study,the perovskite nanocomposite PrFe_(x)Co_(1-x)O_(3)(Pr(S))was successfully synthesized by the sol-gel method;PrFe_(x)Co_(1-x)O_(3)/Al-pillared montmorillonite(Pr(S)/Mt)catalysts were prepared by impregnation(D)method and solid-melting(G)method,respectively,with Pr(S)as the active component and Al-pillared montmorillonite as the carrier.The catalysts were applied to treat the 2-hydroxybenzoic acid(2-HA)-simulated wastewater by catalytic wet peroxide oxidation(CWPO)technique,and the chemical oxygen demand(COD)removal rate and the 2-HA degradation rate were used as indicators to evaluate the catalytic performance.The results of the experiment indicated that the solid-melting method was more conducive to preparing the catalyst when the Co/Fe molar ratio of 7:3 and the optimal structural properties of the catalysts were achieved.The influence of operating parameters,including reaction temperature,catalyst dosage,H_(2)O_(2)dosage,pH,and initial 2-HA concentration,were optimized for the degradation of 2-HA by CWPO.The results showed that 97.64%of 2-HA degradation and 75.23%of COD removal rate were achieved under more suitable experimental conditions.In addition,after the catalyst was used five times,the degradation rate of 2-HA could still reach 76.93%,which implied the high stability and reusability of the catalyst.The high catalytic activity of the catalyst was due to the doping of Co into PrFeO_(3),which could promote the generation of HO·,and the high stability could be attributed to the loading of Pr(S)onto Al-Mt,which reduced the leaching of reactive metals.The study of reaction mechanism and kinetics showed that the whole degradation process conformed to the pseudo-firstorder kinetic equation,and the Langmuir-Hinshelwood method was applied to demonstrate that catalysis was dominant in the degradation process.

Potential role and therapeutic implications of glutathione peroxidase 4 in the treatment of Alzheimer's disease

Alzheimer's disease is an age-related neurodegenerative disorder with a complex and incompletely understood pathogenesis. Despite extensive research, a cure for Alzheimer's disease has not yet been found. Oxidative stress mediates excessive oxidative responses, and its involvement in Alzheimer's disease pathogenesis as a primary or secondary pathological event is widely accepted. As a member of the selenium-containing antioxidant enzyme family, glutathione peroxidase 4 reduces esterified phospholipid hydroperoxides to maintain cellular redox homeostasis. With the discovery of ferroptosis, the central role of glutathione peroxidase 4 in anti-lipid peroxidation in several diseases, including Alzheimer's disease, has received widespread attention. Increasing evidence suggests that glutathione peroxidase 4 expression is inhibited in the Alzheimer's disease brain, resulting in oxidative stress, inflammation, ferroptosis, and apoptosis, which are closely associated with pathological damage in Alzheimer's disease. Several therapeutic approaches, such as small molecule drugs, natural plant products, and non-pharmacological treatments, ameliorate pathological damage and cognitive function in Alzheimer's disease by promoting glutathione peroxidase 4 expression and enhancing glutathione peroxidase 4 activity. Therefore, glutathione peroxidase 4 upregulation may be a promising strategy for the treatment of Alzheimer's disease. This review provides an overview of the gene structure, biological functions, and regulatory mechanisms of glutathione peroxidase 4, a discussion on the important role of glutathione peroxidase 4 in pathological events closely related to Alzheimer's disease, and a summary of the advances in small-molecule drugs, natural plant products, and non-pharmacological therapies targeting glutathione peroxidase 4 for the treatment of Alzheimer's disease. Most prior studies on this subject used animal models, and relevant clinical studies are lacking. Future clinical trials are required to validate the therapeutic effects of strategies targeting glutathione peroxidase 4 in the treatment of Alzheimer's disease.

One stone two birds:electrochemical and colorimetric dual-mode biosensor based on copper peroxide/covalent organic framework nanocomposite for ultrasensentive norovirus detection

Norovirus(NoV)is regarded as one of the most common causes of foodborne diarrhea in the world.It is urgent to identify the pathogenic microorganism of the diarrhea in short time.In this work,we developed an electrochemical and colorimetric dual-mode detection for NoV based on the excellent dual catalytic properties of copper peroxide/COF-NH_(2)nanocomposite(CuO_(2)@COF-NH_(2)).For the colorimetric detection,NoV can be directly detected by the naked eye based on CuO_(2)@COF-NH_(2)as a laccase-like nonazyme using“peptide-NoV-antibody”recognition mode.The colorimetric assay displayed a wide and quality linear detection range from 1 copy/mL to 5000 copies/mL of NoV with a low limit of detection(LOD)of 0.125 copy/mL.For the electrochemical detection of NoV,CuO_(2)@COF-NH_(2)showed an oxidation peak of copper ion from Cu^(+)to Cu^(2+)using“peptide-NoV-antibody”recognition mode.The electrochemical assay showed a linear detection range was 1-5000 copies/mL with a LOD of 0.152 copy/mL.It's worthy to note that this assay does not need other electrical signal molecule,which provide the stable and sensitive electrochemial detection for NoV.The electrochemical and colorimetric dual-mode detection was used to detect NoV in foods and faceal samples,which has the potential for improving food safety and diagnosing of NoV-infected diarrhea.

Triphenylmethanol Conjugates of Triptorelin as Anti-Lipid Peroxidation Prodrugs

Antioxidants are substances that can prevent or slow damage to cells caused by free radicals, unstable molecules that the body produces as a reaction to environmental and other pressures. Free radicals may play a role in heart disease, cancer and other diseases. If the body cannot process and remove free radicals efficiently, oxidative stress can result. This can harm cells and body function. Free radicals are also known as reactive oxygen species (ROS). In this research, Triptorelin&#174;(TRP) conjugates of triphenylmethanol derivatives (TPMs) were synthesized to evaluate their in vitro lipid peroxidation potency. Comparative lipid peroxidation assays between TRP-TPMs conjugates and the corresponding TPMs derivatives were measured using thiobarbituric reactive substance (TBARS) in a dose- and time-dependent manner following the Fenton’s pathway. Overall, TBARS decreased between 20% - 30% for the treated samples of synthesized conjugates compared to their respective control physical mixtures. These data suggest that TRP-TPMs derivatives can be used to improve the biological activity of TRP.

Curative effect of hydrogen peroxide combined with silver ion disinfection on pelvic floor dysfunction

BACKGROUND Pelvic floor dysfunction(PFD)is related to muscle fiber tearing during childbirth,negatively impacting postpartum quality of life of parturient.Appropriate and effective intervention is necessary to promote PFD recovery.AIM To analyze the use of hydrogen peroxide and silver ion disinfection for vaginal electrodes in conjunction with comprehensive rehabilitation therapy for postpartum women with PFD.METHODS A total of 59 women with PFD who were admitted to the hospital from May 2019 to July 2022 were divided into two groups:Control group(n=27)received comprehensive rehabilitation therapy and observation group(n=32)received intervention with pelvic floor biostimulation feedback instrument in addition to comprehensive rehabilitation therapy.The vaginal electrodes were disinfected with hydrogen peroxide and silver ion before treatment.Intervention for both groups was started 6 weeks postpartum,and rehabilitation lasted for 3 months.Pelvic floor muscle voltage,pelvic floor muscle strength,vaginal muscle voltage,vaginal muscle tone,pelvic floor function,quality of life,and incidence of postpartum PFD were compared between the two groups.RESULTS Before comprehensive rehabilitation treatment,basic data and pelvic floor function were not significantly different between the two groups.After treatment,the observation group showed significant improvements in the maximum voltage and average voltage of pelvic floor muscles,contraction time of type I and type II fibers,pelvic floor muscle strength,vaginal muscle tone,vaginal muscle voltage,and quality of life(GQOLI-74 reports),compared with the control group.The observation group had lower scores on the pelvic floor distress inventory(PFDI-20)and a lower incidence of postpartum PFD,indicating the effectiveness of the pelvic floor biostimulation feedback instrument in promoting the recovery of maternal pelvic floor function.CONCLUSION The combination of the pelvic floor biostimulation feedback instrument and comprehensive rehabilitation nursing can improve pelvic floor muscle strength,promote the recovery of vaginal muscle tone,and improve pelvic floor function and quality of life.The use of hydrogen peroxide and silver ion disinfectant demonstrated favorable antibacterial efficacy and is worthy of clinical application.

A study on relationship of nitric oxide,oxidation,peroxidation,lipoperoxidation with chronic cholecystitis

AIM To study relationship of injury induced bynitric oxide,oxidation,peroxidation,lipoperoxidation with chronic cholecystitis.METHODS The values of plasma nitric oxide(P-NO),plasma vitamin C(P-VC),plasma vitamin E(P-VE),plasma β-carotene(P-β-CAR),plasmalipoperoxides(P-LPO),erythrocyte superoxidedismutase(E-SOD),erythrocyte catalase(E-CAT),erythrocyte glutathione peroxidase(E-GSH-Px)activities and erythrocyte lipoperoxides(E-LPO)level in 77 patients with chronic cholecystitisand 80 healthy control subjects were determined,differences of the above average values betweenthe patient group and the control group anddifferences of the average values betweenpreoperative and postoperative patients wereanalyzed and compared,linear regression andcorrelation of the disease course with the abovedetermination values as well as the stepwiseregression and correlation of the course with thevalues were analyzed.RESULTS Compared with the control group,theaverage values of P-NO,P-LPO,E-LPO weresignificantly increased(P【0.01),and of P-VC, P-VE,P-β-CAR,E-SOD,E-CAT and E-GSH-Pxdecreased(P【0.01)in the patient group.Theanalysis of the linear regression and correlationshowed that with prolonging of the course,thevalues of P-NO,P-LPO and E-LPO in the patientswere gradually ascended and the values of P-VC,P-VE,P-β-CAR,E-SOD,E-CAT and E-GSH-Pxdescended(P【0.01).The analysis of thestepwise regression and correlation indicated thatthe correlation of the course with P-NO,P-VE andP-β-CAR values was the closest.Compared withthe preoperative patients,the average values of P-NO,P-LPO and E-LPO were significantlydecreased(P【0.01)and the average values of P-VC,E-SOD,E-CAT and E-GSH-Px in postoperativepatients increased(P【0.01)in postoperativepatients.But there was no significant difference inthe average values of P-VE,P-β-CAR preoperativeand postoperative patients.CONCLUSION Chronic cholecystitis could inducethe increase of nitric oxide,oxidation,peroxidation and lipoperoxidation.

Mechanisms of Inhibitory Effects of Breviscapine on Lipid Peroxidation in Rat Brain Mitochondria

本文研究了灯盏花素抑制脂质过氧化的作用机制。大鼠脑线粒体脂质过氧化物用硫代巴比妥酸比色法测定。灯盏花素与铁的螯合活性用差示光谱法测定。黄嘌呤黄嘌呤氧化酶（ＸａｎＸＯ）体系产生的超氧阴离子自由基（Ｏ２）及ＦｅＳＯ４Ｈ２Ｏ２体系产生的羟自由基（·ＯＨ）用比色法测定。结果表明：灯盏花素能有效地抑制ＸａｎＸＯ和ＦｅＳＯ４Ｈ２Ｏ２诱导的脑线粒体脂质过氧化反应，其ＩＣ５０分别为９３０１和６２１８μｍｏｌ·Ｌ－１。灯盏花素也能清除ＸａｎＸＯ体系产生的Ｏ２和ＦｅＳＯ４Ｈ２Ｏ２体系产生的·ＯＨ，其ＩＣ５０分别为３２６３和２０２２μｍｏｌ·Ｌ－１。灯盏花素还具有螯合Ｆｅ２＋的活性。由此可见，灯盏花素是在氧自由基与线粒体膜的反应中（１）·ＯＨ的形成（通过与Ｆｅ２＋螯合）（２）脂质过氧化的启动（通过清除Ｏ２和·ＯＨ）两个环节抑制脂质过氧化反应的。

Modulatory effect of pineapple peel extract on lipid peroxidation,catalase activity and hepatic biomarker levels in blood plasma of alcoholinduced oxidative stressed rats

Objective:To investigate the ability of the methanolic extract of pineapple peel to modulate alcohol-induced lipid peroxidation,changes in catalase activities and hepatic biochemical marker levels in blood plasma.Methods:Oxidative stress was induced by oral administration of ethanol(20%w/v) at a dosage of 5 niL/kg bw in rats.After 28 days of treatment,the rats were fasted overnight and sacrificed by cervical dislocation.Blood was collected with a 2 mL syringe by cardiac puncture and was centrifuged at 3000 rpm for 10 min.The plasma was analyzed to evaluate malondialdehyde(MDA),catalase activity,aspartate aminotransferase(AST),alkaline phosphatase(ALP) and alanine aminotransferase(ALT) concentrations.Results:Administration of alcohol caused a drastic increase(87.74%) in MDA level compared with the control.Pineapple peel extract significantly reduced the MDA level by 60.16%at 2.S mL/kg bw.Rats fed alcohol only had the highest catalase activity,treatment with pineapple peel extract at 2.5 mL/kg bw however, reduced the activity.Increased AST,ALP and ALT activities were observed in rats fed alcohol only respectively,treatment with pineapple peel extract drastically reduced their activities. Conclusions:The positive modulation of lipid peroxidation,catalase activities as well as hepatic biomarker levels of blood plasma by the methanolic extract of pineapple peels under alcoholinduced oxidative stress is an indication of its protective ability in the management of alcoholinduced toxicity.

Effects of melatonin on lipid peroxidation and antioxidant enzymes in streptozotocin-induced diabetic rat testis

Aim： To examine the effects of melatonin treatment on lipid peroxidation （LPO） and the activities of antioxidant enzymes in the testicular tissue of streptozotocin （STZ）-induced diabetic rats. Methods： Twenty-six male rats were randomly divided into three groups as follows： group Ⅰ, control, non-diabetic rats （n = 9）; group Ⅱ, STZ-induced, untreated diabetic rats （n = 8）; group Ⅲ, STZ-induced, melatonin-treated （dose of 10 mg/kg·day） diabetic rats （n = 9）. Following 8-week melatonin treatment, all rats were anaesthetized and then were killed to remove testes from the scrotum. Results： As compared to group Ⅰ, in rat testicular tissues of grouap Ⅱ, increased levels of malondialdehyde （MDA） （P 〈 0.01） and superoxide dismutase （SOD） （P 〈 0.01） as well as, decreased levels of catalase （CAT） （P 〈 0.01） and glutathione peroxidase （GSH-Px） （P 〉 0.05） were found. In contrast, as compared to group Ⅱ, in rat testicular tissues of group Ⅲ, levels of MDA decreased （but this decrease was not significant, P 〉 0.05） and SOD （P 〈 0.01） as well as CAT （P 〈 0.05） increased. GSH-Px was not influenced by any of the treatment. Melatonin did not significantly affect the elevated glucose concentration of diabetic group. At the end of the study, there was no significant difference between the melatonin-treated group and the untreated group by means of body and testicular weight. Conclusion： Diabetes mellitus increases oxidative stress and melatonin inhibits lipid peroxidation and might regulate the activities of antioxidant enzymes of diabetic rat testes.

Effects of Water Stress on the Protective Enzyme Activities and Lipid Peroxidation in Roots and Leaves of Summer Maize

A systematic study was conducted to determine the effects of water stress on the activities of protective enzymes and lipid peroxidation in maize. The results showed that, under water stress, the activities of superoxide dismutase （SOD）, catalase （CAT）, and peroxidase （POD） in leaves and roots increased sharply at prophase and metaphase growth stages, such as, male tetrad stage, but then declined towards the physiological maturity. The protective enzyme activities in roots were lower than those in leaves. The content of malondialdehyde （MDA） increased according to the severity of water stress. The content of MDA in roots was lower than that in leaves. The activities of protective enzymes and lipid peroxidation in roots were positively related to that in leaves with most of the correlation coefficients being significant. The content of soluble proteins in roots and leaves decreased with increasing drought stress. The ear characteristics deteriorated and the economic yields of maize decreased significantly under water stress. The main factors that caused reduction of yields were the decrease in the number of ear kernels and 100-kernel weight.

Antioxidant,lipid peroxidation inhibition and free radical scavenging efficacy of a diterpenoid compound sugiol isolated from Metasequoia glyptostroboides

Objective:To investigate the antioxidant enicacy of a biologically active dilerpenoid compound sugiol isolated from Metasequoia glyptostroboides(M.glyptostroboides)in various antioxidant models.Methods:An abietane type diterpenoid sugiol,isolated from ethyl acetate extract of M.glyptostroboides cones,was analyzed for its antioxidant efficacy as reducing power ability and lipid peroxidation inhibition as well as its ability to scavenge free radicals such as 1,1-diphenyl-2-picryl hydrazyl,nitric oxide,superoxide and hydroxyl radicals.Results:The sugiol showed significant and concentration-dependent antioxidant and free radical scavenging activities.Consequently,the sugiol exerted lipid peroxidation inhibitory effect by 76.3%as compared to a-tocopherol(80.13%)and butylaled hydroxyanisole(76.59%).In addition,the sugiol had significant scavenging activities of l,l-diphenyl-2-picryl hydrazyl,nitric oxide,superoxide and hydroxyl free radicals in a concentration-dependent manner by 78.83%,72.42%,72.99%and 85.04%,when compared to the standard compound ascorbic acid(81.69%,74.62%,73.00%and 73.79%)and a-tocopherol/butylated hydroxyanisole(84.09%,78.61%,74.45%and 70.02%),respectively.Conclusions:These findings justify the biological and traditional uses of M.glyptostroboides or its secondary metabolites as confirmed by its promising antioxidant efficacy.