Comparison of photosynthesis and antioxidative protection in Sophora moorcroftiana and Caragana maximovicziana under water stress

This study aims to investigate the protective roles of photosynthetic characteristics and antioxidative systems in the desiccation tolerance of Sophora moorcroftiana and Caragana maximovicziana as they adapt to arid environments. A variety of physiological and biochemical parameters in the leaves of two Leguminosae species were monitored for 1, 7, 14, 21 and 28 d of drought stress. Soil water content decreased from 38.58% to 7.33% after exposure to 28 d of water stress. The photosynthetic carbon-assimilation rates of the two Leguminosae plants decreased for non-stomatal limitation with processing water stress. The malondialdehyde content and cell membrane relative conductivity of the two species increased significantly from 1 to 21 d and then decreased. S. moorcroftiana showed higher superoxide dismutase and peroxidase activities than C. maximovicziana during the 28 d treatment period. However, the catalase activities and proline content of C. maximovicziana were higher than those of S. moorcroftiana before the water stress treatment reached 21 d. Nine physiological and biochemical parameters were selected to comprehensively evaluate the two species＇ drought-resistance by the membership function values（MFV）. The mean MFV indicated that S. moorcroftiana has a relatively stronger drought defense capability than C. maximovicziana. S. moorcroftiana mainly uses carbon-assimilation rate and osmotic adjustment to combat water deficiency.

Antioxidant Protection Mechanisms Reveal Significant Response in Drought-Induced Oxidative Stress in Some Traditional Rice of Assam, India

Drought tolerance levels and antioxidant protection mechanisms were evaluated for 21 traditional rice varieties of Assam, India, along with Sahbhagi Dhan （drought tolerant） and IR64 （drought sensitive） as controls. Drought was imposed in hydroponic culture with polyethylene glycol 6000 （PEG6000） that was initially standardized with different concentrations. All the rice varieties showed apparent decreases in growth characteristics under drought stress （initially at 15% for 7 d followed by 20% PEG6000 for 7 d in Yoshida medium）. On the basis of standard evaluation score （SES）, eight rice varieties showed high drought tolerance which were carried forward for further biochemical analyses. Based on different morpho- physiological parameters, SN03 （Bora）, SN04 （Prosad Bhog）, SN05 （Kola Joha）, SN06 （Helash Bora）, SN08 （Salihoi Bao）, SN12 （Kola Amona）, SN20 （Ronga Bora） and SN21 （Sok-Bonglong） were identified as promising drought tolerant varieties. The non-enzymatic antioxidants activities viz., glutathione, ascorbate and enzymatic antioxidant activities such as superoxide dismutase （SOD）, catalase （CAT）, guaiacol peroxidase （GPX）, ascorbate peroxidase （APX）, glutathione reductase （GR） in shoots and roots of all the selected varieties revealed significant level of protection mechanisms as compared with controls. Enhancement in activities of the overall antioxidant enzymes including SOD, GPX, CAT, GR and APX under drought stress reflects their role in the adaptation process under water stress.

Screening antioxidants for the protection of cochlear sensory cells

Sensory cell damage is a major cause of hearing loss： Sensorineural hearing loss （SNHL） is a common sensory deficit characterized by tissue damage and/or cell death in the cochlea. Moderate and severe SNHL causes deficits in communication, associated with increased isolation from human relationships, and negativly impacts employabflity. Many etiologies have been associated with SNHL： Noise overexposure, certain drugs, inner or middle ear infection or immune-induced inflammation being common. However, the most prevalent form of SNHL is presbycusis or age-related hearing loss, often aggravated by other factors including a history of noise exposure, diabetes or high blood pressure （Wong and Ryan, 2015）. Though systemic steroids are used in the treatment of sudden SNHL, other drugs to prevent or cure hearing loss have not yet been developed. Cochlear sensory cells, known as hair cells （HCs） and neurons have very limited repair capacity. Moreover since these cells do not regenerate, making any loss permanent, prevention of cell damage is critical to protecting hearing.

Tartary buckwheat(Fagopyrum tataricum(L.)Gaertn)protein-derived antioxidant peptides:mechanisms of action and structure-activity relationship in Caco-2 cell models

Excessive reactive oxygen species(ROS)can cause oxidative damage and lead to various metabolic disease.Tartary buckwheat(Fagopyrum tataricum(L.)Gaertn)is a new kind of protein-rich functional food,the protein in which has been proved to have good antioxidant capacity.In this study,in order to further explore the antioxidant mechanism of Tartary buckwheat protein,4 peptides(CR-8,LR-8,GK-10 and SR-12)were isolated and identified from it.H2 O2 was used to induce oxidative damage to Caco-2 cells to evaluate antioxidant capacity of these peptides.The results of superoxide dismutase(SOD),total antioxidant capacity(T-AOC)and mitochondrial membrane potential etc.showed that these peptides have superior antioxidant capacity.CR-8 has the best antioxidant capacity.In order to further clarify the antioxidant mechanism of CR-8,metabolomics was used to analyze related metabolites and metabolic pathways.The results showed that after CR-8 intervention,the content of metabolites such as L-acetyl carnitine has increased.This indicated that CR-8 can improve the antioxidant capacity of damaged cells by intervening in multiple metabolic pathways.This also revealed the anti-oxidant mechanism of tartary buckwheat protein.In conclusion,it provided a theoretical basis for further studying the activity of tartary buckwheat portein and utilizing buckwheat resources.

Protective effects of 5-methoxypsoralen against acetaminophen-induced hepatotoxicity in mice

AIM:To investigate the hepatic protective effects of 5-methoxypsoralen(5-MOP) and to learn if 5-MOP causes hepatotoxicity at protective doses.METHODS:C57BL/6J mice were administrated orally with 5-MOP at doses of 12.5,25 and 50 mg/kg body weight respectively every morning for 4 d before given acetaminophen(APAP) subcutaneously at a dose of 500 mg/kg.The 5-MOP alone group was treated with 5-MOP orally at a dose of 50 mg/kg body weight for 4 d without APAP.Twenty-four hours after APAP administration,blood samples of mice were analyzed for serum enzyme alanine transaminase(ALT),aspartate transaminase(AST),lactate dehydrogenase(LDH) levels,and malondialdehyde(MDA),reduced glutathione(GSH) and oxidized glutathione(GSSG) of liver tissues were measured and histopathologic changes of the liver were observed.RESULTS:Compared with the vehicle control group,the serum levels(IU/L) of ALT,AST and LDH were all increased significantly in APAP group(8355 ± 3940 vs 30 ± 21,P < 0.05;6482 ± 4018 vs 146 ± 58,P <0.05;24627 ± 10975 vs 1504 ± 410,P < 0.05).Compared with APAP group,the serum ALT levels(IU/L)(1674 ± 1810 vs 8355 ± 3940,P < 0.05;54 ± 39 vs 8355 ± 3940,P < 0.05;19 ± 9 vs 8355 ± 3940,P < 0.05),AST levels(IU/L)(729 ± 685 vs 6482 ± 4108,P < 0.05;187 ± 149 vs 6482 ± 4108,P < 0.05;141 ± 12 vs 6482 ± 4108,P < 0.05) and LDH levels(IU/L)(7220 ± 6317 vs 24 627 ± 10 975,P < 0.05;1618 ± 719 vs 24 627 ± 10 975,P < 0.05;1394 ± 469 vs 24 627 ± 10 975,P < 0.05) were all decreased drastically in the three-dosage 5-MOP pretreatment groups.Pretreatment of 5-MOP could attenuate histopathologic changes induced by APAP,including hepatocellular necrosis and infiltration of inflammatory cells,and the effect was dose-dependent.MDA levels(nmol/mg) were decreased by 5-MOP in a dose-dependent manner(0.98 ± 0.45 vs 2.15 ± 1.07,P > 0.05;0.59 ± 0.07 vs 2.15 ± 1.07,P < 0.05;0.47 ± 0.06 vs 2.15 ± 1.07,P < 0.05).The pretreatment of 5-MOP could also increase the GSH/GSSG ratio(3.834 ± 0.340 vs 3.306 ± 0.282,P > 0.05;5.330 ± 0.421 vs 3.306 ± 0.282,P < 0.05;6.180 ± 0.212 vs 3.306 ± 0.282,P < 0.05).In the group treated with 5-MOP but without APAP,the serum enzyme levels,the liver histopathologic manifestation,and the values of MDA and GSH/GSSG ratio were all normal.CONCLUSION:5-MOP can effectively protect C57BL/6J mice from APAP-induced hepatotoxicity and possesses an antioxidative activity,and does not cause liver injury at the protective doses.

Protective effects of ginsenoside Rg1 against hydrogen peroxide-induced injury in human neuroblastoma cells

The active ingredient of ginseng,ginsenosides Rg1,has been shown to scavenge free radicals and improve antioxidant capacity.This study hypothesized that ginsenosides Rg1 has a protective role in human neuroblastoma cells injured by H2O2.Ginsenosides Rg1 at different concentrations（50 and 100 μM） was used to treat H2O2（150 μM）-injured SH-SY5 Y cells.Results demonstrated that ginsenoside Rg1 elevated the survival rate of SH-SY5 Y cells injured by H2O2,diminished the amount of leaked lactate dehydrogenase,and increased superoxide dismutase activity.Ginsenoside Rg1 effectively suppressed caspase-3 immunoreactivity,and contributed to heat shock protein 70 gene expression,in a dose-dependent manner.These results indicate that ginsenoside Rg1 has protective effects on SH-SY5 Y cells injured by H2O2 and that its mechanism of action is associated with anti-oxidation and the inhibition of apoptosis.

Hyperbaric oxygen preconditioning improves postoperative cognitive dysfunction by reducing oxidant stress and inflammation

Postoperative cognitive dysfunction is a crucial public health issue that has been increasingly studied in efforts to reduce symptoms or prevent its occurrence. However, effective advances remain lacking. Hyperbaric oxygen preconditioning has proved to protect vital organs, such as the heart, liver, and brain. Recently, it has been introduced and widely studied in the prevention of postoperative cognitive dysfunction, with promising results. However, the neuroprotective mechanisms underlying this phenomenon remain controversial. This review summarizes and highlights the definition and application of hyperbaric oxygen preconditioning, the perniciousness and pathogenetic mechanism underlying postoperative cognitive dysfunction, and the effects that hyperbaric oxygen preconditioning has on postoperative cognitive dysfunction. Finally, we conclude that hyperbaric oxygen preconditioning is an effective and feasible method to prevent, alleviate, and improve postoperative cognitive dysfunction, and that its mechanism of action is very complex, involving the stimulation of endogenous antioxidant and anti-inflammation defense systems.

Effect of SOD_M on Protective Enzymes in Leaves of Rice during Filling Period

[ Objective ] This study aimed to investigate the effect of superoxide dismutase mimics （ SODM ） on protective enzyme activities of rice during filling pe- riod. [ Method] Hybrid rice and conventional rice varieties were used as experimental materials and sprayed with SODM. Activities of protective enzymes and con- tents of ASA, MDA, H20~ and 02- in rice leaves were determined. [ Result] SODM can significantly increase SOD, POD and CAT activities in leaves of rice dur- ing titling period, maintain the MDA, H202 and 02- contents at retatively low levels, and reduce rice peroxidation. [ Conclusion] SODM enhances the activities of antioxidant protective enzymes in plants and the ability to scavenge reactive oxygen free radicals, thereby delaying the senescence of rice and enhancing the ability of photosynthesis in the middle to late tilling period, which is conducive to improve the yield and quality of rice.

Antioxidant and hepatoprotective effects of Boswellia ovalifoliolata bark extracts

Paracetamol(PCM) hepatotoxicity is related to reactive oxygen species(ROS) formation and excessive oxidative stress; natural antioxidant compounds have been tested as an alternative therapy. This study evaluated the hepatoprotective activity of an alcoholic extract of Boswellia ovalifoliolata(BO) bark against PCM-induced hepatotoxicity. BO extract also demonstrated antioxidant activity in vitro, as well as scavenger activity against 2, 2-diphenyl-1-picrylhydrazyl. Administration of PCM caused a significant increase in the release of transaminases, alkaline phosphatase, and lactate dehydrogenase in serum. Significant enhancement in hepatic lipid peroxidation and marked depletion in reduced glutathione were observed after parac intoxication with severe alterations in liver histology. BO treatment was able to mitigate hepatic damage induced by acute intoxication of PCM and showed a pronounced protective effect against lipid peroxidation, deviated serum enzymatic variables, and maintained glutathione status toward control. The results clearly demonstrate the hepatoprotective effect of BO against the toxicity induced by PCM.