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71.
Heitaroh Iwata Toshio Matsuda Sadaaki Maeda Akemichi Baba 《Biochimica et Biophysica Acta (BBA)/General Subjects》1979,583(2):159-166
The effect of ascorbic acid on microsomal thiamine diphosphate activity in rat brain was examined. Ascorbic acid at 0.02–0.1 mM increased the thiamine diphosphate activity by 20–600% and produced a significant amount of lipid peroxide, which was measured with thiobarbiturate under the same conditions as the enzyme. A lag period of about 10 min was observed in the process of stimulation of enzyme activity by ascorbic acid. The stimulation of enzyme activity and the lipid peroxidation induced by ascorbic acid were blocked by metal-binding compounds (EDTA, α,α′-dipyridyl, o-phenanthroline) and an antioxidant (N,N′-diphenyl p-phenylenediamine). GSH significantly enhanced the stimulation of enzyme activity and formation of lipid peroxide by 0.02–0.05 mM ascorbic acid. The effect of GSH was due in part to maintenance of the concentration of ascorbic acid in the medium, since GSH could convert dehydroascorbic acid, an oxidized form of ascorbic acid, to ascorbic acid. 相似文献
72.
In this study, new Schiff bases and β-lactam derivatives containing morpholine and thio morpholine nuclei were synthesized. Antimicrobial, antioxidant, antimicrobial and antioxidant properties of all synthesized compounds were investigated and highly effective products were obtained. In this context, new effective structures were introduced to the literature. 相似文献
73.
Nrf2可调节多种抗氧化酶的表达,Nrf2的缺失可能影响机体的运动能力,而低氧可提高机体的抗氧化能力并改善运动能力。为了考察低氧运动对Nrf2基因敲除大鼠运动能力和氧化应激的影响,本研究分别在常氧和低氧环境(12%氧浓度)中对野生型大鼠和Nrf2敲除大鼠进行4周的跑台运动。研究显示,低氧运动可提高野生型大鼠的跑台运动力竭时间,Nrf2敲除可缩短大鼠的力竭时间;低氧运动可上调大鼠的Nrf2 m RNA表达量;Nrf2敲除明显抑制HIF-1α蛋白表达,而低氧运动可上调野生型和Nrf2敲除大鼠的HIF-1α蛋白表达;Nrf2敲除大鼠的骨骼肌ROS水平明显升高,并且低氧均可降低野生型和Nrf2敲除大鼠骨骼肌ROS水平。低氧运动可上调Nrf2敲除大鼠的CAT和GSH-PX蛋白表达。苏木精和伊红(HE)染色显示,Nrf2敲除大鼠在力竭跑台运动完成后出现更严重的骨骼肌病理改变,而低氧运动可减轻骨骼肌损伤。本研究认为,Nrf2敲除导致了大鼠骨骼肌中抗氧化酶的抑制及ROS的过量累积,从而造成了骨骼肌损伤并降低了运动能力。此外,低氧可通过上调Nrf2的表达,进而激活HIF-1α及抗氧化酶活性,从而提高运动能力,并防止骨骼肌损伤。 相似文献
74.
绵马贯众是中国传统常用中药,本研究以温度、时间、超声功率、液料比为影响因子,多糖得率为评价指标,通过响应面法优化超声辅助提取绵马贯众多糖的工艺条件,同时测定其基本理化性质及抗氧化活性。研究结果表明,绵马贯众多糖的最佳提取工艺条件为:温度64℃、时间60 min、超声功率210 W、液料比27 mL/g。此时多糖得率为9.57%,与预测值接近。理化性质分析表明绵马贯众多糖为含少量蛋白的酸性多糖。体外抗氧化研究表明绵马贯众多糖具有很强的DPPH自由基清除活性,IC50值为0.29 mg/mL;较好的羟基自由基清除活性,其IC50值为1.10 mg/mL;对DNA的氧化损伤有显著的保护作用。绵马贯众多糖可以作为一种潜在的抗氧化剂应用于食品和化妆品等领域。 相似文献
75.
Juçara palm tree is considered an important species in the Atlantic forest ecosystem and the exploitation of its fruits is a main sustainable strategy adopted to its maintenance. Among several microorganisms in the juçara fruits, were found lactic acid bacteria (LAB) highly capable of synthesizing exopolysaccharides (EPS). Thus, the EPS synthesized by Leuconostoc pseudomesenteroides JF17 was characterized according to its chemical structure, physicochemical properties and antioxidant activity. HPLC analysis showed that the EPS consisted of a homopolysaccharide composed of glucose units, FT-IR spectroscopy revealed a dextran, confirmed by 1H and 13C NMR spectra which showed the composition of the polysaccharide, d-glucose units bound by α-(1→6). The EPS showed high water retention capacity, 507.812 ± 47.471 %, and may be related to the porous structure revealed by SEM images. Thermal analysis indicated that the EPS had excellent thermal stability with degradation temperature of 320.8 °C and melting point at 279.81 °C, with the enthalpy of 106.557 J/g. The EPS also presented sequestration ability on different free radicals tested, indicating high antioxidant activity. The results suggest that L. pseudomesenteroides JF17 might be widely used in the production of dextran which has potential qualities for applications in the food industry. 相似文献
76.
The effect of a synergized two-step subcritical water extraction (SWE) and simultaneous multi-frequency ultrasound-assisted alcohol/salt aqueous two-phase extraction (MFu-AATPE) on the yield, physicochemical, structural characteristics, and antioxidant activities of Lentinus edodes polysaccharides (LEPs) was investigated. Crude LEP extracted under subcritical extraction (31.14%) was purified using dual and triple frequency ultrasound-assisted aqueous two-phase systems giving a yield of 94.57% and 97% respectively. Compared with the dual-frequency sonication (20/40 kHz), the triple frequency sonication (20/40/60 kHz) gave maximum yield and improved the desalination rate by 33.6%. Congo red analysis revealed triple helix structures. Gas Chromatography analysis showed the existence of mannose, glucose, arabinose, xylose, and galactose whilst spectral similarities were observed through Fourier Transform Infrared Spectroscopy. The average molecular weight (Mw) was 83.6170 Da, 2384 Da and 2387 Da for control, dual and triple frequency samples respectively. Ultrasound treated polysaccharides displayed stronger antioxidant activities against the 2.2-diphenyl;-1 picrylhydrazyl (DPPH), 2, 2ʹ-azino-bis 3-ethylbenzothiazoline-6 sulfonic acid (ABTS) and hydroxyl radicals, thus demonstrating their potency in reducing oxidation. However, the microstructure of the triple frequency treated sample was altered compared to the dual-frequency sample. Therefore, this study demonstrated the efficacy of SWE in crude LEPs extraction and illustrated MFu-AATPE as an efficient technique that selectively isolates polysaccharides and enhances extraction efficiencies. 相似文献
77.
《Journal of Asia》2020,23(2):350-357
Acridids are highly abundant living-organism/major-component in agricultural field, globally. It may act as a dependable bio-indicator species in response to environmental-stress. Antioxidants protect insects by scavenging free radicals. Here, we investigated the dose dependant azadirachtin (C35H44O16 AZT) toxicity on oxidative-biomarker; Alkaline-phosphatase (ALP), malondialdehyde (MDA), non-protein-soluble-thiol (NPSH) and antioxidants like superoxide-dismutase (SOD), catalase (CAT), glutathione-peroxidase (GPx) and amylase of gonads from both sexes and juvenile tissues of common grasshopper, Spathosternum prasiniferum prasiniferum (Walker, 1871). The newly hatched adults (female: male = 1:1) are exposed to 1 to 20 ppm AZT for 48 h and have compared to control and 6 h incubation with same concentration of azadirachtin for in vitro experiments. Both in vivo and in vitro experiment demonstrated significant influences on oxidative biomarkers with increasing antioxidant enzymatic activities in either sex. The male gonads represents decreasing antioxidant enzyme activities compared to female gonads. Lesser protection by CAT and SOD are noticed in male than female in response to AZT exposure. This experiment suggests that azadirachtin increased the major biomarkers with decreasing antioxidant enzyme activities resulting in more free-radicals related threat in adult male gonads. Variable dose responses were noticed on ALP, AchE and MDA in either gender suggesting multiphasic action of the pesticides. Higher mortality rate is noticed in male with lower nymphal life span. Moreover, nymph IInd is more susceptible than nymph IVth in vitro intoxication of azadirachtin. Possible life threat of vast representatives of agricultural ecosystem by pesticide should be avoided to maintain different bio-geo cycle and eco-sustainability. 相似文献
78.
《Saudi Journal of Biological Sciences》2020,27(5):1302-1309
Background and ObjectivesCissus quadrangularis Linn, is a rich bioresource for folk and traditional medicines from ancient times till date. The present study aimed to investigate the free radical scavenging and anticancer efficacy in vitro of the ethanolic and methanolic extract from the aerial parts of Cissus quadrangularis (L).Material and MethodsIn vitro cell-free antioxidant analyses were performed for the ethanolic extract of Cissus quadrangularis (L). (EECQ) and methanolic extract of Cissus quadrangularis (L). (MECQ) using different free radical scavenging assays includes DPPH, nitric oxide, superoxide, metal chelation, and hydrogen peroxide radical scavenging assays. In vitro leukemic cytotoxic assessment by MTT assay was performed both EECQ and MECQ extract against HL-60 cell lines.ResultsStrong antioxidant effects were recorded in EECQ and MECQ in all the cell-free models. The ethanolic extract exhibited a significant dose-dependent free radical activity in comparison with methanolic extracts. The EECQ and MECQ possess pronounced anticancer efficacy against leukemic cells HL-60 with an IC50 value of 36 μg/mL and 40 μg/mL respectively.ConclusionPresent data indicates the presence of marked antioxidant and anticancer behaviors in the extracts of aerial portions of Cissus quadrangularis (L). extracts. Thus, Cissus quadrangularis (L). poses as a promising safe chemopreventive plant to combat cancer. 相似文献
79.
《Saudi Journal of Biological Sciences》2020,27(10):2798-2802
Thimerosal is ethyl mercury based compound which is being used as a preservative in vaccines since decades. Pharmaceutical products and vaccines that contain thimerosal are among the potential source of mercury exposure. Current research was intended to ascertain the reprotoxic effects of thimerosal on rat testes. Twenty-four adult male albino rats were sorted into four groups (n = 6). The first group was a control group. Rats of experimental Group 2, 3 and 4 were treated with various dosages of thimerosal (0.5, 10, 50 mg/kg) respectively. Rats were decapitated after thirty days of trial and different parameters were analyzed. Thimerosal exposure resulted in a significant decrease in antioxidant enzyme activities including catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), glutathione reductase (GSR) and increased levels of thiobarbituric acid reactive substances (TBARS). Different doses of thimerosal significantly decreased (p < 0.05) the concentration of plasma testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH). Additionally, Daily sperm production (DSP) and efficiency of daily sperm production were significantly reduced followed by thimerosal exposure. Moreover, thimerosal significantly (p < 0.05) decreased the primary spermatocytes, secondary spermatocytes, number of spermatogonia along with spermatids. Thimerosal induced adverse histopathological and morphological changes in testicular tissues such as decreased Leydig cells, diameter of seminiferous tubules, tunica albuginea height and epithelial height. On the other hand, the increase in tubular lumen and interstitial spaces was observed due to thimerosal. These outcomes indicated that thimerosal has potential reprotoxic effects in male albino rats. 相似文献
80.
《Saudi Journal of Biological Sciences》2020,27(11):3025-3034
This study was aimed to investigate the anticancer potential of Euphorbia milii (E. milii) using an exquisite combination of phytopharmacological and advanced computational techniques. The chloroform fraction (Em-C) of E. milii methanol extract showed the highest antioxidant activity (IC50: 6.41 ± 0.99 µg/ml) among all studied fractions. Likewise, Em-C also showed significant cytotoxicity (IC50: 11.2 ± 0.8 µg/ml) when compared with that of standard compound 5-fluorouracil (5-FU) (IC50: 4.22 ± 0.6 µg/ml) against hepatocarcinoma cell line (HepG2). However, in a human cervical cancer cell line (HeLa), Em-C demonstrated a non-significant difference in cytotoxicity (22.1 ± 0.8 µg/ml) when compared with that of 5-FU (IC50: 6.87 ± 0.5 µg/ml). Furthermore, Western blot and qRT-PCR analysis revealed that the suppression of HepG2 cells was the consequence of a tremendous decrease in CDK2 and E2F1 protein expression. The GC–MS analysis of Em-C revealed the unique presence of cyclobarbital (CBT) and benzodioxole derivative (BAN) as major constituents. Furthermore, molecular docking of compounds BAN, CBT, and MBT into the binding site of different molecular targets i.e. cyclin dependent kinase 2 (CDK2), thymidylate synthase (TS), caspase 3, BCL2 and topoisomerase II was carried out. Compounds BAN and CBT have demonstrated remarkable binding affinity towards CDK2 and thymidylate synthase, respectively. Molecular dynamic simulation studies have further confirmed the finding of docking analysis, suggesting that CDK2 and TS can act as an attractive molecular target for BAN and CBT, respectively. It can be concluded that these E. milii phytoconstituents (BAN and CBT) may likely be responsible for anti-invasive activity against HepG2 cells. 相似文献