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1.
Electromagnetic induction heating (EMIH) assisted extraction of phenolic compounds from Rosmarinus officinalis L, and the antioxidant and antimicrobial activities of the plant extract were examined in this study. The extraction yield acquired with this process was found to be 25.1?±?2%, with maximum amounts of phenolic compounds: 127.87?±?2.1 mg Gallic acid equivalents per g dry weight and total flavonoids contents 14.48?±?1.5 mg quercetin equivalents per g dry weight, under optimum extraction conditions (extraction time 2 h, ratio of raw material to liquid 1:2 and 0% of NaCl). The antioxidant activity was assessed by the 1,1-diphenyl-2-picrylhydrazyl (DPPH); 2, 2′-azinobis (3-ethylbenzothiazoline-6- sulfonic acid) radical cation (ABTS+) and ferric reducing power (FRAP) methods. The results indicate the extract derived through EMIH showed a strong antioxidant ability (89.25%; EC50 of 0.0148 µg/mL). Besides, the antimicrobial bioassay demonstrated that the extract possessed a good antimicrobial activity against all tested fungi and bacteria.  相似文献   

2.
An endophytic fungus (strain T1) isolated from Taxus baccata was studied for the production of metabolites with anticancer and antioxidant activities. This fungus was identified as Diaporthe sp. based on rDNA-internal transcribed spacer (ITS) sequence analysis. The crude extract showed cytotoxic activity against MCF-7 and HeLa cancer cell lines, with IC50 (concentration inhibiting 50% of growth rate) values of 1058?±?44 and 1257?±?80 μg ml?1, respectively. The scavenging activity of fungal extract increased significantly with increasing concentration [IC50 (concentration required to scavenge 50% of free radicals) 482?±?9 μg ml?1]. Ultra-high-performance liquid chromatography-quadrupole-time of flight analysis revealed the presence of three trichalasins (trichalasin E, F and H) in the crude extract of T1 which are known to have antitumour and antioxidant activities. These results suggest that Diaporthe sp. has the potential to be used for therapeutic purposes because of its antiproliferative and antioxidant potential and also for the production of cytochalasins.  相似文献   

3.
Epidemiological studies have shown that regular consumption of fruits and vegetables is associated with reduced risk of chronic diseases. Vegetables can provide vitamins, phenolics, flavonoids, minerals and dietary fibers for optimal health benefits. However, some nutrients contained in many fruits and vegetables cannot meet of the complete nutrition need in the human body. Biotechnology has the potential to improve the nutritional value of crops. Considering the high consumption of romaine lettuce in human diet worldwide, the objective of study is to enhance the contents of vitamin C, phenolics and antioxidant activity in lettuce leaves by genetic engineering techniques. The gene expression level, vitamin C content, total phenolics, as well as total and cellular antioxidant activities were analyzed by real-time PCR, HPLC, Folin–Ciocalteu, Hydro-PSC and CAA methods, respectively. The bio-fortification of genetically engineered lettuce increased vitamin C up to 48.94 ± 1.34 mg/100 g FW following the increased over-expression of At GLDH. This is almost a 3.2-fold increase as the content when compared with wild type lettuce (p < 0.05). In addition, phenolic compounds in transgenic lettuce contained 120.4 ± 1.62 mg GA equiv./100 g FW, almost double the phenolic content of the wild type. Total antioxidant activities were 735.4 ± 47.7 μmol vitamin C equiv./100 g FW, cellular antioxidant activities were 7.33 ± 0.86 μmol quercetin equiv./100 g FW (PBS wash) and 18.14 ± 0.68 μmol quercetin equiv./100 g FW (No PBS wash) in transgenic lettuce, respectively, 1.5, 4 and twofold increases when compared with the wild type. This study suggests that bio-fortification by genetic engineering has great potential to improve vitamin C, phenolic contents and antioxidant activity in lettuce.  相似文献   

4.
A novel strain of lactic acid bacterium isolated from fermented cucumber was selected due to its high glucansucrase activity. It was identified on the basis of 16S rRNA sequence analysis as Pediococcus pentosaceus CRAG3 (GenBank accession number JX679020). The isolate was round shaped, Gram positive, and catalase negative displaying typical features of lactic acid bacterium. It produced 145 ± 3.27 mg lactic acid per ml of cell-free supernatant. It showed ability to ferment carbohydrates such as sucrose, dextrose, and arabinose; showed resistance to antibiotics such as ciprofloxacin, kanamycin, vancomycin; displayed acid production in triple sugar iron agar test and non-motile nature. Interestingly, the isolate also displayed potential probiotic properties such as hydrophobicity, autoaggregation, coaggregation, and in vitro cell adhesion ability. It exhibited resistance against lysozyme and simulated gastric juice at pH 3.0 with 75 and 58 % survival, respectively. It also showed tolerance toward 0.3 %, w/v bile salts with 73 % survival and ability to deconjugate bile salts. The isolate exhibited antibacterial activity and ability to utilize prebiotics such as inulin and raffinose. These results indicate both probiotic property and glucansucrase-producing ability of P. pentosaceus CRAG3.  相似文献   

5.
This is the first report of induction of haploid callus with significant antioxidant activity from unpollinated ovary cultures of tea. Out of the five cultivars tested, TV18 gave the highest percentage of callus induction. Within 1 wk of induction, ovules swelled to almost double their original size, and white, friable callus emerged. A high cytokinin/auxin ratio, provided by 8.5 μM benzyl adenine and 4.5 μM 2,4-dichlorophenxyacetic acid, and high-temperature treatment (33°C) for 10 d in the dark promoted maximum callus induction. Callus was maintained on MS medium containing 22.2 μM benzyl adenine and 9.8 μM indolebutyric acid (callus line RM 1) in the light at 25°C. Well-developed tracheids were formed within 4 wk in callus subcultured on MS medium containing 1.8 μM thidiazuron and 5.0 μM 2,3,5-triiodobenzoic acid (line RM 2). Flow cytometric analysis revealed that most cells were haploid. Both RM 1 and RM 2 produced phenolic compounds with significant antioxidant capacity. Phenolic content showed a positive linear correlation with antioxidant activity. The total phenolic content of RM 1 was 3.47?±?0.21 gallic acid equivalents (GAE) mg/g dry weight and that of RM 2 was 2.39?±?0.12 GAE mg/g dry weight. Antioxidant activity was measured using IC50, a measure of inhibitory concentration; a lower IC50 value reflects greater antioxidant activity. The IC50 value of RM 1 was 2,530 μg/ml and that of RM 2 was 3,170 μg/ml. The results suggested that the phenolic compounds contributed significantly to the antioxidant capacity of the in vitro cell lines.  相似文献   

6.
Sophora interrupta Bedd, (Fabaceae) is used in Indian folk medicine to treat cancer. Angiogenesis is one of the crucial characteristics of cancer metastasis and is regulated by vascular endothelial growth factor (VEGF). In this study, we examined the antiangiogenic properties of the root ethyl acetate extract of Sophora interrupta by various methods. In vitro antioxidant activity (100–600 μg/ml) of S. interrupta ethyl acetate (SEA) extract was evaluated by DPPH and ABTS, anti-inflammatory activity (50, 100 and 150 μg/ml) by estimating nitric oxide (NO) levels, anti-angiogenic activity (200 and 500 μg/ml) was validated by chorio allantoic membrane (CAM) assay and in silico molecular dynamic (MD) simulations analyses (25 ns) were performed to identify the anti-angiogenic compounds extracted from root extract. The antioxidative activity of SEA extract at IC50 (200?±?0.6 μg/mL) is equal to that of ascorbic acid at IC50 (50?±?0.6 μg/mL), and the anti-inflammatory activity of SEA extract at IC50 (150?±?0.2 μg/mL) was inhibited significantly by nitric oxide (NO) production. The SEA extract significantly reduced the sprouting of new blood vessels at ID50 500?±?0.13 μg/mL in the CAM assay. Gas chromatography–mass spectrometry analysis of the SEA extract detected 34 secondary metabolites, of which 6a,12a-dihydro-6H-(1,3)dioxolo(5,6)benzofuro(3,2-c)chromen-3-ol (maackiain) and funiculosin formed strong hydrogen bond interactions with Lys 920, Thr 916 and Cys 919 (2H), as well as Glu 917 of VEGFR2, and these interactions were similar to those of the anti-angiogenic compound axitinib. Significant findings in all the assays performed indicate that SEA extract has potential anti-angiogenic compounds that may interfere with VEGF-induced cancer malignancy.  相似文献   

7.
The present study was aimed at determining total phenolic and flavonoid contents and studying the antioxidant activity of ginger (Zingiber officinale Rosc.) rhizome and callus, 6-gingerol and 6-shogaol and callus treated with elicitors. Petroleum ether (PE) and chloroform: methanol (1:1, v/v) (CM) extracts were prepared by maceration. Highest total phenolic content was obtained from the CM extract (60.34?±?0.43?mg gallic acid/g) of rhizome while callus showed lower content detected in the CM extract (33.6?±?0.07?mg gallic acid/g). Flavonoids were only detected in rhizome (CM extract 40.25?±?0.21?mg quercetin/g). Both rhizome extracts exhibited good antioxidant activity with higher activity recorded in PE extract (IC50 value 8.29?±?1.73?μg/mL). Callus extracts revealed lower antioxidant activity (IC50 value 1265.49?±?59.9?μg/mL obtained from CM extract). 6-gingerol and 6-shogaol displayed high antioxidant activity in both assays with IC50 4.85?+?0.58DPPH and 5.35?±?0.33ABTS μg/mL for the former and IC50 7.61?±?0.81DPPH and IC50 7.05?±?0.23ABTS μg/mL for the latter. Treatment of callus with elicitors showed significant (p?<?0.05) effects in enhancing phenolic content and related antioxidant activity. The highest significant increase in phenolic content (37% and 34%) and antioxidant activity in DPPH assay (34% and 30%) was observed in callus treated with 100?mg/L yeast extract and 50?mg/L salicylic acid respectively. Therefore, studying the effect of the elicitation of ginger cultured tissues in phenolic accumulation would be of immense importance for pharmacological, cosmetic and agronomic industries.  相似文献   

8.
Macroalgae are currently being explored as novel and sustainable sources of bioactive compounds for both pharmaceutical and nutraceutical applications arising from their antioxidant, anticancer, and antimicrobial activity. In the present study, the antitumoral and antioxidant activities of crude methanolic extracts of the freshwater macroalga Cladophora surera Parodi & Cáceres, harvested from Napostá Creek (Argentina), were investigated in vitro. The antioxidant activity was assessed by DPPH method and polyphenol content using Folin-Ciocalteu phenol reagent. Antitumoral activity was evaluated on the human breast adenocarcinoma cell line MCF-7 by measuring proliferation, migration, and cell adhesion. The algal extract (AE) showed a total phenol content of 1.62?±?0.17 μg GAE mg?1 dry alga and DPPH scavenging activity of 25.03?±?1.99% (10 mg)?1 dry alga. The trypan blue assay after 48 h of treatment indicated that the AE significantly inhibits proliferation in a dose-dependent manner (1–100 μg mL?1), being more effective the highest dose employed, with a concomitant increment in dead cells. However, the colorimetric MTS assay only showed a significant decrease in cell viability at 100 μg mL?1 AE. Using the wound healing assay, we demonstrated that AE inhibits cell migration. Through a cell adhesion assay, we found that AE affects considerably the cell adhesion capacity at all doses probed. Analysis of cell spreading indicated that cell morphology was also affected by AE treatment. These results indicate that C. surera could be a source of valuable bioactive compounds usable as antitumoral preventive therapy for their effects on the regulation of processes involved in metastasis in cells derived from human mammary cancer.  相似文献   

9.
Analyses on biological activities of Gnetum gnemon were done to determine the total phenolic and antioxidants of the plant. Four parts of G. gnemon were used in this study, which were leaf, bark, twig, and seeds of the plant. All parts were extracted in methanol, ethanol, hexane, chloroform and hot water using reflux. The total phenolic content of the plant extracts were determined by using Folin-Ciocalteu method. The results demonstrated that the bark from hot water extract showed the highest total phenolic at 10.71?±?0.01 mg GAE/ FDW, while the lowest was chloroform extract of seed at 2.15?±?0.01 mg GAE/ FDW. The antioxidant activity of the plant extracts were determined by using DPPH and FRAP assays, respectively. The DPPH results showed that all plant extracts demonstrated weak free radical scavenging activity tested at the final concentration of 300 μg/ml. In contrast, the methanolic twig extract showed strong reducing power activity (FRAP) at 83.55?±?1.05%, while the hot water seed extract showed the least activity at 41.86?±?4.22% tested at the final concentration of 300 μg/ml. However, there were no correlation between total phenolics and both antioxidant assays tested.  相似文献   

10.
Evaluation of antioxidant capacities of green microalgae   总被引:2,自引:0,他引:2  
Three strains of green microalgae, Chlorococcum sp.C53, Chlorella sp. E53, and Chlorella sp.ED53 were studied for their antioxidant activities. Crude extracts of these microalgae in hot water and in ethanol were examined for their total phenolic contents and for their antioxidant capacities. In order to determine their phenolic contents, the Folin–Ciocalteu method was used. As for the determination of their antioxidant capacities, four different assays were used: (1) total antioxidant capacity determination; (2) DPPH radical scavenging assay; (3) ferrous ion chelating ability assay; and (4) inhibition of lipid peroxidation (using thiobarbituric acid reactive substance). For all the strains we have studied, their ethanolic extract showed more antioxidant activities than their hot water extract. Categorically, the ethanolic extract of Chlorella sp.E53 exhibited both the highest total phenolic content of 35.5?±?0.14 mg gallic acid equivalent (GAE) g?1 dry weight and the highest DPPH radical scavenging of 68.18?±?0.38 % at 1.4 mg mL?1 (IC50 0.81 mg mL?1), whereas Chlorella sp.ED53 showed both the highest ferrous ion chelation activity of 42.78?±?1.48 % at 1 mg mL?1 (IC50 1.23 mg mL?1) and the highest inhibition of lipid peroxidation of 87.96?±?0.59 % at 4 mg mL?1. This high level of inhibition is comparable to 94.42?±?1.39 % of butylated hydroxytoluene, a commercial synthetic antioxidant, at the same concentration.  相似文献   

11.
This study was carried out to investigate the effects of chromium intake on glycemic control, markers of cardio-metabolic risk, and oxidative stress in infertile polycystic ovary syndrome (PCOS) women candidate for in vitro fertilization (IVF). This randomized double-blind, placebo-controlled trial was done among 40 subjects with infertile PCOS candidate for IVF, aged 18–40 years old. Individuals were randomly allocated into two groups to take either 200 μg/day of chromium (n?=?20) or placebo (n?=?20) for 8 weeks. Biochemical parameters were assessed at baseline and at end-of-trial. Compared with the placebo, taking chromium supplements led to significant reductions in fasting plasma glucose (??2.3?±?5.7 vs. +?0.9?±?3.1 mg/dL, P?=?0.03), insulin levels (??1.4?±?2.1 vs. +?0.4?±?1.7 μIU/mL, P?=?0.004), homeostatic model of assessment for insulin resistance (??0.3?±?0.5 vs. +?0.1?±?0.4, P?=?0.005), and a significant increase in quantitative insulin sensitivity check index (+?0.004?±?0.008 vs. ??0.001?±?0.008, P?=?0.03). In addition, chromium supplementation significantly decreased serum triglycerides (??19.2?±?33.8 vs. +?8.3?±?21.7 mg/dL, P?=?0.004), VLDL- (??3.8?±?6.8 vs. +?1.7?±?4.3 mg/dL, P?=?0.004) and total cholesterol concentrations (??15.3?±?26.2 vs. ??0.6?±?15.9 mg/dL, P?=?0.03) compared with the placebo. Additionally, taking chromium supplements was associated with a significant increase in plasma total antioxidant capacity (+?153.9?±?46.1 vs. ??7.8?±?43.9 mmol/L, P?<?0.001) and a significant reduction in malondialdehyde values (?0.3?±?0.3 vs. +?0.1?±?0.2 μmol/L, P?=?0.001) compared with the placebo. Overall, our study supported that chromium administration for 8 weeks to infertile PCOS women candidate for IVF had beneficial impacts on glycemic control, few variables of cardio-metabolic risk, and oxidative stress.  相似文献   

12.
There is a constant need for novel antibiotic and antioxidant sources due to the ever-increasing resilience of pathogens and the occurrence of chronic diseases. The natural sources of these agents have advantages due to lower production cost, structural variation, and uses of active compounds for pharmaceutical uses. The microbes living in planta termed “endophytes” are alternative sources of host bioactive compounds. In this study, ten endophytic fungi were isolated from Polygonum chinense L. and identified by sequencing of the internal transcribed spacer regions. The fungal strains were fermented and the ethyl acetate extracts were evaluated for antimicrobial and antioxidant capacities. Almost 80% of the endophytes showed antibacterial potency against one or more pathogenic bacteria. Among all strains, Penicillium canescens showed broad-spectrum antimicrobial activity against gram-positive and gram-negative pathogens as well as significant antioxidative and DNA protective capacities. The strain Fusarium chlamydosporum displayed significant anti-radical (126.8?±?6.7 μg/ml) and ferric reducing (84.7?±?2.1 mg AA/g dry extract) capacities. The bio-autography, chromatography, and mass spectroscopy analyses of P. canescens extract revealed the presence of sesquiterpene (germacrene), plasticizer (phthalic acid ester) along with phenolic acids, flavonoid (quercetin), and short chain hydrocarbons. The secondary metabolites of F. chlamydosporum were identified with phenolic acids as bioactive compounds by chromatography and mass spectroscopy. This study indicates P. chinense endophytes as potential sources of antimicrobial and antioxidant compounds for novel drug discovery.  相似文献   

13.
Mucopolysaccharidosis II (MPS II, Hunter syndrome; OMIM 309900) is an X-linked lysosomal storage disease caused by a deficiency in the enzyme iduronate-2-sulfatase (IDS), leading to accumulation of glycosaminoglycans (GAGs). For enzyme replacement therapy (ERT) of Hunter syndrome, two recombinant enzymes, idursulfase (Elaprase®, Shire Human Genetic Therapies, Lexington, MA) and idursulfase beta (Hunterase®, Green Cross Corporation, Yongin, Korea), are currently available in Korea. To compare the biochemical and physicochemical differences between idursulfase and idursulfase beta, we examined the formylglycine (FGly) content, specific enzyme activity, mannose-6-phosphate (M6P) content, sialic acid content, and in vitro cell uptake activity of normal human fibroblasts of these two enzymes. The FGly content, which determines the enzyme activity, of idursulfase beta was significantly higher than that of idursulfase (79.4?±?0.9 vs. 68.1?±?2.2 %, P?<?0.001). In accordance with the FGly content, the specific enzyme activity of idursulfase beta was significantly higher than that of idursulfase (42.6?±?1.1 vs. 27.8?±?0.9 nmol/min/μg protein, P?<?0.001). The levels of M6P and sialic acid were not significantly different (2.4?±?0.1 vs 2.4?±?0.3 mol/mol protein for M6P and 12.3?±?0.7 vs. 12.4?±?0.4 mol/mol protein for sialic acid). However, the cellular uptake activity of the normal human fibroblasts in vitro showed a significant difference (Kuptake, 5.09?±?0.96 vs. 6.50?±?1.28 nM protein, P?=?0.017). In conclusion, idursulfase beta exhibited significantly higher specific enzyme activity than idursulfase, resulting from higher FGly content. These biochemical differences may be partly attributed to clinical efficacy. However, long-term clinical evaluations of Hunter syndrome patients treated with these two enzymes will be needed to demonstrate the clinical implications of significant difference of the enzyme activity and the FGly content.  相似文献   

14.
The filamentous Cyanobacterium Arthrospira is commercially produced and is a functional, high-value, health food. We identified 5 low temperature and low light intensity tolerant strains of Arthrospira sp. (GMPA1, GMPA7, GMPB1, GMPC1, and GMPC3) using ethyl methanesulfonate mutagenesis and low temperature screening. The 5 Arthrospira strains grew rapidly below 14?°C, 43.75 μmol photons m?2 s?1 and performed breed conservation at 2.5?°C, 8.75 μmol photons m?2 s?1. We used morphological identification and molecular genetic analysis to identify GMPA1, GMPA7, GMPB1 and GMPC1 as Arthrospira platensis, while GMPC3 was identified as Arthrospira maxima. Growth at different culture temperatures was determined at regular intervals using dry biomass. At 16?°C and 43.75 μmol photons m?2 s?1, the maximum dry biomass production and the mean dry biomass productivity of GMPA1, GMPB1, and GMPC1 were 2057?±?80 mg l?1, 68.7?±?2.5 mg l?1 day?1, 1839?±?44 mg l?1, 60.6?±?1.8 mg l?1 day?1, and 2113?±?64 mg l?1, 77.7?±?2.5 mg l?1 day?1 respectively. GMPB1 was chosen for additional low temperature tolerance studies and growth temperature preference. In winter, GMPB1 grew well at mean temperatures <10?°C, achieving 3258 mg dry biomass from a starting 68 mg. In summer, GMPB1 grew rapidly at mean temperatures more than 28?°C, achieving 1140 mg l?1 dry biomass from a starting 240 mg. Phytonutrient analysis of GMPB1 showed high levels of C-phycocyanin and carotenoids. Arthrospira metabolism relates to terpenoids, and the methyl-d-erythritol 4-phosphate pathway is the only terpenoid biosynthetic pathway in Cyanobacteria. The 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) gene from GMPB1 was cloned and phylogenetic analysis showed that GMPB1 is closest to the Cyanobacterium Oscillatoria nigro-viridis PCC711. Low temperature tolerant Arthrospira strains could broaden the areas suitable for cultivation, extend the seasonal cultivation time, and lower production costs.  相似文献   

15.
In this study, the probiotic potential of Lactobacillus strains isolated from traditional Kurdish cheese was investigated. The Lactobacillus strains were examined for resistance to gastric acidity and bile toxicity, antimicrobial activities, autoaggregation, coaggregation, hydrophobicity, adhesion to Caco-2 cells, and antibiotic susceptibility. The results showed that all strains tested tolerate acid gastric conditions (pH 2.0 and 3.0), and all of them were bile resistant (at 0.3 and 1 % concentration). Although no antibacterial activity was detected in vitro assay for the treated (neutralized to pH 6.5 and treated with catalase) cell-free culture supernatant (CFCS) of strains, untreated CFCS showed strong antagonistic activity against two known pathogens bacteria. All strains exhibited a strong autoaggregating phenotype and manifested a high degree of coaggregation with pathogens. On the other hand, majority of studied strains were found sensitive to different antibiotics, such as ampicillin, penicillin, ciprofloxacin, chloramphenicol, erythromycin, rifampicin, and tetracycline, and were resistant to vancomycin and streptomycin. Finally, isolated strains showed good hydrophobicity and adherence to Caco-2 cell line, so they could be exploited for food manufacture.  相似文献   

16.
The cyanobacterium Pseudanabaena sp. FACHB 1277, a 2-methylisoborneol (2-MIB) producer isolated from Xionghe Reservoir, was identified by molecular biological methods based on the 16S rDNA sequence. Pseudanabaena sp. FACHB 1277 is a planktonic freshwater species with relatively high 2-MIB per cell density value (7.76?×?10?6 ng cell?1) and specific growth rate (0.25?±?0.01 d?1). The effects of temperature and light intensity on 2-MIB production of Pseudanabaena sp. FACHB 1277 were investigated. Of the six temperatures tested, 10, 15, 20, 25, 30, and 35 °C, the maximum total 2-MIB per cell density and minimum cell density were observed at 10 °C, while the total 2-MIB and dissolved 2-MIB (including extracellular and dissolved intracellular 2-MIB) increased with increasing temperature. Among the six tested light intensities (10, 25, 40, 55, 70, and 85 μmol photons m?2 s?1), the minimum total 2-MIB per cell density and maximum cell density were observed at 25 μmol photons m?2 s?1. The total 2-MIB and extracellular 2-MIB increased with light intensity increasing from 10 to 40 μmol photons m?2 s?1, while no significant increase was observed when the light intensity was higher than 40 μmol photons m?2 s?1. The maximum intracellular 2-MIB (including dissolved and bound) occurred at 25 μmol photons m?2 s?1. The present study indicates that increasing temperature could favor the conversion of bound intracellular to dissolved 2-MIB, while increasing light intensity stimulates the release of dissolved intracellular 2-MIB into the environment.  相似文献   

17.

Flavonoids, a large group of secondary plant phenolic metabolites, are important natural antioxidants and regulators of cellular redox balance. The present study addressed evaluation of the electronic properties of some flavonoids belonging to different classes such as quercetin (flavonols), catechin (flavanols), and naringenin (flavanones) and their interactions with oxidants in model systems of DPPH reduction, flavonoid autoxidation, and chlorination. According to our ab initio calculations, the high net negative excess charges of the C rings and the small positive excess charges of the B rings of quercetin, catechin, and naringenin make these parts of flavonoid molecules attractive for electrophilic attack. The 3′-OH group of the B ring of quercetin has the highest excess negative charge and the lowest energy of hydrogen atom abstraction for the flavonoids studied. The apparent reaction rate constants (s?1, 20 °C) and the activation energies (kJ/mol) of DPPH reduction were 0.34?±?0.06 and 23.0?±?2.5 in the case of quercetin, 0.09?±?0.02 and 32.5?±?2.5 in the case of catechin, respectively. The stoichiometry of the DPPH–flavonoid reaction was 1:1. The activation energies (kJ/mol) of quercetin and catechin autoxidations were 50.8?±?6.1 and 58.1?±?7.2, respectively. Naringenin was not oxidized by the DPPH radical and air oxygen (autoxidation) and the flavonoids studied effectively prevented HOCl-induced hemolysis due to direct scavenging of hypochlorous acid (flavonoid chlorination). The best antioxidant quercetin had the highest value of HOMO energy, a planar structure and optimal electron orbital delocalization on all the phenolic rings due to the C2=C3 double bond in the C ring (absent in catechin and naringenin).

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18.
The present work is focused on the development of thiolated film for fluconazole buccal delivery. To this end, unmodified polymers chitosan and sodium carboxymethylcellulose (NaCMC) backbone was covalently modified by thioglycolic acid (TGA) and cysteine, respectively. The thiolated buccoadhesive film was evaluated in terms of thickness, weight uniformity, water-uptake capacity, drug content, and release patterns. Moreover, mucoadhesion profile was investigated on buccal mucosa. The resulting chitosan–TGA and NaCMC–cysteine conjugates displayed 171?±?13 and 380?±?19 μmol thiol groups per gram of polymer (mean?±?SD; n?=?3), respectively. The water binding capacity of the thiolated film was significantly ~2-fold higher (p?<?0.05) as compared to unmodified film. The obtained thiolated film displayed 5.8-fold higher mucoadhesive properties compared with corresponding film. Controlled release of drugs from film was observed over 8 h. The transport of fluconazole across excised buccal mucosa was enhanced up to 17-fold in comparison with fluconazole applied in buffer. Based on these findings, thiolated film seems to be promising for fluconazole buccal delivery.  相似文献   

19.
Bovine herpesvirus type 5 (BoHV-5) is an important etiologic agent of meningoencephalitis in cattle and has been frequently identified in outbreaks of neurological disease in bovine in the southern hemisphere including Brazil. This study aimed to evaluate the cytotoxic effect and the antiviral properties of extracts obtained from Plocamium brasiliense (Greville) Howe and Taylor in BoHV-5 RJ42/01 replication. The cytotoxic effects were measured in Madin-Darbin bovine kidney cells (MDBK) and cytotoxic concentration (CC50) values have been determined for acyclovir (ACV) (223 μg?±?2.0), ethyl acetate extract from P. brasiliense (2,109 μg?±?10), hexane extract from P. brasiliense (7.181 μg?±?5), dichloromethane extract from P. brasiliense (2.356 μg?±?6.5), and hydroalcoholic extract from P. brasiliense (1.408 μg?±?5.8). As a first approach to characterize the action of these extracts on BoHV-5 RJ42/01, a virucidal assay activity was performed. A virus suspension containing 1?×?105 plaque-forming units (PFU) of the BoHV-5 RJ42/01 was mixed with 600 μg of extract and acyclovir and kept at room temperature (24 °C) for 3 h. Meanwhile, a control of untreated infected virus was performed in the same conditions. Then, treated virus suspension and untreated control were diluted, and percentage of inhibition of infectivity was determined by plaque assay: ethyl acetate extract (99 %), hexane extract (90 %), dichloromethane extract (99 %), and hydroalcoholic extract (27 %). Acyclovir had a slight virucidal activity on viral particle. The inhibition of attachment was performed in MDBK cells inoculated with 100 PFU of BoHV-5 RJ42/01 in the presence or absence of various concentrations of extracts (0.3, 0.9, and 1.5 μg mL?1). Acyclovir was also assayed at 2.8 and 11.25 μg mL?1. The inhibition of adsorption was also tested in MDBK cells treated with the same concentrations of the extracts before virus inoculation. Results: hexane extracts inhibited virus attachment in pre-treated cell 0.9 μg (55 %) and 1.5 μg (71 %) and untreated MDBK cell only with 1.5 μg (63 %). Ethyl acetate extract on cell pre-treated with 0.3 μg (67 %), 0.9 μg (81 %), and 1.5 μg (91 %). Ethyl acetate extract on pre-treated cell 0.3 μg (67 %), 0.9 μg (81 %), and 1.5 (91 %) but discrete inhibition on cell untreated. Dichloromethane extract and acyclovir slightly inhibited virus binding on MDBK cell.  相似文献   

20.

Background

Cancer patients when treated with different chemotherapeutic drugs often develop mild to severe sight threatening diseases during or after chemotherapy. The mechanism involved in the pathogenesis of ocular toxicities is poorly understood. Oxidative stress, inflammation and MMPs (angiogenic factor) are involved in the progression of chemotherapy related ocular disorders.

Materials and methods

The concentration of oxidative stress markers such as MDA, NO and levels of different antioxidant molecules such as SOD, CAT, GSH, GPx, GPr, VIT A, VIT E and VIT C present in the serum of chemotherapy treated patients (n?=?50) and in normal persons (n?=?20) were estimated by the direct spectrophotometric method while the concentration of TNF-α and MMP-9 activity were determined using human TNF-α and MMP-9 ELISA kits.

Results

The concentration of SOD and CAT (0.356?±?0.05?μg/dl and 1.26?±?0.01?μmol/mol of protein) was significantly lower as compared to that (1.09?±?0.03?μg/dl and 3.99?±?0.04?μmol/mol of protein) in controls. The levels of GPx (0.06?±?0.01?mmol/dl) in the cancer patients were much lower than those in the controls (0.78?±?0.06?mmol/dl). Lower level of GSH (0.96?±?0.003?μg/dl) in serum of the diseased group was observed as compared to healthy group (7.26?±?1.40?μg/dl). The level of Vit A, Vit C and Vit E was lower in systemic circulation of cancer patients (109.99?±?6.35?μg/ml, 1.26?±?0.36?μg/ml and 1.29?±?0.191?μg/ml) as compared to control subjects (166.35?±?14.26?μg/ml, 3.25?±?0.099?μg/ml and 6.354?±?2.26?μg/ml) respectively. The concentration of nitric oxide was significantly higher in the cancer patients (45.26?±?6.35?ng/ml) than that in the normal subjects (16.35?±?3.26?ng/ml). The higher concentration of MDA (8.65?±?3.26?nmol/ml) was observed in the patients than normal ones (1.254?±?0.065?nmol/ml). The quantity of TNF-α was significantly higher in chemotherapy treated patients (32.68?±?4.33?pg/ml) as compared to the control group (20.979?±?1.98?pg/ml). Significantly higher concentration of MMP-9 (40.26?±?3.26?ng/ml) was observed in the cancer patients than the controls (7.256?±?1.95?ng/ml).

Conclusion

Lower levels of antioxidant enzymes and non-enzymatic small molecules and higher levels of oxidative stress and inflammatory clinical parameters such as NO, MDA, TNF-α and MMP-9 may be involved in the pathogenesis of systemic chemotherapy related ocular complications such as cataract, glaucoma, blepharitis, retinitis pigmentosa, macular degeneration, pterygium and retinal degeneration.  相似文献   

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