Aqueous extracts of the edible Gracilaria tenuistipitata are protective against H₂O₂-induced DNA damage, growth inhibition, and cell cycle arrest

Potential antioxidant properties of an aqueous extract of the edible red seaweed Gracilaria tenuistipitata (AEGT) against oxidative DNA damage were evaluated. The AEGT revealed several antioxidant molecules, including phenolics, flavonoids and ascorbic acid. In a cell-free assay, the extract exhibited 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity that significantly reduced H?O?-induced plasmid DNA breaks in a dose-response manner (P < 0.001). The AEGT also suppressed H?O?-induced oxidative DNA damage in H1299 cells by reducing the percentage of damaged DNA in a dose-response manner (P < 0.001) as measured by a modified alkaline comet-nuclear extract (comet-NE) assay. The MTT assay results showed that AEGT confers significant protection against H?O?-induced cytotoxicity and that AEGT itself is not cytotoxic (P < 0.001). Moreover, H?O?-induced cell cycle G2/M arrest was significantly released when cells were co-treated with different concentrations of AEGT (P < 0.001). Taken together, these findings suggest that edible red algae Gracilaria water extract can prevent H?O?-induced oxidative DNA damage and its related cellular responses.     

(-)-Epicatechin-3-gallate, a green tea polyphenol is a potent agent against UVB-induced damage in HaCaT keratinocytes

(-)-Epicatechin-3-gallate (ECG) is a polyphenolic compound similar to (-)-epigallocatechin-3-gallate (EGCG) which is abundant in green tea. Numerous workers have proposed that EGCG protects epidermal cells against UVB-induced damage. However, little has been known about whether ECG protects keratinocytes against UVB-induced damage. We decided to investigate the protective effects and underlying mechanisms of ECG on UVB-induced damage. Cell viability was determined by the MTT assay. Activation of ERK1/2, p38 and JNK was analyzed by Western blotting. Intracellular H2O2 production and DNA content was analyzed by flow cytometry. Lipid peroxidation was assayed by colorimetry. In our study, we found that ECG dose-dependently attenuated UVB-induced keratinocyte death. Moreover, ECG markedly inhibited UVB-induced cell membrane lipid peroxidation and H2O2 generation in keratinocytes, suggesting that ECG can act as a free radical scavenger when keratinocytes were photodamaged. In parallel, H2O2-induced the activation of ERK1/2, p38 and JNK in keratinocytes could be inhibited by ECG. UVB-induced pre-G1 arrest leading to apoptotic changes of keratinocytes were blocked by ECG. Taken together, we provide here evidence that ECG protects keratinocytes from UVB-induced photodamage and H2O2-induced oxidative stress, possibly through inhibition of the activation of ERK1/2, p38 and JNK and/or scavenging of free radicals.     

Antioxidant and antiproliferative activity of Stachys glutinosa L. ethanol extract

Ethanol extracts of Stachys glutinosa L. (Lamiaceae) were investigated for antioxidative properties, as well as antiproliferative action on various cell lines. The antioxidant activities were investigated by ABTS (2,2′-azinobis-3-ethylbenzothiazoline-6-sulphonic acid) assay, DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, β-carotene/linoleic acid assay, scavenging of hydrogen peroxide (horseradish peroxidase test), superoxide anion scavenging, and hypochlorous acid scavenging (taurine test). The antioxidant activity was reported as IC₅₀ and reveals antioxidant effects. Antiproliferative effects were measured in vitro on three cell lines: HepG2 (human hepatocarcinoma), MCF7 (breast human adenocarcinoma) and C2C12 (mouse myoblast) cell lines by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The ethanol extract induced variations in cell viability on all cell lines tested. At 200 μg/mL, the effects on cell viability were ? 23%, ? 27% and ? 37%, respectively, for C2C12, MCF7 and HepG2.     

Self-assembled mono- and bilayers on gold electrodes to assess antioxidants—a comparative study

Oxidative stress is considered as an imbalance of reactive species over antioxidants, leading to diseases and cell death. Various methods have been developed to determine the antioxidant potential of natural or synthetic compounds based on the ability to scavenge free radicals. However, most of them lack biological relevance. Here, a gold-based self-assembled monolayer (SAM) was compared with a gold-supported lipid bilayer as models for the mammalian cell membrane to evaluate the free radical scavenging activity of different antioxidants. The oxidative damage induced by reactive species was verified by cyclic and differential pulse voltammetry and measured by the increase of electrochemical peak current of a redox probe. Trolox, caffeic acid (CA), epigallocatechin gallate (EGCG), ascorbic acid (AA), and ferulic acid (FA) were used as model antioxidants. The change in the decrease of the electrochemical signal reflecting oxidative membrane damage confirms the expected protective role. Both model systems showed similar efficacies of each antioxidant, the achieved order of radical scavenging potential is as follows: Trolox > CA > EGCG > AA > FA. The results showed that the electrochemical assay with SAM-modified electrodes is a stable and powerful tool to estimate qualitatively the antioxidative activity of a compound with respect to cell membrane protection against biologically relevant reactive species.

     

Antioxidant effects of photodegradation product of nifedipine

Recently, increasing evidence suggests that the antihypertensive drug nifedipine acts as a protective agent for endothelial cells, and that the activity is unrelated to its calcium channel blocking. Nifedipine is unstable under light and reportedly decomposes to a stable nitrosonifedipine (NO-NIF). NO-NIF has no antihypertensive effect, and it has been recognized as a contaminant of nifedipine. The present study for the first time demonstrated that NO-NIF changed to a NO-NIF radical in a time-dependent manner when it interacted with human umbilical vein endothelial cells (HUVECs). The electron paramagnetic resonance (EPR) signal of NO-NIF radicals in HUVECs showed an asymmetric pattern suggesting that the radicals were located in the membrane. The NO-NIF radicals had radical scavenging activity for 1,1-diphenyl-2-picrylhydrazyl, whereas neither NO-NIF nor nifedipine did. In addition, the NO-NIF radical more effectively quenched lipid peroxides than NO-NIF or nifedipine. Furthermore, NO-NIF attenuated the superoxide-derived free radicals in HUVECs stimulated with LY83583, and suppressed iron-nitrilotriacetic acid (Fe-NTA)-induced cytotoxicity in rat pheochromocytoma (PC12) cells. Our findings suggest that NO-NIF is a candidate for a new class of antioxidative drugs that protect cells against oxidative stress.     

Cu催化羟基自由基氧化断裂纤维二糖分子糖苷键反应及其在纤维素低温解聚中的应用

纤维素是葡萄糖通过β-1,4-糖苷键链接而成的高聚物,在木质纤维素中含量最高,结构稳定,较难水解.糖苷键的解聚主要有三种方式:酶水解、酸水解以及碱降解.酶解的优点是反应条件温和、副产物少,但存在成本高、活性低等缺点,限制了其大规模的工业化生产.碱水解纤维素的同时伴随着葡萄糖的peeling-off反应得到异变糖酸,需要消耗大量的碱,并且强碱也存在腐蚀性强和回收难等问题.酸水解是目前工业上常用的纤维素水解方法,在保持较高葡萄糖选择性的同时,通过对反应条件的控制(提高反应温度和酸浓度)来提高纤维素的水解效率,但是硫酸对设备的腐蚀性强,也难以回收,不符合绿色化学的发展要求.固体酸是近年来研究较多的纤维素水解催化剂.固体酸虽然腐蚀性弱、易回收,但是其活性低,水热稳定性较差,目前还不具备大规模生产的条件.本文发展了一种羟基自由基活化断裂糖苷键的方法,利用羟基自由基的高活性在低温下实现糖苷键的选择性断裂,同时羟基自由基与糖苷键作用后转化为无毒无害的水和氧气,将不会对环境造成污染.我们首先以纤维二糖作为纤维素的模型分子,通过羟基自由基能够优先与糖苷键反应得到葡萄糖和葡萄糖酸的实验证实所提出的方法的可行性.实验表明,来自H2O2的·OH自由基能够在铜基催化剂作用下选择性氧化断裂其糖苷键,生成葡萄糖和葡萄糖酸.比如:采用均相CuSO4体系,纤维二糖转化率约为20%时,葡萄糖和葡萄糖酸的选择性分别为28.5%和32.3%.采用多相CuO/SiO2(4 wt%CuO)体系,纤维二糖转化率约为20%时,葡萄糖和葡萄糖酸的选择性约分别为23.3%和25.7%,并且该催化剂具有良好的循环使用性能.与·OH类似,CuSO4催化过硫酸钾生成的·SO4-自由基也能够有效转化纤维二糖,在纤维二糖转化率为20%时,葡萄糖和葡萄糖酸的选择性分别为36.6%和39.9%.利用这种·OH和·SO4-自由基氧化的方法,也能够在较低温度下(333 K)解聚纤维素中的糖苷键.我们发展了H2O2浸渍预处理纤维浸渍预处理纤维素的方法,通过部分破坏纤维素糖苷键,提高了纤维素的水解活性.比如:处理后的纤维素在413 K条件下反应12 h,纤维素转化率和葡萄糖选择性分别达到约36.1%和42.5%.XRD结果表明,处理后的纤维素的晶体结构未发生明显的变化.FT-IR表征结果显示处理后的纤维素表面生成了大量的羧酸基团.     

Oak gum mediated green synthesis of silver nanoparticles under ultrasonic conditions: Characterization and evaluation of its antioxidant and anti-lung cancer effects

Herein, we represent the bio-synthesis of silver nanoparticles (Ag NPs) employing Oak gum as the green template, an efficient natural and non-toxic reductant and stabilizer based on its phytochemicals by using ultrasonic irradiation. The characterization of as-synthesized Ag NPs was performed through Fourier transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), elemental mapping, UV–Vis and X-ray diffraction (XRD). After the characterization, the synthesized Ag NPs/O. Gum was engaged in biological assays like study of anti-oxidant properties by DPPH mediated free radical scavenging test using MeOH and BHT as reference molecules. Thereafter, on having a significant IC₅₀ value in radical scavenging assay, we extended the bio-application of the desired nanocomposite in anticancer study of A549, Calu6 and H358 human lung cell lines in-vitro through MTT assay. They had very low cell viability and high anti-human lung cancer activities dose-dependently against the cell lines without any cytotoxicity on the normal cell line (MRC-5). The IC₅₀ of Ag NPs/O. Gum was found 161.25, 289.26 and 235.29 µg/mL against A549, Calu6 and H358 cell lines, respectively. Maybe significant anti-human lung cancer potentials of Ag NPs/O. Gum against common lung cancer cell lines are related to their antioxidant activities. So, these results suggest that synthesized Ag NPs/O. Gum as a chemotherapeutic nanomaterial have a suitable anticancer activity against lung cell lines.     

Antioxidant activity of aqueous methanol extracts of Protaetia brevitarsis Lewis (Coleoptera: Scarabaedia) at different growth stages

In this study, we evaluate the antioxidant properties of the various extracts of Protaetia brevitarsis Lewis (Coleoptera: Scarabaedia) at different growth stages. The antioxidant activities of six different extracts from larvae, pupae and imago were measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and singlet oxygen (1O? ). The larval methanol extracts (LME) and imago methanol extracts (IME) displayed the greatest effect in DPPH and ABTS radical scavenging assay, but the activity of water extracts was weaker in the all tested assays. However, LME and IME could be compared to ascorbic acid in 1O? quenching ability (the effective concentrations of 50% 1O? quenching: EC?? 0.174, 0.149 and 0.177?mg?mL?1, respectively). The antioxidant ability of the extracts to scavenge free radicals could significantly change the contents of gallic acid equivalent, an important factor based on the value of R2. The results suggest that our study may contribute to the development of new bioactive products with potential applications to reduce oxidative stress as well as play a vital role in protecting insect organisms against oxidative damage caused by undesirable conditions.     

Photosensitizing potential of ciprofloxacin at ambient level of UV radiation

Ciprofloxacin is a widely used fluoroquinolone drug with broad spectrum antibacterial activities. Clinical experience has shown incidences of adverse effects related to skin, hepatic, central nervous system, gastrointestinal and phototoxicity. India is a tropical country and sunlight is abundant throughout the day. In this scenario exposure to ambient levels of ultraviolet radiation (UV-R) in sunlight may lead to harmful effects in ciprofloxacin users. Phototoxicity assessment of ciprofloxacin was studied by two mouse fibroblast cell lines L-929 and NIH-3T3. Generation of reactive oxygen species (ROS) like singlet oxygen (1O2), superoxide anion radical (O2*-) and hydroxyl radical (*OH) was studied under the exposure of ambient intensities of UV-A (1.14, 1.6 and 2.2 mW cm(-2)), UV-B (0.6, 0.9 and 1.2 mW cm(-2)) and sunlight (60 min). The drug was generating 1O2, O2*- and *OH in a concentration and dose-dependent manner. Sodium azide (NaN3) and 1,4-diazabicyclo 2-2-2-octane (DABCO) inhibited the generation of 1O2. Superoxide dismutase (SOD) inhibited 90-95% O2*- generation. The drug (5-40 microg mL(-1)) was responsible for linoleic acid peroxidation. Quenching study of linoleic acid peroxidation with SOD (25 and 50 U mL(-1)) confirms the involvement of ROS in drug-induced lipid peroxidation. The generation of *OH radical was further confirmed by using specific quenchers of *OH such as mannitol (0.5 M) and sodium benzoate (0.5 M). 2'-deoxyguanosine (2'-dGuO) assay and linoleic acid peroxidation showed that ROS were mainly responsible for ciprofloxacin-sensitized photo-degradation of guanine base. L-929 cell line showed 29%, 34% and 54% reduced cell viability at higher drug concentration (300 microg mL(-1)) under UV-A, UV-B and sunlight, respectively. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay in NIH-3T3 cell line at higher drug concentration (300 microg mL(-1)) showed a decrease in cell viability by 54%, 56% and 59% under UV-A, UV-B and sunlight, respectively. Results of neutral red uptake assay (NRU) in L-929 cell line were in accordance with MTT assay. The NIH-3T3 cell line showed a higher photosensitizing potential than L-929. The phototoxicity end point shows a time- and concentration-dependent statistically significant (P<0.001) damage. Ciprofloxacin produced ROS by Type I and Type II photodynamic reactions, interacted with nucleic acid moiety and inhibited cell viability. Further, UV-induced photo-peroxidation of linoleic acid accorded the involvement of ROS in the manifestation of drug phototoxicity. Appearance of ciprofloxacin-induced phototoxicity at the ambient level of sunlight is a real risk for the people of India and for those of other tropical countries. We suggest that sunlight exposure should be avoided (especially peak hours) during ciprofloxacin treatment.     

Probing chemical induced cellular stress by non-Faradaic electrochemical impedance spectroscopy using an Escherichia coli capacitive biochip

A new capacitive biochip was developed using carboxy-CNT activated gold interdigitated (GID) capacitors immobilized with E. coli cells for the detection of cellular stress caused by chemicals. Here, acetic acid, H(2)O(2) and NaCl were employed as model chemicals to test the biochip and monitored the responses under AC electrical field by non-Faradaic electrochemical impedance spectroscopy (nFEIS). The electrical properties of E. coli cells under different stresses were studied based on the change in surface capacitance as a function of applied frequency (300-600 MHz) in a label-free and noninvasive manner. The capacitive response of the E. coli biochip under normal conditions exhibited characteristic dispersion peaks at 463 and 582 MHz frequencies. Deformation of these signature peaks determined the toxicity of chemicals to E. coli on the capacitive biochip. The E. coli cells were sensitive to, and severely affected by 166-498 mM (1-3%) acetic acid with declined capacitance responses. The E. coli biochip exposed to H(2)O(2) exhibited adaptive responses at lower concentrations (<2%), while at a higher level (882 mM, 3%), the capacitance response declined due to oxidative toxicity in cells. However, E. coli cells were not severely affected by high NaCl levels (513-684 mM, 3-4%) as the cells tend to resist the salt stress. Our results demonstrated that the biochip response at a particular frequency enabled the determination of the severity of the stress imposed by chemicals and it can be potentially applied for monitoring unknown chemicals as an indicator of cytotoxicity.     

Preparation of Antioxidant Protein Hydrolysates from Pleurotus geesteranus and Their Protective Effects on H2O2 Oxidative Damaged PC12 Cells

Pleurotus geesteranus is a promising source of bioactive compounds. However, knowledge of the antioxidant behaviors of P. geesteranus protein hydrolysates (PGPHs) is limited. In this study, PGPHs were prepared with papain, alcalase, flavourzyme, pepsin, and pancreatin, respectively. The antioxidant properties and cytoprotective effects against oxidative stress of PGPHs were investigated using different chemical assays and H₂O₂ damaged PC12 cells, respectively. The results showed that PGPHs exhibited superior antioxidant activity. Especially, hydrolysate generated by alcalase displayed the strongest 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (91.62%), 2,2-azino-bis (3-ethylbenzothia zoline-6-sulfonic acid) (ABTS) radical scavenging activity (90.53%), ferric reducing antioxidant power, and metal ion-chelating activity (82.16%). Analysis of amino acid composition revealed that this hydrolysate was rich in hydrophobic, negatively charged, and aromatic amino acids, contributing to its superior antioxidant properties. Additionally, alcalase hydrolysate showed cytoprotective effects on H₂O₂-induced oxidative stress in PC12 cells via diminishing intracellular reactive oxygen species (ROS) accumulation by stimulating antioxidant enzyme activities. Taken together, alcalase hydrolysate of P. geesteranus protein can be used as beneficial ingredients with antioxidant properties and protective effects against ROS-mediated oxidative stress.     

Ultrasound effects on the antioxidative defense systems of Porphyridium cruentum

Ultrasound is a special physical stimulus that has a variety of biological effects. This study provides a first systemic investigation on the ultrasound-induced oxidation and protection actions of the antioxidant defense system in Porphyridium cruentum. The hydroxyl radical and superoxide anion radical scavenging ability of the cells and the electrolyte leakage of the cell membrane were examined. The change of glutathione and carotenoids produced with/without ultrasonic processing were measured; the enzyme activities of superoxide dismutase, catalase, and membrane bound ATPases (Na(+)/K(+)-ATPase, Ca(2+)/Mg(2+)-ATPase) were evaluated for either ultrasound-treated or untreated P. cruentum. The hydroxyl radical and superoxide anion radical scavenging ability of ultrasound-treated P. cruentum increase 49.8 and 76.0%, respectively, of which the electrolyte leakage and malonyldialdehyde accumulation are also found increased 48.6 and 48.0%, respectively, indicating a state of oxidative stress. A significant enhancement of the activities of superoxide dismutase by 53.5%, catalase, membrane bound ATPases (Na(+)/K(+)-ATPase, Ca(2+)/Mg(2+)-ATPase increased by 67.7 and 69.3%, respectively), and the increment of glutathione and carotenoids production are also observed. These results suggested that oxidative stress manifested by elevated reactive oxygen species levels and malonyldialdehyde contents might be resulted from the biophysical responses of P. cruentum to the physical stimuli, and most likely the enhanced antioxidation ability of the algal cells stimuli by ultrasonic comes from the enhancement of enzymatic and nonenzymatic preventive substances as observed in this work.     

Determination of singlet oxygen quenching and protection of biological systems by various extracts from seed of Rumex crispus L

The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effect and total phenolic contents were evaluated for the screening of singlet oxygen ((1)O(2)) quenching efficacy of various seed extracts from Rumex crispus L. The butanol and ethyl-acetate extracts displayed remarkable effect of DPPH as compared to positive control ascorbic acid. The concentrations (QC(50)) of butanol and ethyl-acetate extracts required to exert 50% reducing effect on (1)O(2) were found to be 116 and 82 μg mL(-1), respectively. Both extracts were also found to protect the in vitro biological system from the detrimental effect of (1)O(2) on type II photosensitization in Escherichia coli, red blood cell, lactate dehydrogenase and histidine. Among all the tested extracts, the ethyl-acetate and butanol extracts contained higher amount of total phenolic contents. The results suggest that our study may contribute to the development of new bioactive products with potential applications to reduce photo-produced oxidative stress involving reactive oxygen species in living organisms.     

Synthesis,characterization and in vitro biological assays of copper(II) and nickel(II) complexes with furan‐­2­‐carboxylic acid hydrazide

Two transition metal complexes, [Cu(FH)₃]⋅2Cl⋅2H₂O and [Ni(FH)₃]⋅2Cl⋅2H₂O, were synthesized from the reactions of furan‐2‐carboxylic acid hydrazide with CuCl₂⋅2H₂O and NiCl₂⋅6H₂O. The synthesized complexes were characterized using analytical and various spectral techniques. The structures of the complexes were determined using single‐crystal X‐ray diffraction. The interactions of the complexes with calf thymus DNA (CT‐DNA) were studied using absorption, fluorescence, cyclic voltammetric and viscosity measurements. The experimental results showed that the complexes could interact with CT‐DNA through intercalation. A gel electrophoresis assay demonstrated the ability of the complexes to cleave pBR322 DNA. The binding interaction of the complexes with bovine serum albumin was investigated using a fluorescence spectroscopic method. The radical scavenging ability, assessed using a series of antioxidant assays involving 2,2‐diphenyl‐2‐picrylhydrazyl radical, hydroxyl radical and nitric oxide radical, showed that the complexes possess significant radical scavenging properties. Further, the in vitro cytotoxic effect of the complexes examined on cancerous cell lines, such as human cervical cancer cells (HeLa) and human breast cancer cell line (MCF‐7), showed that the complexes exhibit significant anticancer activity.     

Ionizing radiation induces blockade of c-Jun N-terminal kinase-dependent cell death pathway in a manner correlated with p21(Cip/WAF1) induction in primary cultured normal human fibroblasts

During radiotherapy of cancer, neighboring normal cells may receive sub-lethal doses of radiation. To investigate whether such low levels of radiation modulate normal cell responses to death stimuli, primary cultured human fibroblasts were exposed to various doses of gamma-rays. Analysis of cell viability using an exclusion dye propidium iodide revealed that the irradiation up to 10 Gy killed the fibroblasts only to a minimal extent. In contrast, the cells efficiently lost their viability when exposed to 0.5-0.65 mM H(2)O(2). This type of cell death was accompanied by JNK activation, and was reversed by the use of a JNK-specific inhibitor SP600125. Interestingly, H(2)O(2) failed to kill the fibroblasts when these cells were pre-irradiated, 24 h before H(2)O(2) treatment, with 0.25-0.5 Gy of gamma-rays. These cytoprotective doses of gamma-rays did not enhance cellular capacity to degrade H(2)O(2), but elevated cellular levels of p21(Cip/WAF1), a p53 target that can suppress H(2)O(2)-induced cell death by blocking JNK activation. Consistently, H(2)O(2)-induced JNK activation was dramatically suppressed in the pre-irradiated cells. The overall data suggests that ionizing radiation can impart normal fibroblasts with a survival advantage against oxidative stress by blocking the process leading to JNK activation.     

Antioxidant and anticancer activity of fresh corm extract from Romulea tempskyana (Iridaceae)

The antioxidant and anticancer properties of a medicinal plant, Romulea tempskyana (R. tempskyana) (Iridaceae) were investigated. The fresh corm water extract of R. tempskyana significantly increased cell viability against H(2)O(2) cytotoxicity(.) The extract also showed high inhibition of the lipid peroxidation activity (78.20%), reducing power (IC(50) 64.99?μg?mL(-1)) activity and hydroxyl (IC(50) 38.66?μg?mL(-1)), superoxide (IC(50) 25.99?μg?ml(-1)) and DPPH (IC(50) 19.88?μg?mL(-1)) radical scavenging activity. On the other hand, treatment of the cells with higher extract concentration showed the anticancer activity inducing cytotoxicity. The extract significantly affected Hepatoma G2 and H1299 cell proliferation (IC(50); 103.79 and 88.15?μg?mL(-1)). The amount of MDA (2-fold and 2.5-fold) and activities of several cellular antioxidant enzymes, including Se-GSPx (30%, 15%), non-Se-GSH-Px (11%, 16%) and GST (17%, 23%) increased in Hepatoma G2 and H1299 cells treated with IC(50) concentrations of extract, respectively. These findings suggest that R. tempskyana extract exhibits antioxidant and carcinogenesis-reducing potential.     

An Improved On-Line HPLC-DPPH Method for the Screening of Free Radical Scavenging Compounds in Water Extracts of Lamiaceae Plants

An on-line HPLC-1,1-diphenyl-2-picrylhydrazyl (DPPH*) method has been improved for the detection of polar and nonpolar radical scavenging compounds from complex plant extracts. Eight water extracts were prepared from steam-distilled essential oil-extracted Lamiaceae plants (Origanum vulgare L., O. Onites L., O. Minutiflorum O. Schwartz et P. H. Davis, O. Syriacum L., Satureja cuneifolia Ten., Thymbra spicata L., Coridothymus capitatus (L.) Reichb. f., Majorana hortensis Moench). After the components within each extract had been separated by reverse phase chromatography using 10% to 100% methanol with 2% acetic acid as a mobile phase, analytes capable of scavenging a citric acid-sodium citrate buffered methanolic DPPH* solution were detected by post-column derivatization at 517 nm. The HPLC-DPPH* on-line method was applied to the qualitative and quantitative analysis of these Lamiaceae plant extracts. There was a strong correlation between the scavenging (negative) peak area and the concentration of the radical scavenging reference substances used. The radical scavenging compounds within the extracts were determined as benzoic acid and hydroxycinnamic acid derivatives, flavonoids and diterpenoids according to their retention time and UV spectral data. Rosmarinic acid and carnosic acid were identified as the dominant radical scavengers in these extracts by this method.     

Activity of Experimental Mouthwashes and Gels Containing DNA-RNA and Bioactive Molecules against the Oxidative Stress of Oral Soft Tissues: The Importance of Formulations. A Bioreactor-Based Reconstituted Human Oral Epithelium Model

Background: DNA-RNA compounds have shown promising protection against cell oxidative stress. This study aimed to assess the cytotoxicity, protective, or preventive effect of different experimental formulations on oral epithelia’s oxidative stress in vitro. Methods: Reconstituted human oral epithelia (RHOE) were grown air-lifted in a continuous-flow bioreactor. Mouthwashes and gels containing DNA-RNA compounds and other bioactive molecules were tested on a model of oxidative stress generated by hydrogen peroxide treatment. Epithelia viability was evaluated using a biochemical MTT-based assay and confocal microscopy; structural and ultrastructural morphology was evaluated by light microscopy and TEM. Results: DNA-RNA showed non-cytotoxic activity and effectively protected against oxidative stress, but did not help in its prevention. Gel formulations did not express adequate activity compared to the mouthwashes. Excipients played a fundamental role in enhancing or even decreasing the bioactive molecules’ effect. Conclusion: A mouthwash formulation with hydrolyzed DNA-RNA effectively protected against oxidative stress without additional enhancement by other bioactive molecules. Active compounds, such as hyaluronic acid, β-Glucan, allantoin, bisabolol, ruscogenin, and essential oils, showed a protective effect against oxidative stress, which was not synergistic with the one of DNA-RNA. Incorporation of surfactant agents showed a reduced, yet significant, cytotoxic effect.     

Effects of β-cyclodextrin-based Schiff-base Zn(II) complexes: synthesis,physicochemical characterization and their role in alleviating oxidative stress related disorder

Abstract

Two water-soluble zinc(II) complexes of β-cyclodextrin-based Schiff bases, viz., mono-6-deoxy-6-(4-(5-chloro-2-hydroxybenzylideneamino)-3,4-diaminotolune)-β-cyclodextrin (4a) and mono-6-deoxy-6-(4-(5-nitro-2-hydroxybenzylideneamino)-3,4-diaminotolune)-β-cyclodextrin (4b) have been synthesized and characterized by different analytical and spectroscopic techniques. These Zn(II) complexes were analyzed for their possible activity against oxidative stress through various biochemical methods. A detailed antioxidant profile directly associated with inflammation related carcinogenesis and several oxidative stress related disorders have been prepared with a motive to evaluate the free radical scavenging activities of the synthesized complexes. The immune cell cytotoxic properties (through MTT assay) and in vitro assay for the evaluation of their antioxidant activities against hydroxyl radical, nitric oxide, singlet oxygen, peroxynitrate and hydrogen peroxide, etc. were investigated. Obtained results clearly demonstrated the role of reactive oxygen species in various phases of oxidative stress related diseases; thus, the antioxidant and free radical scavenging capacities of the two synthesized Zn(II) complexes seem to stand in support of their beneficial effects and novelty for the immune system.