Bioantioxidants

A retrospective analysis was given to the main phases in research activities dedicated to bioantioxidants with overview of the main problems and concepts addressed by researchers in the various time frames. The role of bioantioxidants in normal physiological processes and in development of pathologies was discussed. Particular emphasis was placed on the contribution from kinetic characteristics of antioxidants (reaction rate constants) into providing their biological activity, as well as to the structure-activity relationships, essential for directed search for preparations. The role of hybrid molecules that extend the spectrum of biological activities and application fields of antioxidant preparations was discussed in separate. Special consideration was given to the prospects of application of antioxidants in ultra-low doses. They exhibit both features typical for all dietary supplements in ultra-low doses and those specific to bioantioxidants, thereby complicating interpretation of the relevant findings. The inner scientific logics of development of bioantioxidant research activities were traced.     

Rapid biosynthesis of silver nanoparticles using Crotalaria verrucosa leaves against the dengue vector Aedes aegypti: what happens around? An analysis of dragonfly predatory behaviour after exposure at ultra-low doses

Aedes aegypti is a primary vector of dengue, a mosquito-borne viral disease infecting 50–100 million people every year. Here, we biosynthesised mosquitocidal silver nanoparticles (AgNP) using the aqueous leaf extract of Crotalaria verrucosa. The green synthesis of AgNP was studied by UV–vis spectroscopy, SEM, EDX and FTIR. C. verrucosa-synthesised AgNPs were toxic against A. aegypti larvae and pupae. LC₅₀ of AgNP ranged from 3.496 ppm (I instar larvae) to 17.700 ppm (pupae). Furthermore, we evaluated the predatory efficiency of dragonfly nymphs, Brachydiplax sobrina, against II and III instar larvae of A. aegypti in an aquatic environment contaminated with ultra-low doses of AgNP. Under standard laboratory conditions, predation after 24 h was 87.5% (II) and 54.7% (III). In an AgNP-contaminated environment, predation was 91 and 75.5%, respectively. Overall, C. verrucosa-synthesised AgNP could be employed at ultra-low doses to reduce larval population of dengue vectors enhancing predation rates of dragonfly nymphs.     

Green process of biomass waste derived fluorescent carbon quantum dots for biological imaging in vitro and in vivo

In the context of the circular economy, the huge amounts of biomass waste should be converted into value-added materials and energy to diminish pollution, atmospheric CO₂ levels and costly waste disposal. Biological imaging usually uses expensive and toxic chemicals e.g., organic dyes, semiconductor quantum dots, calling for safer, greener, cheaper fluorescent probes for biological imaging in vitro and in vivo. In these regards, carbon quantum dots (CQDs)-based fluorescent probes using biomass waste as a precursor may have much higher potential. Here we transformed the biomass waste of peach leaves into value-added fluorescent CQDs through a low-cost and green one-step hydrothermal process. The obtained CQDs show excitation-dependent photoluminescence properties with a fluorescence lifetime of 5.96 ns and a quantum yield of 7.71% without any passivation. In addition, the CQDs have a fine size of 1.9 nm with good hydrophilicity and high fluorescent stability over pH 4.0–11.0 range. Fluorescence imaging of in vitro cell cultures and in vivo with zebrafish show that CQDs possess ultra-low toxicity and remarkable performance for biological imaging. Even when CQDs present at a concentration as high as 500 µg/mL, the organism can still maintain more than 90% activity both in vitro and in vivo, and present bright fluorescence. The cheaper, greener, ultra-low toxicity CQDs developed in this work is a potential candidate for biological imaging in vitro and in vivo.     

高盐油藏下两性/阴离子表面活性剂协同获得油水超低界面张力

研究了在高盐油藏中, 利用两性/阴离子表面活性剂的协同效应获得油水超低界面张力的方法. 两性表面活性剂十六烷基磺基甜菜碱与高盐矿化水具有很好的相容性, 但在表面活性剂浓度为0.07%-0.39%(质量分数)范围内仅能使油水界面张力达到10^-2 mN·m^-1量级, 加入阴离子表面活性剂十二烷基硫酸钠后则可与原油达到超低界面张力. 通过探讨表面活性剂总浓度、金属离子浓度、复配比例对油水动态界面张力的影响, 发现两性/阴离子表面活性剂混合体系可以在高矿化度、低浓度和0.04%-0.37%的宽浓度范围下获得10^-5 mN·m^-1量级的超低界面张力, 并分析了两性/阴离子表面活性剂间协同获得超低界面张力的机制.     

Determination of ultra-low glass transition temperature via differential scanning calorimetry

A novel method was developed to determine the ultra-low glass transition temperature (T_g) of materials through physical blending via differential scanning calorimetry. According to the Fox equation for polymer blends, a blend of two fully compatible polymers has only one T_g. The single T_g is a function of the T_gs of the two simple polymers. Thus, the ultra-low T_g of one material can be obtained from the T_gs of another polymer and their blends. The error of T_g measurements depends on the measurement error of the T_gs for the blends and another polymer. The method was successfully applied to determine the T_gs of acetyl tributyl citrate (ATBC), tributyl citrate (TBC) and poly(ethylene glycol)s (PEG)s with different molecular weights. The T_gs for ATBC, TBC, PEG-4000 and PEG-800 were ?57.0 °C, ?62.7 °C, ?76.6 °C and ?83.1 °C, respectively. For all the samples, the standard deviation of measurements was less than 3.3 °C, and the absolute error of measurements was theoretically not more than 5.3 °C. These results indicate that this method has acceptable precision and accuracy.     

A supramolecular nanovehicle toward systematic,targeted cancer and tumor therapy

A supramolecular nanovehicle (denoted as SNV) was fabricated by encapsulating zinc phthalocyanine (ZnPc) and doxorubicin (DOX) into a copolymer (PVP-b-PAA-g-FA), so as to achieve systematic and synergistic chemotherapy-photodynamic therapy (PDT), targeted tumor imaging and therapy. The sophisticated copolymer designed in this work can load the PDT photosensitizer (ZnPc) and chemotherapy drug (DOX) simultaneously, which exhibits an excellent performance in chemotherapy-PDT targeted cancer and tumor therapy for both in vitro studies performed with HepG2 cells and in vivo tests with mice. This work provides a new drug formulation with a chemotherapy-PDT synergistic effect by virtue of the supramolecular material design, which possesses the advantages of an ultra-low drug dosage and highly-efficient in vivo targeted tumor imaging/therapy.     

Radiation hygienization of cattle and swine slurry with high energy electron beam

The research was carried out to assess the efficiency of radiation hygienization of cattle and swine slurry of different density using the high energy electron beam based on the inactivation rate of Salmonella ssp, Escherichia coli, Enterococcus spp and Ascaris suum eggs. The experiment was conducted with use of the linear electron accelerator Elektronika 10/10 in Institute of Nuclear Chemistry and Technology in Warsaw. The inoculated slurry samples underwent hygienization with high energy electron beam of 1, 3, 5, 7 and 10 kGy. Numbers of reisolated bacteria were determined according to the MPN method, using typical microbiological media. Theoretical lethal doses, D₉₀ doses and hygienization efficiency of high energy electron beam were determined. The theoretical lethal doses for all tested bacteria ranged from 3.63 to 8.84 kGy and for A. suum eggs from 4.07 to 5.83 kGy. Salmonella rods turned out to be the most sensitive and Enterococcus spp were the most resistant to electron beam hygienization. The effectiveness or radiation hygienization was lower in cattle than in swine slurry and in thick than in thin one. Also the species or even the serotype of bacteria determined the dose needed to inactivation of microorganisms.     

The effect of irradiation in the preservation of pink pepper (Schinus terebinthifolius Raddi)

Pink peppers, also known as “pimenta-rosa” and “poivre rose”, are the fruit of Schinus terebinthifolius Raddi, a species of pepper cultivated in Brazil, and have great potential for the exploration of uses. In efforts to lengthen the shelf life of this pepper, the purpose of this study was to evaluate the effect of different doses of radiation on its physical composition and color. The pink pepper samples were irradiated with doses of 0, 0.2, 0.4, 0.8 and 1.6 kGy, and the moisture, ash and lipid contents, pH and color were analyzed. The moisture content, lipid content and pH analysis indicated effects due to the irradiation (p>0.05) in which the higher doses resulted in decreases in the attribute. In contrast, there were no significant differences for the ash analysis (p<0.05) among the studied doses. The color of the pink peppers were affected by the irradiation: the parameters a^? and b^? were the most affected by the intermediate doses (0.2 and 0.8 kGy), which induced their elevation, enhancing the reddish and yellowish colors. Based on the presented data, irradiation is as an alternative preservation process for pink peppers.     

Effects of electron beam irradiation on chemical composition,antinutritional factors,ruminal degradation and in vitro protein digestibility of canola meal

The aim of the present study was to determine the impact of electron beam (EB) irradiation at doses of 15, 30 and 45 kGy on the nutritional value of canola meal. The phytic acid and total glucosinolate content of EB-irradiated canola meal decreased as irradiation doses increased (P<0.01). From in situ results, irradiation of canola meal at doses of 45 kGy decreased (P<0.05) the effective degradibility of crude protein (CP) by 14%, compared with an untreated sample. In vitro CP digestibility of EB-irradiated canola meal at doses of 15 and 30 kGy was improved (P<0.05). Electrophoresis results showed that napin and cruciferin sub-units of 30 and 45 kGy EB-irradiated canola meal were more resistant to degradation, compared with an untreated sample. Electron beam irradiation was effective in protecting CP from ruminal degradation and reducing antinutritional factors of irradiated canola meal.     

Analysis of molecular structures by homo- and hetero-nuclear J-coupled NMR in ultra-low field

The drawback of nuclear magnetic resonance (NMR) spectroscopy at ultra-low magnetic fields appears to be the lack of access to chemical information in terms of chemical shifts and homo-nuclear J-couplings. Here we report that a chemical group can be identified by the multiplet structure of the NMR spectrum in ultra-low fields if the condition of the strong hetero-nuclear J-coupling is fulfilled. Moreover we found that high-resolution ultra-low field proton-NMR spectra of liquids indeed reveal all hetero- and homo-nuclear J-couplings in terms of pairs of multiplets. This opens the door for the study of molecular structures at ultra-low magnetic fields.     

Correlation between Irradiation Treatment and Metabolite Changes in Bactrocera dorsalis (Diptera: Tephritidae) Larvae Using Solid-Phase Microextraction (SPME) Coupled with Gas Chromatography-Mass Spectrometry (GC-MS)

The metabolites produced by the larvae of Bactrocera dorsalis (Diptera: Tephritidae) exposed to different doses of irradiation were analyzed using solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS), and a metabonomic analysis method of irradiated insects based on GC-MS was established. The analysis revealed 67 peaks, of which 23 peaks were identified. The metabolites produced by larvae treated with different irradiation doses were compared by multivariate statistical analysis, and eight differential metabolites were selected. Irradiation seriously influenced the fatty acid metabolic pathway in larvae. Using the R platform combined with the method of multivariate statistical analysis, changes to metabolite production under four irradiation doses given to B. dorsalis larvae were described. Differential metabolites of B. dorsalis larvae carried chemical signatures that indicated irradiation dose, and this method is expected to provide a reference for the detection of irradiated insects.     

Suitable dose of 60Co γ-ray for mutation in Roegneria seeds

Seeds from six accessions of three species of Roegneria were radiated with ⁶⁰Co γ-ray at different doses (50, 100, 150, 200, 250, 300 and 400 Gy). Following these treatments, germination energy, germination rate, seedling height, plant height, plant survival, and seed set were observed. Plant survival was highly correlated with seedling height (R ² > 0.91, P < 0.01) and seed set (R ² > 0.82, P < 0.01). The semi-lethal dose of each accession, calculated using a ‘Multi-target single-hit’ model, ranged from 60 to 173 Gy. The most suitable absorbed doses for each accession were deduced from these data. The suitable doses for Roegneria kamoji, Roegneria ciliaris and Roegneria japonensis were 65–100 Gy, 63–150 Gy and 80–170 Gy, respectively. According to the range of suitable doses, R. kamoji (Pr87-88-353) was the most sensitive to radiation, and R. japonensis (88-89-267) was the most resistant to radiation. Suitable doses of R. ciliaris were close to that of R. kamoji (ZY1007). This research provides preliminary guidelines for radiation induced mutagenesis in Roegneria.     

Electron beam irradiation induces abnormal development and the stabilization of p53 protein of American serpentine leafminer, Liriomyza trifolii (Burgess)

The American serpentine leafminer fly, Liriomyza trifolii (Burgess), is one of the most destructive polyphagous pests worldwide. In this study, we determined electron beam doses for inhibition of normal development of the leaf miner and investigated the effect of electron beam irradiation on DNA damage and p53 stability. Eggs (0-24 h old), larvae (2nd instar), puparia (0-24 h old after pupariation) and adults (24 h after emergence) were irradiated with increasing doses of electron beam irradiation (six levels between 30 and 200 Gy). At 150 Gy, the number of adults that developed from irradiated eggs, larvae and puparia was lower than in the untreated control. Fecundity and egg hatchability decreased depending on the doses applied. Reciprocal crosses between irradiated and unirradiated flies demonstrated that males were more radiotolerant than females. Adult longevity was not affected in all stages. The levels of DNA damage in L. trifolii adults were evaluated using the alkaline comet assay. Our results indicate that electron beam irradiation increased levels of DNA damage in a dose-dependent manner. Moreover, low doses of electron beam irradiation led to the rapid appearance of p53 protein within 6 h; however, it decreased after exposure to high doses (150 Gy and 200 Gy). These results suggest that electron beam irradiation induced not only abnormal development and reproduction but also p53 stability caused by DNA damage in L. trifolii. We conclude that a minimum dose of 150 Gy should be sufficient for female sterilization of L. trifolii.     

The Effects of Different Doses of ROCK Inhibitor,Antifreeze Protein III,and Boron Added to Semen Extender on Semen Freezeability of Ankara Bucks

In the presented study, the effects of ROCK inhibitor Y-27632, antifreeze protein III, and boron at two different doses were investigated on the spermatological parameters of Ankara buck semen after freeze–thawing. Ejaculates were collected from bucks using an electroejaculator during the breeding season. The ejaculates that showed appropriate characteristics were pooled and used in the dilution and freezing of semen. The extender groups were formed by adding two different doses of three different additives (ROCK inhibitor Y-27632, 5 and 20 µM; antifreeze protein III, 1 and 4 µg/mL; boron, 0.25 and 1 mM) to the control extender. The semen was diluted with the different extenders at 35–37 °C and loaded into straws. Sperm samples frozen in liquid nitrogen vapors, following equilibration, were stored in liquid nitrogen. It was observed that extender supplementation improved post-thaw motility of Ankara buck semen after freeze–thawing. Differences were significant (p < 0.01) for 5 and 10 µM doses of ROCK inhibitor (71.82% and 74.04 % motility), as well as for 0.25 and 1 mM doses of boron (76.36% and 72.08% motility), compared to the control group (66.15% motility). With respect to the evaluation of acrosomal integrity and mitochondrial activity after freeze–thawing, although supplementation provided protection at all doses, the efficacy was not statistically significant (p > 0.05). It was observed that DNA damage was improved by antifreeze protein III at 1 µg/mL (1.23% ± 0.23%) and by boron at all doses (0.25 mM: 1.83% and 1 mM: 1.18%) compared to the control group (3.37%) (p < 0.01), following the thawing process. In the present study, it was determined that some additives added to the extender provided significant improvements in buck spermatozoa motility and DNA damage after thawing.     

Chi@HMPB@CBD nanocomplexes for laser-assisted therapy of MRSA-infected cutaneous wounds in normal and MKR diabetic mice

The emergence and spreading of methicillin-resistant Staphylococcus aureus (MRSA) have become one of the main reasons for the surgical failure even for the death. Thus, there is an urgent need to develop efficient antimicrobial alternatives for eradicating it so as to improve the therapy efficiency of related diseases. Although the synthesized metal nanoparticles showed the MRSA-killing function in vitro, their biosafety in vivo application is still in controversy due to the potential toxicity and induced multidrug resistance. Recently, plant natural compounds with high antibacterial activity and special mechanisms different from antibiotics have attracted wide interest for developing new anti-MRSA regents. In this work, new nanocomplexes of Chi@HMPB@CBD based on natural compounds of cannabidiol (CBD) and chitosan (Chi) were designed for eradicating MRSA. In vitro results demonstrate that Chi@HMPB@CBD NPs plus laser irradiation can efficiently kill MRSA by inducing bacterial surface perforation, content leakage, ROS production, and ATP reduction. In vivo results show that the combination of Chi@HMPB@CBD NPs plus laser can effectively remove bacteria and accelerate wound healing of MRSA-infected normal and diabetes mellitus mice by up-regulating VEGF and CD31. Moreover, Chi@HMPB@CBD NPs possessing excellent biocompatibility and ultra-low toxicity in vitro significantly delayed the time for multidrug-resistance induction, comparing with silver nanoparticles. In our point, the “green therapeutics” against MRSA show great potential in clinical application.     

High performance dual frequency liquid crystal compounds and mixture for operation at elevated temperature

Dual frequency liquid crystal (DFLC) compounds with high birefringence and ultra-low crossover frequency have been developed. The long conjugated rigid core structure gives these compounds a high birefringence (0.3–0.4) and ultra-low Debye relaxation frequency. Using these compounds we have formulated a new DFLC mixture, designated UCF–02, for operation at elevated temperatures. The birefringence of the mixture is greater than 0.3 at 25°C and λ = 633 nm. Their initial ultra-low crossover frequency allows them to be used at elevated temperatures and significantly improves their utility.     

阴阳离子表面活性剂混合体系在克拉玛依油田中获得超低界面张力

利用阴阳离子表面活性剂复配技术,在克拉玛依油田实际油水体系中获得了超低界面张力.通过添加非离子保护剂的第三组分,阴阳离子表面活性剂混合体系在克拉玛依油田回注水体系中的溶解度大大提高.确定了相关体系能够获得超低界面张力的表面活性剂的浓度和混合的比例范围,在克拉玛依油田的多个实际油水体系中获得了具有较大复配比例和较低表面活性剂浓度的实际配方,其中部分体系油水界面张力可接近10-4mN·m-1.同时,这类阴阳离子表面活性剂混合体系具有很好的抗吸附能力,在石英砂吸附72 h后体系依然呈现优良的超低界面张力.     

Effect of gamma irradiation on the antimicrobial and free radical scavenging activities of Glycyrrhiza glabra root

The efficacy of gamma irradiation as a method of decontamination for food and herbal materials is well established. In the present study, Glycyrrhiza glabra roots were irradiated at doses 5, 10, 15, 20 and 25 kGy in a cobalt-60 irradiator. The irradiated and un-irradiated control samples were evaluated for phenolic contents, antimicrobial activities and DPPH scavenging properties. The result of the present study showed that radiation treatment up to 20 kGy does not affect the antifungal and antibacterial activity of the plant. While sample irradiated at 25 kGy does showed changes in the antibacterial activity against some selected pathogens. No significant differences in the phenolic contents were observed for control and samples irradiated at 5, 10 and 15 kGy radiation doses. However, phenolic contents increased in samples treated with 20 and 25 kGy doses. The DPPH scavenging activity significantly (p<0.05) increased in all irradiated samples of the plant.     

Evaluation of microbial loads,physical characteristics,chemical constituents and biological properties of radiation processed Fagonia arabica

Whole plant of Fagonia arabica with 3 different particle sizes (30, 50 and 70 mesh) were exposed to gamma radiation doses of 1–10 kGy from a Cobalt 60 source. A series of tests was performed in order to check the feasibility of irradiation processing of the plant. The applied radiation doses did not affect (P<0.05) pH and antimicrobial activities of the plant. The total weight of the dry extracts in methanol as well as water was found increased with irradiation. The irradiated samples showed significant increase in phenolic content and free radical scavenging activity using DPPH. Shortly after irradiation (on the day of radiation treatment) high amounts of free radicals were detected in the irradiated plant samples and the chemiluminescence measurements were generally found to be dose dependent. Maximum luminescence intensity was observed in case of samples with mesh size of 30 for all the radiation doses applied. After a period of one month the chemiluminescence signals of the irradiated samples approximated those of the controls. The study suggests that gamma irradiation treatment is effective for quality improvement and enhances certain beneficial biological properties of the treated materials.     

Evaluation of the safety and antioxidant activities of Crocus sativus and Propolis ethanolic extracts

The possible toxicological effects and in vitro antioxidant activity of the ethanolic extracts of Crocus sativus and Propolis were investigated. Both extracts did not cause any mortalities or signs of toxicity in mice when administered orally at doses up to 5 g/kg b.wt. In the sub-chronic study; the tested extracts did not produce any significant change in liver and kidney functions of rats, following oral administration for 8 successive weeks at doses of 500 mg/kg b.wt. of each. Propolis showed remarkable in vitro antioxidant activity at concentrations of (40–100 mg/ml). In contrast, the ethanolic extract of C. sativus ethanolic extract showed weak antioxidant activity in concentrations of (1–10 mg/ml) while at concentrations of (20–100 mg/ml) failed to exhibit any antioxidant activity. It was concluded that: both extracts were non-toxic, as they did not cause any mortalities or signs of toxicity in mice when administered orally at doses up to 5 g/kg b.wt. Daily oral administration of C. sativus, Propolis ethanolic extracts alone or in combination for 8 successive weeks to rats was quiet safe and didn't cause any toxic changes in liver and kidney. Antioxidant study showed that Propolis ethanolic extract was a more potent antioxidant than C. sativus extract.