Biochemical Composition and Antioxidant Properties of Lavandula angustifolia Miller Essential Oil are Shielded by Propolis Against UV Radiations

UV radiations are principal causes of skin cancer and aging. Suntan creams were developed to protect epidermis and derma layers against photodegradation and photooxidation. The addition of antioxidant plant extracts (i.e. essential oil) to sunscreens is habitually performed, to increase their UV protective effects and to contrast pro‐radical and cytotoxic compounds present in these solutions. According to these observations, in the present work, the alteration of chemical composition and bioactive properties of Lavandula angustifolia Miller essential oil, exposed to UV light, was investigated. UV induced a significant deterioration of lavender oil biochemical profile. Moreover, the antioxidant activity of this solution, in in vitro tests and directly on B16‐F10 melanoma cells, greatly decreased after UV treatment. Our results also showed that essential oil was shielded from UV stress by propolis addition. Even after UV treatment, bee glue highly protected lavender oil secondary metabolites from degradation and also preserved their antiradical properties, both in in vitro antioxidant assays and in cell oxidative damage evaluations. This research proposed propolis as highly efficient UV protective and antiradical additive for sunscreens, cosmetics and alimentary or pharmaceutical products containing plant extracts.     

Comparison of UV Protection Properties of Cotton Fabrics Treated with Aqueous and Methanolic Extracts of Achyranthes aspera and Alhagi maurorum Plants

UV radiations are high‐energy radiations present in sunlight that can damage human skin. Protection against these radiations becomes vital especially in those areas of the globe where UV index is quite high that makes the inhabitants more prone to dangerous effects of UV radiations. Clothing materials are good blockers of UV radiations, particularly when the fabric cover factor is high and/or the fabrics contain suitable UV‐blocking finishes. In this study, effect of application of aqueous and methanolic extracts of two different plants, i.e., Achyranthes aspera and Alhagi maurorum on UV protection properties of cotton fabric was investigated. The results showed that the fabric samples treated with extracts of both the plants have excellent UV protection properties as indicated by their ultraviolet protection factor. It was concluded that both the aqueous and methanolic plant extracts are very effective in blocking UVA and UVB radiations, when applied on cotton fabrics. The UV protection performance of Achyranthes aspera extracts was much better as compared to that of Alhagi maurorum, and methanolic extracts of both the plants outperformed the aqueous extracts in terms of UV protection.     

Near-infrared exposure changes cellular responses to ionizing radiation

Near infrared (NIR) and X-rays are radiations from different sides of the wavelength spectrum but both are used during medical treatments, as they have severe impacts on cellular processes, including metabolism, gene expression, proliferation and survival. However, both radiations differ strictly in their consequences for exposed patients: NIR effects are generally supposed to be positive, mostly ascribed to a stimulation of metabolism, whereas X-ray leads to genetic instability, an increase of reactive oxygen species (ROS) and DNA damages and finally to cellular death by apoptosis in tumor cells. Since genomic stability after X-irradiation depends on the mitochondrial metabolism, which is well known to be regulated by NIR, we analyzed the impact of NIR on cellular responses of fibroblasts, retinal progenitor cells and keratinocytes to X-radiation. Our data show that previous exposure to naturally occurring doses of nonthermal NIR combined with clinically relevant X-ray doses leads to (1) increased genomic instability, indicated by elevated ratios of mitotic catastrophes, (2) increased ROS, (3) higher amounts of X-irradiated cells entering S-phase and (4) impaired DNA double-strand break repair. Taken together, our data show tremendous effects of NIR on cellular responses to X-rays, probably affecting the results of radiotherapy after NIR exposure during cancer treatment.     

Protective Effect of Baicalin Against TLR4‐mediated UVA‐induced Skin Inflammation

UVA irradiation is known to cause photoaging via production of reactive oxygen species (ROS) and activation of inflammatory processes. Previously, we have demonstrated that baicalin, a plant‐derived flavonoid possessing both antioxidant and anti‐inflammatory activity, protects mouse keratinocytes against damage from UVB irradiation. However, the role of baicalin in vivo has not been well studied, particularly in the setting of UVA irradiation. To explore the protective effects and mechanisms of baicalin treatment in mice after UVA irradiation, mice were exposed to acute and chronic doses of UVA irradiation with or without baicalin or vehicle. Skin samples were collected for histological staining, RNA isolation, flow cytometry and protein extraction. Our results demonstrate the protective effect of baicalin against UVA‐induced oxidative damage and inflammation in mouse skin. These effects are likely mediated via the TLR4 pathway, which may serve as a target for photochemoprevention against skin inflammation.     

Effect of UVA or UVB Irradiation on Cutaneous Lipids in Films or in Solution

The barrier function of the skin is largely due to the stratum corneum which is essentially composed of lipids. Different external factors, such as UV irradiation, affect this skin layer and are responsible for a destabilization of the supramolecular organization of its constituted lipids. In this work, mass spectrometry and infrared spectroscopy are combined to study the correlation between the formation of oxidative compounds by UV irradiation and the lipid organization. Experiments were carried out on unsaturated lipids in film or solution form, exposed to UVA or UVB irradiation. UV exposure leads to the formation of oxygenated entities in the case of lipids with an unsaturated fatty acid moiety, resulting in a decrease in their packing which is greater when the lipids are in solution. The packing decrease is even greater following UVB irradiation.     

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.     

Simultaneous calibration of TLDs using the ICRU slab and photon beams

Adoption of the ICRU slab enables several dosimeters to be calibrated simultaneously. In order to allow use of identical conversion coefficients, these dosimeters should be exposed to the same irradiation conditions to within a given tolerance, account being taken of both incident and backscattered radiations. In the present study evaluation has been made of the variation in irradiation conditions for simultaneous irradiation of multiple numbers of TLDs, examination also being made of suitable gap sizes between TLDs. For simultaneous irradiation of four TLDs, a 5 cm gap is required to ensure approximate identical irradiation conditions. Approximate identical irradiation conditions have not been found possible when making simultaneous irradation of nine TLDs.     

Carbon and silicate grains in the laboratory as analogues of cosmic dust

Carbon and silicate grains are the two main components of cosmic dust. There is increasing spectroscopic evidence that their composition varies according to the cosmic environment and the experienced processing. Irradiation from ultraviolet photons and cosmic rays, as well as chemical interactions with the interstellar gas play a crucial role for grain transformation. The study of 'laboratory analogues' represents a powerful tool to better understand the nature and evolution of cosmic materials. In particular, simulations of grain processing are fundamental to outline an evolutionary pathway for interstellar particles. In the present work, we discuss the ultraviolet and infrared spectral changes induced by thermal annealing, ultraviolet irradiation, ion irradiation and hydrogen atom bombardment in carbon and silicate analogue materials. The laboratory results give the opportunity to shed light on the long-standing problems of the attribution of ultraviolet and infrared interstellar spectral features.     

Accelerated Regeneration of ATP Level after Irradiation in Human Skin Fibroblasts by Coenzyme Q10

Human skin is exposed to a number of harmful agents of which the ultraviolet (UV) component of solar radiation is most important. UV‐induced damages include direct DNA lesions as well as oxidative damage in DNA, proteins and lipids caused by reactive oxygen species (ROS). Being the main site of ROS generation in the cell, mitochondria are particularly affected by photostress. The resulting mitochondrial dysfunction may have negative effects on many essential cellular processes. To counteract these effects, coenzyme Q₁₀ (CoQ₁₀) is used as a potent therapeutic in a number of diseases. We analyzed the mitochondrial respiration profile, the mitochondrial membrane potential and cellular ATP level in skin fibroblasts after irradiation. We observed an accelerated regeneration of cellular ATP level, a decrease in mitochondrial dysfunction as well as a preservation of the mitochondrial membrane potential after irradiation in human skin fibroblasts by treatment with CoQ₁₀. We conclude that the faster regeneration of the ATP level was achieved by a preservation of mitochondrial function by the addition of CoQ₁₀ and that the protective effect of CoQ₁₀ is primarily mediated via its antioxidative function. We suggest also that it might be further dependent on a stimulation of DNA repair enzymes by CoQ₁₀.     

THE INFLUENCE OF SEMI-DEHYDRATION ON THE RESPONSE OF STREPTOCOCCUS LIQUEFACIENS TO ULTRAVIOLET LIGHT

Abstract— The effect of relative humidity on the survival and sensitivity to radiations of Streptococcus liquefaciens has been studied. The micro-organism was found to be little affected by dehydration in aerosols and its sensitivity to the lethal action of 2537 Å light to be unaffected by changes in the relative humidity at which the cells were held during irradiation. The cells were more stable to the lethal action of 3200–4000 Å, however, when they were held at 70% relative humidity than at 50 or 30% relative humidity. Mutant cells unable to liquify gelatine were induced by semi-dehydration at 50% relative humidity and their numbers were increased by concomitant irradiation with 3200–4000 Å light. This type of mutant was not observed when the cells were irradiated with 2537 Å light. Mutant cells which had a different response from that of the parent cell to the presence of oxygen in their growth medium were produced by both wavebands of light, but only when the cells were held at 50% relative humidity. It is proposed that semi-dehydration stresses the cell membrane and damages those parts of the bacterial DNA associated with the membrane. Concomitant irradiation is suggested to enhance this particular effect.     

Effect of ionizing energy on extracts of Quillaja saponaria to be used as an antimicrobial agent on irradiated edible coating for fresh strawberries

Incorporating antimicrobial compounds into edible films or coatings provides a novel way to improve the safety and shelf life of ready-to-eat foods. Diverse studies with Quillaja saponaria Mol. (popularly named quillay) extracts have demonstrated their potential as antifungal agents against phytopathogenic fungi. Crosslinking induced by ionizing radiation is an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on milk proteins. However there are few reports about the effects of γ-radiation on plant extracts. The aim of this work was to evaluate the effect of ionizing radiation (0, 5, 10, 15, 20, 25 and 35 kGy) on extracts prepared from in vitro plants of Q. saponaria to be used as antimicrobial agent in irradiated edible coating based on calcium caseinate and whey protein isolated, and also to establish the concentration of Q. saponaria extract to be added as an antifungal agent in the coating. Gamma irradiation since 15 kGy affects negatively the antimicrobial activity and metabolites composition of extract of Q. saponaria by reducing compounds of phenolic nature. Otherwise no effect on saponins profile was observed even at higher doses. It was possible to conclude that the antifungal activity of Q. saponaria extract is mainly related to phenolic compounds content. In addition, our work also shows that to obtain an efficient antifungal protection is necessary to add a minimum concentration of 6% of the extract after the coating irradiation.     

STUDIES ON THE CAPACITY OF pR IN VITRO TO PHOTOCONVERT TO THE LONG-WVELENGTH Ffr-FORM. A SURVEY FO TEN PLANT SPECIES*

Studies on the capacity of Pr in uitro to photoconvert to the long wavelength in uioo-like Pfr form were performed with extracts from 10 species. Red irradiation, immediately after extraction of crude extracts from 9 species, photoconverted Pr to long-wavelength Pfr with an absorbance maximum around 735 nm. Red irradiation of soybean extracts, however, photoconverted Pr to short-wavelength Pfr, with an absorbance maximum at 725 nm. Red irradiation given later than 1.5-2 h after extraction, to extracts of oats, pea, cucumber, radish, sunflower and soybean, photoconverted Pr to a short-wavelength Pfr species with an absorbance maximum around 725 nm. In crude extracts of barley, corn, wheat and zucchini, red irradiation, even after a long dark-incubation period at 4°C of up to 48 h, photoconverted Pr to long-wavelength Pfr with an absorbance maximum around 735 nm. After incubation at 25°C for 3 h, however, Pr from barley also photoconverted to the short-wavelength form. It is suggested that in the group exemplified by oats, Pr rapidly undergoes an alteration following extraction, which results in the loss of the capacity of Pr to photoconvert to long-wavelength Pfr. In contrast, in extracts from the group exemplified by barley, Pr is much more stable and retains the capacity to photoconvert to long-wavelength Pfr for much longer periods.     

DAMAGE BY SOLAR RADIATION AT DEFINED WAVELENGTHS. INVOLVEMENT OF INDUCIBLE REPAIR SYSTEMS

Abstract The susceptibility of bacteriophage damaged by solar-ultraviolet (UV, 290-380 nm) radiations at denned wavelengths and by radiation at a visible wavelength (405 nm) to the Weigle reactivation system induced by far-UV (254 nm) irradiation of the host cell has been studied in a repair competent strain of Escherichia coli . The sector of inducible repair diminishes with wavelength, being very small after 313 nm irradiation and absent after irradiation at longer wavelengths. However, irradiation of bacteria at wavelengths as long as 313 nm induces a bacteriophage reactivation system as effectively as radiation at 254 nm in both the repair competent and an excision deficient host cell. At longer wavelengths pre-irradiation of the repair competent host cell enhances reactivation of 254 nm irradiated bacteriophage but the reactivation is smaller and the process quite distinct from that induced in the 254-313 nm region. We conclude that, with increasing wavelength, damage induced by solar UV radiations becomes increasingly less susceptible to repair systems induced by far-UV (pyrimidine dimers) and that this type of inducible repair system is no longer induced by wavelengths longer than 313 nm.     

Gas chromatography for in situ analysis of a cometary nucleus. IV. Study of capillary column robustness for space application

As part of the development of the European Space Agency Rosetta space mission to investigate a cometary nucleus, the selection of columns dedicated to the gas chromatographic subsystem of the Cometary Sampling and Composition (COSAC) experiment was achieved. Once the space probe launched, these columns will be exposed to the harsh environmental constraints of space missions: vibrations, radiation (by photons or energetic particles), space vacuum, and large temperature range. In order to test the resistance of the flight columns and their stationary phases, the columns were exposed to these rough conditions reproduced in the laboratory. The comparison of the analytical performances of the columns, evaluated prior and after the environmental tests, demonstrated that all the columns withstand space constraints, and that their analytical properties were preserved. Therefore, all the selected capillary columns, even having porous layer or chiral stationary phases, were qualified for space exploration.     

Increased In Vitro Lysosomal Function in Oxidative Stress-Induced Cell Lines

Exposure of mammalian cells to oxidative stress alters lysosomal enzymes. Through cytochemical analysis of lysosomes with LysoTracker, we demonstrated that the number and fluorescent intensity of lysosome-like organelles in HeLa cells increased with exposure to hydrogen peroxide (H₂O₂), 6-hydroxydopamine (6-OHDA), and UVB irradiation. The lysosomes isolated from HeLa cells exposed to three oxidative stressors showed the enhanced antimicrobial activity against Escherichia coli. Further, when lysosomes that were isolated from HeLa cells exposed by oxidative stress were treated to normal HeLa cells, the viability of the HeLa cells was drastically reduced, suggesting increased in vitro lysosomal function (i.e., antimicrobial activity, apoptotic cell death). In addition, we also found that cathepsin B and D were implicated in increased in vitro lysosomal function when isolated from HeLa cells exposed by oxidative stress. Decrease in cathepsin B activity and increase in cathepsin D activity were observed in lysosomes isolated from HeLa cells after treatment with H₂O₂, 6-ODHA, or UVB, but cathepsin B and D were not the sole factors to induce cell death by in vitro lysosomal function. Therefore, these studies suggest a new approach to use lysosomes as antimicrobial agents and as new materials for treating cancer cell lines.     

Combinatorial peptide ligand libraries and plant proteomics: A winning strategy at a price

The mechanism of action and properties of a solid-phase ligand library made of hexapeptides (combinatorial peptide ligand libraries or CPLL), for capturing the “hidden proteome”, i.e. the low- and very low-abundance proteins constituting the vast majority of species in any proteome, as applied to plant tissues, are reviewed here. Plant tissues are notoriously recalcitrant to protein extraction and to proteome analysis. Firstly, rigid plant cell walls need to be mechanically disrupted to release the cell content and, in addition to their poor protein yield, plant tissues are rich in proteases and oxidative enzymes, contain phenolic compounds, starches, oils, pigments and secondary metabolites that massively contaminate protein extracts. In addition, complex matrices of polysaccharides, including large amount of anionic pectins, are present. All these species compete with the binding of proteins to the CPLL beads, impeding proper capture and identification / detection of low-abundance species. When properly pre-treated, plant tissue extracts are amenable to capture by the CPLL beads revealing thus many new species among them low-abundance proteins. Examples are given on the treatment of leaf proteins, of corn seed extracts and of exudate proteins (latex from Hevea brasiliensis). In all cases, the detection of unique gene products via CPLL capture is at least twice that of control, untreated sample.     

Effect of gamma irradiation on antiradical activity of goji berry fruits (Lycium barbarum) evaluated by EPR spectroscopy

Antiradical activity of goji berry (Lycium barbarum) was evaluated by means of electron paramagnetic resonance spectroscopy. The goji berry samples were exposed to gamma-irradiation at doses 0.05, 2 and 10 kGy. The characteristic satellite lines from cellulose radicals can prove irradiation treatment. Their intensity increase after alcohol washing and lyophilization. The fading property of satellite lines show that identification of radiation treatment is possible for 50 days. The effect of irradiation on antiradical properties of goji berry extracts was investigated by radical scavenging activity using the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH). The percentages of scavenged DPPH radicals and IC₅₀ of the extracts of goji berry before and after irradiation were calculated. The antioxidant capacity was presented in Trolox Equivalents as well. It was found out that gamma irradiation of goji berry fruits increases its antiradical activity.

     

Determination of perchlorate at parts-per-billion levels in plants by ion chromatography

A method for the analysis of perchlorate in plants was developed, based on dry weight, and applied to the analysis of plant organs, foodstuffs, and plant products. The method reduced greatly the ionic interferences in water extracts of plant materials. The high background conductivity, due to the plant matrix, was reduced sufficiently to allow quantitation of perchlorate with little or no matrix interference. Ion chromatography (IC) on a microbore AS16 anion-exchange column and a conductivity detector was used for separation and detection of perchlorate from the ionic plant extract. The extract was heated to precipitate proteins, centrifuged, exposed to alumina, and filtered through a cartridge filled with divinylbenzene to yield a water clear extract for IC analysis, even from highly colored solutions. Heating the extract and treatment with alumina reduced substantially the ionic content of the extracts without loss of perchlorate.     

Evaluation of antioxidant and cytoprotective activities of Arnica montana L. and Artemisia absinthium L. ethanolic extracts

ABSTRACT: BACKGROUND: Arnica montana L. and Artemisia absinthium L. (Asteraceae) are medicinal plants native to temperate regions of Europe, including Romania, traditionally used for treatment of skin wounds, bruises and contusions. In the present study, A. montana and A. absinthium ethanolic extracts were evaluated for their chemical composition, antioxidant activity and protective effect against H2O2-induced oxidative stress in a mouse fibroblast-like NCTC cell line. RESULTS: A. absinthium extract showed a higher antioxidant capacity than A. montana extract as Trolox equivalent antioxidant capacity, Oxygen radical absorbance capacity and 2,2-diphenyl-1-picrylhydrazyl free radical-scavenging activity, in correlation with its flavonoids and phenolic acids content. Both plant extracts had significant effects on the growth of NCTC cells in the range of 10--100 mg/L A. montana and 10--500 mg/L A. absinthium. They also protected fibroblast cells against hydrogen peroxide-induced oxidative damage, at the same doses. The best protection was observed in cell pre-treatment with 10 mg/L A. montana and 10--300 mg/L A. absinthium, respectively, as determined by Neutral red and lactate dehydrogenase assays. In addition, cell pre-treatment with plant extracts, at these concentrations, prevented morphological changes induced by hydrogen peroxide. Flow-cytometry analysis showed that pre-treatment with A. montana and A. absinthium extracts restored the proportion of cells in each phase of the cell cycle. CONCLUSIONS: A. montana and A. absinthium extracts, rich in flavonoids and phenolic acids, showed a good antioxidant activity and cytoprotective effect against oxidative damage in fibroblast-like cells. These results provide scientific support for the traditional use of A. montana and A. absinthium in treatment of skin disorders.     

Production of gamma induced reactive oxygen species and damage of DNA molecule in HaCaT cells under euoxic and hypoxic condition

The paper deals with the study of gamma radiation induced reactive oxygen species (ROS) generation in normal human keratinocytes (HaCaT) cells and quantification of subsequent damages induced on DNA molecules. The DNA damages induced in cells after gamma irradiation has been analyzed using Alkaline comet assay. The ROS produced in the cells were quantified by measuring fluorescence after loading the cells with 2′, 7′ dichlorofluorescin diacetate, a dye that is oxidized into a highly fluorescent form in the presence of peroxides. Studies reveal that in HaCaT cells radical generation occurs when exposed to ionizing radiation and it increases with dose. The induced DNA damages also increases with dose and ROS generation. The study clearly shows the importance of ROS in DNA damage induction and the cells possessing elevated levels of DNA damage after radiation exposure is due to the effect of increased levels of intracellular ROS.