Photon spectra effects tested on the vegetal model Allium cepa.

The use of artificial light sources in plants is considered a type of photobiomodulation (PBM), a trend in agriculture and food industries, aiming at decontamination, pest control, and increased production yield. However, literature lacks a broader assessment to address the effects of photon light spectra on plant characteristics. Here, we aimed to describe the effects of visible light, infrared, and ultraviolet light upon Allium cepa, a known bioindicator, under various light doses. Samples irradiated under visible and infrared light did not show cytotoxicity, genotoxicity, or mutagenicity in any of the evaluated doses. Light induction at 460 and 635 nm significantly stimulated root development of the test organism. In contrast, 254 nm irradiation proved to be cytotoxic, genotoxic, and mutagenic. This work reveals and quantifies the spectral response of A. cepa seeds, suggesting that it can be proposed as a model for future research on mechanisms of PBM in plants.

Natural versus synthetic curcuminoids as photosensitizers: Photobleaching and antimicrobial photodynamic therapy evaluation.

Antimicrobial photodynamic therapy (aPDT) has been studied as an alternative to combat bacterial resistance to the commonly used antibiotics. aPDT requires the use of a photosensitizer and curcumin is one of the more promising, though the usage of natural curcumin can be inconsistent in certain biomedical uses due to differences in soil condition and turmeric age, besides a large quantity of the plant is necessary to obtain useful amounts of the actual molecule. As such, a synthetic analogue is preferred as it is pure, and its components are better characterized. The present work studied photophysical differences in both natural and synthetic curcumin using photobleaching experiments and searched for whether differences existed in aPDT studies against Staphylococcus aureus. The results showed a faster O2 consumption and a singlet oxygen's generation rate lower by the synthetic curcumin, in comparison with the natural derivative. However, no statistical difference was observed when inactivating S. aureus and these results were following a concentration-based pattern. Thus, the use of synthetic curcumin is indicated, as it can be obtained in controlled amounts and with less environmental impact. Although there are small changes in a photophysical context comparing natural versus synthetic curcumins, we did not observe statistical differences in the photoinactivation of S.aureus bacteria, and reproducibility in biomedical contexts is better achieved with the synthetic analogue.

Buriti (Mauritia flexuosa L. f.): An Amazonian fruit with potential health benefits.

The Amazon region has a significant biodiversity composed of several fruits with health benefits and distinguished potential for technological application and development of novel products. Buriti (Mauritia flexuosa) is one of the main Amazonian fruits with expressive nutraceutical properties. For this reason, this review aims to elucidate the current state of knowledge on buriti, providing information on its bioactive compounds, nutraceutical, and health potential for both technological and economic development especially in food and pharmaceutical areas. Different parts of buriti are important sources of carotenoids, fatty acids, phenolic compounds, and fibers. Antioxidant, antimicrobial, prebiotic, anti-diabetes, and anti-cancer properties have also been reported. In addition, the buriti oil presents a synergistic effect with antibiotics and it has been also an alternative to artificial dyes. However, there is a lack of information about the in vivo evaluation of the buriti's bioactive compounds providing a clearer elucidation on its biological potential, toxicity information and mechanisms of action. Proper sensory methods and the relationship between sensory quality and consumer perception are also needed to extend the possibility of developing new products. Finally, the use of non-thermal techniques is encouraged to improve the bioavailability of nutraceutical compounds and potentiate their action on human health.

Follow-up of pressure ulcer treatment with photodynamic therapy, low level laser therapy and cellulose membrane.

OBJECTIVE: A pressure ulcer (PU) is an area of tissue trauma caused by continuous and prolonged pressure, often associated with hospitalised patients immobilised due to neurological problems, negatively affecting their quality of life, and burdening the public budget. The aim of this study was to report the follow-up, for 45 weeks, of three patients with neurological lesions due to trauma who subsequently developed PUs, and who were treated with a combination of photodynamic therapy (PDT), low level laser therapy (LLLT) and cellulose membrane (CM). METHOD: PDT was mediated by the photosensitiser curcumin on a 1.5% emulsion base. Blue LED light at 450 nm was delivered continuously for 12 minutes at an irradiance of 30mW/cm2 and total energy delivered to the tissue was 22J/cm2. LLLT was performed with 660 nm laser, punctuated and continuous, twice a week with parameters: spot size 0.04cm2, power of 40mW, 10 seconds per point, fluence of 10J/cm2 and irradiance of 1000mW/cm2. RESULTS: All PUs had a significant reduction (range: 95.2-100%) of their area after 45 weeks of follow-up and two PUs had complete healing at 20 weeks and 30 weeks. All of the PUs showed a reduction in contamination with the PDT treatments in different proportions. CONCLUSION: From the results obtained, we conclude that the combination of PDT, LLLT and CM is a promising treatment for PU healing.

Evolution of surviving Streptoccocus pyogenes from pharyngotonsillitis patients submit to multiple cycles of antimicrobial photodynamic therapy.

It is estimated over 600 million pharyngotonsillitis (PT) cases worldwide per year and 30% of this total are caused by Streptococcus pyogenes with standard antibiotic treatment. Antimicrobial Photodynamic Therapy (aPDT) has been studied for the clinical research in infectious diseases. The study aim was to analyze the evolution of aPDT on inactivation of clinical strains of multiple cycles. S. pyogenes and clinical strains isolated from patients with PT were incubated with curcumin in formulation (2.25 mg/ml) and irradiated at 450 nm in Light fluence rates. A mortality was a measure of the counting colony forming units per milliliter (CFU/ml) surviving. Parameters of bacterial biofilm formation, uptake of photosensitizer (PS) and efficacy of antibiotics on survival of bacteria of each cycle were tested. The bacteria profile remains unchanged between 10 aPDT cycles was observed. The bacterial colony survival presented a reduction in capacity to form biofilm due adhesion of strains and PS uptake rate. The antibiotic remained efficient after aPDT cycles. Our in vitro results suggested a low-level of development of PDT resistance, however a decrease of photosensitizer uptake was observed. Furthermore, there is no cross effect on aPDT cycles and the first application of antibiotics.

Curcumin in formulations against Aedes aegypti: Mode of action, photolarvicidal and ovicidal activity.

Combating the Aedes aegypti vector is still the key to control the transmission of many arboviruses, such as Dengue, Zika, and Chikungunya. As few products are efficient for Aedes aegypti control, the search for new strategies have become pivotal., t Substances with photodynamic activity, such as curcumin and their formulations, are strongly encouraged, due to their multi-target mechanism of action. In this study, we evaluated the photolarvicidal and ovicidal activity of curcumin in the presence of sucrose (named SC) and d-mannitol (named DMC). To support the understanding of the larvicidal action of these formulations, Raman micro-spectroscopy was employed. We also studied the morphological changes in Danio rerio (Zebrafish) gills, a non-target organism, and demonstrate that this is an environmentally friendly approach. Both SC and DMC presented a high photo-larvicidal potential. DMC showed the highest larval mortality, with LC50-24h values between 0.01 and 0.02 mg.L-1. DMC also significantly decreased egg hatchability, reaching a hatching rate of 10 % at 100 mg.L-1. The analysis of molecular mechanisms via Raman micro-spectroscopy showed that DMC is highly permeable to the peritrophic membrane of the larva, causing irreversible damage to the simple columnar epithelium of the digestive tube. Histological changes found in the D. rerio gills were of minimal or moderate pathological importance, indicating an adaptive trait rather than detrimental characteristics. These findings indicate that curcumin in sugar formulations is highly efficient, especially DMC, proving it to be a promising and safe alternative to control Aedes mosquitoes. Moreover, Raman micro-spectroscopy demonstrated high potential as an analytical technique to understand the mechanism of action of larvicides.

Total mouth photodynamic therapy mediated by blue led and curcumin in individuals with AIDS.

OBJECTIVES: To test the effectiveness of an efficient therapeutic protocol for the total mouth antimicrobial photodynamic therapy (aPDT) mediated by 450 nm blue LED associated with curcumin in individuals with AIDS. METHODS: Patients were selected by exclusion criteria and randomly distributed in groups to test the effectiveness of antimicrobial aPDT with curcumin 0.75 mg/mL associated with the blue LED (67 mW/cm2, 20.1 J/cm2). Before and after the treatments, samples were collected from the saliva being processed in duplicate in selective culture media. The colonies were counted and the results obtained in log10 CFU/mL were statistically tested (T-paired statistical test, 5%). RESULTS: The log10 CFU/mL of Streptococcus spp., Staphylococcus spp., and total count of microorganisms showed statistically significant (p = 0.023; p = 0.001 and p = 0.017, respectively) reduction after treatment in patients with aPDT. CONCLUSION: aPDT was effective in reducing Streptococcusspp. in addition to reducing Staphylococcusspp., enterobacteria and the total count of microorganisms when considering the numbers of TCD4 and TCD8 lymphocytes. The aPDT in the studied protocol was able to control clinically important intraoral microorganisms for AIDS patients, both those with TCD4 lymphocytes above or below 25% of normal and those with TCD8 lymphocytes above 25% of normal.

Optimization for microbial incorporation and efficiency of photodynamic therapy using variation on curcumin formulation.

INTRODUCTION: A mixture of curcuminoids: curcumin, desmethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC) are named natural curcumin. It is a lipophilic photosensitizer (PS) highly soluble in an organic solvent such as dimethyl sulfoxide (DMSO). Curcumin is a PS used for microbial inactivation using photodynamic action. However, this solvent has high cytotoxicity and is unavailable in formulations for clinical use. This study aimed to investigate the interactions of curcuminoids syrup with Streptococcus sp., a gram-positive coccus and one of the major pharyngeal pathogens, responsible for diseases such as pharyngitis. METHODS: Bacteria were incubated with curcuminoids (natural curcumin, synthetic, DMC, BDMC) at 37 °C in formulations: 1) syrup (water + sucrose) 2) solution alcohol + DMSO. Was centrifuged, and the supernatant collected for absorbance analysis. The results obtained correlating the absorbance with the supernatant to the absorbance of the default concentration. A study of microbial metabolism by growth curve was carried out to justify the result. RESULTS: The incorporation of curcumin in syrup is superior to alcohol/DMSO solution by microorganisms. Curcumin incorporation by S. mutans, S. pyogenes, isolated bacteria was 24, 26, 27 % in syrup and 10, 13, 5 % in alcohol/DMSO, respectively. Also, the presence of carbohydrate in a solution can activate the bacterial metabolism, getting better uptake results and photodynamic inactivation to natural curcumin and DMC. Such finds care optimizes the use of curcumin without complications generated by the solvent.

Manual Operated Ultraviolet Surface Decontamination for Healthcare Environments.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of a new handheld equipment based on a mercury low-pressure vapor lamp. The Surface UV® device was tested in Staphylococcus aureus, Streptococcus mutans, Streptococcus pneumoniae, two strains of Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and other clinical microorganisms isolated from different surfaces of a public health hospital. BACKGROUND DATA: The incidence of hospital infections has increased in recent years. Despite the variety of available chemicals to reduce the microorganisms, the search for antimicrobial agents and the characterization of novel targets are a continued need. Also, the minimization of chemical procedures is a constant need, and the use of ultraviolet (UV) light as a germicidal device for microorganisms' inactivation has been an alternative and one possible approach for the reduction of contamination. MATERIALS AND METHODS: The in vitro decontamination was performed by application of Surface UV in different species of microorganisms (study 1). The surface decontamination was carried out by application of Surface UV on each surface of hospital environment (study 2). The device presents ultraviolet C (UV-C) light at 254 nm and produces an irradiance of 13 mW/cm2 at a distance of 1 cm of the surfaces. The light dose was 0.78 J/cm2 for 60 sec of application in both studies. RESULTS: The results for in vitro decontamination indicated a log10 reduction factor of 6.5 for S. aureus, 6.7 for S. mutans, 6.2 for S. pneumoniae, 5.4 for E. coli, 5.2 for E. coli (ATCC 8739), 5.4 for P. aeruginosa, and 6.7 for C. albicans. The hospital level of microorganisms decreases more by 75% after the procedure. CONCLUSIONS: The study highlights the development and successful application of a new portable device that can reduce the risk of contamination in health settings. Our results suggest that Surface UV is efficient and may be an alternative decontamination method.