Daylight photodynamic inactivation of cattle tick Rhipicephalus microplus by porphyrins: An alternative for the ectoparasite control

The bovine tick Rhipicephalus microplus, a primary ectoparasite of veterinary concern, contributes significantly to disease transmission and reduced cattle productivity, resulting in substantial economic losses. The overuse of chemical acaricides has led to the emergence of resistant strains, posing a considerable challenge to veterinary medicine. Consequently, the development of alternative parasite control methods is essential to ensure livestock quality and enhance food safety worldwide. Our study introduces an innovative approach to photodynamic inactivation (PDI) of the bovine tick, harnessing natural daylight for a potential field application. Reproductive parameters (female and egg mass, egg production index, and larval hatch) were evaluated in engorged female ticks under photodynamic action using the hematoporphyrin (HP) and tetra-cationic porphyrins free-base meso-tetra-ruthenated (4-pyridyl) (RuTPyP) and its zinc(II) complex (ZnRuTPyP) as photosensitizers (PS). The results showed that there was no significant difference between the groups treated with tetra‑ruthenium porphyrins and the control group. However, HP exhibits a control percentage of 97.9% at a concentration of 2.5 μmol.L-1, aligning with the expected control rates achieved by conventional chemical acaricides. Photophysical and physicochemical parameters such as the number of singlet oxygen produced and lipophilicity were discussed for each PS and related to tick control percentages. Furthermore, the interaction between HP and chitin, an important macromolecule presents in the tick's cuticle, considered as the primary target tick structure during PDI was observed by the absorption and fluorescence emission spectroscopic techniques. Therefore, the results presented here extend the potential for controlling R. microplus through photodynamic inactivation while utilizing sunlight as a source of natural irradiation.

Macroporous latex biomembrane from Hancornia speciosa modulates the inflammatory process and has a debridement effect on wound healing in rats

PURPOSE

The angiogenic, osteogenic and anti-inflammatory activity of latex of Hancornia speciosa has been evidenced and indicates pharmacological potential with great applicability in the health area, especially in the wound healing process. The present work aimed to compare the effects of the H. speciosa macroporous latex biomembrane with saline on wound healing.

METHODS

Forty-three Wistar rats were submitted to excisional wound induction procedure and divided into groups according to treatment: saline (G1), and macroporous biomembrane (G2). The animals were euthanized at three, seven, 14, and 21 days after injury induction (DAI), and three animals were used for the debridement test. Morphometric, macroscopic, and microscopic analyses of general pathological processes were performed.

RESULTS

The macroporous biomembrane minimized necrosis and inflammation during the inflammatory and proliferative phases of the healing process, confirmed by the lower intensity of the crust and the debridement effect. In addition, the wounds treated with the macroporous biomembrane presented greater contraction rates in all the experimental periods analyzed.

CONCLUSIONS

The macroporous biomembrane presents angiogenic, anti-inflammatory and debridement effects, contributing to the healing process, and can be considered a potentially promising new biomaterial to be used as a dressing.

Tissue healing changes on wounds in rats after treatment with Hancornia speciosa latex in cream-gel formulation

PURPOSE

Hancornia speciosa latex has shown pharmacological potential in wound healing processes due to its angiogenic, osteogenic, and anti-inflammatory activities. The aims of this study were to carry out a cream-gel formulation with 5, 10 and 25% of H. speciosa serum latex and to evaluate its potential to stimulate the skin regeneration in rats' wounds.

METHODS

One hundred and twenty rats were divided into five groups: neutral control with saline (G1), cream-gel based on H. speciosa latex serum at 5% m/v (G2), cream-gel at 15% m/v (G3), cream-gel at 25% m/v (G4), and cream-gel (G5). The animals were euthanized at three, seven, 14 and 21 days after the injury induction, and some parameters were analyzed: wound contraction, necrosis, fibrin, polymorphonuclear and mononuclear infiltrates, fibroblast, angiogenesis, hemorrhage, and collagen.

RESULTS

The therapeutic treatment with cream-gel at 15 and 25% is beneficial in the inflammatory phase of healing processes since it increased the angiogenesis and proliferation of mononuclear infiltrations in wounds. Regarding wound contraction, the treatment with cream-gel (5 and 15%) induced a higher rate of contraction in the proliferative phase. The 15% cream-gel formulation stimulated a greater production of collagen in the injured tissues.

CONCLUSIONS

H. speciosa cream-gel is a low-cost herbal medicine which can aid in tissue repair.

Hancornia speciosa serum latex fraction: a non-allergenic biomaterial

Plant-derived products can assist in the healing process of dermal wounds. It has been demonstrated that Hancornia speciosa latex present angiogenic, osteogenic, anti-inflammatory, and antioxidant activities. Then, it could contribute to the wound healing process. However, natural products in contact with skin may cause dermatitis. The objective of this work was to evaluate the allergic and irritant potential of H. speciosa serum fraction latex using in vitro assays. The obtained results showed that the H. speciosa serum fraction latex has a slightly irritant potential and is not cytotoxic neither allergenic for human cells. Moreover, we identified a remarkable low amount of proteins in this material in comparison to Hevea brasiliensis latex. This result could explain the non-allergenic potential of H. speciosa serum fraction latex because proteins present in latex are the main responsible for allergy. This biomaterial could be used as a non-allergenic source for development of new medicines.

Immunoconjugates to increase photoinactivation of bovine alphaherpesvirus 1 in semen

Artificial insemination and in vitro embryo production are increasingly used to improve the reproductive efficiency of herds, however success of these techniques depends on the sanitary quality of the semen. Insemination centers commonly use antibiotics in their routine procedure, but they are not able against viruses. In this paper, we demonstrate a new approach for disinfecting virus in bovine semen using photoimmunoinactivation, an adaptation of the photodynamic inactivation (PDI) methodology. The photosensitizers (PSs), hematoporphyrin (HP) and zinc tetracarboxy-phthalocyanine (ZnPc) were conjugated to Immunoglobulin Y (IgY) anti-bovine alphaherpesvirus 1 (BoHV-1) and used for PDI against the BoHV-1 viruses in cell culture and compared to the unconjugated PSs. Both treatments proved to be efficient, but a significant decrease in the irradiation time required to completely eliminate the virus was observed in the samples treated with the immunoconjugates. Photophysical measurements help us to understand the coupling between PSs and IgY and the evaluated production of singlet oxygen. Following the cell culture test, the same approach was applied in semen artificially infected with BoHV-1. The immunoconjugates were also efficient for complete virus inactivation up to 5 min of irradiation and proved to be safe using several parameters of sperm viability, demonstrating the feasibility of our strategy for disinfection viruses in semen.

Optical properties and antiangiogenic activity of a chalcone derivate

Chalcones and their derivatives exhibit numerous pharmacological activities such as antibacterial, antifungal, cytotoxic, antinociceptive and anti-inflammatory. Recently, they have been assessed aiming for novel application in nonlinear optics and in the treatment of immune diseases and cancers. In this study, we investigate the optical properties of synthetic chalcona 1E,4E-1-(4-chlorophenyl)-5-(2,6,6-trimethylcyclohexen-1-yl)penta-1,4-dien-3-one (CAB7β) and its antiangiogenic potential using the chorioallantoic membrane (CAM) with the S180 sarcoma cell line. Experimental and theoretical results show intense absorption in the UVA-UVC region, which is associated with a π → π* transition with intramolecular charge transfer from the trimethyl-cyclohexen-1-yl ring to the chlorophenyl ring. Quantum chemical calculations of the first hyperpolarizability, accounting for both solvent and frequency dispersion effects, are in very good concordance with hyper-Rayleigh scattering measurements. In addition, two-photon absorption allowed band centered at 650 nm was observed. Concerning antiangiogenic activity, CAB7β causes a significant reduction in the total number, junctions, length and caliber of blood vessels stimulated by S180 cells reducing the presence of blood vessels, inflammatory cells and others elements related to angiogenic process. It is found that CAB7β is a versatile compound and a promising candidate for linear and nonlinear optical applications, in therapy against sarcoma and phototherapy.

Demetallization of Enterococcus faecalis biofilm: a preliminary study

Objectives To determine the concentration of calcium, iron, manganese and zinc ions after the application of chelator to Enterococcus faecalis biofilms. Material and Methods Fifty bovine maxillary central incisors were prepared and inoculated with E. faecalis for 60 days. The following were used as irrigation solutions: 17% EDTA (pH 3, 7 and 10), 2.5% sodium hypochlorite (NaOCl) combined with 17% EDTA (pH 3, 7 and 10), distilled water (pH 3, 7 and 10), and 2.5% NaOCl. Each solution was kept in the root canal for five minutes. Fifteen uncontaminated root canals were irrigated with 17% EDTA (pH 3, 7 and 10). Six teeth were used as bacterial control. The number of calcium, iron, manganese and zinc ions was determined using flame atomic absorption spectrometry. Mean ± standard deviation (SD) values were used for descriptive statistics. Results Calcium chelation using 17% EDTA at pH 7 was higher than at pH 3 and 10, regardless of whether bacterial biofilm was present. The highest concentration of iron occurred at pH 3 in the presence of bacterial biofilm. The highest concentration of manganese found was 2.5% NaOCl and 17% EDTA at pH 7 in the presence of bacterial biofilm. Zinc levels were not detectable. Conclusions The pH of chelating agents affected the removal of calcium, iron, and manganese ions. The concentration of iron ions in root canals with bacterial biofilm was higher after the use of 17% EDTA at pH 3 than after the use of the other solutions at all pH levels.

Evaluation of cytotoxicity and genotoxicity of Hancornia speciosa latex in Allium cepa root model

The latex obtained from Hancornia speciosa Gomes (Mangabeira tree) is widely used in traditional medicine to treat a variety of diseases, including diarrhea, ulcer, gastritis, tuberculosis, acne and warts. In this study, the cytotoxicity and genotoxicity effects of H. speciosa latex on the root meristem cells of Allium cepa were examined. Onion bulbs were exposed to different concentrations of latex and then submitted to microscopic analysis using Giemsa stain. Water was used as a negative control and sodium azide as a positive control. The results showed that, under the testing conditions, the mitotic index (MI) of the onion roots submitted to latex treatment did not differ significantly from the negative control, which suggests that the latex is not cytotoxic. Low incidence of chromosome aberrations in the cells treated with H. speciosa latex was also observed, indicating that the latex does not have genotoxic effect either. The MI and the chromosome aberration frequency responded to the latex concentration, requiring more studies to evaluate the dosage effect on genotoxicity. The results indicate that in tested concentrations H. speciosa latex is probably not harmful to human health and may be potentially used in medicine.

Intraspecific differentiation of Hancornia speciosa revealed by simple sequence repeat and random amplified polymorphic DNA markers

Hancornia speciosa, popularly known as mangabeira, is a fruit tree native to the Brazilian Cerrado that shows great economic potential, due to its multiple uses. Intraspecific classification of this species is difficult because it shows high morphological diversity. An early study of the species reported that there are six botanic varieties that differ morphologically mainly in the shapes of their leaves and flowers. Except to note the wide morphological variation and economic potential of this species, few studies have been published about the genetic diversity of mangabeira. Knowledge of the genetic variability of this species among populations would be useful for genetic conservation and breeding programs. Therefore, we tested the transferability of 12 simple sequence repeats from expressed sequence tags (EST-SSRs) from Catharanthus roseus to H. speciosa and used 10 random amplified polymorphic DNA markers to evaluate the genetic variability among botanical varieties of H. speciosa. We obtained a high transferability frequency of EST-SSR markers from C. roseus to H. speciosa (75%). However, EST-SSR markers showed low heterozygosity and locus variability (two or three alleles by locus), which suggest low genetic diversity in the mangabeira samples. The Jaccard dissimilarity index and an examination of geographic distances indicated a non-spatial structuring of the genetic variability. Our markers were unable to distinguish H. speciosa botanical varieties.

Hancornia speciosa latex for biomedical applications: physical and chemical properties, biocompatibility assessment and angiogenic activity

The latex obtained from Hancornia speciosa is used in folk medicine for treatment of several diseases, such as acne, warts, diabetes, gastritis and inflammation. In this work, we describe the biocompatibility assessment and angiogenic properties of H. speciosa latex and its potential application in medicine. The physical-chemical characterization was carried out following different methodologies (CHN elemental analyses; thermogravimetric analyses and Fourier transform infrared spectroscopy). The biocompatibility was evaluated through cytotoxicity and genotoxicity tests in fibroblast mouse cells and the angiogenic properties were evaluated using the chick chorioallantoic membrane (CAM) assay model. The physical-chemical results showed that the structure of Hancornia speciosa latex biomembrane is very similar to that of Hevea brasiliensis (commercially available product). Moreover, the cytotoxicity and genotoxicity assays showed that H. speciosa latex is biocompatible with life systems and can be a good biomaterial for medical applications. The CAM test showed the efficient ability of H. speciosa latex in neovascularization of tissues. The histological analysis was in accordance with the results obtained in the CAM assay. Our data indicate that the latex obtained from H. speciosa and eluted in water showed significant angiogenic activity without any cytotoxic or genotoxic effects on life systems. The same did not occur with H. speciosa latex stabilized with ammonia. Addition of ammonia does not have significant effects on the structure of biomembranes, but showed a smaller cell survival and a significant genotoxicity effect. This study contributes to the understanding of the potentialities of H. speciosa latex as a source of new phytomedicines.

Effect of interaction with micelles on the excited-state optical properties of zinc porphyrins and J-aggregates formation

This work reports on the photophysical properties of zinc porphyrins meso-tetrakis methylpyridiniumyl (Zn(2+)TMPyP) and meso-tetrakis sulfonatophenyl (Zn(2+)TPPS) in homogeneous aqueous solutions and in the presence of sodium dodecyl sulfate (SDS) and cetyltrimethyl ammonium bromide (CTAB) micelles. The excited-state dynamic was investigated with the Z-scan technique, UV-Vis absorption, and fluorescence spectroscopy. Photophysical parameters were obtained by analyzing the experimental data with a conventional five-energy-level diagram. The interaction of the charged side porphyrin groups with oppositely charged surfactants can reduce the electrostatic repulsion between porphyrin molecules leading to aggregation, which affected the porphyrin characteristics such as absorption cross-sections, lifetimes and quantum yields. The interaction between anionic ZnTPPS with cationic CTAB micelles induced the formation of porphyrin J-aggregates, while this effect was not observed in the interaction of ZnTMPyP with SDS micelles. This difference is, probably, due to the difference in electrostatic repulsion between the porphyrin molecules. The insights obtained by these results are important for the understanding of the photophysical behavior of porphyrins, regarding potential applications in pharmacokinetics as encapsulation of photosensitizer for drug delivery systems and in its interaction with cellular membrane.

Experimental and theoretical investigation of optical nonlinearities in (nitrovinyl)-1H-pyrazole derivative

This work reports on the optical nonlinearities of a newly synthesized pyrazole derivative, namely (E)-1-(4-chlorophenyl)-4-(2-nitrovinyl)-1H-pyrazole. The Z-scan technique with femtosecond laser pulses was used to determine the two-photon absorption (2PA) cross-section spectrum, which presents a maximum of 67 GM at 690 nm. We have combined hyper-Rayleigh scattering (HRS) experiments and second-order Møller-Plesset perturbation theory (MP2) calculations to study the first hyperpolarizability (β(HRS)). It was found that the MP2/6-311+G(d) model, taking into account solvent and dispersion effects, provides the β(HRS) value of 40×10(-30) cm(5)/esu for the compound, in good agreement with the experimental result of 45±2×10(-30) cm(5)/esu.

Effects of environment on the photophysical characteristics of mesotetrakis methylpyridiniumyl porphyrin (TMPyP)

Porphyrins are an important class of organic molecules, with interesting linear and nonlinear optical properties given mainly by their extended π-conjugation structure. Their photophysical properties can be greatly affected by the surrounding environment, which can be used to tune its final properties. Here we report on an experimental study of the photophysical properties of meso-tetrakis (methylpyridiniumyl) porphyrin (TMPyP) in aqueous and in several organic solvents and its interaction with micelles formed from negatively charged sodium dodecylsulphate (SDS), positively charged cetyl trimethyl ammonium bromide (CTAB) and neutral TRITON X-100. By using the Z-scan technique, flash-photolysis and time-resolved fluorescence techniques, we were able to evaluate the excited state dynamics of the TMPyP, and observed that the tetrapyrrole ring plays important role due to hydrogen bonds formation between nitrogen atom and water, while the side groups determine the porphyrin localization in non-aqueous micelle part.

Excited state dynamics of meso-tetra(sulphonatophenyl) metalloporphyrins

The excited state dynamics of Zn2+, Fe3+, and Mn3+ meso-tetra(sulfonatophenyl) porphyrin complexes were investigated with a Z-scan technique at 532 nm using 70 ps and 120 fs single pulses and 200 ns pulse trains of a Q-switched and mode locked laser. We determined the characteristic interconversion and intersystem crossing times, quantum yields of the excited S1 state, and S1 --> Sn and T1 --> Tn transition cross-sections. The ground state cross-sections were obtained using UV-vis absorption spectroscopy, and a five-energy-level diagram was used to yield the photophysical parameters mentioned previously.