The coronavirus disease 2019 (COVID-19) pandemics is a challenge without precedent for the modern science. Acute Respiratory Discomfort Syndrome (ARDS) is the most common immunopathological event in ...SARS-CoV-2, SARS-CoV, and MERS-CoV infections. Fast lung deterioration results of cytokine storm determined by a robust immunological response leading to ARDS and multiple organ failure. Here, we show cysteine protease Cathepsin L (CatL) involvement with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and COVID-19 from different points of view. CatL is a lysosomal enzyme that participates in numerous physiological processes, including apoptosis, antigen processing, and extracellular matrix remodeling. CatL is implicated in pathological conditions like invasion and metastasis of tumors, inflammatory status, atherosclerosis, renal disease, diabetes, bone diseases, viral infection, and other diseases. CatL expression is up-regulated during chronic inflammation and is involved in degrading extracellular matrix, an important process for SARS-CoV-2 to enter host cells. In addition, CatL is probably involved in processing SARS-CoV-2 spike protein. As its inhibition is detrimental to SARS-CoV-2 infection and possibly exit from cells during late stages of infection, CatL could have been considered a valuable therapeutic target. Therefore, we describe here some drugs already in the market with potential CatL inhibiting capacity that could be used to treat COVID-19 patients. In addition, we discuss the possible role of host genetics in the etiology and spreading of the disease.
DC. is a plant species from the Asteraceae family that is endemic to Brazil. Despite the great importance of
genus, no study has been carried out regarding either the phytochemical composition of
or ...the evaluation of its larvicidal potential. Considering the intrinsic immiscibility of essential oils, this study shows larvicidal nanoemulsions containing the
phytochemically characterized essential oil and its main constituent against
. The major compound found was d-limonene (25.7%). The essential oil inhibited the acetylcholinesterase, one of the main targets of insecticides. The required hydrophile-lipophile balance of both nanoemulsions was 15.0. The mean droplet sizes were around 90.0 nm, and no major alterations were observed after 24 h of preparation for both formulations. After 48 h of treatment, the estimated LC
values were 118.94 μg mL
and 81.19 μg mL
for
essential oil and d-limonene nanoemulsions, respectively. Morphological alterations evidenced by scanning electron micrography were observed on the larvae treated with the d-limonene nanoemulsion. This paper demonstrated a simple and ecofriendly method for obtaining
essential oil and d-limonene aqueous nanoemulsions by a non-heating and solvent-free method, as promising alternatives for
control.
Pectis elongata is found in the northern and northeastern regions of Brazil. It is considered a lemongrass due to its citric scent. The remarkable citral content and the wide antimicrobial properties ...and bioactive features of this terpene make this essential oil (EO) eligible for several industrial purposes, especially in cosmetics and phytotherapics. However, to address the problems regarding citral solubility, nano-emulsification is considered a promising strategy thanks to its improved dispersability. Thus, in this paper we propose a low-energy approach for the development of citral-based nano-emulsions prepared with P. elongata EO. The plant was hydrodistillated to produce the EO, which was characterized with a gas chromatograph coupled to mass spectrometry. The nano-emulsion prepared by a non-heated water titrating (low-energy) method was composed of 5% (w/w) EO, 5% (w/w) non-ionic surfactants and 90% (w/w) deionized water and was analyzed by dynamic light scattering. Levels of citral of around 90% (neral:geranial—4:5) were detected in the EO and no major alteration in the ratio of citral was observed after the nano-emulsification. The nano-emulsion was stable until the 14th day (size around 115 nm and polydispersity index around 0.2) and no major alteration in droplet size was observed within 30 days of storage. Understanding the droplet size distribution as a function of time and correlating it to concepts of compositional ripening, as opposing forces to the conventional Ostwald ripening destabilization mechanism, may open interesting approaches for further industrial application of novel, low-energy, ecofriendly approaches to high citral essential oil-based nano-emulsions based on lemongrass plants.
Pterodon emarginatus Vogel is a Brazilian species that belongs to the family Fabaceae, popularly known as sucupira. Its oil has several biological activities, including potent larvicidal property ...against Aedes aegypti. This insect is the vector of dengue, a tropical disease that has been considered a critical health problem in developing countries, such as Brazil. Most of dengue control methods involve larvicidal agents suspended or diluted in water and making active lipophilic natural products available is therefore considered a technological challenge. In this context, nanoemulsions appear as viable alternatives to solve this major problem. The present study describes the development of a novel nanoemulsion with larvicidal activity against A. aegypti along with the required Hydrophile Lipophile Balance determination of this oil. It was suggested that the mechanism of action might involve reversible inhibition of acetylcholinesterase and our results also suggest that the P. emarginatus nanoemulsion is not toxic for mammals. Thus, it contributes significantly to alternative integrative practices of dengue control, as well as to develop sucupira based nanoproducts for application in aqueous media.
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•The Brazilian Sucupira tree oil has a wide range of biological properties.•SO-NE as a potential strategy for the cutaneous leishmaniasis treatment in vivo.•The formulation SO-NE was ...able to reduce lesions caused by L. (L.) amazonensis.•SO-NE and antimoniate combination altered cytokine levels related to leishmaniasis.
Cutaneous leishmaniasis (CL) is a neglected tropical skin disease caused by the protozoan genus Leishmania. The treatment is restricted to a handful number of drugs that exhibit toxic effects, limited efficacy, and drug resistance. Additionally, developing an effective topical treatment is still an enormous unmet medical challenge. Natural oils, e.g. the oleoresin from P. emarginatus fruits (SO), contain various bioactive molecules, especially terpenoid compounds such as diterpenes and sesquiterpenes. However, its use in topical formulations can be impaired due to the natural barrier of the skin for low water solubility compounds. Nanoemulsions (NE) are drug delivery systems able to increase penetration of lipophilic compounds throughout the skin, improving their topical effect. In this context, we propose the use of SO-containing NE (SO-NE) for CL treatment. The SO-NE was produced by a low energy method and presented suitable physicochemical characteristic: average diameter and polydispersity index lower than 180 nm and 0.2, respectively. Leishmania (Leishmania) amazonensis-infected BALB/c mice were given topical doses of SO or SO-NE. The topical use of a combination of SO-NE and intraperitoneal meglumine antimoniate reduced lesion size by 41 % and tissue regeneration was proven by histopathological analyses. In addition, a reduction in the parasitic load and decreased in the level of IFN-γ in the lesion may be associated, as well as a lower level of the cytokine IL-10 may be associated with a less intense inflammatory process. The present study suggests that SO-NE in combination meglumine antimoniate represents a promising alternative for the topical treatment of CL caused by L. (L.) amazonensis.
Mosquitoes can be vectors of pathogens and transmit diseases to both animals and humans. Species of the genus Culex are part of the cycle of neglected diseases, especially Culex quinquefasciatus, ...which is an anthropophilic vector of lymphatic filariasis. Natural products can be an alternative to synthetic insecticides for vector control; however, the main issue is the poor water availability of some compounds from plant origin. In this context, nanoemulsions are kinetic stable delivery systems of great interest for lipophilic substances. The objective of this study was to investigate the larvicidal activity of the Hyptis suaveolens essential oil nanoemulsion on Cx. quinquefasciatus. The essential oil showed a predominance of monoterpenes with retention time (RT) lower than 15 min. The average size diameter of the emulsions (sorbitan monooleate/polysorbate 20) was ≤ 200 nm. The nanoemulsion showed high larvicidal activity in concentrations of 250 and 125 ppm. CL50 values were 102.41 (77.5253−149.14) ppm and 70.8105 (44.5282−109.811) ppm after 24 and 48 h, respectively. The mortality rate in the surfactant control was lower than 9%. Scanning micrograph images showed changes in the larvae’s integument. This study achieved an active nanoemulsion on Cx. quinquefasciatus through a low-energy-input technique and without using potentially toxic organic solvents. Therefore, it expands the scope of possible applications of H. suaveolens essential oil in the production of high-added-value nanosystems for tropical disease vector control.
Metal nanoparticles are a promising approach for the development of new antimicrobial systems. Silver nanoparticles (AgNP) have a significant antibacterial activity through bacterial surface ...adsorption and oxidative stress induction, as indicated by recent observations. This research aimed to use endophytic fungi from the genus
Trichoderma
spp. isolated from the
Bertholletia excelsa
(Brazil-nut) seeds and the soil to biosynthesize AgNPs and also test their antibacterial activity. The use of these fungi for this purpose not only valorizes the Amazon biodiversity but it also uses cleaner and cheaper processes, being part of the Green Chemistry concept. The particles were analyzed through Ultraviolet–Visible Spectroscopy and ZetaSizer and the band of absorption at 420 nm was analyzed through Localized Surface Plasmon Resonance. After characterization, the AgNP were tested for antibacterial activity against several bacterial strains, when it was observed that their antibacterial activity was superior in Gram-negative bacteria.
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•Peel’s extract has antioxidant potential and high phenolic content.•It is possible to obtain nano-dispersed systems with this complex material by low energy methods.•Polysorbate 85 optimizes the ...development of the nanodispersions.•This novel nanobiotechnology product may decrease the economic costs of the process.•The green and ecofriendly method is in accordance with sustainable concepts.
Jaboticaba (Myrciaria cauliflora) is considered a “super fruit” due to its remarkable phenolic content and antioxidant capacity. Despite the great potential of its peels, to our knowledge the investigation of novel nanostructured systems with this natural raw material, still considered an industrial residue, is scarce. The present study aimed to obtain nanodispersions with its peel’s extract through a low energy method. Antioxidant assays were performed, showing positive results for DPPH (IC50 = 0.89 μg/mL) and FRAP (225.53 μmol equivalent ferrous sulphate/g). The chemical characterization in terms of flavonoids (2.56%) and total monomeric anthocyanins (0.80%) contents were also performed. Overall, the nanodispersion prepared with the non-ionic surfactant polysorbate 85 and the hydroalcoholic extract standardized in ellagic acid (129 µg/mL) presented the best properties regarding particle size distribution and zeta potential. Thus, it opens perspectives for the generation of novel food-grade nanodispersions through an ecofriendly approach that is in accordance to sustainable concepts.
Schistosomiasis is a neglected disease transmitted through contaminated water in populations with low basic sanitation. The World Health Organization recommends controlling the intermediate host ...snails of the Biomphalaria genus with the molluscicide niclosamide. This work aims to evaluate the biocidal potential of the nanoemulsion prepared with the essential oil of Ocotea indecora leaves for the control of the mollusk Biomphalaria glabrata, intermediate host of the Schistosoma mansoni, the etiologic agent of schistosomiasis.
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•The Ocotea indecora essential oil presented sesquirosefuran as a predominant compound.•The essential oil nanoemulsion showed a prominent molluscicidal effect.•The nanoemulsion was 3x more effective than the essential oil.
Nanotechnology has emerged as a promising area for innovative products, including insecticides. Dengue is a tropical disease which is considered a critical health problem in developing countries, due ...to negative impacts to the environment caused by synthetic chemicals used for vector control (Aedes aegypti). Thus, developing of natural products based insecticidal are considered very promising. On this context, the aim of the present study was to obtain an O/W nanoemulsion containing Rosmarinus officinalis L., Lamiaceae, essential oil and evaluate its larvicidal activity against A. aegypti. Low energy method was employed, allowing achievement of small droplets. The nanoemulsion also presented low polydispersity and mean droplet below 200nm, even after 30 days of storage. Potential mortality levels were observed after 24h (80±10%) and 48h (90±10%) in A. aegypti larvae at final concentration of 250ppm, related to R. officinalis essential oil. This study contributes to nanobiotechnology of natural products, presenting a potential larvicidal nanoemulsion prepared with R. officinalis essential oil. Moreover, nanoemulsion production involved a non-heating procedure, describing easy technique which may be useful for integrative control programs.
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