Nanotechnology as a Tool for Optimizing Topical Photoprotective Formulations Containing Buriti Oil (Mauritia flexuosa) and Dry Aloe vera Extracts: Stability and Cytotoxicity Evaluations.

Human beings are actively exposed to ultraviolet (UV) radiation, which is associated with skin cancer. This has encouraged the continuous search for more effective and safer photoprotective formulations. Along with the application of traditional organic sunscreens, there is a growing interest in "green products" containing natural compounds such as plant extracts and oils. This trend is combined with the use of nanotechnology as a tool for optimizing the vehicles of such compounds. Nanoemulsions (NEs) are suitable for the encapsulation of natural compounds, which improves topical treatment. Therefore, we have developed oil-in-water (O/W) nanoemulsions containing 3% buriti oil (BO), incorporated in a 10% vegetal extract of Aloe vera (AV) by means of ultrasonic processing to improve the chemical characteristics of this component and, consequently, its efficacy and safety in pharmaceutical and cosmetic formulations. The composition of the formulation was initially defined in a preliminary study on surfactants where the concentrations of Tween® 80 and Span® 20 were evaluated in relation to particle size and the polydispersity index (PDI). The nanoemulsion was prepared and then chemical sunscreens were incorporated with the aim of developing a sunscreen nanoemulsion called NE-A19. This nanoemulsion was found to be the best formulation due to its stability, droplet size (146.80 ± 2.74), and PDI (0.302 ± 0.088), with a monomodal size distribution. The stability was evaluated over 90 days and showed a low growth in particle size at the end of the study. NE-A19 exhibited good viscosity and organoleptic properties, in addition to an occlusion factor indicating an interesting and higher water holding capacity when compared with a NE without AV (p < 0.05). The in vitro efficacy and safety studies of NE-19A were promising. Its average in vitro sun protection factor value was 49, with a critical wavelength (λc) of 369.7 nm, satisfactory UVA protection, and a UVA/UVB ratio of 0.40, indicating broad spectrum protection against UVA and UVB radiation. Furthermore, NE-19A displayed a good safety profile in dermal keratinocytes. It can be concluded that NE-19A is a promising formulation for carrying natural products, such as buriti oil and AV, associated with synthetic filters in lower concentrations.

Constituents of buriti oil (Mauritia flexuosa L.) like inhibitors of the SARS-Coronavirus main peptidase: an investigation by docking and molecular dynamics.

Statistics show alarming numbers of infected and killed in the world, caused by the Covid-19 pandemic, which still doesn't have a specific treatment and effective in combating all efforts to seek treatments and medications against this disease. Natural products are of relevant interest in the search for new drugs. Thus, Buriti oil (Mauritia flexuosa L.) is a natural product extracted from the fruit of the palm and is quite common in the legal Amazon region, Brazil. In the present work, the anti-Covid-19 biological activity of some constituents of Buriti oil was investigated using in silico methods of Molecular Docking and Molecular Dynamics Simulations. The main results of Molecular Docking revealed favorable interaction energies in the formation of the 2GTB peptidase complex (main peptidase of SARS-CoV) with the 13-cis-ß-carotene ligands (ΔGbind = -10.23Kcal mol-1), 9-cis -ß-carotene (ΔGbind = -9.82Kcal mol-1), and α-carotene (ΔGbind = -8.34Kcal mol-1). Molecular Dynamics simulations demonstrated considerable interaction for these ligands with emphasis on α-carotene. Such theoretical results encourage and enable a direction for experimental studies in vitro and in vivo, essential in the development of new drugs with enzymatic inhibitory action for Covid-19.Communicated by Ramaswamy H. Sarma.

Evaluation of Nanostructured Lipid Carriers Produced with Interesterified Buriti Oil.

RESEARCH BACKGROUND: Extracted from the pulp of an Amazonian fruit, buriti oil is rich in micronutrients with antioxidant properties and high biological value. The few studies available indicate that this oil could be used in a wide range of applications; however, there are no studies that work on the improvement in the characteristics of this oil for commercial application. The enzymatic interesterification is one of the tools available to improve the properties of oils and fats and our recent studies have demonstrated that the lipase could specifically act on buriti oil to produce structured lipids rich in oleic acid, while preserving most of the minor compounds present in this oil. Still looking for ways to expand the applicability of this raw oil, in this work, we are interested in studying the behaviour of this structured oil in nanostructured lipid carriers (NLCs). EXPERIMENTAL APPROACH: The NLCs were produced with interesterified buriti oil and the stability, droplet size, electrical charge, microstructure, polymorphism and antioxidant activity of the samples were evaluated by ORAC and FRAP methods. RESULTS AND CONCLUSIONS: The results showed that the interesterification formed more unsaturated triacylglycerols (TAGs), and NLCs prepared with interesterified buriti oil had smaller droplets than NLCs with crude buriti oil. Particles remained stable throughout the storage period and NLCs exhibited complex polymorphism with the presence of three crystalline forms. The oxygen radical absorbance capacity (ORAC) value was approx. 23% higher in nanolipid carries with structured lipids than in the nanolipid carriers with crude buriti oil, and the ferric reducing antioxidant power (FRAP) value 16% higher, demonstrating the influence of interesterification on the antioxidant activity of nanocarriers. Thus, NLCs prepared with interesterified buriti oil had small droplets, high stability and antioxidant capacity, and have a potential for nutritional and biological applications. NOVELTY AND SCIENTIFIC CONTRIBUTION: This research showed that interesterification positively influenced the physicochemical properties of NLCs, producing the oil rich in oleic acid, high stability and antioxidant capacity. Therefore, it may be interesting to use these nanocarriers to obtain efficient carrier systems for future applications.

Buriti Oil Emulsions as Affected by Soy Protein Isolate/High-Methoxyl Pectin Ratio, Oil Content and Homogenization Pressure.

RESEARCH BACKGROUND: Emulsion technology is a suitable way of encapsulating, protecting and releasing hydrophobic bioactive compounds for application in food industries, but they are thermodynamically unstable systems. Good results have been achieved for emulsions stabilized by protein-polysaccharide complexes subjected to high-pressure homogenization. Improved stabilization of oil-in-water emulsions results from electrostatic complexes formed between proteins and polysaccharides at pH lower than the protein isoelectric point, which adsorb at the oil-water interface. In addition, polysaccharides contribute to emulsion stability by increasing viscosity of the continuous phase. The aim of this work is to investigate the production of carotenoid-rich buriti oil emulsions using soy protein isolate and high-methoxyl pectin as stabilizers. EXPERIMENTAL APPROACH: Using a rotatable central composite experimental design, we assessed the effects of oil content, soy protein isolate/high-methoxyl pectin ratio and homogenization pressure on the stability, droplet size, electrical conductivity, electrical charge, microstructure and rheological behaviour of the emulsions. RESULTS AND CONCLUSIONS: An optimized emulsion was produced with 28% buriti oil, 55% soy protein isolate, and homogenization pressure of 380·105 Pa. This emulsion was stable for at least seven days, presenting reduced average droplet size, low electrical conductivity and high modulus of negative charges. The mechanical spectra showed that the emulsion behaved as a viscoelastic gel under oscillatory, non-destructive shearing, whereas shear-thinning behaviour took place under steady shear conditions. NOVELTY AND SCIENTIFIC CONTRIBUTION: The optimized buriti oil emulsions stabilized by soy protein isolate and high-methoxyl pectin could be suitable for fat substitution, energy reduction and carotenoid enrichment in food products, such as dairy and bakery products, ice cream, salad sauces and vegetable-based cream.

Evaluation of cytotoxicity of nanolipid carriers with structured Buriti oil in the Caco-2 and HepG2 cell lines.

Buriti oil is rich in monounsaturated fatty acids, carotenoids and tocopherols and it is used for the treatment of various diseases. One strategy to restructure the triglycerides is enzymatic interesterification and nanocarriers have been employed to improve the solubility, bioavailability and stability of active compounds. This work aims to investigate the in vitro cytotoxicity of this structured oil in nanoemulsions and nanostructured lipid carriers to expand the applicability of the crude oil. None of the samples had a cytotoxic effect on Caco-2 and HepG2 cell lines at the concentrations tested. Structured lipids acted protecting against oxidative stress and lipid peroxidation. Additionally, no consumption of glutathione has been observed in both cells, and the compounds present in buriti oil are possibly acting as antioxidants. Thus, nanoparticles prepared with interesterified buriti oil had low cytotoxicity and high oxidative stability, with great potential for future applications.

Physicochemical characterization and antimicrobial activity in novel systems containing buriti oil and structured lipids nanoemulsions.

Buriti oil nanoemulsions were prepared using non-interesterified buriti oil or buriti oil interesterified for 6 or 24 h (NBO, NBO6h, and NBO24 h), respectively. The aim was to investigate the effects of interesterified oils on the physicochemical and biological properties of nanoemulsions. Samples were stored at 4 and 25 °C for 30 days, and their physicochemical properties and biological activities were evaluated. The mean droplet diameter of nanoemulsions ranged from 196 to 270 nm. NBO24 h had the smallest droplet size and was the most stable during the storage period. Furthermore, NBO24 h demonstrating the good oxidative stability, had a high antioxidant capacity, and was less susceptible to droplet aggregation. NBO and NBO24 h had similar biological activity against Gram-negative bacteria (Escherichia coli O157: H7); bacterial growth was inhibited by at least 60% at 3.12 mg mL-1. The nanoemulsions have interesting properties for the production of pharmaceutical, cosmetic, and food formulations with antimicrobial activity.

Antioxidant Potential and Modulatory Effects of Restructured Lipids from the Amazonian Palms on Liver Cells.

Enzymatic interesterification is used to manipulate oil and fat in order to obtain improved restructured lipids with desired technological properties. However, with raw materials containing significant amounts of bioactive compounds, the influence of this enzymatic process on the bioactivity of the final product is still not clear. Thus, the aim of this study is to evaluate the antioxidant potential and modulatory effects of two raw materials from the Amazonian area, buriti oil and murumuru fat, before and after lipase interesterification, on human hepatoma cells (HepG2). The results indicate that minor bioactive compounds naturally found in the raw materials and their antioxidant capacity are preserved after enzymatic interesterification, and that the restructured lipids modulate HepG2 endogenous antioxidant enzyme.

Application of lipases to regiospecific interesterification of exotic oils from an Amazonian area.

Enzymatic interesterification may favor the development of lipid fractions from Amazonian oils with greater application potential. In this study, the Amazonian buriti oil and murumuru fat were subjected to enzymatic interesterification using two lipases in three different enzyme systems: one with a commercial lipase from Thermomyces lanuginosa, a second with the lipase produced by Rhizopus sp., and a third with a mixture of both lipases. The three enzyme systems were able to catalyze the reaction, but the enzymes showed different specificities. The commercial lipase was specific for unsaturated fatty acids, whereas the Rhizopus sp. lipase was specific for both unsaturated fatty acids and the positions sn -1 and sn -3 of the fatty acid on the triacylglycerol. The mixture of both lipases showed no synergistic effect: the results were intermediate between the two enzymes applied alone. Interesterification reduced the levels of trisaturated and triunsaturated triacylglycerols and increased the levels of diunsaturated-monosaturated and monounsaturated-disaturated triacylglycerols. The thermal melting behavior indicated the formation of a single endothermic region with more homogeneous triacylglycerols. The content of the bioactive ß-carotene was preserved after the interesterification reaction with all three-enzyme systems. The interesterified lipids obtained, because of the characteristics of the oils, may be applied to the formulation of cosmetics and pharmaceuticals.

Atividade antibacteriana e cicatrizante do óleo de buriti Mauritia flexuosa L. / Antibacterial and healing activities of buriti oil Mauritia flexuosa L.

O objetivo deste estudo foi avaliar a atividade antibacteriana in vitro e cicatrizante do óleo de buriti (M. flexuosa) em feridas realizadas em ratos (Rattus norvegicus albinus). Para a avaliação antibacteriana in vitro, foram utilizados cinco patógenos bacterianos incluindo espécies gram-positivas e espécies gram-negativas mediante o uso do método de difusão em ágar. Para a avaliação da atividade cicatrizante, foram utilizados 40 ratos da linhagem Wistar, divididos em dois grupos: o grupo I, composto por 20 ratos com feridas cutâneas, tratados com aplicação tópica do creme base com 10 por cento de óleo de buriti, e o grupo II, controle, com o mesmo número de animais que receberam a aplicação tópica do creme base. A aplicação do produto foi realizada em feridas padronizadas, circulares de 1cm de diâmetro na região dorsolombar. As avaliações clínica, morfométrica e histopatológica das feridas foram realizadas no 3°, 7°, 14° e 21° dias. Em relação à avaliação da atividade antibacteriana, os resultados mostraram que houve inibição do crescimento bacteriano em quatro dos cinco patógenos testados. Em relação à área da ferida, foi observada redução significativa da área no 14o dia e maior percentual de contração das feridas do grupo tratado em relação ao controle. No décimo quarto dia, as feridas tratadas com o óleo do buriti apresentavam aumento significativo na contagem de fibroblastos e fibras colágenas, além de completo processo de reepitelização, enquanto o grupo controle necessitava de mais tempo para resolução do processo cicatricial.

The aim of this study was to evaluate the in vitro antimicrobial activity and wound healing effect of buriti oil (M. flexuosa) in rats. To evaluate the in vitro antimicrobial activity, five species of bacteria, including both gram-negative and gram-positive, were tested by the agar diffusion method. To assess the wound healing effect, 40 rats of Wistar lineage were clustered into two groups: G1, composed by 20 rats with cutaneous wounds and treated using topic administration of basic cream containing 10 percent of buriti oil; and G2 or control group, composed by 20 rats with cutaneous wounds and treated using topic administration of basic cream without any buriti oil. The cream administration was performed on circular wounds of 1 cm area in the lumbodorsal region. Clinical, histopathologic and morphometric evaluations of the wounds were done in 3rd, 7th, 14th and 21th days. Four from five bacteria species tested had growing inhibition, which demonstrates the antimicrobial potential of buriti oil. A significant reduction on the wound area with contraction of the edges was found for G1 in the 14th day. On this same day, the wounds treated using buriti oil showed an increase in the fibroblasts and collagen fibers countings and complete reephitelialization, characteristics not demonstrated by G2.