Optimization of extraction method and evaluation of antileishmanial activity of oil and nanoemulsions of Pterodon pubescens benth. fruit extracts.

Currently, leishmaniasis is difficult to manage owing to the limited choice and high toxicity of available drugs, and emergence of drug-resistant protozoa. Medicinal plants, which produce various bioactive molecules, can help counter this global shortage. In this study, we prepared Pterodon pubescens fruit extracts, which show antileishmanial activity, and developed a nanoemulsion of the optimized extract to improve its performance. The extracts were prepared using conventional methods and a supercritical fluid method and were tested for activity against Leishmania amazonensis promastigotes and amastigotes. The two most effective extracts were formulated as nanoemulsions. Although both extracts showed cytotoxicity, the supercritical extracts were more effective against L. amazonensis promastigotes and amastigotes than conventional extracts were. This was attributed to the high content of the geranylgeraniol derivative in the supercritical extracts. The nanoemulsions showed a better selectivity index and significantly improved activity against parasites (IC50: 2.7 µg/mL for nanoemulsion of hexane extract; IC50: 1.9 µg/mL for nanoemulsion of supercritical extract) compared to the Miltefosine standard (0.7 µg/mL). This could be due to the smaller droplets of the supercritical extracts, allowing better penetration. In conclusion, the extracts showed promise in in vitro tests, and could be used as a leishmaniasis treatment.

Nanoparticles of Waste Material of Propolis and Gelatin as a Novel System for Delivery of L-Ascorbic Acid.

BACKGROUND: The waste material from the preparation of propolis extracts is a potential natural compound for application in pharmaceutical and medicine nanostructured products. Ascorbic acid is an excellent antioxidant and an important cofactor of several physiological and biochemical processes. OBJECTIVE: The aim of this study was to develop and characterize nanoparticles containing L-ascorbic acid prepared with propolis byproduct. METHOD: Nanoparticle's physicochemical characteristics (surface morphology, particle size, zeta potential, and entrapment efficiency), antioxidant activity, in vitro release profile, and in vitro cytotoxicity were evaluated. RESULTS: Nanoparticles showed to be spherical, with agglomeration, mean diameter between 110.93 and 480.59 nm, zeta potential near zero and good entrapment efficiency. Antioxidant activity of L-ascorbic acid increased when nanoencapsulated and the drug release was prolonged, controlled mainly by the phenomenon of relaxation of polymer chains and dependent of propolis residue concentration. The application of technology provided a reduction in the level of cytotoxicity of L-ascorbic acid, and the nanoparticles showed a protective effect on macrophages.

Inhibitory Effect of the Hexane Fraction of the Ethanolic Extract of the Fruits of Pterodon pubescens Benth in Acute and Chronic Inflammation.

Fruits of Pterodon pubescens Benth have been used traditionally for the treatment of rheumatism, sore throat, and respiratory disorders, and also as anti-inflammatory, analgesic, depurative, tonic, and hypoglycemic agent. The study was aimed at evaluating the anti-inflammatory activity of the hexane fraction of an ethanolic extract of P. pubescens fruits. The oil from P. pubescens fruits was extracted with ethanol and partitioned with hexane. The anti-inflammatory activity was measured with increasing doses of the hexane fraction (FHPp) by using a carrageenan-induced rat model of pleurisy and a rat model of complete Freund's adjuvant-induced arthritis by using an FHPp dose of 250 mg/kg for 21 days. Treatment with an FHPp resulted in anti-inflammatory activity in both models. The results of biochemical, hematological, and histological analyses indicated a significant decrease in glucose, cholesterol, and triglycerides levels (18.32%, 34.20%, and 41.70%, resp.) and reduction in the numbers of total leukocytes and mononuclear cells. The FHPp dose of 1000 mg/kg induced no changes in behavioral parameters, and no animal died. The results of this study extend the findings of previous reports that have shown that administration of extracts and fractions obtained from species of the genus Pterodon exhibits anti-inflammatory activity and lacks toxicity.

Preparation and characterization of microcapsules of Pterodon pubescens Benth. by using natural polymers

An oleaginous fraction obtained from an alcohol extract of the fruit of Pterodon pubescens Benth. (FHPp) was microencapsulated in polymeric systems. These systems were developed using a complex coacervation method and consisted of alginate/medium-molecular-weight chitosan (F1-MC), alginate/chitosan with greater than 75% deacetylation (F2-MC), and alginate/low-molecular-weight chitosan (F3-MC). These developed systems have the potential to both mask the taste of the extract, and to protect its constituents against possible chemical degradation. The influence of the formulation parameters and process were determined by chemical profiling and measurement of the microencapsulation efficiency of the oleaginous fraction, and by assessment of microcapsule morphology. The obtained formulations were slightly yellow, odorless, and had a pleasant taste. The average diameters of the microcapsules were 0.4679 µm (F2-MC), 0.5885 µm (F3-MC), and 0.9033 µm (F1-MC). The best formulation was F3-MC, with FHPp microencapsulation efficiency of 61.01 ± 2.00% and an in vitro release profile of 75.88 ± 0.45%; the content of vouacapans 3-4 was 99.49 ± 2.80%. The best model to describe the release kinetics for F1-MC and F3-MC was that proposed by Higuchi; however, F2-MC release displayed first-order kinetics; the release mechanism was of the supercase II type for all formulations.

Uma fração oleaginosa obtida do extrato etanólico de frutos de Pterodon pubescens Benth (FHPp) foi microencapsulada em um sistema polimérico. Estes sistemas foram desenvolvidos utilizando o método de coacervação complexa, constituído de alginato/quitosana massa molecular média (F1-MC), alginato/quitosana com desacetilação superior a 75% (F2-MC) e alginato/quitosana de massa molecular baixa (F3-MC). Estes sistemas desenvolvidos têm o potencial tanto de mascarar o sabor do extrato, quanto de protegê-lo de possível degradação química. A influência dos parâmetros de formulação e processo foram determinadas por caracterização química, determinação da eficiência de microencapsulação da fração oleaginosa e por avaliação morfológica da microcápsula. As formulações mostraram-se ligeiramente amareladas, inodoras e com sabor agradável. Os diâmetros médios das microcápsulas foram de 0,4679 µm (F2-MC), 0,5885 µm (F3-MC) e 0,9033 µm (F1-MC). A melhor formulação foi F3-MC, considerando-se que apresentou eficiência de encapsulação de 61,01 ± 2,00%, e perfil de liberação in vitro de 75,88 ± 0,45%; o conteúdo dos vouacapanos 3-4 foi 99,49 ± 2,80%. O melhor modelo para descrever a cinética de liberação foi o modelo proposto por Higuchi para F1-MC e F3-MC, entretanto, para F2-MC foi o modelo de primeira ordem, e o mecanismo de liberação foi do tipo super caso II para todas as formulações.