Emulgel based on amphotericin B and bacuri butter (Platonia insignis Mart.) for the treatment of cutaneous leishmaniasis: characterization and in vitro assays

Advanced amphotericin-B gel formulation: An efficient approach to combat cutaneous leishmaniasis

Several drug release studies are continuously carried out to minimize pharmacological limitations, such as insolubility in water and gastrointestinal irritability. This study focused on the development of gels for the administration of amphotericin-B (AmB) for the treatment of cutaneous leishmaniasis. Two gels were prepared from copolymers (polyglycerol and ε-caprolactone) incorporated with AmB. The gels were characterized by FTIR, NMR, TG, and DSC techniques. The incorporation of AmB into the copolymers showed that the medicine remained in the monomeric form, which is the least toxic. The AmB loading presented values of about 31 % (w:w) for TMP-HPG-PCL and for GLY-HPG-PCL, while the encapsulation efficiency was 93 % for both copolymers. According to the release profile, it is observed that, after 48 h, the percentage of AmB released for pure amphotericin, TMP-HPG-PCL-AmB, and GLY-HPG-PCL-AmB were 100 % ± 6 %, 100 % ± 1.5 %, and 47 % ± 13, respectively. Hemolytic study, Cytotoxic Evaluation showed that TMP-HPG-PCL and GLY-HPG-PCL were not toxic to both cell lines (HaCat and MCF-7). These results suggest that the copolymers are safe for in vivo applications being able to act as a drug carrier that have low water solubility corroborating their purpose of polymeric support in the transport of drugs. TMP-HPG-PCL-POL-AmB and for GLY-HPG-PCL-HPG-POL-AmB were used in female mice (BALB/c) infected with Leishmania major foremost for 40 days, and it was found that in animals treated with the gel/copolymer/AmB, there was a reduction in the number of parasites of around 70 %. Histopathological studies showed the presence of small intralobular granulomas and moderate Kupffer cell hypertrophy/hyperplasia. The results show that the TMP-HPG-PCL-POL-AmB and for GLY-HPG-PCL-HPG-POL-AmB efficiently combats cutaneous leishmaniasis.

Platonia insignis: A Systematic Synthesis of Scientific Studies on Its Biology, Ecology, and Potential Applications

Platonia insignis, a native tree from the Amazon, has a high market demand due to its various uses, such as producing pulps and ice creams from its fruit and furniture from its wood. This review aims to systematize the scientific knowledge about the species and explore the potential of biotechnology to elucidate its growth, development, and fruiting mechanisms. Databases such as the Web of Science, Scopus, the Brazilian Agricultural Research Database, and PubMed were consulted using keywords like "P. insignis", "bacuri", and "bacurizeiro". Of the 67 selected articles, it was observed that rigorous research on P. insignis is limited. Current management is based on empirical observations, but biotechnology could expedite the domestication process. Additionally, studying medicinal compounds from P. insignis could open new economic opportunities, encourage germplasm conservation, and drive genetic breeding.

Amazonian Fruits for Treatment of Non-Communicable Diseases

PURPOSE OF REVIEW

The Amazon region has a high biodiversity of flora, with an elevated variety of fruits, such as Camu-Camu (Myrciaria dúbia), Açaí (Euterpe oleracea Mart.), Tucumã (Astrocaryum aculeatum and Astrocaryum vulgare), Fruta-do-conde (Annona squamosa L.), Cupuaçu (Theobroma grandiflorum), Graviola (Annona muricata L.), Guarana (Paullinia cupana Kunth var. sorbilis), and Pitanga (Eugenia uniflora), among many others, that are rich in phytochemicals, minerals and vitamins with prominent antioxidant and anti-inflammatory potential.

RECENT FINDINGS

Studies evaluating the chemical composition of these fruits have observed a high content of nutrients and bioactive compounds. Such components are associated with significant biological effects in treating various non-communicable diseases (NCDs) and related complications. Regular intake of these fruits from Amazonas emerges as a potential therapeutic approach to preventing and treating NCDs as a nutritional strategy to reduce the incidence or mitigate common complications in these patients, which are the leading global causes of death. As studies remain largely unexplored, this narrative review discusses the possible health-beneficial effects for patients with NCDs.

Evaluation of the acute toxicity of ellagic acid and gallic acid incorporated in Poloxamer407® gel, in Zophobas morio larvae

Gallic acid (GA) has antioxidant, anti-inflammatory and antimicrobial properties, while ellagic acid (EA) demonstrates anticancer, antiviral and photoprotective activity. In this study, the combination of these substances incorporated into a poloxamer gel was tested to verify the individual effect of the substances, in addition to taking advantage of a probable complementary effect, aiming to provide additional therapeutic benefits. As a result of the incorporation, formulations containing GA, EA and GA + EA were obtained, which were evaluated for the effects of the Freeze-thaw cycle on pH, which revealed a significant decrease (p < 0.05) in most samples, including the vehicle (without drug) and the gel containing both drugs. No sample showed variation outside the normal pH range for the skin, with values ranging from 4.8 to 6.0. Regarding conductivity, the GA, EA and GA + EA formulations showed a reduction (p < 0.05) after the freeze-thaw cycle. The drug content in the formulations ranged from 95.86% to 101.35% initially to 91.30% to 101.51% after the freeze-thaw cycle. Regarding the drug release, the results revealed the following cumulative percentages: GA-3% - 92.58% after 1.5 h; AE-3% - 51.60% after 6 h; GA + EA (1.5% = 1.5%) - 99.91% after 2 h; GA + EA- (1.5% = 1.5%) released 57.06%, after 6 h. Regarding toxicity, it was observed that the group treated with GA showed a lower survival rate of the larvae (40%) at the dose 3000 mg/Kg in the formulation. Following the same trend, in the acute lethal concentration (ALC50) test performed using Zophobas morio larvae, an ALC50 of 2191.51 mg/Kg was observed for GA at 48 h. Melanin analysis showed a decrease in concentrations of 30 mg/Kg in the GA group, 3 mg/Kg of EA and 3, 300, 3000 mg/Kg of GA + EA, of the pure drugs. In the groups with the drugs incorporated into the gel, there was a significant decrease (P < 0.05) in melanin in the vehicle (gel), at concentrations of 300 and 3000 mg/Kg of GA and EA. On the other hand, in the combination of GA + EA, a reduction was observed at concentrations of 3 and 30 mg/Kg when compared to the control group. Thus, the gel showed good quality as a pharmaceutical formulation for topical use and low toxicity, making it promising for use in skin therapies.

Emulgel-loaded mannosylated thiolated chitosan-coated silver nanoparticles for the treatment of cutaneous leishmaniasis

Topical treatment of cutaneous leishmaniasis holds great promise for decreasing drug associated side effects and improving efficacy. This study was aimed to develop mannosylated thiolated chitosan-coated silver nanoparticles (MTCAg) loaded emulgel for the treatment of cutaneous leishmaniasis. MTC-Ag were synthesized via a chemical reduction method and were loaded into the emulgel. The nanoparticles had a zeta potential of +19.8 mV, an average particle size of 115 nm and a narrow polydispersity index of 0.26. In-vitro release profiles showed controlled release of silver ions from both the MTC-Ag and the emulgel-loaded MTC-Ag nanoparticles after 24 h. An ex-vivo retention study indicated 5 times higher retention of silver by the emulgel-loaded MTC-Ag than by the MTC-Ag nanoparticles. The in-vitro anti-leishmanial assay revealed that MTC-Ag had an excellent inhibitory effect on intracellular amastigotes, leading to ~90 % inhibition at the highest concentration tested. A 4-fold reduction in the IC₅₀ value was found for MTC-Ag compared to blank Ag nanoparticles. Cytotoxicity assay showed 83 % viability of macrophages for MTC-Ag and 30 % for Ag nanoparticles at a concentration of 80 μg/mL, demonstrating the improved biocompatibility of the polymeric nanoparticles. Drug release and retention studies corroborate the great potential of MTC-Ag-loaded emulgel for the treatment of cutaneous leishmaniasis.

The ethnobotanical relevance of the tribe Symphonieae (Clusiaceae) around the world

ETHNOPHARMACOLOGICAL RELEVANCE

The tribe Symphonieae (Clusiaceae) encompasses 48 species accommodated in seven genera (Lorostemon, Montrouziera, Moronobea, Pentadesma, Platonia, Symphonia and Thysanostemon). Parts of these plants, mainly the exudates and the seeds oil are useful for different purposes, especially for treating dermatological conditions. In addition to the role in the folk medicine, some species are of great economic and cultural importance for native people from different continents.

AIM OF THE REVIEW

The goal of this review is to critically summarize the current knowledge on systematics, ethnobotanical, chemical and pharmacological aspects of species from the tribe Symphonieae, as well as to provide support for future taxonomic and phylogenetic studies on the Clusiaceae family.

MATERIALS AND METHODS

The available information was gathered from many different databases (Web of Science, ScienceDirect, Scopus, Pubmed, ChemSpider, SciFinder, ACS Publications, Wiley Online Library, Useful Tropical Plants Database, Google Scholar). Additional data from books, theses and dissertations were also included in this review.

RESULTS

Chemical studies of Symphonieae have demonstrated that the genera are a source of benzophenones, xanthones and biflavonoids. Components as sesquiterpenoids, triterpenoids, flavonoids, free fatty acids, among others, have also been reported. Extracts and compounds isolated from a variety of species have been exhibiting antimicrobial, cytotoxic and antiprotozoal activities, corroborating part of their medicinal uses. In addition, certain species produce edible fruits and a kind of "butter" with economic importance. All species produce exudate, which often has great relevance in the daily lives of local people.

CONCLUSION

Several species of Symphonieae have potential therapeutic applications and some of them have been investigated to scientifically validate their popular uses. In addition, a number of species have proved to be a rich source of promising pharmacologically active compounds. Finally, the value of fruits, exudate and butter, for instance, should serve as a stimulus for the sustainable development of products that aim to take advantage of these natural resources.

An appraisal of the scientific current situation and new perspectives in the treatment of cutaneous leishmaniasis

Leishmaniasis is a Neglected Tropical Diseases caused by protozoan parasites of the genus Leishmania. It is a major health problem in many tropical and subtropical regions of the world and can produce three different clinical manifestations, among which cutaneous leishmaniasis has a higher incidence in the world than the other clinical forms. There are no recognized and reliable means of chemoprophylaxis or vaccination against infections with different forms of leishmaniasis. In addition, chemotherapy, unfortunately, remains, in many respects, unsatisfactory. Therefore, there is a continuing and urgent need for new therapies against leishmaniasis that are safe and effective in inducing a long-term cure. This review summarizes the latest advances in currently available treatments and improvements in the development of drug administration. In addition, an analysis of the in vivo assays was performed and the challenges facing promising strategies to treat CL are discussed. The treatment of leishmaniasis will most likely evolve into an approach that uses multiple therapies simultaneously to reduce the possibility of developing drug resistance. There is a continuous effort to discover new drugs to improve the treatment of leishmaniasis, but this is mainly at the level of individual researchers. Undoubtedly, more funding is needed in this area, as well as greater participation of the pharmaceutical industry to focus efforts on the development of chemotherapeutic agents and vaccines for this and other neglected tropical diseases.

Amphotericin B-Loaded Emulgel: Effect of Chemical Enhancers on the Release Profile and Antileishmanial Activity In Vitro

Cutaneous leishmaniasis is a neglected parasitic disease. Treatment is preferably performed with pentavalent antimony associated or not with amphotericin B (AmB). This study aimed to develop an emulgel with different chemical enhancers of cutaneous release. Initially, AmB emulsions were obtained with the chemical promoters, oleic acid and geraniol and without promoter, then for the evaluation of the formulations, a preliminary stability study was carried out where the formulations were submitted to centrifugation, before and after the freeze-thaw cycle and analyzed appearance, color, pH, spreadability, viscosity, conductivity, droplet size, assay, in vitro release study, in vitro antileishmania activity in Leishmania major promastigotes, and macrophage toxicity in the MTT test. The emulsions were yellowish, with no signs of instability after the centrifugation test. The pH range corresponded to that of the skin, which is 4.6 to 5.8, before and after the freeze-thaw cycle, the formulations had good spreadability and did not present significant viscosity differences before and after the freeze-thaw cycle, presenting a non-Newtonian characteristic. AmB content was within the kinetic model of zero order release, the formulation of 3% AmB and 5% oleic acid (formulation 1) was chosen to proceed with the antileishmania activity test and showed potential activity against the in vitro parasite with significant reduction of cytotoxicity on murine macrophages, indicating that the formulation is promising for the treatment of cutaneous leishmaniasis.