Development, Physicochemical Characterization and In Vitro Anti-Inflammatory Activity of Solid Dispersions of α,β Amyrin Isolated from Protium Oilresin

Review: The Chemistry, Toxicity and Antibacterial Activity of Curcumin and Its Analogues

Antimicrobial resistance is a global challenge that is already exacting a heavy price both in terms of human health and financial cost. Novel ways of approaching this crisis include the investigation of natural products. Curcumin is the major constituent in turmeric, and it is commonly used in the preparation of Asian cuisine. In addition, it possesses a wide range of pharmacological properties. This review provides a detailed account of curcumin and its analogues' antibacterial activity against both gram-positive and gram-negative isolates, including its potential mechanism(s) of action and the safety and toxicity in human and animal models. We also highlight the key challenges in terms of solubility/bioavailability associated with the use of curcumin and include research on how these challenges have been overcome.

Current Trends on Solid Dispersions: Past, Present, and Future

Solid dispersions have achieved significant interest as an effective means of enhancing the dissolution rate and thus the bioavailability of a range of weakly water-soluble drugs. Solid dispersions of weakly water-soluble drugs with water-soluble carriers have lowered the frequency of these problems and improved dissolution. Solid dispersion is a solubilization technology emphasizing mainly on, drug-polymer two-component systems in which drug dispersion and its stabilization is the key to formulation development. Therefore, this technology is recognized as an exceptionally useful means of improving the dissolution properties of poorly water-soluble drugs and in the latest years, a big deal of understanding has been accumulated about solid dispersion, however, their commercial application is limited. In this review article, emphasis is placed on solubility, BCS classification, and carriers. Moreover, this article presents the diverse preparation techniques for solid dispersion and gathers some of the recent technological transfers. The different types of solid dispersions based on the carrier used and molecular arrangement were underlined. Additionally, it summarizes the mechanisms, the methods of preparing solid dispersions, and the marketed drugs that are available using solid dispersion approaches.

α-Amyrin induces GLUT4 translocation mediated by AMPK and PPARδ/γ in C2C12 myoblasts

α-Amyrin, a natural pentacyclic triterpene, has an antihyperglycemic effect in mice and dual PPARδ/γ action in 3T3-L1 adipocytes, and potential in the control of type 2 diabetes (T2D). About 80% of glucose uptake occurs in skeletal muscle cells, playing a significant role in insulin resistance (IR) and T2D. Peroxisome-proliferator activated receptors (PPARs), in particular PPARδ and PPARγ, are involved in the regulation of lipids and carbohydrates and, along with adenosine-monophosphate (AMP) - activated protein kinase (AMPK) and protein kinase B (Akt), are implicated in translocation of glucose transporter 4 (GLUT4); however, it is still unknown whether α-amyrin can affect these pathways in skeletal muscle cells. Our objective was to determine the action of α-amyrin in PPARδ, PPARγ, AMPK, and Akt in C2C12 myoblasts. The expression of PPARδ, PPARγ, fatty acid transporter protein (FATP), and GLUT4 was quantified using reverse transcription quantitative PCR and Western blot. α-Amyrin increased these markers along with phospho-AMPK (p-AMPK) but not p-Akt. Molecular docking showed that α-amyrin acts as an AMPK-allosteric activator, and may be related to GLUT4 translocation, as evidenced by confocal microscopy. These data support that α-amyrin could have an insulin-mimetic action in C2C12 myoblasts and should be considered as a bioactive molecule for new multitarget drugs with utility in T2D and other metabolic diseases.

Novel Solid Dispersions of Naphthoquinone Using Different Polymers for Improvement of Antichagasic Activity

IVS320 (3a,10b-dihydro-1H-cyclopenta[b]naphtho[2,3-d]furan-5,10-dione) is a naphthoquinone that has low solubility in aqueous medium, a physical behavior that limits its biological activities, considering that compounds from this class have several activities. In this work, solid dispersions (SDs) prepared between IVS320 and polymers hydroxypropyl methylcellulose (HPMC), polyethylene glycol (PEG), and polyvinylpyrrolidone (PVP) were developed using physical mixture (PM), kneading (KN), and rotary evaporation (RE) methods. Dispersions were investigated using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetry (TG), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). In addition, in vitro antiparasitic activity in Trypanosoma cruzi Y strains was evaluated. Physical-chemical characterization demonstrated the formation of SDs through the interaction of IVS320 with polymeric matrices. SDs of IVS320-polymer presented a significant potentiation of antichagasic activity, with inhibitory growth around 62% (IVS320-HPMC/RE), 55% (IVS320-PEG/RE), and 85% (IVS320-PVP/RE), while pure IVS320 showed a value of 48% for the highest concentrations evaluated (50 µg/mL).

Therapeutic Applications of Solid Dispersions for Drugs and New Molecules: In Vitro and In Vivo Activities

This review aims to provide an overview of studies that address the use, in therapeutic applications, of solid dispersions (SDs) with biological activities in vitro and/or in vivo mainly made up of polymeric matrices, as well as to evaluate the bioactive activity of their constituents. This bibliographic survey shows that the development of solid dispersions provides benefits in the physicochemical properties of bioactive compounds, which lead to an increase in their biological potential. However, despite the reports found on solid dispersions, there is still a need for biological assay-based studies, mainly in vivo, to assist in the investigation and to devise new applications. Therefore, studies based on such an approach are of great importance to enhance and extend the use of solid dispersions in the most diverse therapeutic applications.

Leishmanicidal, Trypanocidal and Antioxidant Activity of Amyrin-Rich Extracts from Eugenia pyriformis Cambess

AIMS

This study aimed to characterize and evaluate leishmanicidal and trypanocidal action as well as cytotoxicity on macrophages and antioxidant ability of extracts, obtained by supercritical CO₂ and ultrasound-assisted extractions of Uvaia (Eugenia pyriformis) leaves.

METHODS

Leaves from E. pyriformis were submitted to supercritical CO₂ (E1) and ultrasound-assisted (E2) extractions. The characterization of extracts was done using GC-MS and HPLC. L. amazonensis (promastigotes) and T. cruzi (epimastigotes and trypomastigotes) were treated with crescent concentrations of E1 and E2. After this, parasites were counted and the percentage of inhibition and IC₅₀/LC₅₀ was calculated. Murine macrophages were treated with both extracts for 48 h and after that, the cellular viability was determined and CC₅₀ was calculated. DPPH method was used to determine the antioxidant capacity of both extracts.

RESULTS

The results of identification showed a great amount of α and β-amyrin in E1 and E2. Both extracts showed growth inhibition of L. amazonensis with an IC₅₀ of 5.98 and 9.38 μg/mL to E1 and E2, showing a selectivity index > 30. In trypanocidal tests, an LC₅₀ of 16.69 and 7.80 μg/mL (trypomastigotes) and IC₅₀ of 5.56 and 34.34 μg/mL (epimastigotes) was reached by E1 and E2. Both extracts showed no toxicity to macrophages and an antioxidant capacity similar to the positive control (tocopherol).

CONCLUSIONS

This is the first study demonstrating the activity of an amyrin rich-extract against microorganisms that cause Chagas disease and leishmaniasis, as well as its antioxidant capacity, justifying further studies for future in - vivo tests.