Annatto Oil Loaded Nanostructured Lipid Carriers: A Potential New Treatment for Cutaneous Leishmaniasis

Parabens alter the surface characteristics and antibiotic susceptibility of drinking water bacteria

Parabens are markedly present in products of daily use, considered emerging environmental contaminants that can harm human health and aquatic life, due to their release into aquatic sources. The impact of the exposure of microbial communities to parabens remains unclear. This study investigates aspects of the mode of action of methylparaben (MP), propylparaben (PP), butylparaben (BP), and MIX at environmental (15 μg/L) and in-use (15000 μg/L) concentrations, against two bacterial strains of Acinetobacter calcoaceticus and Stenotrophomonas maltophilia previously isolated from drinking water (DW). BP showed the strongest antimicrobial activity, while MP exhibited the weakest. The mechanism of action of parabens at the selected concentrations was found to be related to perturbations on physicochemical bacterial cell surface properties and charge, by causing an increase of bacterial cell envelope hydrophilicity and zeta potential values. In addition, parabens may activate osmotic regulation mechanisms as observed by the increase in vacuole area for MP-exposed A. calcoaceticus. The bacterial metabolic activity as well as bacterial size was also affected by parabens exposure. MP exposure further enhanced the biofilm formation ability and increased bacterial tolerance to antibiotics. The results raise environmental implications, particularly concerning water quality and public health, as parabens exposure can potentiate the virulence of DW bacteria, increasing the risk of human exposure to harmful microorganisms.

Annatto (Bixa orellana)-Based Nanostructures for Biomedical Applications-A Systematic Review

Plants are a source of valuable organic chemical compounds with complex structures rich in therapeutic activities. The encapsulation of compounds in nanostructured systems is an alternative to avoid limitations, such as instability and low solubility, and to promote therapeutic use. The objective of the present review was to summarize the data in the literature on the physicochemical characteristics, biomedical efficacy, and toxicity of nanostructures containing extracts and oils obtained from annatto (Bixa orellana). For this, searches were conducted in the CINAHL, LILACS, Embase, FSTA, MEDLINE, ProQuest, PubMed, ScienceDirect, Scopus, and Web of Science databases. Studies that carried out the development, physical-chemical characterization, and evaluation of therapeutic efficacy and/or in vitro, in vivo, or clinical toxicity of nanostructures containing extracts and oils derived from annatto were included in the review. Of the 708 articles found, nine met the inclusion criteria. The included studies developed different nanostructures (nanofibers, nanocochleates, chitosan, lipid, polymeric, and metallic nanoparticles). These nanostructures showed leishmanicidal, photoprotective, antioxidant, antimicrobial, and immunomodulatory efficacy, and tissue regeneration potential with no or low toxic effects in the tested models. Thus, the present work supports the nanostructuring of annatto extracts and oils as a relevant approach to the development of new technologies for biomedical applications.

From Extraction to Stabilization: Employing a 22 Experimental Design in Developing Nutraceutical-Grade Bixin from Bixa orellana L

Bixin is the main carotenoid found in the outer portion of the seeds of Bixa orellana L., commercially known as annatto. This compound is industrially employed in pharmaceutical, cosmetic, and food formulations as a natural dye to replace chemical additives. This study aimed to extract bixin from annatto seeds and obtain encapsulated bixin in a powder form, using freeze-drying encapsulation and maltodextrin as encapsulating agent. Bixin was extracted from annatto seeds employing successive washing with organic solvents, specifically hexane and methanol (1:1 v/v), followed by ethyl acetate and dichloromethane for subsequent washes, to effectively remove impurities and enhance bixin purity, and subsequent purification by crystallization, reaching 1.5 ± 0.2% yield (or approximately 15 mg of bixin per gram of seeds). Bixin was analyzed spectrophotometrically in different organic solvents (ethanol, isopropyl alcohol, dimethylsulfoxide, chloroform, hexane), and the solvents chosen were chloroform (used to solubilize bixin during microencapsulation) and hexane (used for spectrophotometric determination of bixin). Bixin was encapsulated according to a 22 experimental design to investigate the influence of the concentration of maltodextrin (20 to 40%) and bixin-to-matrix ratio (1:20 to 1:40) on the encapsulation efficiency (EE%) and solubility of the encapsulated powder. Higher encapsulation efficiency was obtained at a maltodextrin concentration of 40% w/v and a bixin/maltodextrin ratio of 1:20, while higher solubility was observed at a maltodextrin concentration of 20% w/v for the same bixin/maltodextrin ratio. The encapsulation of this carotenoid by means of freeze-drying is thus recognized as an innovative and promising approach to improve its stability for further processing in pharmaceutical and food applications.

Curcumin-loaded nanostructured systems for treatment of leishmaniasis: a review

Leishmaniasis is a neglected tropical disease that has affected more than 350 million people worldwide and can manifest itself in three different forms: cutaneous, mucocutaneous, or visceral. Furthermore, the current treatment options have drawbacks which compromise efficacy and patient compliance. To face this global health concern, new alternatives for the treatment of leishmaniasis have been explored. Curcumin, a polyphenol obtained from the rhizome of turmeric, exhibits leishmanicidal activity against different species of Leishmania spp. Although its mechanism of action has not yet been fully elucidated, its leishmanicidal potential may be associated with its antioxidant and anti-inflammatory properties. However, it has limitations that compromise its clinical use. Conversely, nanotechnology has been used as a tool for solving biopharmaceutical challenges associated with drugs, such as curcumin. From a drug delivery standpoint, nanocarriers (1-1000 nm) can improve stability, increase solubility, promote intracellular delivery, and increase biological activity. Thus, this review offers a deep look into curcumin-loaded nanocarriers intended for the treatment of leishmaniasis.

An update on lipid-based nanodrug delivery systems for leishmaniasis treatment

Lipid-based nanodrug delivery systems hold considerable promise in therapeutic intervention for leishmaniasis by enhancing drug solubility and targeted delivery.

Current Applications of Plant-Based Drug Delivery Nano Systems for Leishmaniasis Treatment

Leishmania is a trypanosomatid that causes leishmaniasis. It is transmitted to vertebrate hosts during the blood meal of phlebotomine sandflies. The clinical manifestations of the disease are associated with several factors, such as the Leishmania species, virulence and pathogenicity, the host-parasite relationship, and the host's immune system. Although its causative agents have been known and studied for decades, there have been few advances in the chemotherapy of leishmaniasis. The urgency of more selective and less toxic alternatives for the treatment of leishmaniasis leads to research focused on the study of new pharmaceuticals, improvement of existing drugs, and new routes of drug administration. Natural resources of plant origin are promising sources of bioactive substances, and the use of ethnopharmacology and folk medicine leads to interest in studying new medications from phytocomplexes. However, the intrinsic low water solubility of plant derivatives is an obstacle to developing a therapeutic product. Nanotechnology could help overcome these obstacles by improving the availability of common substances in water. To contribute to this scenario, this article provides a review of nanocarriers developed for delivering plant-extracted compounds to treat clinical forms of leishmaniasis and critically analyzing them and pointing out the future perspectives for their application.

Hybrid Lipid/Clay Carrier Systems Containing Annatto Oil for Topical Formulations

Nanocomposites formed by clay and lipid carriers (NLCs) show a high potential for providing controlled release and specific delivery of bioactive molecules and have recently gained attention in the pharmaceutical sector due to their ability to transport hydrophilic and hydrophobic drugs. Recent studies have recognized the biological activity of the oil of Bixa orellana L. (AO) with regards to its healing, antioxidant, antibacterial, and anti-leishmanial properties. Therefore, the purpose of this study is the preparation and characterization of hybrid systems based on lipid nanocarriers and laponite for the delivery of AO. NLCs were prepared by the fusion-emulsification method, using cetyl palmitate (CP) or myristyl myristate (MM), AO, and Poloxamer 188. The morphology, hydrodynamic diameters, zeta potential (ZP), polydispersity index (PDI), thermal analysis, X-ray diffraction analysis (XRD), viscosity behavior, and cytotoxicity testing of the hybrid systems were performed. The thermal study and X-ray diffraction analyses (XRD) revealed polymorphic structural changes compatible with the amorphization of the material. Rheological assays highlighted a typical pseudoplastic behavior in all systems (MM and CP with LAP). The hybrid systems’ morphology, size diameters, and PDIs were similar, preset spherical and monodisperse structures (≈200 nm; <0.3), without significant change up to sixty days. The ZP values differed from each other, becoming higher with increasing AO concentration. XEDS spectra and elemental X-ray maps show peaks of lipids (organic components, C and O) and inorganic components O, Mg, and Si. All samples showed cell viability above 60%. The results indicated a stable, biocompatible hybrid system that can be an alternative for topical application.