Infusions of Aspidosperma nitidum (Apocynaceae) wood bark are used to treat fever and malaria in the Amazon Region. Several species of this family are known to possess indole alkaloids and other classes of secondary metabolites, whereas terpenoids, an inositol and the indole alkaloids harmane-3 acid and braznitidumine have been described in A. nitidum . In the present study, extracts from the wood bark, leaves and branches of this species were prepared for assays against malaria parasites and cytotoxicity testing using human hepatoma and normal monkey kidney cells. The wood bark extracts were active against Plasmodium falciparum and showed a low cytotoxicity in vitro, whereas the leaf and branch extracts and the pure alkaloid braznitidumine were inactive. A crude methanol extract was subjected to acid-base fractionation aimed at obtaining alkaloid-rich fractions, which were active at low concentrations against P. falciparum and in mice infected with and sensitive Plasmodium berghei parasites. Our data validate the antimalarial usefulness of A. nitidum wood bark, a remedy that can most likely help to control malaria. However, the molecules responsible for this antimalarial activity have not yet been identified. Considering their high selectivity index, the alkaloid-rich fractions from the plant bark might be useful in the development of new antimalarials.

The main challenges associated with leishmaniasis chemotherapy are drug toxicity, the possible emergence of resistant parasites, and a limited choice of therapeutic agents. Therefore, new drugs and assays to screen and detect novel active compounds against leishmaniasis are urgently needed. We thus validated Leishmania braziliensis (Lb) and Leishmania infantum (Li) that constitutively express the tandem tomato red fluorescent protein ( tdTomato ) as a model for large-scale screens of anti- Leishmania compounds. Confocal microscopy of Lb and Li::tdTomato revealed red fluorescence distributed throughout the entire parasite, including the flagellum, and flow cytometry confirmed that the parasites emitted intense fluorescence. We evaluated the infectivity of cloned promastigotes and amastigotes constitutively expressing tdTomato , their growth profiles in THP-1 macrophages, and susceptibility to trivalent antimony, amphotericin, and miltefosine in vitro . The phenotypes of mutant and wild-type parasites were similar, indicating that the constitutive expression of tdTomato did not interfere with the evaluated parameters. We applied our validated model to a repositioning strategy and assessed the susceptibility of the parasites to eight commercially available drugs. We also screened 32 natural plant and fungal extracts and 10 pure substances to reveal new active compounds. The infectivity and Glucantime treatment efficacy of BALB/c mice and golden hamsters infected with Lb and Li::tdTomato mutant lines, respectively, were very similar compared to animals infected with wild-type parasites. Standardizing our methodology would offer more rapid, less expensive, and easier assays to screen of compounds against L. braziliensis and L. infantum in vitro and in vivo . Our method could also enhance the discovery of active compounds for treating leishmaniasis.

Honeys can be classified as polyfloral or monofloral and have been extensively studied due to an increased interest in their consumption. There is concern with the correct identification of their flowering, the use of analyses that guarantee their physicochemical quality and the quantification of some compounds such as phenolics, to determine their antioxidant and antimicrobial action. This study aims at botanical identification, physicochemical analyses, and the determination of total polyphenols, chromatographic profile and antiradical and antimicrobial activity of honey from different regions of Minas Gerais. Seven different samples were analyzed for the presence of pollen, and color determination. The physicochemical analyses performed were total acidity, moisture, HMF, reducing sugar, and apparent sucrose. The compound profile was determined by UHPLC/MS, the determination of total phenolics and antiradical activity (DPPH method) were performed by spectrophotometry, and minimum inhibitory and bacterial concentrations were determined for cariogenic bacteria. All honey samples met the quality standards required by international legislation, twenty compounds were detected as the main ones, the polyfloral honey was the only honey that inhibited all of the bacteria tested. Sample M6 (Coffee) was the one with the highest amount of total polyphenols, while the lowest was M4 (Cipó-uva). Regarding the antioxidant activity, M5 (Velame) had the best result and M4 (Cipó-uva) was the one that least inhibited oxidation. Of the polyfloral honeys, there was not as high a concentration of phenolic compounds as in the others. Coffee, Aroeira, Velame and Polyfloral have the best anti-radical actions. Betônica, Aroeira, Cipó-uva and Pequi inhibited only some bacteria. The best bacterial inhibition results are from Polyfloral.

Honey is a natural product of high nutritional and therapeutic value, whose biological properties are closely linked to its botanical origin and chemical composition. This study aimed to characterize avocado honey in terms of botanical origin, physicochemical parameters, phenolic content, antioxidant activity, chemical profile by LC-MS/MS, and antibacterial potential. Melissopalynological analysis revealed 86.21% avocado pollen, allowing classification as monofloral honey. The sample presented amber color and a high total phenolic content (269.79 ± 1.10 mg GAE 100 g⁻¹), values higher than those commonly reported for Brazilian and international honeys. Antioxidant activity, assessed by the DPPH method, confirmed the strong radical-scavenging capacity, consistent with the phenolic profile identified (EC₅₀ 10.250 ± 0.003 mg mL⁻¹). LC-MS/MS analysis allowed the annotation of nine compounds, including caffeine, scopoletin, abscisic acid, and vomifoliol, compounds associated with antioxidant, anti-inflammatory, and metabolic regulatory activities. Although no antibacterial effect was detected against the tested oral bacterial strains, the results highlight the chemical diversity and functional potential of avocado honey. Overall, the findings reinforce the bioactive potential of avocado honey, particularly due to its strong antioxidant capacity and diversity of metabolites, supporting its value as a natural resource of nutritional and therapeutic interest.

Diplopterys pubipetala (Malpighiaceae) is a liana native to the Brazilian Cerrado biome, traditionally used in Ayahuasca preparations. Despite its cultural importance, research on its chemical composition and biological activities, which may have therapeutic potential, is limited. This study investigated the volatile and non-volatile secondary metabolites of D. pubipetala leaves, their antioxidant capacity, and their antibacterial and antifungal activities. Volatile compounds were identified using gas chromatography-mass spectrometry (GC-MS) coupled to solid-phase microextraction (SPME), while non-volatile compounds were annotated using UHPLC-MS/MS-ESI-Q-TOF. Antioxidant capacity was evaluated by DPPH assay, and antimicrobial activity was assessed in vitro against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida species (C. albicans, C. tropicalis, C. glabrata). GC-MS analysis revealed 25 predominant volatile compounds, including ethyl dodecanoate, ethyl tetradecanoate, nonanoic acid, and 5-methylhexan-2-one, with documented antifungal, antioxidant, and antimicrobial activities. The crude extract and ethyl acetate fraction showed strong antioxidant capacity (EC₅₀ 9.83 µg/mL and 6.42 µg/mL, respectively), and antifungal effects were observed against Candida species. This study provides the first comprehensive investigation of the antioxidant capacity and antibacterial and antifungal activities of D. pubipetala, together with a detailed chemical profile of its volatile compounds.