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Background/Objectives: Leishmaniasis, a neglected disease caused by Leishmania spp. including L. amazonensis , urgently requires new treatments. Polyalthic acid (PA), a natural diterpene from Copaifera spp., has previously demonstrated significant antiparasitic potential. This study evaluated the leishmanicidal effects of polyalthic acid (PA), alone and with amphotericin B (AmpB), on L. amazonensis promastigote and amastigote forms. Results: PA showed significant activity against promastigotes, with 50% effective concentration (EC 50 ) values of 2.01 μM at 24 h and an EC 50 of 3.22 μM against amastigotes after 48 h. The PA and AmpB combination exhibited a synergistic effect on both forms without inducing cytotoxicity or hemolysis. Morphological changes in promastigotes, including vacuole formation and cell rounding, were more pronounced with the combination. Conclusions: These findings suggest that PA and AmpB together could form a promising new treatment strategy against Leishmania infections, offering enhanced efficacy without added toxicity.

We report the chemical composition of the crude leaf extracts obtained from Stizophyllum perforatum (Cham.) Miers (Bignoniaceae), a simple high-performance liquid chromatography-diode array detection (HPLC-DAD) method based on mangiferin as an internal standard to quantify verbascoside, and the verbascoside acute oral toxicity and antileishmanial activity. HPLC-high-resolution mass spectrometry-DAD (HPLC-HRMS-DAD) analyses of the crude ethanol S. perforatum leaf extracts (CE-1 and CE-2) revealed that verbascoside was the major constituent in both extracts. CE-1 was purified, and verbascoside and casticin, among other compounds, were isolated. The developed HPLC-DAD method was validated and met the required standards. Investigation of the CE-2 acute toxicity indicated a lethal dose (LD 50 ) greater than 2,000 mg/kg of body weight. Both CE-1 and CE-2 exhibited antileishmanial activity. The isolated compounds, verbascoside and casticin, also displayed antileishmanial activity with effective concentrations (IC 50 ) of 6.23 and 24.20 µM against promastigote forms and 3.71 and 18.97 µM against amastigote forms of Leishmania amazonensis , respectively, but they were not cytotoxic to J774A.1 macrophages. Scanning electron microscopy of the L. amazonensis promastigotes showed that the parasites became more rounded and that their plasma membrane was altered in the presence of verbascoside. Additionally, transmission electron microscopy demonstrated that vacuoles emerged, lipids accumulated, kinetoplast size increased, and interstitial extravasation occurred in L. amazonensis promastigotes exposed to verbascoside. These findings suggest that S. perforatum is a promising candidate for further in vivo investigations against L. amazonensis ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Alves, Ozelin, Magalhães, Candido, Gimenez, Silva, Cunha, Januário, Tavares, Magalhães and Pauletti.)

Propolis is a natural product of great economic and pharmacological importance. The flora surrounding the bee communities is a determining factor in the composition of propolis and therefore in its biological and medicinal properties. Brown propolis is one of the most important types of propolis in Brazil, produced in the southeastern region. The ethanolic extract of a brown propolis sample from Minas Gerais state was chemically characterized for the subsequent development of a RP-HPLC method, validated according to the standards of regulatory agencies. The leishmanicidal activity of this extract was assessed. The brown propolis was characterized by the presence of chemical markers reported on green propolis such as ferulic acid, coumaric acid, caffeic acid, cinnamic acid, baccharin, artepillin and drupanin, indicating a probable origin on Baccharis dracunculifolia. The developed method agreed with the parameters established by the validation guidelines, then proved to be reliable for the analysis of this type of propolis. The brown propolis displayed significant activity against Leishmania amazonensis with IC 50 values of 1.8 and 2.4 μg/ml against the promastigote and amastigote forms, respectively. The studied propolis exhibited promising evidence for use as a natural source against L. amazonensis., (© 2023 John Wiley & Sons Ltd.)

Chagas disease is a neglected tropical disease that affects more than 8 million people. Although there are therapies against this disease, the search for new drugs is important because the current treatments show limited effectiveness and high toxicity. In this work, eighteen dihydrobenzofuran-type neolignans (DBNs) and two benzofuran-type neolignans (BNs) were synthesized and evaluated against amastigote forms of two Trypanosoma cruzi strains. The in vitro cytotoxicity and hemolytic activity of the most active compounds were also evaluated and their relationships with T. cruzi tubulin DBNs were investigated by an in silico approach. Four DBNs demonstrated activity against the T. cruzi Tulahuen lac-Z strain (IC 50 from 7.96 to 21.12 µM), and DBN 1 exhibited the highest activity against the amastigote forms of the T. cruzi Y strain (IC 50 3.26 μM). Compounds 1 - 4 showed CC 50 values higher than antitrypanosomal activities, except for DBN 3 . All DBNs with antitrypanosomal activity demonstrated CH 50 higher than 100 µM. The in silico results indicated that DBNs 1 , 2 , and 4 are capable of destabilizing the dynamics of the tubulin-microtubule from the vinca site. These compounds displayed promising in vitro activity against T. cruzi , especially compound 1 , and can be considered molecular prototypes for the development of new antiparasitic drugs.

This article aims to investigate volatile constituents and antiacetylcholinesterase, antileishmanial and antiproliferative activities of hexane extracts from Capsicum chinense fruit (unripe bode pepper 'HE-UB' and ripe little beak pepper 'HE-RB'). HE-UB and HE-RB were screened by the microplate assay method to determine their antiacetylcholinesterase activity. Both exhibited inhibitory potential, i. e., IC 50 = 41.5 and 20.3 µg/mL, respectively. HE-UB (IC 50 = 67.19 µg/mL) and HE-RB (IC 50 = 38.16 µg/mL) exhibited antileishmanial activity against promastigote forms of Leishmania (Leishmania) amazonensis . In addition, HE-UB and HE-RB demonstrated cytotoxic activity against different human tumor cell lines with IC 50 ranging from 325.40 to 425.0 µg/mL. Both GC-FID and GC-MS analyses revealed that the major component in both extracts was E -caryophyllene. In short, HE-RB was more satisfactory than HE-UB in all in vitro activities under evaluation. These findings may be used as initial data for further studies of Capsicum species.

Spiranthera odoratissima A. St.-Hil. (Rutaceae) has been popularly used against abdominal pain and rheumatism. This study aimed at extracting hexane from S. odoratissima (HE-SO) leaves to identify and quantify its volatile compounds by GC-MS and GC-FID and to evaluate its antifungal, antileishmanial and antibacterial activities in vitro . HE-SO exhibited antileishmanial activity against promastigote forms of Leishmania (Leishmania) amazonensis (IC 50 = 38.16 µg/mL) and was moderately active against Xylella fastidiosa (MIC = 100 µg/mL). HE-SO also showed remarkable antifungal potential against six strains of Candida species, i. e., C. albicans , C. glabrata , C. parapsilosis , C. krusei , C. tropicalis and C. orthopsilosis . The lowest MIC values were between 31.25 and 250 µg/mL. Spathulenol (20.2%), τ-cadinol (11.7%), α-cadinol (9.4%), caryophyllene oxide (9.2%) and isoaromadendrene epoxide (8.2%) were the major components identified in HE-SO. Therefore, results showed that HE-SO has promising antileishmanial and antifungal actions.

Despite the current treatments against Chagas Disease (CD), this vector-borne parasitic disease remains a serious public health concern. In this study, we have explored the in vitro and/or in vivo trypanocidal and cytotoxic activities of the essential oils (EOs) obtained from Dysphania ambrosioides (L.) Mosyakin & Clemants (Amaranthaceae) (DA-EO), Lippia alba (Mill.) N.E. Brown (Verbenaceae) (LA-EO), and Tetradenia riparia (Hochst.) Codd (Lamiaceae) (TR-EO) grown in Brazil Southeast. DA-EO was the most active against the trypomastigote and amastigote forms in vitro; the IC 50 values were 8.7 and 12.2 μg mL -1 , respectively. The EOs displayed moderate toxicity against LLCMK2 cells, but the DA-EO showed high selectivity index (SI) for trypomastigote (SI=33.2) and amastigote (SI=11.7) forms. Treatment with 20 mg/kg DA-EO, LA-EO, or TR-EO for 20 days by intraperitoneal administration reduced parasitemia by 6.36 %, 4.74 %, and 32.68 % on day 7 and by 12.04 %, 27.96 %, and 65.5 % on day 9. These results indicated that DA-EO, LA-EO, and TR-EO have promising trypanocidal potential in vitro, whereas TR-EO has also potential trypanocidal effects in vivo., (© 2021 Wiley-VHCA AG, Zurich, Switzerland.)

Numerous studies have investigated the chemical composition and biological activities of essential oils from different Citrus species fruit peel, leaves and flowers. This paper aims to investigate the chemical composition, larvicidal and antileishmanial activities of essential oil from Citrus reticulata fruit peel (CR-EO). CR-EO was obtained by hydrodistillation in a Clevenger-type apparatus and its chemical composition was analyzed by GC-MS and GC-FID. Limonene (85.7%), ɣ-terpinene (6.7%) and myrcene (2.1%) were identified as its major components. CR-EO showed high activity against promastigote forms of Leishmania amazonensis (IC50 = 8.23 µg/mL). CR-EO also exhibited high larvicidal activity against third instar Aedes aegypti larvae at a lethal concentration (LC50 = 58.35 µg/mL) and 100% mortality at 150 µg/mL. This study suggests, for the first time, the potential use of CR-EO against this important mosquito-borne viral disease caused by the genus Aedes.

Chagas disease is a tropical disease caused by the protozoan parasite Trypanosoma cruzi and currently affects millions of people worldwide. Curcumin (CUR), the major constituent of turmeric spice (dry powder of Curcuma longa L. plant rhizomes and roots), exhibits antiparasitic activity against protozoan parasites in vitro . However, because of its chemical instability, poor cellular uptake and limited bioavailability it is not suitable for clinical use. The objective of this study was to synthesize and evaluate in vitro CUR monoketone analog dibenzalacetone (DBA 1 ) and its non-phenolic, methoxy ( 2-4 ) and chloro ( 5 ) derivatives for better stability and bioavailability against T. cruzi . Diveratralacetone, the tetramethoxy DBA (DBA 3 ), was found to be the CUR analog with most enhanced activity against the amastigote forms of four strains of T. cruzi tested (Brazil, CA-I/72, Sylvio X10/4 and Sylvio X10/7) with 50% inhibitory concentration (IC 50 ) < 10 μM (1.51-9.63 μM) and selectivity index (SI) > 10 (C2C12 non-infected mammalian cells). This was supplemented by time-course assessment of its anti- T. cruzi activity. DBA 1 and its dimethoxy (DBA 2 ) and hexamethoxy (DBA 4 ) derivatives were substantially less active. The inactivity of dichloro-DBA (DBA 5 ) was indicative of the important role played by oxygenated groups such as methoxy in the terminal aromatic rings in the DBA molecule, particularly at para position to form reactive oxygen species essential for anti- T. cruzi activity. Although the DBAs and CUR were toxic to infected mammalian cells in vitro , in a mouse model, both DBA 3 and CUR did not exhibit acute toxicity or mortality. These results justify further optimization and in vivo anti- T. cruzi activity evaluation of the inexpensive diveratralacetone for its potential use in treating Chagas disease, a neglected parasitic disease in economically challenged tropical countries., (© 2021 The Author(s).)

Fractionation of extracts from the culture broth of the marine-derived fungus, Paecilomyces sp. 7A22, resulted in the isolation of the harzialactone A ( HA ), a known compound previously isolated from fungi of marine environments. The chemical structure of HA was determined by spectroscopic analyses. Upon evaluation of HA on antileishmanial assays against Leishmania amazonensis , HA exhibited significant activity against promastigotes forms with IC 50 of 5.25 µg mL -1 and moderate activity against intracellular amastigotes with IC 50 of 18.18 µg mL -1 . This is the first report on the antileishmanial activity of HA , and the effects of HA presented in this work suggest that this class of compounds are suitable for future biological in vitro and in vivo studies for the search of natural products with activity against Leishmania spp. Furthermore, the present results corroborate marine-derived fungi as a promising source of natural products with antiparasitic activity.

Introduction: Propolis is widely used in folk medicine, and many factors can affect its chemical composition, including abiotic factors that can influence plants and bees. Therefore, analytical methods are powerful techniques in the quality control of such products., Objective: Develop and validate an analytical method for quantifying volatile compounds in Brazilian brown propolis, and evaluate its biological activities., Methods: A gas chromatography flame ionisation detector (GC-FID) analytical method was validated, attending the parameters of international validation guidelines as ANVISA 2017 and ICH 2005, for quantification of compounds present in volatile oils from propolis. Evaluation of cytotoxic, antimicrobial, and leishmanicidal activities of the oil., Results: The compounds 1,8-cineole, terpinen-4-ol, α-copaene, β-caryophyllene, γ-muurolene, nerolidol, spathulenol, and γ-palmitolactone were isolated from the volatile fraction of a Brazilian brown propolis and used in the method validation. All the validation parameters of the method were satisfactory. The volatile fraction displayed a significant leishmanicidal activity, with half maximal inhibition concentration (IC 50 ) = 21.3 μg/mL against amastigote forms and IC 50 = 25.1 μg/mL against promastigote forms of Leishmania amazonensis. The oil also displayed an antibacterial effect by inhibiting the growth of Streptococcus mutans and Staphylococcus aureus at 25 μg/mL and 50 μg/mL, respectively, but it was not cytotoxic against AGP-01, He-La and CHO-K1cell lines, with IC 50 > 100 μg/mL., Conclusion: The GC-FID method can be a useful tool in the quality control of propolis material. The southeast brown propolis showed a high chemical complexity in its volatile fraction, which displayed leishmanicidal activity and bactericidal activity., (© 2020 John Wiley & Sons, Ltd.)

The efficacy of Licochalcone A (LicoA) and its two analogs were reported against Leishmania (Leishmania) amazonensis and Leishmania (Leishmania) infantum in vitro , and in experimental model of L. (L.) infantum in vitro . Initially, LicoA and its analogs were screened against promastigote forms of L. (L.) amazonensis . LicoA was the most active compound, with IC 50 values of 20.26 and 3.88 μM at 24 and 48 h, respectively. Against amastigote forms, the IC 50 value of LicoA was 36.84 μM at 48 h. In the next step, the effectivity of LicoA was evaluated in vitro against promastigote and amastigote forms of L. (L.) infantum . Results demonstrated that LicoA exhibited leishmanicidal activity in vitro against promastigote forms with IC 50 values of 41.10 and 12.47 μM at 24 and 48 h, respectively; against amastigote forms the IC 50 value was 29.58 μM at 48 h. Assessment of cytotoxicity demonstrated that LicoA exhibited moderate mammalian cytotoxicity against peritoneal murine macrophages; the CC 50 value was 123.21 μM at 48 h and showed about 30% of hemolytic activity at concentration of 400 μM. L. (L.) infantum- infected hamsters and treated with LicoA at 50 mg/kg for eight consecutive days was able to significantly reduce the parasite burden in both liver and spleen in 43.67 and 39.81%, respectively, when compared with negative control group. These findings suggest that chalcone-type flavonoids can be a promising class of natural products to be considered in the search of new, safe, and effective compounds capable to treat canine visceral leishmaniosis (CVL)., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Souza, de Carvalho, Candido, de Mendonça, Fernanda da Silva, Parreira, Dias, Ambrósio, Arantes, da Silva Filho, Nascimento, Costa, Sairre, Veneziani and Magalhães.)

Solanum paniculatum L. is species whose fruits are widely consumed in Brazil as a tonic beverage with higher content of steroidal saponins. In this work, we developed an analytical method for the quantification of the eight saponins present in the 70 % ethanol extract from the leaves using ultra-high-performance liquid chromatography coupled to mass spectrometry (UHPLC-MS). Besides, the eight spirostanic saponins were screened for in vitro antileishmanial activity against promastigote and amastigote forms of Leishmania (L.) amazonensis. Substances 1, 2 and 3 were found to be the most active compounds, with inhibitory concentration (IC 50 ) values of 8.51 ± 4.38, 10.75 ± 6.85 and 10.45 ± 4.21 μM, respectively, against promastigote forms and effective concentration (EC 50 ) values of >25, 17.73 ± 0.99 and 19.57 ± 0.84 μM, respectively, against amastigote forms. The cytotoxic test with compounds 1-3 evidenced low toxicity in murine macrophage cells, with values above 50 μM at concentration lower than 25 μM. These findings show that saponins 1-3 should be evaluated in further studies for the treatment of cutaneous leishmaniasis., Competing Interests: Declaration of Competing Interest The authors reported no declarations of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Eugenia species have been appreciated for their edible fruits and medicinal properties. This paper aims to investigate the chemical composition and in vitro antileishmanial, antifungal and antiproliferative activities of essential oil from aerial parts of Eugenia pyriformis (EP-EO). The oil showed strong antileishmanial activity against promastigote forms of Leishmania amazonensis (IC 50 = 2.16 µg/mL). It also exhibited high antifungal activity against Malassezia furfur (MIC = 30 µg/mL), which was determined by the broth microdilution method. Its antiproliferative activity was evaluated against the following cells: GM07429A (normal cell), MCF-7 (human breast adenocarcinoma), HeLa (human cervical adenocarcinoma) and M059J (human glioblastoma). Its major constituents, which were determined by GC-FID and GC-MS, were limonene (14.8%), nerolidol (11.0%), α-cadinol (10.3%), caryophyllene oxide (9.9%) and β-pinene (7.1%). These results showed, for the first time, the effectiveness of EP-EO as a natural product which has promising biological activities, a fact that enables its ethnopharmacological use.

Organogels (ORGs) are semi-solid materials, in which an organic phase is immobilized by a three-dimensional network composed of self-organized system, forming the aqueous phase. In this context, lipid-Pluronics (PLs) ORGs form a two-phase system which can be effectively used as skin delivery systems, favoring their permeation across the skin. In this study, we presented the development of ORG skin drug-delivery systems for curcumin (CUR), a liposoluble phenolic pigment extracted from the turmeric rhizome. In special, we designed the formulation compositions in order to carry high amounts of CUR soluble in oleic acid (OA), as organic phase, entrapped into an aqueous phase composed of micellar PL-based hydrogels by associating two polymers with different hydrophilic-lipophilic balances, Pluronic F-127 (PL F-127), and Pluronic L-81 (PL L-81), to enhance the permeation across the skin. Results revealed that the incorporation of PL L-81 favored the CUR incorporation into micelle-micelle interface. CUR insertion into OA-PL F-127/L-81 reduced both G'/G" relationship (∼16 x) and viscosity values (η* ∼ 54 mPa.s, at 32.5°C), disturbing the ORG network structural organization. In vitro permeation assays through Strat-M ® skin-model membranes showed that higher CUR-permeated amounts were obtained for OA-PL F-127/L-81 (4.83 µg.cm -2 ) compared to OA-PL F-127 (3.51 μg.cm -2 ) and OA (2.25 μg.cm -2 ) or hydrogels (∼1.2 μg.cm -2 , p < 0.001). Additionally, ORG formulations presented low cytotoxic effects and evoked pronounced antileishmanial activity (IC 50 < 1.25 µg.ml -1 ), suggesting their potential use as skin delivery systems against Leishmania amazonensis . Results from this study pointed out OA-PL-based ORGs as promising new formulations for possible CUR topical administration., (Copyright © 2019 Vigato, Querobino, de Faria, Candido, Magalhães, Cereda, Tófoli, Campos, Machado, Fraceto, de Sairre and de Araujo.)