Treating leishmaniasis in Amazonia: A review of ethnomedicinal concepts and pharmaco-chemical analysis of traditional treatments to inspire modern phytotherapies

Antiprotozoal potential of Vismia species (Hypericaceae), medicinal plants used to fight cutaneous leishmaniasis

ETHNOPHARMACOLOGICAL RELEVANCE

Species of Vismia (Hypericaceae), known in Brazil as "lacre", are commonly used in traditional Amazonian medicine for the treatment of skin lesions, including those caused by Leishmania infection.

AIM OF THE STUDY

Hexane extracts from the leaves of Vismia cayennensis, V. gracilis, V. sandwithii and V. guianensis, as well as from the fruits of the latter, in addition to the anthraquinones vismiaquinone, physcion and chrysophanol isolated from these species were explored for their anti-promastigote and anti-amastigote activity on Leishmania amazonensis.

MATERIALS AND METHODS

Extracts were prepared by static maceration with n-hexane. The compounds, isolated by chromatographic techniques, were identified by spectroscopic methods (1H and 13C NMR). Promastigotes of L.amazonensis were incubated with hexane extracts (1-50 μg/mL) or anthraquinones (1-50 μM) and the parasite survival analyzed. The action of compounds on reactive oxygen species (ROS) production, mitochondrial membrane potential, and membrane integrity of promastigotes were evaluated by flow cytometer, and the cytotoxicity on mammalian cells using MTT assay. Furthermore, the activity of compounds against amastigotes and nitric oxide production were also investigated.

RESULTS

Vismiaquinone and physcion were obtained from the leaves of V. guianensis. Physcion, as well as chrysophanol, were isolated from V. sandwithii. Vismia cayennensis and V. gracilis also showed vismiaquinone, compound detected in lower quantity in the fruits of V. guianensis. All extracts were active against the parasite, corroborating the popular use. The greatest activity against promastigotes was achieved with V. guianensis extract (IC50 4.3 μg/mL), precisely the most used Vismia species for treating cutaneous leishmaniasis. Vismiaquinone and physcion exhibited relevant activity with IC50 12.6 and 2.6 μM, respectively. Moreover, all extracts and anthraquinones tested induced ROS production, mitochondrial dysfunction, membrane disruption and were able to kill intracellular amastigote forms, being worthy of further in vivo studies as potential antileishmanial drugs.

CONCLUSIONS

The overall data achieved in the current investigation scientifically validate the traditional use of Vismia species, mainly V. guianensis, as an anti-Leishmania agent. Furthermore, the promising results presented here indicate species of Vismia as potentially useful resources of Brazilian flora for the discovery of therapeutic solutions for neglected diseases.

In Vitro Anti-Toxoplasma Activity of Extracts Obtained from Tabebuia rosea and Tabebuia chrysantha: The Role of β-Amyrin

Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii that is highly prevalent worldwide. Although the infection is asymptomatic in immunocompetent individuals, it severely affects immunocompromised individuals, causing conditions such as encephalitis, myocarditis, or pneumonitis. The limited therapeutic efficacy of drugs currently used to treat toxoplasmosis has prompted the search for new therapeutic alternatives. The aim of this study was to determine the anti-Toxoplasma activity of extracts obtained from two species of the genus Tabebuia. Twenty-six extracts, 12 obtained from Tabebuia chrysantha and 14 from Tabebuia rosea, were evaluated by a colorimetric technique using the RH strain of T. gondii that expresses β-galactosidase. Additionally, the activity of the promising extracts and their active compounds was evaluated by flow cytometry. β-amyrin was isolated from the chloroform extract obtained from the leaves of T. rosea and displayed important anti-Toxoplasma activity. The results show that natural products are an important source of new molecules with considerable biological and/or pharmacological activity.

Looking through the lens of social science approaches: A scoping review of leishmaniases and Chagas disease research

Scholars have called for increased attention to sociocultural, economic, historical, and political processes shaping Neglected Tropical Diseases (NTDs) ecology. We conducted a scoping review to identify major research themes and the knowledge gaps in social science literature in leishmaniases or Chagas disease (CD). Following the scoping review protocol, we first determined the focus of the review to be centered on identifying research that approaches leishmaniases and CD from social science perspective and was indexed by large, biomedically focused databases. We then searched PubMed and Web of Science using "Leishmaniasis" and "Chagas disease" with "social science" or "anthropology" as search terms. We analyzed 199 articles (123 on leishmaniases and 76 on CD), categorizing them into three main research themes. Sociocultural dimensions of the diseases (leishmaniases=60.2 %; CD=68.4 %) primarily focused on individuals' knowledge, practices, and behaviors, barriers to accessing healthcare (especially in endemic regions), psychosocial effects, stigma, and traditional treatments. Research focused on socioeconomic dimensions of the diseases (leishmaniases=29.3 %; CD=19.7 %) included topics like household characteristics, social capital, and infrastructure access. A final theme, the historical and political contexts of the diseases (Leishmaniases=10.5 %; CD=11.9 %) was less common than other themes. Here, studies consider civil war and the (re)emergence of leishmaniasis, as well as the significance of CD discovery for scientific and public health in Brazil, which is the most common country for research on both leishmaniases and CD that draws on social science approaches. Future directions for research include focusing on how social institutions and economic factors shape diseases education, control measures, healthcare access, and quality of life of people affected by NTDs. Greater attention to social sciences can help mitigate and undo the ways that structural biases have infiltrated biomedicine.

Discourse of the collective subject of river dwellers in the Brazilian Amazon regarding the transmission of knowledge about medicinal plants

This paper investigates the perception of river dwellers in the Brazilian Amazon region about factors that influence the transmission of Traditional Ecological Knowledge (TEK) regarding medicinal plants. Semi-structured interviews were conducted with 43 residents of Vila Franca community (Pará, Brazil). The data were analyzed using the methodological strategy of the Discourse of the Collective Subject. The determining factors in the transmission of TEK were found to be: illness, family coexistence, and necessity, which were represented in the discourses as the most important factors for the acquisition of TEK. In the community context, the locally developed Natural Remedies Project, the beneficial effects of natural remedies, and the lack of resources to purchase allopathic medicines were cited as collaborative factors in the maintenance of TEK. Finally, the most significant determining factors in the decrease or loss of transmission of TEK found in the interviews were: lack of commitment, disbelief, and the valorization of allopathic medicines. A complex network of interactions between the villagers and their natural environment affects the transmission of TEK about medicinal plants. However, we found that the perpetuation of TEK is being threatened by various socio-economic and cultural factors.

Characterization and subchronic oral toxicity of Pentaclethra macroloba (pracaxi) oil in Rattus norvegicus (lin. Wistar)

The trend of replacing antimicrobials as growth promoters in animal nutrition is growing. Functional oils emerge as an alternative because of their richness in bioactive compounds and bioavailability. The present study aims to evaluate the fatty acid profile, antioxidant capacity, composition of phenolic compounds, and toxic capacity in Wistar rats of pracaxi oil (Pentaclethra macroloba). DDPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (Ferric Reducing Antioxidant Power), and ABTS (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) were performed to assess antioxidant capacity. The composition of phenolic compounds was determined by specific reagents. For the evaluation of subchronic oral toxicity, 40 Wistar albino rats (20 males and 20 females) were randomized into 10 groups with different levels of pracaxi oil administered orally. The doses administered were 0, 300, 600, 1200 and 2400 mg/kg (Group 1 to 5 females and Group 6 to 10 males). The animals were submitted to evaluations described in the OECD manual (Guide 407). The analytical results showed that pracaxi oil has different fatty acids in its chemical composition: oleic, linoleic, arachidic, and behenic acids, which account for more than 90% of its composition. In a smaller percentage, lauric acid (0.17%), myristic (0.09%), palmitic (1.49%), stearic (3.45%), and linolenic acid (1.39%) were also found. According to the results of the antioxidant tests, pracaxi oil has a high antioxidant capacity and is a product with a high presence of phenolic compounds. Regarding the toxicity assessment, there were no alterations in the clinical signs and weight of organs. However, in histology, there were mild alterations of a possible toxic process with the increase in the oil dose. This research is extremely valuable since pracaxi oil is a product with little information about its potential use in animal nutrition.

Treating leishmaniasis in Amazonia, part 2: Multi-target evaluation of widely used plants to understand medicinal practices

ETHNOPHARMACOLOGICAL RELEVANCE

Leishmaniasis are widely distributed among tropical and subtropical countries, and remains a crucial health issue in Amazonia. Indigenous groups across Amazonia have developed abundant knowledge about medicinal plants related to this pathology.

AIM OF THE STUDY

We intent to explore the weight of different pharmacological activities driving taxa selection for medicinal use in Amazonian communities. Our hypothesis is that specific activity against Leishmania parasites is only one factor along other (anti-inflammatory, wound healing, immunomodulating, antimicrobial) activities.

MATERIALS AND METHODS

The twelve most widespread plant species used against leishmaniasis in Amazonia, according to their cultural and biogeographical importance determined through a wide bibliographical survey (475 use reports), were selected for this study. Plant extracts were prepared to mimic their traditional preparations. Antiparasitic activity was evaluated against promastigotes of reference and clinical New-World strains of Leishmania (L. guyanensis, L. braziliensis and L. amazonensis) and L. amazonensis intracellular amastigotes. We concurrently assessed the extracts immunomodulatory properties on PHA-stimulated human PBMCs and RAW264.7 cells, and on L. guyanensis antigens-stimulated PBMCs obtained from Leishmania-infected patients, as well as antifungal activity and wound healing properties (human keratinocyte migration assay) of the selected extracts. The cytotoxicity of the extracts against various cell lines (HFF1, THP-1, HepG2, PBMCs, RAW264.7 and HaCaT cells) was also considered. The biological activity pattern of the extracts was represented through PCA analysis, and a correlation matrix was calculated.

RESULTS

Spondias mombin L. bark and Anacardium occidentale L. stem and leaves extracts displayed high anti-promatigotes activity, with IC₅₀ ≤ 32 μg/mL against L. guyanensis promastigotes for S. mombin and IC₅₀ of 67 and 47 μg/mL against L. braziliensis and L. guyanensis promastigotes, respectively, for A. occidentale. In addition to the antiparasitic effect, antifungal activity measured against C. albicans and T. rubrum (MIC in the 16-64 μg/mL range) was observed. However, in the case of Leishmania amastigotes, the most active species were Bixa orellana L. (seeds), Chelonantus alatus (Aubl.) Pulle (leaves), Jacaranda copaia (Aubl.) D. Don. (leaves) and Plantago major L. (leaves) with IC₅₀ < 20 μg/mL and infection rates of 14-25% compared to the control. Concerning immunomodulatory activity, P. major and B. orellana were highlighted as the most potent species for the wider range of cytokines in all tested conditions despite overall contrasting results depending on the model. Most of the species led to moderate to low cytotoxic extracts except for C. alatus, which exhibited strong cytotoxic activity in almost all models. None of the tested extracts displayed wound healing properties.

CONCLUSIONS

We highlighted pharmacologically active extracts either on the parasite or on associated pathophysiological aspects, thus supporting the hypothesis that antiparasitic activities are not the only biological factor useful for antileishmanial evaluation. This result should however be supplemented by in vivo studies, and attracts once again the attention on the importance of the choice of biological models for an ethnophamacologically consistent study. Moreover, plant cultural importance, ecological status and availability were discussed in relation with biological results, thus contributing to link ethnobotany, medical anthropology and biology.

Ethnobotanical and antimicrobial activities of the Gossypium (Cotton) genus: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The Malvaceae family, an important group of plants that have the Gossypium (cotton) genus has been used in folk medicine to treat microbial diseases and symptoms.

AIMS OF THE STUDY

This article aims to understand its ethnobotany expression in communities and scientific elucidation of antimicrobial activities of this genus through literature review.

MATERIALS AND METHODS

The bibliographic survey was carried out from 1999 to 2019 with keywords combinations such as "Gossypium + ethnobotanical", " Gossypium + medicinal ", "Gossypium + the biological activity" in scientific databases as Pubmed, Scopus, Web of Science, DOAJ, Scielo, Bireme.

RESULTS

After data analysis, we found that the Gossypium genus, specifically Gossypium hirsutum, G. barbadense, G. herbaceum, G. arboreum are the species most cited in the treatment of microbial diseases and symptoms in communities all over the world. In light of scientific elucidation of biological activities, the Gossypium genus has been used to treat protozoal, bacterial, fungal, and viral diseases.

CONCLUSIONS

The review demonstrated that the Gossypium genus is a promising source of biological activities against microbial diseases, especially in the treatment of protozoal diseases like malaria.

Migrant Pharmacopoeias: An Ethnobotanical Survey of Four Caribbean Communities in Amazonia (French Guiana)

French Guiana is an overseas French department in South America at the margin of the Amazon basin. Its population is characterized by an important number of cultural groups. Many inhabitants originate from the Caribbean (mostly Saint Lucia, Martinique, Guadeloupe, Haiti, and the Dominican Republic). The objectives of this study were to present an overview of the main uses of plants among the Caribbean populations in French Guiana, and how they contribute to the dynamics of plant-based practices, in order to provide insights into ethnobotanical convergences, divergences, and hybridizations (such as the importation of new species and associated practices, and the adoption of Amazonian species by Caribbean people). Interviews and botanical voucher collections were conducted throughout the coastal area of French Guiana. Sixteen Saint Lucian, nineteen Haitian, eighteen French Caribbean, and twelve Dominican informants were interviewed during the fieldwork. Altogether they use 212 botanical species. Some plants have recently been imported directly from the Caribbean, while adaptations have also taken place: some species that do not exist locally are abandoned while Amazonian species are integrated to form hybrid pharmacopoeias. The phytotherapies of these communities in French Guiana are still conserved as consistent sets of knowledge, although they tend to blend through an ongoing process of hybridization.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12231-021-09529-0.

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.

Caryocar coriaceum Wittm. fruit extracts as Leishmania inhibitors: in-vitro and in-silico approaches

Leishmaniasis is a group of neglected diseases caused by parasites of the Leishmania genus. The treatment of Leishmaniasis represents a great challenge, because the available drugs present high toxicity and none of them is fully effective. Caryocar is a botanical genus rich in phenolic compounds, which leaves extracts have already been described by its antileishmanial action. Thus, we investigated the effect of pulp and peel extracts of the Caryocar coriaceum fruit on promastigote and amastigote forms of Leishmania amazonensis. Both extracts had antipromastigote effect after 24, 48, and 72 h, and this effect was by apoptosis-like process induction, with reactive oxygen species (ROS) production, damage to the mitochondria and plasma membrane, and phosphatidylserine exposure. Knowing that the fruit extracts did not alter the viability of macrophages, we observed that the treatment reduced the infection of these cells. Thereafter, in the in vitro infection context, the extracts showed antioxidant proprieties, by reducing NO, ROS, and MDA levels. Besides, both peel and pulp extracts up-regulated Nrf2/HO-1/Ferritin expression and increase the total iron-bound in infected macrophages, which culminates in a depletion of available iron for L. amazonensis replication. In silico, the molecular modeling experiments showed that the three flavonoids presented in the C. coriaceum extracts can act as synergistic inhibitors of Leishmania proteins, and compete for the active site. Also, there is a preference for rutin at the active site due to its greater interaction binding strength.

Phytotherapies in motion: French Guiana as a case study for cross-cultural ethnobotanical hybridization

BACKGROUND

French Guiana is characterized by a very multicultural population, made up of formerly settled groups (Amerindians, Maroons, Creoles) and more recent migrants (mostly from Latin America and the Caribbean). It is the ideal place to try to understand the influence of intercultural exchanges on the composition of medicinal floras and the evolution of phytotherapies under the effect of cross-culturalism.

METHODS

A combination of qualitative and quantitative methods was used. Semi-directive interviews were conducted in 12 localities of French Guiana's coast between January 2016 and June 2017, and the responses to all closed questions collected during the survey were computerized in an Excel spreadsheet to facilitate quantitative processing. Herbarium vouchers were collected and deposited at the Cayenne Herbarium to determine Linnaean names of medicinal species mentioned by the interviewees. A list of indicator species for each cultural group considered was adapted from community ecology to this ethnobiological context, according to the Dufrêne-Legendre model, via the "labdsv" package and the "indval" function, after performing a redundancy analysis (RDA).

RESULTS

A total of 205 people, belonging to 15 distinct cultural groups, were interviewed using semi-structured questionnaires. A total of 356 species (for 106 botanical families) were cited. We observed that pantropical and edible species hold a special place in these pharmacopeias. If compared to previous inventories, 31 recently introduced species can be counted. Furthermore, this study shows that the majority of the plants used are not specific to a particular group but shared by many communities. However, despite this obvious cross-culturalism of medicinal plants between the different cultural communities of French Guiana, divergent trends nevertheless appear through the importance of 29 indicator/cultural keystone species in 10 cultural groups. Finally, we have emphasized that the transmission of herbal medicine's knowledge in French Guiana is mainly feminine and intra-cultural.

CONCLUSION

French Guianese medicinal flora is undoubtedly related to the multiple cultures that settled this territory through the last centuries. Cultural pharmacopeias are more hybrid than sometimes expected, but cultural keystone species nevertheless arise from a common background, allowing to understand, and define, the relationships between cultural groups.

Astronium fraxinifolium Schott Exerts Leishmanicidal Activity by Providing a Classically Polarized Profile in Infected Macrophages

BACKGROUND

Leishmania braziliensis is prevalent in Latin American countries, including Brazil. It causes cutaneous and mucocutaneous leishmaniasis, leading to high morbidity, and has a low cure rate. Treatment is based on pentavalent antimonials; nonetheless, there are problems related to high toxicity, high cost, and parasitic resistance. Discovery of new leishmanicidal drugs without these limitations and that stimulate the cellular immune response is necessary.

PURPOSE

The present work evaluates whether Astronium fraxinifolium Schott exerts leishmanicidal activity against L. braziliensis by providing a classically polarized profile in infected macrophages.

METHODS

For the evaluation of the A. fraxinifolium Schott leishmanicidal activity, amastigote cell death was demonstrated in infected RAW 267.4 macrophages treated with an ethanolic extract from the plant sapwood (EEAF). For the evaluation of the EEAF capacity in providing a classically polarized profile in infected macrophages, the following analyses were done: detection of LAMP-1 protein by the baculovirus technology, measurement of superoxide anion by the NBT testing, quantification of TNF-α, IL-12p40, IL-10, IL-4, and TGF-β by sandwich-type enzyme immune assays, and iNOS and COX-2 expression by RT-PCR technique.

RESULTS

The EEAF significantly reduced amastigote counts inside the cells. Vacuoles were visualized in infected and treated cells before and after May-Grünwald-Giemsa staining. A strong LAMP-1 protein fluorescence revealed phagosome maturation in infected cells treated with the EEAF. No production of superoxide was visualized in infected cells treated with the plant material. Nonetheless, high levels of TNF-α, IL-12p40, and IL-10 were found in cell supernatants, but reduced levels of TGF-β and no IL-4 production. We identified augmented mRNA expression for COX-2, but no expression of iNOS mRNA.

CONCLUSION

Our results demonstrated that A. fraxinifolium induced a classically polarized profile in infected macrophages but also provided a less harmful environment by stimulating the production of certain anti-inflammatory mediators, such as IL-10.

An NMR-Based Chemometric Strategy to Identify Leishmania donovani Nucleoside Hydrolase Inhibitors from the Brazilian Tree Ormosia arborea

Nucleoside hydrolases are a strategic target for the development of drugs to treat leishmaniasis, a neglected disease that affects 700 thousand to one million people annually. The present study aimed to identify Leishmania donovani nucleoside hydrolase (LdNH) inhibitors from the leaves of Ormosia arborea, a tree endemic to Brazilian ecosystems, through a strategy based on ¹H NMR analyses and chemometrics. The aqueous EtOH extract of O. arborea leaves inhibited LdNH activity by 95%. The extract was fractionated in triplicate (13 in each step, making a total of 39 fractions). Partial least squares discriminant analysis (PLS-DA) was used to correlate the ¹H NMR spectra of the fractions with their LdNH inhibitory activity and thus to identify the spectral regions associated with the bioactivity. The strategy aimed at isolating the probable bioactive substances and led to two new A-type proanthocyanidins, linked to a p-coumaroyl unit (1 and 2), which appeared as noncompetitive inhibitors of LdNH (IC₅₀: 28.2 ± 3.0 μM and 25.6 ± 4.1 μM, respectively). This study confirms the usefulness of the NMR-based chemometric methods to accelerate the discovery of drugs from natural products.

Cytotoxic and cytostatic effects of four Annonaceae plants on human cancer cell lines

Several species of the Annonaceae plants have been used as complementary medicine for cancer-associated illnesses in some ethnic groups of northern Thailand. This study investigated the cytotoxic and cytostatic activity of methanolic extracts derived from the stems of these plants, including Uvaria longipes (Craib) L.L.Zhou, Y.C.F.Su & R.M.K.Saunders, Artabotrys burmanicus A.DC, Marsypopetalum modestum (Pierre) B.Xue & R.M.K.Saunders, and Dasymaschalon sp. Cell death induction of seven human cancer cell lines and cell cycle analyses were assessed by Annexin V and/or propidium iodide (PI) staining and analyzed by flow cytometry. Treatment of cancer cell lines with the extract of four Annonaceae plants resulted in various cytotoxic activities depending on cell type. The extract of U. longipes exhibited the highest cytotoxic activity capable of inducing cell death of several cancer cell lines, particularly against hepatocellular carcinoma cell lines (HepG2 and Hep3B). This extract was capable of inducing cell cycle arrest at the SubG1 phase. Phytochemical screening of all the extracts revealed the presence of alkaloids, sterols, tannins, anthraquinone glycoside, coumarin, and flavonoids. Determination of active compounds by high-performance liquid chromatography standards revealed bullatacin and asiminecin in all the extracts. The extract of Annonaceae stem or its compounds may provide an opportunity for the development of new therapies against cancer.

The historical development of pharmacopoeias and the inclusion of exotic herbal drugs with a focus on Europe and Brazil

ETHNOPHARMACOLOGICAL RELEVANCE

In spite of the rich bio-cultural diversity found in the Neotropics relatively few herbal drugs native to South America are included in the global pharmacopoeia.

MATERIAL AND METHODS

In the attempt to historically explain the inclusion of herbal drugs into official pharmacopoeias we consider the disparate epidemiology and cultural evolution of the New and the Old World. We then trace the development of pharmacopoeias and review forces that worked towards and against the synchronization of pharmacopoeias and highlight the role of early chemical and pharmacological studies in Europe. Finally, we compare the share of exotic and native herbal drug species included in the Brazilian Pharmacopoeia with the share of exotic and native species included in the European Pharmacopoeia as well as those used for products registered with ANVISA.

RESULTS

The domination of Eurasian herbal drugs in the European Pharmacopoeia seems to be conditioned by the geographical extension of Eurasia, which facilitated the interchange of materia medica and the creation of a consensus of use since ancient times. At the time of the Conquest the epidemiology of the Amerindian populations resembled that of pre-agriculturalist societies while no written consensus around efficacious medicine existed. Subsequently, introduced and well-tried plant species of the Old World gained therapeutic importance in the New World.

CONCLUSION

The research focus in Europe and the US resulted in a persistence of herbal drugs with a historic importance in the European and US pharmacopoeias, which gained a status as safe and efficacious. During the last decades only few ethnopharmacological field-studies have been conducted with indigenous Amerindian groups living in the Brazilian Amazon, which might be attributable to difficulties in obtaining research permissions. Newly adopted regulations regarding access to biodiversity and traditional knowledge as well as the simplified procedure for licencing herbal medicinal products in Brazil prospects an interesting future for those aiming at developing herbal medicine based on bio-cultural diversity and respecting the protocols regulating benefit sharing.

Local anti-inflammatory activity: Topical formulation containing Kalanchoe brasiliensis and Kalanchoe pinnata leaf aqueous extract

Kalanchoe brasiliensis and Kalanchoe pinnata are used interchangeably in traditional medicine in the treatment of wound healing. In this context, the objective of the present study was to evaluate the local anti-inflammatory activity of a topical formulation containing aqueous extract of both species. The in vivo model used was ear edema induced by croton oil and paw edema induced by carrageenan. The Swiss mice treatments use formulations containing aqueous extract at different concentrations (1.25%, 2.5%, and 5%) or dexamethasone (1 mg/g), all administered topically and immediately after edema induction. The treatment with formulations containing aqueous extract of both species reduced ear and paw edema, besides that, the decrease in edema was evidenced by reduction of myeloperoxidase activity, IL-1β, and TNF-α levels and increase IL-10 levels. In conclusion, the two species showed local anti-inflammatory activity; however K. brasiliensis showed a better result in both edematogenic models since it had activity in the lowest concentration.

Efficacy of lapachol on treatment of cutaneous and visceral leishmaniasis

Leishmaniasis is one of the most important neglected diseases worldwide. It is a life-threatening disease and causes significant morbidity, long-term disability, and early death. Treatment involves disease control or use of intervention measures, although the currently used drugs require long-lasting therapy, and display toxicity and reduced efficacy. The use of natural products isolated from plants, such as lapachol, an abundant naphthoquinone naturally occurring in South American Handroanthus species (Tabebuia, Bignoniaceae), is a promising option for the treatment of leishmaniasis. In this study, we investigated the leishmanicidal activity of lapachol in vitro and in vivo against Leishmania infantum and L. amazonensis, causative agents of visceral and cutaneous leishmaniasis, respectively. Low cytotoxicity in HepG2 cells (3405.8 ± 261.33 μM), good anti-Leishmania activity, and favorable selectivity indexes (SI) against promastigotes of both L. amazonensis (IC₅₀ = 79.84 ± 9.10 μM, SI = 42.65) and L. infantum (IC₅₀ = 135.79 ± 33.04 μM, SI = 25.08) were observed. Furthermore, anti-Leishmania activity assays performed on intracellular amastigotes showed good activity for lapachol (IC₅₀ = 191.95 μM for L. amazonensis and 171.26 μM for L. infantum). Flow cytometric analysis demonstrated that the cytotoxic effect of lapachol in Leishmania promastigotes was caused by apoptosis-like death. Interestingly, the in vitro leishmanicidal effect of lapachol was confirmed in vivo in murine models of visceral and cutaneous leishmaniasis, as lapachol (25 mg/kg oral route for 24 h over 10 days) was able to significantly reduce the parasitic load in skin lesions, liver, and spleen, similar to amphotericin B, the reference drug. These results reinforce the therapeutic potential of lapachol, which warrants further investigations as an anti-leishmaniasis therapeutic.

Carapa guianensis Aublet (Andiroba) Seed Oil: Chemical Composition and Antileishmanial Activity of Limonoid-Rich Fractions

Leishmaniasis is a complex of diseases caused by protozoa of the genus Leishmania and affects millions of people around the world. Several species of plants are used by traditional communities for the treatment of this disease, among which is Carapa guianensis Aubl. (Meliaceae), popularly known as andiroba. The objective of the present work was to conduct a chemical study of C. guianensis seed oil and its limonoid-rich fractions, with the aim of identifying its secondary metabolites, particularly the limonoids, in addition to investigating its anti-Leishmania potential. The chemical analyses of the C. guianensis seed oil and fractions were obtained by electrospray ionization mass spectrometry (ESI-MS). The cytotoxic activity was tested against peritoneal macrophages, and antileishmanial activity was evaluated against promastigotes and intracellular amastigotes of Leishmania amazonensis. All the C. guianensis seed oil samples analyzed exhibited the same pattern of fatty acids, while the limonoids 7-deacetoxy-7-hydroxygedunin, deacetyldihydrogedunin, deoxygedunin, andirobin, gedunin, 11β-hydroxygedunin, 17-glycolyldeoxygedunin, 6α-acetoxygedunin, and 6α,11β-diacetoxygedunin were identified in the limonoid-rich fractions of the oil. The C. guianensis seed oil did not exhibit antileishmanial activity, and cytotoxicity was higher than 1000 μg/mL. Three limonoid-rich oil fractions demonstrated activity against promastigotes (IC50 of 10.53±0.050, 25.3±0.057, and 56.9±0.043μg/mL) and intracellular amastigotes (IC50 of 27.31±0.091, 78.42±0.086, and 352.2±0.145 μg/mL) of L. amazonensis, as well as cytotoxicity against peritoneal macrophages (CC50 of 78.55±1.406, 139.0±1.523, and 607.7±1.217 μg/mL). The anti-Leishmania activity of the limonoid-rich fractions of C. guianensis can be attributed to the limonoids 11β-hydroxygedunin and 6α,11β-diacetoxygedunin detected in the chemical analysis.

Revisiting the linkage between ethnomedical use and development of new medicines: A novel plant collection strategy towards the discovery of anticancer agents

The Vietnam-Laos International Cooperative Biodiversity Group (ICBG) based at the University of Illinois at Chicago (UIC) catalyzed a country-wide network of medicinal plant preserves (MPP) and medicinal biodiversity preserves (MBP) now established in ten provinces of the Lao People's Democratic Republic (Lao PDR), which are relied upon as protected sources of ethnomedicines for local villagers and traditional healers. In collaboration with the Lao PDR's Institute of Traditional Medicine (ITM), our ongoing P01 Program Project (Ohio State University) examined the anticancer bioprospecting potential for two of the most exhaustively inventoried of these sites: the Bolikhamxay MPP and the Xiengkhouang MBP. Guided by prior voucher specimens sourced from these preserves with an overwhelming emphasis on plants employed in traditional medicine, 201 distinct samples from 96 species were collected along with proper herbarium documentation. Aliquots of these plant samples were extracted in azeotropic ethanol and evaporated to dryness for initial biological evaluation. In six samples from six different species (2.99% of the collected samples, 6.25% of taxa) it was observed that extracts exhibited notable cytotoxicity against HT-29 colon adenocarcinoma cells. The wisdom behind the utilization of HT-29 cells in this preliminary biological screen is discussed. Furthermore, comparison of screening results based on longstanding considerations and ideological underpinnings of ethnobotanical vs. "random" biodiversity-based collection approaches is detailed herein. The results of this interdisciplinary study support the hypothesis that, by privileging the initial sample set in terms of human safety and pharmacological activity, ethnobotanically driven collection for biological screening efforts can produce leads unprecedented by the strict traditional usages of plants.