Ethnopharmacological evaluation of medicinal plants used against malaria by quilombola communities from Oriximiná, Brazil

Malaria in a vulnerable population living in quilombo remnant communities in the Brazilian Amazon: a cross-sectional study from 2005-2020

Quilombo remnant communities are areas officially recognized by the Brazilian government as historical communities founded by formerly enslaved individuals. These communities are mostly located in the endemic areas of malaria in the Brazilian Amazon. We retrospectively described the prevalence of malaria among individuals living in 32 recognized quilombo remnant communities in the Baiao and Oriximina municipalities located in the Para State. The number of malaria cases and the Annual Parasitic Incidence (API) recorded by the Brazilian malaria surveillance system (SIVEP-Malaria) from January 2005 to December 2020 were analyzed. We found that all communities registered at least one case over the 16-year period, the most frequent parasitic species being Plasmodium vivax (76.1%). During this period, 0.44% (4,470/1,008,714) of the malaria cases registered in Para State were reported in these quilombo remnant communities, with frequencies of 10.9% (856/7,859) in Baiao municipality and 39.1% (3,614/9,238) in Oriximina municipality, showing that individuals living in these rural communities are exposed to malaria. These data indicate that effective surveillance requires improved measures to identify malaria transmission among vulnerable populations living in quilombo remnant communities in the Brazilian Amazon.

Brazilian plants with antimalarial activity: A review of the period from 2011 to 2022

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria continues to be a serious global public health problem in subtropical and tropical countries of the world. The main drugs used in the treatment of human malaria, quinine and artemisinin, are isolates of medicinal plants, making the use of plants a widespread practice in countries where malaria is endemic. Over the years, due to the increased resistance of the parasite to chloroquine and artemisinin in certain regions, new strategies for combating malaria have been employed, including research with medicinal plants.

AIM

This review focuses on the scientific production regarding medicinal plants from Brazil whose antimalarial activity was evaluated during the period from 2011 to 2022. 2.

METHODOLOGY

For this review, four electronic databases were selected for research: Pubmed, ScienceDirect, Scielo and Periódicos CAPES. Searches were made for full texts published in the form of scientific articles written in Portuguese or English and in a digital format. In addition, prospects for new treatments as well as future research that encourages the search for natural products and antimalarial derivatives are also presented.

RESULTS

A total of 61 publications were encountered, which cited 36 botanical families and 92 species using different Plasmodium strains in in vitro and in vivo assays. The botanical families with the most expressive number of species found were Rubiaceae, Apocynaceae, Fabaceae and Asteraceae (14, 14, 9 and 6 species, respectively), and the most frequently cited species were of the genera Psychotria L. (8) and Aspidosperma Mart. (12), which belong to the families Rubiaceae and Apocynaceae. Altogether, 75 compounds were identified or isolated from 28 different species, 31 of which are alkaloids. In addition, the extracts of the analyzed species, including the isolated compounds, showed a significant reduction of parasitemia in P. falciparum and P. berghei, especially in the clones W2 CQ-R (in vitro) and ANKA (in vivo), respectively. The Brazilian regions with the highest number of species analyzed were those of the north, especially the states of Pará and Amazonas, and the southeast, especially the state of Minas Gerais.

CONCLUSION

Although many plant species with antimalarial potential have been identified in Brazil, studies of new antimalarial molecules are slow and have not evolved to the production of a phytotherapeutic medicine. Given this, investigations of plants of traditional use and biotechnological approaches are necessary for the discovery of natural antimalarial products that contribute to the treatment of the disease in the country and in other endemic regions.

A potential antiviral against COVID-19 obtained from Byrsonima coccolobifolia leaves extract

In this study, we specifically focused on the crude methanolic leaf extract of Byrsonima coccolobifolia, investigating its antifungal potential against human pathogenic fungi and its antiviral activity against COVID-19. Through the use of high-performance liquid chromatography coupled with electrospray ionization ion trap tandem mass spectrometry, direct infusion electrospray ionization ion trap tandem mass spectrometry, and chromatographic dereplication procedures, we identified galloyl quinic acid derivatives, catechin derivatives, proanthocyanidins, and flavonoid glycosides. The broth dilution assay revealed that the methanolic leaf extract of B. coccolobifolia exhibits antifungal activity against Cryptococcus neoformans (IC50 = 4 μg/mL). Additionally, docking studies were conducted to elucidate the interactions between the identified compounds and the central residues at the binding site of biological targets associated with COVID-19. Furthermore, the extract demonstrated an in vitro half-maximum effective concentration (EC50 = 7 μg/mL) and exhibited significant selectivity (>90%) toward SARS-CoV-2.

In Vitro and in Vivo Antimalarial Activity, Cytotoxicity and Phytochemical HRMS2 Profile of Plants from the Western Pará State, Brazilian Amazonia

Ethnopharmacology and botanical taxonomy are valid criteria used to selecting plants for antimalarial bioprospection purposes. Based on these two criteria, ethanol extracts of 11 plants from Santarém City vicinities, Western Pará State, Brazilian Amazonia, had their in vitro antiplasmodial activity against chloroquine-resistant Plasmodium falciparum (W2 clone) assessed by the PfLDH method, whereas their cytotoxicity to HepG2-A16 cells was assessed through MTT assay. Acmella oleracea, Siparuna krukovii and Trema micrantha extracts disclosed the highest rate of parasite growth inhibition (90 %) in screening tests. In vivo antimalarial assays were conducted with these extracts against Plasmodium berghei (NK 65 strain) infected mice. Inhibition rate of parasite multiplication ranged from 41.4 % to 60.9 % at the lowest extract dose (25 mg/kg). HPLC-ESI-HRMS2 analyses allowed the putative identification of alkylamides, fatty acids, flavonoid glycosides and alkaloids in ethanol extracts deriving from these three plant species. Results pointed towards A. oleracea flowers ethanol extract as the most promising potential candidate to preclinical studies aiming the development of antimalarial phytomedicine.

Plectranthus Species with Anti-Inflammatory and Analgesic Potential: A Systematic Review on Ethnobotanical and Pharmacological Findings

The use of medicinal plants to treat inflammatory conditions and painful processes has attracted the attention of scientists and health professionals due to the evidence that natural products can promote significant therapeutic benefits associated with fewer adverse effects compared to conventional anti-inflammatory drugs. The genus Plectranthus is composed of various plants with pharmacological potential, which are used to treat various diseases in traditional communities worldwide. The present study systematically reviewed Plectranthus species with anti-inflammatory and analgesic potential. To this end, a systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. The search was conducted on the following databases: PubMed, ScienceDirect, SciVerse Scopus, and Web of Science. Different combinations of search terms were used to ensure more excellent article coverage. After the selection, a total of 45 articles were included in this review. This study identified twelve Plectranthus species indicated for the treatment of different inflammatory conditions, such as wounds, fever, bronchitis, abscess, asthma, hepatitis, labyrinthitis, tonsillitis, and uterine inflammation. The indications for pain conditions included headache, sore throat, heartburn, menstrual cramp, colic, toothache, stomachache, migraine, chest pain, abdominal pain, local pain, labor pain, and recurring pain. Among the listed species, ten plants were found to be used according to traditional knowledge, although only four of them have been experimentally studied. When assessing the methodological quality of preclinical in vivo assays, most items presented a risk of bias. The SR results revealed the existence of different Plectranthus species used to treat inflammation and pain. The results of this systematic review indicate that Plectranthus species have the potential to be used in the treatment of diseases with an inflammatory component, as well as in the management of pain. However, given the risk of biases, the experimental analysis of these species through preclinical testing is crucial for their safe and effective use.

Essential oil and nanocarrier-based formulations approaches for vaginal candidiasis

An exclusive site for local drug delivery is the vagina, especially for vaginal infections. The fungus Candida albicans causes vaginal infection known as vulvovaginal candidiasis, a highly prevalent and recurrent gynaecological disease among women. Vaginal candidiasis affects over 75% of women at a certain point in their life and has a recurrence rate of 40-50%. Medicinal plants provide some very effective phytoconstituents which when delivered as nanosystems have enhanced therapeutic action and efficacy by alteration in their characteristics. Antifungal drugs are used to treat these conditions, alternative medicine is required for prophylaxis and improved prognosis. The current review focuses on the research carried out on various nanocarrier-based approaches and essential oil-based formulations for vaginal candidiasis.

Antihypertensive Activity of the Alkaloid Aspidocarpine in Normotensive Wistar Rats

The alkaloid Aspidocarpine was isolated from the bark of Aspidosperma desmanthum. Its structure was elucidated by the spectral data of 1H and 13C-NMR (1D and 2D) and high-resolution mass spectrometry (HRESIMS). The antihypertensive activity was investigated by intravenous infusion in Wistar rats. This alkaloid significantly reduced (p < 0.05) the systolic, median, and diastolic blood pressures of rodents, without causing motor incoordination and imbalance in the rotarod test. The results indicate that the alkaloid Aspidocarpine exerts its antihypertensive activity without causing sedation or the impairment of motor functions.

Antiplasmodial and cytotoxic effects of the methanol extract, canthinone alkaloids, squalene- and protolimonoid-type triterpenes from Homalolepis suffruticosa roots

ETHNOPHARMACOLOGICAL RELEVANCE

Different species of the Simaroubaceae family are used in traditional medicine to treat malaria. Among these is Homalolepis suffruticosa (syn. Simaba suffruticosa and Quassia suffruticosa), which is native to Central Brazil and popularly known as calunga. However, there is a lack of investigation concerning its antimalarial effects.

AIM OF THE STUDY

To investigate the antiplasmodial and cytotoxic effects of the isolated metabolites and methanol extract from H. suffruticosa roots as well as to conduct the dereplication of this extract aiming to characterize its metabolic profile by UPLC-DAD-ESI-MS/MS.

MATERIALS AND METHODS

Methanol extract of the H. suffruticosa roots and six isolated compounds were evaluated against chloroquine-resistant Plasmodium falciparum W2 strain by the PfLDH method and cytotoxicity in HepG2 cells by the MTT assay. Dereplication of the extract was performed by UPLC-DAD-ESI-MS/MS.

RESULTS

The six isolated compounds disclosed high to moderate antiplasmodial activity (IC₅₀ 0.0548 ± 0.0083 μg/mL to 26.65 ± 2.40 μg/mL) and cytotoxicity was in the range of CC₅₀ 0.62 ± 0.33 μg/mL to 56.43 ± 2.54 μg/mL, while 5-metoxycantin-6-one proved to be the most potent constituent of the six assayed ones. The methanol extract of the roots showed high in vitro antiplasmodial activity (IC₅₀ 1.88 ± 0.56 μg/mL), moderate cytotoxicity (CC₅₀ 41.93 ± 2.30 μg/mL), and good selectivity index (SI = 22.30). Finally, C₂₀ quassinoids and canthin-6-one alkaloids were putatively identified in the H. suffruticosa methanol extract by LC-MS.

CONCLUSIONS

Taken together, the isolated compounds, mainly the 5-metoxycantin-6-one and the methanol extract from H. suffruticosa roots, disclose good antiplasmodial activity, supporting the ethnopharmacological history of the Simaroubaceae species as traditional antimalarial drugs.

Saracura-Mirá, a Proposed Brazilian Amazonian Adaptogen from Ampelozizyphus amazonicus

The Amazon Forest is known all over the world for its diversity and exuberance, and for sheltering several indigenous groups and other traditional communities. There, as well as in several other countries, in traditional medical systems, weakness, fatigue and debility are seen as limiting health conditions where medicinal plants are often used in a non-specific way to improve body functions. This review brings together literature data on Ampelozizyphus amazonicus, commonly known in Brazil as "saracura-mirá" and/or "cerveja de índio", as an Amazonian adaptogen, including some contributions from the authors based on their ethnographic and laboratory experiences. Topics such as botany, chemistry, ethnopharmacological and pharmacological aspects that support the adaptogen character of this plant, as well as cultivation, market status and supply chain aspects are discussed, and the gaps to establish "saracura-mirá" as an ingredient for the pharmaceutical purposes identified. The revised data presented good scientific evidence supporting the use of this Amazonian plant as a new adaptogen. Literature data also reveal that a detailed survey on natural populations of this plant is needed, as well as agronomical studies that could furnish A. amazonicus bark as a raw material. Another important issue is the lack of developed quality control methods to assure its quality assessment.

Studies on Activities and Chemical Characterization of Medicinal Plants in Search for New Antimalarials: A Ten Year Review on Ethnopharmacology

Malaria is an endemic disease that affected 229 million people and caused 409 thousand deaths, in 2019. Disease control is based on early diagnosis and specific treatment with antimalarial drugs since no effective vaccines are commercially available to prevent the disease. Drug chemotherapy has a strong historical link to the use of traditional plant infusions and other natural products in various cultures. The research based on such knowledge has yielded two drugs in medicine: the alkaloid quinine from Cinchona species, native in the Amazon highland rain forest in South America, and artemisinin from Artemisia annua, a species from the millenary Chinese medicine. The artemisinin-based combination therapies (ACTs), proven to be highly effective against malaria parasites, and considered as “the last bullet to fight drug-resistant malaria parasites,” have limited use now due to the emergence of multidrug resistance. In addition, the limited number of therapeutic options makes urgent the development of new antimalarial drugs. This review focuses on the antimalarial activities of 90 plant species obtained from a search using Pubmed database with keywords “antimalarials,” “plants” and “natural products.” We selected only papers published in the last 10 years (2011–2020), with a further analysis of those which were tested experimentally in malaria infected mice. Most plant species studied were from the African continent, followed by Asia and South America; their antimalarial activities were evaluated against asexual blood parasites, and only one species was evaluated for transmission blocking activity. Only a few compounds isolated from these plants were active and had their mechanisms of action delineated, thereby limiting the contribution of these medicinal plants as sources of novel antimalarial pharmacophores, which are highly necessary for the development of effective drugs. Nevertheless, the search for bioactive compounds remains as a promising strategy for the development of new antimalarials and the validation of traditional treatments against malaria. One species native in South America, Ampelozyzyphus amazonicus, and is largely used against human malaria in Brazil has a prophylactic effect, interfering with the viability of sporozoites in in vitro and in vivo experiments.

Phytochemical profile and ethnopharmacological applications of Lecythidaceae: An overview

ETHNOPHARMACOLOGICAL RELEVANCE

The family Lecythidaceae has about 25 genera and 400 identified species, which are distributed especially in the pantropical region, mostly found in the tropics of Central and South America, Southeast Asia and Africa. The third most abundant family in Amazonian forests and the genus Eschweilera, with the large number of species in Lecythidaceae.

AIM OF THE REVIEW

The present review compiles information since the 1934s about of ethnopharmacology, and chemical constituents of species of Lecythidaceae, as well as a summary of the bioactivities shown by the extracts, fractions, and secondary metabolites.

MATERIALS AND METHODS

All relevant information on ethnopharmacology, and chemical constituents of species of Lecythidaceae were gathered from electronic databases including Web of Science, Science Direct, Elsevier, ResearchGate, and Google Scholar. Information was also obtained from local books, PhD. and MSc. Dissertations.

RESULTS

The phytochemical diversity of the family was demonstrated with 180 different metabolites that have been reported from 25 species, most of them being triterpenes or flavonoids. The pharmacological studies carried out with the extracts, fractions and compounds showed promising antibacterial, antifungal, anti-inflammatory, antinociceptive, cytotoxic and antioxidant activities.

CONCLUSION

The present review provides an insight into ethnopharmacology, phytochemistry and pharmacology of species of Lecythidaceae. Based on the pharmacological studies it has been found that different plant species of Lecythidaceae possess a wide range of bioactivities such as anti-arthritic, anti-inflammatory, antileishmanial, antibacterial and antifungal. These activities are due to the presence of bioactive compounds including triterpenoids and their glycosides derivatives, flavonoids, steroids, sesquiterpenoids, alkaloids, and other compounds. However, there are many plants, which have not been assessed pharmacologically and hence warrant further studies.

Forest Fevers: traditional treatment of malaria in the southern lowlands of Laos

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria is still a highly challenging public health issue in southern Lao PDR, with increasing cases of artemisinin resistance and Plasmodium vivax infections which are more complicated to treat. Traditional medicine has a long history of use in Laos, and is primarily practised by traditional village healers, who possess unique bodies of transmitted knowledge focused on herbal prescriptions, including those for the treatment of malaria. Villagers also use plants for healthcare in the home. The aim of the study is to document local fever concepts and use of herbal remedies, and examine whether they may have potential as complementary treatments against malaria.

MATERIALS AND METHODS

The study took place in Champasak province in the far south of Laos, in primarily lowland areas. First, 35 traditional healers across the 10 districts of the province were interviewed to elicit details about knowledge and treatment of fevers. Second, a household survey was conducted in a village in a malaria-endemic area; 97 households were interviewed on fever incidence, differentiation, treatment-seeking behaviour and knowledge of plant-based remedies for fevers. Plants indicated by both healers and villagers were collected and voucher specimens deposited in the herbarium of the National University of Laos for identification.

RESULTS

Malaria is a well-known pathology among the healers and villagers of lowland Champasak province; biomedical treatments are preferentially used, but traditional medicine is a popular complementary method, especially in chronic cases with additional symptoms. 30 different fever types were recorded, which were usually named symptomatically, and grouped into 12 categories. Some were described as forms of malaria, which was conceived as a dynamic, changing pathology affecting many body systems. Healers formulate treatments based on symptoms and the person's constitution, and with the intention of creating specific pharmacological actions associated with temperature or flavours. 11 of the healers gave prescriptions for malaria (27 in total), including 47 identified plant species. The most-used plants (4 or more use-reports) were also the most cited in the literature for use against malaria, demonstrating a correspondence between Lao healers and other traditional medical systems. Furthermore, some of these species show promising results for future research, especially Amorphophallus paeniifolius (Dennst.) Nicolson and Alocasia macrorrhizos (L.) G. Don.

CONCLUSION

Traditional healers are important actors in the treatment of malaria in southern Laos, and herbal remedies should be evaluated further by the use of reverse treatment outcome trials, especially those which may be of use as complementary remedies in treating P. vivax. Initiatives on knowledge transmission, medicinal plant conservation and healthcare integration are also urgently needed.

Antimalarial herbal remedies of Bukavu and Uvira areas in DR Congo: An ethnobotanical survey

ETHNOPHARMACOLOGICAL RELEVANCE

The main objective of the present study was to collect and gather information on herbal remedies traditionally used for the treatment of malaria in Bukavu and Uvira, two towns of the South Kivu province in DRC.

MATERIAL AND METHODS

Direct interview with field enquiries allowed collecting ethnobotanical data; for each plant, a specimen was harvested in the presence of the interviewed traditional healers (THs). The recorded information included vernacular names, morphological parts of plants, methods of preparation and administration of remedies, dosage and treatment duration. Plants were identified with the help of botanists in the herbaria of INERA/KIPOPO (DRC) and the Botanic Garden of Meise (Belgium), where voucher specimens have been deposited. The results were analysed and discussed in the context of previous published data.

RESULTS

Interviewees cited 45 plant species belonging to 41 genera and 21 families used for the treatment of malaria. These plants are used in the preparation of 52 recipes, including 25 multi-herbal recipes and 27 mono-herbal recipes. Apart of Artemisia annua L. (Asteraceae; % Citation frequency = 34%) and Carica papaya L. (Caricaceae; % Citation frequency = 34%), the study has highlighted that the most represented families are Asteraceae with 12 species (26%), followed by Fabaceae with 7 species (16%) and Rubiaceae with 4 species (9%). For a majority of plants, herbal medicines are prepared from the leaves in the form of decoction and administered by oral route.

CONCLUSION

Literature data indicate that part of cited species are already known (38%) and/or studied (30%) for antimalarial properties, which gives credit to the experience of Bukavu and Uvira interviewees and some level of confidence on collected information. The highly cited plants should be investigated in details for the isolation and identification of active ingredients, a contribution to the discovery of new possibly effective antimalarials.

The genus Jatropha (Euphorbiaceae): A review on secondary chemical metabolites and biological aspects

The genus Jatropha belongs to the Euphorbiaceae family and has about 175 species. Originally from tropical America, the Jatropha genus can be found all over the tropics and subtropics of Asia and Africa. Jatropha species are recognized to be important sources of secondary metabolites with a broad spectrum of biological functions. Extracts and isolated compounds from species of this genus have been known to have properties of cytotoxicity, antimicrobial, antifungal, anti-inflammatory, antioxidant, insecticidal, larvicidal, inhibition AChE, and toxicity activities. Investigations on the chemical aspects of the genus Jatropha have led to the identification of cyclic peptides, lignans, flavonoids, coumarins, alkaloids, eudesmenoic acids, and mainly terpenes. In this review, we provide a comprehensive picture of the phytochemical and biological characteristics of Jatropha species. The information gathered and approached in this paper might support the planning and discussion of future studies on the topic.

Chemical Genomic Profiling Unveils the in Vitro and in Vivo Antiplasmodial Mechanism of Açaí (Euterpe oleracea Mart.) Polyphenols

Malaria remains a major detrimental parasitic disease in the developing world, with more than 200 million cases annually. Widespread drug-resistant parasite strains push for the development of novel antimalarial drugs. Plant-derived natural products are key sources of antimalarial molecules. Euterpe oleracea Martius ("açaí") originates from Brazil and has anti-inflammatory and antineoplasic properties. Here, we evaluated the antimalarial efficacy of three phenolic fractions of açaí; total phenolics (1), nonanthocyanin phenolics (2), and total anthocyanins (3). In vitro, fraction 2 moderately inhibited parasite growth in chloroquine-sensitive (HB3) and multiresistant (Dd2) Plasmodium falciparum strains, while none of the fractions was toxic to noncancer cells. Despite the limited activity in vitro, the oral treatment with 20 mg/kg of fraction 1 reduced parasitemia by 89.4% in Plasmodium chabaudi-infected mice and prolonged survival. Contrasting in vitro and in vivo activities of 1 suggest key antiplasmodial roles for polyphenol metabolites rather than the fraction itself. Finally, we performed haploinsufficiency chemical genomic profiling (HIP) utilizing heterozygous Saccharomyces cerevisiae deletion mutants to identify molecular mechanisms of açaí fractions. HIP results indicate proteostasis as the main cellular pathway affected by fraction 2. These results open avenues to develop açaí polyphenols as potential new antimalarial candidates.

Aspidosperma species: A review of their chemistry and biological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Species of Aspidosperma are known popularly as "peroba, guatambu, carapanaúba, pau-pereiro" and "quina". The genus can be found in the Americas, mainly between Mexico and Argentina. Many species of Aspidosperma are used by the population in treating cardiovascular diseases, malaria, fever, diabetes and rheumatism. The phytochemical aspects of the species of the genus Aspidosperma have been studied extensively. The monoterpene indole alkaloids are the main secondary metabolites in Aspidosperma species, and about 250 of them have been isolated showing a considerable structural diversity. Several of them have showed some important pharmacological activities. Aspidosperma subincanum Mart. and Aspidosperma tomentosum Mart. (Apocynaceae) are Brazilian species widely used by the population to treat diabetes mellitus, hypercholesterolemia. The pharmacological activities of both species have been investigated and the biological properties described can be related to their isolated indole alkaloids. However, more pharmacological studies are needed in order to justify the use of these species in folk medicine. In this review, we present reports mainly focused on chemical and biological studies and their relationship with the ethnopharmacological use of both Aspidosperma species.

AIM OF THE STUDY

The aim of this review is to present their ethnopharmacological use as correlated to their biological activities as described for the extracts and isolated compounds from Aspidosperma subincanum Mart. and Aspidosperma tomentosum Mart. In addition, some aspects related to the biosynthetic pathways are discussed, also NMR assignments and some synthesis information about indole alkaloids from both Aspidosperma species are included.

MATERIAL AND METHODS

The bibliographic search was made in theses and dissertations using some databases such as NDLTD (Networked Digital Library of Theses and Dissertations), OATD (Open Access Theses and Dissertations) and Google Scholar. More data were gathered from books, Brazilian journals and articles available on electronic databases such as, Google Scholar, PubChem, Scifinder, Web of Science, SciELO, PubMed and Science Direct. Additionally, the Google Patents and Espacenet Patent Search (EPO) were also consulted. The keywords Aspidosperma, A. subincanum, A. tomentosum, indole alkaloids were used in the research. The languages were restricted to Portuguese, English and Spanish and references were selected according to their relevance.

RESULTS

A. subincanum Mart. and A. tomentosum Mart. (Apocynaceae) are Brazilian species widely used by the population to treat a few diseases. Extracts and isolated compounds of both species have shown antitumor and antimalarial activities. The antitumor activity of isolated compounds has been extensively studied. However, the antiplasmodial activity needs to be investigated further as well as the anti-inflammatory, anti-hyperlipidemic and anorexigenic activities. From A. subincanum twenty-one indole alkaloids were isolated and some of them have been extensively studied. From the leaves and bark of A. tomentosum four alkaloids and one flavonoid were isolated. Furthermore, CG-MS analysis of seeds, branches, leaves and arils identified nine indole alkaloids. Stemmadenine has been proposed as a precursor of indole alkaloids obtained from some species of Aspidosperma. Many of the biosynthetic steps have been characterized at the enzymatic level and appropriate genes have been identified, however, other steps have yet to be investigated and they are still controversial. Some isolated alkaloids from A. subincanum and A. tomentosum were identified only by mass spectrometry. In many cases, their NMR data was either not available or was incomplete. The described meta-analysis of the available NMR data revealed that the chemical shifts belonging to the indole ring might be used to characterize this class of alkaloids within complex matrices such as plant extracts. The biological activities and the structural complexity of these compounds have stimulated the interest of many groups into their synthesis. In this review, some information about the synthesis of indole alkaloids and their derivatives was presented.

CONCLUSIONS

A. subincanum and A. tomentosum are used by the population of Brazil to treat many diseases. A few biological activities described for the extracts and isolated compounds of both species are in agreement with the ethnopharmacological use for others species of Aspidosperma, such as, antimalarial, the treatment of diabetes and other illnesses. These species are sources of leading compounds which can be used for developing new drugs. In addition, other biological activities reported and suggested by ethnopharmacological data have yet to be investigated and could be an interesting area in the search for new bioactive compounds.

In vitro antiplasmodial activity and identification, using tandem LC-MS, of alkaloids from Aspidosperma excelsum, a plant used to treat malaria in Amazonia

ETHNOPHARMACOLOGICAL RELEVANCE

Aspidosperma excelsum Benth. (Apocynaceae), a native tree in the Brazilian Amazonia, is traditionally used to treat various diseases, including malaria.

AIM OF STUDY

To investigate the chemical constitution, antiplasmodial activity and cytotoxicity of samples obtained from A. excelsum trunk bark by different procedures aiming to evaluate their potential as an antimalarial phytomedicine.

MATERIALS AND METHODS

A hydroethanolic extract and alkaloid extracts were prepared and assayed for antiplasmodial activity and cytotoxicity against chloroquine-resistant Plasmodium falciparum (W2 strain) and HepG2 cells, respectively. Taking into account the known occurrence and antimalarial activity of Aspidosperma monoterpene indole alkaloids (MIA), acid-base extractions were carried out and the fractions were assayed for antiplasmodial activity and cytotoxicity. All the samples were analysed by hyphenated chromatographic techniques, such as UPLC-DAD-ESI-MS/MS and HRMS (HPLC-MS MicroTOF), comparing their chemical composition to the literature data.

RESULTS

The hydroethanolic extract disclosed a moderate in vitro activity against chloroquine-resistant Plasmodium falciparum (W2 strain) with IC₅₀ 23.68 ± 3.08 µg/mL), low cytotoxicity to HepG2 cells (> 250 µg/mL) and good SI (> 10.56). A total of 20 known monoterpene indole alkaloids were identified, seven of which are here firstly described for A. excelsum. Known highly active alkaloids, namely demethylaspidospermine, aspidocarpine, and ochrolifuanine are present in active alkaloid fractions and might contribute to their observed antiplasmodial effect. An alkaloid fraction (Ae-Alk2), obtained directly from trunk bark by extraction with dil. aqueous HCl, pointed out for its activity (IC₅₀ 8.75±2.26 µg/mL, CC₅₀ 185.14±1.97 µg/mL, SI 21.16) and should be highlighted as the most promising out of the assayed samples.

CONCLUSION

The present results represent a preliminary support to the alleged antimalarial use of A. excelsum trunk bark and allowed to highlight alkaloid fractions as promising phytomedicines.

Aspidosperma pyrifolium, a medicinal plant from the Brazilian caatinga, displays a high antiplasmodial activity and low cytotoxicity

Background

Several species of Aspidosperma plants are referred to as remedies for the treatment of malaria, especially Aspidosperma nitidum. Aspidosperma pyrifolium, also a medicinal plant, is used as a natural anti-inflammatory. Its fractionated extracts were assayed in vitro for activity against malaria parasites and for cytotoxicity.

Methods

Aspidosperma pyrifolium activity was evaluated against Plasmodium falciparum using extracts in vitro. Toxicity towards human hepatoma cells, monkey kidney cells or human monocytes freshly isolated from peripheral blood was also assessed. Anti-malarial activity of selected extracts and fractions that presented in vitro activity were tested in mice with a Plasmodium berghei blood-induced infection.

Results

The crude stem bark extract and the alkaloid-rich and ethyl acetate fractions from stem extract showed in vitro activity. None of the crude extracts or fractions was cytotoxic to normal monkey kidney and to a human hepatoma cell lines, or human peripheral blood mononuclear cells; the MDL₅₀ values of all the crude bark extracts and fractions were similar or better when tested on normal cells, with the exception of organic and alkaloidic-rich fractions from stem extract. Two extracts and two fractions tested in vivo caused a significant reduction of P. berghei parasitaemia in experimentally infected mice.

Conclusion

Considering the high therapeutic index of the alkaloidic-rich fraction from stem extract of A. pyrifolium, it makes the species a candidate for further investigation aiming to produce a new anti-malarial, especially considering that the active extract has no toxicity, i.e., no mutagenic effects in the genototoxicity assays, and that it has an in vivo anti-malarial effect. In its UPLC-HRMS analysis this fraction was shown to have two major components compatible with the bisindole alkaloid Leucoridine B, and a novel compound, which is likely to be responsible for the activity against malaria parasites demonstrated in in vitro tests.

Herbal bathing: an analysis of variation in plant use among Saramaccan and Aucan Maroons in Suriname

BACKGROUND

Herbal baths play an important role in the traditional health care of Maroons living in the interior of Suriname. However, little is known on the differences in plant ingredients used among and within the Maroon groups. We compared plant use in herbal baths documented for Saramaccan and Aucan Maroons, to see whether similarity in species was related to bath type, ethnic group, or geographical location. We hypothesized that because of their dissimilar cultural background, they used different species for the same type of bath. We assumed, however, that plants used in genital baths were more similar, as certain plant ingredients (e.g., essential oils), are preferred in these baths.

METHODS

We compiled a database from published and unpublished sources on herbal bath ingredients and constructed a presence/absence matrix per bath type and study site. To assess similarity in plant use among and within Saramaccan and Aucan communities, we performed three Detrended Correspondence Analyses on species level and the Jaccard Similarity Index to quantify similarity in bath ingredients.

RESULTS

We recorded 349 plants used in six commonly used bath types: baby strength, adult strength, skin diseases, respiratory ailments, genital steam baths, and spiritual issues. Our results showed a large variation in plant ingredients among the Saramaccan and Aucans and little similarity between Saramaccans and Aucans, even for the same type of baths. Plant ingredients for baby baths and genital baths shared more species than the others. Even within the Saramaccan community, plant ingredients were stronger associated with location than with bath type.

CONCLUSIONS

Plant use in bathing was strongly influenced by study site and then by ethnicity, but less by bath type. As Maroons escaped from different plantations and developed their ethnomedicinal practices in isolation, there has been little exchange in ethnobotanical knowledge after the seventeenth century between ethnic groups. Care should be taken in extrapolating plant use data collected from one location to a whole ethnic community. Maroon plant use deserves more scientific attention, especially now as there are indications that traditional knowledge is disappearing.

As vivid as a weed… Medicinal and cosmetic plant uses amongst the urban youth in French Guiana

ETHNOPHARMACOLOGICAL RELEVANCE

French Guiana is a French overseas territory with a rich history of migration that has led to a highly intercultural society. Today, its population is one of the youngest in the French territory and is rapidly increasing. Despite a context of cultural revival seeking "tradition", a distanced baseline of local practices is still lacking. This work addresses some aspects of the cultural hybridizations in progress in urban areas.

METHODS

Semi directed interviews were conducted with willing participants aged between 18 and 40. Interviews took place in French Guiana's two main urban centres: Cayenne and Saint Laurent du Maroni. People were interviewed about the last medicinal plant they used in the preceding year. Due to the high use of plant baths in French Guiana, a focus was made on baths.

RESULTS AND DISCUSSION

Eighty-three people answered: 43 women and 40 men (mean age of 28.7 years old). In total, 226 remedies were counted in our study, 155 single plant remedies and 71 compound remedies leading to 316 use reports of plants from 16 cultural groups. A surprising number of 108 botanical species were recorded. Eighty-one recipes for baths were also collected. Despite this high citation rate, a rather low proportion of people declare a systematic and regular recourse upon local pharmacopoeia (46%; 38/83). Although many interviewees used plants, far from the majority used them on a regular basis. In practice, 50% of the species (54/108 spp.; 99/316 URs) are non-native but domesticated exotic species, imported from Asia, Europe, Africa or remote parts of America, either during colonization, the slave trade era, or more recently with the latest migrations.

CONCLUSION

Although phytotherapy use is often thought to be related to countryside dwellers and older people, medicinal plants seem to play an important role in the lives of urban French Guianese youth. Research shows a large diversity of medicinal species used linked with the great cultural diversity of the Guianese cities. One characteristic of this population is the hybridization process leading to a perpetual renewal of practices, both in terms of species and practice.

Aspidosperma (Apocynaceae) plant cytotoxicity and activity towards malaria parasites. Part II: experimental studies withAspidosperma ramiflorum in vivo and in vitro

Several species of Aspidosperma plants are used to treat diseases in the tropics, including Aspidosperma ramiflorum, which acts against leishmaniasis, an activity that is experimentally confirmed. The species, known as guatambu-yellow, yellow peroba, coffee-peroba and matiambu, grows in the Atlantic Forest of Brazil in the South to the Southeast regions. Through a guided biofractionation of A. ramiflorum extracts, the plant activity against Plasmodium falciparum was evaluated in vitro for toxicity towards human hepatoma G2 cells, normal monkey kidney cells and nonimmortalised human monocytes isolated from peripheral blood. Six of the seven extracts tested were active at low doses (half-maximal drug inhibitory concentration < 3.8 µg/mL); the aqueous extract was inactive. Overall, the plant extracts and the purified compounds displayed low toxicity in vitro. A nonsoluble extract fraction and one purified alkaloid isositsirikine (compound 5) displayed high selectivity indexes (SI) (= 56 and 113, respectively), whereas compounds 2 and 3 were toxic (SI < 10). The structure, activity and low toxicity of isositsirikine in vitro are described here for the first time in A. ramiflorum, but only the neutral and precipitate plant fractions were tested for activity, which caused up to 53% parasitaemia inhibition of Plasmodium berghei in mice with blood-induced malaria. This plant species is likely to be useful in the further development of an antimalarial drug, but its pharmacological evaluation is still required.

Molecular Farming in Artemisia annua, a Promising Approach to Improve Anti-malarial Drug Production

Malaria is a parasite infection affecting millions of people worldwide. Even though progress has been made in prevention and treatment of the disease; an estimated 214 million cases of malaria occurred in 2015, resulting in 438,000 estimated deaths; most of them occurring in Africa among children under the age of five. This article aims to review the epidemiology, future risk factors and current treatments of malaria, with particular focus on the promising potential of molecular farming that uses metabolic engineering in plants as an effective anti-malarial solution. Malaria represents an example of how a health problem may, on one hand, influence the proper development of a country, due to its burden of the disease. On the other hand, it constitutes an opportunity for lucrative business of diverse stakeholders. In contrast, plant biofarming is proposed here as a sustainable, promising, alternative for the production, not only of natural herbal repellents for malaria prevention but also for the production of sustainable anti-malarial drugs, like artemisinin (AN), used for primary parasite infection treatments. AN, a sesquiterpene lactone, is a natural anti-malarial compound that can be found in Artemisia annua. However, the low concentration of AN in the plant makes this molecule relatively expensive and difficult to produce in order to meet the current worldwide demand of Artemisinin Combination Therapies (ACTs), especially for economically disadvantaged people in developing countries. The biosynthetic pathway of AN, a process that takes place only in glandular secretory trichomes of A. annua, is relatively well elucidated. Significant efforts have been made using plant genetic engineering to increase production of this compound. These include diverse genetic manipulation approaches, such as studies on diverse transcription factors which have been shown to regulate the AN genetic pathway and other biological processes. Results look promising; however, further efforts should be addressed toward optimization of the most cost-effective biofarming approaches for synthesis and production of medicines against the malaria parasite.