Alkaloid from Geissospermum sericeum Benth. & Hook.f. ex Miers (Apocynaceae) Induce Apoptosis by Caspase Pathway in Human Gastric Cancer Cells.

Gastric cancer is among the major causes of death from neoplasia leading causes of death worldwide, with high incidence rates and problems related to its treatment. Here, we outline how Geissospermum sericeum exerts antitumor activity on the ACP02 cell line (human gastric adenocarcinoma) and the mechanism of cell death. The ethanol extract and fractions, neutral fraction and alkaloid fraction, were characterized by thin-layer chromatography and HPLC-DAD, yielding an alkaloid (geissoschizoline N4-methylchlorine) identified by NMR. The cytotoxicity activity of the samples (ethanol extract, neutral fraction, alkaloid fraction, and geissoschizoline N4-methylchlorine) in HepG2 and VERO cells was determined by MTT. The ACP02 cell line was used to assess the anticancer potential. Cell death was quantified with the fluorescent dyes Hoechst 33342, propidium iodide, and fluorescein diacetate. The geissoschizoline N4-methylchlorine was evaluated in silico against caspase 3 and 8. In the antitumor evaluation, there was observed a more significant inhibitory effect of the alkaloid fraction (IC50 18.29 µg/mL) and the geissoschizoline N4-methylchlorine (IC50 12.06 µg/mL). However, geissoschizoline N4-methylchlorine showed lower cytotoxicity in the VERO (CC50 476.0 µg/mL) and HepG2 (CC50 503.5 µg/mL) cell lines, with high selectivity against ACP02 cells (SI 39.47 and 41.75, respectively). The alkaloid fraction showed more significant apoptosis and necrosis in 24 h and 48 h, with increased necrosis in higher concentrations and increased exposure time. For the alkaloid, apoptosis and necrosis were concentration- and time-dependent, with a lower necrosis rate. Molecular modeling studies demonstrated that geissoschizoline N4-methylchlorine could occupy the active site of caspases 3 and 8 energetically favorably. The results showed that fractionation contributed to the activity with pronounced selectivity for ACP02 cells, and geissoschizoline N4-methylchlor is a promising candidate for caspase inhibitors of apoptosis in gastric cancer. Thus, this study provides a scientific basis for the biological functions of Geissospermum sericeum, as well as demonstrates the potential of the geissoschizoline N4-methylchlorine in the treatment of gastric cancer.

Bioprospection for new larvicides against Aedes aegypti based on ethnoknowledge from the Amazonian São Sebastião de Marinaú riverside community.

ETHNOPHARMACOLOGICAL RELEVANCE: Vector-borne diseases represent a huge global burden impacting health systems. Aedes aegypti is the main vector of arboviral diseases including dengue, Zika, chikungunya and urban yellow fever in both tropical and subtropical areas. Ethnopharmacological investigations provide potential avenues for developing new vector control strategies. AIM OF THE STUDY: The objective of this study is to document the São Sebastião de Marinaú riverside community's ethnoknowledge of local plants used to control mosquitoes and perform bioguided fractionation to isolate the compounds active against the arboviral disease vector Ae. aegypti. MATERIALS AND METHODS: Semi-structured interviews were conducted with residents of the Marinaú community located in the Caxiuanã National Forest, in the Amazon biome, Pará, Brazil. The plants used to control mosquitoes were subjected to phytochemical studies guided by Ae. aegypti assays. Extracts were obtained from seven species using distinct organic solvents. Active extracts and fractions were separated by chromatographic techniques. Isolated compounds were characterized by NMR, LC/MS and GC/MS. Sample activity against Ae. aegypti larvae and pupae was evaluated after 24, 48 and 72 h exposure. The extracts were also investigated against adult female mosquitoes. The LC50 values were determined by diluting each sample to obtain different concentrations in the respective activity range. RESULTS: The Marinaú community uses more than ten plants as a repellent, most of which are trees native to the region. The primary applications of these plants to protect against insect bites were: burning plants (fumigation), application of body oils and bathing in macerated plants. Carapa guianensis is the predominant species used as a repellent. Extracts from Diospyros guianensis fruits, Carapa guianensis seed shells and Aspidosperma nitidum wood demonstrated Ae. aegypti larvicidal activity. The C. guianensis seed shell extract demonstrated a residual larvicidal effect. Plumbagin, stigmasterol, ß-sitosterol, betulinic, ursolic and oleanolic acids, and betulin were identified in the D. guianensis extract. The plumbagin, ursolic and oleanolic acids displayed larvicidal activity. Oleanolic, ursolic and betulinic acids, and betulin were considered pupicidal. Aricine, the major alkaloid isolated from A. nitidum wood, also presented larvicidal activity. CONCLUSIONS: Ten plant species traditionally used by the Marinaú community to afford protection against mosquitoes were reported. C. guianensis, D. guianensis and A. nitidum extracts were considered larvicidal against Ae. aegypti. Four triterpenes stood out as very active compounds against pupae. Aricine, an indole alkaloid, displayed larvicidal activity. Therefore, traditional knowledge of Amazonian plants combined with bioguided fractionation constitutes a strategy for the development of eco-friendly insecticides to control Ae. aegypti, an arbovirus vector.

Evaluation of acute and subacute toxicity of ethanolic extract and fraction of alkaloids from bark of Aspidosperma nitidum in mice.

This study investigated the acute and subacute toxicity of the ethanolic extract (EE) and alkaloid fraction (FA) from A. nitidum. The EE was obtained from trunk bark with ethanol, FA was obtained from the fractionation of EE. To test the acute toxicity, mice were divided into four groups, and the negative controls received water or aqueous solution of dimethyl sulfoxide, whereas the others received EE or FA (2000 mg/kg, orally, single dose). The same controls were used in the subacute trial. However, the animals were treated for 28 days, and the dose used was 1000 mg/kg per day of EE and FA. Daily clinical evaluations of the animals were performed. At the end of the experiment, hematological, biochemical, and histopathological assessments (liver, lung, heart, and kidney) were performed. In the acute and subacute toxicity studies, mice treated with EE and FA did not show any clinical changes, there were no changes in weight gain, hematological and biochemical parameters compared to the control groups (p > 0.05). In the histopathological examination, there was no abnormality in the organs of the treated animals. Therefore, EE and FA did not produce toxic effects in mice after acute and subacute treatment.

Useful plants and their relation to archaeological sites in the Serra de Carajás, Brazil.

Multidisciplinary studies including archeology and ethnobotany that seek to understand human interventions on the landscape have obtained important results concerning Amazon biodiversity. This study aims to identify the useful plants in different phytophysiognomies related to archeological sites in the Serra de Carajás, in the state of Pará, as well as expand knowledge of the local flora. Information was collected in 76 parcels located in the influence areas of 15 archaeological sites: 45 in forest vegetation, 30 in canga vegetation and 1 in palm swamps. The species were categorized as either medicinal, food, game attractants, firewood, toxic, ritualistic and material. An assessment of the plants use potential by family was done using regression analysis for the taxa inventoried. All the phytophysiognomies studied in the vicinity of archaeological sites were expressive regarding useful species. The most representative categories were medicinal, material, game attractant, firewood and food. The floristic features related to the use of plant species by family were also expressive for Fabaceae, Myrtaceae and Chrysobalanaceae. The phytophysiognomies identified near archaeological sites feature several plant resources in different use categories, highlighting the value of local ecosystems and their potential for human use.

Flavopereirine-An Alkaloid Derived from Geissospermum vellosii-Presents Leishmanicidal Activity In Vitro.

Chemotherapy is limited in the treatment of leishmaniasis due to the toxic effects of drugs, low efficacy of alternative treatments, and resistance of the parasite. This work assesses the in vitro activity of flavopereirine on promastigote cultures of Leishmania amazonensis. In addition, an in silico evaluation of the physicochemical characteristics of this alkaloid is performed. The extract and fractions were characterized by thin-layer chromatography and HPLC-DAD, yielding an alkaloid identified by NMR. The antileishmanial activity and cytotoxicity were assayed by cell viability test (MTT). The theoretical molecular properties were calculated on the Molinspiration website. The fractionation made it possible to isolate a beta-carboline alkaloid (flavopereirine) in the alkaloid fraction. Moreover, it led to obtaining a fraction with greater antileishmanial activity, since flavopereirine is very active. Regarding the exposure time, a greater inhibitory effect of flavopereirine was observed at 24 h and 72 h (IC50 of 0.23 and 0.15 µg/mL, respectively). The extract, fractions, and flavopereirine presented low toxicity, with high selectivity for the alkaloid. Furthermore, flavopereirine showed no violation of Lipinski's rule of five, showing even better results than the known inhibitor of oligopeptidase B, antipain, with three violations. Flavopereirine also interacted with residue Tyr-499 of oligopeptidase B during the molecular dynamics simulations, giving a few insights of a possible favorable mechanism of interaction and a possible inhibitory pathway. Flavopereirine proved to be a promising molecule for its antileishmanial activity.

Antileishmanial Activity of Handroanthus serratifolius (Vahl) S. Grose (Bignoniaceae).

This study aimed to evaluate the leishmanicidal activity of ethanol extract, fractions, and isolated substance from Handroanthus serratifolius against Leishmania amazonensis. Furthermore, this activity was related to cytotoxicity, and the selectivity index was determined. The ethanol extract was obtained by maceration of the stem powder, and the extract was subjected to fractionation on chromatographic column. The lapachol was obtained by acid base extraction followed by purification in chromatographic column. The antipromastigote activity and cytotoxicity tests were carried out by the cell viability method (MTT). Modified THP-1 cells were infected with L. amazonensis promastigotes and treated for 24 h with different concentrations of the extract, fractions, and lapachol. The ethanol extract, dichloromethane, and ethyl acetate fractions were not active against promastigotes (IC50 > 200 µg/mL) or cytotoxic (CC50 > 500 µg/mL), and the selectivity index (SI) was greater than 2.5. The ethyl acetate fraction was active only in promastigotes; it is not cytotoxic (CC50 > 500 µg/mL, SI > 5). The lapachol was selectively active only against amastigote (IS > 2.5, CC50 > 500 µg/mL). In summary, lapachol and ethyl acetate fraction are promising against amastigote and promastigote forms, respectively.

Morphology, ontogeny and structure of the stipular nectaries in Caamembeca spectabilis (Polygalaceae) / Morfologia, ontogenia e estrutura dos nectários estipulares em Caamembeca spectabilis (Polygalaceae)

Nodal glands are found in one third of the Polygalaceae genera and have valuable taxonomic, ecological and evolutionary significance. In Brazil, they occur in five of the eleven genera already registered. However, there is still a controversy regarding the origin of these structures. The objective of this study was to characterize the morphology and the origin of nodal glands inCaamembeca spectabilis, in order to increase the structural and functional knowledge of these glands in the genera. Samples of nodal regions were collected, fixed and processed according to the methods of light microscopy and electron scanning. Ants were observed and identified along the stem axis. The glucose in exudate allows us to classify these glands as extrafloral nectaries. They are located in pairs on the nodal region. However, its origin is in the leaf trace. In the longitudinal section, the nectaries were present in the apex of cells with anticlinal walls impregnated with suberin, which represents the first record for the family. In this region there is also the formation of a hole by lysis. The secretory tissue is surrounded by phloem. Xylem vessels were observed only on the basis of the nectary, where there are also idioblasts with crystals in druse type. We have studied the ontogeny of the glands nodal in Caamembeca spectabilis and unveiled that these glands are linked to the leaves as stipular nectaries. In addition, the new findings presented here may add support for the understanding of morphology and anatomy of nodal glands in Caamembeca.

Glândulas nodais são encontradas em um terço dos gêneros de Polygalaceae e possuem grande importância taxonômica, ecológica e evolutiva. No Brasil, ocorrem em cinco, dos onze gêneros já registrados. Contudo, ainda há controvérsias quanto à origem dessas estruturas. O objetivo deste trabalho foi caracterizar a morfologia e a origem das glândulas nodais em Caamembeca spectabilis, visando ampliar o conhecimento estrutural e funcional dessas glândulas no gênero. Amostras das regiões nodais foram coletadas, fixadas e processadas segundo os métodos em microscopia de luz e eletrônica de varredura. Formigas foram observadas e identificadas ao longo do eixo caulinar. A glicose no exsudato permite tratar as glândulas como nectários extraflorais. Esses estão localizados aos pares na região nodal. Porém, sua origem ocorre no traço foliar. Os nectários, em secção longitudinal, apresentam as células do ápice com paredes anticlinais impregnadas com suberina, sendo este o primeiro registro para a família. Nessa região também ocorre a formação de um orifício por lise. O tecido secretor do nectário é circundado pelo floema. Vasos de xilema foram observados apenas na base do nectário, onde também ocorrem idioblastos com cristais do tipo drusas. Dessa forma, este estudo confirma a trajetória ontogenética das glândulas nodais em C. spectabilis, as quais, de fato, estão ligadas às folhas, como nectários estipulares. Além de apresentar dados inéditos que auxiliam a compreensão morfológica e anatômica das mesmas em Caamembeca.

Estruturas secretoras da lâmina foliar de amapá amargo (Parahancornia fasciculata, Apocynaceae): histoquímica e doseamento de flavonoides / Secretory structures from the leaf blade of bitter amapá (Parahancornia fasciculata, Apocynaceae): histochemistry and assay of flavonoids

Bitter amapa (Parahancornia fasciculata (Poir.) Benoist) produces a latex, which is presumed to have medicinal properties, as it is used in the treatment of malaria, lung problems, gastritis, and as healing agent. This study aimed to analyze structural and histochemically the sites of production and/or accumulation of biologically active compounds, as well as to determine the kind of flavonoids present in the leaf blade of bitter amapa. For structural and histochemical analysis we used standard protocols in plant anatomy. Whereas to assay flavonoids we used absorption spectrometry in the ultraviolet-visible region. The secretory system of bitter amapa leaves is constituted of both secretory idioblasts and branched laticifers. Histochemical tests revealed different types of chemical substances in the cell protoplast of idioblasts and laticifers. Pharmacological properties of bitter amapa latex can be attributed to two chemical compounds (flavonoids and alkaloids) found in this study, both of them are present in idioblasts and laticifers.

Amapá amargo (Parahancornia fasciculata (Poir.) Benoist) produz um látex, que se presume ter propriedades medicinais, pois é usado no tratamento da malária, problemas pulmonares, gastrite, e como um agente de cura. Este estudo teve como objetivo analisar estrutural e histoquimicamente os locais de produção e/ou acumúlo de compostos biologicamente ativos, bem como realizar o doseamento de flavonóides presentes no limbo do amapá amargo. Para a análise estrutural e histoquímica foram utilizados protocolos padrão em anatomia vegetal. Considerando que, para o doseamento de flavonóides utilizou-se a espectrometria de absorção na região ultravioleta-visível. O sistema secretor das folhas de amapá amargo é constituído de idioblastos secretores e laticíferos ramificados. Os testes histoquímicos revelaram diferentes tipos de substâncias químicas nos protoplastos celulares de idioblastos e laticíferos. Propriedades farmacológicas do látex de amapa amargo podem ser atribuídas à dois compostos químicos (flavonoides e alcaloides) encontrados neste estudo, ambos estão presentes em idioblastos e laticíferos.

Estudo etnobotânico de Mauritia flexuosa L. f. (Arecaceae) em comunidades ribeirinhas do Município de Abaetetuba, Pará, Brasil / The ethnobotanical study of Mauritia flexuosa L. f. (Arecaceae) in riverine communities of Abaetetuba county, Pará state, Brazil

Dada a relevância cultural e econômica do miriti (Mauritia flexuosa L.f.) em Abaetetuba-PA, principalmente na confecção de produtos artesanais, este trabalho teve como objetivo registrar informações a respeito do uso dado à folha desta palmeira pelas comunidades ribeirinhas de Sirituba, Tauerá, Acaraqui e Arapapuzinho, do referido município. Estas foram selecionadas durante oficina de mapeamento participativo, realizado pelo "Projeto Miriti", executado pelo Centro Internacional de Pesquisa Florestal (CIFOR). Os informantes (n=45) foram amostrados de forma probabilística, através da amostra por conglomerados. Para a coleta de dados aplicaram-se as técnicas de entrevista semi-estruturada, listagem livre, indução não-específica e observação participante. Foi calculado o valor de diversidade do informante (IDs) e o índice de Sørensen para análise de similaridade dos usos entre as comunidades. Vinte e seis produtos confeccionados foram identificados, 15 dos quais referenciados como "artesanato popular local". "Paneiro", "rasa", "tipiti", "abano", "matapi" e "peneira" foram considerados os utensílios culturalmente mais importantes. O valor de diversidade do informante (IDs) entre os entrevistados das quatro comunidades com relação à quantidade de produtos utilizados apresentou-se significativamente homogêneo. Os maiores índices de similaridade constatados foram entre as comunidades de Sirituba e Acaraqui e os menores entre Arapapuzinho e Acaraqui. O miriti possui expressiva importância para os ribeirinhos de Abaetetuba em muitos aspectos. O número de produtos identificados foi alto, e embora nem todos os objetos sejam utilizados no dia-a-dia eles possuem relevância econômica, uma vez que sua comercialização contribui para a renda dos moradores.

The miriti (Mauritia flexuosa L.f.) is of great cultural and economic importance in the county of Abaetetuba, Pará state, principally to make artisanal crafts and products. Given the significance of this species in Abaetetuba the purpose of this study was to gather information on the use of these fronds. A representative sample from four Abaetetuba communities, Sirituba, Tauerá, Acaraqui and Arapapuzinho (n=45), was selected to participate in a local mapping workshop conducted by the Miriti Project, executed by CIFOR (Centro Internacional de Pesquisa Florestal). Research was conducted through semi-structured interviews, free listing, non-specific frame elicitation and participant observation. An index value for informant diversity (IDs) was calculated and the Sørensen index was used to analyze similarity between communities. A total of 26 items were crafted from palm fronds of which 15 were cited as being popular artisanal products. "Paneiro", "rasa", "tipiti", "abano", "matapi" e "peneira" were considered the most culturally important. The IDs between informants in the four communities for the quantity of important products showed a high uniformity. The highest index of similarity was encountered between the communities of Sirituba and Acaraqui and the lowest was encountered between Arapapuzinho and Acaraqui. All told, miriti is of high value to the riverine dwellers of Abaetetuba. The number of craftwork items was high and although many of these products are not used on a daily basis, they are of distinct economic importance, as the marketing of these products contributes to the earnings of local residents.

Medicinal knowledge and plant utilization in an Amazonian coastal community of Marudá, Pará State (Brazil).

ETHNOPHARMACOLOGICAL RELEVANCE: It shows the local medicinal uses of biodiversity in Brazil's Amazonian littoral, promoting the value of folk knowledge, and its applicability in future studies. AIM OF THE STUDY: To demonstrate the importance of the knowledge of medicinal plants in the Amazonian coastal community of Marudá, located in Pará State, Brazil. MATERIALS AND METHODS: Fieldwork was conducted between 1996 and 1998, using the methods of participant observation, semi-structured interviews and informal discussions to elicit information from community residents and plant specialists, in addition to collecting plant material. RESULTS: Community residents possess knowledge of 229 medicinal plants distributed in 81 botanical families and know how to manipulate them in a variety of ways, with special care taken to ensure that they are used in the safest and most efficient manner. Therapeutic indications for these plants include illness and disease recognized in the repertoire of Western medicine as well as ailments perceived from a local cultural perspective. CONCLUSION: Results from this study attest to informants' knowledge of medicinal flora and their ability and openness to integrate new species from diverse origins into their gamut of medicinal knowledge, including industrial therapeutic preparations and animal products. Local uses of biodiversity in Brazil's Amazonian littoral are also evinced, promoting the value of folk medicinal knowledge. Similarly, it mentions the potential of implementing local knowledge in Brazil's Unitary Health System.

Gastroprotective activity of Pradosia huberi on experimentally induced gastric lesions in rodents: role of endogenous sulphydryls and nitric oxide.

Pradosia huberi is a medicinal plant very common in the Amazonian forest population. The research interest in this plant is justifiable because of its potential medicinal value in gastritis and gastric ulcer mentioned in local folk medicine. In this paper, we evaluated the acute toxicity and antiulcerogenic effect of a hydroalcoholic extract (HAE) obtained from Pradosia huberi barks in rodents. No acute toxicological sign or symptom was observed in animals treated with the highest dose (5000 mg/kg, p.o.) of Pradosia huberi. In the HCl/EtOH-induced gastric ulcer model, HAE demonstrated significant inhibition of the ulcerative lesion index by 73% (500 mg/kg) and 88% (1000 mg/kg), respectively, in relation to the control value (p<0.05). The gastric damage induced by absolute ethanol in rats was effectively reduced by 84, 88 and 81% (250, 500 and 1000 mg/kg) when compared with the control group (p<0.01). In the NSAID-induced lesion model, HAE also showed antiulcerogenic effect with decrease in gastric lesions of 56% (250 mg/kg), 57% (500 mg/kg) and 67 % (1000 mg/kg) when compared with animals treated with vehicle (p<0.05). In the gastric ulcer induced by pylorus ligature model, the administration of HAE by oral and intraduodenal routes inhibited the gastric lesion index by 79 and 52% (500 mg/kg), respectively. HAE administered orally or intraduodenally was able to change gastric juice parameters (pH, volume and acid output) as well as those treated with cimetidine. The treatment with HAE (p.o.) significantly increased gastric volume, the pH values and promoted reduced acid output (p<0.01). By comparative effect (intraduodenal and oral route), we observed that HAE was better for local activity in gastric mucosa than in systemic action. HAE also has a non-specific activity when found to be the inhibitor of intestinal motility (p>0.01). The mechanism of action of HAE did not seem to be related to the NO-inhibitor but showed the participation of endogenous sulphydryl group in the gastroprotective action.