Flavia Maria Mendonça do Amaral

Plants and chemical constituents with giardicidal activity

Intestinal infection caused by Giardia lamblia represents a serious public health problem, with increased rates of prevalence in numerous countries. Increased resistance of the parasite and the side-effects of the reference drugs employed in the treatment of giardiasis make necessary to seek new therapeutic agents. Natural products, especially of plant origin, represent excellent starting point for research. The objective of this study is to review the literature on plant extracts, fractions and chemical constituents whose giardicidal activity has been investigated in vitro. The review describes 153 (one hundred and fifty-three) plant species from 69 (sixty-nine) families that were evaluated for their giardicidal activity. The geographical distribution of the plant species, the part used, preparation, strain of Giardia lamblia tested and the results obtained by the authors are also given. One hundred and one compounds isolated from plant species, classified by chemical class, are presented. Recent aspects of research on natural products of plant origin employed in the treatment of giardiasis are also discussed.

Avaliação da atividade leishmanicida in vitro de plantas medicinais

Searching for new leishmanicidal agents, promastigotes forms of L. amazonensis were cultured with the hydroalcoholic extracts obtained from the Tephrosia cinerea (L.) Pers. (Fabaceae), Dichorisandra sp (Commelinaceae), Syzygium jambolanum DC. (Myrtaceae), Julocroton triqueter (Lam.) Didr. var. triqueter (Euphorbiaceae), Passiflora edulis Sims(Passifloraceae), Cecropia sp (Cecropiaceae), Chenopodium ambrosioides L.(Chenopodiaceae), Pedilanhus tithymaloides (L.) Poit (Euphorbiaceae), Peristrophe angustifolia Nees(Acanthaceae) leaves and the aqueous extract obtained from the Orbignya phalerata Mart. (Arecaceae) mesocarp flour. The in vitro assay was performed with promastigotes incubated during 24 hours with 31.3, 62.5, 125.0, 250.0 and 500.0 µg/mL of each extract. Then the inhibitory concentration of the parasite growth (IC50) was determined. The effectiveness of J. triqueter, Dichorisandra sp and T. cinerea hydroalcoholic extracts to induce promastigotes death was intense since the IC50 were 29.5; 32.9 and 43.6 µg/mL, respectively. P. edulis, C. ambrosioides and S. jambolanum extracts had moderated effectiveness since the IC50 were 150.1; 151.9 and 166.6 µg/mL, respectively. P. tithymaloides and O. phalerata extracts showed a low efficacy in comparison with IC50 >500 µg/mL. Peristrophe angustifolia and Cecropia sp extracts had no leishmanicidal effect. Thus, three of the ten extracts that were tested showed a significant in vitro leishmanicidal activity.

Avaliação da qualidade de drogas vegetais comercializadas em São Luís/Maranhão

Qualitative analysis of plants commercialized for medical purposes in public markets in Sao Luis/MA. Its made a research on strange materials, evaluation of macroscopic characteristics, determination of humidity level and research on microbiological contamination, this way proving the bad quality of vegetable material available for the population in Maranhao state.

Molluscicidal and larvicidal activities and essential oil composition of Cymbopogon winterianus

Abstract Context. Cymbopogon winterianus Jowitt ex Bor (Poaceae), known as citronella grass, is an aromatic herbaceous plant and the essential oil extracted from this grass is used in cosmetics, perfumes, hygiene and cleanliness products worldwide. Objective: This study investigated the composition and molluscicidal and larvicidal activities of the essential oil of C. winterianus cultivated in North Brazil. Materials and methods: The oil was obtained by hydrodistillation, analyzed by gas chromatography (GC) and GC-mass spectrometry and then its molluscicidal and larvicidal activities against snails (Biomphalaria glabrata) and hatched larvae of Artemia salina, respectively, were evaluated at concentrations from 10 to 1000 mg/L. Results: The main constituents of oil were citronellal (26.5%), geraniol (16.2%), elemol (14.5%) and citronellol (7.3%). The molluscicidal test revealed significant lethal concentration (LC) values (LC90 = 97.0 mg/L, LC50 = 54.0 mg/L and LC20 = 22.0 mg/L), indicating the presence of molluscicidal compounds in the oil. In addition, the oil showed moderate larvicidal activity (LC50 = 181.0 mg/L) against the larvae of A. salina, which could justify its use in the aquatic environment without affecting other living organisms. Discussion and conclusion: The results suggest that the oil of C. winterianus could be an effective alternative to control schistosomiasis, with an average margin of safety to other living organisms that coexist with snails.

Chemical Composition and Larvicidal Activity of Essential Oils Extracted from Brazilian Legal Amazon Plants against Aedes aegypti L. (Diptera: Culicidae)

The mosquito Aedes aegypti L. (Diptera: Culicidae) is the major vector of dengue and chikungunya fever. The lack of effective therapies and vaccines for these diseases highlights the need for alternative strategies to control the spread of virus. Therefore, this study investigated the larvicidal potential of essential oils from common plant species obtained from the Chapada das Mesas National Park, Brazil, against third instar A. aegypti larvae. The chemical composition of these oils was determined by gas chromatography coupled to mass spectrometry. The essential oils of Eugenia piauhiensis Vellaff., Myrcia erythroxylon O. Berg, Psidium myrsinites DC., and Siparuna camporum (Tul.) A. DC. were observed to be mainly composed of sesquiterpene hydrocarbons. The essential oil of Lippia gracilis Schauer was composed of oxygenated monoterpenes. Four of the five tested oils were effective against the A. aegypti larvae, with the lethal concentration (LC50) ranging from 230 to 292 mg/L after 24 h of exposure. Overall, this work demonstrated the possibility of developing larvicidal products against A. aegypti by using essential oils from the flora of the Brazilian Legal Amazon. This in turn demonstrates the potential of using natural resources for the control of disease vectors.

Chenopodium ambrosioides L. Reduces Synovial Inflammation and Pain in Experimental Osteoarthritis

The chronicity of osteoarthritis (OA), characterized by pain and inflammation in the joints, is linked to a glutamate receptor, N-methyl-D-aspartate (NMDA). The use of plant species such as Chenopodium ambrosioides L. (Amaranthaceae) as NMDA antagonists offers a promising perspective. This work aims to analyze the antinociceptive and anti-inflammatory responses of the crude hydroalcoholic extract (HCE) of C. ambrosioides leaves in an experimental OA model. Wistar rats were separated into six groups (n = 24): clean (C), negative control (CTL-), positive control (CTL+), HCE0.5, HCE5 and HCE50. The first group received no intervention. The other groups received an intra-articular injection of sodium monoiodoacetate (MIA) (8 mg/kg) on day 0. After six hours, they were orally treated with saline, Maxicam plus (meloxicam + chondroitin sulfate) and HCE at doses of 0.5 mg/kg, 5 mg/kg and 50 mg/kg, respectively. After three, seven and ten days, clinical evaluations were performed (knee diameter, mechanical allodynia, mechanical hyperalgesia and motor activity). On the tenth day, after euthanasia, synovial fluid and draining lymph node were collected for cellular quantification, and cartilage was collected for histopathological analysis. Finally, molecular docking was performed to evaluate the compatibility of ascaridole, a monoterpene found in HCE, with the NMDA receptor. After the third day, HCE reduced knee edema. HCE5 showed less cellular infiltrate in the cartilage and synovium and lower intensities of allodynia from the third day and of hyperalgesia from the seventh day up to the last treatment day. The HCE5 and HCE50 groups improved in forced walking. In relation to molecular docking, ascaridole showed NMDA receptor binding affinity. C. ambrosioides HCE was effective in the treatment of OA because it reduced synovial inflammation and behavioral changes due to pain. This effect may be related to the antagonistic effect of ascaridole on the NMDA receptor.

Composição química e toxicidade frente Aedes aegypti L. e Artemia salina Leach do óleo essencial das folhas de Myrcia sylvatica (G. Mey.) DC.

Dengue is among the most important viral diseases of vector spread in the world, causing serious impacts of morbidity and mortality. Thus, this study aimed to analyze the chemical composition and toxicity of the Myrcia sylvatica (G. Mey.) DC essential oil against Aedes aegypti and Artemia salina Leach. Leaves of M. sylvatica. were collected in the Tables Chapada National Park, in the municipality of Carolina (MA) in february 2012. The oil was obtained by hydrodistillation and their chemical composition was determined by GC / MS. The bioassay front and Artemia salina larvae of the 3° stage of Aedes aegypti were performed at different concentrations. Mortality data were evaluated by linear regression to determine the LC50. Was obtained 0.5% yield values, and (E) -caryophyllene the major constituent. The essential oil showed a LC50 = 79.44 mg / mL front A. saline and is considered highly toxic. However, this oil showed no effect on larvae of A. aegypti. Whereas the brine shrimp test has regard to several biological activities, as antitumoral property, the essential oil from the leaves of M. sylvatica demonstrated potential for development of medicines.

Uso de plantas com finalidade medicinal por pessoas vivendo com HIV/ AIDS em terapia antirretroviral

Este foi um estudo observacional, transversal analitico realizado em ambulatorio de referencia do Estado do Maranhao-Brasil, no periodo de maio de 2009 a fevereiro de 2010, com o objetivo de estudar o uso de plantas com finalidade medicinal entre pessoas vivendo com HIV/AIDS, em uso de antirretrovirais. Um total de 339 pessoas respondeu um questionario abordando o uso de plantas e caracteristicas demograficas, socioeconomicas, comportamentais, relacionadas a soropositividade e ao uso de antirretrovirais. A prevalencia de utilizacao de plantas foi de 34,81%. As mais utilizadas foram: Turnera ulmifolia (12,09%); Melissa officinalis (10,62%); Plectranthus barbatus (7,67%); Cymbopogan citratus (capim limao) (4,72%) e Mentha spp. (hortela) (2,36%). A maioria das pessoas (96,61%) referiu melhora apos a utilizacao. Um percentual de 75,42% dos usuarios de plantas nao informou essa pratica ao medico. Entre os que informaram o uso, 55,17% afirmaram que o medico estava de acordo e somente uma pessoa foi orientada a interromper o uso (3,45%). Apenas um medico (3,45%) indicou o uso de plantas. A analise ajustada evidenciou diferenca para uso de plantas em relacao ao sexo feminino (RP=1,58, 95% IC 1,15-2,15 p 0,004) e a orientacao sexual do tipo homossexual (RP=0,63 IC 0,44-0,90 p 0,012). Este estudo aponta para a necessidade de melhor dialogo entre medico e pacientes sobre o uso de plantas com finalidade medicinal, alertando sobre possiveis perigos quando associados aos antirretrovirais, especialmente entre usuarios do sexo feminino ou com pratica do tipo homossexual.

Plantas e constituintes químicos empregados em Odontologia: revisão de estudos etnofarmacológicos e de avaliação da atividade antimicrobiana in vitro em patógenos orais

Products derived from plants may represent a promising strategy in dentistry. Thus, the objective of this paper is to review studies of the popular use of plants in oral diseases, as well as studies evaluating the in vitro antimicrobial activity of plant extracts and isolated compounds in oral pathogens from 1996 to 2011. Forty-seven botanical families were mentioned, with the highest number of referencesfor Anacardiaceae, and Anacardium occidentale L. was the most mentioned specie. The review of antimicrobial activity studies relatedextracts from sixty-six plant species belonging to thirty-eight botanical families, especially Anacardiaceae, being predominant tests with leaves, investigated by the agar diffusion method. Fifty-eight compounds isolated from plants have been evaluated, showing that Terminalia chebula Retz (Combretaceae) represents the plant species with more meaningful in vitro antimicrobial activity, with inhibition zone of 32.97 mm against Staphylococcus aureus, microorganism found in oral infections, while tetra iso-alpha acid isolated from Humulus lupulus L. (Canabinaceae) showed greater inhibition zone for Streptococcus mutans (26.0 mm). The presented results should encourage the development of validation studies, ensuring the safe and effective use of plant species in dentistry.

Chenopodium ambrosioides L. Improves Phagocytic Activity and Decreases Bacterial Growth and the Systemic Inflammatory Response in Sepsis Induced by Cecal Ligation and Puncture

Chenopodium ambrosioides L. (Amaranthaceae) is often used in different kinds of vegetal preparations for medicinal purposes in many clinical situations. Some studies have demonstrated its anti-inflammatory and immunomodulatory properties. The aim of this work was to investigate the effect of prophylactic treatment with the hydroalcoholic crude extract (HCE) of C. ambrosioides and its hexanic fraction (HEX) on the control of bacterial growth, the activation of phagocytes and the control of the systemic inflammatory response in a sepsis experimental model. Animals were divided into three groups (n = 5/group): Control, which received only NaCl 0.9% solution; HCE, which received the crude extract; and HEX, which received the HEX of the extract. The animals received saline, HCE or HEX (5 mg/kg), subcutaneously (SC), 6 h before cecal ligation and puncture (CLP). Twelve hours after the CLP, the blood was collected to measure the serum cytokines and the animals were killed for the evaluation of colony-forming units (CFUs), cellular influx, and activation of phagocytes in the peritoneal cavity, measured by the secretion of hydrogen peroxide and nitric oxide production. The results showed that only HEX treatment inhibited bacterial growth in the peritoneum and inflammatory cellular influx, especially influx of macrophages and neutrophils. However, HCE and HEX treatments increased ex vivo hydrogen peroxide secretion and nitric oxide production by phagocytes and decreased the pro-inflammatory cytokines in the serum, indicating a systemic anti-inflammatory effect of both. In conclusion, C. ambrosioides treatment decreases bacterial growth likely by activation of phagocytes and, in parallel, ameliorates the general state of mice by reducing the systemic inflammatory response usually observed in sepsis.