Actividad antiplasmodial de plantas usadas en la medicina tradicional contra la malaria en Cuba / Antiplasmodial activity of plant species used in traditional medicine for the control of malaria in Cuba

Introducción: Las plantas utilizadas en la medicina tradicional se exploran internacionalmente como fuentes valiosas de nuevos agentes antipalúdicos. Objetivos: Evaluar la actividad inhibidora in vitro frente a Plasmodium berghei de extractos de 27 especies de plantas utilizadas en el siglo pasado contra la malaria en Cuba, valorando los precedentes de estudios científicos de estas especies. Métodos: Se prepararon extractos etanólicos de 27 especies de plantas que se evaluaron in vitro a través de la inhibición de la esquizogonia de P. berghei ANKA. Se realizó una revisión basada en la consulta de artículos científicos para la clasificación de actividad basada en rangos de CI50. Resultados: Dieciséis especies mostraron precedentes de actividad inhibidora in vitro o su utilización en la medicina tradicional de otros países; siete especies no mostraron actividad coincidente. Solamente los extractos hidroalcohólicos de Euphorbia tithymaloides L. (partes aéreas) y Swietenia mahagoni (L.) Jacq. (corteza) fueron activos con CI50 ≤ 5 µg/mL, mientras para Colubrina arborescens (Mill.) Sarg. (corteza), la CI50 fue 14,3 ± 1,9 µg/mL. Extractos de 11 especies se probaron por el interés de su utilización en Cuba, sin precedentes etnobotánicos y experimentales disponibles. Entre estos, las partes aéreas de Baccharis halimifolia L. var. angustior DC; y de Oxandra lanceolata (Sw.) Baill. constituyeron fuentes antiplasmodiales de valores moderados de CI50. El resto de los extractos no fueron activos. Conclusiones: Estos resultados apoyan el uso en medicina tradicional en Cuba contra malaria de E. tithymaloides, S. mahagoni, C. arborescens, B. halimifolia y O. lanceolata, lo cual estimula a ampliar su estudio.

Introduction: Plants used in traditional medicine are studied worldwide as valuable sources of new antiplasmodial agents. Objective: To evaluate the in vitro inhibitory activity against Plasmodium berghei of extracts from 27 plant species used in the last century against malaria in Cuba and assess the previous scientific studies on these species. Methods: Ethanolic extracts from 27 plant species were prepared and evaluated in vitro by inhibiting the schizogony of P. berghei ANKA. A review of scientific papers was conducted to classify the activity based on IC50. Results: Sixteen species showed precedents of inhibitory activity in vitro or of their use in traditional medicine in other countries; seven species did not show coincident activity. Only hydroalcoholic extracts from Euphorbia tithymaloides L. (aerial parts) and Swietenia mahagoni (L.) Jacq. (bark) displayed activity at IC50 ≤ 5 µg/mL, while for Colubrina arborescens (Mill.) Sarg. (bark) IC50 was 14.3 ± 1.9 µg/mL. Extracts from 11 species, with no ethnobotanical and experimental precedents available, were evaluated given the interest of their use in Cuba. Of these species, the aerial parts of Baccharis halimifolia L. var. angustior DC and Oxandra lanceolata (Sw.) Baill. constituted antiplasmodial sources of moderate IC50 values. The rest of the extracts were not active. Conclusions: These results support the use of E. tithymaloides, S. mahagoni, C. arborescens, B. halimifolia y O. lanceolata in traditional medicine against malaria in Cuba, which stimulate further studies.

Steroids from Diplazium esculentum: Antiplasmodial activity and molecular docking studies to investigate their binding modes

@#Diplazium esculentum is an edible fern commonly consumed by the local community in Malaysia either as food or medicine. Isolation work on the ethyl acetate extract of the stem of D. esculentum resulted in the purification of two steroids, subsequently identified as stigmasterol (compound 1) and ergosterol5,8-endoperoxide (compound 2). Upon further testing, compound 2 displayed strong inhibitory activity against the Plasmodium falciparum 3D7 (chloroquine-sensitive) strain, with an IC50 of 4.27±1.15 µM, while compound 1 was inactive. In silico data revealed that compound 2 showed good binding affinity to P. falciparum-Sarco endoplasmic reticulum calcium-dependent ATPase (PfATP6); however, compound 1 did not show an antiplasmodial effect due to the lack of a peroxide moiety in the chemical structure. Our data suggested that the antiplasmodial activity of compound 2 from D. esculentum might be due to the inhibition of PfATP6, which resulted in both in vitro and in silico inhibitory properties.

Characterization of Malaria Preventive Extracts from Myrsine africana Seeds

Introduction:The use of pharmaceutical anti-malaria drugs in many rural areas is not common. Various plant extracts have been used as anti-plasmodial agents.Myrsine africanaseed extracts are common anti-malaria agents amongst the Maasai community of Kenya.Aims:This study aimed at characterizing the chemical constituents of methanolic, aqua and n-hexane extracts of Myrsine africana seeds. Study Design:An independent measures design was used.Methodology:The extracts were obtained by maceration of the seeds before subjecting to physical-chemical analysis, functional groups, bio-metal concentrations and phytochemicals screening. Antibacterial studies were conducted using E. coliand S. aureus. The extracts were thereafter screened for presence of quinine and chloroquine by UV VIS spectroscopy. Results:The results indicated the extracts were weakly acidic with moderate solid content. The FT-IR peaks of the extracts indicated abundance of carboxylic acids and benzylic groups. The extracts had a moderate iron concentration with mild copper, cobalt and zinc concentrations. The extracts were also rich in tannins, phenols, saponins, alkaloids and steroids. The antibacterial proficiency of both stains used increased with concentration of extracts and were highest at 50.0mg/mL. Methanolic and water extracts of the seeds also showed appreciable quinines and chloroquinines concentrations. Conclusions:M. africanaseed methanolic and water extracts can be used as anti-plasmodial drugs to help curb malaria in rural tropical regions

In vitro and in vivo antimalarial activity of the volatile oil of Cyperus articulatus (Cyperaceae)

Malaria is a disease of global tropical distribution, being endemic in more than 90 countries and responsible for about 212 million cases worldwide in 2016. To date, the strategies used to eradicate this disease have been ineffective, without specific preventive measures such as vaccines. Currently, the existing therapeutic arsenal is limited and has become ineffective against the expansion of artemisinin-resistant Plasmodium, demonstrating the need for studies that would allow the development of new compounds against this disease. In this context, we studied the volatile oil obtained from rhizomes of Cyperus articulatus (VOCA), a plant species commonly found in the Amazon region and popularly used as a therapeutic alternative for the treatment of malaria, in order to confirm its potential as an antimalarial agent by in vitro and in vivo assays. We cultured Plasmodium falciparum W2 (chloroquine-resistant) and 3D7 (chloroquine-sensitive) strains in erythrocytes and exposed them to VOCA at different concentrations in 96-well microplates. In vivo antimalarial activity was tested in BALB/c mice inoculated with approximately 106 erythrocytes infected with Plasmodium berghei. VOCA showed a high antimalarial potential against the two P. falciparum strains, with IC50 = 1.21 µg mL-1 for W2 and 2.30 µg mL-1 for 3D7. VOCA also significantly reduced the parasitemia and anemia induced by P. berghei in mice. Our results confirmed the antimalarial potential of the volatile oil of Cyperus articulatus. (AU)

Phytochemical Analysis and Antiplasmodial (curative) Activities of Methanolic Leaf Extract of Morinda lucida (Ewe Oruwo) in Male Swiss Mice Infected with Plasmodium berghei NK65

Aim:Medicinal plants have been used for the treatment of many infections and diseases including malaria. The study was conducted to determine the effect of in vivoanti-plasmodialand antioxidant properties of the methanolic leaf extract of Morinda lucidain male Swiss albino mice infected with Plasmodium Berghei NK65. Study Design and Methodology:Phytochemical, GC-MS and AAS analyses were determined in the plant. Swiss albino mice were inoculated intraperitoneally with Plasmodium bergheiNK65. Thirty-five (35) mice were grouped into seven groups, five per group. Group A were not infected with P.bergheiNK65.Group B, C and D served as the negative and positive control groups while Group E, F and G mice were treated with 400, 600 and 800 mg/kg body weight of methanolic leaf extract of M. lucida. Haematological parameters were determined in the whole blood using BC-3200 Auto Hematology Analyzer. TP, MDA, CAT, SOD % inhibition, SOD unit and vitamin A were all determined in the liver homogenateusing standard procedures.Results:The GC-MS result of the M. lucidashows the presence of five bioactive compounds. It was also observed that the plant contains the following minerals: iron, magnesium, potassium, phosphorus and copper. Acute toxicity shows that the LD50>000mg/Kg b.wt. The extract caused 30.96%, 32.93% and 67.23% reduction in parasitemia at 400, 600 and 800 mg/kg body weight respectively while chloroquine exerted 96.53% and artesunate exerted 92.03% reduction at 10 mg/kg body weight respectively. The Haematological parameters showed that the plant extractis nothaematotoxic since it significantly (P<0.05) reduced WBC count, and increase RBC, HGB, and HCT values in the treated mice compared to the infected untreated mice. This study shows that the mean lipid peroxidation (MDA) level was significantly decreased in the malaria treated mice (group C, D, E, F and G) compared to the untreated mice (group B). There was also a significant increase in the total protein, catalase, SOD % inhibition, SOD unit and Vitamin A levels in the liver homogenate of animals treated with chloroquine, artesunate and extract of M. lucidacompared to the untreated mice. Conclusions: The study shows that Morinda lucidapossess antiplasmodial activity in male Swiss mice infected with Plasmodium berghei NK 65.

Antiplasmodial, Antipyretic, Haematological and Histological Effects of the Leaf Extracts of Moringa oleifera in Plasmodium berghei berghei Infected Mice

Theaqueous and ethanolic extracts of Moringa oleiferaleaf were evaluated for safety, antimalarial and antipyretic activities because it is commonly used for various types of ailments especially malaria and fever. The various concentration of these extracts (0-800mg/kg) were tested against Plasmodium berghei bergheiinfectedalbino mice of either sex, in a Peters’four day antiplasmodialtest while antipyretic activities were evaluated in malaria-induced mice. Their possible effects on haematological parameters of PCV, WBC, neutrophil, lymphocytes count and liver enzymes were also determined as well as on the liver and kidney architecture. All the tested doses of the aqueous extract were comparable in antiplasmodial activity (p>0.05) to each of the tested doses of the ethanolic extract which were significantly different (p<0.05) from the negative control. Only the highest doses of both extracts gave significantly higher (p<0.05) antiplasmodial activity than the standard drug. For the ethanolic extract,a significant antipyretic activity was not observed until at 800mg/kg in time T3while the aqueous extract exerted no significant antipyretic activity at all doses and at all times. The ethanolic extract gave significantly higher PCV values than that of the aqueous. The administration of the aqueous extract gave significantly lower WBC than the ethanolic extract while comparable increase in lymphocyte count was noticeable at each of the doses of both extracts when compared to the negative control. Only 100mg/kg and 800mg/kg of the aqueous extract maintained a relatively high neutrophils count in this study. Also, the aqueous extract elicited higher concentration of ALT (greater than fourfold of normal) but the ethanolic extract produced the highest level of AST at the highest dose of 800mg/kg when compared to the ethanolic extract. Histological examination of the kidney showed progressive degeneration while that of the liver showed recovery when compared to negative control as a result of progressive increase in dosage of the extracts in malarial treatment.In conclusion, though both aqueous and ethanolic extracts of M. oleiferaleaves exert chemosuppressive antiplasmodial activities in Plasmodium berghei bergheiinfected mice and exhibited antipyretic activity with some improved haematological parameters, caution should be taken in its indiscriminate use because of probable toxic effects on thekidney and the liver.

Antiplasmodial evaluation of Anacardium occidentale and alkyl-phenols

Abstract The ethanol crude extract from cashew (Anacardium occidentale L. Anacardiaceae) displayed significant antiplasmodial activity (IC50 0.577 µg/ml). Liquid chromatography-high resolution Mass spectrometry analysis was performed to identify the main compounds existing in the ethanol extract. The occurrence of anacardic acids, cardols, and 2-methylcardols derivatives was confirmed in the extract. The IC50 obtained, when the main isolated compounds were evaluated in Plasmodium falciparum D6 strain, ranged from 5.39 µM to >100 µM. Tested here for the first time, the data showed that cardol triene 1 (IC50 = 5.69 µM) and 2-methylcardol triene 4 (IC50 = 5.39 µM) demonstrated good antimalarial activity. In conclusion, Anacardium occidentale nuts presented relevant biological potential, and further studies should be considered.

In vivo antiplasmodial potential of three herbal methanolic extracts in mice infected with Plasmodium berghei NK65 / 中草药·英文版

Objective: The present study deals with the investigation of antiplasmodial potential of leaf methanolic extract of Aegle marmelos, Aristolochia indica and Cassia auriculata against Plasmodium berghei (NK65) infected mice. Methods: The chloroquine-sensitive parasites P. berghei (1 × 106) were inoculated into Swiss albino mice intraperitoneally. The methanol extracts of three herbal plants were orally administered in P. berghei infected mice which were further assessed using the four-day suppressive test at different doses of 150, 300 and 600 mg/kg per day. Chloroquine (CQ) was used as the standard drug with of 1.25, 2.5 and 5 mg/kg concentrations and was orally administered. Results: The leaves of A. marmelos, A. indica, and C. auriculata were found to suppress P. berghei parasitaemia in Swiss albino mice by (67.0 ± 4.02)%, (72.0 ± 8.44)% and (52.7 ± 2.06)% at 600 mg/kg/d with ED50 values of 284.73, 233.77 and 562.48 mg/kg, respectively. These herbal plants increased the mean survival time of infected mice and prevented body weight loss. GC-MS analysis revealed the presence of hentriacontan-16-one (C31H62O) in A. indica extract. The histopathology study showed non-toxic to kidney and liver at 600 mg/kg/body weight. Conclusions: Overall results revealed that herbal plants may be active in the development of novel and cheap antimalarial compounds.

Antibacterial and Antiplasmodial Activities of Tannins Extracted from Zizyphus mauritiana in Mali

Aim: This study was designed to evaluate tannins extracted from Ziziphus mauritiana as source of potential antimalarial and antimicrobial agents in Mali.Place and Duration of Study: Collection of plant materials, tannins extraction, antibacterial activity evaluation were done at University od Sciences, Techniques and Technologies of Bamako, Mali and antiplasmodial activity assessment at Department of Microbiology and Immunology, WeillCornell Medicine, New York, United States of America between September 2013 and February 2014Methods: We extracted tannins from leaves of Z. mauritiana collectedaround Bamako, Mali. Antiplasmodialactivity was evaluated against 3D7 (chloroquine-sensitive) and Dd2 (chloroquine-resistant) strains of Plasmodium falciparumusing the fluorescence based SYBR® green I method. Antibacterial activity of tannins was evaluated by disc diffusion method againststrains of Escherichia coli, Salmonella Typhi, Streptococcus andStaphylococcus aureus donated by the National Research Institute in Public Health in Mali and collected from infected patients suffering from different diseases.Results: Tannins extracts from leaves of Z. mauritiana showed moderate antiplasmodial activity against 3D7 P. falciparum (46.9±1.12 ?g/mL) and against Dd2 P. falciparum strains (67.8±2.39?g/mL). They showed also an antibacterial activity on different bacterial strains showing important inhibition zones. Conclusion: Tannins extractedfrom Z. mauritiana demonstrated good antiplasmodial and antibacterial activities.These data confirm the potential use of tannins as a key element in antimalarial and antibacterial drug development.

Inhibición de la formación de ß-hematina de especies colombianas de Piper spp. y Calophyllum spp. como potenciales agentes antimaláricos / Inhibition of ß-hematin formation of Colombian species of Piper spp. and Calophyllum spp. as potential antimalarial agents

Resumen Nuevos agentes antimaláricos a partir de plantas son estudiados como alternativas en el tratamiento de la malaria. Los principales antimaláricos como la cloroquina tienen varios mecanismos de acción contra parásitos, uno de ellos es la inhibición de polimerización del grupo hemo, modelo que ha permitido el diseño de nuevos candidatos antimaláricos. En este sentido, el objetivo de este trabajo fue evaluar extractos de plantas de género Piper y Calophyllum sobre la capacidad de inhibición de la β-hematina. Se informa las concentraciones inhibitorias de la formación de β-hematina por parte de 40 extractos de diferente polaridad obtenidos a partir de las especies P. piedecuestanum, C. brasiliense, C. longinforium, y Calophyllum. sp. 19 extractos mostraron un mayor potencial para inhibir la formación de β−hematina con CI50 < 3mg / ml. Estas actividades respaldan principalmente, futuros estudios con el género Calophyllum, en el desarrollo y descubrimiento de nuevas sustancias antiplasmodiales con modos de acción conocido.(AU)

Abstract New antimalarial agents from plants are studied as alternatives in the treatment of malaria. The main antimalarials such as chloroquine have several mechanisms of action against parasites, one of which is the inhibition of polymerization of the heme group, a model that has allowed the design of new antimalarial candidates. In this sense the objective of this work was to evaluate extracts of genus Piper and Calophyllum plants on the inhibition capacity of β-hematin. Inhibitory concentrations of β-hematin are reported from 40 extracts of different polarity obtained from the species P. piedecuestanum, C. brasiliense, C. longinforium, and Calophyllum. sp. 19 extracts showed a greater potential to inhibit β-hematin with IC50 < 3 mg/ml. These activities mainly support future studies with the genus Calophyllum in the development and discovery of new antiplasmodial substances with known modes of action.(AU)

In vivo Anti-plasmodial Activity of Crude Extracts of Three Medicinal Plants Used Traditionally for Malaria Treatment in Kenya

The aim of the study was to determine the in vivo anti-plasmodial activity of three plants Rhamnus prinoides, Rubus keniensis and Garcinia buchananii which are used for malaria treatment by indigenous communities in Kenya. This work was done at the Department of Biological and Preclinical studies, Institute of Traditional Medicine, Muhimbili University of Health & Allied Sciences in October 2016 to August 2017. Male and female albino mice were infected with Plasmodium berghei (ANKA) in the Peter’s four day suppression test. Five groups of mice; Group 1 (solvent: 5 mL/kg body weight of 1% carboxymethyl cellulose), Group 5 (10 mg/kg body weight chloroquine), Groups 2, 3 and 4 were given 200, 400 and 800 mg/kg body weight of plant extracts. The results showed that 5% aqueous methanol extracts of R. prinoides, G. buchananii and R. keniensis exhibited higher anti-plasmodial activity than the 1:1 dichloromethane: methanol extracts in the preliminary testing. The doses showing 50% parasite suppression (EC50) were 139.2, 169.4 and 245.1 mg/kg body weight for R. prinoides, G. buchananii and R. keniensis, respectively. In vivo anti-plasmodial activity of the three plants has supported the traditional use of extracts of Rhamnus prinoides, Rubus keniensis and Garcinia buchananii for treatment of malaria. Isolation of compounds from these plants is in progress.

In vitro Antiplasmodial and Toxicity Activities of Crude Extracts and Compounds from Euclea latideus (Ebenaceae)

Aims: In our search for new antiplasmodial agents, in vitro antiplasmodial activities of the crude extracts and isolated pure compounds were determined. In addition to the in vitro assays, in vivo acute toxicity of the crude extracts was investigated to assess the safety of the plants. Furthermore, structure elucidation of the pure compounds was also carried out to determine the identity of the isolated compounds.Study Design: Extraction of the root crude extracts of Euclea latideus was done using four solvents: hexane, dichloromethane, ethyl acetate and methanol. Isolation and purification were carried out on only the dichloromethane and ethyl acetate crude extracts.Methodology: Four solvent; hexane, dichloromethane, ethyl acetate and methanol were used to carry out the extraction process of the crude samples. Isolation and purification of crude extracts were achieved using chromatographic techniques which included column and thin layer chromatography (TLC). The characterization of the isolated compounds was determined using NMR spectroscopic techniques. In vitro antiplasmodial activity was performed on two strains of Plasmodium falciparum (chloroquine [CQ]-sensitive 3D7 and CQ-resistant Dd2 strains) using a non-radioactive fluorescence-based SYBR Green 1 assay technique. Lorke's method of acute toxicity was used to determine the in vivo acute toxicity of the crude extracts in mice.Results: Results of acute toxicity studies showed that all crude extracts of E. latideus had LD50 > 5000 mg/kg and therefore regarded as a non-toxic plant. The four crude extracts of E. latideus had good activityWith range of (IC50) 3D7: (9.75-38.21) µg/mL and Dd2: (2.78-38.93) µg/mL. The resistance indices for E. latideus crude extracts ranged between 0.10- 1.43, suggesting that some of the extracts had equal promise against the CQ resistant strain of P. falciparum. Isolation resulted in the identification of three known compounds which include; three triterpenoids Lupeol (EL1), betulin (EL2), 3?-(5-hydroxyferuloyl)lup-20(30)-ene (EL3 ). Among the pure compounds EL2 had the highest activity against on both strains (IC50) 3D7: 1.64 ± 0.02 µg/mL and Dd2: 7.69 ± 1.21 µg/mL while Lupeol (EL1) displayed moderate activity with (IC50) 3D7: 23.91 ± 0.05 µg/mL, Dd2: 25.14 ± 0.01 µg/mL. The antiplasmodial activity of the crude extracts and pure compounds were significantly different (P < 0.05) from that of the reference standards (chloroquine diphosphate and mefloquine hydrochloride). Both the crude extracts IC50 (2.78-38.93) µg/mL and pure compounds IC50 (1.64-25.14) µg/mL showed a significant decrease in activity compared to the reference standards (0.0056-0.0440) µg/mL. Significant difference (P < 0.05) also existed between the antiplasmodial activities of the crude extracts, which showed the same trend with that of the pure compounds.Conclusion: The results show that the root crude extracts and pure compounds of the plant have good antiplasmodial activity and low toxicity which can be exploited for malaria therapy. Therefore, this justifies their ethnomedicinal use of the plant by the local communities of Butebo Sub-County, in Pallisa District in Eastern Uganda in the treatment of malaria.

Evaluation of Antiplasmodial Activity and Safety of Flower Extracts of Chrysanthemum cinerariaefolium, Singly and in Combination with Chloroquine, Lumefantrine and Piperaquine

Objective: To evaluate the antiplasmodial activity and safety of organic and aqueous flower extracts of Chrysanthemum cinerariaefolium from Kenya, singly and in combination with chloroquine, lumefantrine and piperaquine. Methodology: Antiplasmodial activity of organic and aqueous flower extracts of C. cinerariaefolium was assessed in vitro by serial micro-dilution assay technique against Plasmodium falciparum, and in vivo using the 4-day suppressive test as well as the established infection test against P. berghei ANKA in mice. To determine the safety of the extracts, cytotoxicity evaluation of extracts against Vero E6 cells and acute toxicity studies in mice were also done. Results: In vitro antiplasmodial assays showed that methanolic extract of C. cinerariaefolium flowers was active, petroleum ether extract was moderately active, while the aqueous extract was inactive. Methanolic extract combined with chloroquine (CQ) against CQ-sensitive (3D7) and CQ-resistant (W2) P. falciparum showed marked synergy. Both methanol and aqueous extracts (1000mg/kg) showed chemosuppression of >45% (P<0.05) in both 4-day suppression test and established infection test against P. berghei ANKA in mice. Lumefantrine (LU) or piperaquine (PQ) combined with either methanol or aqueous extracts showed chemosuppression of >63% (P<0.05) against LU-resistant and PQ-resistant P. berghei ANKA strains, indicating synergistic interactions. Methanolic and aqueous flower extracts of C. cinerariaefolium had no cytotoxic effect on Vero E6 cells and no overt signs of toxicity in mice. Conclusion: The findings showed that C. cinerariaefolium flower extracts are safe in mammalian systems, have antiplasmodial activity and have potentiation effect of conventional antimalarials. There is need therefore to further explore the plant’s bioactive molecules which may serve as template for development of novel, effective and affordable antimalarial agents for management of malaria.

Antiplasmodial activity of silver nanoparticles: A novel green synthesis approach

Objective: To synthesize silver nanoparticles using silver nitrate by a green technique which involves different compositions of aqueous leaf extracts of Azadirachta indica (neem) and Ocimum sanctum (tulsi). Methods: Their shape and size were determined using transmission electron microscopy and UV-visible spectroscopy. Their antiplasmodial activity was studied using the malarial parasite strain (Plasmodium falciparum, 3D7). The parasite strain (3D7) was col ected and revived in vitro using Trager and Jensen method in RPMI 1640 medium for 7-8 cycles. Half maximal effective concentration values were calculated by nonlinear regression analysis. Results: Transmission electron microscopy results confirmed the formation of silver nanoparticles with size ranging from 4.74-39.32 nm and their size differs by varying the concentrationsfrom20％to100％ofneemextractinneemandtulsiextracts.Itwasobservedthat samples B and C showed half maximum effective concentration of about 0.3μM. Conclusions:It can be easily established that the aqueous leaf extracts of neem and tulsi in combination can be a good source for synthesis of silver nanoparticles with smal size possessing appreciable antiplasmodial activity.

Ethnobotanical database based screening and identification of potential plant species with antiplasmodial activity against chloroquine-sensitive (3D7) strain of Plasmodium falciparum

Objetive:To evaluate the antiplasmodial activity of aqueous-methanolic plant extracts of nine plant species selected,based on ethnobotanical data.Methods:Based on ethnobotanical database,the selected plants were tested for their antiplasmodial activity against chloroquinesensitive (3D7) strain of Plasmodium falciparum.Qualitative tests and high performance thin layer chromatography analysis were carried out to explore the phytocomponents present in the plant extracts.1,1-diphenyl-2-picrylhydrazyl antioxidant activity was also determined to check the antioxidant activity of the plant extracts.Results:Moringa oleifera (IC50:3.906 μg/mL),Acalypha indica (IC50:3.906 μg/mL),Hyptis suaveolens (IC50:3.906 μg/mL),Mangifera indica (IC50:4.150 μg/mL) and Averrhoa bidimbi (IC50:4.881 μg/mL) showed very good antiplasmodial activity.Conclusions:Crude extracts of Mangifera indica and Hyptis suaveolens demonstrated the most efficacious antimalarial activity.A bioassay-guided fractionation of these extracts to identify the lead compound is proved to be useful.The results validate the traditional use of the selected plants as antimalarials.

Ethnobotanical database based screening and identification of potential plant species with antiplasmodial activity against chloroquine-sensitive (3D7) strain of Plasmodium falciparum

Objective: To evaluate the antiplasmodial activity of aqueous-methanolic plant extracts of nine plant species selected, based on ethnobotanical data. Methods: Based on ethnobotanical database, the selected plants were tested for their antiplasmodial activity against chloroquine-sensitive (3D7) strain of Plasmodium falciparum. Qualitative tests and high performance thin layer chromatography analysis were carried out to explore the phytocomponents present in the plant extracts. 1,1-diphenyl-2-picrylhydrazyl antioxidant activity was also determined to check the antioxidant activity of the plant extracts. Results: Moringa oleifera (IC

Antiplasmodial activity of silver nanoparticles: A novel green synthesis approach

Objective: To synthesize silver nanoparticles using silver nitrate by a green technique which involves different compositions of aqueous leaf extracts of Azadirachta indica (neem) and Ocimum sanctum (tulsi). Methods: Their shape and size were determined using transmission electron microscopy and UV-visible spectroscopy. Their antiplasmodial activity was studied using the malarial parasite strain (Plasmodium falciparum, 3D7). The parasite strain (3D7) was collected and revived in vitro using Trager and Jensen method in RPMI 1640 medium for 7-8 cycles. Half maximal effective concentration values were calculated by nonlinear regression analysis. Results: Transmission electron microscopy results confirmed the formation of silver nanoparticles with size ranging from 4.74-39.32 nm and their size differs by varying the concentrations from 20% to 100% of neem extract in neem and tulsi extracts. It was observed that samples B and C showed half maximum effective concentration of about 0.3 μ M. Conclusions: It can be easily established that the aqueous leaf extracts of neem and tulsi in combination can be a good source for synthesis of silver nanoparticles with small size possessing appreciable antiplasmodial activity.

Antiplasmodial and Cytotoxic Activities of Toad Venoms from Southern Amazon, Brazil

The drug-resistance of malaria parasites is the main problem in the disease control. The huge Brazilian biodiversity promotes the search for new compounds, where the animal kingdom is proving to be a promising source of bioactive compounds. The main objective of this study was to evaluate the antiplasmodial and cytotoxic activity of the compounds obtained from the toad venoms of Brazilian Amazon. Toad venoms were collected from the secretion of Rhinella marina and Rhaebo guttatus in Mato Grosso State, Brazil. The powder was extracted at room temperature, yielding 2 extracts (RG and RM) and a substance ('1') identified as a bufadienolide, named telocinobufagin. Growth inhibition, intraerythrocytic development, and parasite morphology were evaluated in culture by microscopic observations of Giemsa-stained thin blood films. Cytotoxicity was determined against HepG2 and BGM cells by MTT and neutral red assays. The 2 extracts and the pure substance ('1') tested were active against chloroquine-resistant Plasmodium falciparum strain, demonstrating lower IC₅₀ values. In cytotoxic tests, the 2 extracts and substance '1' showed pronounced lethal effects on chloroquine-resistant P. faciparum strain and low cytotoxic effect, highlighting toad parotoid gland secretions as a promising source of novel lead antiplasmodial compounds.

In vitro antiplasmodial and antioxidant activities of bisbenzylisoquinoline alkaloids from Alseodaphne corneri Kosterm

OBJECTIVE@#To study antiplasmodial and antioxidant activities of the isolation of alkaloids from the active dichloromethane extract of Alseodaphne corneri.@*METHODS@#Phytochemical studies of the crude extract led to the isolation of six alkaloids using recycle high performance liquid chromatography and preparative thin layer chromatography. The antiplasmodial activity of the isolated compounds was evaluated using the histidine-rich protein II assay. The isolated alkaloids were also tested for their antioxidant activity using three different assays; DPPH, ferric reducing ability of plasma and metal chelating assays.@*RESULTS@#Malaria infection caused the formation of free radicals which subsequently led to oxidative stress and apoptosis. The antioxidant properties of the alkaloids under investigation revealed that in addition to the antiplasmodial activity, the alkaloids could also prevent oxidative stress. (+)-laurotetanine and (+)-norstephasubine exhibited strong antiplasmodial activities with IC50 values of 0.189 and 0.116 μM, respectively.@*CONCLUSIONS@#Interestingly, the two most potent compounds that exhibit antiplasmodial activity also exhibit good antioxidant activities. The crude dichloromethane extract and the isolated compounds exert substantial antiplasmodial and antioxidative activities which in turn suppress oxidative stress and cause less damage to the host.