In vitro antiplasmodial activity of crude extracts from Togolese medicinal plants

ObjectiveTo investigate the antimalarial effect of a few plants in Togo folk medicine.MethodsAfter ethnobotanical survey, Opilia celtidifolia, Pavetta corymbosa (P. corymbosa) and Tamarindus indica (T. indica) were selected for screening. In vitro antimalarial tests were performed on crude extracts against fresh clinical isolates of Plasmodium falciparum using the semi microtest.ResultsDifferent IC₅₀ values of the extracts ranged from 2.042 to 100.000 μg/mL. According to the results, the methanol extract of aerial part of P. corymbosa followed by aqueous extract of fruit of T. indica were the most active (IC₅₀ of 2.042 and 4.786 μg/mL, respectively). Qualitative test revealed the presence of alkaloids in the leaves of P. corymbosa that may be responsible for the activity of the plant.ConclusionsOur study provides scientific evidence for usage of plant in the folk medicine, and further studies are needed for identification and purification of the active principles.     

In vitro antiplasmodial activity of Central American medicinal plants

The in vitro antiplasmodial activities of 14 plant species traditionally used in Central America for the treatment of malaria or fever were evaluated. Lipophilic extracts of Piper hispidum, Siparuna andina, S. pauciflora, S. tonduziana, and Xylopia cf. frutescens, proved to be active against both a chloroquine-sensitive and a resistant strain of Plasmodium falciparum. IC50 values ranged between 3.0 microg/ml and 21.9 microg/ml; however, moderate cytotoxicity of active extracts was observed. Bioactivity-guided fractionation of Piper hispidum yielded 2',4, 6'-trihydroxy-4'-methoxydihydrochalcone (asebogenin) as an active compound.     

In vitro antitrypanosomal activity,antioxidant property and phytochemical constituents of aqueous extracts of nine Nigerian medicinal plants

ObjectiveTo study the in vitro antitrypanosomal activity, antioxidant property and phytochemical constituents of aqueous extracts of nine Nigerian medicinal plants.MethodsIn vitro antitrypanosomal activity test was carried out on aqueous extracts of dried leaves of Acacia albida (A. albida), Artemisia absinthium, Bryophyllum pinnatum, Gongronema latifolium, Holarrhena floribunda, Leptadenia hastata, Pericopsis laxiflora (P. laxiflora) and dried stem barks of A. albida and P. laxiflora. The phytochemical constituents and composition of the extracts and the in vitro antioxidant activity of the extracts were subsequently measured using the α,α-diphenyl-β-picryl-hydrazyl (DPPH) radical scavenging assay, Ferric reducing antioxidant power (FRAP) assay, thiobarbituric acid (TBA) activity assay and H₂O₂ radical scavenging activity assay.ResultsFrom the study, it was discovered that the stem bark extracts of A. albida and P. laxiflora were most active against both Trypanosoma evansi and Trypanosoma congolense. There was complete cessation of motility in both trypanosomes within 5 min at 40 mg/mL of the stem bark extract of A. albida and complete cessation of motility within 25 min and 40 min at 40 mg/mL with P. laxiflora stem bark extract for Trypanosoma congolense and Trypanosoma evansi, respectively. Quantitative analysis of the phytochemical constituents of the aqueous extracts of the plant parts such as alkaloids, saponins, flavonoids and phenols revealed that the stem barks of A. albida, P. laxiflora and leaves of Leptadenia hastata contained relatively high amount of all the phytochemicals quantified. The stem bark extracts of A. albida, P. laxiflora and leaves of Gongronema latifolium possess more scavenging capacity when compared to other extracts in relation to vitamin C, the reference antioxidant.ConclusionsThis study provides scientific evidence for the use of A. albida, and P. laxiflora for the treatment of trypanosomosis and diseases associated with oxidative stress.     

In vitro screening of traditionally used medicinal plants in China against enteroviruses

AIM: To search for new antiviral agents from traditional Chinese medicine, specifically anti-enterovirosuses agents. METHODS: The aqueous extracts (AE) of more than 100 traditionally used medicinal plants in China were evaluated for their in vitro anti-Coxsackie virus B3 activities with a MTT-based colorimetric assay. RESULTS: The test for AE of 16 plants exhibited anti-Coxsackie virus B3 activities at different magnitudes of potency. They can inhibit three steps (inactivation, adsorption and replication) during the infection. Among the 16 plants, Sargentodoxa cuneata (Oliv.) Rehd. et Wils., Sophora tonkinensis Gapnep., Paeonia veitchii Lynch, Spatholobus suberectus Dunn. and Cyrtomium fortunei J. sm. also have activity against other enterovirus, including Coxsackie virus B5, Polio virus I, Echo virus 9 and Echo virus 29. Cell cytotoxic assay demonstrated that all tested AE had CC50 values higher than their EC50 values. CONCLUSION: The sixteen traditionally used medicinal plants in China possessed antiviral activity, and some of them merit further investigations.     

In vitro antimalarial activity and cytotoxicity of some selected cuban medicinal plants

Terrestrial plants have been demonstrated to be sources of antimalarial compounds. In Cuba, little is known about antimalarial potentials of plant species used as medicinals. For that reason, we evaluated the antimalarial activity of 14 plant species used in Cuba as antimalarial, antipyretic and/or antiparasitic. Hydroalcoholic extracts were prepared and tested in vitro for the antimalarial activity against Plasmodium falciparum Ghana strain and over human cell line MRC-5 to determine cytotoxicity. Parasite multiplication was determined microscopically by the direct count of Giemsa stained parasites. A colorimetric assay was used to quantify cytotoxicity. Nine extracts showed IC50 values lower than 100 μg/mL against P. falciparum, four extracts were classified as marginally active (SI < 4), one as partially active (Parthenium hysterophorus) exhibiting SI equal to 6.2 and two extracts as active (Bambusa vulgaris and Punica granatum), showing SI > 10. B. vulgaris showed the most potent and specific antiplasmodial action (IC50 = 4.7 μg/mL, SI = 28.9). Phytochemical characterization of active extracts confirmed the presence of triterpenoids in B. vulgaris and polar compounds with phenol free groups and fluorescent metabolites in both extracts as major phytocompounds, by thin layer chromatography. In conclusion, antimalarial use of B. vulgaris and P. hysterophorus was validated. B. vulgaris and P. granatum extracts were selected for follow-up because of their strong antimalarial activity.     

Bioprospecting medicinal plants for antioxidant components

ObjectiveTo evaluate antioxidant activities of seven medicinal plant species and their fractions, and to identify their phenolic compounds.MethodsTwo extractions were processed and further fractionated by column chromatography to evaluate the concentration that inhibit 50% of 2,2′-azinobis (3-ethylbenzothiazoline-6-suslfonic acid, 1,1-diphenyl-2-picryl-hydrazyl radicals, and their ferric reducing antioxidant power. The identification of the fractions of phenolic compounds was done by ultra performance liquid chromatography.ResultsThe aqueous-acetone extracts of Feretia apodanthera and Ozoroa insignis exhibited the highest antioxidant potentials comparable to those of the standard quercetin. Their subsequently silica gel column fractionation showed three most active fractions from which the major constituents quercetin, myricetin, kampferol, rutin and isoquercetin were identified.ConclusionsThese plant species have potent antioxidant profiles and polyphenol compounds that may help to manage with radical related disease and aging.     

In vitro antiplasmodial activity of ethanolic extracts of South Indian medicinal plants against Plasmodium falciparum

ObjectiveTo explore the antiplasmodial potential ofCatharanthus roseus L (C. roseus), Coccinea grandis (C. grandis), Thevetia peruviana (T. peruviana), Prosopis juliflora (P. juliflora), Acacia nilotica (A. nilotica), Azadirachta indica (A. indica) (Abr. Juss) and Morinda pubescens (M. pubescens).MethodsThe C. roseus L, C. grandis, T. peruviana, P. juliflora, A. nilotica, A. indica (Abr. Juss) and M. pubescens were collected from Ramanathapuram District, Tamil Nadu, India and the extraction was carried out in ethanol. The filter sterilized extracts (100, 50, 25, 12.5, 6.25 and 3.125 μg/mL) were tested for antiplasmodial activity against Plasmodium falciparum. The phytochemical constituents in the potential extracts were also detected.ResultsOf the selected plants species, the bark extract of A. indica (Abr. Juss) showed excellent antiplasmodial activity (IC₅₀ 29.77 μg/mL) followed by leaf extract of A. indica (Abr. Juss) (IC₅₀47.20 μg/mL) and leaf extract of C. roseus L (IC₅₀49.63 μg/mL). The leaf, bark and flower extracts of P. juliflora showed IC₅₀values of more than 100 μg/mL. Statistical analysis reveals significant antiplasmodial activity (P<0.01) between the concentrations and time of exposure. Additionally, no chemical injury was found in the erythrocytes incubated with the ethanolic extract of all the tested plants. The in vitro antiplasmodial activity might be due to the presence of alkaloids, glycosides, carbohydrates, flavonoids, phenols, saponins, triterpenoids, proteins and tannins in the ethanolic extracts of the tested plants.ConclusionsThe ethanolic bark extracts of A. indica (Abr. Juss) possess lead compounds for the development of antiplasmodial drugs.     

In vitro screening for antiplasmodial activity of isoquinoline alkaloids from Brazilian plant species

In the search for new antimalarial agents, nine Brazilian plant species were selected, from the Annonaceae (6), Menispermaceae (2) and Siparunaceae (1) families naturally occurring at the cerrado and Atlantic rainforest regions, in order to investigate their in vitro antiplasmodial activity. The ethanol and the alkaloid extracts were tested against K1, chloroquine-resistant, and Palo Alto, chloroquine-sensitive, strains of Plasmodium falciparum. The majority of the alkaloid extracts were more active than the ethanol ones, with IC(50) ranging 0.3-8.2 microg/mL. The crude Guatteria australis alkaloids were the most active against K1 with an IC(50) = 0.3 microg/mL. The most promising total alkaloid fractions for further bioguided isolation are those with the IC(50) < or = 5 microg/mL: G. australis, Cissampelos ovalifolia and Duguetia lanceolata.     

Unlocking the in vitro anti-Trypanosoma cruzi activity of halophyte plants from the southern Portugal

Objective:To evaluate the in vitro anti-Trypanosoma cruzi(T.cruzi) activity of organic extracts prepared from halophyte species collected in the southern coast of Portugal(Algarve),and chemically characterize the most active samples.Methods:Acetone,dichloromethane and methanol extracts were prepared from 31 halophyte species and tested in vitro against trypomastigotes and intracellular amastigotes of the Tulahuen strain of T.cruzi.The most active extract was fractionated by preparative HPLC-DAD,affording 11 fractions.The most selective fraction was fully characterized by ~1H-NMR.Results:From 94 samples tested,one was active,namely the root dichloromethane extract of Juncus acutus(IC_(50) 20 μg/mL).This extract was fractionated by HPLC,affording 11 fractions,one of them containing only a pure compound(juncunol),and tested for anti-parasitic activity.Fraction 8(IC_(50) = 4.1 μg/mL) was the most active,and was further characterized by ~1H-NMR.The major compounds were phenanthrenes,9,10-dihydrophenanthrenes and benzocoumarins.Conclusion:Our results suggest that the compounds identified in fraction 8 are likely responsible for the observed anti parasitic activity.Further research is in progress aiming to isolate and identify the specific active molecules.To the best of our knowledge,this is the first report on the in vitro anti T.cruzi activity of halophyte species.     

In vitro total phenolics, flavonoids contents and antioxidant activity of essential oil, various organic extracts from the leaves of tropical medicinal plant Tetrastigma from Sabah

ObjectiveTo detect the in vitro total phenolics, flavonoids contents and antioxidant activity of essential oil, various organic extracts from the leaves of tropical medicinal plant Tetrastigma from Sabah.MethodsThe dry powder leaves of Tetrastigma were extracted with different organic solvent such as hexane, ethyl acetate, chloroform, butanol and aqueous methanol. The total phenolic and total flavonoids contents of the essential oil and various organic extracts such as hexane, ethyl acetate, chloroform, butanol and aqueous ethanol were determined by Folin - Ciocalteu method and the assayed antioxidant activity was determined in vitro models such as antioxidant capacity by radical scavenging activity using α, α-diphenyl- β-picrylhydrazyl (DPPH) method.ResultsThe total phenolic contents of the essential oil and different extracts as gallic acid equivalents were found to be highest in methanol extract (386.22 mg/g) followed by ethyl acetate (190.89 mg/g), chloroform (175.89 mg/g), hexane (173.44 mg/g), and butanol extract (131.72 mg/g) and the phenolic contents not detected in essential oil. The antioxidant capacity of the essential oil and different extracts as ascorbic acid standard was in the order of methanol extract > ethyl acetate extract >chloroform> butanol > hexane extract also the antioxidant activity was not detected in essential oil.ConclusionsThe findings show that the extent of antioxidant activity of the essential oil and all extracts are in accordance with the amount of phenolics present in that extract. Leaves of Tetrastigma being rich in phenolics may provide a good source of antioxidant.     

In vitro screening assay for teratogens using growth inhibition of human embryonic cells.

We have tested 35 teratogenic and 20 nonteratogenic chemicals or drugs in a short-term, in vitro assay that identifies teratogens by their ability to inhibit growth of an established line of human embryonic palatal mesenchymal cells. Only those chemicals that exhibited a dose-dependent inhibition of growth at concentrations less than 1 mM were classified as inhibitory. An Aroclor-induced rat liver S-9 system was effective in metabolizing cyclophosphamide to its teratogenic form in culture. We suggest that this assay, along with the complementary tumor cell-attachment assay of Braun et al. [Braun, A. G., Emerson, D. J. & Nichinson, B. B. (1979) Nature (London) 282, 507-509] may be useful as a short-term in vitro battery for assessment of the teratogenic potential in environmental agents and to prioritize those chemicals which merit further testing in vivo.     

A pilot study of antioxidant potential of endophytic fungi from some Sudanese medicinal plants

Objective: To evaluate the total phenolic content and total antioxidant capacity of ethyl acetate extracts of 21 endophytic fungi isolated from five Sudanese medicinal plants: Calotropis procera, Catharanthus roseus, Euphorbia prostrate, Vernonia amygdalina and Trigonella foenumgraecum. Methods: Crude extracts of endophytic fungi and their host plants were tested by classical Folin-Ciocalteu colorimetric method to determine the total phenolic content, also total antioxidant capacity was estimated using 1,1-diphenyl-2-picrylhydrazyl free radical scavenging in vitro method. Results: Among the endophytes, endophytic fungus Aspergillus sp. from Trigonella foenum-graecum seeds demonstrated the highest both total phenolic content in term of gallic acid equivalent(GAE) [(89.9±7.1 mg GAE/g)] and antioxidant activity for 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay [IC50:(18.0±0.1 μg/m L)]. A high positive linear correlation(R2=0.999 1) was found between total antioxidant capacity and total phenolic content of endophytic fungi isolated from Vernonia amygdalina. Conclusions: The present study revealed that some endophytic fungi from the five Sudanese medicinal plants could be a potential source of novel natural antioxidant compounds.     

In vitro antioxidant activity and total phenolic content of endophytic fungi isolated from Eugenia jambolana Lam.

ObjectiveTo elucidate the antioxidant activity and total phenolic content (TPC) of ethyl acetate extracts of endophytic fungi isolated from Eugenia jambolana by three different antioxidant assays.MethodsTwenty one different endophytic fungal extracts were screened for presence of various phytochemicals, TPC and in vitro antioxidant activity. TPC was tested by Folin-Ciocalteau reagent based assay. DPPH free radical scavenging, hydrogen peroxide scavenging and reducing power assays were used to evaluate the antioxidant activity.ResultsAlkaloids, phenols, flavonoids, saponins, and terpenes were the main phytochemicals presents in all 21 endophytes. A significant positive correlation was found between antioxidant activity and TPC in fungal extracts. There is 36% endophytic extracts having high phenolic content exhibited potent antioxidant activity. Chaetomium sp., Aspergillus sp., Aspergillus peyronelii and Aspergillus niger strain showed the highest antioxidant activity ranging from 50% to 80% having 58 mg/g to 60 mg/g GAE total phenolics. Ascorbic acid used as a standard showed 90% reducing potential.ConclusionsThe results reveal that metabolites produced by endophytic fungi isolated from Eugenia jambolana can be a potential source of novel natural antioxidant compounds.     

In vitro porcine brain tubulin assembly inhibition by water extract from a Chinese medicinal herb, Tripterygium hypoglaucum Hutch

AIM:To investigate the effect of Tripterygiumhyp-oglaucum Hutch(THH)on the assembly anddisassembly process of tubulin and its possible mode ofaction.METHODS:In vitro porcine brain tubulin assemblyassay was employed to analyze the inhibitory effects ofTHH at different concentrations(0.05 μg/L,0.07 μg/L,0.09μg/L).Colchicine(0.0025 mmol/L,0.0050 mmol/L,0.0075mmol/L)was used as a positive control.RESULTS:THH could significantly inhibit the assembly ofisolated porcine brain tubulin at all tested concentrations.CONCLUSION:THH is capable of inducing aneuploidyin mammals via tubulin polymerization inhibition pathwayand may pose a genetic risk to human beings.     

Antimicrobial, antiplasmodial, haemolytic and antioxidant activities of crude extracts from three selected Togolese medicinal plants

ObjectiveTo investigate the antioxidant, antimicrobial, antiplasmodial, acute toxicity and haemolytic activities of methanolic extracts of three plants. Phytochemical analysis to determine the phenolic contents was also carried out.MethodsThe 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging, NCCLS broth microdilution and Plasmodium Lactate Dehydrogenase (pLDH) assays were used to determine antioxidant, antimicrobial and antiplasmodial activities, respectively. Haemolysis assay was conducted on A⁺ human red blood cells and acute toxicity on male Swiss albino mice. Phenolics were quantitatively determined using spectrophotometric methods.ResultsThe DPPH assay yielded interesting antioxidant activities of methanolic extract of Parinari curatellifolia (P. curatellifolia) and Entada africana (E. africana) (IC₅₀ were 0.20±0.01 μg/mL and 0.47±0.01 μg/mL, respectively). This activity was highly correlated with phenolic contents of extracts. The antimicrobial tests displayed minimal inhibitory concentrations (MICs) values ranging from 0.90 to 1.80 mg/mL for Serratia marcescens (S. marcescens) the most susceptible bacterial strain. MIC value was 1.20 mg/mL for susceptible fungal strains including Mucor rouxi (M. rouxi), Fusarium oxyporum (F. oxyporum) and Rhizopus nigricans (R. nigricans). pLDH assay showed moderate antiplasmodial activity of Balanites aegyptiaca (B. aegyptiaca) (IC₅₀ = 24.56±3.45 μg/mL), however this extract was highly haemolytic and toxic in mice (LD₅₀ = 625±128 mg/kg).ConclusionsOur results support in part the use of the selected plants in the treatment of microbial infections. In addition the plant showed interesting antioxidant activity that could be useful in the management of oxidative stress.     

Anticancer and antioxidant activities of methanol extracts and fractions of some Cameroonian medicinal plants

ObjectiveTo obtain a scientific basis of the use of plant-derived preparations by many rural people in Cameroon, for their primary health care needs in the treatment of diseases such as cancer.MethodsThe antiproliferative effect of 11 plants methanol crude extracts on four cancer cells using sulforhodamine-B assay and their antioxidant activities using 1-diphenyl-2-picrylhydrazyl radical and nitric oxide radical scavenging ability were investigated. The Ekebergia senegalensis (E. senegalensis) and Protea elliotii (P. elliotii) extracts were selected based on their antioxidant and anticancer activities, and partition in hexane, dichloromethane, ethyl acetate, butanol and methanol was done. Each fraction was submitted to antioxidant and anticancer activities, and the effect of the dichloromethane fraction (the most antiproliferative fraction) on NCI-H460 cell cycle was determined by flow cytometry.ResultsThe most antiproliferative substances were found for the extracts from E. senegalensis, P. elliotii, Terminalia macroptera and Vitellaria paradoxa. Whereas the most antioxidant substances were found for the extracts from Cissus populnea, E. senegalensis, P. elliotii, Terminalia macroptera, Vitellaria paradoxa, and Gardenia aqualla. Dichloromethane fraction of P. elliotii was found to be highly antiproliferative to NCI-H460 cancer cells and showed S phase arrest cell cycle progression. Ethyl acetate n-butanol and methanol fractions showed quite strong antioxidant activity for both E. senegalensis and P. elliotii, as compared to that of gallic acid.ConclusionsOverall, the antiproliferative and antioxidant activities of some of the extracts lend some support to their use in the traditional medicine of Adamawa Region, Cameroon to treat cancer.     

Natural compounds and extracts from Mexican medicinal plants with anti-leishmaniasis activity: An update

Leishmaniasis is considered as an emerging, uncontrolled disease and is endemic in 98 countries. Annually, about 2 million cases of cutaneous and 500000 cases of visceraltype leishmaniasis are recorded and 60000 persons died from the disease. In Mexico,cutaneous leishmaniasis is known as chiclero's ulcer and is reported in 22 states, it is considered as a health problem. For its treatment, pentavalent antimonial drugs are administered. These drugs cause severe side effects, are costly. Drug-resistant cases have been reported and have been developing for over 70 years. One alternative to the drugs that are currently available is to find active molecules in medicinal plants. Dihydrocorynantheine, corynantheine and corynantheidine are active against Leishmania major,while harmane, pleiocarpin, buchtienin, luteolin and quercetin are active against Leishmania donovani. In Mexico, about 20 medicinal plants have been evaluated against Leishmania mexicana, among which the most active are Tridax procumbens, Lonchocarpus xuul and Pentalinon andrieuxii. From these plants, active compounds with IC_(50)≤30 mg/mL or m M have been isolated, such as 3(S)-16,17-didehydrofalcarinol or Oxylipin, cholestra-4,20,24-trien-3-one or pentalinosterol, 24-methylcholest-4-24(28)-dien-3-one, cholest-4-en-3-one, 6,7-dihydroneridie-none, neridienone, cholest-5,20,24-trien-3β-ol, and isocordoin. Today, only pentalinonsterol has been synthesized and assayed in the visceral leishmaniasis experimental model using BALB/c mice infected with Leishmania donovani. Liposome formulation of this compound administered by intravenous route at 2.5 mg/kg showed a significant reduction of parasite load in mouse liver and spleen.     

An In vitro studies on indigenous ayurvedic plants,having hypoglycemic activity

ObjectiveFinding a cure for diseases and infections using herbal medicines are as old as mankind. The present study aimed at investigation of anti-hyperglycemic potential of methanolic extract of some indigenous ayurvedic plants used in Karnataka.Design settingThere are a few explicit studies to confirm invitro hypoglycemic activity. Our work is based on the study of some indigenous plants which show inhibitory effect on glucose oxidase and are in use as hypoglycemic agents in traditional system of medicine.ResultSyzygium cumini, Trigonella foenum graecum seed, Moringa alba leaf, Punica granatum peel, Emblica officinalis and Momordica charantia possessed highest hypoglycemic activity of varying degree. S. cumini and T. foenum had shown the better activity in neutral and basic media than others. Whereas, Alterathera ficoicka leaf, T. foenum and Momordica charantia have shown prominent result in acidic media. The result in three different media revealed that, acidic medium shows less prominent hypoglycemic activity as compared to neutral and basic medium.ConclusionS. cumin, T. foenum seed and M. charantia gave the impression of being prominent candidates for drug targets for diabetes. This may be the first report using invitro approach to prove their antidiabetic properties.     

In vitro screening of carcinogenesis inhibitors acting by inhibition of microsomal polycyclic aromatic hydrocarbon activation

A procedure for in vitro prescreening of carcinogenesis inhibitors acting by the inhibition of the microsomal activation systems is described. It consists of measuring the protection conferred by the investigated chemicals against DNA binding of ultimate carcinogens resulted during G(3H)B[a]P activation. This rapid and reproducible procedure is able to select only carcinogenesis inhibitors which interact with the cytochrome P-450 dependent microsomal enzymes being specific in this respect. The effectiveness of 23 compounds (mainly antioxidants) was tested and the results compared with literary data concerning their activity. The concordance was satisfactory.