Filaricidal activities on Onchocerca ochengi and Loa loa, toxicity and phytochemical screening of extracts of Tragia benthami and Piper umbellatum (original) (raw)
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BMC Complementary and Alternative Medicine, 2014
Background: Onchocerciasis caused by Onchocerca volvulus is the world's second leading infectious cause of blindness. There is currently no cure for the disease. Ivermectin, the current drug of choice is only microfilaricidal and suboptimal response to it is increasingly being reported. Thus, in contributing to the search for a cure, crude extracts and chromatographic fractions of Craterispermum laurinum and Morinda lucida were screened in vitro, against the bovine and most popular model of the parasite, Onchocerca ochengi. Methods: Extracted parasites were cultured in RPMI-1640 based media for 05 days in the presence of control drugs, test drugs or drug diluents only. Microfilarial motility was scored using microscopy while adult worm viability was determined biochemically by MTT/formazan colorimetry. Cytotoxicity and acute toxicity of active fractions were tested on monkey kidney epithelial cells (LLCMK2) and in Balb/c mice, respectively.
BMC Complementary and Alternative Medicine, 2010
Background: The current treatment of onchocerciasis relies on the use of ivermectin which is only microfilaricidal and for which resistant parasite strains of veterinary importance are increasingly being detected. In the search for novel filaricides and alternative medicines, we investigated the selective activity of crude extracts of Margaritaria discoidea and Homalium africanum on Onchocerca ochengi, a model parasite for O. volvulus. These plants are used to treat the disease in North West Cameroon. Methods: Sixteen crude extracts were prepared from various parts of M. discoidea and H. africanum using different organic solvents. The filaricidal activities were determined in vitro. Cytotoxicity of the active extracts was assessed on monkey kidney epithelial cells in vitro and the selectivity indices (SI) of the extracts determined. Acute toxicity of the promising extracts was investigated in mice. Results: Four out of the 16 extracts showed microfilaricidal activity based on motility reduction, whereas, none showed macrofilaricidal activity based on the MTT/formazan assay. The methylene chloride extract of H. africanum leaves (HLC) recorded the lowest IC 50 of 31.25 μg/mL and an IC 100 of 62.5 μg/mL. The SI for the active extracts ranged from 0.5-2.63. No form of acute toxicity was observed in mice. Phytochemical analysis revealed the presence of anthraquinones, sterols and terpenoids in the promising extracts. Conclusions: The non-polar extracts of M. discoidea and H. africanum are potential sources of new microfilaricidal lead compounds, and the results support their use in traditional medicine.
PLoS neglected tropical diseases, 2018
Ivermectin is the only drug currently recommended for the treatment of onchocerciasis, the second leading infectious cause of blindness in the world. This drug kills only the first stage larvae-microfilariae (mf) of Onchocerca volvulus and is to be used cautiously in areas where Loa loa is prevalent because of severe adverse events observed with coinfected patients. This study investigated the anti-filarial activities of two Cameroonian medicinal plants, Lantana camara and Tamarindus indica locally used to treat onchocerciasis. Twelve (12) extracts were prepared and tested in vitro on the bovine model parasite, O. ochengi as well as L. loa mf. Both mf and adult male worm viabilities were assessed by motility scoring, while adult female worm viability was determined biochemically by standard MTT/formazan colorimetry. Cytotoxicity and acute toxicity were determined respectively, in monkey kidney epithelial cells and in BALB/c mice. Pure compounds were isolated by LC/MS using a bio-ass...
BMC Complementary and Alternative Medicine
Background: Onchocerciasis is one of the tropical neglected diseases (NTDs) caused by the nematode Onchocerca volvulus. Control strategies currently in use rely on mass administration of ivermectin, which has marked activity against microfilariae. Furthermore, the development of resistance to ivermectin was observed. Since vaccine and safe macrofilaricidal treatment against onchocerciasis are still lacking, there is an urgent need to discover novel drugs. This study was undertaken to investigate the anthelmintic activity of Lophira lanceolata on the cattle parasite Onchocerca ochengi and the anthelmintic drug resistant strains of the free living nematode Caenorhabditis elegans and to determine the phytochemical profiles of the extracts and fractions of the plants. Methods: Plant was extracted in ethanol or methanol-methylene chloride. O. ochengi, C. elegans wild-type and C. elegans drug resistant strains were cultured in RPMI-1640 and NGM-agar respectively. Drugs diluted in dimethylsulphoxide/RPMI or M9-Buffer were added in assays and monitored at 48 h and 72 h. Worm viability was determined by using the MTT/formazan colorimetric method. Polyphenol, tannin and flavonoid contents were determined by dosage of gallic acid and rutin. Acute oral toxicity was evaluated using Swiss albino mice. Results: Ethanolic and methanolic-methylene chloride extracts killed O. ochengi with LC 50 values of 9.76, 8.05, 6. 39 μg/mL and 9.45, 7.95, 6.39 μg/mL respectively for leaves, trunk bark and root bark after 72 h. The lowest concentrations required to kill 50% of the wild-type of C. elegans were 1200 and 1890 μg/mL with ethanolic crude extract, 1000 and 2030 μg/mL with MeOH-CH 2 Cl 2 for root bark and trunk bark of L. lanceolata, respectively after 72 h. Leave extracts of L. lanceolata are lethal to albendazole and ivermectin resistant strains of C. elegans after 72 h. Methanol/methylene chloride extracted more metabolites. Additionally, extracts could be considered relatively safe. Conclusion: Ethanolic and methanolic-methylene chloride crude extracts and fractions of L. lanceolata showed in vitro anthelmintic activity. The extracts and fractions contained polyphenols, tannins, flavonoids and saponins. The mechanism of action of this plant could be different from that of albendazole and ivermectin. These results confirm the use of L. lanceolata by traditional healers for the treatment of worm infections.
Tropical Journal of Natural Product Research, 2018
The present study is a survey of medicinal plants used to manage onchocerciasis in Ibarapa Local Government Area of Oyo State, Nigeria. Semi structured questionnaires targeted at traditional medical practitioners (TMP), traditional birth attendants, herb sellers, herbalists and elders in the communities was used to collect relevant information. Data collected were analyzed by the use of mention index (UMI) and frequency. Literature review was used to judge the usefulness of the recommended plants in onchocerciasis. There were one hundred and thirty-three respondents comprising of TMP (12.8%), herb sellers (26.3%), herbalist (31.6%) and elders in the communities who do not practice any of the listed professions (29.3%). Plants used for treatment of onchocerciasis infection cut across the local government area. The survey revealed eighty plants from 35 families. Xylopia aethiopica (UMI 0.504) was the most frequently used plant. This was followed by Tetrapleura tetraptera, Allium ascalonicum, Parkia clappertoniana, Securidaca longepedunculata, Plumbago zeylanica and Parquetina nigrescens. The most used plant part was the leaf (34%) followed by the bark (27%) while decoction and infusion were the methods of preparation mostly used. The study showed that the knowledge of plants used in treatment of onchocerciasis disease exist in many communities in Ibarapa Local Government Area. There are 56 plants reportedly identified for use against onchocerciasis as shown in this study with leguminoseae (13.75%) being the most dominant family. The plants included have significant UMI which should prompt further scientific studies to identify the active constituents and determine their toxicological profiles.
Background: Onchocerciasis transmitted by Onchocerca volvulus is the second major cause of blindness in the world and it impacts negatively on the socioeconomic development of the communities affected. Currently, ivermectin, a microfilaricidal drug is the only drug recommended for treating this disease. There have been speculations, of late, concerning O. volvulus resistance to ivermectin. Owing to this, it has become imperative to search for new drugs. Worldwide , ethnomedicines including extracts of Euphorbia hirta and Rauvolfia vomitoria are used for treating various diseases, both infectious and non-infectious. Method: In this study extracts of the two plants were evaluated in vitro in order to determine their effect against O. volvulus microfilariae. The toxicity of the E. hirta extracts on monkey kidney cell (LLCMK2) lines was also determined. Results: The investigations showed that extracts of both plants immobilised microfilariae at different levels in vitro and, therefore, possess antifilarial properties. It was found that all the E. hirta extracts with the exception of the hexane extracts were more effective than those of R. vomitoria. Among the extracts of E. hirta the ethyl acetate fraction was most effective, and comparable to that of dimethanesulphonate salt but higher than that of Melarsoprol (Mel B). However, the crude ethanolic extract of E. hirta was found to be the least toxic to the LLCMK2 compared to the fractionated forms. Conclusions: Extracts from both plants possess antifilarial properties; however, the crude extract of E. hirta was found to be least toxic to LLCMK2.
Natural Anti-onchocercals from Cameroon Medicinal Plants
Onchocerciasis or river blindness, an infectious parasitic disease, is caused by the nematode, Onchocderca volvulus. It is one of the ten tropical neglected diseases and millions of people worldwide are exposed to it, particularly in sub-Sahara Africa. The treatment of the disease currently depends on mass administration of ivermectin (merctizan), a synthetic drug, which is only effective against microfilariae. In Cameroon, like elsewhere, a number of medicinal plants have shown anti-onchocercal activity and in this minireview, the phytochemistry and pharmacology of some of these plants are highlighted.
Journal of Medicinal Plants Research, 2015
This study was carried out to isolate active ingredients from Voacanga africana Stapf (Apocynaceae) used as herbal medicine in Cameroon, and also to assess the efficacy of the compounds on Onchocerca ochengi and Loa loa worms. The compounds were isolated using solvent partitioning, column chromatography and fractional crystallization. The O. ochengi worms were isolated from cow skin while Loa loa was isolated from humans. Filaricidal activity was determined based on motility for adult male worms and microfilariae (Mfs), while adult female worm viability was assessed biochemically by the dimethylthiazol (MTT)/formazan assay. Cytotoxicity was assessed using monkey kidney epithelial cells. Auranofin was used as the positive control drug. Two compounds, voacangine (compound 1) and voacamine (compound 2) were isolated from the stem bark of Voacanga africana. Both compounds were found to inhibit the motility of both the microfilariae (Mfs) and adult male worms of O. ochengi in a concentration-dependent manner, but were only moderately active on the adult female worms upon biochemical assessment at 30 µM drug concentration. The IC 50 s for voacangine were 5.49 µM for Mfs and 9.07 µM for adult male worms; while for voacamine the values were 2.49 µM for Mfs and 3.45 µM for adult males. At 10 µM, voacamine showed 100% inhibition of Loa loa Mfs motility after 24 h. This is the first report of the anti-Onchocerca activity of voacangine (compound 1) and voacamine (compound 2) as well as activity of voacamine (compound 2) on L. loa. The results of this study support the traditional use of V. africana in the treatment of human onchocerciasis.
Natural Products and Bioprospecting, 2014
The aims of this investigation were to isolate active ingredients from the roots/rhizomes of Cyperus articulatus used as herbal medicine in Cameroon for the treatment of human onchocerciasis and to assess the efficacy of the metabolites on the Onchocerca worm. The antifilarial activity was evaluated in vitro on microfilariae (Mfs) and adult worms of the bovine derived Onchocerca ochengi, a close relative of Onchocerca volvulus. Cytotoxicity was assessed in vitro on monkey kidney epithelial cells. The structures of the active compounds were determined using spectroscopic methods and their drug-likeness evaluated using Lipinski parameters. Two secondary metabolites, AMJ1 [containing mustakone (1) as the major component] and linoleic acid or (9Z,12Z)-octadeca-9,12-dienoic acid (2) were isolated. Both compounds were found to kill both the microfilariae and adult worms of O. ochengi in a dose dependent manner. The IC 50 s for AMJ1 were 15.7 lg/mL for Mfs, 17.4 lg/mL for adult males and 21.9 lg/mL for adult female worms while for linoleic acid the values were, 15.7 lg/mL for Mfs, 31.0 lg/mL for adult males and 44.2 lg/mL for adult females. The present report provides the first ever evidence of the anti-Onchocerca efficacy of AMJ1 and linoleic acid. Thus, these secondary metabolites may provide a lead for design and development of new antifilarial agents.
In vivo Toxicity Study and Antifilarial Activity of Four Plants from Nord-Cameroon
European Journal of Medicinal Plants, 2017
Aims: The objective of this work was to seek an alternative drug against onchocerciasis based on medicinal plants. Study Design: Ethanolic extracts of stem barks, leaves and roots of Detarium microcarpum, Guiera senegalensis, Trichilia emetica and Vitellaria paradoxa were evaluated in vitro against the cattle filarial parasite Onchocerca ochengi, a model organism similar to Onchocerca volvulus.