In vivo Toxicity Study and Antifilarial Activity of Four Plants from Nord-Cameroon (original) (raw)
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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.
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.
BMC Complementary and Alternative Medicine, 2016
Background: Onchocerciasis is the world's second leading infectious cause of blindness. Its control is currently hampered by the lack of a macrofilaricidal drug and by severe adverse events observed when the lone recommended microfilaricide, ivermectin is administered to individuals co-infected with Loa loa. Therefore, there is the need for a safe and effective macrofilaricidal drug that will be able to cure the infection and break transmission cycles, or at least, an alternative microfilaricide that does not kill L. loa microfilariae (mf). Methods: Fourteen extracts from two medicinal plants, Tragia benthami and Piper umbellatum were screened in vitro against Onchocerca ochengi parasite and L. loa mf. Activities of extracts on male worms and microfilariae were assessed by motility reduction, while MTT/Formazan assay was used to assess biochemically the death of female worms. Cytotoxicity and acute toxicity of active extracts were tested on monkey kidney cells and Balb/c mice, respectively. Results: At 500 μg/mL, all extracts showed 100 % activity on Onchocerca ochengi males and microfilariae, while 9 showed 100 % activity on female worms. The methylene chloride extract of Piper umbellatum leaves was the most active on adult male and female worms (IC 50 s: 16.63 μg/mL and 35.65 μg/mL, respectively). The three most active extracts on Onchocerca ochengi females were also highly active on Loa loa microfilariae, with IC 50 s of 35.12-13. 9 μg/mL. Active extracts were generally more toxic to the worms than to cells and showed no acute toxicity to Balb/c mice. Phytochemical screening revealed the presence of saponins, steroids, tannins and flavanoids in the promising extracts. Conclusions: These results unfold potential sources of novel anti-Onchocerca lead compounds and validate the traditional use of the plants in onchocerciasis treatment.
Ethnobotanical study of plants used against onchocerciasis in the far north region of Cameroon
Journal of Medicinal Plants Research, 2020
Despite the multitude of studies which have shown the use of medicinal plants in the management of parasitic diseases, little data was available on the plants used against onchocerciasis. Ethnobotanical surveys were carried out among traditional healers in the Far North region of Cameroon. Studies were conducted from July 2017 to May 2018 through direct interviews using a semi-structured questionnaire taking into consideration the socio-demographic characteristics of the respondents as well as their knowledge in the art of onchocerciasis and parasitic infections treatment using plant recipes. A total of one hundred people were interviewed in villages found in the Far North region of Cameroon: 43 were females and 57 males, among which, 71 were recognized as traditional healers. Adults were the most represented (71 respondents). The study identified 96 plant species belonging to 49 genera divided into 29 families among which the most represented was the Fabaceae (20 quotes). The most ...
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.
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.
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.
Journal of Pharmacognosy and Phytochemistry
Among the many plants that have yet to be studied and that populate the rich African flora, an invaluable reservoir of bioactive molecules, is Detarium microcarpum, a tree of the Fabaceae family 8 to 12 m high, a species of the wooded savannahs and open forests of the Sudano-Sahelian zone of the African continent. This plant has long been used in traditional medicine to treat stomach aches, menstrual pain, dysenteric diarrhoea, dermatitis, meningitis, gonorrhoea, rheumatism, tuberculosis, smallpox, bilharzia, itching, gastric ulcers and diabetes. Phytochemical work on this plant reported about 40 secondary metabolites isolated mainly from extracts of trunk bark, leaves and fruits. The isolated compounds included carbohydrates, coumarins, flavonoids, sterols and terpenoids and other compounds. The crude extracts of the different organs and the compounds isolated from them showed a wide spectrum of pharmacological activities including antiviral, antioxidant, antibacterial, antiparasitic, antiinflammatory, antidiabetic, anthelmintic, larvicidal and molluscicidal activities. The aim of this review is to provide an update on the existing knowledge on the different organs of Detarium microcarpum.
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...