title: Filaricidal activities on Onchocerca ochengi and Loa loa, toxicity and phytochemical screening of extracts of Tragia benthami and Piper umbellatum.
abstract: 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 (IC50s: 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 IC50s 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.
authors: ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon. fidelis.cho@ubuea.cm.
authors: Fidelis
authors: F
authors: Cho-Ngwa
authors: ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.
authors: Elvis
authors: E
authors: Monya
authors: ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.
authors: Boris K
authors: BK
authors: Azantsa
authors: ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.
authors: Faustin Pascal T
authors: FP
authors: Manfo
authors: Department of Chemistry, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.
authors: Smith B
authors: SB
authors: Babiaka
authors: Department of Chemistry, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.
authors: James A
authors: JA
authors: Mbah
authors: ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.|Department of Biomedical Sciences, Faculty of Health Sciences, University of Bamenda, P.O. Box 39, Bambili, Cameroon.
authors: Moses
authors: M
authors: Samje
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D019665:Euphorbiaceae / Q000737:chemistry*; D005369:Filaricides / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D000882:Haplorhini; D008117:Loa / Q000187:drug effects*; D009854:Onchocerca / Q000187:drug effects*; D031701:Piper / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity
chemical_list: D005369:Filaricides; D010936:Plant Extracts
keywords: Loa loa; Onchocerciasis; Piper umbellatum; Tragia benthami