Evaluation of macrofilaricidal and microfilaricidal activities against Onchocerca ochengi and cytotoxicity of some synthesized azo compounds containing thiophene backbone

• Published in: Parasitology research (1987) Vol. 120; no. 6; pp. 2087 - 2094
• Main Authors: Tsemeugne, Joseph, Shinyuy, Lahngong M., Djeukoua, Sorel K. D., Sopbue, Emmanuel F., Ngemenya, Moses N.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-06-2021; Springer; Springer Nature B.V
• Subjects: Analysis; Anthelmintic agents; Azo compounds; Biomedical and Life Sciences; Biomedicine; Cytotoxicity; Epithelial cells; Helminthology - Original Paper; Immunology; Ivermectin; Kidneys; Medical Microbiology; Microbiology; Onchocerca; Onchocerciasis; Parasite resistance; Thiophene; Cameroon; Macrofilaricidal; Cytotoxicity; Anthelmintic; Onchocerciasis; Thienylazoaryls; Microfilaricidal
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-021-07162-3

Control and treatment of onchocerciasis, a devastating tropical filarial disease caused by
Onchocerca volvulus
, rely solely on the community directed treatment with ivermectin. However, ivermectin is only microfilaricidal with evidence of resistance of the parasite among other limitations, which necessitate the search for new efficacious and safe filaricides. Ten synthetic thienylazoryl dyes were screened in vitro against adult and microfilariae worm stages of
Onchocerca ochengi
based on worm motility and MTT formazan assay. Cytotoxicity of active compounds was assessed on monkey kidney epithelial cells (LLC-MK2) using the MTT formazan assay. Seven (7) compounds showed both macrofilaricidal activity against adult male worms and microfilaricidal activity among which three
4a
,
4c
and
4e
recorded the highest activity (IC
50
= 4.2 to 8.8μM) against adult male worms, comparable to some standard anthelmintics. Five compounds showed rapid activity against microfilariae with 100% inhibition after 24-h incubation. The active compounds were nontoxic on monkey kidney cells (CC
50
> 4μg/mL), but their selectivity index values were relatively low (≤ 3). The thienylazoaryls with both macrofilaricidal and microfilaricidal activities may yield molecules which could be used for eradication of onchocerciasis following further medicinal chemistry modification of their structures to enhance their selectivity.