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...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 IC50s 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.展开更多
Background:Mass drug administration(MDA)programmes for the control of lymphatic filariasis in Ghana,have been ongoing in some endemic districts for 16 years.The current study aimed to assess factors that govern the su...Background:Mass drug administration(MDA)programmes for the control of lymphatic filariasis in Ghana,have been ongoing in some endemic districts for 16 years.The current study aimed to assess factors that govern the success of MDA programmes for breaking transmission of lymphatic filariasis in Ghana.Methods:The study was undertaken in two"hotspot"districts(Ahanta West and Kassena Nankana West)and two control districts(Mpohor and Bongo)in Ghana.Mosquitoes were collected and identified using morphological and molecular tools.A proportion of the cibarial armatures of each species was examined.Dissections were performed onAnopheles gambiae for filarial worm detection.A questionnaire was administered to obtain information on MDA compliance and vector control activities.Data were compared between districts to determine factors that might explain persistent transmission of lymphatic filariasis.Results:High numbers of mosquitoes were sampled in Ahanta West district compared to Mpohor district(F=16.09,P=0.002).There was no significant difference between the numbers of mosquitoes collected in Kassena Nankana West and Bongo districts(F=2.16,P=0.185).Mansonia species were predominant in Ahanta West district.An.coluzzii mosquitoes were prevalent in all districts.An.melas with infected and infective filarial worms was found only in Ahanta West district.No differences were found in cibarial teeth numbers and shape for mosquito species in the surveyed districts.Reported MDA coverage was high in all districts.The average use of bednet and indoor residual spraying was 82.4 and 66.2%,respectively.There was high compliance in the five preceding MDA rounds in Ahanta West and Kassena Nankana West districts,both considered hotspots of lymphatic filariasis transmission.Conclusions:The study on persistent transmission of lymphatic filariasis in the two areas in Ghana present information that shows the importance of local understanding of factors affecting control and elimination of lymphatic filariasis.Unlike Kassena Nankana West district展开更多
Background:There is compelling evidence that not only do anti-filarials significantly reduce larval forms,but that host immune responses also contribute to the clearance of filarial parasites;however,the underlying me...Background:There is compelling evidence that not only do anti-filarials significantly reduce larval forms,but that host immune responses also contribute to the clearance of filarial parasites;however,the underlying mechanisms have not been fully elucidated.Main text:Filarial infections caused by Wuchereria bancrofti and Brugia species(lymphatic filariasis)and Onchocerca volvulus(onchocerciasis)affect almost 200 million individuals worldwide and pose major public health challenges in endemic regions.Indeed,the collective disability-adjusted life years for both infections is 3.3 million.Infections with these thread-like nematodes are chronic and,although most individuals develop a regulated state,a portion develop severe forms of pathology.Mass drug administration(MDA)programmes on endemic populations focus on reducing prevalence of people with microfilariae,the worm's offspring in the blood,to less than 1%.Although this has been successful in some areas,studies show that MDA will be required for longer than initially conceived.Conclusion:This paper highlights the mode of action of the various antifilarial treatment strategies and role of host immune response.展开更多
文摘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 IC50s 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.
基金This study was supported by SightSavers International,Ghana and the Centre for Neglected Tropical Diseases,Liverpool School of Tropical MedicineSPB is grateful to the "Amt fur Ausbildungsbeitrage"of the canton of Basel-Stadt for a PhD fellowship.
文摘Background:Mass drug administration(MDA)programmes for the control of lymphatic filariasis in Ghana,have been ongoing in some endemic districts for 16 years.The current study aimed to assess factors that govern the success of MDA programmes for breaking transmission of lymphatic filariasis in Ghana.Methods:The study was undertaken in two"hotspot"districts(Ahanta West and Kassena Nankana West)and two control districts(Mpohor and Bongo)in Ghana.Mosquitoes were collected and identified using morphological and molecular tools.A proportion of the cibarial armatures of each species was examined.Dissections were performed onAnopheles gambiae for filarial worm detection.A questionnaire was administered to obtain information on MDA compliance and vector control activities.Data were compared between districts to determine factors that might explain persistent transmission of lymphatic filariasis.Results:High numbers of mosquitoes were sampled in Ahanta West district compared to Mpohor district(F=16.09,P=0.002).There was no significant difference between the numbers of mosquitoes collected in Kassena Nankana West and Bongo districts(F=2.16,P=0.185).Mansonia species were predominant in Ahanta West district.An.coluzzii mosquitoes were prevalent in all districts.An.melas with infected and infective filarial worms was found only in Ahanta West district.No differences were found in cibarial teeth numbers and shape for mosquito species in the surveyed districts.Reported MDA coverage was high in all districts.The average use of bednet and indoor residual spraying was 82.4 and 66.2%,respectively.There was high compliance in the five preceding MDA rounds in Ahanta West and Kassena Nankana West districts,both considered hotspots of lymphatic filariasis transmission.Conclusions:The study on persistent transmission of lymphatic filariasis in the two areas in Ghana present information that shows the importance of local understanding of factors affecting control and elimination of lymphatic filariasis.Unlike Kassena Nankana West district
文摘Background:There is compelling evidence that not only do anti-filarials significantly reduce larval forms,but that host immune responses also contribute to the clearance of filarial parasites;however,the underlying mechanisms have not been fully elucidated.Main text:Filarial infections caused by Wuchereria bancrofti and Brugia species(lymphatic filariasis)and Onchocerca volvulus(onchocerciasis)affect almost 200 million individuals worldwide and pose major public health challenges in endemic regions.Indeed,the collective disability-adjusted life years for both infections is 3.3 million.Infections with these thread-like nematodes are chronic and,although most individuals develop a regulated state,a portion develop severe forms of pathology.Mass drug administration(MDA)programmes on endemic populations focus on reducing prevalence of people with microfilariae,the worm's offspring in the blood,to less than 1%.Although this has been successful in some areas,studies show that MDA will be required for longer than initially conceived.Conclusion:This paper highlights the mode of action of the various antifilarial treatment strategies and role of host immune response.
