Arylpyrrole and fipronil analogues that inhibit the motility and/or development of Haemonchus contortus in vitro
- Herath, Dilrukshi, Song, Hongjian, Preston, Sarah, Jabbar, Abdul, Wang, Tao, McGee, Sean, Hofmann, Andreas, Garcia-Bustos, Jose, Chang, Bill, Koehler, Anson, Liu, Yuxiu, Ma, Qiaoqiao, Zhang, Penqxiang, Zhao, Qiqi, Wang, Qingmin, Gasser, Robin
- Authors: Herath, Dilrukshi , Song, Hongjian , Preston, Sarah , Jabbar, Abdul , Wang, Tao , McGee, Sean , Hofmann, Andreas , Garcia-Bustos, Jose , Chang, Bill , Koehler, Anson , Liu, Yuxiu , Ma, Qiaoqiao , Zhang, Penqxiang , Zhao, Qiqi , Wang, Qingmin , Gasser, Robin
- Date: 2018
- Type: Text , Journal article
- Relation: International Journal for Parasitology: Drugs and Drug Resistance Vol. 8, no. 3 (2018), p. 379-385
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- Description: Due to widespread drug resistance in parasitic nematodes, there is a need to develop new anthelmintics. Given the cost and time involved in developing a new drug, the repurposing of known chemicals can be a promising, alternative approach. In this context, we tested a library (n = 600) of natural product-inspired pesticide analogues against exsheathed third stage-larvae (xL3s) of Haemonchus contortus (barber's pole worm) using a whole-organism, phenotypic screening technique that measures the inhibition of motility and development in treated larvae. In the primary screen, we identified 32 active analogues derived from chemical scaffolds of arylpyrrole or fipronil. The seven most promising compounds, selected based on their anthelmintic activity and/or limited cytotoxicity, are arylpyrroles that reduced the motility of fourth-stage larvae (L4s) with significant potency (IC 50 values ranged from 0.04 ± 0.01
- Authors: Herath, Dilrukshi , Song, Hongjian , Preston, Sarah , Jabbar, Abdul , Wang, Tao , McGee, Sean , Hofmann, Andreas , Garcia-Bustos, Jose , Chang, Bill , Koehler, Anson , Liu, Yuxiu , Ma, Qiaoqiao , Zhang, Penqxiang , Zhao, Qiqi , Wang, Qingmin , Gasser, Robin
- Date: 2018
- Type: Text , Journal article
- Relation: International Journal for Parasitology: Drugs and Drug Resistance Vol. 8, no. 3 (2018), p. 379-385
- Full Text:
- Reviewed:
- Description: Due to widespread drug resistance in parasitic nematodes, there is a need to develop new anthelmintics. Given the cost and time involved in developing a new drug, the repurposing of known chemicals can be a promising, alternative approach. In this context, we tested a library (n = 600) of natural product-inspired pesticide analogues against exsheathed third stage-larvae (xL3s) of Haemonchus contortus (barber's pole worm) using a whole-organism, phenotypic screening technique that measures the inhibition of motility and development in treated larvae. In the primary screen, we identified 32 active analogues derived from chemical scaffolds of arylpyrrole or fipronil. The seven most promising compounds, selected based on their anthelmintic activity and/or limited cytotoxicity, are arylpyrroles that reduced the motility of fourth-stage larvae (L4s) with significant potency (IC 50 values ranged from 0.04 ± 0.01
Assessing the anthelmintic activity of pyrazole-5-carboxamide derivatives against Haemonchus contortus
- Jiao, Yaqing, Preston, Sarah, Song, Hongjian, Jabbar, Abdul, Liu, Yuxiu, Baell, Jonathan, Hofmann, Andreas, Hutchinson, Dana, Wang, Tao, Koehler, Anson, Fisher, Gillian, Andrews, Katherine, Laleu, Benoit, Palmer, Michael, Burrows, Jeremy, Wells, Timothy, Wang, Qingmin, Gasser, Robin
- Authors: Jiao, Yaqing , Preston, Sarah , Song, Hongjian , Jabbar, Abdul , Liu, Yuxiu , Baell, Jonathan , Hofmann, Andreas , Hutchinson, Dana , Wang, Tao , Koehler, Anson , Fisher, Gillian , Andrews, Katherine , Laleu, Benoit , Palmer, Michael , Burrows, Jeremy , Wells, Timothy , Wang, Qingmin , Gasser, Robin
- Date: 2017
- Type: Text , Journal article
- Relation: Parasites and Vectors Vol. 10, no. 1 (2017), p. 1-7
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- Description: Background: In this study, we tested five series of pyrazole-5-carboxamide compounds (n = 55) for activity against parasitic stages of the nematode Haemonchus contortus (barber’s pole worm), one of the most pathogenic parasites of ruminants. Methods: In an optimised, whole-organism screening assay, using exsheathed third-stage (xL3) and fourth-stage (L4) larvae, we measured the inhibition of larval motility and development of H. contortus. Results: Amongst the 55 compounds, we identified two compounds (designated a-15 and a-17) that reproducibly inhibit xL3 motility as well as L4 motility and development, with IC50 values ranging between ~3.4 and 55.6 μM. We studied the effect of these two ‘hit’ compounds on mitochondrial function by measuring oxygen consumption. This assessment showed that xL3s exposed to each of these compounds consumed significantly less oxygen and had less mitochondrial activity than untreated xL3s, which was consistent with specific inhibition of complex I of the respiratory electron transport chain in arthropods. Conclusions: The present findings provide a sound basis for future work, aimed at identifying the targets of compounds a-15 and a-17 and establishing the modes of action of these chemicals in H. contortus. © 2017 The Author(s).
- Authors: Jiao, Yaqing , Preston, Sarah , Song, Hongjian , Jabbar, Abdul , Liu, Yuxiu , Baell, Jonathan , Hofmann, Andreas , Hutchinson, Dana , Wang, Tao , Koehler, Anson , Fisher, Gillian , Andrews, Katherine , Laleu, Benoit , Palmer, Michael , Burrows, Jeremy , Wells, Timothy , Wang, Qingmin , Gasser, Robin
- Date: 2017
- Type: Text , Journal article
- Relation: Parasites and Vectors Vol. 10, no. 1 (2017), p. 1-7
- Full Text:
- Reviewed:
- Description: Background: In this study, we tested five series of pyrazole-5-carboxamide compounds (n = 55) for activity against parasitic stages of the nematode Haemonchus contortus (barber’s pole worm), one of the most pathogenic parasites of ruminants. Methods: In an optimised, whole-organism screening assay, using exsheathed third-stage (xL3) and fourth-stage (L4) larvae, we measured the inhibition of larval motility and development of H. contortus. Results: Amongst the 55 compounds, we identified two compounds (designated a-15 and a-17) that reproducibly inhibit xL3 motility as well as L4 motility and development, with IC50 values ranging between ~3.4 and 55.6 μM. We studied the effect of these two ‘hit’ compounds on mitochondrial function by measuring oxygen consumption. This assessment showed that xL3s exposed to each of these compounds consumed significantly less oxygen and had less mitochondrial activity than untreated xL3s, which was consistent with specific inhibition of complex I of the respiratory electron transport chain in arthropods. Conclusions: The present findings provide a sound basis for future work, aimed at identifying the targets of compounds a-15 and a-17 and establishing the modes of action of these chemicals in H. contortus. © 2017 The Author(s).
Phenotypic screening of the 'Kurz-box' of chemicals identifies two compounds (BLK127 and HBK4) with anthelmintic activity in vitro against parasitic larval stages of Haemonchus contortus
- Nguyen, Linh, Kurz, Thomas, Preston, Sarah, Brueckmann, Hjoerdis, Lungerich, Beate, Herath, Dilrukshi, Koehler, Anson, Wang, Tao, Skalova, Lenka, Jabbar, Abdul, Gasser, Robin
- Authors: Nguyen, Linh , Kurz, Thomas , Preston, Sarah , Brueckmann, Hjoerdis , Lungerich, Beate , Herath, Dilrukshi , Koehler, Anson , Wang, Tao , Skalova, Lenka , Jabbar, Abdul , Gasser, Robin
- Date: 2019
- Type: Text , Journal article
- Relation: Parasites & Vectors Vol. 12, no. (2019), p. 1-9
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- Description: BackgroundDue to anthelmintic resistance problems, there is a need to discover and develop new drugs for the treatment and control of economically important and pathogenic nematodes of livestock animals. With this focus in mind, we screened 236 compounds from a library (called the Kurz-box') representing chemically diverse classes such as heterocyclic compounds (e.g. thiazoles, pyrroles, quinolines, pyrimidines, benzo[1,4]diazepines), hydoxamic acid-based metalloenzyme inhibitors, peptidomimetics (bis- and tris-pyrimidoneamides, alkoxyamides) and various intermediates on Haemonchus contortus, one of the most important parasitic nematodes of ruminants.MethodsIn the present study, we tested these compounds, and measured the inhibition of larval motility and development of exsheathed third-stage (xL3) and fourth-stage (L4) larvae of H. contortus using an optimised, whole-organism phenotypic screening assay.ResultsOf the 236 compounds, we identified two active compounds (called BLK127 and HBK4) that induced marked phenotypic changes in the worm in vitro. Compound BLK127 induced an eviscerated' phenotype in the xL3 stage and also inhibited L4 development. Compound HBK4 exerted a curved' phenotype in both xL3s and L4s.ConclusionsThe findings from this study provide a basis for future work on the chemical optimisation of these compounds, on assessing the activity of optimised compounds on adult stages of H. contortus both in vitro and in vivo (in the host animal) and against other parasitic worms of veterinary and medical importance.
- Authors: Nguyen, Linh , Kurz, Thomas , Preston, Sarah , Brueckmann, Hjoerdis , Lungerich, Beate , Herath, Dilrukshi , Koehler, Anson , Wang, Tao , Skalova, Lenka , Jabbar, Abdul , Gasser, Robin
- Date: 2019
- Type: Text , Journal article
- Relation: Parasites & Vectors Vol. 12, no. (2019), p. 1-9
- Full Text:
- Reviewed:
- Description: BackgroundDue to anthelmintic resistance problems, there is a need to discover and develop new drugs for the treatment and control of economically important and pathogenic nematodes of livestock animals. With this focus in mind, we screened 236 compounds from a library (called the Kurz-box') representing chemically diverse classes such as heterocyclic compounds (e.g. thiazoles, pyrroles, quinolines, pyrimidines, benzo[1,4]diazepines), hydoxamic acid-based metalloenzyme inhibitors, peptidomimetics (bis- and tris-pyrimidoneamides, alkoxyamides) and various intermediates on Haemonchus contortus, one of the most important parasitic nematodes of ruminants.MethodsIn the present study, we tested these compounds, and measured the inhibition of larval motility and development of exsheathed third-stage (xL3) and fourth-stage (L4) larvae of H. contortus using an optimised, whole-organism phenotypic screening assay.ResultsOf the 236 compounds, we identified two active compounds (called BLK127 and HBK4) that induced marked phenotypic changes in the worm in vitro. Compound BLK127 induced an eviscerated' phenotype in the xL3 stage and also inhibited L4 development. Compound HBK4 exerted a curved' phenotype in both xL3s and L4s.ConclusionsThe findings from this study provide a basis for future work on the chemical optimisation of these compounds, on assessing the activity of optimised compounds on adult stages of H. contortus both in vitro and in vivo (in the host animal) and against other parasitic worms of veterinary and medical importance.
Screening of the ‘Open Scaffolds’ collection from Compounds Australia identifies a new chemical entity with anthelmintic activities against different developmental stages of the barber's pole worm and other parasitic nematodes
- Preston, Sarah, Jiao, Yaqing, Baell, Jonathan, Keiser, Jennifer, Crawford, Simon, Koehler, Anson, Wang, Tao, Simpson, Moana, Kaplan, Ray, Cowley, Karla, Simpson, Kaylene, Hofmann, Andreas, Jabbar, Abdul, Gasser, Robin
- Authors: Preston, Sarah , Jiao, Yaqing , Baell, Jonathan , Keiser, Jennifer , Crawford, Simon , Koehler, Anson , Wang, Tao , Simpson, Moana , Kaplan, Ray , Cowley, Karla , Simpson, Kaylene , Hofmann, Andreas , Jabbar, Abdul , Gasser, Robin
- Date: 2017
- Type: Text , Journal article
- Relation: International Journal for Parasitology: Drugs and Drug Resistance Vol. 7, no. 3 (2017), p. 286-294
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- Description: The discovery and development of novel anthelmintic classes is essential to sustain the control of socioeconomically important parasitic worms of humans and animals. With the aim of offering novel, lead-like scaffolds for drug discovery, Compounds Australia released the ‘Open Scaffolds’ collection containing 33,999 compounds, with extensive information available on the physicochemical properties of these chemicals. In the present study, we screened 14,464 prioritised compounds from the ‘Open Scaffolds’ collection against the exsheathed third-stage larvae (xL3s) of Haemonchus contortus using recently developed whole-organism screening assays. We identified a hit compound, called SN00797439, which was shown to reproducibly reduce xL3 motility by ≥ 70%; this compound induced a characteristic, “coiled” xL3 phenotype (IC50 = 3.46–5.93 μM), inhibited motility of fourth-stage larvae (L4s; IC50 = 0.31–12.5 μM) and caused considerable cuticular damage to L4s in vitro. When tested on other parasitic nematodes in vitro, SN00797439 was shown to inhibit (IC50 = 3–50 μM) adults of Ancylostoma ceylanicum (hookworm) and first-stage larvae of Trichuris muris (whipworm) and eventually kill (>90%) these stages. Furthermore, this compound completely inhibited the motility of female and male adults of Brugia malayi (50–100 μM) as well as microfilariae of both B. malayi and Dirofilaria immitis (heartworm). Overall, these results show that SN00797439 acts against genetically (evolutionarily) distant parasitic nematodes i.e. H. contortus and A. ceylanicum [strongyloids] vs. B. malayi and D. immitis [filarioids] vs. T. muris [enoplid], and, thus, might offer a novel, lead-like scaffold for the development of a relatively broad-spectrum anthelmintic. Our future work will focus on assessing the activity of SN00797439 against other pathogens that cause neglected tropical diseases, optimising analogs with improved biological activities and characterising their targets. © 2017 The Authors
- Authors: Preston, Sarah , Jiao, Yaqing , Baell, Jonathan , Keiser, Jennifer , Crawford, Simon , Koehler, Anson , Wang, Tao , Simpson, Moana , Kaplan, Ray , Cowley, Karla , Simpson, Kaylene , Hofmann, Andreas , Jabbar, Abdul , Gasser, Robin
- Date: 2017
- Type: Text , Journal article
- Relation: International Journal for Parasitology: Drugs and Drug Resistance Vol. 7, no. 3 (2017), p. 286-294
- Full Text:
- Reviewed:
- Description: The discovery and development of novel anthelmintic classes is essential to sustain the control of socioeconomically important parasitic worms of humans and animals. With the aim of offering novel, lead-like scaffolds for drug discovery, Compounds Australia released the ‘Open Scaffolds’ collection containing 33,999 compounds, with extensive information available on the physicochemical properties of these chemicals. In the present study, we screened 14,464 prioritised compounds from the ‘Open Scaffolds’ collection against the exsheathed third-stage larvae (xL3s) of Haemonchus contortus using recently developed whole-organism screening assays. We identified a hit compound, called SN00797439, which was shown to reproducibly reduce xL3 motility by ≥ 70%; this compound induced a characteristic, “coiled” xL3 phenotype (IC50 = 3.46–5.93 μM), inhibited motility of fourth-stage larvae (L4s; IC50 = 0.31–12.5 μM) and caused considerable cuticular damage to L4s in vitro. When tested on other parasitic nematodes in vitro, SN00797439 was shown to inhibit (IC50 = 3–50 μM) adults of Ancylostoma ceylanicum (hookworm) and first-stage larvae of Trichuris muris (whipworm) and eventually kill (>90%) these stages. Furthermore, this compound completely inhibited the motility of female and male adults of Brugia malayi (50–100 μM) as well as microfilariae of both B. malayi and Dirofilaria immitis (heartworm). Overall, these results show that SN00797439 acts against genetically (evolutionarily) distant parasitic nematodes i.e. H. contortus and A. ceylanicum [strongyloids] vs. B. malayi and D. immitis [filarioids] vs. T. muris [enoplid], and, thus, might offer a novel, lead-like scaffold for the development of a relatively broad-spectrum anthelmintic. Our future work will focus on assessing the activity of SN00797439 against other pathogens that cause neglected tropical diseases, optimising analogs with improved biological activities and characterising their targets. © 2017 The Authors
Selected alpha-pyrones from the plants Cryptocarya novoguineensis (Lauraceae) and Piper methysticum (Piperaceae) with activity against Haemonchus contortus in vitro
- Herath, Dilrukshi, Preston, Sarah, Jabbar, Abdul, Garcia-Bustos, Jose, Addison, Russell, Hayes, Sasha, Rali, Topul, Wang, Tao, Koehler, Anson, Chang, Bill, Hofmann, Andreas, Davis, Rohan, Gasser, Robin
- Authors: Herath, Dilrukshi , Preston, Sarah , Jabbar, Abdul , Garcia-Bustos, Jose , Addison, Russell , Hayes, Sasha , Rali, Topul , Wang, Tao , Koehler, Anson , Chang, Bill , Hofmann, Andreas , Davis, Rohan , Gasser, Robin
- Date: 2019
- Type: Text , Journal article
- Relation: International Journal for Parasitology-Drugs and Drug Resistance Vol. 9, no. (2019), p. 72-79
- Full Text:
- Reviewed:
- Description: Due to the widespread occurrence and spread of anthelmintic resistance, there is a need to develop new drugs against resistant parasitic nematodes of livestock animals. The Nobel Prize-winning discovery and development of the anti-parasitic drugs avermectin and artemisinin has renewed the interest in exploring natural products as anthelmintics. In the present study, we screened 7500 plant extracts for in vitro-activity against the barber's pole worm, Haemonchus contortus, a highly significant pathogen of ruminants. The anthelmintic extracts from two plants, Cryptocarya novoguineensis and Piper methysticum, were fractionated by high-performance liquid chromatography (HPLC). Subsequently, compounds were purified from fractions with significant biological activity. Four alpha-pyrones, namely goniothalamin (GNT), dihydrokavain (DHK), desmethoxyyangonin (DMY) and yangonin (YGN), were purified from fractions from the two plants, GNT from C. novoguineensis, and DHK, DMY and YGN (= kavalactones) from P. methysticum. The three kavalactones induced a lethal, eviscerated (Evi) phenotype in treated exsheathed third-stage larvae (xL3s), and DMY and YGN had moderate potencies (IC50 values of 31.7 +/- 0.23 mu M and 23.7 +/- 2.05 mu M, respectively) at inhibiting the development of xL3s to fourth-stage larvae (L4s). Although GNT had limited potency (IC50 of 200-300 mu M) at inhibiting L4 development, it was the only compound that reduced L4 motility (IC50 of 6.25-12.50 mu M). The compounds purified from each plant affected H. contortus in an irreversible manner. These findings suggest that structure-activity relationship studies of alpha-pyrones should be pursued to assess their potential as anthelmintics.
- Authors: Herath, Dilrukshi , Preston, Sarah , Jabbar, Abdul , Garcia-Bustos, Jose , Addison, Russell , Hayes, Sasha , Rali, Topul , Wang, Tao , Koehler, Anson , Chang, Bill , Hofmann, Andreas , Davis, Rohan , Gasser, Robin
- Date: 2019
- Type: Text , Journal article
- Relation: International Journal for Parasitology-Drugs and Drug Resistance Vol. 9, no. (2019), p. 72-79
- Full Text:
- Reviewed:
- Description: Due to the widespread occurrence and spread of anthelmintic resistance, there is a need to develop new drugs against resistant parasitic nematodes of livestock animals. The Nobel Prize-winning discovery and development of the anti-parasitic drugs avermectin and artemisinin has renewed the interest in exploring natural products as anthelmintics. In the present study, we screened 7500 plant extracts for in vitro-activity against the barber's pole worm, Haemonchus contortus, a highly significant pathogen of ruminants. The anthelmintic extracts from two plants, Cryptocarya novoguineensis and Piper methysticum, were fractionated by high-performance liquid chromatography (HPLC). Subsequently, compounds were purified from fractions with significant biological activity. Four alpha-pyrones, namely goniothalamin (GNT), dihydrokavain (DHK), desmethoxyyangonin (DMY) and yangonin (YGN), were purified from fractions from the two plants, GNT from C. novoguineensis, and DHK, DMY and YGN (= kavalactones) from P. methysticum. The three kavalactones induced a lethal, eviscerated (Evi) phenotype in treated exsheathed third-stage larvae (xL3s), and DMY and YGN had moderate potencies (IC50 values of 31.7 +/- 0.23 mu M and 23.7 +/- 2.05 mu M, respectively) at inhibiting the development of xL3s to fourth-stage larvae (L4s). Although GNT had limited potency (IC50 of 200-300 mu M) at inhibiting L4 development, it was the only compound that reduced L4 motility (IC50 of 6.25-12.50 mu M). The compounds purified from each plant affected H. contortus in an irreversible manner. These findings suggest that structure-activity relationship studies of alpha-pyrones should be pursued to assess their potential as anthelmintics.
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