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Isorhamnetin: A Nematocidal Flavonoid from Prosopis Laevigata Leaves Against Haemonchus Contortus Eggs and Larvae. Biomolecules 2020; 10:biom10050773. [PMID: 32429307 PMCID: PMC7277221 DOI: 10.3390/biom10050773] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 12/16/2022] Open
Abstract
Haemonchus contortus affect small ruminants all over the world. Anthelmintics cause resistance, contamination, and a risk of public health. Prosopis laevigata is a plant used as a home remedy against many diseases in Mexico. This study arose from a preliminary study where a P. laevigata hydroalcoholic extract (Pl-hae) showed anthelmintic activity (aa) against H. contortus. Searching for bioactive compounds (bac) with high aa, the Pl-hae was fractioned obtaining an aqueous (Aq-F) and an ethyl acetate fraction (EtAc-F), and a flavonoid with aa identified as isorhamnetin was obtained from EtAc-F. Both fractions were in vitro assessed by the egg hatch test (eht) and larval mortality (lm) assays. The bac obtained from EtAc-F were characterised by NMR analysis. The highest aa were recorded with EtAc-F, resulting in 100% eht and 80.45% lm at 0.75 and 30 mg/mL, respectively. Alterations in eggs and larvae attributed to isorhamnetin were recorded by environmental scanning electron microscopy, confocal laser scanning and by high-resolution digital-coupled camera. This flavonoid caused 100% eht at 0.07 mg/mL after 48 h and 100% lm at 7.5 mg/mL after 72 h exposure. Isorhamnetin has promising potential as an anthelmintic against sheep haemonchosis.
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Molan AL, Balasim MQ, Al-Bayati NY. Insecticidal Activity of Grape Pomaces from Two Grape Cultivars Against the Housefly ( Musca domestica L .) Under Laboratory Conditions. Trop Life Sci Res 2018; 29:89-102. [PMID: 30112143 PMCID: PMC6072721 DOI: 10.21315/tlsr2018.29.2.7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Aqueous extracts prepared from the powdered entire pomaces and their parts (seeds and peels) of two Iraqi grape cultivars (Shada and Des-Alanez) were evaluated for their ovicidal, larvicidal, and pupicidal activities against housefly, Musca domestica (Linnaeus 1758) and compared them with chemical insecticide (Agita 10 WG; Austria). The highest insecticidal activity was shown by the aqueous extracts of powdered seeds followed by the entire pomace and then peels. The water extracts from the seeds, peels and pomaces were able to inhibit completely the hatching of the eggs at a concentration of 150 μg/ml while the Agita insecticide was able to inhibit the hatching process at a concentration of 50 μg/ml. The water extracts also were able to kill the L3 larvae and the activity was increasing with the increasing of the concentration. It is very interesting to note that the addition of the powdered entire pomaces, seeds, and peels on top or at the bottom of the cow manure was able to inhibit the development of up to 50% and 47.5% of L1 to pupae and to adult flies, respectively. Taking into consideration the huge amounts of grape pomaces that produced annually, the cheap price and the ease in dealing with, make them a good candidate as alternative insecticides and environmentally more friendly than the chemical insecticides.
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Affiliation(s)
- Abdul-Lateef Molan
- Department of Biotechnology, College of Sciences, Diyala University, Diyala, Iraq
| | - Mohamad Q. Balasim
- Department of Biology, College of Education for Pure Sciences, Diyala University, Diyala, Iraq
| | - Nagham Y. Al-Bayati
- Department of Biology, College of Education for Pure Sciences, Diyala University, Diyala, Iraq
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Molan AL, Faraj AM. The effects of condensed tannins extracted from different plant species on egg hatching and larval development of Teladorsagia circumcincta (Nematoda: Trichostrongylidae). Folia Parasitol (Praha) 2010; 57:62-8. [PMID: 20450000 DOI: 10.14411/fp.2010.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effects of condensed tannins (CTs) extracted from five species of plants on egg hatching and larval development of Teladorsagia circumcincta (Stadelmann, 1894) (syn. Ostertagia circumcincta) were evaluated using in vitro bioassays. The extracts of CTs were obtained from Lotus pedunculatus (LP), Lotus corniculatus (LC), Dorycnium pentaphyllum (DP), Dorycnium rectum (DR) and Rumex obtusifolius (RO). The results of egg hatching assay showed that about 53%, 68%, 51%, 60% and 46% of the eggs hatched when in vitro incubations contained 900 microg/ml of CTs from LP, LC, DP, DR and RO, respectively (P < 0.001 relative to control incubation), while in control incubations (no CT added) 87% of the eggs hatched. In the larval development assay, development was allowed to proceed for 7 days, by which time 89% of the hatched larvae in control wells (no CTs) had reached the infective third stage (L3). In incubations containing 200 microg CT from LP, LC, DP, DR and RO/ml, about 8%, 15%, 14%, 8% and 4% of the eggs attained full development to L3 larvae, respectively (P < 0.001 relative to control incubation). Only 1% of the eggs were able to develop to L3 larvae in incubations containing 400 microg CT extracted from LC/ml, whilst in the incubations containing the same concentration of other CTs the eggs were not able to develop to L3 larvae. It seems that CTs are not only slowing down the larval development but also kill the undeveloped larvae. At 400 microg/ml, for example, CT from LP, LC, DP, DR and RO killed 67%, 48%, 68%, 93% and 91% of first-stage (L1) and second-stage (L2) larvae, respectively. This study shows that CTs are able to disrupt the life cycle of nematodes.
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Affiliation(s)
- Abdul-Lateef Molan
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand.
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Brunet S, Aufrere J, El Babili F, Fouraste I, Hoste H. The kinetics of exsheathment of infective nematode larvae is disturbed in the presence of a tannin-rich plant extract (sainfoin) both in vitro and in vivo. Parasitology 2007; 134:1253-62. [PMID: 17346358 DOI: 10.1017/s0031182007002533] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
SUMMARYThe mode of action of bioactive plants on gastrointestinal nematodes remains obscure. Previous in vitro studies showed that exsheathment was significantly disturbed after contact with tannin-rich extracts. However, the role of important factors (extract concentration, parasite species) has not been assessed and no information is available on the occurrence in vivo. These questions represent the objectives of this study. The model incorporated the parasites Haemonchus contortus and Trichostrongylus colubriformis with sainfoin as the bioactive plant. A set of in vitro assays was performed, measuring the changes observed, after 3 h of contact with increasing concentrations of sainfoin, on the rate of artificial exsheathment. The results indicated that sainfoin extracts interfered with exsheathment in a dose-dependent manner and the process overall was similar for both nematodes. The restoration of control values observed after adding PEG to extracts confirms a major role for tannins. A second study was performed in vivo on rumen-cannulated sheep fed with different proportions of sainfoin in the diet to verify these in vitro results. The consumption of a higher proportion of sainfoin was indeed associated with significant delays in Haemonchus exsheathment. Overall, the results confirmed that interference with the early step of nematode infection might be one of the modes of action that contributes to the anthelmintic properties of tanniniferous plants.
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Affiliation(s)
- S Brunet
- Unité Mixte de Recherches 1225 INRA/DGER, Interactions Hôte Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, 23 chemin des Capelles, 31076 Toulouse, France
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Stromberg BE, Gasbarre LC. Gastrointestinal Nematode Control Programs with an Emphasis on Cattle. Vet Clin North Am Food Anim Pract 2006; 22:543-65. [PMID: 17071352 DOI: 10.1016/j.cvfa.2006.08.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Control strategies for nematode parasites rely on knowledge of the relationships between the parasites and their hosts. Specifically, these programs are based on identifying crucial points of interaction in the environment provided by the host, including genetics and the immune response, and critical periods in the physical environment in which the eggs and larval stages must develop. When these targets are identified and the interactions understood, cost-effective sustainable programs can be developed using currently available antiparasitic compounds. Resistance to the major classes of anthelmintic compounds requires consideration of new approaches, such as immunity or genetics of the host. Additionally, the efficacy of these compounds can be expanded with combined or concomitant use. Increased study of the use of novel approaches, including fungi, elements such as copper, and plant products, has also occurred. This article explores each of these areas to allow readers to appreciate how various approaches may be developed and incorporated into an effective parasite control program.
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Affiliation(s)
- Bert E Stromberg
- Veterinary and Biomedical Sciences Department, College of Veterinary Medicine, University of Minnesota, 1971 Commonwealth Avenue, St. Paul, MN 55108, USA.
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Pokharel DR, Rai R, Kumar P, Chaturvedi CM, Rathaur S. Tissue localization of collagenase and leucine aminopeptidase in the bovine filarial parasite Setaria cervi. FILARIA JOURNAL 2006; 5:7. [PMID: 16716219 PMCID: PMC1481592 DOI: 10.1186/1475-2883-5-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Accepted: 05/22/2006] [Indexed: 11/10/2022]
Abstract
BACKGROUND Like other helminth proteases, filarial proteases have also been shown to require for parasite survival inside the host and mediate various physiologic processes such as tissue invasion, feeding, embryogenesis and host immune evasion. Many of these proteases have shown potential for vaccines and chemotherapeutic agents against active filarial infections. Setaria cervi is a bovine filarial parasite and serves as a good parasite model for the studies in lymphatic filariasis. Recently, a 175 kDa collagenase and leucine aminopeptidase (LAP) have been purified and characterized from the bovine filarial parasite S. cervi and shown to be potential vaccine candidate and diagnostic marker, respectively for human lymphatic filariasis. However, their tissue localizations and putative roles in the parasite biology have not yet been examined and thus remain unclear. Therefore, the current study attempts to localize and explore the putative roles of these two enzymes in S. cervi. METHODS The tissue distributions of 175 kDa collagenase and leucine aminopeptidase in S. cervi were examined by immunohistochemical and histochemical methods, respectively. Immune sera obtained from the jirds immunized with collagenase served as primary antibody, rabbit anti-mouse IgG-HRP conjugate as secondary antibody and DAB as the substrate for the immunostaining of collagenase. Leu-betaNA was used as the substrate for the histochemical staining of LAP. RESULTS Both the collagenase and LAP were present in the body wall; however, they differ in their distribution pattern in different layers of body wall. Collagenase was mainly localized in epicuticle, cuticle, syncytial hypodermis and the nerve cord region whereas LAP was more concentrated in epicuticle, longitudinal muscle layers and almost absent or very faintly stained in syncytial hypodermis and nerve cord region. Both collagenase and LAP showed their common distributions in intestine, uterus and mature eggs, growing embryos and mf. Very strong immunostaining of collagenase in the outer body surface of the parasite indicates its major role in host-parasite relationship whereas the presence of LAP in muscular region suggests its role in tissue remodeling. The common presences of collagenase and LAP in the S. cervi intestine, ovary, uterus, eggs and mf suggest that they also have collaborative roles in molting, nutrition and embryogenesis. The data obtained on their immunological characterizations and their presence in important parasite organs give strong indication that they are critical for the survival of filarial parasite and thus can be good vaccine candidates and/or diagnostic markers for human lymphatic filariasis. CONCLUSION The manuscript reports for the first time the tissue distribution of collagenase and LAP in the bovine filarial parasite S. cervi and discuss their putative roles in vivo. Our findings also open the avenue to examine the roles of these two proteases in vivo, which will require further experiments like using their natural substrates and/or specific inhibitors in each tissues.
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Affiliation(s)
- Daya R Pokharel
- Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi-221005, India
| | - Reeta Rai
- Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi-221005, India
| | - Pankaj Kumar
- Department of Zoology, Faculty of Science, Banaras Hindu University, Varanasi-221005, India
| | - C M Chaturvedi
- Department of Zoology, Faculty of Science, Banaras Hindu University, Varanasi-221005, India
| | - Sushma Rathaur
- Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi-221005, India
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Ikeda T. Effects of L-type Ca2+ channel antagonists on in vitro excystment of Paragonimus ohirai metacercariae induced by sodium cholate. Parasitol Res 2006; 99:336-40. [PMID: 16565818 DOI: 10.1007/s00436-005-0080-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Accepted: 10/26/2005] [Indexed: 10/24/2022]
Abstract
The inhibitory effects of L-type Ca2+ channel antagonists on Na cholate-induced in vitro excystment (CIIE) of Paragonimus ohirai metacercariae were studied. At concentrations of 10 microM, nicardipine and nimodipine inhibited CIIE completely and by approximately 92%, respectively. Nitrendipine and (+/-)-verapamil inhibited CIIE by about one half and one third, respectively. Nifedipine and diltiazem did not inhibit CIIE significantly. At higher concentrations, nitrendipine at 20 microM completely inhibited CIIE, and (+/-)-verapamil at 40 microM inhibited CIIE by 93%. Nifedipine and diltiazem inhibited CIIE only slightly and little, respectively, even at 40 microM. Complete inhibition by nicardipine at 10 microM required preincubation of metacercariae with the antagonist for 15 min. The inhibitory effects of nicardipine and nimodipine were reversible, and most of the nimodipine-treated metacercariae could excyst within 1 h after being washed, but the nicardipine-treated ones started to excyst 1 h after washing. Nicardipine suppressed the active movement of encysted juveniles evoked by Na cholate, whereas nimodipine did not suppress this significantly. These results suggested that L-type Ca2+ channels appeared to be involved in CIIE of P. ohirai metacercariae and that the inhibitory effect of the channels was due primarily to factors other than the inhibition of muscular activity, probably involving the secretion and release of enzymes lytic against the metacercarial cyst wall.
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Affiliation(s)
- Teruaki Ikeda
- Department of Medical Zoology, Kanazawa Medical University, Uchinada, Ishikawa, 920-0293, Japan.
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Bahuaud D, Martinez-Ortiz de Montellano C, Chauveau S, Prevot F, Torres-Acosta F, Fouraste I, Hoste H. Effects of four tanniferous plant extracts on thein vitroexsheathment of third-stage larvae of parasitic nematodes. Parasitology 2006; 132:545-54. [PMID: 16388690 DOI: 10.1017/s0031182005009509] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 09/12/2005] [Accepted: 10/17/2005] [Indexed: 11/07/2022]
Abstract
The anthelmintic properties of tanniferous plants and of their secondary metabolites represent one possible alternative to chemotherapy that is currently being explored as a means of achieving sustainable control of gastrointestinal nematodes in ruminants. Previousin vivoandin vitroresults suggest that tanniferous plants can have direct anti-parasitic effect against different stages of nematodes. However, the mode of action of the bioactive plant compounds remains obscure. The objectives of the current study were (1) to examine the hypothesis that extracts of tanniferous plants might interfere with the exsheathment of third-stage infective larvae (L3); (2) to assess the role of tannins in the process by examining the consequence of adding an inhibitor of tannins (polyethylene glycol: PEG) to extracts. The effects of 4 tanniferous plant extracts on exsheathment have been examined on L3 ofHaemonchus contortusandTrichostrongylus colubriformis. Artificial exsheathment was inducedin vitroby adding hypochloride solution to larval suspension. The evolution of exsheathment with time was measured by repeated observations at 10-min interval for 60 min. The selected plants were: genista (Sarothamnus scoparius), heather (Erica erigena), pine tree (Pinus sylvestris), and chestnut tree (Castanea sativa), with tannin contents ranging from 1·5 to 24·7% of DM. Extracts of a non-tanniferous plant (rye grass, tannin content: 0·3% of DM) were included in the assay as negative controls. The extracts were tested at the concentration of 600 μg/ml and the effects were compared to the rate of exsheathment of control larvae in PBS. No statistical differences in the pattern of exsheathment was observed after addition of rye grass or genista extracts for both nematode species and with heather extracts forT. colubriformis. In contrast, pine tree extracts on larvae of both species and heather extracts withH. contortusinduced a significant delay in exsheathment. Last, contact with chest nut extracts led to a total inhibition of the process for both nematodes. These results suggest that extracts of tanniferous plants might affect a key process in the very early stages of larval invasion of the host. In most cases, the addition of PEG led to a total or partial restoration towards control values. This suggests that tannins are largely involved in the inhibitory process. However, other secondary metabolites may also interfere with the process that would help to explain some of the differences in response observed between the two nematode species.
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Affiliation(s)
- D Bahuaud
- Unité Mixte de Recherche 1225 INRA/DGER, 23, Chemin des Capelles, 31076 Toulouse Cedex, France
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Abstract
Extended use of oral contraceptive (OC) pills can successfully suppress endometrial activity and prevent menstruation for several months. Given that missed menses in women not using hormonal contraception may be of medical concern, understanding how hormonal contraceptives eliminate these concerns is important for both patient and healthcare provider acceptance. OC withdrawal bleeding is an artificial, iatrogenic event, which results from the deliberate, periodic interruption of hormonal support of the endometrium. Historically, it was important to provide periodic bleeding to reassure OC efficacy, but today it is recognized that these bleeding episodes are medically unnecessary and cause patient discomfort and out-of-pocket expenses. Decades of experience with prolonged use of OCs have been accumulated for women with specific menstrual-related problems such as endometriosis, dysmenorrhea, and menstrual migraine headaches. Today there is a US FDA-approved product to routinely reduce the number of withdrawal periods. Clinical trials show that there is an initial increase in unscheduled bleeding and spotting days with extended-cycle OC use, but an absolute decrease in total days of bleeding and spotting from the first cycle of use. Over time, unscheduled bleeding and spotting decreases to rates found with the use of conventional-cycle regimens. Every woman who is interested in using OC pills should be offered the opportunity to choose how to use them, to determine if and when she will have withdrawal bleeding.
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Affiliation(s)
- Anita L Nelson
- Harbor-UCLA Medical Center, Torrance, California 90209-2910, USA.
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Ikeda T. Effects of blockers of Ca2+ channels and other ion channels on in vitro excystment of Paragonimus ohirai metacercariae induced by sodium cholate. Parasitol Res 2004; 94:329-31. [PMID: 15449179 DOI: 10.1007/s00436-004-1218-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2004] [Accepted: 08/11/2004] [Indexed: 10/26/2022]
Abstract
The inhibitory effects of various ion channel blockers were examined on in vitro excystment of Paragonimus ohirai metacercariae induced by a bile salt, sodium cholate. At a concentration of 10 microM, bepridil, a non-selective Ca(2+) channel blocker, completely inhibited in vitro excystment, whereas TEA, lidocaine, and R(+)-IAA-94, channel blockers against K(+), Na(+) and Cl(-) ions, respectively, benzamil, an Na(+)/H(+) and Na(+)/Ca(2+) ion exchanger blocker, and R(+)-DIOA, a [K(+), Cl(-)] cotransporter inhibitor, did not. Considering the previous result that Ca(2+) ionophores are also efficient inducing factors for in vitro excystment of P. ohirai metacercariae and the present result, bile salts appear to induce the excystment of P. ohirai metacercariae through evoking the Ca(2+) channels of target cells within the metacercarial juveniles.
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Affiliation(s)
- Teruaki Ikeda
- Department of Medical Zoology, Kanazawa Medical University, Uchinada, 920-0293, Ishikawa, Japan.
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Abstract
There is a great deal of empirical data and theoretical predictions on the patterns and processes of trematode behaviour, particularly in relation to host-finding activities by the free-living stages and site-finding migrations by the parasitic stages within their hosts. Ecological and evolutionary models of trematode life histories often make explicit assumptions about how these organisms must perceive and respond to signals in their worlds as they move from host to host and as they parasitize each host. Nevertheless, it is unclear how natural selection shapes the parasites' behavioural strategies. In addition, at each stage in their life cycle, trematodes are adorned with elaborate sensory organs and possess sophisticated neuromuscular systems, but it is not clear how they use these complex machinery to perceive their worlds. The purpose of this review is to address this question through insights gathered from a century of research on trematode behaviour. Core theoretical assumptions from modern animal behaviour are used to provide the context for this analysis; a key concept is that all animals have unique perceptual worlds that may be inferred from their behaviours. A critical idea is that all animals possess complex patterns of innate behaviour which can be released by extremely specific signals from the environment. The evidence suggests that trematode parasites live in ecologically predictable aquatic and internal host environments where they perceive only small subsets of the total information available from the environment. A general conclusion is that host finding in miracidia and cercaria, and site-finding by trematodes migrating within their definitive hosts, is accomplished through the release of innate patterns of behaviours which are adaptive within the context of conditions in the worm's environment. Examples from empirical studies are used to support the contention that, despite the apparent complexity of their free-living and parasitic environments, the perceptual worlds of trematodes are impoverished, and complex patterns of behaviour may be released by only a few signals in their environment.
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Ikeda T. Involvement of cysteine proteinases in excystment of Paragonimus ohirai metacercariae induced by sodium cholate and A23187. J Helminthol 2003; 77:21-6. [PMID: 12590660 DOI: 10.1079/joh2002144] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The involvement of intrinsic proteinases in the excystment of Paragonimus ohirai metacercariae was studied in in vitro excystment induced by sodium (Na) cholate, a bile salt and A23187, a Ca2+ ionophore. The effects of various proteinase inhibitors on the in vitro excystment were examined and similar inhibitory profiles were obtained. Benzyloxycarbonyl-L-leucyl-L-leucinal (Z-Leu-Leu-H), a cysteine proteinase inhibitor and 4-(2-aminoethyl)-benzenesulfonyl fluoride (Pefabloc SC), a serine proteinase inhibitor completely inhibited excystment, while L-3-carboxy-2,3-trans-epoxypropionyl-leucylamido (4-guanidino)-butane (E-64), a cysteine proteinase inhibitor and leupeptin, a cysteine/serine proteinase inhibitor permitted partial excystment at a lower rate, but inhibited it from proceeding from the partial excystment stage. In secretions released from metacercariae during excystment, proteinase activities detected towards various fluorogenic peptidyl substrates were almost completely inhibited by Z-Leu-Leu-H and E-64, but not by Pefabloc SC. Sodium cholate induced a higher secretion of cysteine proteinases and a higher rate of excystment than A23187. Profiles of cysteine proteinase activities towards five peptidyl substrates detected were markedly different among the two secretions and the lysate of newly excysted juveniles. Newly excysted juveniles released cysteine proteinases with similar activity profiles and levels to metacercariae induced by Na cholate-incubation, whereas the release of cysteine proteinases was reduced compared with metacercariae induced by A23187-incubation. These results provide valuable information about the involvement of intrinsic proteinases in metacercarial excystment.
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Affiliation(s)
- T Ikeda
- Department of Medical Zoology, Kanazawa Medical University, Uchinada, Ishikawa, 920-0293, Japan.
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Sciacca J, Forbes WM, Ashton FT, Lombardini E, Gamble HR, Schad GA. Response to carbon dioxide by the infective larvae of three species of parasitic nematodes. Parasitol Int 2002; 51:53-62. [PMID: 11880227 DOI: 10.1016/s1383-5769(01)00105-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The response of infective third-stage larvae (L3) of three species of parasitic nematodes, Ancylostoma caninum, Strongyloides stercoralis, and Haemonchus contortus to carbon dioxide (CO(2)) at physiological concentrations was investigated. L3 of the skin-penetrating species, A. caninum and S. stercoralis, were stimulated by CO(2) at the concentration found in human breath (3.3-4%); these larvae responded by crawling actively, but not directionally. Crawling was not stimulated by breath passed through a CO(2)-removing "scrubber" or by "bench air". Both A. caninum and S. stercoralis L3 stopped crawling when exposed to 5% CO(2) for 1 min. L3 of A. caninum became active 9-14 min after exposure to 5% CO(2) ended, but activity resumed more rapidly (10-15 s) if larvae were subsequently exposed to breath or breath through the scrubber. L3 of S. stercoralis resumed crawling 30-35 s after exposure to 5% CO(2), but resumed crawling within a very few seconds when exposed to breath or breath through the scrubber. Thus, while 5% CO(2) was inhibitory, lower concentrations of this gas stimulated L3 of both species. Apparently, exposing immobilized larvae to breath or breath through the scrubber causes the environmental CO(2) concentration to drop to a level that is stimulatory. The L3 of H. contortus ceased crawling and coiled when exposed to human breath or to 1% CO(2), but continued to move within the coil in both cases. The crawling response of the L3 of the two skin-penetrating species, A. caninum and S. stercoralis, to stimulation by CO(2) probably relates to their active host-finding behavior, while the cessation response elicited by CO(2) in H. contortus larvae may relate to the fact that they rely on passive ingestion by a ruminant host.
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Affiliation(s)
- Joslyn Sciacca
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce St., Philadelphia, PA 19104, USA
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Molan AL, Waghorn GC, McNabb WC. Effect of condensed tannins on egg hatching and larval development of Trichostrongylus colubriformis in vitro. Vet Rec 2002; 150:65-9. [PMID: 11837588 DOI: 10.1136/vr.150.3.65] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The effects of condensed tannins extracted from seven forages on the viability of the eggs and first stage (L1) larvae of the sheep nematode Trichostrongylus colubriformis were evaluated in in vitro assays. The extracts of condensed tannins were obtained from Lotus pedunculatus (LP), Lotus corniculatus (LC), sulla (Hedysarum coronarium), sainfoin (Onobrychus viciifolia), Dorycnium pentaphylum (DP), Dorycnium rectum (DR) and dock (Rumex obtusifolius). Extracts containing 200 to 500 microg/ml reduced the proportion of eggs that hatched. The larval development assay was used to evaluate the effect of the extracts on the development of either eggs or L1 larvae to L3 infective larvae. Development was allowed to proceed for seven days by which time the larvae in control incubations had reached the infective L3 stage. Extracts containing 200 microg/ml from LP, DP, DR or dock prevented egg development, and only 11, 8 and 2 per cent of the eggs developed to L3 larvae with extracts from LC, sulla and sainfoin, respectively. When the concentration was 400 microg/ml no eggs developed to L3 larvae. The addition of the extracts after hatching also inhibited the development of L1 to L3 larvae; 200 microg/ml extracted from LP, LC, sulla, sainfoin, DP, DR and dock resulted in only 14, 18, 17, 15, 14, 16 and 4 per cent of L1 larvae developing to the L3 stage compared with 85 per cent for controls, and 400 microg/ml further reduced the development of L1 larvae. Statistical analyses showed that when the extracts were added before hatching they were significantly (P<0.001) more effective at inhibiting the larval development than when they were added after hatching. The condensed tannins from dock had the greatest inhibitory effect on egg development followed by the tannins from DR, sainfoin, DP, LP, sulla and LC.
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Affiliation(s)
- A L Molan
- Nutrition and Behaviour Group, AgResearch Grasslands Research Centre, Palmerston North, New Zealand
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15
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Abstract
In vitro excystation studies were carried out on the metacercariae cysts of Paragonimus heterotremus obtained from naturally infected crabs Potamon spp. The effects of elastase, trypsin, trypsin-dog bile, trypsin-bile salt, and dithiothreitol (DTT) were examined. The trypsin-dog bile medium stimulated maximum excystation. Of the media that contained 1 mM DTT, the optimum conditions for the excystation were shown to be pH 9, temperature of 39-40 C, and osmolarity of 250-350 mOsm. The DTT acceleration was antagonized by all of the following 6 protease inhibitors: leupeptin (0.5-4 microg/ml), L-trans-epoxysuccinyl leucylamido (4-guanidine) butane (1-8 microM), N-tosyl-L-phenylalanine chloromethyl ketone (0.1-0.4 mM), N alpha-p-tosyl-L-lysine chloromethyl ketone (25-200 microg/ml), iodoacetic acid (0.5-4 mM), and phenylmethylsulfonyl fluoride (1-4 mM). These results suggest that a number of extrinsic and intrinsic factors may modulate excystation.
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Affiliation(s)
- P M Intapan
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Thailand
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16
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Young AR, Mancuso N, Bowles VM. Biochemical aspects of egg hatch in endo- and ectoparasites: potential for rational drug design. Int J Parasitol 1999; 29:861-7. [PMID: 10480723 DOI: 10.1016/s0020-7519(99)00056-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Control of parasites through rational drug design requires a thorough understanding of the parasite's lifecycle encompassing the biochemical and physiological processes which contribute to normal parasite homeostasis. The hatching of parasite eggs for example, represents an important process in the development of a parasitic infection. Previous studies in helminths have indicated that secreted enzymes often facilitate successful endoparasite egg hatch. In contrast, there are relatively few examples demonstrating a role for secreted enzymes in the egg hatching process of insects. An analysis of this process in the ectoparasite Lucilia cuprina suggests a role for secreted enzymes in the hatching of sheep blowfly eggs. Characterisation of the proteases collected at the time of egg hatch indicates the presence of serine proteases. Further purification and characterisation of these proteases may enable the design of specific inhibitors to interfere with the egg hatch process and therefore provide a novel means of control.
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Affiliation(s)
- A R Young
- Centre for Animal Biotechnology, The University of Melbourne, Parkville, Australia
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17
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Hawdon JM, Jones BF, Hoffman DR, Hotez PJ. Cloning and characterization of Ancylostoma-secreted protein. A novel protein associated with the transition to parasitism by infective hookworm larvae. J Biol Chem 1996; 271:6672-8. [PMID: 8636085 DOI: 10.1074/jbc.271.12.6672] [Citation(s) in RCA: 198] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The developmentally arrested third stage infective larva of hookworms resumes development upon entry into the definitive host. This transition to parasitism can be modeled in vitro by stimulating infective larvae with a low molecular weight ultrafiltrate of host serum together with methylated glutathione analogues. When stimulated to resume development in vitro, activated larvae of the hookworm Ancylostoma caninum released a 42-kDa protein, termed Ancylostoma-secreted protein (ASP). ASP was the major protein released by activated hookworm larvae. Degenerate oligonucleotide primers, based on a partial internal amino acid sequence of the protein, were used together with flanking vector sequence primers to amplify a fragment from a third stage larval cDNA library by polymerase chain reaction. The fragment was used as a probe to isolate a longer clone from the larval cDNA library. The full-length ASP cDNA was found to encode a 424-amino acid protein with homology to the antigen 5/antigen 3 family of proteins from hymenopteran venoms and a family of cysteine-rich secretory proteins. ASP was expressed in bacterial cells, and a polyclonal antiserum against purified recombinant ASP was produced. The antiserum, which was demonstrated to be specific for ASP, was used as a probe to measure the kinetics of ASP release by hookworm larvae. ASP is released within 30 min of stimulation, with the majority released by 4 h. Low levels of ASP were released continuously following activation, but only if the stimuli were present in the incubation medium. The compound 4,7-phenanthroline, previously shown to inhibit larval activation, also inhibited release of ASP. The specific, rapid release of ASP by activated infective larvae suggests that this molecule occupies a critical and central role in the transition from the external environment to parasitism.
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Affiliation(s)
- J M Hawdon
- Medical Helminthology Laboratory, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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18
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Affiliation(s)
- B Fried
- Department of Biology, Lafayette College, Easton, Pennsylvania 18042
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19
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Haas W. Physiological analyses of host-finding behaviour in trematode cercariae: adaptations for transmission success. Parasitology 1994; 109 Suppl:S15-29. [PMID: 7854848 DOI: 10.1017/s003118200008505x] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Physiological analyses of the behaviour of several cercarial species which actively find and invade their hosts have revealed very complex sequences of behaviour patterns and responses to very different stimuli from the environment and the host. A result of these physiological studies is that the behaviour patterns of each of the species investigated are surprisingly individual. The behavioural patterns of host-finding of those species analysed in some detail reveal profound adaptations to maximize transmission success. This can be demonstrated for movement patterns during swimming, for responses to environmental conditions such as gravity, light and temperature, for responses to stimuli emanating from the host such as shadows, water turbulence and chemical compounds and especially for the responses after contact with the host. The behaviour patterns can be interpreted as adaptations to: (1) dispersal by leaving the habitat of the snail intermediate host and distribution within the area; (2) long survival by energy saving swimming behaviour, by avoiding responses to inappropriate stimuli, by selecting favourable microhabitats and probably by avoiding predation; (3) finding and invading particular host types by selecting microhabitats frequented by the hosts and responding to sequences of specific stimuli emanating from the hosts.
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Affiliation(s)
- W Haas
- Institut für Zoologie I, Universität Erlangen-Nürnberg, Germany
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20
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Adamson ML, Caira JN. Evolutionary factors influencing the nature of parasite specificity. Parasitology 1994; 109 Suppl:S85-95. [PMID: 7854854 DOI: 10.1017/s0031182000085103] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This article considers how specificity patterns are shaped during the course of parasite evolution. Parasites are first and foremost specific to site, or microhabitat; host ranges are far more subject to change than is microhabitat. Specificity results from a number of convergent phenomena starting with habits (microhabitat and feeding styles) of free-living progenitors and the way in which the parasitic association arises (e.g., passive oral contamination as opposed to intrusive entry). These bias the types of interaction parasites have with the host, and, through this, the way specificity develops. Host ecology acts as an external factor affecting specificity and predominates in parasites that interact minimally with the hosts physiological and immune systems. Coevolutionary factors are more important in parasites that feed on host tissues or occur in extraintestinal sites. Here, parasites must present the right cues, and respond appropriately to the host defense system. The ability to generalize these cues and responses across host boundaries may act as a constraint on host range. The functional role of the host in the parasite life history also affects the degree of specificity; thus, parasites may act as host generalists in hosts that act as trophic channels to the final host. The role of competition in determining specificity is difficult to assess. However, competition has been reported to influence microhabitat and host distribution through interactive site selection and/or competitive seclusion.
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Affiliation(s)
- M L Adamson
- Department of Zoology, University of British Columbia, Vancouver, Canada
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21
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A light and electron microscope study on in vitro excystation of Microphallus abortivus (Digenea: Microphallidae) metacercariae. Parasitol Res 1991; 77:82-5. [PMID: 1994373 DOI: 10.1007/bf00934391] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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22
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Affiliation(s)
- J E Huffman
- Department of Biological Sciences, East Stroudsburg University, Pennsylvania 18301
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23
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A study of metacercarial excystment inParapronocephalum symmetricum (Trematoda: Notocotylidae). Parasitol Res 1989. [DOI: 10.1007/bf00931071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Blackler SJ, Sommerville RI. Carbonic acid and the excystment of Naegleria gruberi (Heterolobosea: Vahlkampfiidae). Int J Parasitol 1988; 18:785-91. [PMID: 3142819 DOI: 10.1016/0020-7519(88)90120-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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