Experimental parasitology最新文献

{"title":"Study of antiplasmodial activity, toxicity, pharmacokinetic profiles of n-methyl-isatin (CH3ISACN) derivative","authors":"Cinthia Rodrigues Melo ,&nbsp;Caliandra Maria Bezerra Luna Lima ,&nbsp;Brenna Marceliane de Melo Marcelino ,&nbsp;Claudio Gabriel Lima-Júnior ,&nbsp;Abrahão Alves de Oliveira Filho ,&nbsp;Igor Gabriel da Silva Ramalho ,&nbsp;Kardilandia Mendes de Oliveira ,&nbsp;Gabriela Tafaela Dias ,&nbsp;Giciane Carvalho Vieira ,&nbsp;Valter Ferreira de Andrade-Neto ,&nbsp;Margareth de Fátima Formiga Melo Diniz","doi":"10.1016/j.exppara.2025.108910","DOIUrl":"10.1016/j.exppara.2025.108910","url":null,"abstract":"<div><div>One of the main factors that have made it difficult to control malaria is the large number of parasites that are resistant to the usual antimalarial drugs. Therefore, the development of new drugs that are more effective and with low toxicity for humans is necessary. In this work, we evaluated the adduct 2-(3-hydroxy-1-methyl-2-oxoindolin-3-yl)acrylonitrile, also called CH₃ISACN, as a potential antimalarial through <em>in vitro</em> studies, and evaluated its effects <em>in silico</em> and <em>in vivo</em> toxicology. For this, the compound CH₃ISACN was exposed to <em>P. falciparum</em> W2 strain in infected human erythrocytes. The results showed that the CH₃ISACN adduct showed good antiplasmodial activity, moderate cytotoxicity, and good cell viability. In addition, it has been shown to have good theoretical oral bioavailability and did not pose a risk of toxicity in <em>in-silico</em> studies. Through the <em>in vivo</em> study, acute toxicity was evaluated, in which doses of 300 mg/kg and 2000 mg/kg of the test substance were administered to adult female <em>Wistar</em> rats. CH₃ISACN did not cause death in any of the animals, thus presenting a high LD₅₀ and therefore low toxicity. There was no behavioral change in the animals, as well as in the other parameters evaluated; the highest dose tested did not cause any significant change. Only a reduction in urea concentration, but that did not bring relevant clinical significance. Through the histological study, no changes were found that would indicate intoxication in the organs of the animals. Finally, the CH₃ISACN adduct presents itself as a promising drug candidate for the treatment of malaria.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"270 ","pages":"Article 108910"},"PeriodicalIF":1.4,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143064488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro and in vivo leishmanicidal and trypanocidal activities of isoflavans from Tabebuia chrysantha (Jacq.) G. Nicholson timber by-products","authors":"Edwin Correa ,&nbsp;Sara M. Robledo ,&nbsp;Fernando Echeverri ,&nbsp;Wiston Quiñones ,&nbsp;Natalia Arbeláez ,&nbsp;Javier Murillo ,&nbsp;Tatiana Pineda ,&nbsp;Fernando Torres","doi":"10.1016/j.exppara.2025.108899","DOIUrl":"10.1016/j.exppara.2025.108899","url":null,"abstract":"<div><div>Cutaneous Leishmaniasis and Chagas disease are neglected tropical diseases that affect millions worldwide. Despite the high morbidity associated with these infections, current treatments are often highly toxic and are showing diminishing efficacy. Thus, new therapeutic options are urgently needed. In this study, bio-guided assays were conducted on the sawdust of <em>Tabebuia chrysantha</em> (\"guayacán\") to identify promising bioactive compounds. The ethanolic crude extract, five chromatography fractions, pure isoflavans sativan and vestitol, and a mixture were evaluated in vitro against <em>Leishmania braziliensis</em> and <em>Trypanosoma cruzi</em>. High leishmanicidal and trypanocidal activities were observed in the crude extract, fraction F2 (rich in sativan and vestitol), and the two pure isoflavans. Given the abundance and ease of obtaining the isoflavan mixture, its therapeutic potential was further evaluated <em>in vivo</em> in hamsters infected with <em>L. braziliensis</em> and mice infected with <em>T. cruzi</em>. Remarkably, topical and intraperitoneal administration of the chromatography fraction achieved a 67% clinical cure in hamsters with <em>L. braziliensis</em> infection and a 75% reduction in parasitemia in <em>T. cruzi</em>-infected mice. While the antiparasitic effects of certain flavonoids have been documented, this study is the first to demonstrate the efficacy of isoflavans in animal models for both diseases. The potential efficacy observed against <em>T. cruzi</em> and <em>L. braziliensis</em>, two pathogens with limited treatment options and a significant drawback of the available treatments, highlights the therapeutic potential of this combination of sativan and vestitol, which can be derived from timber industry waste, presenting an abundant and accessible source for further development.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"270 ","pages":"Article 108899"},"PeriodicalIF":1.4,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143036843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antileishmanial activity of hesperetin on Leishmania donovani, in vitro and in silico inhibition of acetylcholinesterase and investigation of the targets sterol C-24 reductase and N-myristoyltransferase","authors":"Saiaka Ingrid Parente Rocha ,&nbsp;Victor Borges Fernandes ,&nbsp;Wildson Max Barbosa da Silva ,&nbsp;Lucas Soares Frota ,&nbsp;Andreza Raposo Garcia ,&nbsp;Flora Fernanda Schulze Spíndola ,&nbsp;Caio Henrique Alexandre Roberto ,&nbsp;Vanessa Maria Rodrigues de Souza ,&nbsp;Klinger Antonio da Franca Rodrigues ,&nbsp;Igor de Almeida Rodrigues ,&nbsp;Emmanuel Silva Marinho ,&nbsp;Márcia Machado Marinho ,&nbsp;Nadja Soares Vila-Nova ,&nbsp;Selene Maia de Morais","doi":"10.1016/j.exppara.2025.108903","DOIUrl":"10.1016/j.exppara.2025.108903","url":null,"abstract":"<div><div>The current treatment of leishmaniasis is confronted with significant challenges, including limited efficacy, adverse effects, and parasite resistance to drugs. The search for alternative therapeutic options, including the utilisation of natural products, has demonstrated considerable promise. In this study, the antileishmanial activity of the flavonoid hesperetin against <em>Leishmania donovani</em>, the causative agent of visceral leishmaniasis, was reported for the first time. Hesperetin was obtained through the hydrolysis of hesperidin and subsequently subjected to chemical characterisation via Infrared and NMR spectroscopy. The antileishmanial activity and cytotoxicity against RAW 264.7 macrophages were evaluated using the MTT colorimetric assay. In order to investigate the potential mechanisms of action, <em>in vitro</em> acetylcholinesterase inhibition assays and molecular docking analyses were conducted. Hesperetin showed an antipromastigote effect (IC₅₀: 62.89 μM) with no evidence of cytotoxicity (CC₅₀: 612.8 μM), with a selectivity index (SI) of 9.74, being 5.4 times more effective than trivalent antimony. In comparison, antimony showed an IC₅₀ of 80.16 μM, a CC₅₀ of 145.04 μM and a SI of 1.8, indicating a limited safety margin. The compound was observed to inhibit acetylcholinesterase (IC₅₀ of 18.44 μg/mL), present in mitochondrial and plasma membrane of the parasite. Molecular docking and dynamic simulations indicated that hesperetin inhibit sterol C-24 reductase, essential for ergosterol biosynthesis and membrane integrity of <em>L. donovani</em> and shows activity against N-myristoyl transferase, responsible for parasite proliferation cycle. These findings open promising avenues for the development of effective antileishmanial therapies.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"270 ","pages":"Article 108903"},"PeriodicalIF":1.4,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143002784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular host-parasite interaction at the site of vector bite","authors":"Eman Attia Elmorsy","doi":"10.1016/j.exppara.2025.108902","DOIUrl":"10.1016/j.exppara.2025.108902","url":null,"abstract":"","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"270 ","pages":"Article 108902"},"PeriodicalIF":1.4,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143002785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Fimbrin TvFim1, an immunogenic protein involved in male trichomoniasis","authors":"Laura Isabel Vázquez-Carrillo ,&nbsp;Jonathan Puente-Rivera ,&nbsp;Julio Cesar Torres-Romero ,&nbsp;Laura Itzel Quintas-Granados ,&nbsp;María Elizbeth Alvarez-Sánchez","doi":"10.1016/j.exppara.2024.108867","DOIUrl":"10.1016/j.exppara.2024.108867","url":null,"abstract":"<div><div>An active immunoproteome of <em>Trichomonas vaginalis</em> was obtained by 2D-Western blotting (2D-WB). Subsequent proteoform identification by mass spectrometry (MS) showed differential expression and specific immunoreactions of multiple proteins mediated by the presence of Zn²⁺. A total of 25 proteoforms were immunologically reactive, generally under Zn²⁺ conditions, and MS analysis revealed that the fimbrin (plastin) of <em>T. vaginalis</em> (TvFim1) was recognized by the sera of male patients with trichomoniasis but not by the sera of infected female patients. These findings suggest that the protein is immunogenic during active male trichomoniasis and that cytoskeletal proteins, including fimbrins, may also act as virulence factors in addition to their role in parasite morphogenesis.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"268 ","pages":"Article 108867"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142791459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antiparasitic and antioxidant effects of selenium nanoparticles on parasitic Trichinella spiralis","authors":"Yosra Adel Ebrahim Nagdy,&nbsp;Zohour Ebrahim Nabil,&nbsp;Nahla Soliman El-Shenawy,&nbsp;Elham Ali Elkhawass","doi":"10.1016/j.exppara.2024.108876","DOIUrl":"10.1016/j.exppara.2024.108876","url":null,"abstract":"<div><div>This study presents a comprehensive methodology for the synthesis, characterization, and evaluation of selenium nanoparticles (SeNPs) for their anthelmintic properties against <em>Trichinella spiralis</em>. SeNPs were synthesized via a chemical reduction method, with a color change from clear white to brownish-red indicating nanoparticle formation. X-ray diffraction (XRD) analysis revealed broad peaks at 2θ ranges of 20–33° and 48–58°, confirming the semi-crystalline nature of the nanoparticles. UV–Vis absorption spectroscopy identified a characteristic peak at around 295 nm. High-resolution transmission electron microscopy (HRTEM) showed spherical, monodispersed SeNPs with smooth surfaces, ranging from 30 to 106 nm in size, with an average diameter of 69 nm. Forty-two male rats were divided into six groups, including healthy controls and <em>T. spiralis</em>-infected rats treated with varying doses of SeNPs. Body and organ weight indexes were assessed at the start, during the intestinal and muscular phases. Significant body weight increases were observed during the intestinal phase, particularly in the positive control group. Organ weight analysis showed a significant decrease in liver weight in the high-dose SeNP group compared to controls. SeNP treatment significantly reduced the number of adult worms in the intestines and encysted larvae in muscles. The high-dose group reduced adult worms and encysted larvae more than the low-dose group. Scanning electron microscopy (SEM) revealed morphological alterations in adult <em>T. spiralis</em> worms, including wrinkled architecture, torn cuticles, and severe sloughing in high-dose treated worms. During the muscular phase, significant decreases in hemoglobin and red blood cell count were observed in the positive control group, while SeNP treatment restored these levels. Liver enzyme activities (AST, ALT, and ALP) were elevated in infected untreated groups but were enhanced with SeNP treatment. Antioxidant enzyme activities (CAT, and SOD) increased in SeNP-treated groups, with higher doses showing greater efficacy in reducing oxidative stress markers (MDA) and inflammatory markers (TNF-α, and IL-6). Histological analysis showed significant restoration of normal intestinal architecture in high-dose SeNP-treated infected rats, including the reduction of villus atrophy and leukocyte infiltration. In diaphragm muscles, high-dose SeNP treatment minimized encysted larval deposition and restored normal muscle architecture. We can conclude that the study demonstrates the potential of SeNPs as an effective anthelmintic agent against <em>T. spiralis</em>, highlighting their synthesis, characterization, and therapeutic efficacy.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"268 ","pages":"Article 108876"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142821950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antiparasitic activity of Cerastes cerastes venom on Schistosoma mansoni infected mice‏","authors":"Asmaa Mahdy,&nbsp;Osama M.S. Mostafa,&nbsp;Marwa M. Aboueldahab,&nbsp;Ahmed H. Nigm","doi":"10.1016/j.exppara.2024.108866","DOIUrl":"10.1016/j.exppara.2024.108866","url":null,"abstract":"<div><div>This study investigates whether <em>Cerastes cerastes</em> venom (CCV) administrated at different doses (3 and 6μg/mouse) and times (a week pre-infection, the first week post-infection, and the fifth week post-infection) possesses antischistosomal activity on <em>Schistosoma mansoni</em> infected mice. The results showed that treatment with half lethal dose (6 μg/mouse) of CCV, at various time schedules, led to a significant decrease in the total worm burden. However, quarter lethal dose (3μg/mouse) of CCV showed a significant decrease in the total worm burden only when administered a week pre-infection. The total number of deposited eggs by females of <em>S. mansoni</em> was significantly decreased in the liver and the intestine of mice treated with 3μg/mouse or 6μg/mouse CCV, associated with significant alterations in the oogram pattern with significant elevation in dead eggs levels and significant decrease in the number of mature eggs. Histological examinations illustrated a significant decrease in the number and diameter of hepatic granulomas in high dose (6μg/mouse) CCV-treated groups, while it was significant only a week pre-infection in low dose (3μg/mouse) CCV-treated groups. CCV also caused several tegumental changes in treated female and male worms, including loss of the normal surface architecture, tubercular destruction, loss of tubercles' spines, oedema, erosion, membrane blebbing, and swelling. <em>S. mansoni</em>-infected mice groups treated with CCV (6μg/mouse) a week before infection and at fifth week post-infection had, in all individuals up to a dilution of 1:1600, higher levels of antibodies against adult worm antigen. The current investigation found that <em>C. cerastes</em> venom has potential antischistosomal action in a time and dose-dependent manner (more enhanced antischistosomal effects at a dose of 6 μg and in the group treated in a week before infection), in addition to its potential immunomodulatory effect against schistosomiasis infection. More studies will be required to identify the venom's active ingredients that affect the host's immunology. This information could be used in the future to develop novel antischistosomal therapies.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"268 ","pages":"Article 108866"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142767519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of acute schistosomiasis mansoni and concurrent type 1 diabetes on pancreatic architecture in mice","authors":"Vanessa Coelho de Góes ,&nbsp;Luciana Brandão-Bezerra ,&nbsp;Renata Heisler Neves ,&nbsp;Albanita Viana de Oliveira ,&nbsp;José Roberto Machado-Silva","doi":"10.1016/j.exppara.2024.108885","DOIUrl":"10.1016/j.exppara.2024.108885","url":null,"abstract":"<div><div>It is not well understood how type 1 diabetes (T1D) and concomitant acute schistosomiasis mansoni affect pancreatic architecture. Male Swiss mice were administered streptozotocin (single 100 mg/kg i.p.) and thirty days later infected with 80 Schistosoma mansoni cercariae. Mice were divided into groups (<em>n</em> = 5): A (healthy control), B (infected), C (uninfected diabetic), and D (diabetic + infected) and euthanized at week 9 post-infection. Blood glucose levels, biometry, stereology, and pancreatic histology were evaluated. Groups C and D showed hyperglycemia (&gt;200 mg/dL). Group B had a higher (+79%) pancreatic mass than A. The endocrine pancreas showed fewer islets of Langerhans (−62%; −50%) and a smaller islet area (−36%; −30%) in C and D, respectively, compared to A. Group D had a smaller (−37%) islet area than B. The volume density of the islets was reduced (−33%) in group C compared to A. Within the exocrine pancreas, the volume density of the pancreatic parenchyma was reduced in groups B (−29%) and D (−26%), and increased in C (+15%) compared to A. Group D was reduced (−35%) compared to C. Group D showed generalized pancreatitis, including disrupted tissue with multiple nuclei of destroyed acinar cells and lost connective tissue and acinar cells with a paucity of zymogen granules. Pancreatic stellate cells were found around areas of distorted architecture. Paired adult worms were found within the pancreatic vessels. In conclusion, concomitant T1D and schistosomiasis mansoni promote extensive exocrine and endocrine changes in the pancreas, whereas pancreatic involvement begins in acute schistosomiasis.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"268 ","pages":"Article 108885"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142893043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular detection of Cooperia oncophora and Ostertagia ostertagi in cattle: Comparison of sample processing and detection on ddPCR and qPCR platforms","authors":"Ian David Woolsey ,&nbsp;Tonje Opsal ,&nbsp;Lucy Robertson ,&nbsp;Sokratis Ptochos ,&nbsp;Lisbeth Hektoen","doi":"10.1016/j.exppara.2024.108878","DOIUrl":"10.1016/j.exppara.2024.108878","url":null,"abstract":"<div><div>Faecal samples were obtained from 77 first season grazers from 20 Norwegian dairy herds in autumn 2020 for analysis of <em>Cooperia oncophora</em> and <em>Ostertagia ostertagi</em> infection. Strongylid eggs per gram of faeces (EPG) were determined for each sample and the samples underwent larval culture. DNA was extracted from the faeces at different stages of the culture preparation: from faecal slurry (FS), direct extraction before culture (DBC), and direct extraction after culture (DAC). Extracted DNA was subject to molecular assay for both <em>C. oncophora</em> and <em>O. ostertagi</em> using both a published ddPCR assay and a modified qPCR duplex assay targeting the ITS-2 gene. For <em>C. oncophora,</em> DBC samples contained significantly less ITS-2 copies than DAC and FS samples (<em>p</em> ≤ 0.0001 for both) for qPCR, but not between DAC and FS samples (<em>p</em> = 0.339). Droplet digital PCR with DBC samples yielded significantly fewer ITS-2 copies than DAC and FS samples (<em>p</em> ≤ 0.0001). For <em>O. ostertagi,</em> the ITS-2 copies in DBC samples differed significantly from levels in DAC and FS samples on the qPCR platform (<em>p=</em>0.002 and 0.044, respectively) as was the case with ddPCR (<em>p</em> ≤ 0.0001 and 0.0137). Overall, across the various processing techniques, <em>C. oncophora</em> results obtained on both ddPCR and qPCR platforms correlated with EPG better than was found for equivalent results for <em>O. ostertagi</em> and results are strongly indicative of poor correlation when EPG counts are low. Results from this study suggest that DAC faecal processing was of limited practical use.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"268 ","pages":"Article 108878"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142821969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of synergistic and antagonistic interactions between volatile compounds thymol, carvacrol, and eugenol diluted in solvents against Rhipicephalus microplus in in vitro tests","authors":"Leandro Rodrigues ,&nbsp;Rodrigo Giglioti ,&nbsp;Luciana Morita Katiki ,&nbsp;André Lucio Franceschini Sarria ,&nbsp;Germano Scholze ,&nbsp;Cecília José Veríssimo","doi":"10.1016/j.exppara.2024.108877","DOIUrl":"10.1016/j.exppara.2024.108877","url":null,"abstract":"<div><div>The cattle tick <em>Rhipicephalus microplus</em> is prevalent in tropical and subtropical regions, causing substantial economic losses due to its resistance to conventional acaricides. There is an urgent need to identify safe and effective new acaricidal agents. Essential oils and their volatile compounds are promising alternatives. Ensuring the use of optimal solvents or surfactants that do not compromise the acaricidal activity of these compounds during testing is crucial. This study aims to evaluate how compounds thymol, carvacrol and eugenol interact with xylol, methanol, ethanol, acetone, isopropyl alcohol, glycerol, dimethyl sulfoxide, castor oil, propylene glycol, vaseline, and Tween 80® to enhance (or to worse) their acaricidal efficacy against <em>R. microplus</em>. Larval mortality time were compared against one negative control (soybean oil) and two positive controls (commercial <em>pour-on</em> products). The experiments were conducted in 48-well polyethylene plates, with around 100 larvae immersed in 200 μl of each solvent at 100, 50, 25, 12.5, 6.25, 3.125 and 1.56% and diluted in soybean oil or water, according to solubility. Each volatile compound (Thymol, carvacrol and eugenol) was diluted in the tested solvents to assess larval mortality time. Xylol demonstrated the shortest larval mortality time, even at a minimum concentration (p &lt; 0.05). In contrast, liquid vaseline exhibited the longest larval mortality time. When thymol, carvacrol, and eugenol were combined with xylol, they achieved the shortest larval mortality time. Conversely, when diluted in liquid vaseline they exhibited synergistic effects decreasing the mortality time. Tween 80® worsen the efficacy of thymol, carvacrol, and eugenol, resulting in prolonged larval mortality times. These findings emphasize the critical role of solvent selection, indicating the choice of solvent profoundly affects the formulation's effectiveness, directly influencing the activity of the active compounds.</div></div>","PeriodicalId":12117,"journal":{"name":"Experimental parasitology","volume":"268 ","pages":"Article 108877"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142824035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}