Assessment of the in vitro acaricidal activity of Bravecto® (fluralaner) and a proposed orange oil-based formulation vehicle for the treatment of Sarcoptes scabiei.

BACKGROUND: Sarcoptic mange is a serious animal welfare concern in bare-nosed wombats (Vombatus ursinus). Fluralaner (Bravecto®) is a novel acaricide that has recently been utilised for treating mange in wombats. The topical 'spot-on' formulation of fluralaner can limit treatment delivery options in situ, but dilution to a volume for 'pour-on' delivery is one practicable solution. This study investigated the in vitro acaricidal activity of Bravecto, a proposed essential oil-based diluent (Orange Power®), and two of its active constituents, limonene and citral, against Sarcoptes scabiei. METHODS: Sarcoptes scabiei were sourced from experimentally infested pigs. In vitro assays were performed to determine the lethal concentration (LC50) and survival time of the mites when exposed to varying concentrations of the test solutions. RESULTS: All compounds were highly effective at killing mites in vitro. The LC50 values of Bravecto, Orange Power, limonene and citral at 1 h were 14.61 mg/ml, 4.50%, 26.53% and 0.76%, respectively. The median survival times of mites exposed to undiluted Bravecto, Orange Power and their combination were 15, 5 and 10 min, respectively. A pilot survival assay of mites collected from a mange-affected wombat showed survival times of < 10 min when exposed to Bravecto and Orange Power and 20 min when exposed to moxidectin. CONCLUSIONS: These results confirm the acaricidal properties of Bravecto, demonstrate acaricidal properties of Orange Power and support the potential suitability of Orange Power and its active constituents as a diluent for Bravecto. As well as killing mites via direct exposure, Orange Power could potentially enhance the topical delivery of Bravecto to wombats by increasing drug penetration in hyperkeratotic crusts. Further research evaluating the physiochemical properties and modes of action of Orange Power and its constituents as a formulation vehicle would be of value.

Integrating In Vitro and In Silico Approaches to Assess Monotheca buxifolia Plant Extract against Rhipicephalus (Boophilus) microplus and Sarcoptes scabiei.

Tick and mite infestations pose significant challenges to animal health, agriculture, and public health worldwide. The search for effective and environmentally friendly acaricidal agents has led researchers to explore natural alternatives. In this study, we investigated the acaricidal potential of the Monotheca buxifolia plant extract against Rhipicephalus microplus ticks and Sarcoptes scabiei mites. Additionally, we employed a computational approach to identify phytochemicals from the extract that could serve as drug candidates against these ectoparasites. The contact bioassay results demonstrated that the M. buxifolia plant extract exhibited significant efficacy against R. microplus and S. scabiei, with higher concentrations outperforming the positive control acaricide permethrin in terms of mite mortality. Time exposure to the extract also showed a positive correlation with better lethal concentration (LC50 and LC90) values. Similarly, the adult immersion test revealed a notable inhibition of tick oviposition via the plant extract, especially at higher concentrations. The two-protein primary structure, secondary structure and stability were predicted using the Expasy's ProtParam server, SOPMA and SUSUI server, respectively. Using Homology modeling, the 3D structure of the protein was obtained and validated through the ERRAT server, and active sites were determined through the CASTp server. The docking analysis revealed that Alpha-Amyrenyl acetate and alpha-Tocopherol exhibited the highest docking scores for S. scabiei and R. microplus aspartic protease proteins, respectively. These phytochemicals demonstrated strong binding interactions, suggesting their potential as acaricidal drug candidates. In conclusion, the M. buxifolia plant extract displayed significant acaricidal activity against R. microplus and S. scabiei. Moreover, the computational approach identified promising phytochemicals that could serve as potential drug candidates for controlling these ectoparasites.

A New Herbal Medicine Formulation with Potential Anti-scabies Properties to Treat Demodex and Sarcoptes Parasites.

Scabies is considered an external parasite notorious for its high prevalence causing severe and contagious skin lesions in humans and animals worldwide. This study has introduced a medicine to treat dogs infested with scabies (variants of Demodex, Sarcoptes, Psoroptes, Otodectes, etc.). The present study offers a no-side-effect herbal formulation to treat dogs infested with scabies. Unlike oral and injectable medicines, which take the form of an ointment and are topically applied on-site, this medicinal formulation can be easily used without concerns over its side effects or consumption dosages. This medicinal formulation requires no skin rinsing due to its herbal and high skin absorption properties, as recovery may take less than a month with a maximum of two times of application. To carry out the experiment, 25 sick dogs with various breeds and ages suspected of scabies were gathered. Following accurate morphological examinations of all the samples, a deep skin chip of the lesion site was provided, which was examined by a microscope. Then, 13 dogs (Mix, Terrier, Pug, Husky, Spitz) were infested with Demodex scabies and 12 dogs (Pittbull, Mix, Shih Tzu, Terrier, Boxer, Setter) with Sarcoptic scabies. The prepared product was topically administered at a constant 2% dosage to the bodies of all the samples. To prepare the ointment, 1 g of Borax (Na2B4O7·10H2O) was first dissolved in 35 g deionized water and heated to 70°C. Then, 45 g of liquid paraffin (CnH2n+2) was mixed with 1 g of Carvacrol (C10H14O) and 1 g of geranium (C10H18O) and stirred well to become a phase. Later, 17 g of the melted beeswax (C15H31COOC30H61) was added to the liquid paraffin compound. In the end, the aqueous phase was added to the oil phase, and the mixture process immediately began in one direction with a glass stirrer and continued until the product cooled down. Essential oils (EO) was obtained by steam distillation of fresh Thyme and Rose-Acented Geranium in a stainless steel distillation apparatus (alembic) for 3 h. The main components of the essential oils used in the formulation were performed using a Hewlett-Packard GC system interfaced with a mass spectrometer equipped with an HP5-MS capillary column (30 m, 0.32 mm, 0.25 µm film thicknesses). For GC-MS detection, electron ionization with ionization energy of 70 eV was used. To examine the presence of scabies, weekly skin sampling was performed, and the treatment continued until 30 days, when no skin chip of the scabies was noted. The findings revealed that the formulation developed no side effects and removed the daily use, as it could be administered once or twice a week. Also, complete recovery of scabies in all the breeds was found to be less than a month at most. This medicinal formulationcan be easily used without concerns over its side effects or consumption dosages. This study introduced a herbal formulation with effective herbal ingredients without any side effects to treat the sarcoptes and demodex parasites; unlike other chemical compounds, this medicinal formulation has no side effects, while some other formulations could develop side effects.

Essential Oils against Sarcoptes scabiei.

Herbal remedia are widely employed in folk medicine, and have been more and more often studied and considered in the treatment of several infections. Sarcoptic mange (scabies, when referring to human patients) is a highly contagious skin disease caused by Sarcoptes scabiei (sarcoptiformes, Sarcoptinae), an astigmatid mite which burrows into the epidermis, actively penetrating the stratum corneum. This parasitosis negatively affects livestock productions and represents a constraint on animal and human health. The treatment relies on permethrine and ivermectine but, since these molecules do not have ovicidal action, more than a single dose should be administered. Toxicity, the possible onset of parasite resistance, the presence of residues in meat and other animal products and environmental contamination are the major constraints. These shortcomings could be reduced by the use of plant extracts that have been in vitro or in vivo checked against these mites, sometimes with promising results. The aim of the present study was to review the literature dealing with the treatment of both scabies and sarcoptic mange by plant-derived agents, notably essential oils.

Adjunctive Agent for Treating Scabies: In vitro Killing Activity of Permethrin and Tea Tree Oil on Sarcoptes scabiei Collected from Patients

Objective: Recently, there has been a serious increase in cases of scabies. The number of patients who do not benefit from the current treatment agents is also quite high. There are publications showing that scabies mites are permethrin-resistant and ivermectin. The treatment with scabicides usually lasts for several hours and usually the treatment is repeated for at least another time, which reduces the patient's compliance with the treatment, especially in pediatric patients where the toxic effects of the products are more pronounced. Therefore there is a need for treatment modalities that are less toxic to humans. To observe the in vitro effect of tea tree oil (TTO) on S. scabiei and to compare it with those of permethrin. Methods: Scabies specimens were removed from the patient and examined using a digital microscope. Parasites that were not damaged during sampling, and showed full motion were included in the study. No treatment was applied to the patients before removal of the mites. A total of 40 parasites were included in the study, with 10 parasites in each group. Immersion oil was applied to the control group, 5% permethrin to the first treatment group, while 5% and 25% TTO were used for the second and third study groups. Results: The mean survival time (ST) of scabies mites in the 5% permethrin group was 350±31.3 min, while this for 5% TTO group 180±15.1 min and 120±13.3 min in the 25% TTO group. The mean ST of the sarcoptes in the control group was 2.820±90 min. The mean ST between the control, permethrin and TTO groups was statistically significant (p=0.03). ST between 5% and 25% TTO groups was also statistically significant (p=0.04). There were no statistical differences between permethrin and 5% or 25% TTO. Conclusion: TTO has an acaricidal effect on S. scabiei. Although not used as the treatment of choise, it can be used as a supportive agent. Since it shows an acaricidal effect within a short time, it could be used as a shampoo or shower gel to enhance the acaricidal activity of another scabicide.

Structure-based in silico design and in vitro acaricidal activity assessment of Acacia nilotica and Psidium guajava extracts against Sarcoptes scabiei var. cuniculi.

Infestation by Sarcoptes scabiei var. cuniculi mite causes scabies in humans and mange in animals. Alternative methods for developing environmentally friendly and effective plant-based acaricides are now a priority. The purpose of this research was the in silico design and in vitro evaluation of the efficacy of ethanol extracts of Acacia nilotica and Psidium guajava plant leaves against S. scabiei. Chem-Draw ultra-software (v. 12.0.2.1076.2010) was used to draw 36 distinct compounds from these plants that were employed as ligands in docking tests against S. scabiei Aspartic protease (SsAP). With docking scores of - 6.50993 and - 6.16359, respectively, clionasterol (PubChem CID 457801) and mangiferin (PubChem CID 5281647) from A. nilotica inhibited the targeted protein SsAP, while only beta-sitosterol (PubChem CID 222284) from P. guajava interacted with the SsAP active site with a docking score of - 6.20532. Mortality in contact bioassay at concentrations of 0.25, 0.5, 1.0, and 2.0 g/ml was determined to calculate median lethal time (LT50) and median lethal concentration (LC50) values. Acacia nilotica extract had an LC50 value of 0.218 g/ml compared to P. guajava extract, which had an LC50 value of 0.829 g/ml at 6 h. These results suggest that A. nilotica extract is more effective in killing mites, and these plants may have novel acaricidal properties against S. scabiei. Further research should focus on A. nilotica as a potential substitute for clinically available acaricides against resistant mites.

In vitro efficacy of essential oils against Sarcoptes scabiei.

The mite Sarcoptes scabiei is responsible for scabies, a pruritic and contagious skin disease in humans. S. scabiei is also responsible for mange in a wide range of animal species. The treatment of S. scabiei infection is hampered by an under-effectiveness of the few available drugs. The objective of this work was to evaluate the in vitro acaricide activity of a large number of plant essential oils (EOs) against S. scabiei. EOs were selected mainly on the basis of traditional treatments for dermatological infections in Madagascar. The sarcoptes originating from a porcine animal model were tested at concentrations ranging from 10 to 0.1%. The viability of sarcoptes was assessed by stereomicroscopic observation at 5 min, 15 min, 30 min, 45 min and then every hour until 6 h after treatment. Estimates of lethal time and lethal concentration producing 50% mortality were generated using a probit analysis. The survival curves were estimated using the Kaplan Meier method. A total of 31 EOs from different plants were tested. Cinnamomum zeylanicum (cinnamom) and Ocimum sanctum (tulsi) oils were the most active for all concentrations tested. They may be included in in vivo studies, in order to further assess their potential interest as topical treatments.

Activity of terpenes derived from essential oils against Sarcoptes scabiei eggs.

BACKGROUND: The limited ovicidal activity of currently available acaricides is a significant obstacle to efficacious scabies treatment. Several essential oils or their respective components have proved to be active against the eggs of arthropods, mainly lice and ticks. Information on the activity of these oils and/or components against the eggs of mites remains very limited. The aim of this study was to assess the activity of six terpenes (carvacrol, eugenol, geraniol, citral, terpinen-4-ol and linalool) commonly found in essential oils against the eggs of Sarcoptes scabiei. METHODS: Sarcoptes eggs were exposed to paraffin oil containing 1, 2.5, or 5% of each terpene tested. After a 12-h exposure period, the eggs were washed and placed in paraffin oil for hatching. Embryonic development following treatment was assessed every day to determine the stage of developmental arrest. RESULTS: The median effective concentration to obtain 50% egg mortality (EC50) was 0.5, 0.9, 2.0, 4.8, 5.1 and 9.8% for carvacrol, eugenol, geraniol, citral, terpinen-4-ol and linalool, respectively. The microscopic images of eggs after each treatment indicated that these six terpenes may act by penetrating through the aeropyles on the egg surface. CONCLUSIONS: In conclusion, carvacrol, eugenol and geraniol possess significant ovicidal activities, which should be considered as promising ovicidal agents for the treatment of scabies.

Efficacy of neem (Azadirachta indica) aqueous fruit extracts against Sarcoptes scabiei var. suis in grower pigs.

The acaricidal activity of Azadirachta indica (neem) aqueous fruit extracts was evaluated against Sarcoptes scabiei var. suis (mange mites) in an on-farm trial using grower pigs. Aqueous neem fruit extracts of three concentrations 5%, 10%, and 25% w/v and a commercial acaricide, 12.5% amitraz-based Triatix spray (positive control), were compared with pigs that received no treatment (negative control). Thirty grower pigs of the Dalland breed were allocated to the five treatments in a completely randomized experiment. Each experimental animal was sprayed on day 0 and again on day 7. Counts of mange mites, scoring of lesion index, and calculation of rubbing index were done weekly. Topical application of 25% aqueous neem fruit extract had a higher efficacy ratio (p < 0.05) than the other fruit extract concentrations, and performed similarly to an amitraz-based acaricide, suggesting a dose-dependent response. Amitraz (positive control) cured clinical mange on grower pigs after 5 weeks and 25% aqueous neem fruit extract 6 weeks post-treatment. The results indicated that aqueous neem fruit extracts have acaricidal effects against mange mites and can provide a cheaper, safer, and more eco-friendly alternative for the control of Sarcoptes mange in pigs.

Lemongrass (Cymbopogon citratus) oil: A promising miticidal and ovicidal agent against Sarcoptes scabiei.

BACKGROUND: Essential oils may represent an alternative strategy for controlling scabies, a neglected tropical disease caused by the infestation of mite from the species Sarcoptes scabiei. Lemongrass (Cymbopogen citratus) oil is reported to possess pharmacological properties including antiparasitc, antioxidant, antimicrobial and anti-inflammatory. The aim of the present study was to assess the potential efficacy of lemongrass oil against the mites and eggs of Sarcoptes scabiei. METHODOLOGY/PRINCIPAL FINDINGS: Mass spectrometry analysis confirmed that the main component presented in lemongrass oil was citral. Lemongrass oil at concentrations of 10% and 5% killed all Sarcoptes mites within 10 and 25 min, respectively. The median lethal concentration value was 1.37%, 1.08%, 0.91%, 0.64%, and 0.48% at 1, 3, 6, 12, and 24 h, respectively. Lemongrass oil at all concentrations (10%, 5%, 1%, 0.5%, 0.1%) was able to significantly decrease the hatching rate of Sarcoptes eggs. CONCLUSIONS/SIGNIFICANCE: Lemongrass oil should be considered as a promising miticidal and ovicidal agent for scabies control.

Therapeutic potential of medicinal plants for the management of scabies.

Sarcoptes scabiei (S. scabiei), a parasite mite which causes scabies disease resulting in serious public health concern. The long-term scabies disease can lead to complications such as septicemia, acute post-streptococcal glomerulonephritis, heart disease, and secondary infections. Timely treatment to the affected patients is required to control the disease and get rid of the causative agent. Delayed diagnosis and inappropriate treatment can lead to serious consequences. The most common treatment strategy is the use of allopathic medicines which can immediately relieve the patient but have the drawback of side effects. The safe and cost-effective alternative treatment strategy is the use of medicinal plants which have beneficial therapeutic potential against variety of diseases due to the presence of many bioactive phytoconstituents with no or minimal side effects. For the present review, the published articles describing scabies disease and its phytotherapeutic modalities were searched through different data bases including Google Scholar, PubMed, Medline, and ScienceDirect using the keywords like S. scabiei, prevalence of scabies disease, and phytotherapy of scabies. A large number of medicinal plants, such as Melaleuca alternifolia, Curcuma longa, Azadirachta indica, Rosmarinus officinalis, Capsicum annuum, Cinnamomum camphor, Solanum nigrum, and Eupatorium perfoliatum, have been reviewed for the promising future treatments of scabies. All the studied plants have many bioactive compounds with potential therapeutic effects against scabies and can be utilized for therapeutic purposes for this disease. This literature study has limitations because of the lack of sufficient data due to limited pre-clinical trials in this particular area. This review provides a baseline to explore the therapeutic potential of these medicinal plants against skin diseases. However, extensive studies are required to identify, authenticate, and characterize the bioactive compounds present in these plants which may lead to value addition in pharmaceutical industries providing the cost-effective way of treatment with minimal side effects.

Acaricidal activity of ethanolic extracts of Stryphnodendron adstringens and Lafoensia pacari and oil resins from Copaifera sp. and Pterodon emarginatus against Sarcoptes scabiei var. suis / Atividade acaricida dos extratos etanólicos de Stryphnodendron adstringens Mart. e Lafoensia pacari A. St Hil., bem como das óleo-resinas de Copaifera sp. e Pterodon emarginatus Vogel, 1837 contra Sarcoptes scabiei var. suis

In vitro bioassay using Sarcoptes scabiei as a test microorganism is a viable method of study for diverse drugs with acaricidal properties. A great amount of assays proves the diverse and efficient biological activity of extracts and compounds from Brazilian savanna plants. This study had as main object, test and compare the acaricidal activity of four Brazilian Cerrado bioproducts: Stryphnodendron adstringens Mart., Copaifera sp., Lafoensia pacari A. St Hil. and Pterodon emarginatus Vogel, 1837. To perform this test S. scabiei mites were collected from crusts removed on ears of highly infected sows. The mites were selected and separated in Petri dishes with three different concentrations (25, 50 and 75%) of each bioproduct, to evaluate their potential acaricidal activity. The mortality of the mites was counted in each Petri dish every hour, during five hours. The statistical analyses demonstrated differences between the bioproducts tested. The oleoresin of Copaifera sp. and P. emarginatus presented the best results with 100% of mites mortality after treatment. The ethanolic extracts of S. adstringens and L. pacari demonstrated lower acaricidal activity when compared to the oleoresins, with little or no difference among the control groups tested. This bioassay demonstrated to be efficient, reliable, low cost and easy accomplishment. Oil resins from Copaifera sp. and P. emarginatus have in vitro acaricidal activity against adult females of S. scabiei var. suis.(AU)

O uso de Sarcoptes scabiei como microrganismo teste para bioensaio in vitro é um método de estudo viável para diversas drogas acaricidas. Muitos ensaios comprovam a diversidade e eficiência de atividade biocida de extratos e componentes presentes em plantas do cerrado brasileiro. Este trabalho objetivou testar e comparar a atividade acaricida de quatro bioprodutos do cerrado brasileiro: Stryphnodendron adstringens Mart., Lafoensia pacari A. St Hil., Copaifera sp. e Pterodon emarginatus Vogel, 1837. Para este estudo, ácaros S. scabiei foram colhidos em crostas removidas de orelhas de fêmeas suínas altamente infestadas. Os ácaros foram selecionados, separados e colocados em placas de Petri com três diferentes concentrações (25, 50 e 75%) de bioprodutos, para avaliar o potencial de atividade acaricida de cada um. Foi realizada a contagem da mortalidade dos ácaros em cada placa de Petri a cada hora, durante cinco horas. As análises estatísticas demonstraram diferenças entre os bioprodutos testados. As óleo-resinas de Copaifera sp. e P. emarginatus apresentaram os melhores resultados, com 100% de mortalidade dos ácaros após tratamento. Os extratos etanólicos de S. adstringens Mart. e L. pacari demonstraram menor atividade acaricida quando comparados as óleo-resinas, com pequena ou nenhuma diferença entre os resultados dos grupos controle. Este ensaio demonstrou ser uma ferramenta eficiente, confiável, de baixo custo e de fácil realização. As óleo-resinas Copaifera sp. e P. emarginatus possuem atividade acaricida in vitro sobre fêmeas adultas de S. scabiei var. suis.(AU)

Norwegian scabies in a patient treated with Tripterygium glycoside for rheumatoid arthritis.

We report an 80-year-old male patient with severe rheumatoid arthritis who was treated with tripterygium glycoside, an immunosuppressive agent made from the extract of a Chinese medicinal herb called Tripterygium wilfordii Hook F. The patient had no apparent skin lesions before the treatment, but he developed aggressive hyperkeratotic lesions with rapid progression after using tripterygium glycoside. He was repeatedly diagnosed with eczema, but treatment failed to achieve efficacy. Interestingly, a microscopic examination of the lesions revealed numerous scabies mites and eggs. Thus, we confirmed the diagnosis of Norwegian scabies infection. Treated with crotamiton 10% cream and 10% sulfur ointment for one month, the patient's clinical symptoms disappeared.

Norwegian scabies in a patient treated with Tripterygium glycoside for rheumatoid arthritis

Abstract: We report an 80-year-old male patient with severe rheumatoid arthritis who was treated with tripterygium glycoside, an immunosuppressive agent made from the extract of a Chinese medicinal herb called Tripterygium wilfordii Hook F. The patient had no apparent skin lesions before the treatment, but he developed aggressive hyperkeratotic lesions with rapid progression after using tripterygium glycoside. He was repeatedly diagnosed with eczema, but treatment failed to achieve efficacy. Interestingly, a microscopic examination of the lesions revealed numerous scabies mites and eggs. Thus, we confirmed the diagnosis of Norwegian scabies infection. Treated with crotamiton 10% cream and 10% sulfur ointment for one month, the patient's clinical symptoms disappeared.

Increase the risk of intellectual disability in children with scabies: A nationwide population-based cohort study.

Scabies is a common and distressing disease caused by the mite Sarcoptes scabiei var. hominis. Psychiatric disorder in childhood is an important disease and easily neglected. There are several similarities in scabies and psychiatric disorders in childhood (PDC). Both of them may present with pruritus. They are relatively common in patients with lower socioeconomic status and crowded environment. Furthermore, immune-mediated inflammatory processes play a role in the pathophysiology in both diseases. An association between scabies and psychiatric disorders may exist. This nationwide population-based cohort study utilized data from the National Health Insurance Research Database to investigate the relationship between scabies and PDC. A total of 2137 children with scabies were identified as the study group and 8548 age- and sex-matched children were selected as the control group. A total of 607 (5.68%) children developed PDC during the 7-year follow-up period. The overall incidences of PDC are similar but patients with scabies had a higher risk of developing intellectual disability (ID) (scabies group vs control group: 1.3% vs 0.6%, adjusted hazard ratio: 2.04 and 95% confidence interval: 1.25-3.32). The immune-mediated inflammatory processes of both diseases were reviewed and may contribute to the 104% increased risk of interleukin in patients with scabies. We suggest a more comprehensive management in treating patients with scabies or ID. Early and comprehensive treatment of scabies and other risk factors may decrease the risk of subsequent ID. When we approach patients with ID, concurrent evaluation of scabies and other risk factors may contribute to successful management.

In vitro activity of ten essential oils against Sarcoptes scabiei.

BACKGROUND: The development of alternative approaches in ectoparasite management is currently required. Essential oils have been demonstrated to exhibit fumigant and topical toxicity to a number of arthropods. The aim of the present study was to assess the potential efficacy of ten essential oils against Sarcoptes scabiei. METHODS: The major chemical components of the oils were identified by GC-MS analysis. Contact and fumigation bioassays were performed on Sarcoptes mites collected from experimentally infected pigs. For contact bioassays, essential oils were diluted with paraffin to get concentrations at 10, 5, and even 1% for the most efficient ones. The mites were inspected under a stereomicroscope 10, 20, 30, 40, 50, 60, 90, 120, 150, and 180min after contact. For fumigation bioassay, a filter paper was treated with 100 µL of the pure essential oil. The mites were inspected under a stereomicroscope for the first 5min, and then every 5min until 1h. RESULTS: Using contact bioassays, 1% clove and palmarosa oil killed all the mites within 20 and 50min, respectively. The oils efficacy order was: clove > palmarosa > geranium > tea tree > lavender > manuka > bitter orange > eucalyptus > Japanese cedar. In fumigation bioassays, the efficacy order was: tea tree > clove > eucalyptus > lavender > palmarosa > geranium > Japanese cedar > bitter orange > manuka. In both bioassays, cade oil showed no activity. CONCLUSION: Essential oils, especially tea tree, clove, palmarosa, and eucalyptus oils, are potential complementary or alternative products to treat S. scabiei infections in humans or animals, as well as to control the mites in the environment.

Preclinical Study of Single-Dose Moxidectin, a New Oral Treatment for Scabies: Efficacy, Safety, and Pharmacokinetics Compared to Two-Dose Ivermectin in a Porcine Model.

BACKGROUND: Scabies is one of the commonest dermatological conditions globally; however it is a largely underexplored and truly neglected infectious disease. Foremost, improvement in the management of this public health burden is imperative. Current treatments with topical agents and/or oral ivermectin (IVM) are insufficient and drug resistance is emerging. Moxidectin (MOX), with more advantageous pharmacological profiles may be a promising alternative. METHODOLOGY/PRINCIPAL FINDINGS: Using a porcine scabies model, 12 pigs were randomly assigned to receive orally either MOX (0.3 mg/kg once), IVM (0.2 mg/kg twice) or no treatment. We evaluated treatment efficacies by assessing mite count, clinical lesions, pruritus and ELISA-determined anti-S. scabiei IgG antibodies reductions. Plasma and skin pharmacokinetic profiles were determined. At day 14 post-treatment, all four MOX-treated but only two IVM-treated pigs were mite-free. MOX efficacy was 100% and remained unchanged until study-end (D47), compared to 62% (range 26-100%) for IVM, with one IVM-treated pig remaining infected until D47. Clinical scabies lesions, pruritus and anti-S. scabiei IgG antibodies had completely disappeared in all MOX-treated but only 75% of IVM-treated pigs. MOX persisted ~9 times longer than IVM in plasma and skin, thereby covering the mite's entire life cycle and enabling long-lasting efficacy. CONCLUSIONS/SIGNIFICANCE: Our data demonstrate that oral single-dose MOX was more effective than two consecutive IVM-doses, supporting MOX as potential therapeutic approach for scabies.

In vitro and in vivo effect of Citrus limon essential oil against sarcoptic mange in rabbits.

The effect of lemon oil (Citrus limon) on Sarcoptes scabiei var. cuniculi was evaluated in vitro and in vivo. The mite samples were collected from naturally infected rabbits. The lemon oil was prepared in six concentrations by dilution with distilled water (2.5, 5, 10, 20, 50, and 100 %). In vitro application was done in five replicates for each concentration in petri dishes in the laboratory. The treated mites were observed at 1, 12, and 24 h post application (PA) for lemon oil effect. In addition, oxidative stress profile was evaluated for the treated mite. Dependent on in vitro results, 20 % lemon oil was used in vivo trial. Twenty-four naturally infected rabbits were divided into three groups of eight: 20 % lemon oil, deltamethrin, and untreated control. The infected parts of rabbits were treated topically once a week for four successive weeks. In vitro application results showed that lemon oil 10 and 20 % diluted in water caused mortality to 100 % of mites after 24 h PA. The oxidative stress profile revealed that mites treated with 20 % lemon oil had significantly (P < 0.05) higher hydrogen peroxide and malondialdehyde when compared with mites treated with deltamethrin or distilled water. In vivo application of 20 % lemon oil on naturally infected rabbits showed complete recovery from clinical signs, absence of mite in microscopic examination from the second week of treatment. In addition, productive performance was significantly better than infected untreated group. Also, the treated tissue showed stoppage of scale formation and hair growth faster than deltamethrin-treated rabbits. Consequently, lemon oil has remarkable miticidal activity in vitro and in vivo applications.

In vitro acaricidal activity of 1,8-cineole against Sarcoptes scabiei var. cuniculi and regulating effects on enzyme activity.

1,8-Cineole found in many essential oils is a monoterpene and acts as a repellent against Sarcoptes scabiei var. cuniculi. In the present study, the acaricidal activity of 1,8-cineole against S. scabiei var. cuniculi was evaluated and the acaricidal mechanism was also investigated by assaying enzyme activities. The results showed that the lethal concentration of 50% (LC50) value (95% confidence limit (CL)) and the lethal time of 50% (LT50) value (95% CL) of 1,8-cineole were 2.77 mg/mL and 3.606 h, respectively. The pathological changes under transmission electron microscopy showed that the morphology of the mitochondria was abnormal, the cell nuclear membrane was damaged, and the nuclear chromatin was dissoluted. The activities of superoxide dismutase (SOD), glutathione-s-transferases (GSTs), monoamine oxidase (MAO), nitric oxide synthase (NOS), and acetylcholinesterase (AChE) were significantly changed after treatment with 1,8-cineole for 4, 8, 12, and 24 h. SOD and GSTs are associated with the protection mechanism of scabies mites. And, the activities of SOD and GSTs were increased as compared with the control group. MAO, AChE, and NOS are associated with the nervous system of scabies mites. The activity of MAO was increased whereas the AChE was suppressed. The activity of NOS was suppressed in the high-dose group whereas increased in the middle-dose group and low-dose group. These results indicated that the mechanism of 1,8-cineole mainly attributed to the changes of these enzyme activities related to the nervous system of scabies mites.