In vitro efficacy of five essential oils against Pediculus humanus capitis.

Treatment of head lice has relied mainly on the use of topical insecticides. Today, conventional topical pediculicides have suffered considerable loss of activity worldwide. There is increasing interest in the use of natural products such as essential oils for head louse control, and many of them are now incorporated into various over-the-counter products presented as pediculicides, often without proper evaluation. The aim of the present study was to assess the in vitro efficacy of five essential oils against adults of Pediculus humanus capitis using a contact filter paper toxicity bioassay. The chemical composition of the essential oils from wild bergamot, clove, lavender, tea tree, and Yunnan verbena was analyzed by gas chromatography-mass spectrometry. All treatments and controls were replicated three times on separate occasions over a period of 11 months. In all, 1239 living lice were collected from the scalp of 51 subjects, aged from 1 to 69 years. Clove oil, diluted either in coco oil or sunflower oil, demonstrated the best adulticidal activity, reaching > 90% mortality within 2 h in lice submitted to a 30-min contact. Yunnan verbena oil diluted in coco oil showed also a significant efficacy. Other essential oils showed a lower efficacy. The oil's major component(s) differed according to the tested oils and appeared chemically diverse. In the case of clove oil, the eugenol appeared as the main component. This study confirmed the potential interest of some of the essential oils tested, but not all, as products to include possibly in a pediculicidal formulation.

Safety, Efficacy, and Physicochemical Characterization of Tinospora crispa Ointment: A Community-Based Formulation against Pediculus humanus capitis.

The high prevalence of pediculosis capitis, commonly known as head lice (Pediculus humanus capitis) infestation, has led to the preparation of a community-based pediculicidal ointment, which is made of common household items and the extract of Tinospora crispa stem. The present study aimed to evaluate the safety, efficacy, and physicochemical characteristics of the T. crispa pediculicidal ointment. The physicochemical properties of the ointment were characterized, and safety was determined using acute dermal irritation test (OECD 404), while the efficacy was assessed using an in vitro pediculicidal assay. Furthermore, the chemical compounds present in T. crispa were identified using liquid-liquid extraction followed by ultra-performance liquid chromatography quadruple time-of-flight mass spectrometric (UPLC-qTOF/MS) analysis. The community-based ointment formulation was light yellow in color, homogeneous, smooth, with distinct aromatic odor and pH of 6.92±0.09. It has spreadability value of 15.04±0.98 g·cm/sec and has thixotropic behavior. It was also found to be non-irritant, with a primary irritation index value of 0.15. Moreover, it was comparable to the pediculicidal activity of the positive control Kwell®, a commercially available 1% permethrin shampoo (P>0.05), and was significantly different to the activity of the negative control ointment, a mixture of palm oil and candle wax (P<0.05). These findings suggested that the community-based T. crispa pediculicidal ointment is safe and effective, having acceptable physicochemical characteristics. Its activity can be attributed to the presence of compounds moupinamide and physalin I.

In vitro Investigation of the Pediculicidal Activities of the Volatile Oil Components of Some Medical Plants Raised in Turkey.

OBJECTIVE: The human head louse Pediculus capitis has recently acquired resistance to commercially available insecticides, which has expanded the search concerning the pediculicidal activities of some herbal products. The present study aimed to assess the in vitro pediculicidal activities of volatile oils extracted from 10 medical plants raised in Turkey: Rosa damascena (red provins rose), Pelargonium graveolens (geranium), Lavandula angustifolia (lavender), Salvia triloba (salvia), Rosmarinus officinalis (rosemary; two different chemotypes), Citrus bergamia (citrus tree), Cymbopogon nardus (citronella), Citrus limonum (lemon), and Cymbopogon flexuosus (lemongrass). METHODS: Head lice obtained from school children in Manisa Province were initially grouped as adults and nymphs and were then kept under optimal conditions (temperature of 27°C and humidity of 50%). A pinch of hair and filter paper were placed in Petri dishes and seven adults and seven nymphs were separately put in Petri dishes. The extracts obtained from each volatile oil were dropped on the lice specimens. RESULTS: The active movement of the external (antenna and legs) and internal (midgut and intestine) organs of the lice was monitored and recorded starting from 5th min for 24 hours by 10 to 30 minutes intervals. The time of death was defined as the loss of active movement and cessation of intestinal activities of lice. The results were analyzed using Statistical Packages for the Social Sciences (SPSS) version 15. CONCLUSION: The results showed that the volatile oil of Rosmarinus officinalis (two different chemotypes) was more effective than the other oils.

The potential application of plant essential oils to control Pediculus humanus capitis (Anoplura: Pediculidae).

The human head louse, Pediculus humanus capitis (Anoplura: Pediculidae), is an ectoparasite confined to the scalp and human hairs. The repeated use of insecticides for the control of head lice during past decades has resulted in the development of marked levels of resistance. Natural compounds such as essential oils (EOs) have been suggested as alternative sources for insect control agents. In order to introduce a new pediculicide based on EOs, the effectiveness of the product and their effects on human being must be analyzed. In consequence, the biological activity of EOs from the leaves and fruits of Schinus areira (Anacardiaceae) and the leaves of Thymus vulgaris (Lamiaceae), Aloysia polystachya and Aloysia citriodora (Verbenacea) were evaluated against the eggs and adults of P. humanus capitis by fumigant and contact toxicity bioassays. Additionally, dermal corrosion/irritation tests were performed on New Zealand albino rabbits. In a fumigant bioassay, EOs from the leaves and fruits of S. areira were the most toxic against P. humanus capitis adults while these EOs and T. vulgaris were the most effective against the eggs. In contact bioassay, the EO from T. vulgaris was the most toxic against both stages. In the corrosion/irritation tests, the EOs did not produce dermal effects. According to the results, the essential oils from the leaves of T. vulgaris would be a valid tool for the management of P. humanus capitis. This EO produces a high knockdown effect in adults (followed by mortality) and toxicity in the eggs when it is applied for 21 min at a low concentration.

Common Blepharitis Related to Phthiriasis Palpebrarum: Argon Laser Phototherapy.

A 42-year-old woman was admitted to Mersin University, Department of Ophthalmology Clinic with itching and burning sensation of the right eye for 3 weeks. In her slit-lamp examination, nits and lice, attached to the upper and lower eyelashes of her right eye, were observed. Lice and nits were destroyed by argon laser phototherapy and were removed with the help of a fine forceps thereafter. Argon laser phototherapy is a quick, effective, and safe treatment modality for phthiriasis palpebrarum.

Efficacy of herbal shampoo base on native plant against head lice (Pediculus humanus capitis De Geer, Pediculidae: Phthiraptera) in vitro and in vivo in Thailand.

Head lice infestation (or pediculosis) is an important public health problem in Thailand, especially in children between the ages 5 and 11 years. Head lice resistance is increasing, chemical pediculicides have lost their efficacy, and, therefore, alternative pediculicides such as herbal shampoos have been proposed to treat head lice infestation. Thus, the present study investigated the efficacy of three herbal shampoos based on native plants in Thailand (Acorus calamus Linn., Phyllanthus emblica Linn., and Zanthoxylum limonella Alston) against head lice and compared them with carbaryl shampoo (Hafif shampoo, 0.6% w/v carbaryl), malathion shampoo (A-Lice shampoo, 1.0% w/v malathion), and commercial shampoos (Babi Mild Natural' N Mild and Johnson's baby shampoo) in order to assess their in vitro and in vivo efficacy. For in vitro study, doses of 0.12 and 0.25 ml/cm(2) of each herbal shampoo were applied to filter paper, then 10 head lice were place on the filter paper. The mortalities of head lice were recorded at 5, 15, 30, and 60 min. The results revealed that all herbal shampoo were more effective on pediculicidal activity than chemical and commercial shampoos with 100% mortality at 15 min; LT50 values ranged from 0.25 to 1.90 min. Meanwhile, chemical shampoos caused 20-80% mortality, and LT50 values ranged from 6.50 to 85.43 min. On the other side, commercial shampoos showed 4.0% mortality. The most effective pediculicide was Z. limonella shampoo, followed by A. calamus shampoo, P. emblica shampoo, carbaryl shampoo, malathion shampoo, and commercial shampoo, respectively. In vivo results showed that all herbal shampoos were also more effective for head lice treatment than chemical and commercial shampoos with 94.67-97.68% of cure rate after the first treatment; the second treatment, 7 days later, revealed that the cure rate was 100%. Meanwhile, chemical shampoo showed 71.67-93.0% of cure rate and, unfortunately, commercial shampoos were nontoxic to head lice and showed 0% of cure rate after the first and the second treatments. Our data showed that three herbal shampoos of native plants in Thailand in this study are suitable to be used as pediculicides for Thai children since it is safe for children and there is no side-effect after application.

Pediculicidal effect of herbal shampoo against Pediculus humanus capitis in vitro.

Human head lice infestation is an important public health problem in Thailand. Lice resistance is increasing, chemical pediculicides have lost their efficacy and thus alternative products such as herbal shampoos have been proposed to treat lice infestation. The present study investigated the efficacy of twenty nine herbal shampoos based on zinbiberaceae plants, piperaceae plants and native plants against human head lice and compared them with malathion shampoo (A-lices shampoo®: 1% w/v malathion) and commercial shampoo (BabiMild Natural'N Mild®) in order to assess their in vitro efficacy. All herbal shampoo were more effective than commercial shampoo with 100% mortality at 60 seconds and LT50 values ranged from 11.30 to 31.97 seconds, meanwhile, commercial shampoo caused 14.0-15.0% mortality and LT50 values ranged from 83.96 to 87.43 seconds. The nine herbal shampoos from Zingiber cassumunar, Piper betle, Piper ribesioides, Averrhoa bilimbi, Clitoria ternatea, Plectranthus amboincus, Myristica fragrans, Tacca chantrieri and Zanthoxylum limonella were more effective pediculicide than malathion shampoo with 100% mortality at 30 seconds and LT50 values ranged from 11.30-13.58 seconds, on the other hand malathion shampoo showed LT50 values ranging from 12.39 to 13.67 seconds. LT50 values indicated the order of pediculicidal activity in the herbal shampoos as Z. cassumunar shampoo > P. betle shampoo > Za. limonella shampoo > Av. bilimbi shampoo > P. ribesioides shampoo > My. fragrans shampoo > T. chantrieri shampoo > Pl. amboincus shampoo. Our data showed that eight of the twenty nine herbal shampoos in this study were of high potential pediculicide to human head lice treatments for Thai children.

Effects of a neem seed extract (MiteStop®) on mallophages (featherlings) of chicken: in vivo and in vitro studies.

Mallophages of birds (featherlings) are mostly very tiny and can even as adults better be recognized by their movements than by their elongate body shape when using just the naked eye. Since some species (e.g., the "shaft louse" Menopon gallinae, the elongate feather louse Lipeurus caponis, or Columbicola sp.) may pierce the pulp of feathers or the skin by their biting or scratching mandibles and thus lick the excreted blood, they may be extremely dangerous especially to young birds, even if they only feed by nibbling along the feather surface and/or eat epidermal debris. The present paper reports on the successful treatment of different races of fowls being severely infested with both above cited species. This in vivo treatment was done either by a short dipping of the whole fowl into the 1:33 dilution (with tap water) of a neem seed extract (MiteStop®) or by spraying them with the freshly diluted product. It was seen that the dead mallophages dropped down from the feathers as soon as they were dry again. As a precaution, a second treatment was done by some owners 1 week after the first one in order to eliminate all stages, which eventually might have hatched from untouched nits during the time interval between the two treatments. When controlling the treated fowls 4 weeks after the treatment, in no case (treated once or twice), living motile stages were diagnosed indicating the high efficacy of this nontoxic neem seed extract. When treating in vitro cutoff feathers contaminated with L. caponis, it was seen under the stereomicroscope, that the mallophages tried to run away from the 1:33 water-diluted active compound indicating that there is also a repellent effect. Treated L. caponis stopped leg movements within 3 min and died on their feathers within 1-20 min. Then, the last slight trembling movements of their legs and convulsions of their intestine stopped finally.

Toxicity of essential and non-essential oils against the chewing louse, Bovicola (Werneckiella) ocellatus.

The toxicity of six plant essential oils to the chewing louse, Bovicola (Werneckiella) ocellatus collected from donkeys, was examined in laboratory bioassays. The oils examined were: tea-tree (Melaleuca alternifolia), lavender (Lavandula angustifolia), peppermint (Mentha piperita), eucalyptus (Eucalyptus globulus Labillardiere), clove bud (Eugenia caryophyllata) and camphor (Cinnamomum camphora). All except camphor oil showed high levels of toxicity, with significant dose-dependent mortality and an LC(50) at concentrations of below 2% (v/v). Hundred percent mortality was achieved at concentrations of 5-10% (v/v). Two essential oil components: eugenol and (+)-terpinen-4-ol showed similar levels of toxicity. The data suggest that these botanical products may offer environmentally and toxicologically safe, alternative veterinary pediculicides for the control of ectoparasitic lice.

An ex vivo, assessor blind, randomised, parallel group, comparative efficacy trial of the ovicidal activity of three pediculicides after a single application--melaleuca oil and lavender oil, eucalyptus oil and lemon tea tree oil, and a "suffocation" pediculicide.

BACKGROUND: There are two components to the clinical efficacy of pediculicides: (i) efficacy against the crawling-stages (lousicidal efficacy); and (ii) efficacy against the eggs (ovicidal efficacy). Lousicidal efficacy and ovicidal efficacy are confounded in clinical trials. Here we report on a trial that was specially designed to rank the clinical ovicidal efficacy of pediculicides. Eggs were collected, pre-treatment and post-treatment, from subjects with different types of hair, different coloured hair and hair of different length. METHOD: Subjects with at least 20 live eggs of Pediculus capitis (head lice) were randomised to one of three treatment-groups: a melaleuca oil (commonly called tea tree oil) and lavender oil pediculicide (TTO/LO); a eucalyptus oil and lemon tea tree oil pediculicide (EO/LTTO); or a "suffocation" pediculicide. Pre-treatment: 10 to 22 live eggs were taken from the head by cutting the single hair with the live egg attached, before the treatment (total of 1,062 eggs). TREATMENT: The subjects then received a single treatment of one of the three pediculicides, according to the manufacturers' instructions. Post-treatment: 10 to 41 treated live eggs were taken from the head by cutting the single hair with the egg attached (total of 1,183 eggs). Eggs were incubated for 14 days. The proportion of eggs that had hatched after 14 days in the pre-treatment group was compared with the proportion of eggs that hatched in the post-treatment group. The primary outcome measure was % ovicidal efficacy for each of the three pediculicides. RESULTS: 722 subjects were examined for the presence of eggs of head lice. 92 of these subjects were recruited and randomly assigned to: the "suffocation" pediculicide (n = 31); the melaleuca oil and lavender oil pediculicide (n = 31); and the eucalyptus oil and lemon tea tree oil pediculicide (n = 30 subjects). The group treated with eucalyptus oil and lemon tea tree oil had an ovicidal efficacy of 3.3% (SD 16%) whereas the group treated with melaleuca oil and lavender oil had an ovicidal efficacy of 44.4% (SD 23%) and the group treated with the "suffocation" pediculicide had an ovicidal efficacy of 68.3% (SD 38%). CONCLUSION: Ovicidal efficacy varied substantially among treatments, from 3.3% to 68.3%. The "suffocation" pediculicide and the melaleuca oil and lavender oil pediculicide (TTO/LO) were significantly more ovicidal than eucalyptus oil and lemon tea tree oil pediculicide (EO/LTTO) (P < 0.0001). Ranking: 1. "Suffocation" pediculicide (68.3% efficacy against eggs); 2. Melaleuca oil and lavender oil (44.4%) pediculicide; 3. Eucalyptus oil and lemon tea tree oil (3.3%) pediculicide. The "suffocation" pediculicide and TTO/LO are also highly efficacious against the crawling-stages. Thus, the "suffocation" pediculicide and TTO/LO should be recommended as first line treatments.

[In vitro efficacy of three novel delousing formulations against the head louse (Pediculus capitis L.)]. / Ucinnost trí nových odvsivovacích prípravku na ves detskou (Pediculus capitis L.) v in vitro testech--krátké sdelení.

A total of 498 head lice (2nd and 3rd instar larvae, females and males) combed out of the hair of 38 children, were exposed to the delousing formulations Diffusil H Forte Spray (carbaryl 1%), Diffusil Care (isopropyl myristate, cyclomethicone, and dimethiconol) and Paranit (coconut oil, anise oil, and ylang ylang oil) in in vitro tests. The first two formulations, i. e. Diffusil H Forte Spray and Diffusil Care, caused 100% mortality of exposed lice, while Paranit only killed 12.2% of exposed lice.

Effectiveness of lotions based on essential oils from aromatic plants against permethrin resistant Pediculus humanus capitis.

In Argentina, field populations of the head louse Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae) have developed resistance to permethrin and other pyrethroids. Thus, the aim of this work was the development of a lotion containing essential oils from plants and an alcoholic coadjuvant to improve biological effect. Ethanol + isopropanol (1 + 1 in volume) 50% in water and ethanol 96% were taken as bases for preparation of experimental lotions containing essential oils from plants. We found that experimental lotions containing lavender, peppermint and eucalyptus oils in a 5% composition and the combination of eucalyptus and peppermint in a total concentration of 10%, dissolved in 50% ethanol + isopropanol (1 + 1) in water, showed the best knockdown effect. On the other side, lotion containing peppermint oil and eucalyptus oil (1 + 1) 10%, dissolved in ethanol 96%, showed to be as effective as the best commercial lotion now available in Argentina. Furthermore, addition of 1-dodecanol in all cases increased the effectiveness of all the experimental lotions. This difference is significantly important for 1-dodecanol concentration of 10%, reaching a toxic activity compared to the best commercial lotion available in the market.

Efficacy of neem seed extract shampoo on head lice of naturally infected humans in Egypt.

Sixty heavily lice-infested male and female children (4-15 years) were selected and subjected to the treatment with a neem seed extract shampoo. Twenty to thirty milliliter of the shampoo were thoroughly mixed with completely wet hair and rubbed in to reach the skin of the scalp. After 5, 10, 15 and 30 min, the shampoo was washed out and the hair basically combed. Head lice were collected and examined. The neem seed extract shampoo proved to be highly effective against all stages of head lice. No obvious differences regarding the efficacy of the shampoo were observed between an exposure time of 10, 15 or 30 min. No side effects, such as skin irritation, burning sensations, or red spots on the scalp, forehead or neck, respectively, were observed.

Fumigant and repellent properties of essential oils and component compounds against permethrin-resistant Pediculus humanus capitis (Anoplura: Pediculidae) from Argentina.

The repeated use of permethrin and other insecticides for the control of head lice, Pediculus humanus capitis De Geer (Anoplura: Pediculidae), during past decades has resulted in the development of marked levels of resistance. Thus, new alternative insecticides are needed for the control of head lice. We studied the fumigant and repellent properties of essential oils from 16 native and exotic plants in Argentina, and 21 chemical components against permethrin-resistant head lice from Argentina. With a direct vapor-exposure bioassay, the most effective oil was from the native Myrcianthes cisplatensis Cambess (Myrtaceae) with a time to 50% knockdown (KT50) of 1.3 min, followed by exotic species, Eucalyptus cinerea F.V. Muell., Eucalyptus viminalis Labill., and Eucalyptus saligna Smith. with KT50 values of 12.0, 14.9, and 17.4 min, respectively. The most effective components were 1,8-cineole and anisole, with KT50 values of 11.1 and 12.7 min, respectively. Regression analysis of KT50 values and vapor pressures and water-partition coefficients for the essential oil components revealed that the most effective fumigants were among the more volatile components. Repellency assays indicated that the essential oil from Mentha pulegium L. and its benzyl alcohol component were the most effective repellents, having repellency indices of 75.5 and 57.8%, respectively. Thus, some Argentinean plants contain essential oils and components that function as fumigants or as repellents and thereby show potential for development of new control products for head lice.

Lethality of essential oil constituents towards the human louse, Pediculus humanus, and its eggs.

Essential oils have been widely used in traditional medicine for the eradication of lice, including head lice, but due to the variability of their constitution the effects may not be reproducible. In an attempt to assess the contribution of their component monoterpenoids, a range of common individual compounds were tested in in vitro toxicity model against both human lice (Pediculus humanus, an accepted model of head lice lethality) and their eggs, at different concentrations. No detailed study into the relative potencies of their constituent terpenoids has so far been published. Adult lice were observed for lack of response to stimuli over 3 h and the LT(50) calculated, and the percentage of eggs failing to hatch was used to generate ovicidal activity data. A ranking was compiled for adult lice and partially for eggs, enabling structure-activity relationships to be assessed for lethality to both, and showed that, for activity in both life-cycle stages, different structural criteria were required. (+)-Terpinen-4-ol was the most effective compound against adult lice, followed by other mono-oxygenated monocyclic compounds, whereas nerolidol was particularly lethal to eggs, but ineffective against adult lice.

Eficacia de los pediculicidas en la pediculosis capitis / Efficacy of pediculicidal drugs in pediculosis capitis

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Argon laser phototherapy of phthiriasis palpebrarum.

Argon laser phototherapy is an alternative new, quick, and effective method of treating phthiriasis palpebrarum in one sitting. A beam at a setting of 200-microns size, 0.1 second time, and 200 mW power is employed to destroy individual adult parasites and nits. The only drawbacks are an occasional but tolerable stinging and the slicing of the eyelash stems carrying the nit. The eyelashes regain their normal length within a few days.