Pediculicidal Activity Research Articles

Phytochemistry and Bioactivities of Duguetia furfuracea (A.St.-Hil.) Saff.

Duguetia furfuracea, belonging to the Annonaceae family, is a perennial plant found in the Central-West, Southeast, and Northeast regions of Brazil, known for its various uses in traditional medicine. Used as a hypocholesterolemic, anorexigenic, and for treating various conditions including cancer and infections, its medicinal properties have garnered scientific interest. Studies have identified several bioactive compounds in different parts of the plant. The leaves contain phenolic acids, flavonoids, and alkaloids such as duguetine and dicentrinone, which exhibit antioxidant, anti-inflammatory, and antimicrobial properties. Phytochemical analysis revealed the presence of rare sesquiterpenes such as α-santalene and (-)-ishwarane, strengthening the chemotaxonomic relationship between Annonaceae and Aristolochiaceae. The species has shown larvicidal activity against Aedes aegypti, pediculicidal activity against Pediculus capitis, and antiplasmodial activity against Trypanosoma cruzi. Additionally, it possesses anti-inflammatory, antinociceptive, and cytotoxic activities, being effective against Candida spp. strains and cancer cells. However, its toxicity was observed in studies with Drosophila melanogaster and cellular models, indicating the need for further studies to ensure its safe use. The plant shows potential for therapeutic applications due to its chemical diversity, but it is essential to deepen investigations into its mechanisms of action and develop extraction and isolation methods to maximize its medicinal potential safely and effectively. Continued research is crucial to integrate D. furfuracea into modern phytotherapy and the development of new drugs. The presence of these bioactive compounds highlights the importance of exploring the full pharmacological potential of D. furfuracea for future therapeutic advancements, emphasizing its promising role in natural medicine. the pharmacological properties of D. furfuracea underscore its potential for innovative drug development and traditional medicinal enhancement.

Effectiveness and chemical insights: Exploring interactions between nanomicelles and monoterpenoids for head lice treatment

This study evaluates the pediculicidal activity of nanoformulations containing different binary essential oil component mixtures (eugenol:linalool, 1,8 -cineole:linalool, and eugenol:thymol) using immersion bioassays. These have allowed us to evaluate the knockdown time affecting 50% of the individuals (KT50). In addition, the type of interaction between the components in each mixture was established in terms of the combination index (IC). The KT50 values were 6.07; 8.83; 7.17 and 27.23 h for linalool, 1,8 -cineole, eugenol, and thymol, respectively. For the eugenol:linalool mixtures, the efficacy was lower or equal to that obtained for the nanoformulations of the pure compounds, with values of KT50 about 13.33, 8.16 and 6.71 h for mixtures with ratios 3:1, 1:1 and 1:3, respectively. These mixtures present IC > 1, evidencing antagonistic interaction, which is enhanced with eugenol content. In the case of the binary mixtures of 1,8 -cineole: linalool, KT50 values were similar to those obtained for eugenol:linalool mixtures with similar ratios. In this case, IC assumes values close to unity, suggesting additive interactions independently of the mixture composition. On the other side, mixtures of eugenol:thymol with 1:1 and 1:3 ratios showed values of 9.40 and 32.93 h, while the mixture with a 3:1 ratio showed the greatest effectiveness (KT50 of 4.42 h). Eugenol:thymol mixtures show synergistic interaction (IC < 1) for combinations 3:1 and 1:1, while no interaction was observed for 1:3 combination. This indicates that eugenol enhances thymol activity. These results must be considered an important step forward to the development of effective pediculicidal nanoformulations based on botanical compounds.

Essential Oil of Eucalyptus: A Natural Solution for Treating Pediculosis

Objective: Pediculosis is a condition caused by the infestation of Pediculus Humanus Capitis. The pesticides used in current formulations exhibit toxicity and carcinogenic effects on consumers. This study aimed to investigate the pediculicidal activity of the essential oil from Eucalyptus Globulus leaves, with the intention of adding it as an active ingredient in pediculicidal formulations to replace harmful chemicals.&#x0D; Design/methodology/approach: In vivo tests were conducted to assess the repellency and mortality of the essential oil obtained through hydrodistillation. The major components were determined through gas chromatography-mass spectrometry analysis. Additionally, proximate, and chemical composition analyses were performed on the eucalyptus leaves using ASTM E871, ASTM E872, ASTM D1104, TAPPI T264, TAPPI T207, ASTM D1106, and ASTM D1104 methods.&#x0D; Results: A repellency of 66.66% and 100% mortality within 2.26 minutes were obtained in the in vivo tests. The yield of hydrodistilled essential oil was 4 mL/kg, primarily composed of 71.04% 1,8-cineole, 18.94% 4-Ethyl-m-xylene, 2.72% γ-Terpinene, and 1.23% L-α-Pinene. Furthermore, the composition of eucalyptus leaves was determined as 61.25% moisture, 30.32% volatile matter, 6% ash, 2.40% fixed carbon, 11.22% acetone extractives, 33.03% water extractives, 31.49% lignin, 69.33% holocellulose, 62.09% cellulose, and 7.24% hemicellulose.&#x0D; Limitations on study/implications: The pediculicidal activity study was conducted solely on the essential oil, and further testing on the formulation of the finished product is necessary.&#x0D; Findings/conclusions: The pediculicidal activity study was conducted solely on the essential oil, and further testing on the formulation of the finished product is necessary.

Comparative efficacy of chemical and botanical pediculicides in Thailand and 4% dimeticone against head louse, Pediculus humanus capitis.

Head louse infestations remain a global public-health concern due to increased resistance of lice to artificial pediculicides. In Thailand, there is a lack of comparative data on the current efficacy of pediculicides for treating head lice. In this study, we explored the status of botanical and toxic synthetic pediculicides with that of 4% dimeticone liquid gel for treating head lice in Thailand. The ex-vivo pediculicidal activity of various pediculicidal shampoos available at drugstores in Thailand was assessed and compared with that of 4% dimeticone liquid gel. The shampoos chosen were based on active ingredients toxic to lice (1% permethrin, 0.6% carbaryl, 0.15% Stemona root crude extract, or mixed plant extracts), whereas dimeticone acts physically on lice. We found that exposure to 4% dimeticone liquid gel following the manufacturer's instructions completely killed 100% of head lice in 15 min, whereas other pediculicide products failed to kill the great majority of head lice, whether treatment was for 10 min (resulting in 0% to 50.0% mortality) or 30 min (resulting in 17.0% to 60.0% mortality). We also extended a clinical assessment to confirm the efficacy of 1% permethrin for treating head lice in infested schoolchildren. In this clinical assessment, none of the 26 children treated with 1% permethrin shampoo achieved a cure after two applications. These results highlight that 4% dimeticone demonstrated a higher ex-vivo pediculicidal efficacy compared to both chemical and botanical pediculicides in Thailand. Conversely, 1% permethrin showed low efficacy in both laboratory and clinical assessments. Given its physical mode of action, 4% dimeticone merits consideration as an alternative treatment option for lice in Thailand, particularly in cases where treatment with toxic pediculicides has proven ineffective.

Pediculicidal Activity of Foeniculum vulgare Essential Oil in Treatment of Pediculus capitis as a Public Health Problem.

Pediculosis, caused by Pediculus spp is an important public health problem in urban and rural areas around the world. Natural compounds such as plant essential oils (EOs) have been suggested as a potential alternative for insect pest control recently. The purpose of this study was to investigate the toxicity of Foeniculum vulgare essential oil against the head louse, Pediculus capitis under laboratory conditions. Fennel essential oil components were analyzed using GC-mass apparatus. Immersion and contact filter paper bioassays were used to evaluate fennel essential oil toxicity at the two-fold concentrations of 2.5, 5, 10, 20, and 40% against nit and nymph/adult stages of the head louse. Trans-anethole, α-Thujone, and limonene, which consisted of 76.08%, 10.37%, and 5.34% were the most components of fennel oil respectively. The LC50 values for the adult /nymphs were 11.5, 6.4, 3.9, 3.1 and 2.5% and LC99 values were 29.5, 15.2, 12.8, 10.8, and 7.4% at 10, 20, 30, 45 and 60 minutes after exposure respectively. The lethal times (LT50) for adults/nymphs were 5.2, 8.1, 9.5, 20.5, and 45.8 minutes and LT99 were 138.6, 91.3, 23.8, 21.7, and 13.9 minutes in the concentrations of 2.5, 5, 10, 20 and 40%, respectively. LC50 and LC99 values were 2.32% and 7.36% after 5 days for the eggs. Fennel essential oil at the concentration of 15% after 20min is suggested to develop as an appropriate formulation to evaluate in clinical trials.

The Efficacy and Biopharmaceutical Properties of a Fixed-Dose Combination of Disulfiram and Benzyl Benzoate.

Scabies and hair lice are parasitic diseases that affect human skin and hair, respectively. The incidence and resistances of these infections are increasing. Tenutex® (disulfiram and benzyl benzoate emulsion) is an alternative to standard insecticides to avoid resistances. The aim of the work is to evaluate the transdermal absorption and the in vitro efficacy against scabies and hair lice after different exposition times. Dermatomed human skin was used to assess the dermal absorption using a validated High Performance Liquid Chromatography (HPLC) method. HEK001 keratinocytes were used to evaluate the cytotoxicity of benzyl benzoate. Only benzyl benzoate was able to cross the skin, but it did not show cytotoxicity at any of the tested concentrations. The product efficacy was tested on Psoroptes ovis after direct contact and after administration on sheep skin explants at different contact times. Permethrin/malathion-resistant strains of Pediculus humanis capitis adults and eggs were directly exposed to Tenutex, and the vitality and hatchability, respectively, were evaluated. The anti-scabies study demonstrated that exposure for 6 or 24 h completely eradicated the parasite. The pediculicidal activity of Tenutex exhibited superior efficacy than standard treatment on resistant lice. The positive results obtained suggest that Tenutex® is a good treatment option, especially in drug resistance situations.

Информационно–методическое письмо "Анализ заболеваемости педикулёзом в Российской Федерации и использование современных педикулицидных средств для его лечения и профилактики (по состоянию на 01.01 2022)"

The morbidity of human lice in the Russian Federation in 2016–2021 was analyzed. High intensive infection rates were registered in the Central, Northwestern and Far Eastern Federal Districts. The maximum level of pediculosis infestation of the population was noted in Moscow (88.7–96.1 % of all cases of this disease in the Central Federal District). The resistance of lice to permethrin led to a decrease in the pediculicidal activity of pediculicides based on it. The range of modern drugs effective against permethrin-resistant head and body lice and the dynamics of the ratio of pediculicides based on substances from different groups of insecticides during 1991–2021 were analyzed. Keywords: pediculosis, Pediculus humanus, resistance, pyrethroids, pediculicides.

Biochemical constituents and insecticidal activities of Callistemon viminalis essential oil against adults and eggs of Pediculus humanus capitis (Phthiraptera: Pediculidae)

BackgroundSynthetic chemical pediculicides used for head-louse treatment do not kill louse eggs, can induce side effects in humans, and lead to genetic resistance in lice worldwide, including in Thailand. Use of phytoconstituents, particularly plant-derived essential oils, is alternatively recommended for head lice. PurposeTo identify biochemical constituents of Callistemon viminalis essential oil (EO) and to assess the ex vivo effects of EO on head lice and their eggs. MethodsThe EO was extracted from fresh leaves C. viminalis by stream distillation, and the biochemical constituents were identified by gas chromatography-mass spectrometry (GC–MS). Louse samples were collected from schools in Khon Kaen Province, Thailand for ex vivo tests. Pediculicidal activity of EO was investigated using topical contact, and ovicidal activity was assessed using immersion and topical tests. Adult lice were observed for 8 h after treatment and eggs were observed for 3 weeks to assess pediculicidal and ovicidal effects, respectively. Mortality was noted and morphological change was recorded for head lice using scanning electron microscopy. Inhibition of egg hatching was evaluated. ResultsForty-four phytochemical components were identified in EO obtained from fresh leaves of C. viminalis. The most abundant were 1,8-cineole (66.96%), α-pinene (18.74%) and o-cymene (7.02%). Ex vivo, C. viminalis EO at concentrations above 10% for 30 min caused 100% adult mortality using a topical bioassay. In a complete-immersion test, all head louse eggs failed to hatch after exposure to concentrations of C. viminalis EO of 10% or greater for 10 min. Eggs were less sensitive using a topical method. Permethrin 1%, coconut oil and distilled water exhibited low efficacy against both crawling and egg stages. Scanning electron micrographs indicated that C. viminalis EO caused obstruction in some louse spiracles but had no effect on the cuticle or sensory hairs. ConclusionThe EO derived from C. viminalis had higher ex vivo efficacy against head lice and their eggs than 1% did permethrin. This EO may be a starting point for developing natural pediculicides to control head lice that are susceptible or resistant to permethrin.

Pediculicidal Activity of Cem-ceman White Cempaka Flower (Michelia alba DC.) against Pediculus humanus capitis

The prevalence of pediculosis reported in Asia has ranged from 0.7% to 59%. High resistance and side effects is a challenge in using the pediculicidal agents. The widely use and empirical as well as scientific studies of traditional plants for anti-lice were already done, one of them is cempaka. The aim of this study was to determine the pediculicidal activity of cem-ceman white cempaka flower (Michelia alba DC.) on Pediculus humanus capitis in vitro. The white cempaka flowers made into cem-ceman preparations by mixing and soaking in coconut oil until 3 days. Pediculisidal activity was tested by filter paper diffusion test method with 3 replications. Data were analyzed using Kruskal-Wallis followed by post hoc Mann-Whitney Method test with software SPSS v.16. The phytochemical screening showed that sample contains alkaloid, tannin, saponin, and triterpenoid. Pediculidal activity test showed that cem-ceman white cempaka flower has pediculicidal effect in 10% concentration (w/v) with 66.67% mortality and 15% concentration (w/v) with 77.33% mortality. In conclusion cem-ceman white cempaka flowers has pediculicidal activity at concentration 10% and 15% but lower than permethrin 1% (p&lt;0.05).

The Toxicity of Essential Oils From Three Origanum Species Against Head Louse, Pediculus humanus capitis.

Pediculosis caused by human head louse, Pediculus humanus capitis De Geer (Anoplura: Pediculidae) is a public health problem with a high prevalence, especially among children in school age. Different chemical pediculicides (insecticides) are used against lice but the repeated application of these pediculicides for the treatment of P. humanus capitis infestation in the past decades has resulted in the development of resistance. The plant essential oils have been used as alternative sources of lice treatment agents. Pediculicidal activity of the essential oils of three Origanum species (O. onites, O. majorana and O. minutiflorum) against P. humanus capitis adults was examined in this study. Essential oils from aerial parts of three Origanum species were obtained by hydrodistillation using a Clevenger-type apparatus. P. humanus capitis specimens used were obtained from infested children by combing method at primary schools. Adult lice were exposed to three dilutions (1%, 0.5% and 0.1% w/v) of tested oils for 5min using the adult immersion test. According to the results, all Origanum essential oils at 1% concentration have been shown to significantly decrease the rate of limb, bowel and abdomen movements, producing more than 90% mortality after 12h. Our results indicated that Origanum essential oils can be used for the development of new pediculicides against head louse.

Anti-oxidant, pediculicidal and pesticidal activities of leaves of Rhinacanthus nasutus (Linn) grown in Sri Lanka

Rhinacanthus nasutus is an ethnomedical plant used in the traditional system of medicine for treating skin diseases. As no adequate studies available on R. nasutus grown in Sri Lanka, this study aimed on exploring anti-oxidant, anti-parasitic and pesticidal activity of leaves of the plant. Antioxidant capacity of the crude extract of leaves was evaluated using DPPH free radical scavenging assay and FRAP assay using ascorbic acid and FeSO4.7H2O as the standards respectively. Pediculicidal efficacy was carried out against head lice using 0.0010% (w/v) methanolic, ethyl acetate and aqueous extracts of leaves by following modified filter paper diffusion bioassay. Pesticidal activity of leaves was evaluated using modified filter paper contact bioassay against mealybugs, P. marginatus, resides on papaw and guava trees. The IC50 value of DPPH assay was found to be 514.3 μgmL-1 and FRAP value was found to be 594.33±2.93 μmol Fe2+/g in anti-oxidant assay. The LT50 (median Lethal Time) values for 0.0010% (w/v) concentration of methanolic, ethyl acetate and aqueous extracts were 263, 347 and 676 min respectively in pediculicidal assay. LC50 (50% mortality) value was found to be 0.0011% (w/v) after 240 minutes whereas LT50 values of 0.0020% (w/v) of methanol, ethyl acetate and aqueous fractions of R. nasutus for adult were found as 31, 124 and 189 hours and for nymph were 14, 18 and 29 hours respectively in pesticidal assay. Accordingly, methanolic extract was effective in controlling nymph stage of mealybug life cycle than adults with the LC50 of 0.0015% (w/v) within 14 hours. This study confirmed promising pediculicidal and pesticidal activity and significant anti-oxidant capacity of leaves of R. nasutus.&#x0D; Asian J. Med. Biol. Res. December 2020, 6(4): 754-760

Topical ivermectin in the treatment of pediculosis capitis

Background: Head lice infestation is considered a prominent issue because of its worldwide distribution, especially among children. Millions of children are infested with pediculosis capitis every year. The increasing rate of lice infestation has been reported even in the developed countries due to the resistance to known pediculicides. Besides, the louse is a vector for serious diseases, such as epidemic typhus fever. Objective: The aim of this work was the search for a new cheap and effective drug for pediculosis capitis. 2% ivermectin solution, a promising novel drug used for endoparasite and ectoparasite infections, was used in this study. Materials and Methods: This was a clinical trial study. The in vitro study was carried out in a period of five months. Samples of nits and lice were collected from female patients of the Department of Dermatology and Venereology, Baghdad Teaching Hospital. The study was conducted during a period from October 2002 through November 2003. One hundred fifty children from four primary schools in Hayy Al-A’amel, Baghdad, participated in this part of the study. The preparation was applied to the children by the author. One hundred children were tested with ivermectin solution and fifty children with rectified spirit. The first part of the study involved a parasitological evaluation (in vitro study) of pediculicidal and ovicidal activity, in which 4% ivermectin solution was discontinued because of contact dermatitis. Therefore, 2% ivermectin solution was used instead. Pediculicidal and ovicidal activity was examined half an hour afterward. The second part of the study involved a clinical evaluation (in situ study) of 2% ivermectin solution for half an hour. Results: Topical 2% ivermectin solution in rectified spirit is a good pediculicidal (100%) and a good ovicidal (88%) drug with good therapeutic efficacy (82% after the first application, 90% after the second application) against pediculosis capitis. Conclusion: The study described a novel topical preparation for pediculosis capitis, which was proven effective and safe.

Essential Oils as a Potential Treatment Option for Pediculosis.

Pediculosis is a prevalent ectoparasite infestation caused by lice. The head louse (Pediculus humanus capitis) and body louse (Pediculus humanus humanus) are obligatory parasites whose only known hosts are humans. Pediculosis is probably the most common ectoparasitic infestation, affecting up to 80% of the population in several countries, and particularly prevalent in the infant population worldwide. Several treatment options, including shampoos and creams containing insecticides, have been introduced for the treatment of pediculosis. Recently, the use of synthetic chemicals to control human lice has raised concerns pertaining to human health and the environment. Therefore, increasing efforts have been undertaken to develop effective pediculicides with low environmental toxicity and minimal environmental residual activity. In this study, we focus on the essential oils derived from 22plant genera, their constituents, and the major factors that play important roles in the effectiveness of these oils in the treatment of pediculosis. Furthermore, we discuss the advantages and limitations of the mentioned essential oils, and ultimately suggest those demonstrating the most effective in vitro pediculicidal activities. The genera such as Aloysia, Cinnamomum, Eucalyptus, Eugenia, Lavandula, Melaleuca, Mentha, Myrcianthes, Origanum, Pimpinella, and Thymus appear to be more efficient against lice. These genera are rich in anethole, 1,8-cineole, cinnamaldehyde, p-cymene, eugenol, linalool, limonene, pulegone, terpinen-4-ol, and thymol compounds.

Pediculicidal activity assessment of four essential oil terpenoids using filter contact and immersion bioassays.

Pediculicidal activity assessment of four essential oil terpenoids using filter contact and immersion bioassays.

In Vitro Effectiveness of Neem Oil (Azadirachta Indica A. Juss) Shampoo as Anti Head Lice (Pediculus humanus capitis)

Head lice (Pediculus humanus capitis), a parasite causing hair problem, often occurs in society.The study aimed to evaluate in vitroeffectiveness of shampoo formulation containing neem oil as an anti head lice. An experimental method was used to examine the formulation of shampoo, irritation test, testing the effectiveness of shampoo against head lice (Pediculicidal activity), and testing the effectiveness of shampoo against nits (Ovicidal activity). The effectiveness test employed an in vitromethod where neem oil shampoo were tested directly towards head lices and nits isolated from humans, then the mortality was observed. To recognize the safety of the shampoo, skin and eye irritation tests were carried out by applying 0.5 ml on the skin and dripping 0.1 ml shampoo into New Zealand white rabbit’s eyes.Data were analyzed using Kruskal Wallis and Mann Whitney. The study results showed that the primary irritation index for 5%, 10%, 15%, and 20% neem oil shampoo were 0; 0111; 0.222; and 0.222, respectively. All of the shampoos were very mild irritation response category. Eye irritation tests showed that only the 20% neem oil shampoo gave a mild irritation response with degree of corneal opacity ≥ 1 and recovered after 7 days of observation. The 5%, 10%, 15%, and 20% neem oil shampoo were effective as an anti head lice. The 15% and 20% neem oil shampoo had anti head lice effectiveness activity as same as 1% permethrin lotion. In conclusion, the 15% neem oil shampoo was chosen as the best shampoo, its high anti head lice effect and light irritation response. Keywords: Head lice, neem oil (Azadirachta indica A. Juss), shampoo

High efficacy of a dimeticone-based pediculicide following a brief application: in vitro assays and randomized controlled investigator-blinded clinical trial

BackgroundIncreasing resistance of head lice against neurotoxic agents and safety concerns have led to the search for treatment alternatives. Dimeticones with a physical mode of action are safe, and bear a reduced risk for the development of resistance.MethodsWe performed in vitro bioassays to assess pediculicidal and ovicidal activities of a new dimeticone-based product, and a randomized controlled clinical trial to assess efficacy, following 10 min application. Of 153 individuals screened, 100 participants with active head louse infestations were randomly assigned to treatment with either a dimeticone-based test product, or a 0.5% permethrin-based reference product (50 participants per group). Participants received two topical applications of either the test (10 min) or reference products (45 min) at days 0 and 7 or 8. Outcome measures included the efficacies of treatment and their safety, as well as global and local tolerability at baseline, and days 1, 7, and 10.ResultsAfter 10 min exposure, all lice treated with the dimeticone test product were classified as non-viable in the in vitro assay. Ovicidal activity after treatment of eggs with the dimeticone test product was 96.8%. In the clinical trial, 96 patients completed all study visits. In the full analysis set (FAS) population, on day 1 after one application, 98% of patients were cured in the test group, as compared to 84% cured in the reference group. All participants in both groups were free of head lice on day 10, following two applications (100% cure rate). In total, 42 adverse events (AEs) in 23 patients of both treatment groups were recorded, with the majority of AEs classified as mild.ConclusionsWe have shown a high level of pediculicidal and ovicidal activity, and clinical efficacy and safety, of a brief application of a new dimeticone-based product. The short application time and reduced risk for the development of resistance are key drivers for improved patients’ compliance.Trial registrationEU Clinical Trials Register EudraCT 2016–004635-20. Registered 14 November 2016.

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

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). 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. 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. The results showed that the volatile oil of Rosmarinus officinalis (two different chemotypes) was more effective than the other oils.

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.

Novel polymeric micelles for insect pest control: encapsulation of essential oil monoterpenes inside a triblock copolymer shell for head lice control.

BackgroundEssential oil components (EOCs) are molecules with interesting application in pest control, these have been evaluated against different insect pest from more than 100 years, but their practical use is rather limited. Thus, the enhancement of their bioavailability and manageability due to their dispersion in water can open new perspective for the preparation of formulations for the control of insect pest. In this work, we studied the encapsulation of different monoterpenes in a poloxamer shell in order to prepare aqueous formulations that can be used for the development of platforms used in pest control.MethodsMicellar systems containing a 5 wt% of poloxamer 407 and 1.25 wt% of the different monoterpenes were prepared. Dynamic Light Scattering (DLS) experiments were carried out to characterize the dispersion of the EOCs in water. The pediculicidal activity of these micellar systems was tested on head lice using an ex vivo immersion test.ResultsThe poloxamers allowed the dispersion of EOCs in water due to their encapsulation inside the hydrophobic core of the copolymer micelles. From this study, we concluded that it is possible to make stable micellar systems containing water (>90 wt%), 1.25 wt% of different monoterpenes and a highly safe polymer (5wt% Poloxamer 407). These formulations were effective against head lice with mortality ranging from 30 to 60%, being the most effective emulsions those containing linalool, 1,8-cineole, α-terpineol, thymol, eugenol, geraniol and nonyl alcohol which lead to mortalities above 50%.DiscussionSince these systems showed good pediculicidal activity and high physicochemical stability, they could be a new route for the green fabrication of biocompatible and biosustainable insecticide formulations.

Larvicidal and pediculicidal activity of synthesized TiO2 nanoparticles using Vitex negundo leaf extract against blood feeding parasites

Insecticide resistance and inadequate attention to the application instructions of topical pediculicides are common reasons for treatment failure. Essential oils or plant extracts are good and safe alternatives due to their low toxicity to mammals and easy biodegradability. The present study was carried out to establish the larvicidal and the pediculicidal activity of synthesized titanium dioxide nanoparticles (TiO2 NPs) using the leaf aqueous extract of Vitex negundo (Verbenaceae) against the fourth instar larvae of the malaria vector, Anopheles subpictus Grassi and filariasis vector, Culex quinquefasciatus Say (Diptera: Culicidae) and the head louse, Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae). The synthesized TiO2 NPs were characterized by UV, XRD, FTIR and SEM-EDX. The SEM analyses were clearly indicated that the spherical shape of the synthesized TiO2 NPs. Mosquito larvae and head lice were exposed to varying concentrations of the synthesized TiO2 NPs, V. negundo leaf aqueous extract and titanium tetrachloride (TiCl4) for 24h. The maximum activity was observed in the synthesized TiO2 NPs against A. subpictus, C. quinquefasciatus and lice, (LC50=7.52, 7.23 and 24.32mg/L; χ2=0.161, 2.678 and 4.495; r2=0.663, 0.742 and 0.924), respectively. The TiO2 NPs did not exhibit any noticeable toxicity on Poecilia reticulata after 24h of exposure. The findings revealed that the synthesized TiO2 NPs possess excellent mosquito larvicidal and anti-lice activity. These results suggest that the green synthesis of TiO2 NPs has the potential to be used as an ideal eco-friendly approach for the control of vectors and head lice.