In vitro efficacy of essential oils against Sarcoptes scabiei

In vitro efficacy of essential oils against various Candida species

Candida species are responsible for the most common fungal infections worldwide. We studied the in vitro antifungal activity of a large panel of essential oils (EOs) against various Candida species. The EOs activity against Candida spp. was tested using a gradient microdilution assay ranging from 4% to 0.008% (v/v). After a preliminary screening including 31 EOs, seven selected EOs were tested against 13 clinical isolates and four reference strains belonging to six Candida species. Cinnamomum zeylanicum and Cymbopogon giganteus EOs exhibited the best antifungal activity against all clinical and reference strains, with MIC ranges of 0.015%-0.25% (v/v). EOs from Litsea citrata, Backhousia citriodora and Ocimum sanctum presented MIC ranges of 0.03%-0.5% (v/v). The antifungal efficacy of EOs was independent of the susceptibility of Candida strains to usual antifungal agents. These EOs could have a promising antifungal action.

In Silico Exploration and Experimental Validation of Camellia sinensis Extract against Rhipicephalus microplus and Sarcoptes scabiei: An Integrated Approach

Sarcoptes scabiei is an ectoparasite of humans and animals that causes scabies. The Rhipicephalus (Boophilus) microplus is a blood-sucking ectoparasite that transmits various pathogens. These two parasites have caused great losses to a country's dairy and agriculture sectors. The aim of this study was to determine the in vitro and in silico efficacy of Camellia sinensis plant extracts. Different concentrations of C. sinensis ethanolic plant extracts were prepared using the maceration method and were used against mites and ticks (in adult immersion test AIT and larval packet test LPT) to evaluate their in vitro acaricidal activity. Additionally, in silico molecular docking was performed to investigate the inhibitory interactions between the phytochemicals of the plant and S. scabiei and R. microplus glutathione transferase proteins (SsGST and RmGST). This study observed that the plant extract showed high efficacy in vitro against mites and different tick stages in adult immersion and larval packet tests. Additionally, the in silico study revealed a strong binding interaction between ellagic acid and SsGST protein, with a binding energy of -7.3 kcal/mol, with respect to permethrin (-6.7 kcal/mol), whereas quercetin and RmGST resulted in a docking score of -8.6 kcal/mol compared to deltamethrin (-8.2 kcal/mol). Overall, this study explored the potential of C. sinensis as a natural alternative for controlling tick and mite infestations and provided insights into the inhibitory mechanisms of its phytochemicals.

Natural Products as Mite Control Agents in Animals: A Review

Mites have been a persistent infectious disease affecting both humans and animals since ancient times. In veterinary clinics, the primary approach for treating and managing mite infestations has long been the use of chemical acaricides. However, the widespread use of these chemicals has resulted in significant problems, including drug resistance, drug residues, and environmental pollution, limiting their effectiveness. To address these challenges, researchers have shifted their focus towards natural products that have shown promise both in the laboratory and real-world settings against mite infestations. Natural products have a wide variety of chemical structures and biological activities, including acaricidal properties. This article offers a comprehensive review of the acaricidal capabilities and mechanisms of action of natural products like plant extracts, natural compounds, algae, and microbial metabolites against common animal mites.

Egyptian mandarin peel oil's anti-scabies potential via downregulation-of-inflammatory/immune-cross-talk: GC-MS and PPI network studies

The current study investigated the scabicidal potential of Egyptian mandarin peel oil (Citrus reticulata Blanco, F. Rutaceae) against sarcoptic mange-in-rabbits. Analysis of the oil's GC-MS identified a total of 20 compounds, accounting for 98.91% of all compounds found. Mandarin peel oil topical application improved all signs of infection, causing a scabicidal effect three days later, whereas in vitro application caused complete mite mortality one day later. In comparison to ivermectin, histopathological analysis showed that the epidermis' inflammatory-infiltration/hyperkeratosis-had disappeared. In addition to TIMP-1, the results of the mRNA gene expression analysis showed upregulation of I-CAM-1-and-KGF and downregulation of ILs-1, 6, 10, VEGF, MMP-9, and MCP-1. The scabies network was constructed and subjected to a comprehensive bioinformatic evaluation. TNF-, IL-1B, and IL-6, the top three hub protein-coding genes, have been identified as key therapeutic targets for scabies. From molecular docking data, compounds 15 and 16 acquired sufficient affinity towards the three screened proteins, particularly both possessing higher affinity towards the IL-6 receptor. Interestingly, it achieved a higher binding energy score than the ligand of the docked protein rather than displaying proper binding interactions like those of the ligand. Meanwhile, geraniol (15) showed the highest affinity towards the GST protein, suggesting its contribution to the acaricidal effect of the extract. The subsequent, MD simulations revealed that geraniol can achieve stable binding inside the binding site of both GST and IL-6. Our findings collectively revealed the scabicidal ability of mandarin peel extract for the first time, paving the way for an efficient, economical, and environmentally friendly herbal alternative for treating rabbits with Sarcoptes mange.

In Vitro Efficacy of Terpenes from Essential Oils against Sarcoptes scabiei

The mite Sarcoptes scabiei is responsible for the emerging or re-emerging skin disease called scabies in humans and sarcoptic mange in animals. Essential oils represent an appealing alternative strategy for the control of Sarcoptes infections, but the commercial development of essential oils may be hampered by their inconsistency in efficacy due to their varied chemical compositions. In order to address this issue, we assessed the efficacy of six components (carvacrol, eugenol, geraniol, citral, terpinen-4-ol, and linalool) against S. scabiei. At a concentration of 0.5%, carvacrol presented the best miticidal efficacy, with a median lethal time (LT₅₀) value of 6.7 min, followed by eugenol (56.3 min), geraniol (1.8 h), citral (6.1 h), terpinen-4-ol (22.3 h), and linalool (39.9 h). The LC₅₀ values at 30 min for carvacrol, eugenol, and geraniol were 0.24, 0.79, and 0.91%, respectively. In conclusion, carvacrol, eugenol, and geraniol represent potential complementary or alternative agents for S. scabiei infections in humans or animals. Our study provides a scientific basis for the development of scabicidal products based on essential oils.

Scabicidal Potential of Coconut Seed Extract in Rabbits via Downregulating Inflammatory/Immune Cross Talk: A Comprehensive Phytochemical/GC-MS and In Silico Proof

Scabies is an invasive skin condition caused by Sarcoptes scabiei mites. The present study investigates the antiscabies potential of coconut seed extract (CSE) in rabbits. GC-MS analysis of the seed oil identified 17 known compounds, while CSE phytochemical investigation afforded 4 known ones. The topical application of seed extract improved all signs of infection, and the improvement started 3 days post application. However, in vitro application of the extract caused 99% mortality of mites 1 day post application. Histopathological examination revealed the absence of inflammatory infiltration and hyperkeratosis of the epidermis, compared with ivermectin-treated groups which revealed less improvement. The mRNA gene expression results revealed a suppression of IL-1β, IL-6, IL-10, MMP-9, VEGF, and MCP-1, and an upregulation of I-CAM-1, KGF as well as TIMP-1. The docking analysis emphasized a strong binding of gondoic acid with IL-1β, IL-6, and VEGF with high binding scores of -5.817, -5.291, and -8.362 kcal/mol, respectively, and a high binding affinity of 3″(1‴-O-β-D-glucopyranosyl)-sucrose with GST with -7.24 kcal/mol. Accordingly, and for the first time, our results highlighted the scabicidal potential of coconut seed extract, which opens the gate for an efficient, cost-effective as well as herbal-based alternative for the control of scabies in rabbits.

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.

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.

Chemical Composition and Antibacterial and Antioxidant Activities of Stem Bark Essential Oil and Extracts of Solanecio gigas

Herbal medication developed from natural resources has to have antibacterial and antioxidant effects. The aim of this research is to look at the chemical makeup of Solanecio gigas (S. gigas) stem bark essential oil (EO), as well as the effectiveness of EO and extracts (chloroform, ethyl acetate, and methanol) against human pathogenic bacteria and their antioxidant activity. The GC-MS analysis identified 23 components, accounting for 98.7% of the total oil containing Methylene chloride (49.2%), sabinene (10.5%), 1-nonene (11.3%), Terpinen-4-ol (6.9%), Camphene (4.3%), γ-terpinene (3.6%), α-phellandrene (2.9%) β-myrcene (2.6%), 1,2,5-Oxadiazol-3-carboxamide, 4,4′-azobis-2,2′-dioxide (2.4%), α-terpinene (1.9%), 1-Octanamine, N-methyl- (1.9%), ρ-cymene (1.6%) as major components. The antibacterial efficacy of the EO and extracts (25, 50, 100, and 200 mg/ml) was demonstrated by the inhibitory zones (8.5 ± 0.47–23.3 ± 0.36 and 7.2 ± 0.25–22.0 ± 0.45 mm), respectively. The MIC values of the extracts and the EO were 120–150 and 240 to <1100 μg/ml, respectively. The EO also demonstrated a significant antibacterial impact. The EO and methanolic extract had free radical scavenging activities with IC₅₀ value, 13.8 ± 0.48 and 4.2 ± 0.04 μg/ml, respectively. In comparison to the other extracts, the methanolic extract had the greatest phenolics (100.2 ± 0.13 μg GAE/mg of dry extract) and flavonoid contents (112.1 ± 0.18 μg CE/mg of dry extract).