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.

Antimicrobial drugs applied topically offer several advantages. However, the widespread use of antibiotics has led to increasing antimicrobial resistance. One interesting approach in the drug discovery process is drug repurposing. Disulfiram, which was originally approved as an anti-alcoholism drug, offers an attractive alternative to treat topical multidrug resistance bacteria in skin human infections. This study aimed to evaluate the biopharmaceutical characteristics of the drug and the effects arising from its topical application in detail. Microdilution susceptibility testing showed antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Streptococcus pyogenes. Dermal absorption revealed no permeation in pig skin. The quantification of the drug retained in pig skin demonstrated concentrations in the stratum corneum and epidermis, enough to treat skin infections. Moreover, in vitro cytotoxicity and micro-array analyses were performed to better understand the mechanism of action and revealed the importance of the drug as a metal ion chelator. Together, our findings suggest that disulfiram has the potential to be repurposed as an effective antibiotic to treat superficial human skin infections.

Cutibacterium acnes (C. acnes) is involved in the pathogenesis of acne by inducing inflammation and biofilm formation, along with other virulence factors. A Camellia sinensis (C. sinensis) callus lysate is proposed to reduce these effects. The aim of the present work is to study the anti-inflammatory properties of a callus extract from C. sinensis on C. acnes-stimulated human keratinocytes and the quorum-quenching activities. Keratinocytes were stimulated with thermo-inactivated pathogenic C. acnes and were treated with the herbal lysate (0.25% w/w) to evaluate its anti-inflammatory effect. C. acnes biofilm was developed in vitro and treated with 2.5 and 5% w/w of the lysate to evaluate quorum sensing and the lipase activity. The results showed that the lysate was able to reduce the production of interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and C-X-C motif chemokine ligand 1 (CXCL1), and decrease the nuclear translocation of nuclear factor kappa light chain enhancer of activated B cells (NF-κB). The lysate did not show bactericidal activity but showed diminished biofilm formation, the lipase activity, and the production of autoinducer 2 (AI-2), a member of a family of signaling molecules used in quorum sensing. Therefore, the proposed callus lysate could have the potential to reduce acne-related symptoms without the eradication of C. acnes, which is part of the natural skin microbiome.