Gentisic acid (2,5-dihydroxybenzoic acid) is primarily found naturally in plants and has demonstrated a significant range of biological activities; however, its efficacy and safety as a topical application ingredient are not yet well established. Thus, the compound’s potential antioxidant and antimicrobial properties were evaluated for efficacy, while the cytotoxicity was evaluated for safety. The antioxidant activity, measured by the DPPH kinetic method, showed an Efficiency Concentration (EC₅₀) of 0.09 with an antioxidant reducing power (ARP) of 11.1. The minimum inhibitory concentration (MIC) against Staphylococcus aureus was 4.15 mg/mL, Escherichia coli was 4.00 mg/mL, Candida albicans was 3.00 mg/mL, and Cutibacterium acnes was 3.60 mg/mL, and the MIC for C. acnes has remained unpublished until now. The substance showed low cytotoxicity by the neutral red uptake (NRU) methodology against HaCat, HDFa, and HepG2 cells at concentrations of up to 10.0, 7.3, and 4.0 mM, respectively, also representing unpublished data. This evidence demonstrates gentisic acid as a promising active substance for skin topical application in the cosmetic or pharmaceutical industry.

Ticks pose significant challenges to public and veterinary health, acting as vectors of several diseases that affect animals and humans. Traditional chemical control methods, such as pyrethroids and organophosphates, have led to increasing resistance and environmental contamination, highlighting the need and urgency for alternative strategies. This review explores contemporary approaches to tick control, emphasizing plant-derived acaricides and their integration with nanotechnology. Plant extracts, known for their acaricidal properties, disrupt several biological processes in ticks, reducing reproduction and survival rates. The advent of nanotechnology offers promising advances in increasing the efficacy of these natural extracts. Nanoparticles add properties to the systems where they act by improving the stability, bioavailability, and targeted delivery of plant-derived compounds, potentially overcoming the limitations of traditional acaricides. This synthesis of current knowledge highlights the potential of combining plant extracts with nanotechnology to develop sustainable and effective tick control solutions, addressing issues of acaricide resistance as well as environmental concerns. The review also identifies research gaps and suggests directions for future studies to optimize the application of nanotechnology in tick management.

Fungal infections, including skin ones, due to resistant strains combined with the gap in discovering new antifungal compounds have presented great medical importance; thus, we evaluated the antifungal properties of Plinia cauliflora, a Brazilian plant known as jabuticabeira, as its fruits have been used in traditional medicine, which has been scientifically proved. The differential in this study was the use of leaves to obtain the ethanolic extract and its fractions and with incorporation in microemulsions that can increase the activity, promoting greater availability of active components in therapeutic targets. Candida glabrata has been very prominent in nosocomial infections and our results were very promising, showing a minimum inhibitory concentration of 4.88 μg/mL for the extract and about a 4-fold decrease with its microemulsion reaching 1.22 μg/mL; for the dermatophytic fungus Trichophyton rubrum, this decreased 2-fold, from 156.25 μg/mL to 78.12 μg/mL. The antioxidant activity was also studied, showing the best results for the extract at 25.6 μg/mL and lastly, the samples were not toxic when the Galleria mellonella model was used. Thus, the results demonstrate the activity of the extract, and that the incorporation was able to increase the antifungal activity in a safe, non-toxic manner, making it possible to provide a therapeutic option for these fluconazole-resistant microorganisms.

Physalis angulata L. is a source of lipophilic bioactive metabolites of interest for cosmetic research, but the antifungal behavior of its fractions in nanoemulsions remains poorly characterized. This study evaluated the antioxidant, antifungal, irritant, and cytotoxic activity of a chloroform extract (E) and a hexane–ethyl acetate (6:4) fraction (F) from P. angulata, and their nanoemulsions (NE-E, NE-F), using HPLC-UV, DPPH, microdilution, HET-CAM and HaCaT assays. HPLC-UV showed major peaks at 39–41 min, predominant in F. E showed moderate antioxidant activity (EC₅₀ = 415 µg/mL), while F showed limited activity. F was active against all six microorganisms tested (T. rubrum, T. mentagrophytes, M. canis, C. albicans, C. krusei, C. parapsilosis), most potently against M. canis (MIC = 0.07 mg/mL). NE-F retained reduced activity against the dermatophytes but not against Candida. Samples showed no HET-CAM irritant effect. In HaCaT cells, NE-F showed an IC₅₀ of 173.1 µg/mL; its MIC against M. canis (310 µg/mL) exceeded this value, indicating a limited cellular safety margin. The nanoemulsions remained in the nanometric range over 30 days, although NE-F showed a transient increase in PDI on Day 7. These results demonstrate the antifungal potential of fraction F and show that nanoemulsification partially preserved dermatophyte activity, supporting further investigation of F as a candidate cosmetic ingredient.