Cosmetics

Essential oils are widely used in cosmetic products and are valued for their antimicrobial properties. In this study, the in vitro antimicrobial activity of five pure essential oils (EOs) and five commercially available EO blends was comparatively evaluated against six skin-associated pathogens: Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa, Candida lusitaniae and Candida guilliermondii. Chemical profiling of volatile constituents was performed using gas chromatography–mass spectrometry; antimicrobial activity was assessed by broth microdilution to determine minimum inhibitory concentration (MIC), as well as spot-inoculation to determine minimum bactericidal concentration (MBC). Results revealed microorganism-dependent inhibitory and bactericidal activity of the tested essential oils. Candida spp. and E. coli were the most susceptible microorganisms, whereas P. aeruginosa exhibited the lowest susceptibility to essential oils. Pinus sylvestris showed comparatively lower MIC and MBC values across most tested microorganisms. Commercial EO blends showed comparable antimicrobial activity to individual essential oils. Overall, this study provides a comparative in vitro screening of selected essential oils and commercial blends relevant to cosmetic applications, indicating that EO blends do not exhibit superior antimicrobial activity over pure oils under the tested conditions.

Androgenetic alopecia (AGA) and telogen effluvium (TE) are common hair loss disorders characterized by dysregulated hair follicle cycling and impaired dermal papilla cell function. Emerging evidence indicates that exosomes are key mediators of intercellular communication, largely through their microRNA (miRNA) cargo. Milk-derived exosomes (Mi-Exos) represent an accessible and biologically active source of regulatory miRNAs with potential relevance for hair disorders. This study evaluated the in vitro effects of bovine milk-derived exosomes (MEV-miRNAs) on human hair follicles. MEV-miRNAs were enriched in miRNA families (Let-7, miR-21, miR-30, miR-200, and miR-148/152) previously implicated in hair follicle regulation. Viability/metabolic activity of hair follicle dermal papilla (HFDP) cells was assessed, and human hair follicles were cultured ex vivo to measure shaft elongation and modulation of the WNT signaling pathway by qRT-PCR. MEV-miRNAs significantly increased HFDP cell viability after 24 h compared with controls. Human hair follicles showed a non-significant trend toward increased elongation following treatment. Gene expression analysis revealed significant up-regulation of key WNT pathway components, including WNT2, WNT5B, WNT10A, WNT11, MMP7, WISP1, and NKD1, indicating modulation of WNT-associated pathways implicated in hair follicle growth and cycling. Overall, MEV-miRNAs exhibit positive modulatory effects on signaling pathways, supporting their potential as a novel therapeutic strategy for AGA and TE.

Oily skin is a prevalent dermatological condition characterized by excessive sebum production, due to hyperactivity of the sebaceous glands. In this study, a randomized split-face clinical trial was conducted on 22 subjects with combination to oily skin to evaluate the efficacy of a cosmetic cream containing a standardized amount of isorhamnetin extract from prickly pear (Opuntia ficus-indica), applied twice daily over a 28-day period. Efficacy assessments included instrumental measurements of skin sebum content, Sebum Excretion Rate (SER), pore size, tumor necrosis factor-alpha (TNF-α) levels, skin microbiome composition, and lipid profile. Additionally, the study included an assessment of participants’ subjective perception. After 14 and 28 days of product use, respectively, a significant reduction in skin sebum content was observed, with decreases of 13.1% and 21.1% on the forehead, and 10.4% and 15.8% in the alar groove. This reduction in sebum levels was associated with a mattifying effect lasting up to 7.1 h, a 37.2% decrease in the sebum excretion rate (SER), and a 9.6% reduction in pore size. The TNF- α levels decreased by 7.4%. The extract was well tolerated by the skin microbiome, which remained stable. Additionally, analysis of the skin lipid profile revealed an increase in both ceramide and triacylglycerol levels. Overall, our findings demonstrate the role of the extract in modulating sebaceous gland activity, improving skin appearance, reducing inflammation, and supporting barrier integrity and hydration in individuals with oily skin.