Candida albicans is the most common human fungal pathogen, and with the increase in resistance rates worldwide, it is necessary to search for new pharmacological alternatives. Lavandula dentata L. essential oil is recognized as having antimicrobial properties. However, its effect against fungal biofilms has been poorly described. C. albicans-related infections involve the development of biofilms, which are highly resistant to conventional antifungals. In this work, we evaluated the antibiofilm effect of L. dentata L. essential oil against C. albicans. First, we characterized the essential oil by gas chromatography-mass spectrometry. The antifungal effect on C. albicans reference strains was evaluated by a disk diffusion assay and the minimal inhibitory concentration was obtained through a microdilution assay. The effect of the essential oil on the adhesion ability of C. albicans was determined through a crystal violet assay, and morphogenesis inhibition was assessed by light microscopy. The effect of the essential oil on the microarchitecture of biofilms was evaluated through scanning electron microscopy. Finally, the antibiofilm effect was evaluated through an adapted biofilm scratch assay and XTT viability assay. The main constituent of the essential oil was the monoterpenoid eucalyptol (60%). The essential oil presented minimal inhibitory concentrations of 156 and 130 µg/mL against two strains assayed. This minimal inhibitory concentration inhibited adhesion, morphogenesis, biofilm formation, altered microarchitecture, and decreased the viability of established biofilms formed on abiotic surfaces for both strains assayed. This study demonstrates that the essential oil from L. dentata could be a promising treatment against C. albicans biofilms.

Objective—To evaluate the antioxidant effects of synovial fluid (SF) pooled from metacarpophalangeal joints of healthy horses or horses with various pathological conditions, and to compare them with the antioxidant effects of hyaluronic acid (HA) and chondroitin sulfate (CS). Sample Population—SF from 1 metacarpophalangeal joint was obtained from 42 horses immediately after humane slaughter. Samples were classified into 3 groups on the basis of origin: healthy joints or joints with chronically damaged cartilage or vascularly congested synovial membranes as detected via macroscopic evaluation. Procedures—Antioxidant effects were evaluated by use of rat liver microsomal fractions treated with Fe³⁺-ascorbate as a free radical generator system leading to oxidative stress. Amounts of thiobarbituric-reactive substances and glutathione transferase (GSH-T) conjugation activity were measured. Results—SF from healthy and chronically damaged joints inhibited microsomal lipid peroxidation, whereas SF from joints with congested synovial membranes had only a slight effect. Hyaluronic acid and CS did not inhibit microsomal lipid peroxidation. Moreover, GSH-T activity was detected in all SF samples, which had similar activity regardless of disease status. All SF samples as well as HA and CS protected rat microsomal GSH-T activity against oxidative damage. Only SF samples from joints with congested synovial membranes protected microsomal thiols against oxidation, an effect also evident with HA and CS. Conclusions and Clinical Relevance—The antioxidant mechanisms associated with the response to metacarpophalangeal joint damage in horses appeared to act on different targets, depending on whether the damage was acute or chronic.

Background: Obesity is associated with insulin resistance (IR) and characterized by impaired activation of the PI3K/AKT route and glucose uptake. Elevated plasma levels of palmitic acid (PA) diminish insulin signaling in vitro and in vivo. Origanum vulgare L. essential oil (OVEO) is rich in monoterpenes with protective effects against IR. Objective: The study aimed to assess total phenols content and antioxidant activity of OVEO and its cytotoxicity, as well as its effect on insulin signaling and glucose uptake in PA-treated adipocytes. Methods: The quantification of total phenolic content was determined using the Folin–Ciocalteu method, while the antioxidant capacity of OVEO was assessed by DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) methods. The cytotoxicity of OVEO (0.1–10 µg/mL) was assessed using the MTS assay. SW872 adipocytes were incubated with 0.4 mM PA for 24 h, with or without a 2 h preincubation of OVEO, and then stimulated with insulin (100 nM, 10 min) or a vehicle. Phosphorylation of Tyr-IRS-1, Ser-AKT, and Thr-AS160 was analyzed by Western blot, and glucose uptake was measured using 2-NBDG. Results: OVEO contained phenols and exhibits antioxidant capacity. All the concentrations of OVEO assessed were not cytotoxic on SW872 adipocytes. PA decreased basal phospho-AS160 as well as insulin-stimulated phospho-IRS1, phospho-AKT, phospho-AS160 and glucose uptake, while OVEO co-treatment enhanced these markers. Conclusions: These findings suggest a beneficial effect of OVEO on the PA-impaired insulin pathway and glucose uptake, which might be explained by its phenolic content and antioxidant capacity, highlighting its potential as a complementary therapeutic agent for IR and related metabolic disorders.