Infrared Treatment Alters the Chemical Profile and In Vitro Bioactivity of Jojoba Oil: Antimicrobial, Biofilm Formation Inhibition and Ovarian Cancer Cell Responses

Jojoba oil (Simmondsia chinensis) is widely used in cosmetic and pharmaceutical formulations, yet approaches to enhance its biological activity remain insufficiently explored. This study investigated whether infrared (IR) treatment could modify the chemical profile and in vitro biological properties of jojoba oil. A thermal control matched to the IR temperature–time profile was included to separate bulk heating from IR-specific effects. Crude (untreated) and IR-treated oil (30 min, 50 mW/cm2) were characterized by Fourier-transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS), followed by evaluation of antimicrobial, antibiofilm, inhibition of protein denaturation, fibroblast scratch-closure, and antiproliferative activity against SK-OV-3 cells. IR treatment altered the FTIR profile and produced substantial changes in the GC-MS-detectable composition, including the detection of a peak tentatively assigned to 9-hexadecenoic acid, 9-octadecenyl ester (27.45% relative peak area), and 9-eicosyne (8.97% relative peak area); these values represent relative chromatographic abundance, not absolute concentrations. Compared with crude oil, IR-treated jojoba oil exhibited two- to fourfold lower minimum inhibitory concentrations (MIC), reaching 7.8 µg/mL against Candida albicans, and inhibited Staphylococcus aureus biofilm formation by 96.8%. It also enhanced fibroblast scratch closure (84.1% vs. 67.0%) and showed greater inhibition of protein denaturation (IC50, 4.43 vs. 6.52 µg/mL). Against SK-OV-3 ovarian cancer cells, IR-treated oil reduced the IC50 from 114.5 to 78.7 µg/mL and produced marked G0/G1 accumulation (97.9%). This response was accompanied by increased BAX (3.67-fold) and CASP3 (5.73-fold) expression and decreased BCL2 expression (0.61-fold). Collectively, these findings demonstrate that IR treatment, beyond a matched thermal control, substantially modifies jojoba oil and enhances multiple in vitro biological activities. The novelty is the linkage between IR-induced chemical alteration and functional biological changes, not the mere combination of assays.