In Vitro Evaluation of the Bioactive Potential of Commercial Pepper Essential Oils

: This study analyzed five essential oils derived from plants that, despite sharing the common "pepper", belong to distinct genera and botanical families, which are increasingly recognized for their multifunctional bioactivities, including antioxidant, neuroprotective, and antimicrobial properties. In particular, five commercially available essential oils obtained from Pimenta dioica, Piper nigrum, Schinus molle, Schinus terebinthifolia, and Zanthoxylum armatum were chemically characterized and systematically evaluated for their biological potential. Gas chromatography-mass spectrometry analysis revealed distinct phytochemical profiles dominated by phenylpropanoids, monoterpenes, or oxygenated monoterpenes, which were further discriminated by multivariate statistical analysis. The essential oils were assessed in vitro for antioxidant capacity (DPPH and TEAC assays), anti-arthritic activity (protein denaturation inhibition), neuroprotective effects (acetylcholinesterase, butyrylcholinesterase, and tyrosinase inhibition), and antibiofilm activity against clinically relevant Gram-positive and Gram-negative bacteria. All oils exhibited measurable antioxidant and enzyme inhibitory activities, with P. dioica and P. nigrum showing the most balanced redox and neuroprotective profiles. Significant antibiofilm effects were observed during biofilm formation, while mature biofilms displayed strain- and oil-dependent susceptibility, highlighting differences between biomass reduction and metabolic inhibition. Overall, the results demonstrate that pepper-derived essential oils possess complementary and multi-target bioactivities strongly linked to their chemical composition, supporting their potential application as natural agents in food, pharmaceutical, and biomedical fields.