Pimenta dioica (Allspice): An integrated review of botanical characteristics, phytochemical diversity, pharmacological activities, and industrial relevance

Allspice (Pimenta dioica [L.] Merr.), a dioecious evergreen tree of the family Myrtaceae, represents one of the most economically and pharmacologically significant spice crops native to the Neotropical region. Renowned for its unique aromatic profile that integrates sensory notes reminiscent of clove, cinnamon, and nutmeg, the species has gained increasing global relevance beyond culinary applications. This review synthesizes and critically evaluates contemporary literature on the botany, phytochemistry, pharmacology, cultivation, and industrial applications of P. dioica. Taxonomically, the species displays a complex reproductive system characterized by functional dioecy, posing distinct challenges for commercial propagation and orchard productivity. Phytochemical investigations consistently identify eugenol, methyl eugenol, and β-caryophyllene as dominant constituents of the essential oil, accompanied by diverse polyphenols and flavonoids that collectively underpin its multifunctional bioactivity. Pharmacological evidence highlights strong antibacterial, antifungal, antioxidant, anti-inflammatory, and anticancer properties, mediated through mechanisms including membrane destabilization, quorum-sensing inhibition, mitochondrial depolarization, autophagy induction, and modulation of NF-κB pathways. In parallel, agronomic studies emphasize the importance of optimized propagation techniques, nutrient management, disease surveillance particularly for Austropuccinia psidii (myrtle rust) and post-harvest drying systems to ensure high-quality spice and essential oil yields. Industrially, P. dioica is emerging as a high-value ingredient in food preservation, active packaging, perfumery, cosmetics, and botanical biopesticide formulations. Despite its wide-ranging utility, significant knowledge gaps remain regarding genetic improvement, standardization of chemotypes, resistance breeding, and clinical validation of therapeutic benefits. Addressing these gaps through genomics-assisted breeding, metabolomics, and translational medical research is essential for unlocking the full commercial and biomedical potential of this underutilized yet highly promising tropical species.