Exploring the anticancer potential of Citrus spp. essential oils against various human cancer cell lines

Abstract

Conventional cancer treatments, such as chemotherapy and radiotherapy, remain the mainstay of therapy but are often associated with severe toxicity and a diminished quality of life for patients. These limitations have increased interest in natural products as sources of novel anticancer compounds and potential adjunctive leads for future development. Natural compounds, particularly those derived from plants, have historically contributed significantly to anticancer drug discovery, with nearly 60% of approved agents originating from natural sources. Among medicinal plants, the Citrus genus has attracted considerable attention for its diverse range of bioactive metabolites, including flavonoids, limonoids, coumarins, and essential oils. Citrus essential oils are particularly rich in monoterpenes, such as d-limonene, β-pinene, and myrcene, which exhibit potent cytotoxic, antiproliferative, and pro-apoptotic effects against various human cancer cell lines. Emerging evidence suggests that these compounds can modulate multiple molecular targets involved in apoptosis, oxidative stress, and tumor progression, suggesting promising bioactivity and mechanistic relevance with potential for future therapeutic development. This review provides an updated and critical overview of the chemical composition, extraction methods, and anticancer mechanisms of Citrus essential oils, with particular emphasis on their molecular modes of action and their prospects for future translational and therapeutic research.