ABSTRACT
86Plant-derived monoterpenes (such as α-pinene, citral, limonene, or linalool) constitute a group of terpenes (also called terpenoids or isoprenoids) produced by several plant species. Among them, we mention pine fruit which contains of α-pinene (turpentine scent), (−)-limonene (scent of oranges), and bornyl acetate (camphor aroma). Furthermore, there is also orange fruit consisting of (+)-limonene (scent of oranges) and lemon fruit consisting of (+)-limonene and citral (scent of lemons). Monoterpenes are the most widespread group of naturally occurring organic chemicals being constituted by two isoprene units. These plant-derived substances are used as flavors and fragrances for the synthesis of pharmaceuticals and cosmetic products on account of their volatility. Moreover, monoterpenes show antioxidant, antimicrobial, analgesic, and anxiolytic properties. Nowadays, cancer frequency is increasing and treatments with available chemotherapeutic agents become less effective. Therefore, the search for plant products as anticancer agents has achieved great popularity. The latest in vitro and in vivo studies have proven that monoterpenes are efficient in reducing the tumor volume and tumor cell proliferation without side effects. Additionally, plant-derived monoterpenes induce autophagy and apoptosis by interfering with different intracellular signaling pathways. The available chemotherapeutic agents show lack of selectivity for tumor tissue and can be cytotoxic. New drug delivery systems are under investigation in order to produce an anticancer agent with the maximum therapeutic value. In this chapter, we focus on the chemical properties and pharmaceutical applications of the selected plant-derived monoterpenes, which are suitable candidates for these new drug delivery systems mainly due to their antiproliferative activities.
