Title : Glandora rosmarinifolia essential oil: A potential natural anticancer agent
Abstract:
Identifying, testing and implementing the use of new medicinal plants in current therapeutic protocols is a very complex, time-consuming and costly process. In many situations, the focus is on the study of plant extracts as it is known that in some cases the activity of the phytocomplex is higher than that of pure phytochemicals due to the synergism of the molecular structures. Plant secondary metabolites, including essential oils (EOs), may in fact be one of the best sources for identifying promising new therapies. Essential oils are volatile, natural complex compounds characterized by a strong odor and in nature, they play an important role in protecting plants from biotic and abiotic stresses. The biological properties of EOs are widely documented by the extensive literature demonstrating their antitumor, antibioceptive, antiviral, antiphlogistic and antimicrobial activity in vitro. Furthermore, essential oils contain different chemical classes of compounds whose heterogeneity of active parts can help prevent the development of drug resistance. Therefore, due to their low toxicity, good pharmacokinetics and multitarget action, EOs represent important alternatives to synthetic chemicals as promising drugs for use in therapy. The EO extracted from the aerial parts (branches with leaves) of Glendora rosmarinifolia (Ten.) D.C. Thomas (Boraginaceae) has been shown to possess antitumor and cytotoxic activity via a pro-oxidant mechanism in several tumor models such as hepatocellular carcinoma (HCC), triple-negative breast cancer (TNBC) and acute myeloid leukemia (AML). The chemical composition of G. rosmarinifolia EO has been identified and an isomer of hydroxy-methyl-naphthoquinone was among the most abundant compounds. Several pharmacological properties are attributed to naphthoquinones, including the ability to inhibit topoisomerases or by as catalytic inhibitors or topoisomerase II poisons. In our study conducted on an acute myeloid leukemia cell line HL-60 and its multidrug-resistant variant (MDR) HL-60R, the essential oil has shown the ability to interfere with topoisomerase II activity by inducing a G0-G1 phase cell cycle arrest, with a reduction of cells in S phase. Furthermore, the combination of EO with etoposide showed a good enhancing effect in terms of cytotoxicity in both cell lines. These results highlight the antitumor activity of EO on the HL-60 cell line and its MDR variant with a peculiar mechanism, as a Topo II modulator capable of acting as a catalytic inhibitor. Therefore, G. rosmarinifolia EO appears to be a potential anticancer drug candidate due to its cytotoxic action that is not affected by multidrug resistance. This study supports the importance of natural sources for further research in the development of drugs and in particular, the recent interest in the design of conjugation and delivery systems capable of selectively transporting natural substances even in association with traditional drugs could allow circumventing the several problems associated with current therapies such as toxicity and non-specific cell targets.
Audience Take Away Notes:
- I believe that the presentation and discussion of the anticancer action of essential oil can help the public consider these important natural sources for further research in drug development.
- Research on essential oils is on the rise and several researchers with multidisciplinary backgrounds could be involved in better defining their applications in different fields and in the design of conjugation and delivery systems.
- The use of essential oils characterized by low toxicity and often multi-target activity can overcome several problems associated with current therapies such as toxicity and non-specific cell targets.
