# Lemongrass Essential Oil Components with Antimicrobial and Anticancer Activities
## 3 LEO Therapeutics
### Anticancer Activity

Table 5: Effects of different components of lemongrass essential oil on various cancer cell lines. diated by remodelling complexes, recruitment of Polycomb repressing complexes, and histone-modifying enzymes [97]. An involvement of non-coding RNAs (nc-RNAs) is at the basis of these mechanisms; therefore, the expression of long and small non-coding RNAs determines whether an antinocogenic pathway is repressed or downregulated, or oncogenes are set free to induce cell transformation. Therefore, chromatin accessibility (opening or compaction), access to transcription machinery, and promoter methylation are the principal mechanisms that are targeted by plant extracts, essential oils, and individual bioactives. Various classes of bioactives were shown to exert anticancer effects through the downregulation of microRNAs, most often oncomiRs, and the release of mRNAs coding for antiproliferative proteins. The review by [PERSON] [152] and that by [PERSON] [153] showed the relationship between natural compounds and nc-RNAs in cancer cells, and the potential use of their bioactives in cancer therapies. [PERSON] and colleagues described, for the first time, the involvement of pinene, one component of LEO, in the upregulation of p27/CDKN1B, a cell cycle-blocking protein, through the downregulation of miR-221 [153]. The most well-known group of nc-RNAs are microRNAs [154]. When they are abundant, they silence mRNA transcription by sequestering them and destining them to degradation. Long non-coding RNAs, such as competing endogenous RNAs (ceRNAs), may sponge a group of miRNAs and the relative abundance thereof determines whether the miRNA can exert its effects or is bound to the sponge [154]. This has been clearly reviewed for stilbenes [155] and other plant bioactives [155; 156]. It should be taken into consideration that often individual components were shown to be not effective as the essential oil, possibly because the association of multiple components potentiates the activity of each molecule. LEO effects on doxorubicin-resistant ovarian carcinoma cells were shown not dependent on citral [46]. The natural mixture of bioactives present in LEO is responsible for the beneficial effects, such as the regulation of multidrug resistance and P-glycoprotein efflux pump inhibition in human ovarian carcinoma cells [46] and colon cancer cells [157]. Furthermore, other studies showed the anticancer effect of LEO, while anticancer activity could not be attributed to its single constituents [158; 159]. The anticancer activities of plant essential oils have been usually used as a paragon to compare essential oils from different sources. For instance, zingiber essential oil (ZEO) components nerol, citral, limonene, pinene, and camphene sum to 55-60% of ZEO bioactives. ZEO was shown to be active against colorectal cancer in rats [160]. On the other hand, when specific bioactives have been studied as anticancer agents, pleiotropic effects have been observed, without precise indication of the main target or signalling pathway. For instance, resveratrol and stilbenes are known to regulate different signalling pathways [154]. The biochemical interaction with enzymes, regulation of non-coding RNAs, and activation of signalling pathways and transcription factors are among the main effects observed. In addition to essential oils, other lemongrass extracts have been tested for anticancer activity. For instance, LEO ethanolic extracts showed an anticancer effect on cancer cells, and an increased level of ROS was shown to affect the increase in apoptosis levels [159]. Although these extracts have a complex composition, some of the components may directly derive from the essential oil. Therefore, an analytical procedure is required to define these compositions and to discern whether their anticancer effects derive from one compound or the cumulative effect of several compounds.