Cytotoxic effect of leaf essential oil of Lippia gracilis Schauer (Verbenaceae)

Abstract

Medicinal plants are one of the most important sources of drugs used in the pharmaceutical industry. Among traditional medicinal plants, Lippia gracilis Schauer (Verbenaceae) had been used for several medicinal purposes in Brazilian northeastern. In this study, leaf essential oil (EO) of L. gracilis was prepared using hydrodistillation. Followed by GC-MS analysis, its composition was characterized by the presence of thymol (55.50%), as major constituent. The effects of EO on cell proliferation and apoptosis induction were investigated in HepG2 cells. Furthermore, mice bearing Sarcoma 180 tumor cells were used to confirm its in vivo effectiveness. EO and its constituents (thymol, p-cymene, γ-terpinene and myrcene) displayed cytotoxicity to different tumor cell lines. EO treatment caused G1 arrest in HepG2 cells accompanied by the induction of DNA fragmentation without affecting cell membrane integrity. Cell morphology consistent with apoptosis and a remarkable activation of caspase-3 were also observed, suggesting induction of caspase-dependent apoptotic cell death. In vivo antitumor study showed tumor growth inhibition rates of 38.5-41.9%. In conclusion, the tested essential oil of L. gracilis leaves, which has thymol as its major constituent, possesses significant in vitro and in vivo antitumor activity. These data suggest that leaf essential oil of L. gracilis is a potential medicinal resource.

Antioxidant and Antiproliferative Properties of the Essential Oils of Satureja thymbra and Satureja parnassica and their Major Constituents

“…B16-F10 melanoma cells exhibited the same sensitivity to thymol in two separate studies (39). This sensitivity was higher than a third study dealing with the same cell line (37), perhaps due to different incubation times and cell viability assays. Finally, its effect on P-815, K-562, CEM and MCF-7 cell lines was diverse, with EC 50 values ranging from 0.15-0.48 μΜ (33).…”

“…Of the cell lines we examined, thymol has only previously been tested again against HepG2 cells, where its EC 50 value was estimated to be >0.1 mΜ (37). It has been studied for its activity against several cancer lines, including HL-60 acute promyelotic leukemia cells, B16-F10 cells and finally P-815, K-562, CEM and MCF-7 cell lines.…”

Biological effects of four frequently used medicinal plants of Lamiaceae

“…In animal model, Ferraz et al [99] confirmed that EO of Lippia gracilis possesses antitumor activity. Mice were subcutaneously transplanted with sarcoma 180 cells and treated by intraperitoneal route with EO for 7 days and they showed tumor growth inhibition rates of 38.5-41.9%.…”

“…Moreover, thymol was also able to induce caspase-independent apoptosis [22]. Research of Ferraz et al [99] showed cytotoxicity of Lippia gracilis EO treatment on HepG2 cells. Lippia gracilis is a medicinal plant, which has thymol as its major constituent.…”

Anticancer Activity of Essential Oils: Targeting of Protein Networks in Cancer Cells

“…Frankincense essential oil induced tumor regression in mice subcutaneously implanted with MIA PaCa-2 cells (Ni et al, 2014). Essential oil of Lippia gracilis considerably inhibited tumor growth in xenografted mice (Ferraz et al, 2013). Flavonoids isolated from Oxytropis falcata significantly inhibited tumor growth in mice transplanted with H22 cells (Yang et al, 2013).…”