Potencial antitumoral de espécies de Lippia (Verbenaceae) do Estado da Bahia

Abstract

Lippia (Verbenaceae) is a plant genus distributed throughout all Southern and Central America, and Tropical Africa. Approximately 60 species are endemic in Brazil and 22 are endemic in the state of Bahia. Lippia has a long history of use in traditional medicine, the most common use being in the treatment of respiratory diseases. Despite Lippia’s extensive history in treating diseases, little is known about its anticancer properties against brain and central nervous system tumors. This paper explores the anticancer potential of 5 species of Lippia from the state of Bahia (Brazil),Lippia alnifolia, Lippia insignis, Lippia lasiocalycina, Lippia origanoides and Lippia thymoides. To assess the cell viability of essential oils and methanol extracts derived from these species MTT assay was utilized. To assess the effects of the essential oils and methanol extracts on morphology of cancer cells a Nikon Ts-100 phase contrast microscope was used, and photos were taken with a Nikon E4300. All essential oils were evaluated at 0.1 mg.mL-1, 0.3 mg.mL-1, 0.5 mg.mL-1, and 1 mg.mL-1. All methanol extracts were evaluated at 1 µg.mL-1, 10 µg.mL-1, 100 µg.mL-1, 500 µg.mL-1, and 1000 µg.mL-1. The ability to inhibit cell migration was assessed by wound heal assay. All methanol extracts were evaluated at 500 µg.mL-1. All essential oils were evaluated at 0.1 mg.mL-1. To access the effects of essential oils and methanol extracts on the cell cycle flow cytometry was used. All methanol extracts were evaluated at 1000 µg.mL-1. All essential oils were evaluated at 0.03 mg.mL-1. The essential oils derived from Lippia alnifolia, Lippia insignis, Lippia lasiocalycina, and Lippia origanoides all drastically decreased the cell viability of the C6 cell line in a concentration dependent manner. The essential oil derived from Lippia thymoides increased cell viability in a concentration dependent manner. All of the methanol extracts appear to have the ability to abruptly decrease cell viability at either 500 µg.mL-1 or 1000 µg.mL-1 it. Lippia alnifolia and Lippia insignis both have the ability to significantly alter the morphology of the C6 cell line. Methanol extracts derived from Lippia alnifolia, Lippia insignis, Lippia lasiocalycina, Lippia origanoides and Lippia thymoides all significantly inhibit the migration of C6 cells at a concentration of 500 μg.mL-1. Essential oils obtained from Lippia alnifolia, Lippia insignis, Lippia lasiocalycina, Lippia origanoides and Lippia thymoides significantly inhibited the migration of C6 cells at a concentration of 0.1 mg.mL-1. All methanol extracts and essential oils tested demonstrated the ability to induce some degree of nuclear fragmentation, vacuolization, and cytoplasmic swelling. These results indicate that the constituents of both the essential oils and methanol extracts should be isolated and their anticancer potential should be further explored.