Chemical Composition and Toxicity of Ocimum sanctum L. Var. Cubensis Essential Oil Up-Growing in the Eastern of Cuba

Abstract

Ocimum sanctum L. var. cubensis (OS) is a valuable medicinal plant. Some varieties have been reported and some of them remain almost unstudied. The aim of this study is therefore to evaluate the chemical composition and the in vitro/in vivo toxicity of the leaves essential oil from O. sanctum, up growing wild in the Eastern region of Cuba. The essential oil was extracted by in a Clevenger type apparatus and characterized by its chemical components helped by a Gas Chromatograph coupled to a Mass Spectrometer (GC/MS). For the evaluation of cytotoxicity, primary cultures of embryonic cardiac cells (ECC) were obtained from Swiss mice and purified, uninfected ECC cultures were exposed to compound studied at 37 ºC for 24, 48 and 72 h (up to 1200µg/mL). The cell death rates were measured by the PrestoBlue colorimetric assay. For the studies of Oral Acute Toxicity and Dermal Acute Toxicity, Sprague Dawley rats were used as biological models, fulfilling the guides 423 and 402 of the Organization for Economic Cooperation and Development and the Research Ethical Committee. The essential oil from the leaves of O. sanctum L. var. cubensis up growing wild in the eastern region of Cuba presented 20 compounds defined as the major components: Eugenol (21.96%), β-caryophyllene (20.79%) and Bicyclogermacrene (20.38%). At the maximum concentration the OS essential oil barely provokes the 5% of cell death, meaning that this substance does not result toxic for ECC at the concentration evaluated. In vivo studies also classified OS essential oil as not toxic do not showing any acute or oral toxicity (dose of 2000 mg/kg body weight). The obtained result indicates that the oil can be considered safe; harmless topically and orally showed no in vitro and in vivo toxicity studies.