IN VIVO TOXICOLOGICAL EVALUATION OF Lavandula dentata ESSENTIAL OIL FROM DIFFERENT REGIONS OF RIO GRANDE DO SUL, BRAZIL

Resumo

INTRODUCTION: Essential oils (EO) are volatile liquids composed of low molecular weight odorous substances, widely used in aromatherapy for therapeutic purposes. Among them, the EO obtained from Lavandula angustifolia, a species native to Europe, stands out for its anxiolytic properties, attributed to the presence of linalool. In Brazil, Lavandula dentata has been used with the same purpose, although its efficacy and safety still require scientific validation. Considering the growing use of this species and the fact that its chemical composition may vary depending on cultivation conditions, it is essential to evaluate the chemical profile and safety of these EOs, particularly due to the presence of 1,8-cineole, a potentially toxic compound. OBJECTIVE: To identify L. dentata EOs with the highest concentrations of linalool and 1,8-cineole and to evaluate the acute oral toxicity of these EOs in Balb/C mice. MATERIAL AND METHODS: The EOs analyzed were provided by farmers from Serra Gaúcha, cultivated in Santa Cruz do Sul (SCS), Morro Reuter (MR), and Nova Petrópolis (NP). The choice of EOs for toxicity evaluation was based on chemical composition analysis, with SCS EO presenting the highest linalool content (28.86 mg/ml), and MR EO showing the highest 1,8-cineole content (390.20 mg/ml). Acute toxicity assessment followed OECD Guideline 423, with a single oral dose administration, approved by CEUA-Feevale (01.24.131). Female mice (25–30 g) from the Animal Facility of Feevale University were used, respecting animal welfare regulations. The dose of 2000 mg/kg was initially administered to three mice per group: negative control, SCS EO, and MR EO. The animals were monitored for 14 days regarding feed consumption and body weight variation, and the test was repeated for limit testing (n=3). RESULTS AND CONCLUSION: In the first hours after administration, animals exposed to the EOs showed transient signs such as agitation, spasms, and incoordination. However, during the observation period, no significant changes in body weight or feed consumption were observed. These findings indicate that, despite the presence of 1,8-cineole, the L. dentata EOs evaluated did not demonstrate acute oral toxicity under the tested conditions.