Estudo do potencial antitumoral do óleo essencial das folhas da Eplingiella fruticosa

Abstract

Introduction: Cancer is a disease that has high rates of incidence and mortality worldwide. Despite significant efforts to develop new therapeutic intervention approaches, the rate of failure remains high. Medicinal plants are one of the most important sources of drugs for the pharmaceutical industry. In this context, Eplingiella fruticosa (Lamiaceae) or "alecrim do tabuleiro" deserves attention in antitumor research, especially because many species in the family have shown relevant antitumor effects. Objective: Therefore, for the first time, the antitumor potential of the essential oil from the leaves of Eplingiella fruticosa (OEEF) was investigated in vitro and in vivo, and possible toxicological effects were evaluated. Methods: OEEF was obtained through hydrodistillation, and gas chromatography-mass spectrometry (GC-MS) was used to characterize its chemical composition. The cytotoxic activity of OEEF was investigated using the MTT assay. The murine Sarcoma 180 tumor model was used to evaluate in vivo antitumor activity and the toxicity of OEEF (25, 50, and 100 mg/kg) after seven days of intraperitoneal treatment. The OEEF toxicity study included the evaluation of possible changes in body and visceral mass, as well as the counting of leukocytes and erythrocytes in blood collected from mice. Furthermore, biochemical analysis of blood serum and tumor and visceral histology in mice were performed. Results: 80 compounds were identified in OEEF, with 21 considered major, including 1,8-cineole (17.07%), Camphor (9.36%), β-caryophyllene (8.96%), and α-pinene (6.97%). In the cytotoxicity test against human tumor cell lines, OEEF exhibited a growth inhibition percentage (GIP) ranging from 89.3 to 94.8%. The half-maximal inhibitory concentration (IC50) was in the range of 0.002, 0.260, and 0.218 µg/mL for Colon Carcinoma (HCT-116), Glioblastoma (SNB-19), and Prostate Carcinoma (PC-3), respectively. Tumor growth inhibition rates were 91.2%, 87.7%, and 13% for OEEF treatment at doses of 25, 50, and 100 mg/kg/day, respectively. 5-FU (25 mg/kg/day) showed a 93.4% inhibition compared to the control group, and the OEEF25 and OEEF50 groups were statistically similar to it. OEEF25 treatment did not cause changes in body and visceral mass; however, there was a decrease in heart mass in the OEEF50 and OEEF100 groups and in body mass in the OEEF100 and 5-FU groups. Thrombocytopenia (OEEF50, OEEF100, and 5-FU); lymphocytosis (OEEF50 and OEEF100), and leukopenia (5-FU) were identified. Histological results of the tumors in the OEEF100 and CTRL groups were indistinguishable. In the OEEF25 and OEEF50 groups, lower necrosis and mitotic activity indices were observed. Histological evaluation of the spleen was consistent with a reduction in white pulp in the 5-FU group, while heart and liver analysis was consistent with normal tissue cytology in the groups. Conclusion: Treatment with lower doses of OEEF showed significant antitumor potential without evidence of toxicity in the parameters evaluated, particularly with regard to OEEF25.