Bioactivities of essential oils from different parts of Spiranthera odoratissima (Rutaceae)

Abstract

Abstract This paper aims to investigate, for the first time, in vitro antitubercular, antileishmanial and antiproliferative activities of essential oils (EOs) from S. odoratissima leaves and flowers - grown in midwestern Brazil - against Mycobacterium tuberculosis, promastigote forms of Leishmania amazonensis and human tumor cell lines. Antimycobacterial activity of EOs was evaluated in terms of the minimal inhibitory concentration (MIC). EOs from leaves and flowers showed to be active antimicrobials against M. tuberculosis, since MIC values were 150 µg/mL and 162.5 µg/mL, respectively. Both EOs exhibited significant activity against promastigote forms of L. amazonensis; IC50 values (50% growth inhibition) were 14.36 ± 2.02 (EOs from leaves) and 19.89 ± 2.66 µg/mL (EOs from flowers). Antiproliferative activity in normal (GM07492A, lung fibroblasts) and tumor (MCF-7, HeLa and M059J) cell lines was performed by the XTT assay; results were expressed as IC50 (50% cell growth inhibition) and the selective index was calculated. IC50 values of EOs from leaves and flowers obtained in normal cell lines for were 502.97 ± 40.33 µg/mL and 370.60 ± 2.01 µg/mL, respectively. Antiproliferative activity was observed against human tumor cell lines, whose IC50 values were significantly lower than those obtained in normal cell lines of MCF-7 cells (367.57 ± 4.46 µg/mL-EOs from leaves and 357.70 ± 1.85 µg/mL-EOs from flowers) and M059J cells (492.53 ± 56.67 µg/mL-EOs from leaves and 324.90 ± 6.72 µg/mL-EOs from flowers), thus, indicating selectivity. These in vitro results showed that EOs from S. odoratissima may be an antimycobacterial, antiparasitic and antitumor agent.