Antiprotozoal and cytotoxic activities of Spiranthera odoratissima A. St. Hil. (Rutaceae)

Leishmaniasis and Chagas disease affects 30 million people worldwide [1]. The treatments are generally toxic or considered ineffective due to chemoresistance [2]. Plant species have been used by people in the Brazilian Cerrado for the treatment of infectious diseases [3]. In our study, eleven plant extracts of traditional medicine were tested against promastigotes of Leishmania (Leishmania) chagasi, trypomastigotes of Trypanosoma cruzi and NIH-3T3 cells of mammalian fibroblasts. Among these, the ethyl acetate extract of leaves of Spiranthera odoratissima A.St. Hil. (Rutaceae), species used traditionally in the form of decoction in wine to treat acne, boils, kidney infection and inflammation in general [4] exhibited IC50 de 56.3g/mL for T. cruzi. The chemical fractionation allowed the isolation of six compounds, among them β-sitosterol and sesamin. β-Sitosterol, a steroid-type triterpene, showed an IC50 of 92g/mL in L. (L.) chagasi, 103g/mL in T. cruzi and 312.5g/mL in NIH-3T3 cells. Sesamin, a lignin, showed an IC50 >100g/mL against both parasites. Recent studies consider safe extracts with IC50 values of mammalian cells above 250g/mL [5]. It is the first time that sesamin is isolated from this plant species.

Fig.1:β-Sitosterol

Acknowledgements: This report was supported by UnB, FAPDF, CAPES and CNPq.

References: 1. http://www.who.int/neglected_diseases/en.

2. Kumar et al. (2009) Antimicrob. Agents Chemother. 53: 835–838

3. de Mesquita et al. (2005) Bioorg. Med. Chem. 13: 4499–4506.

4. de la Cruz (1997) Cuiabá: Dissertação de Mestrado.

5. Singh et al. (2008) Parasitol. Res. 103: 351–354.