Evidence-Based Complementary and Alternative Medicine the biological potential of plant extracts. Several natural compounds, particularly substances with antitumoral, anti- microbial, insecticidal, and antitrypanosomal activity, have been tested through these bioassays showing signiﬁcant correlation [36]. The results showed that the extract of A. hispidum pre- sented LC50 = 4.101 µg/mL, S. brasiliensis LC50 = 428 µg/mL, and X. americana LC50 = 4.262. Meyer et al. [28] described a lethal concentration (LC50) based on the toxicity of substances to the larvae of A. salina. According to the scale, LC50 values < 500 µg·mL−1 indicate toxicity, LC50 between 500 and 1000 µg·mL−1 denote moderate toxicity, while LC50 > 1000 µg·mL−1 suggest lack of toxicity. In this work S. brasiliensis showed data that indicate toxi- city. The study conducted by de Barros et al. [15] conﬁrms the possible plant toxicity. It was related that this can be explained by the high concentration of polyphenols (tannin, ﬂavonoids, and other phenolics compounds) present in this plant and which are well known for their toxicity against A. salina. 4. Conclusion Plant samples tested in this study exhibited good antibioﬁlm activity for the treatment of oral problems. The S. brasiliensis showed higher activity for P. aeruginosa and S. aureus, but toxicity against Artemia salina. The result suggests that stud- ies to isolate and characterize the antibioﬁlm compounds of S. brasiliensis Engl, whereas their high antibacterial activity could be the base of development of new phytotherapic product with broad spectra. Studies in vivo of toxicity are essential. This reinforces the concept that the ethnobotanical inves- tigation of used plants is necessary since it will reveal a great number of positive responses in in vitro tests. Acknowledgment The authors are grateful to Fundac¸ a˜o de Apoio a` Pesquisa do Estado da Para´ıba (FAPESQ) for ﬁnancial aid and to Fundac¸ a˜o Oswaldo Cruz that donated the ATTC strains. References [1] G. More, T. E. Tshikalange, N. Lall, F. Botha, and J. J. M. Meyer, “Antimicrobial activity of medicinal plants against oral microorganisms,” Journal of Ethnopharmacology, vol. 119, no. 3, pp. 473–477, 2008. [2] N. S. Soukos and J. M. Goodson, “Photodynamic therapy in the control of oral bioﬁlms,” Periodontology 2000, vol. 55, no. 1, pp. 143–166, 2011. [3] B. Ncube, J. F. Finnie, and J. van Staden, “In vitro antimicro- bial synergism within plant extract combinations from three South African medicinal bulbs,” Journal of Ethnopharmacol- ogy, vol. 139, no. 1, pp. 81–89, 2012. [4] S. L. Cartaxo, M. M. de Almeida Souza, and U. P. de Al- buquerque, “Medicinal plants with bioprospecting potential used in semi-arid northeastern Brazil,” Journal of Ethnophar- macology, vol. 131, no. 2, pp. 326–342, 2010. 5 [5] M. F. Agra, G. S. Baracho, K. Nurit, I. J. L. D. Bas´ılio, and V. P. M. Coelho, “Medicinal and poisonous diversity of the ﬂora of “Cariri Paraibano”, Brazil,” Journal of Ethnopharmacology, vol. 111, no. 2, pp. 383–395, 2007. [6] M. D. F. Agra, K. N. Silva, I. J. L. D. Bas´ılio, P. F. De Freitas, and J. M. Barbosa-Filho, “Survey of medicinal plants used in the region Northeast of Brazil,” Brazilian Journal of Pharma- cognosy, vol. 18, no. 3, pp. 472–508, 2008. [7] G. F. Scarpa, “Medicinal plants used by the Criollos of North- western Argentine Chaco,” Journal of Ethnopharmacology, vol. 91, no. 1, pp. 115–135, 2004. [8] A. Asase, A. A. Oteng-Yeboah, G. T. Odamtten, and M. S. J. Simmonds, “Ethnobotanical study of some Ghanaian anti- malarial plants,” Journal of Ethnopharmacology, vol. 99, no. 2, pp. 273–279, 2005. [9] B. G. Brasileiro, V. R. Pizziolo, D. S. Raslan, C. M. Jamal, and D. Silveira, “Antimicrobial and cytotoxic activities screening of some Brazilian medicinal plants used in Governador Valadares district,” Brazilian Journal of Pharmaceutical Sciences, vol. 42, no. 2, pp. 195–202, 2006. [10] U. P. de Albuquerque, P. M. de Medeiros, A. L. S. de Almeida et al., “Medicinal plants of the caatinga (semi-arid) vegetation of NE Brazil: a quantitative approach,” Journal of Ethnopharmacology, vol. 114, no. 3, pp. 325–354, 2007. [11] P. Nadembega, J. I. Boussim, J. B. Nikiema, F. Poli, and F. Antognoni, “Medicinal plants in Baskoure, Kourittenga Province, Burkina Faso: an ethnobotanical study,” Journal of Ethnopharmacology, vol. 133, no. 2, pp. 378–395, 2011. [12] O. V. Sousa, G. Del-Vechio-Vieira, and M. A. C. Kaplan, “Anal- gesic and anti-inﬂammatory properties of Annona coriacea Mart. (Annonaceae) leaves methanol extract,” Latin American Journal of Pharmacy, vol. 26, no. 6, pp. 872–877, 2007. [13] C. A. T. Siqueira, J. Oliani, A. Sartoratto et al., “Chemical constituents of the volatile oil from leaves of Annona coriacea and in vitro antiprotozoal activity,” Brazilian Journal of Pharmacognosy, vol. 21, no. 1, pp. 33–40, 2011. [14] M. E. Goleniowski, G. A. Bongiovanni, L. Palacio, C. O. Nun˜ez, and J. J. Cantero, “Medicinal plants from the “Sierra de Comechingones”, Argentina,” Journal of Ethnopharmacology, vol. 107, no. 3, pp. 324–341, 2006. [15] F. M. C. de Barros, K. N. Pereira, G. D. Zanetti, and B. M. Heinzmann, “Medicinal plants used by people from Sa˜o Luiz Gonzaga, RS, Brazil,” Latin American Journal of Pharmacy, vol. 26, no. 5, pp. 652–662, 2007. [16] D. Q. Falca˜o and F. S. Menezes, “Revisa˜o etnofarmacolo´ gica, farmacolo´ gica e qu´ımica do geˆnero Hyptis,” Revista Brasileira Farma´cia, vol. 84, no. 3, pp. 69–74, 2003. [17] M. Coelho-Ferreira, “Medicinal knowledge and plant utiliza- tion in an Amazonian coastal community of Marud a´, Para´ State (Brazil),” Journal of Ethnopharmacology, vol. 126, no. 1, pp. 159–175, 2009. [18] J. Sanz-Biset, J. Campos-de-la-Cruz, M. A. Epiquie´n-Rivera, and S. Can˜igueral, “A ﬁrst survey on the medicinal plants of the Chazuta valley (Peruvian Amazon),” Journal of Ethnophar- macology, vol. 122, no. 2, pp. 333–362, 2009. [19] M. de Fa´tima Agra, P. F. de Freitas, and J. M. Barbosa-Filho, “Synopsis of the plants known as medicinal and poisonous in Northeast of Brazil,” Brazilian Journal of Pharmacognosy, vol. 17, no. 1, pp. 114–140, 2007. [20] U. P. de Albuquerque, “Re-examining hypotheses concerning the use and knowledge of medicinal plants: a study in the Caatinga vegetation of NE Brazil,” Journal of Ethnobiology and Ethnomedicine, vol. 2, article 30, pp. 1–10, 2006.