Hindawi Publishing Corporation Evidence-Based Complementary and Alternative Medicine Volume 2013, Article ID 856168, 11 pages http://dx.doi.org/10.1155/2013/856168 Research Article Repeated-Doses Toxicity Study of the Essential Oil of Hyptis martiusii Benth. (Lamiaceae) in Swiss Mice Germana Freire Rocha Caldas, 1 Alice Valença Araújo, 2 Giwellington Silva Albuquerque, 3 Jacinto da Costa Silva-Neto, 3 João Henrique Costa-Silva, 4 Irwin Rose Alencar de Menezes, 5 Ana Cristina Lima Leite, 1 José Galberto Martins da Costa, 5 and Almir Gonçalves Wanderley 1,2 1 Department of Pharmaceutical Sciences, Federal University of Pernambuco, 50740-521 Recife, PE, Brazil 2 Department of Physiology and Pharmacology, Federal University of Pernambuco, 50670-901 Recife, PE, Brazil 3 Department of Histology and Embryology, Federal University of Pernambuco, 50670-901 Recife, PE, Brazil 4 Department of Physical Education and Sport Sciences, Federal University of Pernambuco, Vit´ oria de Santo Ant˜ ao, 55608-680 Recife, PE, Brazil 5 Department of Biological Chemistry, Regional University of Cariri, 63105-000 Crato, CE, Brazil Correspondence should be addressed to Almir Gonc ¸alves Wanderley; almirgw@globo.com Received 16 June 2013; Revised 29 July 2013; Accepted 29 July 2013 Academic Editor: Evan Paul Cherniack Copyright © 2013 Germana Freire Rocha Caldas et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Hyptis martiusii Benth. (Lamiaceae) is found in abundance in Northeastern Brazil where it is used in traditional medicine to treat gastric disorders. Since there are no studies reporting the toxicity and safety profle of this species, we investigated repeated- doses toxicity of the essential oil of Hyptis martiusii (EOHM). Swiss mice of both sexes were orally treated with EOHM (100 and 500mg/kg) for 30 days, and biochemical, hematological, and morphological parameters were determined. No toxicity signs or deaths were recorded during the treatment with EOHM. Te body weight gain was not afected, but there was an occasional variation in water and food consumption among mice of both sexes treated with both doses. Te hematological and biochemical profles did not show signifcant diferences except for a decrease in the MCV and an increase in albumin, but these variations are within the limits described for the species. Te microscopic analysis showed changes in liver, kidneys, lungs, and spleen; however, these changes do not have clinical relevance since they varied among the groups, including the control group. Te results indicate that the treatment of repeated-doses with the essential oil of Hyptis martiusii showed low toxicity in mice. 1. Introduction Te genus Hyptis (Lamiaceae), comprising approximately 400 species distributed across a wide area from Southern United States to Argentina, has been widely studied from an ethnopharmacological, pharmacological, and chemical point of view, mainly owing to the diversity of bioactive con- stituents found in essential oils and extracts, which have inter- esting biological efects such as antimicrobial, anticancer, and insecticidal properties [1]. Some species of the Hyptis genus, such as Hyptis suaveolens, Hyptis pectinata, Hyptis crenata, and Hyptis fruticosa, are characterized by the presence of essential oils with important biological activities such as antiseptic [2], antifungal [3], antibacterial [4], anti-infam- matory [5], antinociceptive [6], and antiulcer properties [7, 8] among others. Hyptis martiusii Benth., commonly known as “cidreira- do-campo” or “cidreira-brava,” is an aromatic plant found in abundance in Northeastern Brazil and is characterized as a potential source of essential oils, like other species of the Hyptis genus. In folk medicine, the infusion or decoction of Hyptis martiusii leaves is used to combat intestinal and stomach diseases, while the decoction of the roots is used to counter infammation of the ovaries [9]. Few studies have been carried out into the biological and pharmacological properties of Hyptis martiusii. Cytotoxic and antiproliferative