\ SHORT COMMUNICATION Salvia connivens, a Source of Bioactive Flavones with Amoebicidal and Giardicidal Activity Elihú Bautista 1 & Fernando Calzada 2 & Lilian Yépez-Mulia 3 & Brenda Y. Bedolla-García 4 & Mabel Fragoso-Serrano 5 & Guillermo Pastor-Palacios 1 & Daphne E. González-Juárez 1 Received: 14 July 2020 /Accepted: 9 September 2020 # Sociedade Brasileira de Farmacognosia 2020 Abstract Salvia connivens Epling, Lamiaceae, is an annual herbaceous plant used as a traditional medicine in Mexico for the treatment of diarrhea, which out can be caused by bacterial, viral, and protozoal infections, as well as toxins mainly. Mexican medicinal plants with anti-diarrheic activity represent a source of potential antiprotozoal agents. The phytochemical isolation of the constituents of an acetone-soluble extract led to the isolation of the known flavonoids: eupatorin, cirsiliol, and nuchensin. The structures of these compounds were elucidated by the analysis of their NMR and MS data. Nuchensin displayed potent antiprotozoal activity against Entamoeba histolytica (IC 50 0.072 ± 0.006 μM) and Giardia lamblia (IC 50 0.118 ± 0.006 μM), which was comparable to metronidazole. Keywords Flavones . Salvia species . Antiamoebic activity . Antigiardial activity Introduction Entamoeba histolytica and Giardia lamblia are two protozoa that produce enteric infections with the common symptom of dysentery and acute diarrhea, which out constitute a serious public health problem in tropical regions around the globe, and are considered endemic in several countries of the African, American, and Asian continents (Marie and Petri 2014; Saidin et al. 2019). Annually, each protozoan causes 50 and 280 million of cases respectively, and 100,000 deaths, being mainly affecting children younger than 10 years old (Rojas et al. 2016 ; Quihui-Cota et al. 2017; Ibañez- Cervantes et al. 2018). The treatment of these kinds of infec- tions is based on the use of synthetic antiprotozoal agents such as metronidazole, nitazoxanide, and tinidazole; however, these drugs have several adverse effects, as well as possible risks of carcinogenesis and mutagenesis with the use of met- ronidazole (Hayat et al. 2016). In addition, these drugs many times are often not available in geographically isolated com- munities where the health services are scarce, limiting the treatment of amoebiasis and giardiasis; instead, the ingestion of infusions made with local plants surrounding these Electronic supplementary material The online version of this article (https://doi.org/10.1007/s43450-020-00103-8) contains supplementary material, which is available to authorized users. * Elihú Bautista francisco.bautista@ipicyt.edu.mx * Fernando Calzada fernando.calzada@imss.gob.mx 1 Consejo Nacional de Ciencia y Tecnología-Consorcio de Investigación, Innovación y Desarrollo para las Zonas Áridas, Instituto Potosino de Investigación Científica y Tecnológica A.C., San Luis Potosí, Mexico 2 Unidad de Investigación Médica en Farmacología, Unidad Médica de Alta Especialidad, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, Mexico City, Mexico 3 Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Unidad Médica de Alta Especialidad, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Mexico City, Mexico 4 Insituto de Ecología A.C., Centro Regional Bajío, Pátzcuaro, Michoacán, Mexico 5 Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, Mexico https://doi.org/10.1007/s43450-020-00103-8 / Published online: 24 September 2020 Revista Brasileira de Farmacognosia (2020) 30:729–732