Research Article Bioactivities of Flavonoids from Lopezia racemosa Enrique Vergara Barragán, 1 Horacio Bach , 2 Socorro Meza-Reyes, 1 Sara Montiel-Smith, 1 Eugenio Sánchez-Arreola , 3 and Luis Ricardo Hernández 3 1 Facultad de Ciencias Qu´ ımicas, Benem´ erita Universidad Aut´ onoma de Puebla, Mexico 2 Faculty of Medicine, Department of Infectious Diseases, University of British Columbia, Vancouver, BC, Canada 3 Departamento de Ciencias Qu´ ımico Biol´ ogicas, Universidad de las Am´ ericas Puebla, Mexico Correspondence should be addressed to Luis Ricardo Hern´ andez; luisr.hernandez@udlap.mx Received 15 November 2018; Revised 19 February 2019; Accepted 20 March 2019; Published 11 April 2019 Academic Editor: Gail B. Mahady Copyright © 2019 Enrique Vergara Barrag´ an 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. Lopezia racemosa Cav. (Onagraceae) has been used in Mexican traditional medicine to alleviate stomachache, biliary colic, urine retention, stomach cancer, and skin, dental, buccal, and urinary infections. Te objective of this study was to determine the bioactivities of specifc parts of the plant to scientifcally confrm its traditional use. Aerial parts and fowers were macerated and subsequently extracted with hexane, chloroform, and methanol. Tis study was focused on the analysis of polar components, and thus the methanolic fractions were selected for further investigations. Tese fractions were evaluated for their antimicrobial activity using a panel of bacterial Gram-positive and -negative strains, as well as fungal strains, including flamentous fungi and yeasts. In addition, the cytotoxic activity of the extract was assessed by MTT using the human-derived monocytic THP-1 and the normal human fbroblast cell lines. Various fractions showed antimicrobial activity against various pathogens, although the most relevant were against Pseudomonas aeruginosa and Trichophyton mentagrophytes. No inhibition of yeasts was recorded. Only four fractions showed cytotoxic efects when the human-derived THP-1 and fbroblast cells were assessed. Te four favonoids isolated from the extract were luteolin, luteolin-6-C-hexoside, luteolin-8-C-hexoside, and hyperoside. Te biological activities presented in this study validate some traditional uses of the plant. 1. Introduction Te genus Lopezia (Onagraceae) consists of 45 species (www.theplantlist.org) restricted to a large extent to Mexico [1]. Te common names of Lopezia racemosa (synonym: L. mexicana) are “perilla”, “guayabilla”, “brad”, and “cancer weed” [2]. Te leaves of L. racemosa are used as an infusion to reduce toothache [3], to relieve stomach and throat pain, against stomach cancer, against infections in the urinary tract, to wash skin infections with pus [4], and against diarrhea [5]. Studies of genus Lopezia are very scarce and only a previ- ous study from our research group reported the antimicrobial activity of the chloroform and methanolic fractions from L. racemosa [6]. In that study, antibacterial and antifungal activities against a panel of strains were reported. Also, the cytotoxic activities of the hexane, chloroform, and methanol extracts against THP-1 cells were reported with IC 50 of 31 g/mL, 29 g/mL, and 30 g/mL, respectively [6]. Another study reported the production of the anti- infammatory compound 6-O-palmitoyl-3-O--D-glucopy- ranosylcampesterol using a callus culture of the same plant [7]. Following our research program of studying Mexican plants used in traditional medicine, we investigated the methanol extract and its fractions from the aerial parts of L. racemosa to evaluate the antimicrobial, antifungal, and cytotoxic activities. Te phytochemistry of the frac- tions was also studied and the identifed compounds were favonoids. 2. Material and Methods 2.1. Chemicals. Te following reagents were used: hexane, chloroform, methanol, and acetone from RBM (Puebla, Mexico); dimethyl sulfoxide (DMSO), formamide (FA), Hindawi BioMed Research International Volume 2019, Article ID 3286489, 10 pages https://doi.org/10.1155/2019/3286489