FULL COMMUNICATION Antiquorum Sensing Activity of Seed Oils from Oleaginous Plants and Protective Effect During Challenge with Chromobacterium violaceum Macrina Pe ´rez-Lo ´pez, 1 Rodolfo Garcı ´a-Contreras, 2 Marcos Soto-Herna ´ndez, 1 Jose ´ Salud Rodrı ´guez-Zavala, 3 Mariano Martı ´nez-Va ´zquez, 4 Francisco Javier Prado-Galbarro, 5 and Israel Castillo-Jua ´rez 1 1 Department of Botany, Postgraduate College-Montecillo, State of Mexico, Mexico. 2 Department of Microbiology and Parasitology, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico. 3 Department of Biochemistry, National Institute of Cardiology, Mexico City, Mexico. 4 Natural Products Laboratory, Institute of Chemistry, National Autonomous University of Mexico, Mexico City, Mexico. 5 Healthcare Technology Evaluation Agency, Carlos III Healthcare Institute, Madrid, Spain. ABSTRACT Seed oils from oleaginous plants are rich in fatty acids (FAs) that play important roles in the health of the consumers. Recent studies indicate that FA also can play an important role in communication and regulation of virulence in bacteria. Nevertheless, evidence demonstrating protection against bacterial infections mediated by their quorum sensing inhibition (QSI) activity is scarce. In this study, sunflower, chia, and amaranth oils, were assayed for their QSI capacity by inhibiting violacein production and alkaline exoprotease activity of Chromobacterium violaceum. In vitro assays revealed that the oils exhibited QSI activities, whereas in vivo they delayed death of mice inoculated intraperitoneally with the bacterium. Gas chromatography coupled with mass spectrometry analysis of the oils indicated the presence of saturated FA (SAFA) and unsaturated FA as main components. Through a structure–activity relationship study of free FAs, bactericidal effect was identified mainly for polyunsaturated FAs, whereas QSI activity was restricted to SAFA of chains 12–18 carbon atoms in length. These data correlate with a possible interaction suggested by molecular docking analysis of lauric, myristic, and stearic acids with the CviR protein. Our study highlights the antiquorum sensing potential of SAFA, which may be future anti- virulence therapeutic agents for the treatment of bacterial infections. KEYWORDS:  antivirulence activity  quorum quenching  quorum sensing  saturated fatty acids  sepsis model INTRODUCTION E dible fats and oils are an essential part of the animal diet as they play an important role in nutrition. 1 Al- though popular conceptions claim that fat should be reduced in diets, certain fatty acids (FAs) as supplements have an important role in improving health. 2 In recent years, research on consumption of FA in the diet has become an important topic. Polyunsaturated fatty acid (PUFA) series, x3 and x6, have been of greatest interest for the scientific community. 3 Oleaginous plant seeds are an important source of FA and possess high nutritional value. 4 Indiscriminate use of antibiotics has produced an alarm- ing increase in the number of resistant pathogenic bacteria. 5 Hence, emergence of resistance has become a threat and has been declared a public health problem worldwide. 6 However, the development of new antibiotics has been insufficient to cope with the dramatic increase of resistance selection. 7 Therefore, new approaches to combat bacterial infections are required 8 ; one of these is to primarily inhibit virulence rather than growth, for example by attenuating bacterial cell–cell communication known as quorum sensing (QS). 9 QS systems (QSS) are used by many microorganisms to modulate several processes, including the expression of virulence factors and biofilm formation. 10–14 QS inhibition (QSI) has been proposed as an alternative strategy that aims to counteract bacterial resistance. 13,14 QSI, then, represents a promising therapeutic approach with lower risk of selection for development of resistance than treatments with traditional antimicrobials. 15 In this respect, the QSS dependence on N-acyl homoserine lactones are the main regulators of virulence factor expression and biofilm development in several Gram-negative pathogenic bacteria. 16 Hence, their inhibition represents a very important novel approach for the design of new therapies. 15,17 In this regard, some FA that have shown bactericidal efficacy, particularly those that are unsaturated and have medium-long chains exhibit the best activities. 18,19 In addition, it has recently been reported that certain food Manuscript received 8 June 2017. Revision accepted 5 October 2017. Address correspondence to: Israel Castillo-Jua´rez, PhD, CONACyT Research Fellow- Department of Botany, Postgraduate College-Montecillo, Km. 36.5 Mexico-Texcoco Highway, Montecillo, Texcoco, Mexico State, C.P. 56230, Mexico, E-mail: israel.castillo@ colpos.mx JOURNAL OF MEDICINAL FOOD J Med Food 00 (0) 2017, 1–8 # Mary Ann Liebert, Inc., and Korean Society of Food Science and Nutrition DOI: 10.1089/jmf.2017.0080 1