Research Article Lipid-Rich Extract from Mexican Avocado Seed (Persea americana var. drymifolia) Reduces Staphylococcus aureus Internalization and Regulates Innate Immune Response in Bovine Mammary Epithelial Cells Marisol Báez-Magaña, 1 Alejandra Ochoa-Zarzosa , 1 Nayeli Alva-Murillo , 2 Rafael Salgado-Garciglia , 3 and Joel Edmundo López-Meza 1 1 Centro Multidisciplinario de Estudios en Biotecnología-FMVZ, Universidad Michoacana de San Nicolás de Hidalgo, Km 9.5 Carretera Morelia-Zinapécuaro, Posta Veterinaria C.P., 58893 Morelia, Michoacán, Mexico 2 Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, Mexico 3 Instituto de Investigaciones Químico Biológicas, UMSNH. Ciudad Universitaria, Morelia, Michoacán, Mexico Correspondence should be addressed to Joel Edmundo López-Meza; elmeza@umich.mx Received 20 May 2019; Accepted 23 August 2019; Published 12 September 2019 Guest Editor: Yanyan Qu Copyright © 2019 Marisol Báez-Magaña et al. This 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. Bovine mammary epithelial cells (bMECs) are capable of initiating an innate immune response (IIR) to invading bacteria. Staphylococcus aureus is not classically an intracellular pathogen, although it has been shown to be internalized into bMECs. S. aureus internalizes into nonprofessional phagocytes, which allows the evasion of the IIR and turns antimicrobial therapy unsuccessful. An alternative treatment to control this pathogen is the modulation of the innate immune response of the host. The Mexican avocado (Persea americana var. drymifolia) is a source of molecules with anti-inflammatory and immunomodulatory properties. Hence, we analyze the effect of a lipid-rich extract from avocado seed (LEAS) on S. aureus internalization into bMECs and their innate immunity response. The effects of LEAS (1-500 ng/ml) on the S. aureus growth and bMEC viability were assessed by turbidimetry and MTT assays, respectively. LEAS did not show neither antimicrobial nor cytotoxic effects. S. aureus internalization into bMECs was analyzed by gentamicin protection assays. Interestingly, LEAS (1- 200 ng/ml) decreased bacterial internalization (60-80%) into bMECs. This effect correlated with NO production and the induction of the gene expression of IL-10, while the expression of the proinflammatory cytokine TNF-α was reduced. These effects could be related to the inhibition of MAPK p38 (∼60%) activation by LEAS. In conclusion, our results showed that LEAS inhibits the S. aureus internalization into bMECs and modulates the IIR, which indicates that avocado is a source of metabolites for control of mastitis pathogens. 1. Introduction The innate immune response (IIR) is the first line of defense of organisms, which has a relevant role in the protection against pathogens. The participation of professional phago- cytic cells (c.a. macrophages, dendritic cells, and circulating leukocytes) in the IIR is fundamental; however, nonprofes- sional phagocytic cells (c.a. epithelium, endothelium, osteo- blast, and fibroblast cells) also have a relevant role [1]. In this sense, bovine mammary epithelial cells (bMECs) play an important role in the IIR of the mammary gland acting as a physical barrier and as initial sensors of danger with the capacity to mount a defense response [2]. The IIR regula- tion by immunomodulatory molecules such as fatty acids and vitamins has been widely demonstrated and involves epige- netics changes that can be stably maintained or adapted to Hindawi Journal of Immunology Research Volume 2019, Article ID 7083491, 10 pages https://doi.org/10.1155/2019/7083491