Meloxicam affects the inflammatory responses of bovine mammary epithelial cells

Abstract

Nonsteroidal anti-inflammatory drugs are used as supportive therapy with antimicrobial treatments for mastitis in cows to alleviate pain of the inflamed mammary gland. They act mainly by inhibition of cyclooxygenases. Meloxicam (MEL) is a drug designed for cyclooxygenase-2 selectivity, which is upregulated upon inflammation, acting as a key enzyme for the conversion of arachidonic acid to prostaglandins. Although some studies in dairy cows showed positive results in recovery from mastitis when MEL was added to the treatments, direct effects of MEL on the immune system of mastitic cows are unknown. The aim of this study was to investigate effects of MEL on the immune response of bovine mammary epithelial cells (MEC) with or without simultaneous immune stimulation by pathogen-associated molecular patterns of common mastitis pathogens. Mammary epithelial cells from 4 cows were isolated and cultured. To evaluate dose effects of MEL, MEC were challenged with or without 0.2 µg/mL lipopolysaccharide (LPS; serotype O26:B6 from Escherichia coli) with addition of increasing concentrations of MEL (0, 0.25, 0.5, 1.0, 1.5, or 2.0 mg/mL). The addition of MEL prevented the increase of mRNA expression of key inflammatory factors in LPS-challenged MEC in a dose-dependent manner. To investigate the effects of MEL on pathogen-specific immune responses of MEC, treatments included challenges with LPS from E. coli and lipoteichoic acid from Staphylococcus aureus with or without 1.5 mg/mL MEL for 3, 6, and 24 h. Meloxicam prevented the increase of mRNA abundance of key inflammatory mediators in response to LPS and lipoteichoic acid, such as tumor necrosis factor, serum amyloid A, inducible nitric oxide synthase, and the chemokines IL-8 and CXC chemokine ligands 3 and 5. The prostaglandin E 2 synthesis in challenged and nonchallenged cells was reduced by MEL within 24 h. Furthermore, MEL reduced the viability and consequently the total RNA yield of the cells. However, mRNA abundance of apoptosis-related enzymes was not affected by any treatment. Meloxicam had clear dose-dependent effects on the immune response of MEC to pathogen-associated molecular patterns of common mastitis pathogens by preventing increased expression of important factors involved in inflammation. This nonsteroidal anti-inflammatory drug also has detrimental effects on cell viability. How these effects would influence the elimination of pathogens from an infected mammary gland during mastitis therapy with meloxicam needs to be further investigated.

Oral Meloxicam Administration in Sows at Farrowing and Its Effects on Piglet Immunity Transfer and Growth

“…Our data support the local role of oral meloxicam in the mammary gland, which likely decreases local inflammation, thus favoring both immunoglobulin recruitment from plasma and local production of IgA in plasma cells (1). Indeed, in vitro studies developed in cattle have shown the anti-inflammatory effect of meloxicam in mammary epithelial cells (25). Furthermore, mastitis in cows has been associated with reduced pre-weaning immunity, growth, and health of the offspring (26,27), so the anti-inflammatory effect elicited by meloxicam treatment is presumed to have the opposite effect.…”

Immunomodulatory Effects of the Cyclooxygenase Inhibitor Lornoxicam on Phenotype and Function of Camel Blood Leukocytes

“…The in vitro pro-apoptotic effect of lornoxicam on camel leukocytes at concentrations that can be easily reached in plasma after the administration of lornoxicam in vivo indicates a role for lornoxicaminduced cell death in the reduced leukocyte numbers in lornoxicam-injected camels. A similar detrimental effect on cell viability was reported in bovine mammary epithelial cells treated with meloxicam [31]. Cell apoptosis is mainly regulated by caspases, a family of cysteine proteases, including caspase-2, -8, -9, -10, -11, and -12.…”

Effects of Peptidoglycan, Lipoteichoic Acid and Lipopolysaccharide on Inflammation, Proliferation and Milk Fat Synthesis in Bovine Mammary Epithelial Cells

“…The construction of mastitis model of cows was frequently based on 1 μg/mL LPS stimulation for BMECs in vitro in many studies [ 33 , 34 , 35 , 36 , 37 ]. There were some studies which reported that a lower concentration of LPS, such as 0.1 [ 38 , 39 ], 0.2 [ 40 , 41 ], 0.5 [ 42 ] μg/mL and so on, could also induce inflammatory responses of BMECs. In the present study, 0.01 μg/mL LPS only significantly promoted the gene expression of IL-6 and IL-8 .…”