Effects of Arachidonic Acid Supplementation on Acute Anabolic Signaling and Chronic Functional Performance and Body Composition Adaptations

RESEARCH ARTICLE Effects of Arachidonic Acid Supplementation on Acute Anabolic Signaling and Chronic Functional Performance and Body Composition Adaptations a11111 Eduardo O. De Souza1*, Ryan P. Lowery1, Jacob M. Wilson1, Matthew H. Sharp1, Christopher Brooks Mobley2, Carlton D. Fox2, Hector L. Lopez3, Kevin A. Shields1, Jacob T. Rauch1, James C. Healy2, Richard M. Thompson2, Jacob A. Ormes1, Jordan M. Joy1, Michael D. Roberts2 1 Department of Health Sciences and Human Performance, The University of Tampa, Tampa, FL, United States of America, 2 Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States of America, 3 The Center for Applied Health Sciences, 4302 Allen Road, STE 120, Stow, OH, 44224, United States of America * OPEN ACCESS Citation: De Souza EO, Lowery RP, Wilson JM, Sharp MH, Mobley CB, Fox CD, et al. (2016) Effects of Arachidonic Acid Supplementation on Acute Anabolic Signaling and Chronic Functional Performance and Body Composition Adaptations. PLoS ONE 11(5): e0155153. doi:10.1371/journal. pone.0155153 Editor: Andrew Philp, University of Birmingham, UNITED KINGDOM Received: July 7, 2015 Abstract Background The primary purpose of this investigation was to examine the effects of arachidonic acid (ARA) supplementation on functional performance and body composition in trained males. In addition, we performed a secondary study looking at molecular responses of ARA supplementation following an acute exercise bout in rodents. Accepted: April 25, 2016 Published: May 16, 2016 Copyright: © 2016 De Souza et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper. Funding: This study was funded in part by Molecular Nutrition TM. The funder provided support by paying the reagents for the muscle samples analysis. Molecular Nutrition TM did not have any additional roles in the study conception, data collection and analysis, input on the decision to publish or mannuscript preparation. All the other costs other than aforementioned were supported by Molecular and Applied Sciences Laboratory (Auburn University) Methods Thirty strength-trained males (age: 20.4 ± 2.1 yrs) were randomly divided into two groups: ARA or placebo (i.e. CTL). Then, both groups underwent an 8-week, 3-day per week, nonperiodized training protocol. Quadriceps muscle thickness, whole-body composition scan (DEXA), muscle strength, and power were assessed at baseline and post-test. In the rodent model, male Wistar rats (~250 g, ~8 weeks old) were pre-fed with either ARA or water (CTL) for 8 days and were fed the final dose of ARA prior to being acutely strength trained via electrical stimulation on unilateral plantar flexions. A mixed muscle sample was removed from the exercised and non-exercised leg 3 hours post-exercise. Results Lean body mass (2.9%, p<0.0005), upper-body strength (8.7%, p<0.0001), and peak power (12.7%, p<0.0001) increased only in the ARA group. For the animal trial, GSK-β (Ser9) phosphorylation (p<0.001) independent of exercise and AMPK phosphorylation after exercise (p-AMPK less in ARA, p = 0.041) were different in ARA-fed versus CTL rats. PLOS ONE | DOI:10.1371/journal.pone.0155153 May 16, 2016 1 / 20 Arachidonic Acid and Resistance Training and Human Performance Laboratory (University of Tampa). Competing Interests: This study was partially funded by Molecular Nutrition TM. Patent details to declare: product: 'X-Factor Advanced', patent number: #6.841.573. There are no further patents, products in development, or marketed products to declare. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors. Conclusions Our findings suggest that ARA supplementation can positively augment strength-training induced adaptations in resistance-trained males. However, chronic studies at the molecular level are required to further elucidate how ARA combined with strength training affect muscle adaptation. Introduction Fatty acids supplementation has received a high degree of popularity for increasing health benefits. For instance, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation have been utilized to reduce skeletal muscle inflammation and protein breakdown, as well as neural and cardiometabolic health [1, 2]. Specifically, one such fatty acid that has garnered a progressive amount of scrutiny over recent years is arachidonic acid (ARA). ARA is a long-chain polyunsaturated fatty acid (20:4n-6) that exists in relatively low amounts in the typical American diet [3]. In this regard, ARA is primarily consumed through meat and fish products. In the human body, ARA resides in the phospholipid bi-layer of cell membranes at concentrations contingent upon dietary intake [4]. While the literature illustrates the responsiveness of cell membrane composition to dietary intakes, phospholipids also appear to be dependent upon activity level suggesting increased ARA turnover or demand. For example, Andersson et al. (2000) noted a lower n-6:n-3 ratio and lower total n-6 fatty acids in phospholipids of exercising individuals [5, 6]. Likewise, Helge et al. (2001) similarly demonstrated that a lower n-6:n-3 ratio exists in strength-trained individuals [7]. Furthermore, ARA drives the inflammatory response to strength training [7]. To this end, this inflammatory response appears to be mediated by ARA liberated from plasma membranes via phospholipase A2 (PLA2). The free ARA follows its metabolic fate to generate bioactive lipid mediators known as eicosanoids by one of three biochemical pathways involving lipoxygenases (LOX), P450 epoxygenases or cyclooxygenases (COX) [8]. COX enzyme plays an important role for converting ARA to form postranoids such as Prostaglandins [9–11]. In addition, Prostaglandin E2 (PGE2) and Prostaglandin F2-α (PGF2-α) appear to be associated with protein degradation and synthesis in skeletal muscle, respectively [12]. Moreover, PGF2-α has been shown to elicit essential pathways responsible for myogenic proliferation, differentiation, and fusion in vitro [13, 14]. For instance, previous research demonstrated that in vitro ARA supplementation stimulates prostaglandins release and skeletal muscle hypertrophy via a COX-2 dependent pathway [9]. Moreover, animal model studies also demonstrated that COXinhibitors consumption attenuates muscle hypertrophy and regrowth from muscle atrophy [15]. However, in humans, after COX-inhibitors consumption, ARA-derived prostaglandins have demonstrated conflicting results concerning their role in acute post-strength training muscle protein synthesis and training-induced adaptations [16, 17]. For instance, previous research examined (...truncated)