β-Hydroxy-β-methylbutyrate (HMB)-free acid attenuates circulating TNF-α and TNFR1 expression postresistance exercise

Abstract

The purpose of this study was to examine the effect of β-hydroxy-β-methylbutyrate-free acid (HMB-FA) and cold-water immersion (CWI) on circulating concentrations of TNF-α and monocyte TNF-α receptor 1 (TNFR1) expression. Forty resistance-trained men (22.3 ± 2.4 yr) were randomized into four groups [placebo (PL), HMB-FA, CWI, and HMB-FA-CWI] and performed an acute, intense exercise protocol (four sets of up to 10 repetitions of the squat, dead lift, and split squat). Participants also performed four sets of up to 10 repetitions of the squat at 24 and 48 h following the initial exercise bout. Blood was sampled before exercise (PRE), immediately postexercise (IP), and 30 min, 24 h, and 48 h postexercise (30P, 24P, and 48P, respectively). Circulating TNF-α was assayed, and TNFR1 expression on CD14+ monocytes was measured by flow cytometry. The exercise protocol significantly elevated TNF-α in only PL (P = 0.006) and CWI (P = 0.045) IP. Mean percent changes show that TNF-α significantly increased from PRE to IP for only PL and CWI groups (P < 0.05), whereas the percent change of TNF-α for HMB-FA and HMB-FA-CWI was not significant. TNFR1 expression was elevated in PL (P = 0.023) and CWI (P = 0.02) at 30P compared with PRE, whereas both HMB-FA-treated groups did not increase significantly. In conclusion, HMB-FA attenuated circulating TNF-α IP and TNFR1 expression during recovery compared with PL and CWI. HMB-FA supplementation may attenuate the initial immune response to intense exercise, which may reduce recovery time following intense exercise.

Effects of &beta;-Hydroxy-&beta;-Methylbutyrate Supplementation on IL-4, IL-10 and TGF-&beta;1 during Resistance Exercise in Athletes

“…HMB supplementation increased circulating IL-4 by 19.75% immediately after heavy RE in resistance-trained men, which may be attributed to anti-inflammatory effect of HMB that supported by previous studies [6,24,25]. Consistent with our findings, previous study has shown that HMB exerts anti-inflammatory effect by attenuating elevations in circulating TNF-α immediately after acute bout of heavy RE and as well as reducing TNFR1 expression on human monocytes at 30 min post RE [6].…”

“…Tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1 and C reactive protein (CRP) are considered as low grade systemic inflammatory cytokines [4]. Studies examining the acute effect of RE on inflammatory markers revealed significant elevations [5,6] and no changes [2,7] in inflammatory cytokines. The inflammatory responses to a single bout of RE may be due to RE-induced muscle damage [8].…”

“…Recently, it was demonstrated TGF-β1 increased immediately after acute RE at low intensity (50% of 1 RM; 2x18 rps) in Coronary Artery Disease patients [15]. In addition to the effect of exercise on the immune system, previous studies have shown that diet and nutritional supplements can reinforce the immune system in athletes [6,[16][17][18].…”

“…To date, three studies only have been evaluated the effect of HMB on immune function during RE in humans [6,17,18]. Recently, it was proposed that HMB may exerts immunoregulatory effects including increased the anti-inflammatory cytokine IL-10 and decreasing pro-inflammatory cytokine IFN-γ and IL-1β after resistance training [17].…”

“…Recently, it was proposed that HMB may exerts immunoregulatory effects including increased the anti-inflammatory cytokine IL-10 and decreasing pro-inflammatory cytokine IFN-γ and IL-1β after resistance training [17]. In addition, it was reported that HMB could reduced TNF-α and monocyte TNF-α receptor 1 expression after strenuous RE [6]. In a vitro study demonstrated decrease in inflammatory cytokine IFN-γ in T-lymphocytes was incubated with varying concentrations of HMB [20].…”