Resistance Exercise and Polyphenol Supplementation elicits Unique Recruitment of Monocyte Subsets in Untrained Men

Abstract

PURPOSE: To examine the monocyte subset response to resistance exercise and supplementation with an aqueous proprietary polyphenol blend (PPB) sourced from Camellia sinensis. METHODS: Untrained men (n=38, 22.1 ± 3.1 yrs; 174.0 ± 7.9 cm; 77.8 ± 14.5 kg) were randomized to: PPB (n=13), placebo (PL; n=15) or control (CON; n=10). PPB and PL supplemented for 28 days prior to an acute bout of resistance exercise, consisting of 10 repetitions at 70% of 1-RM for the squat (6 sets), leg press (4 sets) and leg extension (4 sets). Blood was drawn pre (PR), immediately (IP), 1 (1H), 5 (5H), 24 (24H) and 48 (48H) hours post exercise (PPB/PL), or rest (CON). Biopsies were obtained from the vastus lateralis at PR, 1H, 5H and 48H. Plasma and intramuscular monocyte chemoattractant protein-1 (MCP-1) was assessed by multiplex assay. Relative percent of classical (CLAS; CD14++/CD16-), intermediate (INT; CD14++/CD16+) and nonclassical (NC; CD14+/CD16+) monocytes were assessed via flow cytometry. Repeated measures ANOVA were applied, and non-normally distributed data were LN transformed. RESULTS: A group x time interaction was observed for circulating MCP-1 (p = 0.005), which was greater at 5H in PPB (502.0 ± 154.2 pg[BULLET OPERATOR]ml-1; p = 0.001) and PL (416.8 ± 109.9 pg[BULLET OPERATOR]ml-1; p = 0.012) than CON (307.3 ± 142.6 pg[BULLET OPERATOR]ml-1). A time effect was observed for intramuscular MCP-1 content (p < 0.001), with elevations observed (PR: 9.6 ± 5.0 pg[BULLET OPERATOR]mg-1; p < 0.001) at 1H (374.2 ± 388.8 pg[BULLET OPERATOR]ml-1), 5H (595.7 ± 528.6 pg[BULLET OPERATOR]ml-1) and 48H (217.0 ± 189.1 pg[BULLET OPERATOR]ml-1). Interactions were observed for CLAS, INT and NC (p < 0.001) populations. At IP, CLAS was reduced in PPB (86.2 ± 7.6%; p = 0.008) and PL (85.9 ± 5.1%; p = 0.003) versus CON (93.8 ± 4.3%). At 1H, PPB (96.3 ± 2.0%; p = 0.002) and PL (95.3 ± 4.0%; p = 0.006) was greater than CON (90.8 ± 4.3%). INT were greater at IP in PPB (4.9 ± 2.3%; p = 0.034) and PL (6.0 ± 2.0; p = 0.001) than CON (2.9 ± 1.8%) and reduced at 1H in PPB (1.6 ± 1.0%; p = 0.003) and PL (2.0 ± 1.2%; p = 0.008) versus CON (3.4 ± 1.6%). PPB was greater than CON at 24H (6.7 ± 2.9%; 4.0 ± 0.9%; p = 0.016) and 48H (7.9 ± 3.4%; 4.1 ± 1.6%; p = 0.007). NC was greater at IP in PPB (8.9 ± 6.9%; p = 0.020) and PL (8.1 ± 4.0%; p = 0.028) than CON (3.4 ± 3.2%). CONCLUSIONS: Exercise resulted in increased MCP-1 and the mobilization of specific monocyte subsets. Supplementation with PPB may augment the monocyte response. Funded by Kemin Foods, L.C.