Evaluation of the inflammatory response in peripheral blood mononuclear cells of young adults with different body compositions and physical aptitudes: role of capsaicin and adrenergic receptors

Insufficient levels of physical activity and poor eating habits are related to excessive accumulation of visceral adipose tissue, changes in sympathetic nervous system responses, and low-grade chronic inflammation. The adoption of regular physical exercise combined with the help of food supplements can optimize the reduction of visceral fat stores, regulate the expression of β2 adrenergic receptors (AR-β2), as well as increase cardiorespiratory capacity, which together contribute for the reduction of circulating pro-inflammatory cytokine concentrations. In the present study, we first analyzed the impact of different status of body composition (eutrophic and overweight/obese) and levels of cardiorespiratory fitness (sedentary and athletes) on the systemic metabolic and inflammatory profile. ex vivo (peripheral blood) and in vitro (peripheral blood mononuclear cells (PBMC)). Additionally, the potential regulatory effect of capsiate and the role of the AR-β2 pathway in PBMC of individuals with different body compositions and levels of physical fitness were evaluated. To answer these questions, twenty-three healthy young people classified as eutrophic, overweight/obese, sedentary and athletes were recruited. Body composition assessments and blood collection at rest/fasting were performed for biochemical analysis and ex vivo and in vitro assays. In the first article, PBMCs from overweight/obese individuals produced higher absolute concentrations of tumor necrosis factor – alpha (TNF-α) in parallel with lower relative concentrations of TNF-α, interleukin (IL) – 10 and macrophage inflammatory protein – 1 alpha (MIP-1α) compared to eutrophic individuals. Additionally, sedentary individuals had higher concentrations of circulating IL-6, higher relative values of TNF-α and higher rates of basal oxygen consumption in PBMC compared to athletes. In the second article, capsiate stimulation as well as selective inhibition of AR-β2 were not able to promote modulations in cytokine concentrations in PBMCs. In conclusion, body composition and physical fitness impact the profile and inflammatory response of PBMCs, however, capsiate stimulation and AR-β2 inhibition did not promote the modulation of the inflammatory response. (AU)