Recently, we identified several flavonoids as inhibitors of the nuclear enzyme poly(ADP-ribose) polymerase (PARP)-1 in vitro and in vivo. PARP-1 is recognized as coactivator of nuclear factor-kappaB and plays a role in the pathophysiology of diseases with low-grade systemic inflammation, such as chronic obstructive pulmonary disease (COPD) and type 2 diabetes (T2D). In this study, we assessed the antiinflammatory effects of flavonoids with varying PARP-1-inhibiting effects in whole blood from male patients with COPD or T2D and healthy men. A total of 10 COPD, 10 T2D patients, and 10 healthy volunteers matched for age and BMI were recruited. Blood from each participant was exposed to 1 mug/L lipopolysaccharide (LPS) over 16 h with or without preincubation with 10 mumol/L of flavone, fisetin, morin, or tricetin. Concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, -8, and -10 were measured in the supernatant. Preincubation with fisetin and tricetin strongly attenuated LPS-induced increases in concentrations of TNFalpha in blood from COPD patients [mean (+/- SEM): -41 +/- 4% (fisetin) and -31 +/- 4% (tricetin); P < 0.001] and IL-6 in blood from T2D patients [-31 +/- 5% (fisetin) and -29 +/- 6% (tricetin); P </= 0.001]. Moreover, LPS-induced changes in TNFalpha and IL-6 concentrations were positively correlated with the extent of reduction by fisetin and tricetin. The PARP-1-inhibiting flavonoids fisetin and tricetin were able to attenuate LPS-induced cytokine release from leukocytes of patients with chronic systemic inflammation, indicating a potential application as nutraceutical agents for these patient groups.
Weseler, A. R., Geraets, L., Moonen, H. J., Manders, R. J., van Loon, L. J., Pennings, H. J., Wouters, E. F., Bast, A., & Hageman, G. J. (2009). Poly (ADP-ribose) Polymerase-1-Inhibiting Flavonoids Attenuate Cytokine Release in Blood from Male Patients with Chronic Obstructive Pulmonary Disease or Type 2 Diabetes. Journal of Nutrition, 139(5), 952-957. https://doi.org/10.3945/jn.108.102756