Pinoresinol ((+)-Pinoresinol) has antiinflammatory, hepatoprotective, and fungicidal activities, it can protect pial microcirculation from I-reperfusion injury, to increase nitric oxide release and to reduce oxidative stress preserving pial blood flow distribution; it may exert pharmacologically interesting effects via modulation of the insulin-like signalling pathway in C.elegans. Pinoresinol causes an upregulation of the CDK inhibitor p21(WAF1/Cip1) both at mRNA and protein levels, inhibits NF-kappaB and activating protein 1 (AP-1).

Six lignan standards [secoisolariciresinol diglucoside (SDG), secoisolariciresinol (SECO), Pinoresinol (PINO), lariciresinol, matairesinol (MAT), and hydroxymatairesinol] and their colonic metabolites [enterolactone (ENL) and enterodiol] were studied. First, differentiated cells were exposed to SDG, SECO, PINO, or ENL at increasing concentrations for 4 h, and their cellular contents (before and after deconjugation) were determined by HPLC. Second, in IL-1β-stimulated confluent and/or differentiated cells, lignan effects were tested on different soluble proinflammatory mediators quantified by enzyme immunoassays and on the NF-κB activation pathway by using cells transiently transfected. SECO, PINO, and ENL, but not SDG, were taken up and partly conjugated by cells, which is a saturable conjugation process. PINO was the most efficiently conjugated (75% of total in cells). In inflamed cells, PINO significantly reduced IL-6 by 65% and 30% in confluent and differentiated cells, respectively, and cyclooxygenase (COX)-2-derived prostaglandin E(2) by 62% in confluent cells. In contrast, MAT increased significantly COX-2-derived prostaglandin E(2) in confluent cells. Moreover, PINO dose-dependently decreased IL-6 and macrophage chemoattractant protein-1 secretions and NF-κB activity[1]