Pan and co-workers at the National Kaohsiung Marine University, Taiwan, investigated the inhibitory effects of pterostilbene on the induction of nitric oxide synthase and cyclooxygenase-2 in macrophages activated with lipopolysaccharides. They found that the phytochemical significantly blocked the protein and mRNA expression of both enzymes. Treatment with pterostilbene reduced nuclear translocation of the nuclear factor-kappaB subunit and the dependent transcriptional activity of NFkappaB. The study concluded that pterostilbene may be a candidate for an effective anti-inflammatory agent.
A study conducted by Numico Research, The Netherlands, explored the anti-inflammatory effects of a plant extract containing pterostilbene in vitro and in healthy human volunteers . The team of researchers led by Hougee found that pterostilbene, resveratrol and plant extract inhibited prostaglandin E2 production from lipopolysaccharides-stimulated human blood cells. In healthy human volunteers, the plant extract did not decrease prostaglandin E2 production, because pterostilbene levels in serum were below the active concentrations observed in vitro.
Paul and co-workers at the State University of New Jersey investigated the anti-inflammatory effects of pterostilbene in colon cancer cells . Chronic inflammation is implicated in the pathology of colon cancer and anti-inflammatory compounds may be useful as chemopreventive agents. They found that pterostilbene reduced the expression of inflammation-related genes such as inducible nitric oxide synthase and cyclooxygenase-2.
 Pterostilbene suppressed lipopolysaccharide-induced up-expression of iNOS and COX-2 in murine macrophages. J Agric Food Chem. 2008 Aug 27;56(16):7502-9.
 Selective COX-2 inhibition by a Pterocarpus marsupium extract characterized by pterostilbene, and its activity in healthy human volunteers. Planta Med. 2005 May;71(5):387-92.
Anti-inflammatory action of pterostilbene is mediated through the p38 mitogen-activated protein kinase pathway in colon cancer cells. Cancer Prev Res (Phila). 2009 Jul;2(7):650-7.