Inhibitory Effects Of Pterostilbene Research Articles

Triad3A-Dependent TLR4 Ubiquitination and Degradation Contributes to the Anti-Inflammatory Effects of Pterostilbene on Vascular Dementia.

Pterostilbene, a methylated stilbene derived from many plant foods, has significant anti-inflammatory activity. Meanwhile, vascular dementia (VaD) is the second most common subtype of dementia, in which inflammation is one of the major pathogenic contributors. However, the protective effect of pterostilbene on VaD is not well understood. In this work, we investigated the effect of pterostilbene on VaD and explored its underlying mechanisms using in vivo and in vitro models. Y-maze and Morris water maze tests showed pterostilbene-attenuated cognitive impairment in mice with bilateral common carotid artery occlusion (BCCAO). The hippocampal neuronal death and microglial activation in BCCAO mice were also reduced by pterostilbene treatment. Further, pterostilbene inhibited the expression of TLR4 and downstream inflammatory cytokines in these mice, with similar results observed in an oxygen-glucose deprivation and reperfusion (OGD/R) BV-2 cell model. In addition, its anti-inflammatory effect on OGD/R BV-2 cells was partially blocked by TLR4 overexpression. Moreover, Triad3A-TLR4 interactions were increased by pterostilbene following enhanced ubiquitination and degradation of TLR4, and the inhibitory effect of pterostilbene on inflammation was blocked by Triad3A knockdown in OGD/R-stimulated BV-2 cells. Together, these results reveal that pterostilbene could reduce vascular cognitive impairment and that Triad3A-mediated TLR4 degradation might be the key target.

Pterostilbene suppresses oral cancer cell invasion by inhibiting MMP-2 expression

Objective: Polyphenol compounds, present in a wide variety of natural plants, exhibit antioxidant and free radical scavenging ability and induce apoptosis in various cancer cells. However, the effect of pterostilbene on oral cancer cell metastasis has not been clarified.Research design and methods: The present study aimed to examine the anti-metastatic properties of pterostilbene in human oral squamous cell carcinoma (SCC)-9 cells.Results: In this study, pterostilbene treatment significantly inhibited migration/invasion capacities of SCC-9 cells in vitro. The results of zymography and western blotting revealed that the activities and protein levels of the MMP-2 and urokinase-type plasminogen activator (u-PA) was inhibited by pterostilbene. Western blot analysis also showed that pterostilbene inhibits the phosphorylation of Akt, extracellular signal-regulated kinase 1/2 and p38. Determinations of the mRNA levels, real-time polymerase chain reaction and promoter assays were conducted to evaluate the inhibitory effects of pterostilbene on MMP-2 and u-PA expression in SCC-9 cells. Such inhibitory effects were associated with the upregulation of tissue inhibitor of metalloproteinase-2, plasminogen activator inhibitor-1 and the downregulation of the transcription factors of NF-κB, SP-1 and CREB signaling pathways.Conclusions: Pterostilbene may have potential use as a chemopreventive agent against oral cancer metastasis.

Urokinase-type plasminogen activator expression and Rac1/WAVE-2/Arp2/3 pathway are blocked by pterostilbene to suppress cell migration and invasion in MDA-MB-231 cells

Breast cancer is the most common malignancy among females, and cancer invasion and metastasis are the leading causes of cancer death in breast cancer patients. Pterostilbene, a naturally occurring dimethylether analogue of resveratrol, has been demonstrated to possess anti-cancer effects. However, inhibitory effects of pterostilbene on cell migration and invasion and its underlying mechanisms are not fully understood. In this study, we investigated the anti-invasive mechanisms of pterostilbene in human breast cancer cell line MDA-MB-231 cells. Pterostilbene effectively inhibited serum-induced migration and invasion without affecting the viability of breast cancer cells. The mRNA expression and activity of urokinase-type plasminogen activator (uPA) were markedly reduced by pterostilbene treatment. Moreover, pterostilbene attenuated nuclear factor κB (NF-κB) transcriptional activity and DNA binding of NF-κB on uPA promoter. In addition, pterostilbene significantly impaired the activity of Rac1 and the expression of WASP-family verprolin-homologous protein-2 (WAVE-2) and actin-related protein 2/3 (Arp2/3). Overall, these results suggest that pterostilbene caused considerable suppression of cell migration and invasion through blocking NF-κB-mediated uPA expression and Rac1/WAVE/Arp2/3 pathway.

The Inhibitory Effect of Pterostilbene on Inflammatory Responses during the Interaction of 3T3-L1 Adipocytes and RAW 264.7 Macrophages

Chronic inflammation is characterized by the upregulation of proinflammatory cytokines in obese adipose tissue. Accumulations of adipose tissue macrophages enhance a chronic inflammatory state in adipose tissues. Many studies have indicated that the adipocyte-related inflammatory response in obesity is characterized by an enhanced infiltration of macrophages. The aim of this work was to study the inhibitory effects of garcinol and pterostilbene on the change in inflammatory response due to the interaction between 3T3-L1 adipocytes and RAW 264.7 macrophages. In the TNF-α-induced 3T3-L1 adipocyte model, garcinol and pterostilbene significantly decreased the mRNA expression of COX-2, iNOS, IL-6, and IL-1β and IL-6 secretion by suppressing phosphorylation of p-IκBα and p-p65. In a coculture model of 3T3-L1 adipocytes and RAW 264.7 macrophages, pterostilbene suppressed IL-6 and TNF-α secretion and proinflammatory mRNA expression and also reduced the migration of macrophages toward adipocytes. In the RAW 264.7 macrophage-derived conditioned medium (RAW-CM)-induced 3T3-L1 adipocyte and 3T3-CM-induced RAW 264.7 macrophage models, pterostilbene significantly decreased IL-6 and TNF-α secretion and proinflammatory mRNA expression (COX-2, iNOS, IL-6, TNF-α, PAI-1, CRP, MCP-1, resistin, and leptin). Our findings suggest that garcinol and pterostilbene may provide novel and useful applications to reduce the chronic inflammatory properties of adipocytes. We also found that pterostilbene inhibits proinflammatory responses during the interaction between 3T3-L1 adipocytes and RAW 264.7 macrophages.