Aim: 

Rottlerin is a polyphenolic compound purified from the tree Mallotus Philippinensis that has been used for centuries as a remedy for typeworm and in recent times, as an inhibitor of PKC. We recently found that Rottlerin also inhibits NFkB and cell proliferation in MCF-7 breast cancer cells. In this study, we examined the effect and action's mechanism of Rottlerin on angiogenesis in vitro.

Methods: 

Rottlerin (20 mM) was tested for its ability to inhibit the proliferation of primary endothelial cells (HMVEC) in the presence and absence of TNF alpha. Cell culture was established successfully at passages 3 and 4 at 80% confluence. Western blot analysis was performed in cell lysates to measure cyclin D1 and PARP. Cells cultured on cover slips were tested for NFkB (p50 subunit) expression and localization by immunocytochemical analysis.

Results: 

Rottlerin effectively inhibited endothelial cell proliferation (Thymidine incorporation) in a dose-dependent manner. At a concentration of 20

mM, Rottlerin significantly inhibited HMVEC proliferation, and also showed a significant reduction of TNF alpha-induced NFkB nuclear migration. Consistently, Rottlerin lowered the protein levels of NFkB target gene cyclin D1, thus causing cell cycle arrest and enhanced TNF alpha-triggered apoptosis, documented by the increase in PARP cleaved products, likely downregulating antiapoptotic proteins under the transcriptional control of NFkB. Furthermore, a decreases in VEGF protein levels were determined after Rottlerin treatment.

Conclusion: 

From these results, we suggest that Rottlerin may prove useful in the development of therapeutic agents against angiogenesis and iperproliferative diseases.