Palm tocotrienols decrease levels of pro-angiogenic markers in human umbilical vein endothelial cells (HUVEC) and murine mammary cancer cells

• Main Authors: Kanga Rani, Selvaduray,, Kalanithi, Nesaretnam,, Ammu K., Radhakrishnan,, Methil Kannan, Kutty,
• Format: Article
• Language: English
• Published: Springer 2015
• Subjects: Angiogenesis; Palm Tocotrienol; IL-6; IL-8; VEGF; VEGF Receptors
• Online Access: http://ddms.usim.edu.my/handle/123456789/8338

Anti-angiogenic therapy is widely being used to halt tumour angiogenesis. In this study, the anti-angiogenic activity of palm tocotrienol-rich fraction (TRF) and its individual components (gamma- and delta-tocotrienol) were first investigated in vitro in human umbilical vein endothelial cells (HUVEC) and 4T1 mouse mammary cancer cells. Results showed reduced levels of Interkeukin (IL)-8 and IL-6, two pro-angiogenic cytokines in HUVEC treated with palm tocotrienols compared with alpha-tocopherol (alpha-T) and control cells (P < 0.05). The production of IL-8 and IL-6 was lowest in delta-tocotrienol (delta-T3)-treated cells followed by gamma-tocotrienol (gamma-T3) and TRF. There was significant (P < 0.05) reduction in IL-8 and vascular endothelial growth factor (VEGF) production in 4T1 cells treated with TRF or delta-T3. There was decreased expression of VEGF and its receptors; VEGF-R1 (fms-like tyrosine kinase, Flt-1) and VEGF-R2 (Kinase-insert-domain-containing receptor, KDR/Flk-2) in tumour tissues excised from mice supplemented with TRF were observed. There was also decreased expression of VEGF-R2 in lung tissues of mice supplemented with TRF. These observations correlate with the smaller tumour size recorded in the tocotrienol-treated mice. This study confirms previous observations that palm tocotrienols exhibit anti-angiogenic properties that may inhibit tumour progression.