gamma-Tocotrienol

γ-Tocotrienol is an active form of vitamin E. γ-tocotrienol reverses the multidrug resistance (MDR) of breast cancer cells through the signaling pathway of NF-κB and P-gp. γ-Tocotrienol is also a novel radioprotector agent, can mitigate bone marrow radiation damage during targeted radionuclide treatment.

γ-Tocotrienol (25 μM; 24 h) effectively inhibits the expression levels of mdr1 mRNA and P-gp protein, (25 μM and 50 μM; 24 h) suppresses mdr1 promoter activity and the efflux activity of P-gp as well^[2].
γ-Tocotrienol (25 μM and 50 μM; 24 h) reduces the activation of NF-κB signaling pathway and the transcriptional activity of NF-κB^[2].
γ-tocotrienol (50 μM; 48 h) effectively inhibits the process of nuclear translocation of p65 which was induced by TNFα^[2].

γ-Tocotrienol’s liposomal formulation, GT3-Nano (20 mol% γ-Tocotrienol), (10 mg/kg, 6 mol%; i.v.; single dose, observed for 100 d) is highly effective in mitigating the marrow-suppressive effects of sublethal and lethal TBI in mice^[3].
GT3-Nano (50 mg/kg; i.v.; ) can facilitate rapid recovery of hematopoietic components in mice treated with the endoradiotherapeutic agent ¹⁵³Sm-EDTMP^[3].

References:

[1]. M A Newaz, et al. Nitric Oxide Synthase Activity in Blood Vessels of Spontaneously Hypertensive Rats: Antioxidant Protection by Gamma-Tocotrienol. J Physiol Pharmacol. 2003 Sep;54(3):319-27. 

[2]. Ding Y, et al. γ-Tocotrienol reverses multidrug resistance of breast cancer cells through the regulation of the γ-Tocotrienol-NF-κB-P-gp axis. J Steroid Biochem Mol Biol. 2021 May;209:105835.  

[3]. Lee SG, et al. γ-Tocotrienol-Loaded Liposomes for Radioprotection from Hematopoietic Side Effects Caused by Radiotherapeutic Drugs. J Nucl Med. 2021 Apr;62(4):584-590.