I have been taking some vitamin K1 & k2 combo for many years. My main reason was first to prevent calicification of my arteries and heart valves. I also take some Vinpocetine which has a similiar effect and may even remove some unwanted calcium deposits.
jackDhttp://www.lef.org/Vitamins-Supplements ... itamin%20k
J Neurosci. 2003 Jul 2;23(13):5816-26.Novel role of vitamin k in preventing oxidative injury to developing oligodendrocytes and neurons.
Li J, Lin JC, Wang H, Peterson JW, Furie BC, Furie B, Booth SL, Volpe JJ, Rosenberg PA.
Department of Neurology, Division of Neuroscience, Children's Hospital, Boston, MA 02115, USA.
Oxidative stress is believed to be the cause of cell death in multiple disorders of the brain, including perinatal hypoxia/ischemia. Glutamate, cystine deprivation, homocysteic acid, and the glutathione synthesis inhibitor buthionine sulfoximine all cause oxidative injury to immature neurons and oligodendrocytes by depleting intracellular glutathione.Although vitamin K is not a classical antioxidant, we report here the novel finding that vitamin K1 and K2 (menaquinone-4) potently inhibit glutathione depletion-mediated oxidative cell death in
primary cultures of oligodendrocyte precursors and immature fetal cortical neurons with EC50 values of 30 nm and 2 nm, respectively. The mechanism by which vitamin K blocks oxidative injury is independent of its only known biological function as a cofactor for gamma-glutamylcarboxylase, an enzyme responsible for posttranslational modification of specific proteins. Neither oligodendrocytes nor neurons possess significant vitamin K-dependent carboxylase or epoxidase activity. Furthermore, the vitamin K antagonists warfarin and dicoumarol and the direct carboxylase inhibitor 2-chloro-vitamin K1 have no effect on the protective function of vitamin K against oxidative injury.
Vitamin K does not prevent the depletion of intracellular glutathione caused by cystine deprivation but completely blocks free radical accumulation and cell death.
The protective and potent efficacy of this naturally occurring vitamin, with no established clinical side effects, suggests a potential therapeutic application in preventing oxidative damage to undifferentiated oligodendrocytes in perinatal hypoxic/ischemic brain injury.
PMID: 12843286 [PubMed - indexed for MEDLINE
J Neurosci Res. 2009 Jul;87(9):1997-2005.
Vitamin K prevents oxidative cell death by inhibiting activation of 12-lipoxygenase in developing oligodendrocytes.
Li J, Wang H, Rosenberg PA.
The F.M. Kirby Neurobiology Center, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA.
Oxidative mechanisms of injury are important in many neurological disorders. Developing oligodendrocytes (pre-OLs) are particularly sensitive to oxidative stress-mediated injury. We previously demonstrated a novel function of phylloquinone (vitamin K(1)) and menaquinone 4 (MK-4; a major form of vitamin K2) in protecting pre-OLs and immature neurons against glutathione depletion-induced oxidative damage (Li et al. [ 2003] J. Neurosci. 23:5816-5826).
Here we report that vitamin K at nanomolar concentrations prevents arachidonic acid-induced oxidative injury to pre-OLs through blocking the activation of 12-lipoxygenase (12-LOX). Arachidonic acid metabolism is a potential source for reactive oxygen species (ROS) generation during ischemia and reperfusion. Exposure of pre-OLs to arachidonic acid resulted in oxidative cell death in a concentration-dependent manner. Administration of vitamin K (K(1) and MK-4) completely prevented the toxicity.
Consistent with our previous findings, inhibitors of 12-LOX abolished ROS production and cell death, indicating that activation of 12-LOX is a key event in arachidonic acid-induced pre-OL death. Vitamin K(1) and MK-4 significantly blocked 12-LOX activation and prevented ROS accumulation in pre-OLs challenged with arachidonic acid. However, vitamin K itself did not directly inhibit 12-LOX enzymatic activity when assayed with purified 12-LOX in vitro.
These results suggest that vitamin K, or likely its metabolites, acts upstream of activation of 12-LOX in pre-OLs. In summary, our data indicate that vitamin K prevents oxidative cell death by blocking activation of 12-LOX and ROS generation.
(c) 2009 Wiley-Liss, Inc.
PMID: 19235890 [PubMed - indexed for MEDLINE] PMCID: PMC2911960