Vitamin K2 as MK-7 Shows Anti-Cancer Promise
Vitamin K2 has been demonstrated to exhibit an antiproliferative action towards a variety of cancer cells including lung cancer, ovarian cancer and acute myeloid leukemia cells. The antitumor effects of vitamin K2 have been most extensively studied in hepatocellular cancer with the use of menaquinone-4 (MK-4), but a recently published paper by Shi et al showed that menaquinone-7 (MK-7) exhibits also strong anticancer function.
In this study, the researchers designed a vitamin K2 (MK-7) nanoemulsion system modified with sialic acid–cholesterol conjugate (SA-CH) in order to enhance the antitumor effect.
Various parameters were evaluated, including particle size, morphology, stability, in vitro hemolysis, biodistribution, and in vivo and in vitro antitumor efficacy, to evaluate the efficacy of the developed system and the antitumor activity of MK-7.
At 25 °C, all nanoemulsions remained physically and chemically stable with little change in particle size. An in-vivo study using syngeneic mice with subcutaneously established S180 tumors demonstrated that intravenous or intragastric administration of vitamin K2 nanoemulsions significantly suppressed the tumor growth. The vitamin K2 nanoemulsions modified with sialic acid–cholesterol conjugate showed higher tumor growth suppression than the vitamin K2 nanoemulsions, while neither of them exhibited signs of drug toxicity.
In summary, vitamin K2 as MK-7 exerted effective antitumor effects in vivo, and vitamin K2 nanoemulsions modified with sialic acid–cholesterol conjugate enhanced the antitumor activity, suggesting that vitamin K2 may be promising agents for the prevention or treatment of tumor in patients.
“The problem with conventional tumor therapy pertains to the challenge of delivery. The effectiveness of tumor therapy in solid tumors depends on adequate delivery of therapeutic agents to tumor cells. That is why the authors tested new formulations of MK-7 in vivo,” says Dr. Katarzyna Maresz, president of the International Science and Health Foundation.
“In principle, phylloquinone and menaquinones share growth-inhibitory effects on cancer cells by the modulation of proto-oncogenes that foster cell cycle arrest and apoptosis,” adds Dr. Maresz. “However, the growth-inhibitory potential of menaquinones has been observed to be much much stronger than that of phylloquinone, that is why more often vitamin K2 is used as anticancer agent in many studies in vitro and in vivo.”