The study of bioavailability and endogenous circadian rhythm of menaquinone-7, a form of vitamin K2, in healthy subjects.

Menaquinone-7 (MK-7), a multipotent vitamin K2, possesses a wide range of biological activities, a precise curative effect and excellent safety. A simple and rapid LC-APCI-MS/MS method for the determination of MK-7 in human plasma with single liquid-liquid extraction (LLE) extraction and 4·5-min analysis time has been developed and validated. Four per cent bovine serum albumin (BSA) was used as surrogate matrix for standard curves and endogenous baseline subtraction. This method was reproducible and reliable and was used to analyse of MK-7 in human plasma. The endogenous circadian rhythm and bioavailability of MK-7 were investigated in two randomised single-dose, open, one-way clinical trials (Study I and Study II). A total of five healthy male subjects were enrolled in Study I and 12 healthy male subjects in Study II. Single-dose (1 mg) of MK-7 was given to each subject under fasting condition, and all eligible subjects were given a restricting VK2 diet for 4 d prior to drug administration and during the trial. The experiment results of Study I demonstrated that endogenous MK-7 has no circadian rhythm in individuals. Both studies showed MK-7 are absorbed with peak plasma concentrations at about 6 h after intake and has a very long half-life time.

Effect of Low-Dose Vitamin K2 Supplementation on Bone Mineral Density in Middle-Aged and Elderly Chinese: A Randomized Controlled Study.

Previous studies indicated a positive effect of vitamin K2 (VK2) supplementation on bone turnover biomarkers and bone mineral density (BMD), but the doses varied, and few studies have focused on the difference between VK2 supplementation alone and in combination with calcium and vitamin D3. The aim of this study was to explore a low and effective dose of VK2 for improving BMD, and to examine whether the co-supplementation of VK2, calcium and vitamin D3 would bring greater effects. In this trial, a total of 311 community-dwelling men and postmenopausal women aged 50 and 75 years were randomly assigned to four groups, receiving placebo, 50 µg/day, 90 µg/day or co-supplementation with calcium (500 mg/day) and vitamin D3 (10 µg/day) for 1 year. At the endpoint, the bone loss of femoral neck was significantly lower in postmenopausal women in the two 90 µg groups (treatment × time, p = 0.006) compared with placebo, but no effects in men. Serum biomarkers cOC/ucOC ratio increased in the intervention groups (treatment × time, p < 0.001). VK2 supplementation in dose of 90 µg/day performed a significant effect on reducing bone loss in postmenopausal women, but in combination with calcium and vitamin D3 brought no additional effects.Trial registration This trial was registered at http://www.chictr.org.cn as chiCTR1800019240.

Nattokinase-heparin exhibits beneficial efficacy and safety-an optimal strategy for CKD patients on hemodialysis.

Heparin is a widely used anticoagulant in hemodialysis (HD) for patients with chronic kidney disease (CKD); however, it entails the risk of thrombus formation due to heparin-induced thrombocytopenia. Indeed, CKD patients on HD are associated with excessive mortality from cardiovascular disease due to their prothrombotic profile. Therefore, it would be a significant breakthrough to develop a thrombolytic adjuvant that facilitates heparin to achieve its proper anticoagulant efficiency at a much lower dose for greater safety. Nattokinase (NK), a valuable dietary supplement possessing strong fibrinolytic and thrombolytic activity, was reported to interact with heparin and thereby the beneficial efficacy of NK-heparin was investigated herein. NK-heparin induced a synergistic enhancement of clotting time both in vitro and in vivo evaluations, whereas the overall fibrinolytic activity was only marginally enhanced. Moreover, it was demonstrated for the first time that NK induced potent degradation of all three chains of fibrinogen. In particular, NK-heparin markedly reinforced the fibrinolysis activity of NK, which may underlie, at least in part, the mechanism by which NK-heparin benefited their overall thrombolytic and anticoagulant activity. Collectively, we clarified the beneficial combination efficacy of NK and heparin for greater safety, providing a powerful impetus for physicians to administer heparin to a larger portion of patients with CKD.

Acute toxicity and genotoxicity evaluations of Nattokinase, a promising agent for cardiovascular diseases prevention.

Cardiovascular diseases (CVDs) are the leading cause of death in the world; however, current agents for CVDs prevention are still limited. Owing to the serious bleeding risk of Aspirin, FDA recently recommended against it from preventing first heart attacks. Nattokinase (NK), a serine protease possessing many key beneficial effects on cardiovascular system, is being pursued as a promising alternative agent. In light of this, the safety profile of NK, in particular its potential genotoxicity, need to be characterized. The present study is therefore aimed to evaluate the toxicological profile of NK. To assess acute safety, mice were orally administrated with NK at its maximum concentration and the maximum feeding volume twice in a single day, no mortality or toxicological signs were observed. Hence, the maximum daily tolerant dose of NK in mice is up to 480000 FU/kg, which is 1000 times more compared to the recommended daily dose for human. In the genotoxicity studies, NK showed no mutagenic activity as tested by both Ames test and in vivo micronucleus assay. Moreover, NK demonstrated no evidence of potential to induce chromosome aberrations in CHL cells. These results indicate that there is no safety concern for NK in the present preclinical safety studies, supporting the safety of NK as an agent for CVDs prevention.

Alternol, a natural compound, exerts an anti-tumour effect on osteosarcoma by modulating of STAT3 and ROS/MAPK signalling pathways.

Osteosarcoma (OS) is the most frequent primary malignant bone tumour. Alternol, a novel compound purified from microbial fermentation products exerts anti-tumour effects across several cancer types. The effect of alternol on human OS remains to be elucidated. We first evaluated the anti-tumour effect of alternol in several human OS cell lines in vitro and investigated its underlying mechanism. Alternol inhibited OS cell proliferation, migration and induced caspase-dependent apoptosis, G2/M cell cycle arrest in a dose and time-dependent manner. Moreover, alternol treatment inhibited signal transducer and activator of transcription-3 (STAT3) phosphorylation in 143B and MG63 human OS cells, as evaluated using a STAT3-dependent dual luciferase reporter system. Exposure to alternol resulted in excessive reactive oxygen species (ROS) generation and Jun amino-terminal kinases (JNK), extracellular signal-regulated kinases (ERK1/2) and p38 activation. Furthermore, alternol-induced cell death was significantly restored in the presence of the ROS scavenger, N-acetyl-l-cysteine (NAC) or a caspase inhibitor Z-VAD-FMK. NAC also prevented G2/M phase arrest and phosphorylation of mitogen-activated protein kinases (MAPK), but did not reverse STAT3 inactivation. Finally, alternol suppressed tumour growth in vivo in the nude mouse OS tibia orthotopic model. Immunohistochemistry revealed that alternol treatment resulted in down-regulation of phosph-STAT3 Tyr705 and up-regulation of cleaved caspase-3 and phosph-SAPK (Stress-activated protein kinases)/JNK expression. Taken together, our results reveal that alternol suppresses cell proliferation, migration and induces apoptosis, cell cycle arrest by modulating of ROS-dependent MAPK and STAT3 signalling pathways in human OS cells. Therefore, alternol is a promising candidate for developing anti-tumour drugs target OS.

Alternol inhibits migration and invasion of human hepatocellular carcinoma cells by targeting epithelial-to-mesenchymal transition.

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related deaths worldwide. Such deaths are due, in large part, to its propensity to metastasize. We have examined the effect of alternol on human HCC cells and the underlying molecular mechanism. Therapeutic effects of alternol on cancer cell migration and invasion were analyzed with Boyden chamber and wound healing assays. Effects of alternol on the levels of various proteins involved in cancer cell migration and invasion were determined with gelatin zymography, immunofluorescence, and Western blotting. As shown, treatment with alternol has resulted in a concentration-dependent inhibition of cell migration and invasion of HepG2 cells. The inhibition of HCC invasion by alternol was associated with the suppression of MMP-9 expression and reversal of epithelial-to-mesenchymal transition (EMT). The above results indicated that alternol has the ability to inhibit the migration and invasion of human HCC cells by reversing the process of EMT, suggesting that alternol may be developed as an alternative drug for the treatment of HCC.

Vitamin K: Infection, Inflammation, and Auto-Immunity.

Vitamin K (VK) comprises a group of substances with chlorophyll quinone bioactivity and exists in nature in the form of VK1 and VK2. As its initial recognition originated from the ability to promote blood coagulation, it is known as the coagulation vitamin. However, based on extensive research, VK has shown potential for the prevention and treatment of various diseases. Studies demonstrating the beneficial effects of VK on immunity, antioxidant capacity, intestinal microbiota regulation, epithelial development, and bone protection have drawn growing interest in recent years. This review article focuses on the mechanism of action of VK and its potential preventive and therapeutic effects on infections (eg, asthma, COVID-19), inflammation (eg, in type 2 diabetes mellitus, Alzheimer's disease, Parkinson's disease, cancer, aging, atherosclerosis) and autoimmune disorders (eg, inflammatory bowel disease, type 1 diabetes mellitus, multiple sclerosis, rheumatoid arthritis). In addition, VK-dependent proteins (VKDPs) are another crucial mechanism by which VK exerts anti-inflammatory and immunomodulatory effects. This review explores the potential role of VK in preventing aging, combating neurological abnormalities, and treating diseases such as cancer and diabetes. Although current research appoints VK as a therapeutic tool for practical clinical applications in infections, inflammation, and autoimmune diseases, future research is necessary to elucidate the mechanism of action in more detail and overcome current limitations.

Enhancing Kinetics in Sodium Super Ion Conductor Na3MnTi(PO4)3 through Microbe-Assisted and Structural Optimization.

Sodium (Na) super ion conductor (NASICON) structure Na3MnTi(PO4)3 (NMTP) is considered a promising cathode for sodium-ion batteries due to its reversible three-electron reaction. However, the inferior electronic conductivity and sluggish reaction kinetics limit its practical applications. Herein, we successfully constructed a three-dimensional cross-linked porous architecture NMTP material (AsN@NMTP/C) by a natural microbe of Aspergillus niger (AsN), and the structure of different NMTP cathodes was optimized by adjusting different transition metal Mn/Ti ratios. Both approaches effectively altered the three-dimensional NMTP structure, not only improving electronic conductivity and controlling Na+ diffusion pathways but also enhancing the electrochemical kinetics of the material. The resultant AsN@NMTP/C-650, sintered at 650 °C, exhibits better electrochemical performance with higher reversible three-electron reactions corresponding to the voltage platforms of Ti4+/3+, Mn3+/2+, and Mn4+/3+ around 2.1, 3.6, and 4.1 V (vs Na+/Na), respectively. The capacity retention rate is up to 89.3% after 1000 cycles at a 2C rate. Moreover, a series of results confirms that the Na3.4Mn1.2Ti0.8(PO4)3 cathode has the most excellent electrochemical performance when the Mn/Ti ratio is 1.2/0.8, with a high capacity of 96.59 mAh g-1 and 97.1% capacity retention after 500 cycles.

Nattokinase Promotes Post-stroke Neurogenesis and Cognition Recovery via Increasing Circulating Irisin.

The therapeutic potential of treatments for post-stroke cognitive impairment (PSCI) is severely limited by the autonomic regeneration capacity of the adult brain. Nattokinase (NK), a serine protease from the traditional food natto, has many beneficial effects on the cardiovascular system by modulating the blood system. While the role of blood factors in neurogenesis and cognition is well-established, it remains unclear whether NK can serve as an anti-PSCI agent through these factors. Our study demonstrates that NK protects against acute ischemic stroke and impressively promotes neurogenesis in rat models by increasing peripheral blood irisin, leading to improved cognitive functions. Our findings demonstrate NK to be a promising candidate for treating PSCI, and we also highlight irisin as a novel target of NK, suggesting its potential role in the peripheral blood-to-brain axis.

Vitamin K2 (MK-7) attenuates LPS-induced acute lung injury via inhibiting inflammation, apoptosis, and ferroptosis.

Acute lung injury (ALI) is a life-threatening disease that has received considerable critical attention in the field of intensive care. This study aimed to explore the role and mechanism of vitamin K2 (VK2) in ALI. Intraperitoneal injection of 7 mg/kg LPS was used to induce ALI in mice, and VK2 injection was intragastrically administered with the dose of 0.2 and 15 mg/kg. We found that VK2 improved the pulmonary pathology, reduced myeloperoxidase (MPO) activity and levels of TNF-α and IL-6, and boosted the level of IL-10 of mice with ALI. Moreover, VK2 played a significant part in apoptosis by downregulating and upregulating Caspase-3 and Bcl-2 expressions, respectively. As for further mechanism exploration, we found that VK2 inhibited P38 MAPK signaling. Our results also showed that VK2 inhibited ferroptosis, which manifested by reducing malondialdehyde (MDA) and iron levels, increasing glutathione (GSH) level, and upregulated and downregulated glutathione peroxidase 4 (GPX4) and heme oxygenase-1 (HO-1) expressions, respectively. In addition, VK2 also inhibited elastin degradation by reducing levels of uncarboxylated matrix Gla protein (uc-MGP) and desmosine (DES). Overall, VK2 robustly alleviated ALI by inhibiting LPS-induced inflammation, apoptosis, ferroptosis, and elastin degradation, making it a potential novel therapeutic candidate for ALI.

Corrigendum: Effective management of atherosclerosis progress and hyperlipidemia with nattokinase: A clinical study with 1,062 participants.

[This corrects the article DOI: 10.3389/fcvm.2022.964977.].

Effective management of atherosclerosis progress and hyperlipidemia with nattokinase: A clinical study with 1,062 participants.

Nattokinase (NK), known as a potent fibrinolytic and antithrombotic agent, has been shown to have antiatherosclerotic and lipid-lowering effects. However, data on human clinical studies are limited. In this clinical study involving 1,062 participants, our objective was to examine the efficacy of NK in atherosclerosis and hyperlipidemia and safety at the dose of 10,800 FU/day after 12 months of oral administration. Various factors, including lower doses that influence NK pharmacological actions, were also investigated. We found that NK at a dose of 10,800 FU/day effectively managed the progression of atherosclerosis and hyperlipidemia with a significant improvement in the lipid profile. A significant reduction in the thickness of the carotid artery intima-media and the size of the carotid plaque was observed. The improvement rates ranged from 66.5 to 95.4%. NK was found to be ineffective in lowering lipids and suppressing atherosclerosis progression at a dose of 3,600 FU/day. The lipid-lowering effect of NK was more prominent in subjects who smoked, drank alcohol, and subjects with higher BMI. Regular exercise further improved the effects of NK. Co-administration of vitamin K2 and aspirin with NK produced a synergetic effect. No noticeable adverse effects associated with the use of NK were recorded. In conclusion, our data demonstrate that atherosclerosis progression and hyperlipidemia can be effectively managed with NK at a dose of 10,800 FU/day. The lower dose of 3,600 FU per day is ineffective. The dose of 10,800 FU/day is safe and well tolerated. Some lifestyle factors and the coadministration of vitamin K2 and aspirin lead to improved outcomes in the use of NK. Our findings provide clinical evidence on the effective dose of NK in the management of cardiovascular disease and challenge the recommended dose of 2,000 FU per day.

Role of emerging vitamin K­dependent proteins: Growth arrest­specific protein 6, Gla­rich protein and periostin (Review).

Vitamin K­dependent proteins (VKDPs) are a group of proteins that need vitamin K to conduct carboxylation. Thus far, scholars have identified a total of 17 VKDPs in the human body. In this review, we summarize three important emerging VKDPs: Growth arrest­specific protein 6 (Gas 6), Gla­rich protein (GRP) and periostin in terms of their functions in physiological and pathological conditions. As examples, carboxylated Gas 6 and GRP effectively protect blood vessels from calcification, Gas 6 protects from acute kidney injury and is involved in chronic kidney disease, GRP contributes to bone homeostasis and delays the progression of osteoarthritis, and periostin is involved in all phases of fracture healing and assists myocardial regeneration in the early stages of myocardial infarction. However, periostin participates in the progression of cardiac fibrosis, idiopathic pulmonary fibrosis and airway remodeling of asthma. In addition, we discuss the relationship between vitamin K, VKDPs and cancer, and particularly the carboxylation state of VKDPs in cancer.

Alternol/Alteronol: Potent Anti-cancer Compounds With Multiple Mechanistic Actions.

Alternol and its oxidate isomer Alteronol are small compounds isolated from the fermentation of a mutant fungus obtained from Taxus brevifolia bark. Preclinical studies showed their potent anti-cancer activities, including attenuating cellular survival pathways, altering protein levels of cell cycle regulators, activating xanthine dehydrogenase to cause accumulation of cellular reactive oxygen species and disrupting cell metabolism by disturbing four Krebs cycle enzymes specifically in malignant cells while having no significant effect on benign cells. In cancer cell culture models, Alternol or Alteronol exert their anti-cancer effect by inducing cell cycle arrest and triggering apoptotic cell death. In mice xenograft models, Alternol or Alteronol potently suppresses tumor growth with no obvious toxicity to the host with a wide therapeutic index over 30-fold. In conclusion, Alternol or Alteronol possess a great potential and feasibility to be developed as an effective anti-tumor therapeutic.

Breaking the vicious loop between inflammation, oxidative stress and coagulation, a novel anti-thrombus insight of nattokinase by inhibiting LPS-induced inflammation and oxidative stress.

Thrombosis is a principle cause of cardiovascular disease, the leading cause of morbidity and mortality worldwide; however, the conventional anti-thrombotic approach often leads to bleeding complications despite extensive clinical management and monitoring. In view of the intense crosstalk between inflammation and coagulation, plus the contributing role of ROS to both inflammation and coagulation, it is highly desirable to develop safer anti-thrombotic agent with preserved anti-inflammatory and anti-oxidative stress activities. Nattokinase (NK) possesses many beneficial effects on cardiovascular system due to its strong thrombolytic and anticoagulant activities. Herein, we demonstrated that NK not only effectively prevented xylene-induced ear oedema in mice, but also remarkably protected against LPS-induced acute kidney injury in mice through restraining inflammation and oxidative stress, a central player in the initiation and progression of inflammation. Fascinatingly, in line with our in vivo data, NK elicited prominent anti-inflammatory activity in RAW264.7 macrophages via suppressing the LPS-induced TLR4 and NOX2 activation, thereby repressing the corresponding ROS production, MAPKs activation, and NF-κB translocation from the cytoplasm to the nucleus, where it mediates the expression of pro-inflammatory mediators, such as TNF-α, IL-6, NO, and PAI-1 in activated macrophage cells. In particular, consistent with the macrophage studies, NK markedly inhibited serum PAI-1 levels induced by LPS, thereby blocking the deposition of fibrin in the glomeruli of endotoxin-treated animals. In summary, we extended the anti-thrombus mechanism of NK by demonstrating the anti-inflammatory and anti-oxidative stress effects of NK in ameliorating LPS-activated macrophage signaling and protecting against LPS-stimulated AKI as well as glomeruler thrombus in mice, opening a comprehensive anti-thrombus strategy by breaking the vicious cycle between inflammation, oxidative stress and thrombosis.

Development of a nattokinase-polysialic acid complex for advanced tumor treatment.

Cancer-associated thrombus (CAT) impedes delivery of nanoparticles to tumor sites and also inhibits the ability of immune cells to detect and attack these tumors, particularly in advanced tumors with old thrombi. Nattokinase (NK) is an extract from a popular Japanese food, natto, which consists of boiled soybeans fermented with bacteria. Nattokinase exerts strong fibrinolytic and thrombolytic activities and can unblock blood vessels. To deliver NK to thrombus sites in tumors, we modified the surface of NK with polysialic acid (PSA), which formed complexes via electrostatic interactions, resulting in NK-PSA. Particle size and zeta potential of NK-PSA were evaluated, and differential scanning calorimetry, Fourier-transform infrared spectroscopy, and morphological analyses of NK-PSA were performed. To determine the efficacy of the NK-PSA complex on delivery of nanoparticulate drugs, sialic acid-modified doxorubicin liposomes (DOX-SAL) were used as a model drug. In vivo pharmacokinetic and tissue distribution analyses showed that the blood clearance rate of DOX-SAL was significantly enhanced by NK-PSA, and NK-PSA increased accumulation of 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide (DiR) labeled SAL (DiR-SAL) in tumors. Analysis of anti-tumor efficacy showed that the combination of NK-PSA and DOX-SAL enhanced anti-tumor activity. These results suggested that NK-PSA combined with DOX-SAL may be an effective strategy to clear CAT and increase the ability of nanoparticles and immune cells to reach tumors.

Inhibition of human gastric carcinoma cell growth in vitro and in vivo by cladosporol isolated from the paclitaxel-producing strain Alternaria alternata var. monosporus.

Cladosporol was isolated from the fermentation broth of Alternaria alternata var. monosporus obtained from the inner bark of the yew tree and mutated for many generations. We investigated the antitumor effects of cladosporol in vitro and in vivo. The growth-inhibitory effects of cladosporol in vitro against six human cancer cell lines were examined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The results showed that cladosporol selectively killed cancer cells and had a significant inhibitory effect on the human gastric carcinoma cell line MGC-803 in a concentration- and time-dependent manner. In vivo, cladosporol also showed antitumor activity in nude mice bearing MGC-803 gastric cancer xenografts. These findings suggest that cladosporol has potentially useful growth inhibitory effects on human gastric carcinoma cell lines.

Research progress on the anticancer effects of vitamin K2.

Despite the availability of multiple therapeutic methods for patients with cancer, the long-term prognosis is not satisfactory in a number of different cancer types. Vitamin K2 (VK2), which exerts anticancer effects on a number of cancer cell lines, is considered to be a prospective novel agent for the treatment of cancer. The present review aims to summarize the results of studies in which VK2 was administered either to patients with cancer or animals inoculated with cancerous cells, particularly investigating the inhibitory effects of VK2 on cancerous cells, primarily involving cell-cycle arrest, cell differentiation, apoptosis, autophagy and invasion. The present review summarizes evidence stating that treatment with VK2 could positively inhibit the growth of cancer cells, making it a potentially useful approach for the prevention and clinical treatment of cancer. Additionally, the combination treatment of VK2 and established chemotherapeutics may achieve better results, with fewer side effects. Therefore, more attention should be paid to the effects of micronutrients on tumors.

Vitamin K­dependent proteins involved in bone and cardiovascular health (Review).

In postmenopausal women and elderly men, bone density decreases with age and vascular calcification is aggravated. This condition is closely associated with vitamin K2 deficiency. A total of 17 different vitamin K­dependent proteins have been identified to date. Vitamin K­dependent proteins are located within the bone, heart and blood vessels. For instance, carboxylated osteocalcin is beneficial for bone and aids the deposition of calcium into the bone matrix. Carboxylated matrix Gla protein effectively protects blood vessels and may prevent calcification within the vascular wall. Furthermore, carboxylated Gla­rich protein has been reported to act as an inhibitor in the calcification of the cardiovascular system, while growth arrest­specific protein­6 protects endothelial cells and vascular smooth muscle cells, resists apoptosis and inhibits the calcification of blood vessels by inhibiting the apoptosis of vascular smooth muscle cells. In addition, periostin may promote the differentiation, aggregation, adhesion and proliferation of osteoblasts. Periostin also occurs in the heart and may be associated with the reconstruction of heart function. These vitamin K­dependent proteins may exert their functions following γ­carboxylation with vitamin K, and different vitamin K­dependent proteins may exhibit synergistic effects or antagonistic effects on each other. In the cardiovascular system with vitamin K antagonist supplement or vitamin K deficiency, calcification occurs in the endothelium of blood vessels and vascular smooth muscle cells are transformed into osteoblast­like cells, a phenomenon that resembles bone growth. Both the bone and cardiovascular system are closely associated during embryonic development. Thus, the present study hypothesized that embryonic developmental position and tissue calcification may have a certain association for the bone and the cardiovascular system. This review describes and briefly discusses several important vitamin K­dependent proteins that serve an important role in bone and the cardiovascular system. The results of the review suggest that the vascular calcification and osteogenic differentiation of vascular smooth muscle cells may be associated with the location of the bone and cardiovascular system during embryonic development.

Evaluation of the antitumor effects of vitamin K2 (menaquinone-7) nanoemulsions modified with sialic acid-cholesterol conjugate.

Numerous studies have recently shown that vitamin K2 (VK2) has antitumor effects in a variety of tumor cells, but there are few reports demonstrating antitumor effects of VK2 in vivo. The antitumor effects of VK2 in nanoemulsions are currently not known. Therefore, we sought to characterize the antitumor potential of VK2 nanoemulsions in S180 tumor cells in the present study. Furthermore, a ligand conjugate sialic acid-cholesterol, with enhanced affinity towards the membrane receptors overexpressed in tumors, was anchored on the surface of the nanoemulsions to increase VK2 distribution to the tumor tissue. VK2 was encapsulated in oil-in-water nanoemulsions, and the physical and chemical stability of the nanoemulsions were characterized during storage at 25 °C. 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 VK2 nanoemulsions significantly suppressed the tumor growth. The VK2 nanoemulsions modified with sialic acid-cholesterol conjugate showed higher tumor growth suppression than the VK2 nanoemulsions, while neither of them exhibited signs of drug toxicity. In summary, VK2 exerted effective antitumor effects in vivo, and VK2 nanoemulsions modified with sialic acid-cholesterol conjugate enhanced the antitumor activity, suggesting that these VK2 may be promising agents for the prevention or treatment of tumor in patients.