Anti-inflammatory effect of the extracts from the branch of Taxillus yadoriki being parasitic in Neolitsea sericea in LPS-stimulated RAW264.7 cells.

Mistletoe has been used as the herbal medicine to treat hypertension, diabetes mellitus, inflammation, arthritis and viral infection. In this study, we evaluated the anti-inflammatory effect of extracts of branch from Taxillus yadoriki being parasitic in Neolitsea sericea (TY-NS-B) using in vitro model. TY-NS-B significantly inhibited LPS-induced secretion of NO and PGE2 in RAW264.7 cells. TY-NS-B was also observed to inhibit LPS-mediated iNOS COX-2 expression. In addition, TY-NS-B attenuated production of inflammatory cytokines such as TNF-α and IL-1ß induced by LPS. TY-NS-B blocked LPS-mediated inhibitor of IκB-α, and inhibited p65 translocation to the nucleus and NF-κB activation. Furthermore, TY-NS-B reduced the phosphorylation of MAPKs such as p38 and JNK, but not ERK1/2. In addition, TY-NS-B increased ATF3 expression and ATF3 knockdown by ATF3 siRNA attenuated TY-NS-B-mediated inhibition of pro-inflammatory mediator expression. Collectively, our results suggest that TY-NS-B exerts potential anti-inflammatory effects by suppressing NF-κB and MAPK signaling activation, and increasing ATF3 expression. These findings indicate that TY-NS-B could be further developed as an anti-inflammatory drug.

Vitex rotundifolia Fruit Extract Induces Apoptosis Through the Downregulation of ATF3-Mediated Bcl-2 Expression in Human Colorectal Cancer Cells.

Fruit from Vitex rotundifolia L. (VF) has been reported to initiate apoptosis in human colorectal cancer cells through the accumulation of reactive oxygen species. Since various regulatory factors are involved in the apoptotic pathway, further study of the potential mechanisms of VF associated with the induction of apoptosis may be important despite the fact that the molecular target of VF for apoptosis has already been elucidated. In this study, we showed a new potential mechanism for the relationship between VF-mediated ATF3 expression and apoptosis to better understand the apoptotic mechanism of VF in human colorectal cancer cells. VF reduced the cell viability and induced apoptosis in human colorectal cancer cells. VF treatment increased both the protein and mRNA level of ATF3 and upregulated ATF3 promoter activity. The cis-element responsible for ATF3 transcriptional activation by VF was CREB which is located between [Formula: see text]147 to [Formula: see text]85 of ATF3 promoter. Inhibitions of ERK1/2, p38, JNK and GSK3[Formula: see text] blocked VF-mediated ATF3 expression. ATF3 knockdown by ATF3 siRNA attenuated the cleavage of PARP by VF, while ATF3 overexpression increased VF-mediated cleaved PARP. ATF3 knockdown also attenuated VF-mediated cell viability and cell death. In addition, VF downregulated Bcl-2 expression at both protein and mRNA level. ATF3 knockdown by ATF3 siRNA blocked VF-mediated downregulation of Bcl-2. In conclusion, VF may activate ATF3 expression through transcriptional regulation and subsequently suppress Bcl-2 expression as an anti-apoptotic protein, which may result in the induction of apoptosis in human colorectal cancer cells.

Anti-cancer activity of Bacillus amyloliquefaciens AK-0 through cyclin D1 proteasomal degradation via GSK3ß-dependent phosphorylation of threonine-286.

Microorganisms have been regarded as important sources of novel bioactive natural products. In this study, we evaluated the anti-cancer activity and the potential mechanism of Bacillus amyloliquefaciens AK-0 newly isolated from the rhizosphere soil of Korean ginseng. The ethyl acetate fraction from the culture medium of B. amyloliquefaciens AK-0 (EA-AK0) inhibited markedly the proliferation of human colorectal cancer cells such as HCT116, SW480, LoVo and HT-29. EA-AK0 effectively decreased cyclin D1 protein level in human colorectal cancer cells, while cyclin D1 mRNA level was not changed by EA-AK0 treatment. Inhibition of proteasomal degradation by MG132 blocked EA-AK0-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in the cells treated with MRB. In addition, EA-AK0 increased threonine-286 (T286) phosphorylation of cyclin D1, and a point mutation of T286 to alanine attenuated cyclin D1 degradation by EA-AK0. Inhibition of GSK3ß by LiCl suppressed cyclin D1 phosphorylation and downregulation by EA-AKO. From these results, EA-AK0 may suppress the proliferation of human colorectal cancer cells by inducing cyclin D1 proteasomal degradation through GSK3ß-dependent T286 phosphorylation. These results indicate that EA-AK0 could be used for treating colorectal cancer and serve as a potential candidate for anticancer drug development. In addition, these findings will be helpful for expanding the knowledge on the molecular anti-cancer mechanisms of EA-AK0.

Arctigenin induces cell cycle arrest by blocking the phosphorylation of Rb via the modulation of cell cycle regulatory proteins in human gastric cancer cells.

Gastric cancer is a leading cause of cancer-related deaths, worldwide being second only to lung cancer as a cause of death. Arctigenin, a representative dibenzylbutyrolactone lignan, occurs in a variety of plants. However, the molecular mechanisms of arctigenin for anti-tumor effect on gastric cancer have not been examined. This study examined the biological effects of arctigenin on the human gastric cancer cell line SNU-1 and AGS. Cell proliferation was determined by MTT assay. In MTT assay, the proliferation of SNU-1 and AGS cells was significantly inhibited by arctigenin in a time and dose dependent manner, as compared with SNU-1 and AGS cells cultured in the absence of arctigenin. Inhibition of cell proliferation by arctigenin was in part associated with apoptotic cell death, as shown by changes in the expression ratio of Bcl-2 to Bax by arctigenin. Also, arctigenin blocked cell cycle arrest from G(1) to S phase by regulating the expression of cell cycle regulatory proteins such as Rb, cyclin D1, cyclin E, CDK4, CDK2, p21Waf1/Cip1 and p15 INK4b. The antiproliferative effect of arctigenin on SNU-1 and AGS gastric cancer cells revealed in this study suggests that arctigenin has intriguing potential as a chemopreventive or chemotherapeutic agent.

Diosgenin stimulates osteogenic activity by increasing bone matrix protein synthesis and bone-specific transcription factor Runx2 in osteoblastic MC3T3-E1 cells.

Diosgenin, a steroid saponin extracted from the root of wild yam (Dioscorea villossa) is claimed to have osteogenic property. However, detailed studies providing evidence to this claim have not been fully undertaken. In this study, we investigated the effect of diosgenin on the osteogenesis of murine MC3T3-E1 osteoblastic cells. Cells were cultured with varying levels of diosgenin (0-10 µM) within 25 days of bone formation period. Diosgenin was found to stimulate proliferation within the range of 0.01-5 µM using MTT assay. The medium and cellular levels of Type 1 collagen and alkaline phosphatase (ALP), both of which are major bone matrix proteins, increased within the low range of diosgenin concentration (>0-3 µM), and this pattern was further confirmed by collagen and ALP staining of the extracellular matrix (ECM). The cellular protein expression of ALP and collagen Type 1 was also increased at 0.1-1 µM diosgenin treatment as analyzed by Western blot. Calcium deposition within the ECM also showed the same pattern as assessed by Alizarin Red S and Von Kossa staining. Bone-specific transcription factor runt-related transcription factor 2 (Runx2) and Runx2-regulated osteopontin protein expressions were induced at low concentration (0.1-1 µM) and again decreased with high diosgenin concentrations. Based on our findings, our study suggests that diosgenin can enhance bone formation by stimulating the synthesis and secretion of Type 1 collagen and ALP and bone marker proteins Runx2 and osteopontin expression. The increased levels of these marker proteins, in turn, can increase the formation of calcium deposits within the ECM thereby increasing bone formation.

Anti-inflammatory effect of 2-methoxy-4-vinylphenol via the suppression of NF-κB and MAPK activation, and acetylation of histone H3.

Although inflammation acts as host defense mechanism against infection or injury and is primarily a self limiting process, inadequate resolution of inflammatory responses leads to various chronic disorders. This work aimed to elucidate the anti-inflammatory effects of 2-methoxy-4-vinylphenol (2M4VP) isolated from pine needles in LPS-stimulated RAW264.7 cells. Some key pro-inflammatory mediators including nitric oxide (NO), prostaglandins (PGE(2)), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2) were studied by sandwich ELISA and western blot. In addition, suppression of NF-κB and MAPK activation, and histone acetylation was studied by western blot analysis and immunostaining. 2M4VP dosedependently inhibited NO and PGE(2) production and also blocked LPS-induced iNOS and COX-2 expression. In addition, 2M4VP potently inhibited the translocation of NF-κB p65 into the nucleus by IκB degradation following IκB-α phosphorylation and the phosphorylation of MAPKs such as p38, ERK1/2, and JNK. Also, 2M4VP inhibited hyper-acetylation of histone H3 (Lys9/Lys14) induced by LPS. Taken together, our results suggest that 2M4VP, a naturally occurring phenolic compound, exert potent anti-inflammatory effects by inhibiting LPS-induced NO, PGE(2), iNOS, and COX-2 in RAW264.7 cells. These effects are mediated by suppression of NF-κB and MAPK activation and histone acetylation.

Lunasin is prevalent in barley and is bioavailable and bioactive in in vivo and in vitro studies.

Lunasin, a unique 43-amino acid peptide found in a number of seeds, has been shown to be chemopreventive in mammalian cells and in a skin cancer mouse model. To elucidate the role of cereals in cancer prevention, we report here the prevalence, bioavailability, and bioactivity of lunasin from barley. Lunasin is present in all cultivars of barley analyzed. The liver and kidney of rats fed with lunasin-enriched barley (LEB) show the presence of lunasin in Western blot. Lunasin extracted from the kidney and liver inhibits the activities of HATs (histone acetyl transferases), yGCN5 by 20% and 18% at 100 nM, and PCAF activity by 25% and 24% at 100 nM, confirming that the peptide is intact and bioactive. Purified barley lunasin localizes in the nuclei of NIH 3T3 cells. Barley lunasin added to NIH 3T3 cells in the presence of the chemical carcinogen MCA activates the expression of tumor suppressors p21 and p15 by 45% and 47%, decreases cyclin D1 by 98%, and inhibits Rb hyperphosphorylation by 45% compared with the MCA treatment alone. We conclude that lunasin is prevalent in barley, bioavailable, and bioactive and that consumption of barley could play an important role of cancer prevention in barley-consuming populations.

2-Methoxy-4-vinylphenol can induce cell cycle arrest by blocking the hyper-phosphorylation of retinoblastoma protein in benzo[a]pyrene-treated NIH3T3 cells.

Benzo[a]pyrene (BaP) is an environment carcinogen that can enhance cell proliferation by disturbing the signal transduction pathways in cell cycle regulation. In this study, the effects of 2M4VP on cell proliferation, cell cycle and cell cycle regulatory proteins were studied in BaP-treated NIH 3T3 cells to establish the molecular mechanisms of 2M4VP as anti-proliferative agents. 2M4VP exerted a dose-dependent inhibitory effect on cell growth correlated with a G1 arrest. Analysis of G1 cell cycle regulators expression revealed 2M4VP increased expression of CDK inhibitor, p21Waf1/Cip1 and p15 INK4b, decreased expression of cyclin D1 and cyclin E, and inhibited kinase activities of CDK4 and CDK2. However, 2M4VP did not affect the expression of CDK4 and CDK2. Also, 2M4VP inhibited the hyper-phosphorylation of Rb induced by BaP. Our results suggest that 2M4VP induce growth arrest of BaP-treated NIH 3T3 cells by blocking the hyper-phosphorylation of Rb via regulating the expression of cell cycle-related proteins.

Amaranth lunasin-like peptide internalizes into the cell nucleus and inhibits chemical carcinogen-induced transformation of NIH-3T3 cells.

Because an unbalanced diet is an important risk factor for several illnesses, interest has increased in finding novel health-promoting foods. Amaranth produces seeds that not only have substantial nutritional properties but that also contain phytochemical compounds as rutin and nicotiflorin and peptides with antihypertensive and anticarcinogenic activities. We report that a cancer-preventive peptide in amaranth has activities similar to those of soybean lunasin. The amaranth lunasin-like peptide, however, requires less time than the soybean lunasin to internalize into the nucleus of NIH-3T3 cells, and inhibits histone acetylation (H(3) and H(4) in a 70 and 77%, respectively). The amaranth lunasin-like peptide inhibited the transformation of NIH-3T3 cells to cancerous foci. The open reading frame (ORF) of amaranth lunasin corresponds to a bifunctional inhibitor/lipid-transfer protein (LTP). LTPs are a family of proteins that in plants are implicated in different functions, albeit all linked to developmental processes and biotic and abiotic stress resistance. Our results open new intriguing questions about the function of lunasin in plants and support that amaranth is a food alternative containing natural peptides with health-promoting benefits.

Rheosmin, a naturally occurring phenolic compound inhibits LPS-induced iNOS and COX-2 expression in RAW264.7 cells by blocking NF-kappaB activation pathway.

Inflammation is part of the host defense mechanism against harmful matters and injury; however, aberrant inflammation is associated to the development of chronic disease such as cancer. Raspberry ketone is a natural phenolic compound. It is used in perfumery, in cosmetics, and as a food additive to impart a fruity odor. In this study, we evaluated whether rheosmin, a phenolic compound isolated from pine needles regulates the expression of iNOS and COX-2 protein in LPS-stimulated RAW264.7 cells. Rheosmin dose-dependently inhibited NO and PGE(2) production and also blocked LPS-induced iNOS and COX-2 expression. Rheosmin potently inhibited the translocation of NF-kappaB p65 into the nucleus by IkappaB degradation following IkappaB-alpha phosphorylation. This result shows that rheosmin inhibits NF-kappaB activation. In conclusion, our results suggest that rheosmin inhibits LPS-induced iNOS and COX-2 expression in RAW264.7 cells by blocking NF-kappaB activation pathway.

Lunasin peptide purified from Solanum nigrum L. protects DNA from oxidative damage by suppressing the generation of hydroxyl radical via blocking fenton reaction.

Oxidative DNA damage is the most critical factor implicated in carcinogenesis and other disorders. However, the protective effects of lunasin against oxidative DNA damage have not yet reported. In this study, we report here the protective effect of lunasin purified from Solanum nigrum L. against oxidative DNA. Lunasin protected DNA from the oxidative damage induced by Fe(2+) ion and hydroxyl radical. To better understand the mechanism for the protective effect of lunasin against DNA damage, the abilities to chelate Fe(2+), scavenge the generated hydroxyl radical and block the generation of hydroxyl radical were evaluated. Although it did not scavenge generated hydroxyl radical, lunasin blocked the generation of hydroxyl radical by chelating Fe(2+) ion. We conclude that lunasin protects DNA from oxidation by blocking fenton reaction between Fe(2+) and H(2)O(2) by chelating Fe(2+) and that consumption of lunasin may play an important role in the chemoprevention for the oxidative carcinogenesis.

The cancer preventive seed peptide lunasin from rye is bioavailable and bioactive.

Lunasin is a unique 43-amino acid peptide that has been shown to be chemopreventive in mammalian cells and in a skin cancer mouse model against oncogenes and chemical carcinogens. In search for new sources of lunasin and to better understand the role of cereals in cancer prevention, we report here the properties of lunasin from rye. The stability and bioavailability were measured by in vitro digestibility assay using pepsin and pancreatin and feeding rats with lunasin-enriched rye (LER). Inhibition of histone acetyl transferase (HAT) and nuclear localization in mammalian cells were used to measure lunasin bioactivity. Lunasin is present in 15 out of 21 cultivars of rye analyzed. Lunasin present in rye crude protein preparation is stable to pepsin and pancreatin in in vitro digestion. The liver, kidney, and blood of rats fed LER show the presence of lunasin in Western blot. Lunasin extracted from these tissues inhibits the activities of HATs, confirming that the peptide is intact and bioactive. Lunasin purified from rye internalizes in the nuclei of mouse fibroblast cells. We conclude that lunasin in rye is bioavailable and bioactive and that consumption of rye may play an important role of cancer prevention in rye-consuming populations.

Antioxidant activity in essential oils of Cnidium officinale makino and Ligusticum chuanxiong Hort and their inhibitory effects on DNA damage and apoptosis induced by ultraviolet B in mammalian cell.

BACKGROUND: Owing to their high volatile aroma, the dried rhizomes of Cnidium officinale (C. officinale) and Ligusticum chuanxiong (L. chuanxiong) are used as herbal drugs to treat blood pressure depressant, a deficiency disease of antivitamin, inhibition of small intestine sympathetic nerve and as cosmetics for skin care. However, little has been known about the protective effect of their essential oils against ultraviolet B (UVB)-induced DNA damage. METHODS: In this study, we report antioxidant activity of their essential oils using DPPH and ABTS scavenging assay. In addition, the composition of essential oils was measured by GC/MS. We also investigated whether these essential oils could inhibit UVB-induced DNA damage and apoptosis in the mammalian cell using intracellular DNA migration and expression level of phospho-H2A.X. RESULTS: Twenty constituents in the essential oil were identified and they showed good antioxidant properties, in that IC(50) value in DPPH and ABTS showed 6.79 and 7.33microg/ml and 1.58 and 1.58microg/ml in C. officinale and L. chuanxiong. Their treatment inhibited the migration of damaged DNA induced by UV-B; furthermore, they decreased p21 expression and increased cyclin D1 expression as apoptosis-regulatory genes. CONCLUSIONS: These results suggest that essential oils in C. officinale and L. chuanxiong may exert inhibitory effects on DNA damage and apoptosis induced by UVB through their high free radical scavenging ability.

Effect of extracts from pine needle against oxidative DNA damage and apoptosis induced by hydroxyl radical via antioxidant activity.

In this study, the protective effects of water extracts from pine needle (WEPN) against DNA damage and apoptosis induced by hydroxyl radical were investigated in non-cellular and cellular system. WEPN exhibited strong scavenging action on hydroxyl radical and intracellular ROS, and chelating action of Fe(2+) ion. WEPN inhibited oxidative DNA damage by hydroxyl radical. Also, WEPN prevented the cells from oxidative damage through lowering p21 and BAX protein expression, blocking the cleavage of PARP and increasing Bcl-2 protein, which was confirmed by Hoechst 33342 staining. These data indicate that WEPN possesses a spectrum of antioxidant and DNA-protective properties common to cancer chemopreventive agents.

Protective effect of the extracts from Cnidium officinale against oxidative damage induced by hydrogen peroxide via antioxidant effect.

The dried rhizomes of Cnidium officinale are used as herbal drugs in the treatment of pain, inflammation, menstrual disturbance and antivitamin deficiency disease, and also act as a blood pressure depressant. In addition, there are several reports suggesting that they have pharmacological properties to tumor metastasis and angiogenesis, and that they act as an inhibitor of high glucose-induced proliferation of glomerular mesangial cells. However, little has been known about the functional role of the extracts from C. officinale on oxidative DNA damage and apoptosis caused by ROS. In this work, we have investigated the DPPH radical, hydroxyl radical and intracellular ROS scavenging capacity, and Fe(2+) chelating activity of the extracts from C. officinale. In addition, we evaluated whether the extracts are capable of reducing H(2)O(2)-induced DNA and cell damage in the human skin fibroblast cell. These extracts showed a dose-dependent free-radical scavenging capacity and a protective effect on DNA damage and the lipid peroxidation causing the cell damage by ROS. These antioxidant activities and inhibitory effects of the extracts on DNA and cell damage may further explain that C. officinale is useful as a herbal medicine for cancer chemoprevention.

3,4-dihydroxybenzaldehyde purified from the barley seeds (Hordeum vulgare) inhibits oxidative DNA damage and apoptosis via its antioxidant activity.

Barley is a major crop worldwide. It has been reported that barley seeds have an effect on scavenging ROS. However, little has been known about the functional role of the barley on the inhibition of DNA damage and apoptosis by ROS. In this study, we purified 3,4-dihydroxybenzaldehyde from the barley with silica gel column chromatography and HPLC and then identified it by GC/MS. And we firstly investigated the inhibitory effects of 3,4-dihydroxybenzaldehyde purified from the barley on oxidative DNA damage and apoptosis induced by H(2)O(2), the major mediator of oxidative stress and a potent mutagen. In antioxidant activity assay such as DPPH radical and hydroxyl radical scavenging assay, Fe(2+) chelating assay, and intracellular ROS scavenging assay by DCF-DA, 3,4-dihydroxybenzaldehyde was found to scavenge DPPH radical, hydroxyl radical and intracellular ROS. Also it chelated Fe(2+). In in vitro oxidative DNA damage assay and the expression level of phospho-H2A.X, it inhibited oxidative DNA damage and its treatment decreased the expression level of phospho-H2A.X. And in oxidative cell death and apoptosis assay via MTT assay and Hoechst 33342 staining, respectively, the treatment of 3,4-dihydroxybenzaldehyde attenuated H(2)O(2)-induced cell death and apoptosis. These results suggest that the barley may exert the inhibitory effect on H(2)O(2)-induced tumor development by blocking H(2)O(2)-induced oxidative DNA damage, cell death and apoptosis.

In vitro digestibility of the cancer-preventive soy peptides lunasin and BBI.

Lunasin and BBI (Bowman Birk protease inhibitor) are bioactive soy peptides that have been shown to be effective suppressors of carcinogenesis in in vitro and in vivo model systems. Since they are subject to digestion in the gastrointestinal tract, we investigated here the stabilities of lunasin and BBI to digestion in vitro by simulated intestinal fluid (SIF) and simulated gastric fluid (SGF). Samples containing lunasin and BBI of varying purities were subjected to in vitro digestion by SIF and SGF at different times and analyzed by Western blot. While the pure BBI reaction is stable after SIF and SGF digestions, the purified lunasin from soybean and synthetic lunasin are easily digested after 2 min in both in vitro digestions. In contrast, lunasin from soy protein containing BBI is comparatively stable after SIF and SGF digestions. Both lunasin and BBI are able to internalize into the cell and localize in the nucleus even after digestion, suggesting that some of the peptides are intact and bioactive. These data suggest that BBI plays a role in protecting lunasin from digestion when soy protein is consumed orally. The role of other soy protease inhibitors such as Kunitz Trypsin Inhibitor (KTI) cannot be excluded from these experiments.

Cancer-preventive peptide lunasin from Solanum nigrum L. inhibits acetylation of core histones H3 and H4 and phosphorylation of retinoblastoma protein (Rb).

Lunasin, a unique 43 amino acid, 4.8 kDa cancer-chemopreventive peptide initially reported in soybean and now found in barley and wheat, has been shown to be cancer-chemopreventive in mammalian cells and in a skin cancer mouse model against oncogenes and chemical carcinogens. To identify bioactive components in traditional herbal medicines and in search for new sources of lunasin, we report here the properties of lunasin from Solanum nigrum L. (SNL), a plant indigenous to northeast Asia. Lunasin was screened in the crude extracts of five varieties of the medicinal plants of Solanaceae origin and seven other major herbal plants. An in vitro digestion stability assay for measuring bioavailability was carried out on SNL crude protein and autoclaved SNL using pepsin and pancreatin. A nonradioactive histone acetyltransferase (HAT) assay and HAT activity colorimetric assay were used to measure the inhibition of core histone acetylation. The inhibitory effect of lunasin on the phosphorylation of retinoblastoma protein (Rb) was determined by immunoblotting against phospho-Rb. Lunasin isolated from autoclaved SNL inhibited core histone H3 and H4 acetylation, the activities of the HATs, and the phosphorylation of the Rb protein. Lunasin in the crude protein and in the autoclaved crude protein was very stable to pepsin and pancreatin in vitro digestion, while the synthetic pure lunasin was digested at 2 min after the reaction. We conclude that lunasin is a bioactive and bioavailable component in SNL and that consumption of SNL may play an important role in cancer prevention.

The cancer preventive peptide lunasin from wheat inhibits core histone acetylation.

Lunasin is a unique 43-amino acid cancer preventive peptide initially reported in soybean and barley and has been shown to be chemopreventive in mammalian cells and in a skin cancer mouse model against oncogenes and chemical carcinogens. We report here the core histone H3- and H-acetylation inhibitory properties of lunasin from wheat, a new source of the peptide and from the livers of rats fed with lunasin-enriched wheat (LEW) to measure bioavailability. A non-radioactive histone acetyl transferase assay was used to measure inhibition of core histone acetylation. The presence of lunasin in wheat was established by Western blot and identified by liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS). Lunasin isolated from wheat seeds at different stages of development inhibited core histone H3 and H4 acetylation in a dose-dependent manner. Lunasin extracted from liver of rats fed with lunasin-enriched wheat (LEW) also inhibited histone acetylation confirming that the peptide is intact and bioactive. The amounts of lunasin in the developing seeds and in the rat liver correlated extremely well with the extent of inhibition of core histone acetylation.

Inhibition of core histone acetylation by the cancer preventive peptide lunasin.

Lunasin is a unique 43 amino acid soy peptide that has been shown to be chemopreventive in mammalian cells and in a skin cancer mouse model in this work against oncogenes and chemical carcinogens. The observation that lunasin inhibits core histone acetylation led to the proposal of an epigenetic mechanism by which lunasin selectively kills cells that are being transformed by disrupting the dynamics of cellular histone acetylation-deacetylation when the transformation event is triggered by the inactivation of tumor suppressors that function via histone deacetylation. Here is reported for the first time the core histone H3- and H4-acetylation inhibitory properties of lunasin from different Korean soybean varieties used for various food purposes and from tissues of rats fed with lunasin-enriched soy (LES) to measure bioavailability. Lunasin was analyzed by immunostaining and inhibition of core histone acetylation by a non-radioactive histone acetyl transferase assay. Various amounts of lunasin are found in the soybean varieties, which correlated with the extent of inhibition of core histone acetylation. Both soy lunasin and synthetic lunasin inhibit core histone acetylation in a dose-dependent manner. Lunasin in LES is protected from in vitro digestion by pepsin. Lunasin extracted from blood and liver of rats fed with LES is intact and inhibits core histone acetylation.