Hyung Jin Jeong

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.

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.

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.

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.

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.

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.

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

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.

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 (PGE2), 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 PGE2 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, PGE2, iNOS, and COX-2 in RAW264.7 cells. These effects are mediated by suppression of NF-κB and MAPK activation and histone acetylation.

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.