• Title, Summary, Keyword: chemopreventive

Search Result 473, Processing Time 0.046 seconds

Effect of Lunasin Extracted from Millet (Panicum miliaceum) on the Activity of Histone Acetyltransferases, yGCN5 and p/CAF

  • Park, Jae-Ho;Jeong, Jin-Boo;Lee, Jeong-Rak;Lumen, Ben O. De;Jeong, Hyung-Jin
    • Korean Journal of Plant Resources
    • /
    • v.22 no.3
    • /
    • pp.203-208
    • /
    • 2009
  • Lunasin is a unique 43-amino acid peptide which has shown a chemopreventive in mammalian cells and in a skin cancer mouse model. In search for new sources of lunasin and the role of cereals in cancer prevention, we report here the properties of lunasin purified from millet. Stability of millet lunasin was measured by in vitro digestibility assay using pepsin and pancreatin. Inhibition of HAT (histone acetyltransferase) and nuclear localization in mammalian cells were used to measure lunasin bioactivity as the cancer chemopreventive agent. Lunasin present in millet crude protein was stable to pepsin and pancreatin in in vitro digestion and inhibited the activities of HATs. When added exogenously, lunasin purified from millet internalized in the nuclei of mouse fibroblast cells. On the base of this result, we conclude that lunasin in millet is bioactive and consumption of millet may play an important role on cancer prevention in millet-consuming populations.

Strobilanthes crispus Juice Concentrations and Anticancer Effects on DNA Damage, Apoptosis and Gene Expression in Hepatocellular Carcinoma Cells

  • Hussin, Faridah;Eshkoor, Sima Ataollahi;Rahmat, Asmah;Othman, Fauziah;Akim, Abdah;Eshak, Zolkapli
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.14
    • /
    • pp.6047-6053
    • /
    • 2015
  • Background: Hepatocellular carcinoma is one of the most common cancers worldwide. Its prevalence is increasing in many countries. Plant products can be used to protect against cancer due to natural anticancer and chemopreventive constituents. Strobilanthes crispus is one of plants with potential chemopreventive ability. Objective: This study aimed to evaluate the anticancer effects of Strobilanthes crispus juice on hepatocellular carcinoma cells. Materials and Methods: MTT assays, flow cytometry, comet assays and the reverse transcription-polymerase chain reaction (RT-PCR) were used to determine the effects of juice on DNA damage and cancer cell numbers. Results: This juice induced apoptosis after exposure of the HepG2 cell line for 72 h. High percentages of apoptotic cell death and DNA damage were seen at the juice concentrations above 0.1%. It was found that the juice was not toxic for normal cells. In addition, juice exposure increased the expression level of c-myc gene and reduced the expression level of c-fos and c-erbB2 genes in HepG2 cells. The cytotoxic effects of juice on abnormal cells were in dose dependent. Conclusions: It was concluded that the Strobilanthes crispus juice may have chemopreventive effects on hepatocellular carcinoma cells.

Effect of Luteolin on the Levels of Glycoproteins During Azoxymethane-induced Colon Carcinogenesis in Mice

  • Pandurangan, Ashok Kumar;Dharmalingam, Prakash;Sadagopan, Suresh Kumar Ananda;Ganapasam, Sudhandiran
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.13 no.4
    • /
    • pp.1569-1573
    • /
    • 2012
  • Luteolin (LUT), a bioflavonoid has been used as a chemopreventive agent world-wide against chemically induced cancer. Hence we designed an experiment to assess chemopreventive action of LUT on lipid peroxidation (LPO) and glycoconjugates in azoxymethane (AOM)-induced colon carcinogenesis. Colon cancer was induced by 15 mg/body kg. body weight of AOM and administration of LUT (at the dose of 1.2 mg/kg. body weight) was till end of the study. Analysis of lipid peroxidative end products such as protein carbonyl (PC), malonadehyde (MDA) and conjucated dienes (CD) demonstrated significant increase in in AOM-induced animals with reduction by LUT (p<0.05). Increased levels of glycoconjugates such as hexose, hexosamine, sialic acid, fucose and mucoprotein were analyzed in serum and colon tissues examined histopathologically by periodic acid Schiff's (PAS) staining were also reversed by LUT l(p<0.05). The secondary marker of colon cancer mucin depleted foci (MDF) was assessed in control and experimental group of animals. A characteristic increase of MDF was observed in AOM-induced colon cancer animals. Treatment with LUT decreased the incidence of MDF. These results suggest that LUT alters the expression of glycoconjugates and suppress colon cancer. Hence, we speculate that LUT can be used as a chemopreventive agent to treat colon cancer.

Chemopreventive Potential of Coumarin in 7,12-dimethylbenz[a] anthracene Induced Hamster Buccal Pouch Carcinogenesis

  • Baskaran, Nagarethinam;Manoharan, Shanmugam;Karthikeyan, Sekar;Prabhakar, Murugaraj Manoj
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.13 no.10
    • /
    • pp.5273-5279
    • /
    • 2012
  • The aim of the present study was to investigate the chemopreventive effect of coumarin against 7, 12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis by monitoring tumor incidence and histopathological changes as well as by analyzing the status of biochemical markers (lipid peroxidation, enzymatic and non-enzymatic antioxidants, phase I and phase II detoxification enzymes). Oral squamous cell carcinomas were induced in the buccal pouch of Syrian golden hamsters by painting with 0.5% DMBA in liquid paraffin three times a week for 14 weeks. We noted 100% tumor formation with marked abnormalities in the biomarkers status in hamsters treated with DMBA alone. Oral administration of coumarin at a dose of 100 mg/kg body weight (bw) to DMBA treated hamsters completely prevented the tumor formation as well as restored the staus of biochemical variables. The results of the present study thus suggest that the chemopreventive effect of coumarin is probably due to its anti-lipid peroxidative potential and modulating effect on carcinogen detoxification agents in favor of the excretion of ultimate carcinogenic metabolites of DMBA during DMBA-induced hamster buccal pouch carcinogenesis.

The Chemopreventive Effects of Antioxidant Enzyme (항산화효소의 암 예방 효과 및 발암 억제 기전)

  • Jung Hwa-Jin;Choi Yoon-Joo;Won Chang-Won;Seo Young-Rok
    • Environmental Mutagens and Carcinogens
    • /
    • v.26 no.2
    • /
    • pp.45-47
    • /
    • 2006
  • The reactive oxygen species (ROS) caused the damage of macro molecules, many degenerative disease and cancer, which was produced in process of the aerotropic metabolic pathway as well as in response to the various genotoxic stresses. Recently, redox systems including the number of antioxidant proteins such as catalase, glutathione peroxidase, heam-containing peroxidase, peroxiredoxin and superoxide dismutase (SOD) has been reported to have chemopreventive effects. Antioxidant proteins has been known to have the activity directly removing ROS and affecting the protein-protein interaction and cell signaling to induce the cellular responses. We need to understand the mechanism of antioxidants prevent DNA damage from oxidative stresses for researching the cancer prevention and providing the development of cancer therapeutic drug.

  • PDF

SUPPRESSION OF PHORBOL ESTER-INDUCED EXPRESSION OF CYCLLOOXYGENASE-2 AND INDUCIBLE NITRIC OXIDE SYNTHASE BY SELCTED CHEMOPREVENTIVE PHYTOCHEMICALS VIA DOWN-REGULATION OF NF-$\textsc{k}$B

  • Surh, Young-Joon
    • Proceedings of the Korean Society of Toxicology Conference
    • /
    • /
    • pp.88.2-98
    • /
    • 2002
  • A wide arry of naturally occurring substances particularly those present in dietary and medicinal plants, have been reported to possess substantial cancer chemopreventive properties. Certain phytochemicals retain strong antioxidative and anti-inflammatory properties which appear to contribute to their chemopreventive or chemoprotective activities. Inducible cyclooxygenase(COX-2) and nitric oxide synthase (iNOS) are important enzymes that mediate inflammatory processes. There is some evidence that expression of both COX-2 and iNOS is co-regulated by the eukaryotic transcription factor NF-$textsc{k}$B. Increased expression of COX-2 and/or iNOS has been associated with pathophysiology of certain types of human cancers as well as inflammatory diseases. Since inflammation is closely linked to tumor promotion, substances with potent anti-inflammatory activies are anticipated to exert chemopreventive effects on carcinogenesis, particularly in the promotion stage. An example is curcumin, a yellow pigment of turmeric (Curcuma longa L., Zingiberaceae), that strongly occurring diaryl heptanoids structurally related to curcumin have substantial anti-tumor promotional activities in two-stage mouse skin carcinogenesis. Thus, yakuchinone A [1-(4'-hydroxy-3'-methoxyphenyl)-7-phenyl-3heptanone] and yakuchinone B [1-(4'-hydroxy-3'methoxyphenyl)-7-phenylhept-1-en-3-one] present in Alpinia oxyphylla Miquel (Zingiberacease) attenuate phorbol ester-induced inflammation and papilloma formation in female ICR mice. These diarylheptanoids also suppressed phorbol ester-induced activation of epdermal ornithine decarboxylase and its mRNA expression when applied onto shaven backs of mice. Yakuchinone A and B as well as curcumin inhibited phorbol ester-induced expression of COX-2 and iNOS and their mRNA in mouse skin via inactivation of NF-$textsc{k}$B. Capsaicin, a major pungent ingredient of red pepper also attenuated phorbol ester-induced NF-$textsc{k}$B activation. Similar suppression of COX-2 and iNOS and down-regulation of NF-$textsc{k}$B activation for its DNA binding were observed with the ginsenosied Rg3 and the ethanol extract of Artemisia asiatica. We have also found that certain anti-inflammatory phytochemicals exert inhibitory effects on phorbol ester-induced COX-2 expression and NF-$textsc{k}$B activation in immortalized human breast epithelial (MCF-10A) cells in culture. One of the plausible mechanisms undelying inhibition by aforementioned phytochemicals of phorbol ester-induced NF-$textsc{k}$B activation involves interference with degragation of the inhibitory unit, I$textsc{k}$Ba, which blocks subsequent nuclear translocation of the functionally active p65 subunit of NF-$textsc{k}$B. the activation of epidermal NF-$textsc{k}$B by phorbol ester and subsequent induction of COX-2 hence appear to play an important role in intracellular signaling pathwasy leading to tumor promotion and targeted inhibition of NF-$textsc{k}$B may provide a new promising cancer chemopreventive strategy.

  • PDF

Differential Expression and Stability of Endogenous Nuclear Factor E2-related Factor 2 (Nrf2) by Natural Chemopreventive Compounds in HepG2 Human Hepatoma Cells

  • Jeong, Woo-Sik;Keum, Young-Sam;Chen, Chi;Jain, Mohit R.;Shen, Guoxiang;Kim, Jung-Hwan;Li, Wenge;Kong, Ah-Ng Tony
    • BMB Reports
    • /
    • v.38 no.2
    • /
    • pp.167-176
    • /
    • 2005
  • Nuclear factor-E2-related factor 2 (Nrf2) is known as a key regulator of ARE-mediated gene expression and the induction of Phase II detoxifying enzymes and antioxidant enzymes, which is also a common property of many chemopreventive agents. In the present study, we investigated the regulatory role of different chemopreventive agents including sulforaphane (SUL), allyl isothiocyanate (AITC), indole-3-carbinol (I3C), and parthenolide (PTL), in the expression and degradation of Nrf2 and the induction of the antioxidant enzyme HO-1. SUL strongly induced Nrf2 protein expression and ARE-mediated transcription activation, retarded degradation of Nrf2 through inhibiting Keap1, and thereby activating the transcriptional expression of HO-1. AITC was also a potent inducer of Nrf2 protein expression, ARE-reporter gene and HO-1 but had little effect on delaying the degradation of Nrf2 protein. Although PTL and I3C could induce ARE reporter gene expression and Nrf2 to some extent, they were not as potent as SUL and AITC. However, PTL dramatically induced the HO-1 expression, which was comparable to SUL, while I3C had no effect. In addition, when treated with SUL and PTL, inhibition of proteasome by MG132 did not cause additional accumulation of Nrf2, suggesting the involvement of other degradation mechanism(s) in the presence of these compounds such as SUL and PTL. In summary, the results of our current study indicated that different chemopreventive compounds have different regulatory properties on the accumulation and degradation of Nrf2 as well as the induction of cellular antioxidant enzyme HO-1.