A polysaccharide extracted from rice bran fermented with Lentinus edodes enhances natural killer cell activity and exhibits anticancer effects.

Erom R&D Center, Erom Co., Ltd., Gyeonggi-do, Republic of Korea.
Journal of Medicinal Food (Impact Factor: 1.64). 04/2007; 10(1):25-31. DOI: 10.1089/jmf.2006.116
Source: PubMed

ABSTRACT The objective of this study was to investigate the activation of natural killer (NK) cells and anticancer effects of exo-biopolymer from rice bran cultured with Lentinus edodes [rice bran exo-biopolymer (RBEP)]. Oral administration of RBEP induced the activation of NK cells in a dose-dependent manner. RBEP also prolonged the life spans of mice transplanted with Sarcoma-180 cells and inhibited growing Sarcoma-180 cells in intraperitoneum. Solid tumor growth was also suppressed by oral administration of RBEP in C57/Bl6 mice transplanted with B16/Bl6 melanoma. Intraperitoneal injection of RBEP was more effective than oral administration at the same dosage in mice with transplanted tumor cells. According to this result, when RBEP directly contacts immune cells, the anticancer activity is higher than by indirectly inducing an immune response through oral administration. Therefore, we suggest that the administration of RBEP may be effective for preventing and/or treating cancer through NK cell activation. However, further studies are needed to elucidate the possible mechanisms of the anticancer activity and to investigate the other beneficial effects of RBEP for the development of a new biological response modifier.

1 Bookmark
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this study, the effects of water extracts of fermented rice bran (FRBE) on immediate-type allergic reactions in vitro (RBL-2H3 cell line) and in vivo [ovalbumin (OVA) sensitized mice model] were investigated. FRBE inhibited β-hexosaminidase release from RBL-2H3 cells activated by anti-dinitrophenyl (DNP) IgE while FRBE pretreatment profoundly inhibited the systemic allergic reaction induced by compound 48/80. Moreover, FRBE had a significant inhibitory effect on the mRNA expression of anti-DNP IgE-induced tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-4, IL-6, and IL-10, all of which mediate inflammatory reactions triggered by allergic reaction. To determine the mRNA levels of cytokines in an OVA-sensitized mice model after FRBE treatment, spleen cells were harvested with several concentrations of FRBE. The FRBE-treated group showed decreased levels of TNF-α, IFN-γ, IL-6, and IL-10. These results suggest that FRBE suppressed allergic and inflammatory reactions through inhibition of degranulation, histamine release, and pro-inflammatory cytokine production from mast cells. Keywordswater extract of fermented rice bran–allergic reaction–RBL-2H3 cell–β-hexosaminidase–pro-inflammatory chemotactic cytokine
    Food science and biotechnology 19(6):1573-1578. · 0.70 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Mushroom extracts are increasingly sold as dietary supplements because of several of their properties, including the enhancement of immune function and antitumor activity. We hypothesized that soluble polar substances present in mushroom extracts may show antioxidant and anticancer properties. This report shows that Brazilian aqueous extracts of Lentinula edodes and Pleurotus sajor-caju exert inhibitory activity against the proliferation of the human tumor cell lines laryngeal carcinoma (Hep-2) and cervical adenocarcinoma (HeLa). Cell viability was determined after using 3 different temperatures (4°C, 22°C, and 50°C) for mushroom extraction. Biochemical assays carried out in parallel indicated higher amounts of polyphenols in the L edodes extracts at all extraction temperatures investigated. The scavenging ability of the 2,2-diphenyl-1-picrylhydrazyl radical showed higher activity for L edodes extracts. Superoxide dismutase-like activity showed no statistically significant difference among the groups for the 2 tested extracts, and catalase-like activity was increased with the L edodes extracts at 4°C. The results for the cytotoxic activity from P sajor-caju extracts at 22°C revealed the half maximal inhibitory concentration values of 0.64% ± 0.02% for Hep-2 and 0.25% ± 0.02% for HeLa. A higher cytotoxic activity was found for the L edodes extract at 22°C, with half maximal inhibitory concentration values of 0.78% ± 0.02% for Hep-2 and 0.57% ± 0.01% for HeLa. Substantial morphological modifications in cells were confirmed by Giemsa staining after treatment with either extract, suggesting inhibition of proliferation and induction of apoptosis with increasing extract concentrations. These results indicate that the aqueous extracts of Brazilian L edodes and P sajor-caju mushrooms are potential sources of antioxidant and anticancer compounds. However, further investigations are needed to exploit their valuable therapeutic uses and to elucidate their modes of action.
    Nutrition research 01/2013; 33(1):76-84. · 2.59 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this study, we investigated whether fermented rice bran (FRB) can ameliorate the oxidative stress induced by high glucose and hydrogen peroxide (H(2)O(2)) in 3T3-L1 adipocytes by analyzing reactive oxygen species (ROS), oil red O staining, as well as the expression of mRNAs related to glucose homeostasis and adipogenesis. It was first confirmed that rice bran fermented by Issatchenkia orientalis MFST1 extract increased free phenolic content compared to non-fermented rice bran. The FRB extract strongly inhibited ROS generation and upregulated the expression of PPAR-γ and adiponectin. Moreover, FRB upregulated GLUT4 related to glucose transportation and insulin sensitivity. Taken together, FRB extract ameliorated oxidative stress-induced insulin resistance by neutralizing free radicals and upregulating adiponectin in adipocytes. Our results provide information toward understanding the beneficial effects of FRB on oxidative stress.
    Plant Foods for Human Nutrition 09/2011; 66(3):285-90. · 2.36 Impact Factor