• 제목/요약/키워드: nuclear factor E2-related factor 2 (Nrf2)

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Oral administration of hydrolyzed red ginseng extract improves learning and memory capability of scopolamine-treated C57BL/6J mice via upregulation of Nrf2-mediated antioxidant mechanism

  • Ju, Sunghee;Seo, Ji Yeon;Lee, Seung Kwon;Oh, Jisun;Kim, Jong-Sang
    • Journal of Ginseng Research
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    • v.45 no.1
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    • pp.108-118
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    • 2021
  • Background: Korean ginseng (Panax ginseng Meyer) contains a variety of ginsenosides that can be metabolized to a biologically active substance, compound K. Previous research showed that compound K could be enriched in the red ginseng extract (RGE) after hydrolysis by pectinase. The current study investigated whether the enzymatically hydrolyzed red ginseng extract (HRGE) containing a notable level of compound K has cognitive improving and neuroprotective effects. Methods: A scopolamine-induced hypomnesic mouse model was subjected to behavioral tasks, such as the Y-maze, passive avoidance, and the Morris water maze tests. After sacrificing the mice, the brains were collected, histologically examined (hematoxylin and eosin staining), and the expressions of antioxidant proteins analyzed by western blot. Results: Behavioral assessment indicated that the oral administration of HRGE at a dosage of 300 mg/kg body weight reversed scopolamine-induced learning and memory deficits. Histological examination demonstrated that the hippocampal damage observed in scopolamine-treated mouse brains was reduced by HRGE administration. In addition, HRGE administration increased the expression of nuclear-factor-E2-related factor 2 and its downstream antioxidant enzymes NAD(P)H:quinone oxidoreductase and heme oxygenase-1 in hippocampal tissue homogenates. An in vitro assay using HT22 mouse hippocampal neuronal cells demonstrated that HRGE treatment attenuated glutamate-induced cytotoxicity by decreasing the intracellular levels of reactive oxygen species. Conclusion: These findings suggest that HRGE administration can effectively alleviate hippocampus-mediated cognitive impairment, possibly through cytoprotective mechanisms, preventing oxidative-stress-induced neuronal cell death via the upregulation of phase 2 antioxidant molecules.

Anti-inflammatory Activity of Extracts of Hovenia dulcis on Lipopolysaccharides-stimulated RAW264.7 Cells (LPS로 유도된 RAW264.7 대식세포에 대한 헛개나무(Hovenia dulcis) 추출물의 항염증 효과)

  • Woo, Hyun Sim;Lee, Sun Min;Heo, Jeong Doo;Lee, Min-Sung;Kim, Yeong-Su;Kim, Dae Wook
    • Korean Journal of Plant Resources
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    • v.31 no.5
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    • pp.466-477
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    • 2018
  • In this study, the anti-inflammatory activities of the extracts of different parts of Hovenia dulcis such as leaves, stems, and roots were investigated. Among them, the roots extract (RE) showed the most potent suppressive effect against pro-inflammatory mediators in LPS-stimulated mouse macrophage cells. RE induced dose-dependent reduction of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and concomitantly reduced the production of NO and $PGE_2$. Additionally, pre-treatment with RE significantly suppressed the production of inflammatory cytokines, such as tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), interleukin $(IL)-1{\beta}$, and IL-6, as well as mRNA levels. Moreover, phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear translocation of nuclear factor-kappa B (NF-kB) were also strongly attenuated by RE in RAW264.7 cell. Furthermore, RE induced HO-1 expression through nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) and increase HO-1 activity in RAW264.7 macrophages. Therefore, these results indicate that RE strongly inhibits LPS-induced inflammatory responses by blocking NF-kB activation, inhibiting MAPKs phosphorylation, and enhancing HO-1 expression in macrophages, suggesting that RE of H. dulicis and a major component, 27-O-protocatechuoylbetulinic acid could be applied as a valuable natural anti-inflammatory material.

Anti-inflammatory Effect of the Cirsium japonicum var. ussuriense 70% Ethanolic Extract in RAW264.7 Cells by Heme oxygenase-1 Expression (엉겅퀴 70% 에탄올 추출물의 RAW264.7 세포에서 Heme oxygenase-1 발현을 통한 항염증 효과)

  • Lee, Dong-Sung;Kim, Kyoung-Su;Li, Bin;Choi, Hyun-Gyu;Keo, Samell;Jun, Ki-Young;Park, Jun-Hyeong;Kim, Youn-Chul
    • Korean Journal of Pharmacognosy
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    • v.43 no.1
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    • pp.39-45
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    • 2012
  • Cirsium japonicum var. ussuriense has long been used in herbal medicine for the treatment of arthritis, dyspepsia, and bleeding in Korea. In the present study, we investigated anti-inflammatory effects of C. japonicum var. ussuriense against lipopolysaccharide(LPS)-induced activation in RAW264.7 cells by the expression of heme oxygenase (HO)-1. The 70% EtOH extract of the aerial parts of C. japonicum var. ussuriense (CJE), showed the potent anti-inflammatory effects on LPS-induced inflammation in RAW264.7 cells. The anti-inflammatory effect of CJE was demonstrated by the suppression of pro-inflammatory mediators, including pro-inflammatory enzymes (inducible nitric oxide synthase and cyclooxygenase-2). Furthermore CJE induced HO-1 expression through nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) and increased HO activity in RAW264.7 macrophages. The effects of CJE on LPS-induced NO and $PGE_2$ productions were partially reversed by an HO-1 inhibitor, tin protoporphyrin (SnPP). Therefore, it is suggested that CJE-induced HO-1 expression plays a role of the resulting anti-inflammatory effects in macrophages. These results suggest that CJE may be a promising candidate for the treatment of inflammatory diseases.