scholarly journals Chemical Constituents with GNMT-Promoter-Enhancing and NRF2-Reduction Activities from Taiwan Agarwood Excoecaria formosana

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1746
Author(s):  
Ho-Cheng Wu ◽  
Ming-Jen Cheng ◽  
Chia-Hung Yen ◽  
Yi-Ming Arthur Chen ◽  
Yi-Siao Chen ◽  
...  

Hepatocellular carcinoma (HCC) is considered to be a silent killer, and was the fourth leading global cause of cancer deaths in 2018. For now, sorafenib is the only approved drug for advanced HCC treatment. The introduction of additional chemopreventive agents and/or adjuvant therapies may be helpful for the treatment of HCC. After screening 3000 methanolic extracts from the Formosan plant extract bank, Excoecaria formosana showed glycine N-methyltransferase (GNMT)-promoter-enhancing and nuclear factor erythroid 2-related factor 2 (NRF2)-suppressing activities. Further, the investigation of the whole plant of E. formosana led to the isolation of a new steroid, 7α-hydroperoxysitosterol-3-O-β-d-(6-O-palmitoyl)glucopyranoside (1); two new coumarinolignans, excoecoumarin A (2) and excoecoumarin B (3); a new diterpene, excoeterpenol A (4); and 40 known compounds (5–44). Among them, Compounds 38 and 40–44 at a 100 μM concentration showed a 2.97 ± 0.27-, 3.17 ± 1.03-, 2.73 ± 0.23-, 2.63 ± 0.14-, 6.57 ± 0.13-, and 2.62 ± 0.05-fold increase in GNMT promoter activity, respectively. In addition, Compounds 40 and 43 could reduce NRF2 activity, a transcription factor associated with drug resistance, in Huh7 cells with relative activity of 33.1 ± 0.2% and 45.2 ± 2.5%. These results provided the basis for the utilization of Taiwan agarwood for the development of anti-HCC agents.

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 401-401
Author(s):  
Dongyup Hahn ◽  
Taeho Lee ◽  
Sangkyu Lee ◽  
Jong-Sup Bae ◽  
MinKyun Na ◽  
...  

Abstract Objectives Maca (Lepidium meyenii) is a biennial herbaceous plant of family Brassicaceae with various bioactivities such as reproductive health enhancement, antifatigue, antioxidation, neuroprotection, anticancer, hepatoprotection, and immunomodulation. But studies on molecular mechanisms beyond the phenomenal physiology are rare because the putative bioactive chemical constituents, macamides, a series of unique N-benzylamides with long-chain fatty acids are difficult to isolate from the natural maca specimen. In this study, ten macamides were chemically synthesized to investigate biological mechanisms underlying the various bioactivities. Methods Macamides were synthesized from benzylamides and commercially available fatty acids adding 1,1'-carbonyl diimidazole. Nrf2 activation of macamides were measured using U2OS cells in CP0. Quantitative analysis of bioactive macamides were performed using LC-MS/MS system and synthesized standard macamides. The difference in composition of macamides among three cultivars, yellow, red and black macas was also examined. Results Three of macamides exhibited moderate nuclear factor erythroid 2-related factor 2 (Nrf2) activation was observed from cell-based assay (EC50 7.3–16.5 μM), which might account for some of the known bioactivities of maca. Quantitative analysis of macamide compositions in maca specimen using LC-MS/MS was followed, which revealed the macamides with Nrf2 activation activity consist the majority among macamides contained in maca. Conclusions Among the bioactivities that have known as the beneficial effects of maca, bioactivities related to antioxidation might be accounted for the Nrf2 activation of macamides contained in maca. Funding Sources This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (2019R1F1A1051041).


2020 ◽  
Vol 19 (2) ◽  
pp. 133-138
Author(s):  
Wenyu Chen ◽  
Hui He

Trilobatin is a natural plant-derived glycosylated flavonoid that has been shown to exhibit multiple beneficial pharmacologic activities including protection of heart against H/R-induced cardiomyocyte injury. However, the molecular mechanisms underlying protection from H/R-induced cardiomyocyte injury remain unknown. Using H9C2 cells as a model, we examined the effect of trilobatin on H/R-induced cellular injury, apoptosis, and generation of reactive oxygen species. The results showed that trilobatin protected H9C2 cells not only from cell death and apoptosis, but also counteracted H/R-induced changes in malondialdehyde, superoxide dismutase, glutathione, and glutathione peroxidase. The evaluation of the mechanism underlying the effect of trilobatin on protection from H/R-induced cellular injury suggested changes in the regulation of nuclear factor erythroid 2-related factor 2/heme oxygenase-1 pathway.


2020 ◽  
Vol 18 (3) ◽  
pp. 260-265
Author(s):  
Xu Lin ◽  
Zheng Xiaojun ◽  
Lv Heng ◽  
Mo Yipeng ◽  
Tong Hong

The purpose of this study was to evaluate the protective effect of swertiamarin on heart failure. To this end, a rat model of heart failure was established via left coronary artery ligation. Infarct size of heart tissues was determined using triphenyl tetrazolium chloride staining. Echocardiography was performed to evaluate cardiac function by the determination of ejection fraction, left ventricular internal dimension in diastole and left ventricular internal dimension in systole. The effect of swertiamarin on oxidative stress was evaluated via enzyme-linked immunosorbent assay. The mechanism was evaluated using western blot. Administration of swertiamarin reduced the infarct size of heart tissues in rat models with heart failure. Moreover, swertiamarin treatment ameliorated the cardiac function, increased ejection fraction and fractional shortening, decreased left ventricular internal dimension in diastole and left ventricular internal dimension in systole. Swertiamarin improved oxidative stress with reduced malondialdehyde, while increased superoxide dismutase, glutathione, and GSH peroxidase. Furthermore, nuclear-factor erythroid 2-related factor 2, heme oxygenase and NAD(P)H dehydrogenase (quinone 1) were elevated by swertiamarin treatment in heart tissues of rat model with heart failure. Swertiamarin alleviated heart failure through suppression of oxidative stress response via nuclear-factor erythroid 2-related factor 2/heme oxygenase-1 pathway providing a novel therapeutic strategy for heart failure.


2020 ◽  
Vol 17 ◽  
Author(s):  
Balogun Olaoye Solomon ◽  
Ajayi Olukayode Solomon ◽  
Owolabi Temitayo Abidemi ◽  
Oladimeji Abdulkarbir Oladele ◽  
Liu Zhiqiang

: Cissus aralioides is a medicinal plant used in sub-Saharan Africa for treatment of infectious diseases; however the chemical constituents of the plant have not been investigated. Thus, in this study, attempt was made at identifying predominant phytochemical constituents of the plant through chromatographic purification and silylation of the plant extract, and subsequent characterization using spectroscopic and GC-MS techniques. The minimum inhibitory concentration (MICs) for the antibacterial activities of the plant extract, chromatographic fractions and isolated compounds were also examined. Chromatographic purification of the ethyl acetate fraction from the whole plant afforded three compounds: β-sitosterol (1), stigmasterol (2) and friedelin (3). The phytosterols (1 and 2) were obtained together as a mixture. The GC-MS analysis of silylated extract indicated alcohols, fatty acids and sugars as predominant classes, with composition of 24.62, 36.90 and 26.52% respectively. Results of MICs indicated that friedelin and other chromatographic fractions had values (0.0626-1.0 mg/mL) comparable with the standard antibiotics used. Characterization of natural products from C. aralioides is being reported for the first time in this study.


2000 ◽  
Vol 279 (3) ◽  
pp. H939-H945 ◽  
Author(s):  
Shareef Mustapha ◽  
Alla Kirshner ◽  
Danielle De Moissac ◽  
Lorrie A. Kirshenbaum

Nuclear factor-κB (NF-κB) is a ubiquitously expressed cellular factor regulated by the cytoplasmic factor inhibitor protein κBα (IκBα). Activation of NF-κB by cytokines, including tumor necrosis factor-α (TNF-α), requires the phosphorylation and degradation of IκBα. An anti-apoptotic role for NF-κB has recently been suggested. In the present study, we ascertained whether death-promoting signals and apoptosis mediated by TNF-α are suppressed by NF-κB in postnatal ventricular myocytes. Stimulation of myocytes with TNF-α resulted in a 12.1-fold increase ( P < 0.01) in NF-κB-dependent gene transcription and DNA binding compared with controls. This was accompanied by a corresponding increase in the NF-κB target protein A20 as determined by Western blot analysis. Vital staining revealed that TNF-α was not cytotoxic to myocytes and did not provoke apoptosis. Adenovirus-mediated delivery of a nonphosphorylatable form of IκBα to inactivate NF-κB prevented TNF-α-stimulated NF-κB-dependent gene transcription and nuclear NF-κB DNA binding. Importantly, myocytes stimulated with TNF-α and defective for NF-κB activation resulted in a 2.2-fold increase ( P < 0.001) in apoptosis. To our knowledge, the data provide the first indication that a functional NF-κB signaling pathway is crucial for suppressing death-promoting signals mediated by TNF-α in ventricular myocytes.


2021 ◽  
Vol 22 (15) ◽  
pp. 8223
Author(s):  
Violetta Krajka-Kuźniak ◽  
Wanda Baer-Dubowska

Nrf2 (nuclear factor erythroid 2-related factor 2) and NF-κB (nuclear factor–kappa B) signaling pathways play a central role in suppressing or inducing inflammation and angiogenesis processes. Therefore, they are involved in many steps of carcinogenesis through cooperation with multiple signaling molecules and pathways. Targeting both transcription factors simultaneously may be considered an equally important strategy for cancer chemoprevention and therapy. Several hundreds of phytochemicals, mainly edible plant and vegetable components, were shown to activate Nrf2 and mediate antioxidant response. A similar number of phytochemicals was revealed to affect NF-κB. While activation of Nrf2 and inhibition of NF-κB may protect normal cells against cancer initiation and promotion, enhanced expression and activation in cancer cells may lead to resistance to conventional chemo- or radiotherapy. Most phytochemicals, through different mechanisms, activate Nrf2, but others, such as luteolin, can act as inhibitors of both Nrf2 and NF-κB. Despite many experimental data confirming the above mechanisms currently, limited evidence exists demonstrating such activity in humans. Combinations of phytochemicals resembling that in a natural food matrix but allowing higher concentrations may improve their modulating effect on Nrf2 and NF-κB and ultimately cancer prevention and therapy. This review presents the current knowledge on the effect of selected phytochemicals and their combinations on Nrf2 and NF-κB activities in the above context.


Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 25
Author(s):  
Lara Macchioni ◽  
Davide Chiasserini ◽  
Letizia Mezzasoma ◽  
Magdalena Davidescu ◽  
Pier Luigi Orvietani ◽  
...  

Age-related retinal degenerations, including age-related macular degeneration (AMD), are caused by the loss of retinal pigmented epithelial (RPE) cells and photoreceptors. The pathogenesis of AMD, deeply linked to the aging process, also involves oxidative stress and inflammatory responses. However, the molecular mechanisms contributing to the shift from healthy aging to AMD are still poorly understood. Since RPE cells in the retina are chronically exposed to a pro-oxidant microenvironment throughout life, we simulated in vivo conditions by growing ARPE-19 cells in the presence of 10 μM H2O2 for several passages. This long-term oxidative insult induced senescence in ARPE-19 cells without affecting cell proliferation. Global proteomic analysis revealed a dysregulated expression in proteins involved in antioxidant response, mitochondrial homeostasis, and extracellular matrix organization. The analyses of mitochondrial functionality showed increased mitochondrial biogenesis and ATP generation and improved response to oxidative stress. The latter, however, was linked to nuclear factor-κB (NF-κB) rather than nuclear factor erythroid 2–related factor 2 (Nrf2) activation. NF-κB hyperactivation also resulted in increased pro-inflammatory cytokines expression and inflammasome activation. Moreover, in response to additional pro-inflammatory insults, senescent ARPE-19 cells underwent an exaggerated inflammatory reaction. Our results indicate senescence as an important link between chronic oxidative insult and detrimental chronic inflammation, with possible future repercussions for therapeutic interventions.


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