2-Methoxy-7-Acetonyljuglone Isolated from Reynoutria japonica Increases the Activity of Nuclear Factor Erythroid 2-Related Factor-2 through Inhibition of Ubiquitin Degradation in HeLa Cells

Alginate Oligosaccharides Protect Gastric Epithelial Cells against Oxidative Stress Damage through Induction of the Nrf2 Pathway

Gastric diseases represent a significant global public health challenge, characterized by molecular dysregulation in redox homeostasis and heightened oxidative stress. Although prior preclinical studies have demonstrated the cytoprotective antioxidant effects of alginate oligosaccharides (AOSs) through the Nrf2 pathway, whether such mechanisms apply to gastric diseases remains unclear. In this study, we used the GES-1 gastric cell line exposed to hydrogen peroxide (H2O2) as a damage model to investigate the impact of AOS on cell viability and its associated mechanisms. Our results revealed that pre-incubation with AOS for either 4 h or 24 h significantly improved the viability of GES-1 cells exposed to H2O2. In addition, AOS reduced the intracellular ROS levels, activating the Nrf2 signaling pathway, with increased Nrf2 protein and mRNA expression and a significant upregulation of the target genes HO-1 and NQO1. The activation of Nrf2 was correlated with decreased Keap1 protein expression and an increased level of the autophagy protein p62/SQSTM1, suggesting the activation of Nrf2 through a noncanonical pathway. This study suggests that AOS is a potential treatment for protecting gastric epithelial cells from oxidative stress by activating the p62/SQSTM1-Keap1-Nrf2 axis and laying the foundation for future investigations about its specific therapeutic mechanisms.

Screening and Evaluation of Dermo-Cosmetic Activities of the Invasive Plant Species Polygonum cuspidatum

Polygonum cuspidatum (P. cuspidatum) is among the world's most problematic invasive plant species with negative ecological, socio-economic and security consequences. Management operations in areas invaded systematically generate a large quantity of plant waste, most often without outlets. Using this plant material could constitute a new alternative treatment for sustainable management. P. cuspidatum is well known to have numerous biological properties, containing notably stilbenes, quinones, flavonoids and phenolic acids. The present work proposes a reliable strategy using powerful techniques for the screening and the evaluation of the dermo-cosmetic potential of its aerial parts (AP) and root parts (RP). To the best of our knowledge, only antioxidant and anti-tyrosinase activities were previously evaluated on P. cuspidatum among the targets studied (superoxide dismutase, hyaluronidase, elastase, collagenase and tyrosinase). The results revealed strong antioxidant and anti-collagenase activities, moderate anti-hyaluronidase activity, while weak anti-elastase and anti-tyrosinase activities were observed for ethanolic extracts. Different standards selected and screened on the same targets made it possible to correlate the observed residual activities of produced extracts of P. cuspidatum from Savoie Mont Blanc and their chemical compositions. A structure-activity study was thus conducted on main molecular families, widely represented in the genus Polygonum.

Antibacterial and Antibiofilm Activity of Juglone Derivatives against Enterococcus faecalis: An In Silico and In Vitro Approach

Enterococcus faecalis is a Gram-positive bacterium that is normally found in the gastrointestinal tract of humans and animals. E. faecalis is an opportunistic pathogen that causes a number of invasive and noninvasive infections. The emergence of multidrug resistance and biofilm formation by the bacterium have rendered the treatment of E. faecalis infections very difficult. Due its high rate of resistance and biofilm formation, there are very few options of treatment. Therefore, the current study was designed to evaluate the antibacterial and biofilm activities of juglone derivatives such as 2-methoxy-6-acetyl-7-methyljuglone and 2-ethoxy-6-acetyl-7-methyljuglone against multidrug-resistant (MDR) and biofilm-producing strains of E. faecalis. Agar well diffusion and broth microdilution methods were used to determine the antibacterial activities. Biofilm attachment and preformed biofilm inhibition were determined using crystal violet staining assay. Both juglone derivatives displayed promising antibacterial and antibiofilm activities against E. faecalis. Among these compounds, 2-ethoxy-6-acetyl-7-methyljuglone possessed better inhibitory activity with minimum inhibitory concentration (MIC) of $9.7\pm 3\mu \text{M}$ as compared to 2-methoxy-6-acetyl-7-methyljuglone (MIC, $19.5\pm 2\mu \text{M}$ ). Additionally, 2-ethoxy-6-acetyl-7-methyljuglone also showed stronger antibiofilm activity than 2-methoxy-6-acetyl-7-methyljuglone. Furthermore, both the ligand molecules were docked into the binding site of the enterococcal surface protein, and the results revealed that both the molecules are actively binding in the target site. Based on these findings, juglone derivatives may be considered useful for the treatment of E. faecalis infections; however, further studies are required to elucidate the mechanism of action.

Camellia japonica Root Extract Increases Antioxidant Genes by Induction of NRF2 in HeLa Cells

Camellia japonica L. (Theaceae) has been used for medicinal and cosmetic purposes in East Asian countries. Most functional components were obtained from the upper parts of the tree, such as leaves, flowers, or seeds. Here, we report a functional effect of the 80% methanolic extract of C. japonica root (CJRE) on antioxidative stress in HeLa cells. The nuclear factor erythroid-derived 2-related factor 2 (NRF2) is a key transcription factor that triggers the induction of oxidative stress-relating genes and drug detoxification. As result, CJRE showed a strong anti-radical scavenging effect in a dose-dependent manner. In addition, the induction of antioxidant response elements (ARE)-luciferase activity was maximized at CJRE 200 µg/mL. Furthermore, CJRE induced the mRNA levels of HO-1 and NQO1 by the nuclear NRF2 accumulation. As a possible mechanism of Nrf2 activation, the phosphorylation of p38 and ERK1/2 signaling might fortify the NRF2 induction as well as its stability. However, the phosphorylation of AKT is rather decreased. Taken together, CJRE may potentiate the antioxidant effects by increasing the NRF2 signaling through MAP kinase signaling and the properties of its radical scavenging activity. Thus, CJRE could apply for other medicinal and cosmetic purposes.

An Overview on Rumex dentatus L.: Its Functions as a Source of Nutrient and Health-Promoting Plant

Rumex dentatus L. (Polygonaceae), also known as toothed dock or Aegean dock, is a medicinal plant with a high culinary value in addition to being used as an ethnomedicinal plant. This review focuses on the botanical, nutritional, phytochemical, and pharmacological activities of R. dentatus, as well as the future prospects for systematic investigations into these areas. R. dentatus has been subjected to scientific evaluation, which has confirmed its traditional uses and demonstrated a wide range of biological and pharmacological potentials, including antioxidant, anticancer, antifungal, antibacterial, anti-inflammatory, and other biological properties. Phytochemical analyses showed the presence of anthraquinones, chromones, flavonoids, and essential oils. As a result of this current review, the medicinal significance of R. dentatus has been confirmed, and future research on its unexplored aspects, such as the identification of pharmacologically active chemical constituents and related mechanisms and safety, may be stimulated, with the goal of developing it into a drug.

Molecular biological mechanism of action in cancer therapies: Juglone and its derivatives, the future of development

Juglone (5 - hydroxy - 1, 4 - naphthalene diketone) is a kind of natural naphthoquinone, present in the roots, leaves, nut-hulls, bark and wood of walnut trees. Recent studies have found that Juglone has special significance in the treatment of cancer, which plays a significant role in the resistance of cancer cell proliferation, induction of cancer cell apoptosis, induction of autophagy, anti-angiogenesis and inhibition of cancer cell migration and invasion, etc. Additionally, its derivatives also play a tumor suppressive effect. In conclusion, Juglone and its derivatives have been identified as effective anticancer drugs. This paper reviews action mechanisms of Juglone and its derivatives in cancer treatment.

Medicarpin Increases Antioxidant Genes by Inducing NRF2 Transcriptional Level in HeLa Cells

The nuclear factor erythroid-derived 2-related factor 2 (NRF2) plays a pivotal role in the regulation of genes involved in oxidative stress and drug detoxification. Therefore, it is important to find NRF2 inducers to protect cells from excessive oxidative damage. Here, we investigated the effect of medicarpin isolated from the root of Robinia pseudoacacia L. on the activity of NRF2 in HeLa cells. Medicarpin significantly induced the antioxidant response elements (ARE)-luciferase activity in a concentration-dependent manner. Furthermore, medicarpin not only induced HO-1, GCLC, and NQO1 mRNA by translocating NRF2 to the nucleus but also induced the mRNA level of NRF2. To verify the NRF2 induction mechanism by medicarpin, ~2 kb of NRF2 promoter-luciferase assay was executed. As a result, medicarpin significantly induced NRF2-luciferase activity. Moreover, medicarpin strongly inhibited the ubiquitin-dependent proteasomal degradation of NRF2. Thus, medicarpin might protect cells by promoting the NRF2 transcriptional activity.

Juglone Suppresses Inflammation and Oxidative Stress in Colitis Mice

Juglone (JUG), a natural product found in walnut trees and other plants, shows potent antioxidant, antimicrobial, and immunoregulatory activities. However, it remains unknown whether JUG can alleviate ulcerative colitis. This study aims to explore the effect of JUG on dextran sulfate sodium (DSS)-induced colitis in mice. The mice were randomly assigned into three groups: the vehicle group, the DSS group, and the JUG group. The experiments lasted for 17 days; during the experiment, all mice received dimethyl sulfoxide (DMSO, 0.03% v/v)-containing water, while the mice in the JUG group received DMSO-containing water supplemented with JUG (0.04 w/v). Colitis was induced by administering DSS (3% w/v) orally for 10 consecutive days. The results showed that the JUG treatment significantly ameliorated body weight loss and disease activity index and improved the survival probability, colon length, and tissue damage. JUG reversed the DSS-induced up-regulation of proinflammatory cytokines, including interleukin (IL)-6, 12, 21, and 23, and tumor necrosis factor-alpha, and anti-inflammatory cytokines, such as IL-10 and transforming growth factor-beta, in the serum of the colitis mice. Additionally, the activation of mitochondrial uncoupling protein 2 and phospho-Nuclear Factor-kappa B p65 and the inhibition of the kelch-like ECH-associated protein 1 and NF-E2-related factor 2 induced by DSS were also reversed under JUG administration. Although the JUG group possessed a similar microbial community structure as the DSS group, JUG enriched potential beneficial microbes such as Lachnospiraceae_NK4A136_group but not pathogens such as Escherichia Shigella, which was dominative in DSS group, at the genus level. In conclusion, our results demonstrated that JUG could be a promising agent for UC prevention to regulate inflammatory cytokines and oxidative stress.

Carbon monoxide exposure activates ULK1 via AMPK phosphorylation in murine embryonic fibroblasts

Carbon monoxide (CO) is endogenously produced upon degradation of heme by heme oxygenases (HOs) and is suggested to act as a gaseous signaling molecule. The expression of HO-1 is triggered by the Nrf2-Keap1 signaling pathway which responds to exogenous stress signals and dietary constituents such as flavonoids and glucosinolates or reactive metabolic intermediates like 4-hydroxynonenal. Endogenous CO affects energy metabolism, regulates the utilization of glucose and addresses CYP450 enzymes. Using the CO releasing molecule-401 (CORM-401), we studied the effect of endogenous CO on ATP synthesis, AMP-signaling and activation of the AMPK pathway in cell culture. Upon exposure of cells to CORM-401, the mitochondrial ATP production rate was significantly decreased (P=0.007) to about 50%, while glycolytic ATP synthesis was unchanged (P=0.489). Total ATP levels were less affected as determined by mass spectrometry. Instead, levels of ADP and AMP were elevated following CORM-401 exposure by about two- (P=0.022) and four-fold (P=0.012) compared to control, respectively. Increased concentrations of AMP activate AMPK which was demonstrated by a 10 to 15-fold increased phosphorylation of Thr172 of the α-subunit of AMPK (P=0.025). A downstream target of AMPK is the kinase ULK1 which triggers autophagic and mitophagic processes. Activation of ULK1 after CO exposure was proven by a 3 to 5-fold elevated phosphorylation of ULK1 at Ser555 (P=0.004). The present data suggest that production of endogenous CO leads to increasing amounts of AMP which mediates AMPK-dependent downstream effects and likely triggers autophagic processes. Since dietary constituents and their metabolites induce the expression of the CO producing enzyme HO-1, CO signaling may also be involved in the cellular response to nutritional factors.

Protective effect of coumarin-pi against t-BHP-induced hepatotoxicity by upregulating antioxidant enzymes via enhanced Nrf2 signaling

Coumarin-pi, a new coumarin derivative isolated from the mushroom Paxillus involutus, has antioxidative activity, but the underlying mechanism against intracellular oxidative stress is still unclear. This study investigated its cytoprotective effects and the antioxidative mechanism in tert-butyl hydroperoxide (t-BHP)-induced HepG2 cells. The results demonstrated that coumarin-pi suppressed t-BHP-stimulated cytotoxicity, cell apoptosis, and generation of reactive oxygen species (ROS). Additionally, coumarin-pi promoted nuclear factor erythroid 2-related factor 2 (Nrf2) expression and upregulated the protein expression of antioxidantenzymes, including heme oxygenase-1 (HO-1), NAD(P)H: quinone oxidase (NQO1), glutamyl cysteine ligase catalytic subunit (GCLC), and glutamate-cysteine ligase regulatory subunit (GCLM). After coumarin-pi treatment, transcriptome sequencing and bioinformatic analysis revealed that 256 genes were differentially expressed; interestingly, only 20 genes were downregulated, and the rest of the genes were upregulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional annotation were used to identify changes in metabolic pathways. Collectively, the results presented in this study indicate that coumarin-pi has a protective effect against t-BHP-induced cellular damage and oxidative stress.