► Ellagic acid treatment suppressed UVA-induced ROS generation and MDA formation. ► Ellagic acid treatment inhibited UVA-induced apoptosis in HaCaT cells. ► The antioxidant potential of ellagic acid ...was correlated with HO-1 expression. ► Ellagic acid-induced HO-1 expression was mediated by up-regulation of Nrf2. ► Nrf2 knockdown diminishes the protective effect of ellagic acid.
UV radiation from the sun is a potent environmental risk factor in the pathogenesis of skin damage. Much of the skin damage caused by ultraviolet A (UVA) irradiation from the sun is associated with oxidative stress. The aim of this study was to investigate the protective role of ellagic acid (25–75μM), a natural antioxidant, against UVA (5–20J/cm2)-induced oxidative stress and apoptosis in human keratinocyte (HaCaT) cells and to reveal the possible mechanisms underlying this protective efficacy. Ellagic acid pre-treatment markedly increased HaCaT cell viability and suppressed UVA-induced ROS generation and MDA formation. Moreover, ellagic acid pre-treatment prevented UVA-induced DNA damage as evaluated by the comet assay. Ellagic acid treatment also significantly inhibited the UVA-induced apoptosis of HaCaT cells, as measured by a reduction of DNA fragmentation, mitochondria dysfunction, ER stress, caspase-3 activation, and Bcl-2/Bax deregulation. Notably, the antioxidant potential of ellagic acid was directly correlated with the increased expression of HO-1 and SOD, which was followed by the downregulation of Keap1 and the augmented nuclear translocation and transcriptional activation of Nrf2 with or without UVA irradiation. Nrf2 knockdown diminished the protective effects of ellagic acid. Therefore, ellagic acid may be useful for the treatment of UVA-induced skin damage.
In recent years much attention has been focused on the pharmaceutical relevance of bioflavonoids, especially hesperidin and its aglycon hesperetin in terms of their antioxidant and anti-inflammatory ...actions. However, the bioactivity of their metabolites, the real molecules in vivo hesperetin glucuronides/sulfates produced after ingestion, has been poorly understood. Thus, the study using an ex vivo approach is aimed to compare the antioxidant and anti-inflammatory activities of hesperidin/hesperetin or hesperetin metabolites derived from hesperetin-administered rat serum. We found that hesperetin metabolites (2.5–20 μM) showed higher antioxidant activity against various oxidative systems, including superoxide anion scavenging, reducing power, and metal chelating effects, than that of hesperidin or hesperetin. The data also showed that pretreatment of hesperetin metabolites (1–10 μM) within the range of physiological concentrations, compared to hesperetin, significantly inhibited nitric oxide (NO) and prostaglandin E2 (PGE2) production, as evidenced by the inhibition of their precursors, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein levels without appreciable cytotoxicity on LPS-activated RAW264.7 macrophages or A7r5 smooth muscle cells. Concomitantly, hesperetin metabolites dose-dependently inhibited LPS-induced intracellular reactive oxygen species (ROS). Furthermore, hesperetin metabolites significantly downregulate LPS-induced nuclear factor-κB (NF-κB) activation followed by the suppression of inhibitor-κB (I-κB) degradation and phosphorylation of c-Jun N-terminal kinase1/2 (JNK1/2) and p38 MAPKs after challenge with LPS. Hesperetin metabolites ex vivo showed potent antioxidant and anti-inflammatory activity in comparison with hesperidin/hesperetin.
Epithelial-to-mesenchymal transition (EMT) is a crucial event involved metastasis of certain tumors. Thus, identifying chemical agents that can block EMT is highly warranted for the development of ...anti-cancer chemoprevention/chemotherapies. In this study, we found that Antrodin C (ADC), a maleimide derivative isolated from Antrodia cinnamomea health food product inhibits TGF-β1-induced EMT and breast cancer cell metastasis in vitro. Pretreatment of MCF-7 cells with ADC significantly blocked TGF-β1-induced phenotypic changes and actin cytoskeleton remodeling. In addition, ADC was able to up-regulate epithelial markers such as E-cadherin and occludin, whereas mesenchymal markers including N-cadherin and vimentin were significantly inhibited, possibly through the modulation of transcriptional regulators Smad/Smad3. ADC blocked TGF-β1-induced migration and invasion of MCF-7 cells through the down-regulation of matrix-metalloproteinases (MMP-2, -9) and urokinase plasminogen activator (uPA). The inhibition of MMPs and uPA activity by ADC was reasoned by suppression of its corresponding transcription factor β-catenin. Taken together, our data suggested that ADC attenuates the TGF-β1-induced EMT, migration and invasion of human breast carcinoma through the suppression of Smad2/3 and β-catenin signaling pathways.
► Toona sinensis leaf extracts exhibits anti-inflammatory potential in vivo. ► NF-κB transgenic mice were subjected to bioluminescence imaging technique. ► Toona sinensis significantly suppressed ...LPS-induced NF-κB activation in vivo. ► Gallic acid also significantly down-regulated NF-κB activation in vivo.
In the present study, we investigated the anti-inflammatory effects of a nutritious vegetable Toona sinensis (leaf extracts, TS) and its major bioactive compound gallic acid (GA) by analysing LPS-induced NF-κB activation in transgenic mice, using bioluminescence imaging. Mice were challenged intraperitoneally with LPS (1mg/kg) and treated orally with TS or GA (100 or 5mg/kg, respectively). In vivo and ex vivo imaging showed that LPS increased NF-κB luminescence in the abdominal region, which was significantly inhibited by TS or GA. Immunohistochemical and ELISA analyses confirmed that TS and GA inhibited LPS-induced NF-κB, interleukin-1β, and tumour necrosis factor-α expression. Microarray analysis revealed that biological pathways associated with metabolism and the immune responses were affected by TS or GA. Particularly, LPS-induced thioredoxin-like 4B (TXNL4B) 2 expression in the small intestine, and TXNL4B, iNOS, and COX-2 expression in RAW 264.7 cells were significantly inhibited by TS or GA. Thus, the anti-inflammatory potential of TS was mediated by the downregulation of NF-κB pathway.
Despite the remarkable development of highly effective vaccines, including mRNA-based vaccines, within a limited timeframe, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory ...syndrome coronavirus 2 (SARS-CoV-2) is not been entirely eradicated. Thus, it is crucial to identify new effective anti-3CLPro compounds, pivotal for the replication of SARS-CoV-2. Here, we identified an antcin-B phytosterol-like compound from Taiwanofungus camphoratus that targets 3CLPro activity. MTT assay and ADMET prediction are employed for assessing potential cytotoxicity. Computational molecular modeling was used to screen various antcins and non-antcins for binding affinity and interaction type with 3CLPro. Further, these compounds were subjected to study their inhibitory effects on 3CLPro activity in vitro. Our results indicate that antcin-B has the best binding affinity by contacting residues like Leu141, Asn142, Glu166, and His163 via hydrogen bond and salt bridge and significantly inhibits 3CLPro activity, surpassing the positive control compound (GC376). The 100 ns molecular dynamics simulation studies showed that antcin-B formed consistent, long-lasting water bridges with Glu166 for their inhibitory activity. In summary, antcin-B could be useful to develop therapeutically viable drugs to inhibit SARS-CoV-2 replication alone or in combination with medications specific to other SARS-CoV-2 viral targets.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as coronavirus disease-2019 (COVID-19), is a pandemic disease that has been declared as modern history’s gravest health ...emergency worldwide. Until now, no precise treatment modality has been developed. The angiotensin-converting enzyme 2 (ACE2) receptor, a host cell receptor, has been found to play a crucial role in virus cell entry; therefore, ACE2 blockers can be a potential target for anti-viral intervention. In this study, we evaluated the ACE2 inhibitory effects of 10 essential oils. Among them, geranium and lemon oils displayed significant ACE2 inhibitory effects in epithelial cells. In addition, immunoblotting and qPCR analysis also confirmed that geranium and lemon oils possess potent ACE2 inhibitory effects. Furthermore, the gas chromatography-mass spectrometry (GC–MS) analysis displayed 22 compounds in geranium oil and 9 compounds in lemon oil. Citronellol, geraniol, and neryl acetate were the major compounds of geranium oil and limonene that represented major compound of lemon oil. Next, we found that treatment with citronellol and limonene significantly downregulated ACE2 expression in epithelial cells. The results suggest that geranium and lemon essential oils and their derivative compounds are valuable natural anti-viral agents that may contribute to the prevention of the invasion of SARS-CoV-2/COVID-19 into the human body.
► Toona sinensis leaf extracts (TS extracts) arrested HL-60 cell growth at G1-S transition phase. ► TS extracts induced cell-cycle arrest was mediated by ROS generation in HL-60 cells. ► TS extracts ...inhibited VEGF expression and release in HL-60 cells. ► TS extracts delayed tumor progression in HL-60 xenograft nude mice.
Toona sinensis is one of the most popular vegetarian cuisines in Taiwan and it has been shown to induce apoptosis in cultured human premyelocytic leukemia (HL-60) cells. In the present study, we examined the effects of T. sinensis leaf extracts (TS extracts) on tumor regression using in vitro cell culture and an in vivo athymic nude mice model. We found that TS extracts (10–75μg/mL) arrested HL-60 cells at the G1-S transition phase through the reductions of Cyclin D1, CDK4, Cyclin E, CDK2, and Cyclin A, and induction of CDK inhibitor p27KIP levels. Furthermore, VEGF expression and release was significantly inhibited by TS extracts. Notably, TS extracts treatment was effective in terms of delaying tumor incidence in the nude mice inoculated with HL-60 cells as well as reducing the tumor burden. Histological analysis confirmed that TS extracts significantly modulated tumor progression in xenograft tumor. Furthermore, a similar pattern of results were observed from gallic acid (5 and 10μg/mL), a major compound in TS, caused G1 arrest through regulations of cell-cycle regulatory proteins. Our data suggest that T. sinensis exerts antiproliferative effects on HL-60 cells in vitro and in vivo due mainly to the presence of gallic acid.
•Lucidone protected human skin keratinocytes (HaCaT) from AAPH-induced cell death.•Lucidone inhibited AAPH-induced ROS generation, lipid peroxidation, and DNA damage.•The antioxidant potential of ...lucidone was directly correlated with Nrf2 activity.•Lucidone inhibited AAPH-induced inflammatory PGE2 production and COX-2 expression.•Lucidone suppressed AAPH-induced NF-κB and MAPKs signaling pathways.
We investigated the protective effects of lucidone, a naturally occurring cyclopentenedione isolated from the fruits of Lindera erythrocarpa Makino, against free-radical and inflammation stimulator 2,2′-azobis (2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress in human keratinocyte (HaCaT) cells, with the aim of revealing the possible mechanisms underlying the protective efficacy. Lucidone pretreatment (0.5–10μg/mL) markedly increased HaCaT cell viability and suppressed AAPH-induced reactive oxygen species (ROS) generation, lipid peroxidation, and DNA damage. Notably, the antioxidant potential of lucidone was directly correlated with the increased expression of an antioxidant gene, heme oxygenase 1 (HO-1), which was followed by the augmentation of the nuclear translocation and transcriptional activation of NF-E2-related factor-2 (Nrf2), with or without AAPH. Nrf2 knockdown diminished the protective effects of lucidone. We also observed that lucidone pretreatment inhibited AAPH-induced inflammatory chemokine prostaglandin E2 (PGE2) production and the expression of cyclooxygenase-2 (COX-2) in HaCaT cells. Lucidone treatment also significantly inhibited AAPH-induced nuclear factor-κB (NF-κB) activation and suppressing the degradation of inhibitor-κB (I-κB). Furthermore, lucidone significantly diminished AAPH-induced COX-2 expression through the down-regulation of the extracellular signal-regulated kinase (ERK) and p38 MAPK signaling pathways. Therefore, lucidone may possess antioxidant and anti-inflammatory properties and may be useful for the prevention of free radical-induced skin damage.
Display omitted
► Lucidone treatment suppressed EtOH-induced hepatic enzymes and lipid peroxidation. ► Alcohol-exposure elevate NO production in hepatic cells. ► Lucidone treatment up-regulates HO-1 ...and Nrf-2 expression. ► Lucidone-mediated induction of HO-1 and Nrf2 expression are stress-dependent.
Lucidone was previously reported to exhibit anti-inflammatory activity in vitro and in vivo. In the present study, we characterized the mechanisms underlying the hepatoprotective effect of lucidone against alcohol-induced oxidative stress in vitro. Human hepatoma (HepG2) cells were pretreated with lucidone (1–10μg/mL) and then hepatotoxicity was stimulated by the addition ethanol (100mM). With response to ethanol-challenge, increased amount of alanine aminotransferase (ALT) and aspirate aminotransferase (AST) release were observed, whereas lucidone pretreatment significantly inhibited the leakage of AST and ALT in HepG2 cells without appreciable cytotoxic effects. We also found that lucidone pretreatment significantly decreased ethanol-induced nitric oxide (NO), tumor necrosis factor-α (TNF-α), malondialdehyde (MDA), reactive oxygen species (ROS) and glutathione (GSH) depletion in HepG2 cells. Furthermore, Western blot and quantitative-PCR analyses showed that ethanol-exposure apparently down-regulated endogenous anti-oxidant hemoxygenase-1 (HO-1) expression, whereas pretreatment with lucidone significantly up-regulates HO-1 expression followed by the transcriptional activation of NF-E2 related factor-2 (Nrf-2). Interestingly, the profound up-regulation of HO-1 and Nrf-2 were observed in only ethanol-challenged cells, which evidenced that lucidone-induced induction of HO-/Nrf-2 were specific with oxidative stress. Thus, we concluded that lucidone-mediated up-regulation of phase-II enzymes and HO-1 via Nrf-2 signaling pathway may provide a pivotal mechanism for its hepatoprotective action.
Abstract
Therapeutic administration of glucocorticoids (GCs) is frequently used as add-on chemotherapy for palliative purposes during breast cancer treatment. Recent studies have shown that GC ...treatment induces microRNA-708 in ovarian cancer cells, resulting in impaired tumor cell proliferation and metastasis. However, the regulatory functions of GCs on miR-708 and its downstream target genes in human breast cancer cells (BCCs) are poorly understood. In this study, we found that treatment with either the synthetic GC dexamethasone (DEX) or the natural GC mimic, antcin A (ATA) significantly increased miR-708 expression by transactivation of glucocorticoid receptor alpha (GRα) in MCF-7 and MDA-MB-231 human BCCs. Induction of miR-708 by GR agonists resulted in inhibition of cell proliferation, cell-cycle progression, cancer stem cell (CSC)-like phenotype and metastasis of BCCs. In addition, GR agonist treatment or miR-708 mimic transfection remarkably inhibited IKKβ expression and suppressed nuclear factor-kappaB (NF-κB) activity and its downstream target genes, including COX-2, cMYC, cyclin D1, Matrix metalloproteinase (MMP)-2, MMP-9, CD24, CD44 and increased p21CIP1 and p27KIP1 that are known to be involved in proliferation, cell-cycle progression, metastasis and CSC marker protein. BCCs xenograft models indicate that treatment with GR agonists significantly reduced tumor growth, weight and volume. Overall, our data strongly suggest that GR agonists induced miR-708 and downstream suppression of NF-κB signaling, which may be applicable as a novel therapeutic intervention in breast cancer treatment.
PDF
