Evaluation of the anticancer effects exerted by 5-fluorouracil and heme oxygenase-1 inhibitor hybrids in HTC116 colorectal cancer cells.

Colon cancer remains a clinical challenge in industrialised countries. Its treatment with 5-Flurouracil (5-FU) develops many side effects and resistance. Thus, several strategies have been undertaken so far, including the use of drug cocktails and polypharmacology. Heme oxygenase-1 (HO-1) is an emerging molecular target in the treatment of various cancers. We recently demonstrated that a combination of HO-1 inhibitors with 5-FU and the corresponding hybrids SI1/17, SI1/20, and SI1/22, possessed anticancer activity against prostate and lung cancer cells. In this work, we evaluated these hybrids in a model of colon cancer and found that SI1/22 and the respective combo have greater potency than 5-FU. Particularly, compounds inhibit HO-1 activity in cell lysates, increase ROS and the expression of HO-1, SOD, and Nrf2. Moreover, we observed a decrease of pro-caspase and an increase in cleaved PARP-1 and p62, suggesting apoptotic and autophagic cell death and potential application of these drugs as anticancer agents.

Inhibition of Heme Oxygenase-1 by Zinc Protoporphyrin IX Improves Adverse Pregnancy Outcomes in Malaria During Early Gestation.

The enzyme heme oxygenase-1 (HO-1) has cytoprotective effects by catalyzing the degradation of heme to produce carbon monoxide, iron and biliverdin. Furthermore, HO-1 activity has been associated with successful pregnancy. On the other hand, in the context of certain inflammatory conditions, HO-1 can induce iron overload and cell death. To investigate the role of HO-1 in gestational malaria, pregnant BALB/c mice were infected with Plasmodium berghei ANKA in early, mid and late gestation. We found that malaria affected the pregnancy outcome in the three periods evaluated. However, only poor pregnancy outcomes in early pregnancy were related to HO-1 upregulation, iron overload, lipid peroxidation and necrosis of the decidua, which were prevented by HO-1 inhibition. In conclusion, HO-1 expression must be finely tuned in gestational malaria to avoid the deleterious effect of increased enzyme activity.

Synthesis of lathyrane diterpenoid nitrogen-containing heterocyclic derivatives and evaluation of their anti-inflammatory activities.

As our ongoing work on lathyrane diterpenoid derivatization, three series of lathyrane diterpenoid derivatives were designed and synthesized based combination principles, including pyrazole, thiazole and furoxan moieties. Biological evaluation indicated that compound 23d exhibited excellently inhibitory activity on LPS-induced NO production in RAW264.7 cells (IC50 = 0.38 ± 0.18 µM). The preliminary structure-activity relationships (SARs) suggested that phenylsulfonyl substituted furoxan moiety had the strongest ability to improve anti-inflammatory activity of lathyrane diterpenoids. Furthermore, compound 23d significantly reduced the level of ROS. Its molecular mechanism was related to inhibiting the transcriptional activation of Nrf2/HO-1 pathway. Based on these considerations, 23d might be a promising anti-inflammatory agent, which is noteworthy for further exploration.

Methylcobalamin Protects Melanocytes from H2O2-Induced Oxidative Stress by Activating the Nrf2/HO-1 Pathway.

PURPOSE: Oxidative stress is considered a major determinant in the pathogenesis of vitiligo. Methylcobalamin (MeCbl) is an activated form of vitamin B12 that regulates inflammatory factors, counters oxidative stress, and reduces apoptosis in many disease models. However, the specific mechanism of MeCbl repigmentation against vitiligo is unknown. In this study, we explored the effect of MeCbl on melanocytes following hydrogen peroxide (H2O2)-induced oxidative stress. METHODS: We established an oxidative stress model using the immortalized human normal melanocyte cell line PIG1. We used a Cell Counting Kit-8 (CCK-8) to detect drug cytotoxicity, and we measured the melanin content of cells using the NaOH method. Intracellular oxidative damage was assessed by flow cytometry and antioxidant enzyme detection kits. In addition, we assessed the presence of apoptosis by flow cytometry and Western blots. We explored the underlying mechanisms of MeCbl during oxidative stress in melanocytes by analyzing the results of experiments based on real-time quantitative polymerase chain reaction (RT-qPCR), Western blotting, and laser scanning confocal immunofluorescence microscopy. Finally, we repeated the experiments after applying an inhibitor to block the Nrf2 pathway. RESULTS: We found that MeCbl treatment enhanced cell viability, increased melanin content, reduced intracellular reactive oxygen species (ROS) accumulation, increased the activities of antioxidant enzyme superoxide dismutase (SOD) and catalase (CAT), reduced melanocyte apoptosis, and up-regulated the expression of the Nrf2/HO-1 pathway. Moreover, the protective effects of MeCbl were significantly weakened after inhibiting the Nrf2/HO-1 pathway. CONCLUSION: Our results indicate that MeCbl attenuated the H2O2-induced oxidative stress in melanocytes by activating the Nrf2/HO-1 pathway, this suggests that MeCbl may be an effective treatment against vitiligo.

Hemin as a novel candidate for treating COVID-19 via heme oxygenase-1 induction.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the coronavirus disease-19 (COVID-19). More than 143 million cases of COVID-19 have been reported to date, with the global death rate at 2.13%. Currently, there are no licensed therapeutics for controlling SARS-CoV-2 infection. The antiviral effects of heme oxygenase-1 (HO-1), a cytoprotective enzyme that inhibits the inflammatory response and reduces oxidative stress, have been investigated in several viral infections. To confirm whether HO-1 suppresses SARS-CoV-2 infection, we assessed the antiviral activity of hemin, an effective and safe HO-1 inducer, in SARS-CoV-2 infection. We found that treatment with hemin efficiently suppressed SARS-CoV-2 replication (selectivity index: 249.7012). Besides, the transient expression of HO-1 using an expression vector also suppressed the growth of the virus in cells. Free iron and biliverdin, which are metabolic byproducts of heme catalysis by HO-1, also suppressed the viral infection. Additionally, hemin indirectly increased the expression of interferon-stimulated proteins known to restrict SARS-CoV-2 replication. Overall, the findings suggested that HO-1, induced by hemin, effectively suppressed SARS-CoV-2 in vitro. Therefore, HO-1 could be potential therapeutic candidate for COVID-19.

HMOX1 upregulation promotes ferroptosis in diabetic atherosclerosis.

OBJECTIVE: Atherosclerotic vascular disease remains the principal cause of death and disability among patients with type 2 diabetes. Unfortunately, the problem is not adequately resolved by therapeutic strategies with currently available drugs or approaches that solely focus on optimal glycemic control. To identify the key contributors and better understand the mechanism of diabetic atherosclerotic vascular disease, we aimed to elucidate the key genetic characteristics and pathological pathways in atherosclerotic vascular disease through nonbiased bioinformatics analysis and subsequent experimental demonstration and exploration in diabetic atherosclerotic vascular disease. METHODS AND RESULTS: Sixty-eight upregulated and 23 downregulated genes were identified from the analysis of gene expression profiles (GSE30169 and GSE6584). A comprehensive bioinformatic assay further identified that ferroptosis, a new type of programmed cell death and HMOX1 (a gene that encodes heme oxygenase), were vital factors in atherosclerotic vascular disease. We further demonstrated that diabetes significantly increased ferroptosis and HMOX1 levels compared to normal controls. Importantly, the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively attenuated diabetic atherosclerosis, suggesting the causative role of ferroptosis in diabetic atherosclerosis development. At the cellular level, Fer-1 ameliorated high glucose high lipid-induced lipid peroxidation and downregulated ROS production. More importantly, HMOX1 knockdown attenuated Fe2+ overload, reduced iron content and ROS, and alleviated lipid peroxidation, which led to a reduction in ferroptosis in diabetic human endothelial cells. CONCLUSIONS: We demonstrated that HMOX1 upregulation is responsible for the increased ferroptosis in diabetic atherosclerosis development, suggesting that HMOX1 may serve as a potential therapeutic or drug development target for diabetic atherosclerosis.

Discovery of Novel Acetamide-Based Heme Oxygenase-1 Inhibitors with Potent In Vitro Antiproliferative Activity.

Heme oxygenase-1 (HO-1) promotes heme catabolism exercising cytoprotective roles in normal and cancer cells. Herein, we report the design, synthesis, molecular modeling, and biological evaluation of novel HO-1 inhibitors. Specifically, an amide linker in the central spacer and an imidazole were fixed, and the hydrophobic moiety required by the pharmacophore was largely modified. In many tumors, overexpression of HO-1 correlates with poor prognosis and chemoresistance, suggesting the inhibition of HO-1 as a possible antitumor strategy. Accordingly, compounds 7i and 7l-p emerged for their potency against HO-1 and were investigated for their anticancer activity against prostate (DU145), lung (A549), and glioblastoma (U87MG, A172) cancer cells. The selected compounds showed the best activity toward U87MG cells. Compound 7l was further investigated for its in-cell enzymatic HO-1 activity, expression levels, and effects on cell invasion and vascular endothelial growth factor (VEGF) extracellular release. The obtained data suggest that 7l can reduce cell invasivity acting through modulation of HO-1 expression.

Combination of Heme Oxygenase-1 Inhibition and Sigma Receptor Modulation for Anticancer Activity.

Cancer is a multifactorial disease that may be tackled by targeting different signaling pathways. Heme oxygenase-1 (HO-1) and sigma receptors (σRs) are both overexpressed in different human cancers, including prostate and brain, contributing to the cancer spreading. In the present study, we investigated whether HO-1 inhibitors and σR ligands, as well a combination of the two, may influence DU145 human prostate and U87MG human glioblastoma cancer cells proliferation. In addition, we synthesized, characterized, and tested a small series of novel hybrid compounds (HO-1/σRs) 1-4 containing the chemical features needed for HO-1 inhibition and σR modulation. Herein, we report for the first time that targeting simultaneously HO-1 and σR proteins may be a good strategy to achieve increased antiproliferative activity against DU145 and U87MG cells, with respect to the mono administration of the parent compounds. The obtained outcomes provide an initial proof of concept useful to further optimize the structure of HO-1/σRs hybrids to develop novel potential anticancer agents.

8-Formylophiopogonanone B antagonizes doxorubicin-induced cardiotoxicity by suppressing heme oxygenase-1-dependent myocardial inflammation and fibrosis.

Doxorubicin (DOX) is a widely used antitumor drug that causes severe cardiotoxicity in patients; no effective strategy yet exists to address this problem. We previously reported that 8-formylophiopogonanone B (8-FOB), a natural isoflavone in Ophiopogon japonicas, antagonizes paraquat-induced hepatotoxicity. Here, we explored the mechanisms underlying DOX-induced cardiotoxicity as well as whether 8-FOB can alleviate DOX-induced cardiotoxicity. Acute cardiotoxicity was established by injecting C57BL/6J mice with a single dose of DOX (20 mg/kg, intraperitoneal). To elucidate the mechanisms underlying DOX-induced cardiotoxicity, differentially expressed genes between hearts from DOX-treated and control mice were identified from the Gene Expression Omnibus (GEO) database via GEO2R. Using the Cytoscape software plugin cytoHubba, five hub genes associated with DOX-induced cardiotoxicity were identified: CD68, PTEN, SERPINE1, AIF1, and HMOX1. However, of these, only HMOX1 protein expression levels were significantly increased after DOX treatment. We also confirmed that HMOX1-dependent myocardial inflammation and fibrosis were closely associated with DOX-induced cardiotoxicity. More importantly, 8-FOB protected against DOX-cardiotoxicity by ameliorating cardiac injury and dysfunction, reducing cardiac fibrosis and inflammatory cytokine release, and inhibiting HMOX1 expression. In conclusion, our results suggest that inhibition of HMOX1-dependent myocardial inflammatory insults and fibrosis is essential for 8-FOB to ameliorate DOX-caused cardiotoxicity.

ATF4-dependent heme-oxygenase-1 attenuates diabetic nephropathy by inducing autophagy and inhibiting apoptosis in podocyte.

AIM: Podocyte injury plays an important role in diabetic nephropathy (DN), yet the underlying molecular mechanisms of podocyte injury in DN is not clear. Here, we investigated the role of activating transcription factor 4 (ATF4) and HO-1 in DN-induced podocyte injury. METHODS: Protein expression was measured by western blotting (WB) and immunofluorescence. Cellular apoptosis was quantified by flow cytometry. ATF4 siRNA knockdown and HO-1 overexpression in podocyte were employed to evaluate the role of ER stress in DN-induced apoptosis and autophagy response. Urinary protein levels, nephrin expression, serum creatinine and BUN were evaluated and glomerulosclerosis was quantified by Periodic Acid-Schiff staining. RESULTS: Expression of ATF4 was increased in podocytes exposed to serum from DN mice. ATF4 knockdown enhanced DN-induced podocyte apoptosis. HO-1 overexpression reduced the decline of DN-induced podocyte autophagy and inhibited apoptosis and the beneficial effects of HO-1 overexpression in DN were blocked by ATF4 knockdown. The diabetic mice were significantly ameliorated by HO-1 agonist hemin treatment. CONCLUSIONS: ATF4 induces autophagy by enhancing the expression of HO-1, and inhibits podocyte apoptosis in DN. Treatment with the HO-1 agonist reduced proteinuria, apoptosis, and enhanced autophagy response, and thus improved renal function in DN mice.

HO-1: A new potential therapeutic target to combat osteoporosis.

Heme oxygenase-1 (HO-1) exerts a protective effect against cell damage and induces the activity of many enzymes involved in the treatment of many human diseases, including osteoporosis. The increasing prevalence of osteoporosis and the limitations of the current treatments available led to a continuous occurrence of bone loss and osteoporotic fractures, highlighting the need of a better understanding of the mechanism and function of HO-1. Many factors cause osteoporosis, including lack of estrogen, aging, and iron overload, and they either cause the increase in inflammatory factors or the increase in reactive oxygen species to break bone reconstruction balance. Therefore, regulating the production of inflammatory factors and reactive oxygen species may become a strategy for the treatment of osteoporosis. Solid evidence showed that the overexpression of HO-1 compensates high oxidation levels by increasing intracellular antioxidant levels and reduces inflammation by suppressing pro-inflammatory factors. Some extracts can target HO-1 and ameliorate osteoporosis. However, no systematic report is available on therapies targeting HO-1 to combat osteoporosis. Therefore, this review summarizes the biological characteristics of HO-1, and the relationship between inflammatory response and reactive oxygen species production regulated by HO-1 and osteoporosis. The understanding of the role of HO-1 in osteoporosis may provide ideas for a potential clinical treatment and new drugs targeting HO-1.

Isorhamnetin Alleviates High Glucose-Aggravated Inflammatory Response and Apoptosis in Oxygen-Glucose Deprivation and Reoxygenation-Induced HT22 Hippocampal Neurons Through Akt/SIRT1/Nrf2/HO-1 Signaling Pathway.

This study is aimed at exploring the potential of isorhamnetin in protection against diabetes-exacerbated ischemia/reperfusion-induced brain injury and elucidating its action mechanism. After establishment of the model of high glucose (HG)-aggravated oxygen-glucose deprivation and reoxygenation (OGD/R), HT22 cell viability was detected by CCK-8. Lactate dehydrogenase (LDH) activity, casapase-3 activity, and oxidative stress-related markers in HT22 cells were detected by corresponding commercial kits. The apoptosis of HG-treated HT22 cells following OGD/R was observed with TUNEL staining. The level of pro-inflammatory cytokines was examined by ELISA. The expression of Akt/SIRT1/Nrf2/HO-1 signaling-related proteins was assayed by Western blot. The results showed that HG noticeably worsened the OGD/R-induced apoptosis of HT22 cells. Isorhamnetin relieved the HG-aggravated OGD/R-induced apoptosis, inflammatory response, and oxidative stress of HT22 cells. Isorhamnetin alleviated the HG-aggravated OGD/R injury in HT22 cells through Akt/SIRT1/Nrf2/HO-1 signaling pathway. Meanwhile, treatment with Akt inhibitor LY294002 reversed the protective effects of isorhamnetin against HG-aggravated OGD/R injury in HT22 cells. In a conclusion, Isorhamnetin alleviates HG-aggravated OGD/R in HT22 hippocampal neurons through Akt/SIRT1/Nrf2/HO-1 signaling pathway.

Heme catabolism by tumor-associated macrophages controls metastasis formation.

Although the pathological significance of tumor-associated macrophage (TAM) heterogeneity is still poorly understood, TAM reprogramming is viewed as a promising anticancer therapy. Here we show that a distinct subset of TAMs (F4/80hiCD115hiC3aRhiCD88hi), endowed with high rates of heme catabolism by the stress-responsive enzyme heme oxygenase-1 (HO-1), plays a critical role in shaping a prometastatic tumor microenvironment favoring immunosuppression, angiogenesis and epithelial-to-mesenchymal transition. This population originates from F4/80+HO-1+ bone marrow (BM) precursors, accumulates in the blood of tumor bearers and preferentially localizes at the invasive margin through a mechanism dependent on the activation of Nrf2 and coordinated by the NF-κB1-CSF1R-C3aR axis. Inhibition of F4/80+HO-1+ TAM recruitment or myeloid-specific deletion of HO-1 blocks metastasis formation and improves anticancer immunotherapy. Relative expression of HO-1 in peripheral monocyte subsets, as well as in tumor lesions, discriminates survival among metastatic melanoma patients. Overall, these results identify a distinct cancer-induced HO-1+ myeloid subgroup as a new antimetastatic target and prognostic blood marker.

The signaling pathway PI3K/Akt/Nrf2/HO-1 plays a role in the mitochondrial protection promoted by astaxanthin in the SH-SY5Y cells exposed to hydrogen peroxide.

The mitochondria are the major source of reactive species in the mammalian cells. Hydrogen peroxide (H2O2) is a potent inducer of redox impairment by a mechanism, at least in part, dependent on its ability to impair mitochondrial function. H2O2 plays an important role in several pathological conditions, including neurodegeneration and cardiovascular diseases. Astaxanthin (AST) is a xanthophyll that may be found in microalgae, crustaceans, and salmon and exhibits antioxidant and anti-inflammatory effects in different cell types. Even though there is evidence pointing to a role for AST as mitochondrial protectant agent, it was not clearly demonstrated how this xanthophyll attenuates mitochondrial stress. Therefore, we investigated here whether and how AST would be able to prevent the H2O2-induced mitochondrial dysfunction in the human neuroblastoma SH-SY5Y cells. We found that AST (20 µM) prevented the H2O2-induced loss of mitochondrial membrane potential (MMP) and decrease in the activity of the Complexes I and V. AST pretreatment blocked the mitochondria-related pro-apoptotic effects elicited by H2O2. AST upregulated the enzyme heme oxygenase-1 (HO-1) and the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) by a mechanism dependent on the phosphoinositide 3-kinase/Akt (PI3K/Akt) signaling pathway. Inhibition of the PI3K/Akt or of the HO-1 enzyme abolished the AST-induced mitochondrial protection in cells challenged with H2O2. Silencing of Nrf2 caused similar effects. Thus, we suggest that AST promotes mitochondrial protection by a mechanism dependent on the PI3K/Akt/Nrf2/HO-1 signaling pathway in SH-SY5Y cells exposed to H2O2.

Loganin Attenuates Septic Acute Renal Injury with the Participation of AKT and Nrf2/HO-1 Signaling Pathways.

PURPOSE: Sepsis, a destructive inflammatory response syndrome, is the principal reason to induce death in the intensive care unit. Loganin has been proved to possess the property of anti-inflammation, antioxidant, neuroprotection, and sedation. The primary aim of this study was to evaluate whether Loganin could alleviate acute kidney injury (AKI) during sepsis and investigate the latent mechanisms. METHODS: Septic AKI models were established by cecal ligation and puncture (CLP) surgery in mice and given Loganin (20, 40, 80 mg/kg) by gavage. Lipopolysaccharides (LPS)-stimulated human kidney proximal tubular (HK2) cells incubated in Loganin (5, 10, 20 µ M) were used to explore the accurate mechanisms. Survival rate, renal function (creatinine and blood urea nitrogen), and renal pathological changes were detected in septic mice. Oxidative stress markers (SOD, GSH-Px, MDA, and SOD), mitochondrial membrane potential, mitochondrial calcium overload, and nuclear factor E2-related factor 2 (Nrf2)/heme-oxygenase 1 (HO-1) pathway activation in vivo and in vitro were determined by commercial kits and Western blot. Cell apoptosis, apoptotic-related protein (cleaved caspase-3, Bcl-2, and Bax) expression and protein kinase B (AKT) phosphorylation in vivo and in vitro were measured by TUNEL staining and Western blot. Finally, AKT blockage by 10 µM LY294002 or Nrf2 inhibition by10 µ M ML385 were utilized to prove the involvement of AKT and Nrf2/HO-1 pathway in AKI during sepsis. RESULTS: We found Loganin treatment (20, 40, 80 mg/kg) mitigated septic AKI reflected by elevated renal function and palliative pathological changes. Oxidative stress and apoptosis in the kidney and LPS-treated HK2 cells were also inhibited by Loganin administration, which was accompanied by AKT and Nrf2/HO-1 pathway activation. Besides, the protective effects of Loganin could be diminished by AKT or Nrf2 blockage, indicating the involvement of AKT and Nrf2/HO-1 pathway. CONCLUSION: The results suggested that the protective effects of Loganin on AKI during sepsis might be mediated by AKT and Nrf2/HO-1 pathway signaling activation in kidney proximal tubular cells.

Heme oxygenase-1 inhibition promotes IFNγ- and NOS2-mediated control of Mycobacterium tuberculosis infection.

Mycobacterium tuberculosis (Mtb) infection induces pulmonary expression of the heme-degrading enzyme heme oxygenase-1 (HO-1). We have previously shown that pharmacological inhibition of HO-1 activity in experimental tuberculosis results in decreased bacterial loads and unexpectedly that this outcome depends on the presence of T lymphocytes. Here, we extend these findings by demonstrating that IFNγ production by T lymphocytes and NOS2 expression underlie this T-cell requirement and that HO-1 inhibition potentiates IFNγ-induced NOS2-dependent control of Mtb by macrophages in vitro. Among the products of heme degradation by HO-1 (biliverdin, carbon monoxide, and iron), only iron supplementation reverted the HO-1 inhibition-induced enhancement of bacterial control and this reversal was associated with decreased NOS2 expression and NO production. In addition, we found that HO-1 inhibition results in decreased labile iron levels in Mtb-infected macrophages in vitro and diminished iron accumulation in Mtb-infected lungs in vivo. Together these results suggest that the T-lymphocyte dependence of the therapeutic outcome of HO-1 inhibition on Mtb infection reflects the role of the enzyme in generating iron that suppresses T-cell-mediated IFNγ/NOS2-dependent bacterial control. In broader terms, our findings highlight the importance of the crosstalk between iron metabolism and adaptive immunity in determining the outcome of infection.

Protective role of microglial HO-1 blockade in aging: Implication of iron metabolism.

Heme oxygenase-1 (HO-1) is an inducible enzyme known for its anti-inflammatory, antioxidant and neuroprotective effects. However, increased expression of HO-1 during aging and age-related neurodegenerative diseases have been associated to neurotoxic ferric iron deposits. Being microglia responsible for the brain's innate immune response, the aim of this study was to understand the role of microglial HO-1 under inflammatory conditions in aged mice. For this purpose, aged wild type (WT) and LysMCreHmox1△△ (HMOX1M-KO) mice that lack HO-1 in microglial cells, were used. Aged WT mice showed higher basal expression levels of microglial HO-1 in the brain than adult mice. This increase was even higher when exposed to an inflammatory stimulus (LPS via i.p.) and was accompanied by alterations in different iron-related metabolism proteins, resulting in an increase of iron deposits, oxidative stress, ferroptosis and cognitive decline. Furthermore, microglia exhibited a primed phenotype and increased levels of inflammatory markers such as iNOS, p65, IL-1ß, TNF-α, Caspase-1 and NLRP3. Interestingly, all these alterations were prevented in aged HMOX1M-KO and WT mice treated with the HO-1 inhibitor ZnPPIX. In order to determine the effects of microglial HO-1-dependent iron overload, aged WT mice were treated with the iron chelator deferoxamine (DFX). DFX caused major improvements in iron, inflammatory and behavioral alterations found in aged mice exposed to LPS. In conclusion, this study highlights how microglial HO-1 overexpression contributes to neurotoxic iron accumulation providing deleterious effects in aged mice exposed to an inflammatory insult.

PTP1B Inhibitory and Anti-inflammatory Properties of Constituents from Eclipta prostrata L.

The white-flowered leaves of Eclipta prostrata L. together with leaves of Scoparia dulcis and Cynodon dactylon are mixedly boiled in water and given to diabetic patients resulting in the significant improvement in the management of diabetes. However, the active constituents from this plant for antidiabetic and anti-obesity properties are remaining unclear. Thus, this study was to discover anti-diabetes and anti-obesity activities through protein tyrosine phosphatases (PTP)1B inhibitory effects. We found that the fatty acids (23, 24) showed potent PTP1B inhibition with IC50 values of 2.14 and 3.21 µM, respectively. Triterpenoid-glycosides (12-15) also exhibited strong to moderate PTP1B inhibitory effects, with IC50 values ranging from 10.88 to 53.35 µM. Additionally, active compounds were investigated for their PTP1B inhibitory mechanism and docking analysis. On the other hand, the anti-inflammatory activity from our study revealed that compounds (1-4, 7, 8, 10) displayed the significant inhibition nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Especially, compound 9 showed the potent inhibitory effects in LPS-induced NO production on RAW264.7 cell. Therefore, further Western blot analysis was performed to identify the inhibitory expression including heme oxygenase-1 (HO-1) and inhibitor of kappaB (IκB) phosphorylation.

trans-Cinnamaldehyde Prevents Oxidative Stress-Induced Apoptosis in V79-4 Chinese Hamster Lung Fibroblasts through the Nrf2-Mediated HO-1 Activation.

Oxidative stress, which is characterized by overproduction of reactive oxygen species (ROS), is considered a major risk factor associated with fibroblast death in severe lung diseases such as idiopathic pulmonary fibrosis. trans-Cinnamaldehyde (tCA), the major phytochemical constituent in cinnamon, is known to possess strong anti-oxidant activity. However, whether tCA can defend lung fibroblasts against oxidative injury remains to be elucidated. Therefore, this study was conducted to investigate the protective effects of tCA on oxidative stress in V79-4 Chinese hamster lung fibroblasts. The current results showed that tCA inhibited hydrogen peroxide (H2O2)-induced cytotoxicity by blocking abnormal accumulation of ROS in V79-4 Chinese hamster lung fibroblasts. tCA attenuated apoptosis by suppressing of mitochondrial dysfunction and cytosolic release of cytochrome c, increasing the rate of Bcl-2/Bax expression and reducing the activity of caspase-9 and caspase-3 in H2O2-stimulated V79-4 cells, suggesting that tCA protected V79-4 cells from the induction of mitochondria-mediated apoptosis by H2O2. Additionally, the activation of nuclear factor-erythroid-2-related factor 2 (Nrf2) was markedly promoted by tCA in the presence of H2O2, which was associated with the enhanced expression of heme oxygenase-1 (HO-1). However, inhibiting the activity of HO-1 by zinc protoporphyrin IX, a potent inhibitor of HO-1, eliminated the ROS scavenging and protective effects of tCA, indicating that tCA was able to protect V79-4 lung fibroblasts from H2O2-induced oxidative stress by activating the Nrf2 signaling pathway. Therefore, it is suggested that tCA may be useful as a candidate for the treatment of oxidative stress-mediated lung injuries in the future.