The efficacy and safety of a fixed-dose combination of apocynin and paeonol, APPA, in symptomatic knee OA: A double-blind, randomized, placebo-controlled, clinical trial.

OBJECTIVE: Apocynin (AP) and paeonol (PA) are low molecular weight phenolic compounds with a broad array of anti-inflammatory and immunoregulatory effects. This study assessed of a fixed-dose combination of APPA in people with symptomatic knee osteoarthritis (OA). METHODS: A multi-center, randomized, placebo-controlled, double-blind phase 2a trial enrolled participants with radiographic knee OA (Kellgren-Lawrence, KL, grades 2-3) and pain ≥40/100 on WOMAC pain subscale, and evaluated the efficacy and safety of oral APPA over a 28-day period. APPA 800 mg or matching placebo was administered twice daily in a 1:1 ratio. Post-hoc analyses explored the response to APPA in sub-groups with more severe pain and structural severity. RESULTS: The two groups were comparable at baseline; 152 subjects were enrolled and 148 completed the trial. There was no statistically significant difference between groups with respect to the primary outcome, WOMAC pain (mean difference between groups was -0.89, 95% CI: -5.62, 3.84, p = 0.71), nor WOMAC function or WOMAC total. However, predefined subgroup analyses of subjects with symptoms compatible with nociplastic/neuropathic pain features showed a statistically significant effect of APPA compared to placebo. Adverse events (mainly gastrointestinal) were mild to moderate. CONCLUSION: Treatment with APPA 800 mg twice daily for 28 days in subjects with symptomatic knee OA was not associated with significant symptom improvement compared to placebo. The treatment was well-tolerated and safe. While the study was not powered for such analysis, pre-planned subgroup analyses showed a significant effect of APPA in subjects with nociplastic pain/severe OA, indicating that further research in the effects of APPA in appropriate patients is warranted.

Protective effects of paeonol against cognitive impairment in lung diseases.

Pulmonary inflammation may lead to neuroinflammation resulting in neurological dysfunction, and it is associated with a variety of acute and chronic lung diseases. Paeonol is a herbal phenolic compound with anti-inflammatory and anti-oxidative properties. The aim of this study is to understand the beneficial effects of paeonol on cognitive impairment, pulmonary inflammation and its underlying mechanisms. Pulmonary inflammation-associated cognitive deficit was observed in TNFα-stimulated mice, and paeonol mitigated the cognitive impairment by reducing the expressions of interleukin (IL)-1ß, IL-6, and NOD-like receptor family pyrin domain-containing 3 (NLRP3) in hippocampus. Moreover, elevated plasma miR-34c-5p in lung-inflamed mice was also reduced by paeonol. Pulmonary inflammation induced by intratracheal instillation of TNFα in mice resulted in immune cells infiltration in bronchoalveolar lavage fluid, pulmonary edema, and acute fibrosis, and these inflammatory responses were alleviated by paeonol orally. In MH-S alveolar macrophages, tumor necrosis factor (TNF) α- and phorbol myristate acetate (PMA)-induced inflammasome activation was ameliorated by paeonol. In addition, the expressions of antioxidants were elevated by paeonol, and reactive oxygen species production was reduced. In this study, paeonol demonstrates protective effects against cognitive deficits and pulmonary inflammation by exerting anti-inflammatory and anti-oxidative properties, suggesting a powerful benefit as a potential therapeutic agent.

Protective mechanism of Paeonol on central nervous system.

Cerebrovascular diseases involve neuronal damage, resulting in degenerative neuropathy and posing a serious threat to human health. The discovery of effective drug components from natural plants and the study of their mechanism are a research idea different from chemical synthetic medicines. Paeonol is the main active component of traditional Chinese medicine Paeonia lactiflora Pall. It widely exists in many medicinal plants and has pharmacological effects such as anti-atherosclerosis, antiplatelet aggregation, anti-oxidation, and anti-inflammatory, which keeps generally used in the treatment of cardiovascular and cerebrovascular diseases. Based on the therapeutic effects of Paeonol for cardiovascular and cerebrovascular diseases, this article reviewed the pharmacological effects of Paeonol in Alzheimer's disease, Parkinson's disease, stroke, epilepsy, diabetes encephalopathy, and other neurological diseases, providing a reference for the research of the mechanism of Paeonol in central nervous system diseases.

Novel insulin sensitizer MSDC-0602K improves insulinemia and fatty liver disease in mice, alone and in combination with liraglutide.

Insulin sensitizers and incretin mimetics are antidiabetic agents with vastly different mechanisms of action. Thiazolidinedione (TZD) insulin sensitizers are associated with weight gain, whereas glucagon-like peptide-1 receptor agonists can induce weight loss. We hypothesized that combination of a TZD insulin sensitizer and the glucagon-like peptide-1 receptor agonist liraglutide would more significantly improve mouse models of diabetes and nonalcoholic steatohepatitis (NASH). Diabetic db/db and MS-NASH mice were treated with the TZD MSDC-0602K by oral gavage, liraglutide (Lira) by s.c. injection, or combination 0602K+Lira. Lira slightly reduced body weight and modestly improved glycemia in db/db mice. Comparatively, 0602K-treated and 0602K+Lira-treated mice exhibited slight weight gain but completely corrected glycemia and improved glucose tolerance. 0602K reduced plasma insulin, whereas Lira further increased the hyperinsulinemia of db/db mice. Surprisingly, 0602K+Lira treatment reduced plasma insulin and C-peptide to the same extent as mice treated with 0602K alone. 0602K did not reduce glucose-stimulated insulin secretion in vivo, or in isolated islets, indicating the reduced insulinemia was likely compensatory to improved insulin sensitivity. In MS-NASH mice, both 0602K or Lira alone improved plasma alanine aminotransferase and aspartate aminotransferase, as well as liver histology, but more significant improvements were observed with 0602K+Lira treatment. 0602K or 0602K+Lira also increased pancreatic insulin content in both db/db and MS-NASH mice. In conclusion, MSDC-0602K corrected glycemia and reduced insulinemia when given alone, or in combination with Lira. However, 0602K+Lira combination more significantly improved glucose tolerance and liver histology, suggesting that this combination treatment may be an effective therapeutic strategy for diabetes and NASH.

Paeonol enhances treatment of fluconazole and amphotericin B against oropharyngeal candidiasis through HIF-1α related IL-17 signaling.

Oropharyngeal candidiasis (OPC) is an oral infection mainly caused by Candida albicans, a dimorphic human opportunistic pathogen that can proliferate and invade the superficial oral epithelium using its hyphae. The filamentation of C. albicans is a hallmark of biofilm formation, accompanied by the occurrence of a hypoxic microenvironment. Paeonol (PAE) is a traditional medicine with multiple properties. In a previous study, we demonstrated the synergism of PAE plus Fluconazole (FLU) or Amphotericin B (AmB) against C. albicans in vitro and in vivo. This study aimed to explore the therapeutic mechanisms of drug combinations on OPC. In an established OPC mouse model, the culture of hypoxia was observed by calcofluor white and hypoxyprobe staining. The expression and levels of IL-17 signaling-associated genes and proteins (IL-17A and IL-23) were evaluated in tissue homogenates and EC109 cells. The results show that compared with the single therapy, PAE plus FLU or AmB can decrease fungal burden, restore mucosal integrity, and reduce the hypoxic microenvironment and inflammation in the OPC mice. Relative to infected mice, the drug combinations can also rectify the abnormal expression of hypoxia inducible factor (hif)-1α, il-17a, and il-23 mRNA. Meanwhile, compared with the infected EC109 cells treated with a single drug, PAE plus FLU or AmB significantly inhibited the mRNA and protein expression of HIF-1α, IL-17A, and IL-23. Taken together, the possible mechanism of PAE plus FLU or AmB can be attributed to the regulation of hypoxia-associated IL-17 signaling in OPC treatment.

Paeonol inhibits inflammatory response and protects chondrocytes by upregulating sirtuin 1.

Paeonol is the bioactive component in Paeonia lactiflora Pall., Cynanchum paniculatum and Paeonia × suffruticosa Andr. Paeonol has been previously demonstrated to inhibit the release of tumor necrosis factor α (TNF-α) and interluekin 6 (IL-6) in chondrocytes. Sirtuin 1 (SIRT1) is downregulated in degraded cartilage and paeonol could induce nuclear accumulation of SIRT1. Therefore, the present study aims to investigate the possible role of paeonol in chondrocyte inflammation and cartilage protection in osteoarthritis (OA) as well as its regulation of SIRT1. Primary chondrocytes from rat knee joints were transfected with short hairpin (sh) - SIRT1 and (or) paeonol prior to IL-1ß exposure, and then inflammatory response, apoptosis, and extracellular matrix (ECM) degradation in the cells were evaluated concurrent with the activation of the nuclear factor κß (NF-κß) signaling pathway. Increased levels of TNF-α, IL-17, IL-6, matrix metalloproteinase 1 (MMP-1), MMP-3, and MMP-13 along with decreased tissue inhibitor of metalloproteinases 1 and type II collagen levels were found in IL-1ß-stimulated chondrocytes. Chondrocyte apoptosis was elevated and the NF-κß signaling pathway was activated in response to IL-1ß treatment. Paeonol enhanced SIRT1 expression to inactivate the NF-κß signaling pathway, thereby ameliorating inflammatory cytokine secretion, ECM degradation, and chondrocyte apoptosis. In conclusion, the results of the present study confirm the potential of paeonol as a candidate OA drug.

Paeonol alleviates dextran sodium sulfate induced colitis involving Candida albicans-associated dysbiosis.

Inflammatory bowel disease (IBD), which consists of ulcerative colitis (UC) and Crohn's disease (CD), is a chronic inflammatory disorder of the gastrointestinal tract. Occurrence and development of UC have been associated with multiple potential causative factors, which include fungal dysbiosis. Growing evidence reveals that Candida albicans-associated dysbiosis is correlated with clinical deterioration in UC. Paeonol (PAE) is a commonly used traditional medicine with multiple reported properties including effective alleviation of UC. In this study, a murine UC model was established by colonizing mice with additional C. albicans via gavage prior to dextran sodium sulfate (DSS) administration. Effects of PAE treatment were also assessed at initiation and in preestablished C. albicans-associated colitis. The results showed that C. albicans supplementation could aggravate disease activity index (DAI), compromise mucosal integrity, exacerbate fecal and tissue fungal burdens, increase serum ß-glucan and anti-Saccharomyces cerevisiae antibody (ASCA) levels, promote serum and colonic tissue pro-inflammatory cytokine secretion (tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, and IL-8) and decrease the anti-inflammatory cytokine IL-10 level. It also stimulated Dectin-1, TLR2 and TLR4 as well as expression of their downstream effector NF-κB in colonic tissue. After PAE treatment, the adverse impacts of C. albicans on colitis were relieved, via decreased receptor-associated local and systemic inflammation. Our study suggests that PAE should be a candidate for treatment of fungal dysbiosis-associated UC and may act through the Dectin-1/NF-κB pathway in collaboration with TLR2 and TLR4. LAY SUMMARY: Candida albicans is believed to be an important stimulator in ulcerative colitice (UC) development. Suppressing the growth of intestinal C. albicans can be contributory to the amelioration of UC. Paeonol (PAE) is a commonly used traditional medicine with multiple biological functions. In this study, we observed that PAE could alleviate symptoms in mice UC model accompanying with burden reduction of C. albicans. Therefore, we suppose that PAE can be a candidate in the treatment of C. albicans-associated UC.

Molecular insights of NADPH oxidases and its pathological consequences.

Reactive oxygen species (ROS), formed by the partial reduction of oxygen, were for a long time considered to be a byproduct of cellular metabolism. Since, increase in cellular levels of ROS results in oxidative stress leading to damage of nucleic acids, proteins, and lipids resulting in numerous pathological conditions; ROS was considered a bane for aerobic species. Hence, the discovery of NADPH oxidases (NOX), an enzyme family that specifically generates ROS as its prime product came as a surprise to redox biologists. NOX family proteins participate in various cellular functions including cell proliferation and differentiation, regulation of genes and protein expression, apoptosis, and host defence immunological response. Balanced expression and activation of NOX with subsequent production of ROS are critically important to regulate various genes and proteins to maintain homeostasis of the cell. However, dysregulation of NOX activation leading to enhanced ROS levels is associated with various pathophysiologies including diabetes, cardiovascular diseases, neurodegenerative diseases, ageing, atherosclerosis, and cancer. Although our current knowledge on NOX signifies its importance in the normal functioning of various cellular pathways; yet the choice of ROS producing enzymes which can tip the scale from homeostasis toward damage, as mediators of biological functions remain an oddity. Though the role of NOX in maintaining normal cellular functions is now deemed essential, yet its dysregulation leading to catastrophic events cannot be denied. Hence, this review focuses on the involvement of NOX enzymes in various pathological conditions imploring them as possible targets for therapies. SIGNIFICANCE OF THE STUDY: The NOXs are multi-subunit enzymes that generate ROS as a prime product. NOX generated ROS are usually regulated by various molecular factors and play a vital role in different physiological processes. The dysregulation of NOX activity is associated with pathological consequences. Recently, the dynamic proximity of NOX enzymes with different molecular signatures of pathologies has been studied extensively. It is essential to identify the precise role of NOX machinery in its niche during the progression of pathology. Although inhibition of NOX could be a promising approach for therapeutic interventions, it is critical to expand the current understanding of NOX's dynamicity and shed light on their molecular partners and regulators.

Paeonol ameliorates CFA-induced inflammatory pain by inhibiting HMGB1/TLR4/NF-κB p65 pathway.

The enhanced release of inflammatory cytokines mediated by high mobility group box1 (HMGB1) leads to pain sensation, and has been implicated in the etiology of inflammatory pain. Paeonol (PAE), a major active phenolic component in Cortex Moutan, provides neuroprotective efficacy via exerting anti-inflammatory effect. However, the role and mechanism of PAE in inflammatory pain remain to be fully clarified. In this study, we showed that PAE treatment significantly ameliorated mechanical and thermal hyperalgesia of mice induced by complete Freund's adjuvant (CFA). The analgesic effect of PAE administration was associated with suppressing the enhanced expression of HMGB1 as well as the downstream signaling molecules including toll-like receptor 4 (TLR4), the nuclear NF-κB p65, TNF-α and IL-1ß after CFA insult in the anterior cingulate cortex (ACC), a key brain region responsible for pain processing. Furthermore, inhibition of HMGB1 activity by glycyrrhizin (GLY), an HMGB1 inhibitor, alleviated CFA-induced pain and also facilitated PAE-mediated analgesic effect in mice along with the decreased expression of TLR4, NF-κB p65, TNF-α and IL-1ß upon CFA injury. Collectively, we showed PAE exerted analgesic effect through inhibiting the HMGB1/TLR4/NF-κB p65 pathway and subsequent generation of cytokines TNF-α and IL-1ß in the ACC.

Biological Activities of Paeonol in Cardiovascular Diseases: A Review.

Paeonol is a naturally existing bioactive compound found in the root bark of Paeonia suffruticosa and it is traditionally used in Chinese medicine for the prevention and management of cardiovascular diseases. To date, a great deal of studies has been reported on the pharmacological effects of paeonol and its mechanisms of action in various diseases and conditions. In this review, the underlying mechanism of action of paeonol in cardiovascular disease has been elucidated. Recent studies have revealed that paeonol treatment improved endothelium injury, demoted inflammation, ameliorated oxidative stress, suppressed vascular smooth muscle cell proliferation, and repressed platelet activation. Paeonol has been reported to effectively protect the cardiovascular system either employed alone or in combination with other traditional medicines, thus, signifying it could be a hypothetically alternative or complementary atherosclerosis treatment. This review summarizes the biological and pharmacological activities of paeonol in the treatment of cardiovascular diseases and its associated underlying mechanisms for a better insight for future clinical practices.

2,4,6-Trihydroxy-3-geranyl acetophenone suppresses vascular leakage and leukocyte infiltration in lipopolysaccharide-induced endotoxemic mice.

CONTEXT: Lipopolysaccharide (LPS) exacerbates systemic inflammatory responses and causes excessive fluid leakage. 2,4,6-Trihydroxy-3-geranyl acetophenone (tHGA) has been revealed to protect against LPS-induced vascular inflammation and endothelial hyperpermeability in vitro. OBJECTIVE: This study assesses the in vivo protective effects of tHGA against LPS-induced systemic inflammation and vascular permeability in endotoxemic mice. MATERIALS AND METHODS: BALB/c mice were intraperitoneally pre-treated with tHGA for 1 h, followed by 6 h of LPS induction. Evans blue permeability assay and leukocyte transmigration assay were performed in mice (n = 6) pre-treated with 2, 20 and 100 mg/kg tHGA. The effects of tHGA (20, 40 and 80 mg/kg) on LPS-induced serum TNF-α secretion, lung dysfunction and lethality were assessed using ELISA (n = 6), histopathological analysis (n = 6) and survivability assay (n = 10), respectively. Saline and dexamethasone were used as the negative control and drug control, respectively. RESULTS: tHGA significantly inhibited vascular permeability at 2, 20 and 100 mg/kg with percentage of inhibition of 48%, 85% and 86%, respectively, in comparison to the LPS control group (IC50=3.964 mg/kg). Leukocyte infiltration was suppressed at 20 and 100 mg/kg doses with percentage of inhibition of 73% and 81%, respectively (IC50=17.56 mg/kg). However, all tHGA doses (20, 40 and 80 mg/kg) failed to prevent endotoxemic mice from lethality because tHGA could not suppress TNF-α overproduction and organ dysfunction. DISCUSSION AND CONCLUSIONS: tHGA may be developed as a potential therapeutic agent for diseases related to uncontrolled vascular leakage by combining with other anti-inflammatory agents.

Statin and rottlerin small-molecule inhibitors restrict colon cancer progression and metastasis via MACC1.

MACC1 (Metastasis Associated in Colon Cancer 1) is a key driver and prognostic biomarker for cancer progression and metastasis in a large variety of solid tumor types, particularly colorectal cancer (CRC). However, no MACC1 inhibitors have been identified yet. Therefore, we aimed to target MACC1 expression using a luciferase reporter-based high-throughput screening with the ChemBioNet library of more than 30,000 compounds. The small molecules lovastatin and rottlerin emerged as the most potent MACC1 transcriptional inhibitors. They remarkably inhibited MACC1 promoter activity and expression, resulting in reduced cell motility. Lovastatin impaired the binding of the transcription factors c-Jun and Sp1 to the MACC1 promoter, thereby inhibiting MACC1 transcription. Most importantly, in CRC-xenografted mice, lovastatin and rottlerin restricted MACC1 expression and liver metastasis. This is-to the best of our knowledge-the first identification of inhibitors restricting cancer progression and metastasis via the novel target MACC1. This drug repositioning might be of therapeutic value for CRC patients.

Paeonol Attenuates Methotrexate-Induced Cardiac Toxicity in Rats by Inhibiting Oxidative Stress and Suppressing TLR4-Induced NF-κB Inflammatory Pathway.

Methotrexate (MTX) is a commonly used chemotherapeutic agent. Oxidative stress and inflammation have been proved in the development of MTX toxicity. Paeonol is a natural phenolic compound with various pharmacological activities including antioxidant and anti-inflammatory properties. The aim of the present study was to evaluate the protective effect of paeonol against MTX-induced cardiac toxicity in rats and to evaluate the various mechanisms that underlie this effect. Paeonol (100 mg/kg) was administered orally for 10 days. MTX cardiac toxicity was induced at the end of the fifth day of the experiment, with or without paeonol pretreatment. MTX-induced cardiac damage is evidenced by a distortion in the normal cardiac histological structure, with significant oxidative and nitrosative stress shown as a significant increase in NADPH oxidase-2, malondialdehyde, and nitric oxide levels along with a decrease in reduced glutathione concentration and superoxide dismutase activity compared to the control group. MTX-induced inflammatory effects are evidenced by the increased cardiac toll-like receptor 4 (TLR4) mRNA expression and protein level as well as increased cardiac tumor necrosis factor- (TNF-) α and interleukin- (IL-) 6 levels along with increased nuclear factor- (NF-) κB/p65 immunostaining. MTX increased apoptosis as shown by the upregulation of cardiac caspase 3 immunostaining. Paeonol was able to correct the oxidative and nitrosative stress as well as the inflammatory and apoptotic parameters and restore the normal histological structure compared to MTX alone. In conclusion, paeonol has a protective effect against MTX-induced cardiac toxicity through inhibiting oxidative and nitrosative stress and suppressing the TLR4/NF-κB/TNF-α/IL-6 inflammatory pathway, as well as causing an associated reduction in the proapoptotic marker, caspase 3.

Anticonvulsant and Neuroprotective Effects of Paeonol in Epileptic Rats.

Paeonol is the main active compound in the root bark extract of the peony tree, and it has antioxidative and anti-inflammatory effects. Recent studies have reported the neuroprotective effects of paeonol including its capacity in improving impaired memory. However, the effect of paeonol on epilepsy is yet to be demystified. We aimed to investigate the therapeutic effect of paeonol in epilepsy and its relationship with oxidative stress damage and neuronal loss in the rat brain to reveal the underlying mechanisms of epileptic seizures. A rat model for chronic epilepsy was established, and the seizure scores of the rats in different groups were recorded. The seizure duration and the seizure onset latency were used to evaluate the anticonvulsant effects of paeonol. Terminal deoxynucleotidyl transferase dUTP nick end-labeling staining, Nissl staining and H/E staining were used to evaluate the effects of paeonol on neuronal loss and apoptosis in epileptic rats. The colorimetric assessment of malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, catalase activity and total antioxidant capacity of paeonol were used in assessing paeonol's effect on oxidative stress in epileptic rats. Evaluation of Caspase-3 mRNA and protein expression levels were determined using western blot and quantitative real-time (RT-q)PCR. In this study, we found that paeonol reduced the seizure scores of epileptic rats and attenuated the duration and onset latency of seizures. Paeonol can also increase the activities of total antioxidant capacity, SOD and catalase activity and reduce MDA content as well. This suggests that paeonol can improve the level of oxidative stress in rats. More significantly, paeonol can improve neuronal loss and apoptosis in epileptic rats. These results indicate that paeonol has anticonvulsant and neuroprotective effects in epileptic rats. This effect may be caused by reducing oxidative stress.

Paeonol ameliorates monosodium urate-induced arthritis in rats through inhibiting nuclear factor-κB-mediated proinflammatory cytokine production.

Moutan Cortex has been widely used to treat various types of arthritis in traditional Chinese medicine. Paeonol is isolated as an active ingredient from Moutan Cortex. However, the effect and potential mechanism of paeonol on gouty arthritis have not been evaluated. In this study, rats were treated intragastrically with paeonol for consecutive 7 days. On Day 5, rats were intra-articularly injected with monosodium urate (MSU) crystals in the ankle joints to induce MSU-induced arthritis (MIA). Paw volume was detected at various time points. Gait score was measured at 24 hr after MSU crystal injection. Ankle joints were collected for evaluation of histological score and expression of proinflammatory cytokines using hematoxylin and eosin staining and immunohistochemistry staining, respectively. Nuclear level of nuclear factor (NF)-κBp65 in synovial tissues was analyzed by western blot assay. NF-κB DNA-binding activity was measured by enzyme linked immunosorbent assay. Paeonol markedly lowered the paw volume, gait score, and histological score in MIA rats. Mechanistically, paeonol markedly reduced the expression of TNF-α, IL-1ß, and IL-6 in synovial tissues of MIA rats. In addition, the elevated level of p65 in nucleus and NF-κB DNA-binding activity in synovial tissues of MIA rats were reduced significantly by paeonol treatment. These findings suggest that paeonol exerts anti-inflammatory effect in MIA rats through inhibiting expression of proinflammatory cytokines and NF-κB activation.

Neutrophil extracellular traps in acrolein promoted hepatic ischemia reperfusion injury: Therapeutic potential of NOX2 and p38MAPK inhibitors.

Neutrophil is a significant contributor to ischemia reperfusion (IR) induced liver tissue damage. However, the exact role of neutrophils in IR induced innate immune activation and liver damage is not quite clear. Our study sheds light on the role of chronic oxidative stress end products in worsening the IR inflammatory process by neutrophil recruitment and activation following liver surgery. We employed specific inhibitors for molecular targets-NOX2 (NADPH oxidase 2) and P38 MAPK (Mitogen activated protein kinase) signal to counteract neutrophil activation and neutrophil extracellular trap (NET) release induced liver damage in IR injury. We found that acrolein initiated neutrophil chemotaxis and induced NET release both in vitro and in vivo. Acrolein exposure caused NET induced nuclear and mitochondrial damage in HepG2 cells as well as aggravated the IR injury in rat liver. Pretreatment with F-apocynin and naringin, efficiently suppressed acrolein induced NET release in vitro. Notably, it suppressed the expression of inflammatory cytokines, P38MAPK-ERK activation, and apoptotic signals in rat liver exposed to acrolein and subjected to IR. Moreover, this combination effectively attenuated acrolein induced NET release and hepatic IR injury. In the current study we have shown that the acrolein accumulation in liver due to chronic stress, is responsible for neutrophil recruitment and its activation leading to NET induced liver damage during surgery. Our study shows that therapeutic targeting of NOX2 and P38MAPK signaling in patients with chronic hepatic disorders would improve post operative hepatic function and survival.

NOD2 promotes dopaminergic degeneration regulated by NADPH oxidase 2 in 6-hydroxydopamine model of Parkinson's disease.

BACKGROUND: In Parkinson's disease (PD), loss of striatal dopaminergic (DA) terminals and degeneration of DA neurons in the substantia nigra (SN) are associated with inflammation. Nucleotide-binding oligomerization domain-containing protein (NOD)2, one of the first discovered NOD-like receptors, plays an important role in inflammation. However, the role of NOD2 has not been elucidated in PD. METHODS: NOD2 mRNA and protein expression in the SN and the striatum of C57BL/6 mice treated with 6-hydroxydopamine (6-OHDA) was measured. We next investigated the potential contribution of the NOD2-dependent pathway to 6-OHDA-induced DA degeneration using NOD2-deficient (NOD2-/-) mice. Assays examining DA degeneration and inflammation include HPLC, Western blot, immunohistochemistry, TUNEL staining, and cytometric bead array. To further explore a possible link between NADPH oxidase 2 (NOX2) and NOD2 signaling in PD, microglia were transfected with shRNA specific to NOX2 in vitro and apocynin were given to mice subjected to 6-OHDA and muramyl dipeptide (MDP) striatal injection. RESULTS: The expression of NOD2 was upregulated in an experimental PD model induced by the neurotoxin 6-OHDA. NOD2 deficiency resulted in a protective effect against 6-OHDA-induced DA degeneration and neuronal death, which was associated with the attenuated inflammatory response. Moreover, silencing of NOX2 in microglia suppressed the expression of NOD2 and the inflammatory response induced by 6-OHDA and attenuated the toxicity of conditioned medium from 6-OHDA or MDP-stimulated microglia to neuronal cells. Furthermore, apocynin treatment inhibited NOD2 upregulation and DA degeneration in the SN of WT mice induced by 6-OHDA and MDP. CONCLUSION: This study provides the direct evidence that NOD2 is related to 6-OHDA-induced DA degeneration through NOX2-mediated oxidative stress, indicating NOD2 is a novel innate immune signaling molecule participating in PD inflammatory response.

Targeting the mitochondrial pyruvate carrier attenuates fibrosis in a mouse model of nonalcoholic steatohepatitis.

Diseases of the liver related to metabolic syndrome have emerged as the most common and undertreated hepatic ailments. The cause of nonalcoholic fatty liver disease is the aberrant accumulation of lipid in hepatocytes, though the mechanisms whereby this leads to hepatocyte dysfunction, death, and hepatic fibrosis are still unclear. Insulin-sensitizing thiazolidinediones have shown efficacy in treating nonalcoholic steatohepatitis (NASH), but their widespread use is constrained by dose-limiting side effects thought to be due to activation of the peroxisome proliferator-activated receptor γ. We sought to determine whether a next-generation thiazolidinedione with markedly diminished ability to activate peroxisome proliferator-activated receptor γ (MSDC-0602) would retain its efficacy for treating NASH in a rodent model. We also determined whether some or all of these beneficial effects would be mediated through an inhibitory interaction with the mitochondrial pyruvate carrier 2 (MPC2), which was recently identified as a mitochondrial binding site for thiazolidinediones, including MSDC-0602. We found that MSDC-0602 prevented and reversed liver fibrosis and suppressed expression of markers of stellate cell activation in livers of mice fed a diet rich in trans-fatty acids, fructose, and cholesterol. Moreover, mice with liver-specific deletion of MPC2 were protected from development of NASH on this diet. Finally, MSDC-0602 directly reduced hepatic stellate cell activation in vitro, and MSDC-0602 treatment or hepatocyte MPC2 deletion also limited stellate cell activation indirectly by affecting secretion of exosomes from hepatocytes. CONCLUSION: Collectively, these data demonstrate the effectiveness of MSDC-0602 for attenuating NASH in a rodent model and suggest that targeting hepatic MPC2 may be an effective strategy for pharmacologic development. (Hepatology 2017;65:1543-1556).

Non-conventional rottlerin anticancer properties.

In the past few years, we focused the interest on rottlerin, an old/new natural substance that, over the time, has revealed a number of cellular and molecular targets, all potentially implicated in the fight against cancer. Past and recent literature well demonstrated that rottlerin is an inhibitor of enzymes, transcription factors and signaling molecules that control cancer cell life and death. Although the rottlerin anticancer activity has been mainly ascribed to apoptosis and/or autophagy induction, recent findings unveiled the existence of additional mechanisms of toxicity. The major novelties highlighted in this mini review are the ability to bind and inhibit key molecules, such as ERK and mTOR, directly, thus independently of upstream signaling cascades, and to cause a profound dysregulation of cap-dependent protein translation through the mTORC1/4EBP1/eIF4E axis and by inhibition of eIF2, an initiation factor of translation that is negatively regulated by endoplasmic reticulum (ER) stress. These last mechanisms, proved to be lethal in cancer cell lines derived from breast and skin, strongly enforce the potential of rottlerin as a promising natural lead compound for the development of novel therapeutic approaches.

Apocynin combined with drugs as coadjuvant could be employed to prevent and/or treat the chronic kidney disease.

A worldwide public health problem is chronic kidney disease (CKD) presenting alarming epidemiological data. It currently affects about 10% of the adult population worldwide and has a high mortality rate. It is now known that oxidative stress represents one of the most important mechanisms in its pathophysiology, from the early stages to the terminal phase. Oxidation increases inflammation and reduces the capacity of NO• to relax vascular smooth muscle, in part by decreasing bioavailability of tetrahydrobiopterin (BH4), leading to endothelial dysfunction and high blood pressure, and due to the limited effectiveness of existing treatments, new drugs are needed to prevent and/or treat these mechanisms. The aim of this study was to test apocynin in a 5/6 nephrectomy mouse model of CKD to investigate whether its known antioxidant effect can improve the disease outcome. This effect results from the inhibition of NADPH oxidase and consequently a reduced production of the superoxide anion ([Formula: see text]). Animals were divided into five groups: sham, 5/6 nephrectomy only, and 5/6 nephrectomy followed by treatment with captopril, losartan or apocynin. The parameters evaluated were blood pressure and markers of oxidative stress ([Formula: see text]) and endothelial function (BH4). There were significantly lower levels of [Formula: see text] and a greater availability of serum BH4 in the apocynin-treated animals versus the control group and the two other drug treatments. The present findings suggest that apocynin in conjunction with a coadjuvant for modulating blood pressure may be useful for controlling the progression of CRF.