Optimization of Phenolic Compounds Extraction and Antioxidant Activity from Inonotus hispidus Using Ultrasound-Assisted Extraction Technology

The use of ultrasound-assisted extraction (UAE) of bioactive compounds has been increasing because it is a good alternative to the conventional extraction methods. UAE was used to maximize total polyphenol content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity, and ferric reducing antioxidant power (FRAP) of the mushroom Inonotus hispidus using response surface methodology (RSM). Firstly, the effect of 40% (v/v) ethanol and 80% (v/v) methanol on the TPC, DPPH scavenging capacity, and FRAP was evaluated. The ethanolic extracts showed a significantly higher (p < 0.0001) TPC, DPPH scavenging capacity, and FRAP than the methanolic extracts. The best condition to produce an extract with the higher TPC and antioxidant activity was achieved when using 40% (v/v) ethanol, a ratio of 75 mL/g, and an extraction time of 20 min. The chromatographic profile of the extract obtained in the optimized condition revealed that hispidin is the main polyphenol present in the extracts of I. hispidus, representing, together with hispidin-like compounds, the majority of the phenolic compounds (159.56 µg/g DW out of 219.01 µg/g DW). The model allowed us to optimize the conditions to maximize the extraction of phenolic compounds with antioxidant activity from I. hispidus, demonstrating its potential as a source of antioxidant compounds, with possible industrial, pharmaceutical, and food applications.

IL-4/IFN-γ inflammatory cytokine profile induces a deficient regulation of the IL-1β/IL-1RI/EP2/COX-2 pathway in nasal mucosa

BACKGROUND

We hypothesized that the peculiar mixed interleukin-4 (IL-4/Th2) and interferon gamma INF-γ (INF-γ/Th1) inflammatory milieu found in the airways of patients with aspirin-exacerbated respiratory disease (AERD) is responsible for the altered regulation of the IL-1β/IL-1RI-/EP₂/COX-2 autocrine loop also found in these patients. The objective of the study is to demonstrate that IL-4 and INF-γ cytokines, are capable of inducing in healthy nasal mucosa (NM) the dysregulation of the autocrine loop of COX reported in AERD.

SUBJECTS AND METHODS

Fibroblasts were obtained from NM (n = 8). To evaluate the role of IL-4 and IFN-γ on the autocrine loop, fibroblasts were incubated with or without IL-1β, in the presence or absence of IL-4 and/or IFN-γ for 48 h. After this period, the expression of EP₂, EP₃, EP₄, IL-1RI, COX-2 and mPGES-1 was measured by Western blot.

RESULTS

Stimulation of fibroblasts with IL-1β significantly increased the expression of EP₂, but had no effects on EP₃ and EP₄ expression Incubation with IL-4 or IFN-γ alone was not able to modify the expression of any of the components of the autocrine loop. In contrast, co-treatment with IL-4 and IFN-γ was able to significantly inhibit IL-1β-induced EP₂, IL-1RI, COX-2 and mPGES-1.

CONCLUSION

These results suggest that the mixed Th1/Th2 inflammatory pattern found in the airways of AERD patients might be responsible for the altered regulation of the COX pathway also reported in these asthma patients.

Altered expression and signalling of EP2 receptor in nasal polyps of AERD patients: role in inflammation and remodelling

BACKGROUND

Down-regulation of the E-prostanoid (EP)2 receptor has been reported in aspirin exacerbated respiratory disease (AERD). We aimed to evaluate the expression and activation of EP receptors in AERD and their role in prostaglandin (PG) E2 signalling.

METHODS

Samples were obtained from nasal mucosa of control subjects (NM-C, n=7) and from nasal polyps of AERD patients (NP-AERD, n=7). Expression of EP1-4 was assessed at baseline. Fibroblasts were stimulated with receptor agonists to measure cAMP levels, cell proliferation and granulocyte-macrophage colony-stimulating factor (GM-CSF) release.

RESULTS

NM-C and NP-AERD samples and fibroblasts expressed EP2, EP3 and EP4 at baseline. Lower expression of EP2 and higher expression of EP4 was observed in NP-AERD compared with NM-C. Stimulation with PGE2 and butaprost caused a higher increase in cAMP in NM-C than in NP-AERD. On the contrary, CAY10598 produced a higher production of cAMP in NP-AERD compared with NM-C. The anti-proliferative effect of PGE2 and butaprost was lower in NP-AERD than in NM-C fibroblasts. Similarly, the capacity of PGE2 and butaprost to inhibit GM-CSF release was lower in NP-AERD than in NM-C.

CONCLUSIONS

The altered expression of EP2 in AERD may contribute to reduce the capacity of PGE2 to mediate anti-proliferative and anti-inflammatory effects.

Altered expression and signalling of EP2 receptor in nasal polyps of AERD patients: role in inflammation and remodelling

BACKGROUND

Down-regulation of the E-prostanoid (EP)2 receptor has been reported in aspirin exacerbated respiratory disease (AERD). We aimed to evaluate the expression and activation of EP receptors in AERD and their role in prostaglandin (PG) E2 signalling.

METHODS

Samples were obtained from nasal mucosa of control subjects (NM-C, n=7) and from nasal polyps of AERD patients (NP-AERD, n=7). Expression of EP1-4 was assessed at baseline. Fibroblasts were stimulated with receptor agonists to measure cAMP levels, cell proliferation and granulocyte-macrophage colony-stimulating factor (GM-CSF) release.

RESULTS

NM-C and NP-AERD samples and fibroblasts expressed EP2, EP3 and EP4 at baseline. Lower expression of EP2 and higher expression of EP4 was observed in NP-AERD compared with NM-C. Stimulation with PGE2 and butaprost caused a higher increase in cAMP in NM-C than in NP-AERD. On the contrary, CAY10598 produced a higher production of cAMP in NP-AERD compared with NM-C. The anti-proliferative effect of PGE2 and butaprost was lower in NP-AERD than in NM-C fibroblasts. Similarly, the capacity of PGE2 and butaprost to inhibit GM-CSF release was lower in NP-AERD than in NM-C.

CONCLUSIONS

The altered expression of EP2 in AERD may contribute to reduce the capacity of PGE2 to mediate anti-proliferative and anti-inflammatory effects.

Low E-prostanoid 2 receptor levels and deficient induction of the IL-1β/IL-1 type I receptor/COX-2 pathway: Vicious circle in patients with aspirin-exacerbated respiratory disease

BACKGROUND

We hypothesized that the 2 reported alterations in aspirin-exacerbated respiratory disease (AERD), reduced expression/production of COX-2/prostaglandin (PG) E2 and diminished expression of E-prostanoid (EP) 2 receptor, are closely linked.

OBJECTIVE

We sought to determine the mechanisms involved in the altered regulation of the COX pathway in patients with AERD.

METHODS

Fibroblasts were obtained from nasal mucosa; samples of control subjects (NM-C, n = 8) and from nasal polyps from patients with aspirin-exacerbated respiratory disease (NP-AERD, n = 8). Expression of the autocrine loop components regulating PGE2 production and signaling, namely IL-1 type I receptor (IL-1RI), COX-2, microsomal prostaglandin E synthase 1 (mPGES-1), and EP receptors, was assessed at baseline and after stimulation with IL-1β, PGE2, and specific EP receptor agonists.

RESULTS

Compared with NM-C fibroblasts, basal expression levels of IL-1RI and EP2 receptor were lower in NP-AERD fibroblasts. IL-1β-induced IL-1RI, COX-2, and mPGES-1 expression levels were also lower in these cells. Levels of IL-1RI positively correlated with COX-2 and mPGES-1 expression in both NM-C and NP-AERD fibroblasts. Incubation with either exogenous PGE2 or selective EP2 agonist significantly increased expression of IL-1RI in NM-C fibroblasts and had hardly any effect on NP-AERD fibroblasts. Alterations in IL-1RI, COX-2, and mPGES-1 expression that were found in NP-AERD fibroblasts were corrected when EP2 receptor expression was normalized by transfection of NP-AERD fibroblasts.

CONCLUSION

Altered expression of EP2 in patients with AERD contributes to deficient induction of IL-1RI, reducing the capacity of IL-1β to increase COX-2 and mPGES-1 expression, which results in low PGE2 production. This impairment in the generation of PGE2 subsequently reduces its ability to induce IL-1RI.

Prostaglandin E2 receptors in asthma and in chronic rhinosinusitis/nasal polyps with and without aspirin hypersensitivity

Chronic rhinosinusitis with nasal polyps (CRSwNP) and asthma frequently coexist and are always present in patients with aspirin exacerbated respiratory disease (AERD). Although the pathogenic mechanisms of this condition are still unknown, AERD may be due, at least in part, to an imbalance in eicosanoid metabolism (increased production of cysteinyl leukotrienes (CysLTs) and reduced biosynthesis of prostaglandin (PG) E2), possibly increasing and perpetuating the process of inflammation. PGE2 results from the metabolism of arachidonic acid (AA) by cyclooxygenase (COX) enzymes, and seems to play a central role in homeostasis maintenance and inflammatory response modulation in airways. Therefore, the abnormal regulation of PGE2 could contribute to the exacerbated processes observed in AERD. PGE2 exerts its actions through four G-protein-coupled receptors designated E-prostanoid (EP) receptors EP1, EP2, EP3, and EP4. Altered PGE2 production as well as differential EP receptor expression has been reported in both upper and lower airways of patients with AERD. Since the heterogeneity of these receptors is the key for the multiple biological effects of PGE2 this review focuses on the studies available to elucidate the importance of these receptors in inflammatory airway diseases.