Overexpression of Inducible Nitric Oxide Synthase in Allergic and Nonallergic Nasal Polyp

The oxidant-antioxidant imbalance was involved in the pathogenesis of chronic rhinosinusitis with nasal polyps

Background

Although oxidative stress is involved in the pathophysiological process of chronic rhinosinusitis with nasal polyps (CRSwNP), the specific underlying mechanism is still unclear. Whether antioxidant therapy can treat CRSwNP needs further investigation.

Methods

Immunohistochemistry, immunofluorescence, western blotting and quantitative polymerase chain reaction (qPCR) analyses were performed to detect the distribution and expression of oxidants and antioxidants in nasal polyp tissues. qPCR revealed correlations between oxidase, antioxidant enzymes and inflammatory cytokine levels in CRSwNP patients. Human nasal epithelial cells (HNEpCs) and primary macrophages were cultured to track the cellular origin of oxidative stress in nasal polyps(NPs) and to determine whether crocin can reduce cellular inflammation by increasing the cellular antioxidant capacity.

Results

The expression of NOS2, NOX1, HO-1 and SOD2 was increased in nasal epithelial cells and macrophages derived from nasal polyp tissue. Oxidase levels were positively correlated with those of inflammatory cytokines (IL-5 and IL-6). Conversely, the levels of antioxidant enzymes were negatively correlated with those of IL-13 and IFN-γ. Crocin inhibited M1 and M2 macrophage polarization as well as the expression of NOS2 and NOX1 and improved the antioxidant capacity of M2 macrophages. Moreover, crocin enhanced the ability of antioxidants to reduce inflammation via the KEAP1/NRF2/HO-1 pathway in HNEpCs treated with SEB or LPS. Additionally, we observed the antioxidant and anti-inflammatory effects of crocin in nasal explants.

Conclusion

Oxidative stress plays an important role in the development of CRSwNP by promoting various types of inflammation. The oxidative stress of nasal polyps comes from epithelial cells and macrophages. Antioxidant therapy may be a promising strategy for treating CRSwNP.

Levels of nasal nitric oxide and nitric oxide synthase expression in chronic rhinosinusitis with nasal polyposis

KEY POINTS

CRSwNP patients had decreased nNO and increased SNOT-22, endoscopy, and CT scores. CRSwNP patients exhibited decreased nNO despite elevated iNOS and eNOS mRNA expression. The mechanism behind lowered nNO in CRSwNP may not be related to NOS expression.

Clinical Applications of Nasal Nitric Oxide in Allergic Rhinitis: A Review of the Literature

Allergic rhinitis, a common allergic disease affecting a significant number of individuals worldwide, is observed in 25% of children and 40% of adults, with its highest occurrence between the ages of 20 and 40. Its pathogenesis, like other allergic diseases, involves innate and adaptive immune responses, characterized by immunologic hypersensitivity to environmental substances. This response is mediated by type 2 immunity. Within type 2 allergic diseases, certain molecules have been identified as clinical biomarkers that contribute to diagnosis, prognosis, and therapy monitoring. Among these biomarkers, nitric oxide has shown to play a key role in various physiological and pathological processes, including neurotransmission, immunity, inflammation, regulation of mucus and cilia, inhibition of microorganisms, and tumor cell growth. Therefore, measurement of nasal nitric oxide has been proposed as an objective method for monitoring airway obstruction and inflammation in different settings (community, hospital, rehabilitation) and in various clinical conditions, including upper airways diseases of the nose and paranasal sinuses. The purpose of this review is to analyze the potential mechanisms contributing to the production of nasal nitric oxide in allergic rhinitis and other related health issues. Additionally, this review aims to identify potential implications for future research, treatment strategies, and long-term management of symptoms.

Two Pairs of 7,7'-Cyclolignan Enantiomers with Anti-Inflammatory Activities from Perilla frutescens

Perilla frutescens (L.) Britt. (Labiatae), a medicinal plant, has been widely used for the therapy of multiple diseases since about 1800 years ago. It has been demonstrated that the extracts of P. frutescens exert significant anti-inflammatory effects. In this research, two pairs of 7,7′-cyclolignan enantiomers, possessing a cyclobutane moiety, (+)/(−)-perfrancin [(+)/(−)-1] and (+)/(−)-magnosalin [(+)/(−)-2], were separated from P. frutescens leaves. The present study achieved the chiral separation and determined the absolute configuration of (±)-1 and (±)-2. Compounds (+)-1 and (−)-1 have notable anti-inflammatory effects by reducing the secretion of pro-inflammatory factors (NO, TNF-α and IL-6) and the expression of pro-inflammatory mediators (iNOS and COX-2). These findings indicate that cyclolignans are effective substances of P. frutescens with anti-inflammatory activity. The present study partially elucidates the mechanisms underlying the effects of P. frutescens.

Nasal Nitric Oxide in the Upper Airway Inflammatory Diseases

Exhaled nitric oxide (eNO) from the lower respiratory tract is used commonly in diagnosis and treatment monitoring of asthma patients. However, nasal nitric oxide (nNO) has not been widely used in patients with upper airway inflammatory diseases due to its lack of standardized measurement methods. Nasal nitric oxide is produced mainly by the paranasal sinus mucosa and partially by the nasal mucosa and increases with inflammation. Nasal nitric oxide not only locally supports the defensive mechanism of the upper respiratory tract, but also remotely controls pulmonary function by acting as an aerocrine. Nasal NO can be affected by various physiologic and pathologic factors of the upper respiratory tract. This article will review the origin of nNO, its function, various measurement methods, and difference in presentation among upper respiratory tract inflammatory diseases such as allergic rhinitis, upper respiratory tract infection, nasal polyp, rhinosinusitis, primary ciliary dyskinesia, cystic fibrosis, Young’s syndrome, diffuse panbronchiolitis, empty nose syndrome, and obstructive sleep apnea. Future studies should identify the mechanism of action of nNO in various upper respiratory tract inflammatory diseases and obtain highly reproducible normal values of nNO based on a standardized measurement method with a deeper understanding of factors affecting nNO. Then, nNO will be useful for more rapid and simpler diagnosis of various upper respiratory tract diseases and for monitoring their treatment.

Naringin regulates erectile dysfunction by abolition of apoptosis and inflammation through NOS/cGMP/PKG signalling pathway on exposure to Bisphenol-A in hypertensive rat model

This study investigated the effect of naringin (NRG) on extracellular metabolism of ATP through the NOS/cGMP/PKG signaling pathway induced by Nω-nitro-L-arginine methyl ester hydrochloride (_L-NAME) on exposure to Bisphenol-A (BPA) in penis. Fifty-six adult male albino rats were randomly distributed into eight (n = 7) groups. Group I: control animals, Group II was treated with 40 mg/kg _L-NAME, Group III was treated with 50 mg/kg BPA, Group IV was treated with 40 mg/kg _L-NAME +50 mg/kg BPA. Group V was administered with 40 mg/kg _L-NAME +80 mg/kg NRG. Group VI was administered with 50 mg/kg BPA + 80 mg/kg NRG. Group VII was administered with 40 mg/kg _L-NAME+50 mg/kg BPA + 80 mg/kg NRG. Lastly, group VIII was treated with 80 mg/kg NRG for 14 days. NRG prevented hypertension and erectile dysfunction by inhibiting the activities of angiotensin-converting enzymes, arginase, and phosphodiesterase-5¹ (PDE-5¹) with corresponding down-regulation of inflammatory markers including TNF-α and IL-B. Additionally, hypertensive erectile dysfunction was remarkably prevented by NRG as manifested by the declined activities of AChE, MAO-A and enzymes of ATP hydrolysis (ATPase, ADPase, AMPase and ADA) with resultant increase in NO level. Also, penile expression of antigen presenting cells, CD43 transcript, caspace-9 and tumor suppressor P53 proteins were repressed on treatment with NRG. This study validates the hypothesis that NRG may be a valuable remedy in abrogating penile inflammatory markers, apoptosis and enzymes of ATP-hydrolysis via NOS/cGMP/PKG signaling pathways in hypertensive rat model on exposure to environmental toxicant.