A study of oxidative stress and pulmonary damage after silica instillation in rats and the effect of curcumin administration

Understanding the molecular basis of anti-fibrotic potential of intranasal curcumin and its association with mitochondrial homeostasis in silica-exposed mice

Silicosis is an occupational disease of the lungs brought in by repeated silica dust exposures. Inhalation of crystalline silica leads to persistent lung inflammation characterized by lung lesions due to granuloma formation. The specific molecular mechanism has not yet been identified, though. The Present study investigated the impact of silica-exposed lung fibrosis and probable molecular mechanisms. Here, Curcumin, derived from Curcuma longa shown to be an effective anti-inflammatory and anti-fibrotic molecule has been taken to investigate its therapeutic efficacy in silica-induced lung fibrosis. An experimental model of silicosis was established in mice where curcumin was administered an hour before intranasal silica exposure every alternate day for 35 days. Intranasal Curcumin treatment reduced silica-induced oxidative stress, inflammation marked by inflammatory cell recruitment, and prominent granuloma nodules along with aberrant collagen repair. Its protective benefits were confirmed by reduced MMP9 activities along with EMT markers (Vimentin and α-SMA). It has restored autophagy and suppressed the deposition of damaged mitochondria after silica exposure. Intranasal Curcumin also inhibited oxidative stress by boosting antioxidant enzyme activities and enhanced Nrf2-Keap1 expressions. Higher levels of PINK1, PARKIN, Cyt-c, P62/SQSTM, and damaged mitochondria in the silicosis group were significantly lowered after curcumin and dexamethasone treatments. Curcumin-induced autophagy resulted in reduced silica-induced mitochondria-dependent apoptosis. We report that intranasal curcumin treatment showed protective properties on pathological features prompted by silica particles, suggesting that the compound may constitute a promising strategy for the treatment of silicosis in the near future.

Protective effects and mechanism of curcumin in animal models of pulmonary fibrosis: a preclinical systematic review and meta-analysis

Introduction: At present, there is a lack of effective treatment for pulmonary fibrosis (PF), and a number of studies have confirmed that curcumin (CUR) has a good effect on PF. Research Qusetion: Is CUR effective in preclinical trials for PF and what is its mechanism of action? Methods: Animal reports of PF treated with CUR were searched from Pubmed, Embase, Web of Science and Cochrane Library from 1 January 2000 to 19 April 2023 to compare CUR treatment of PF with a no-intervention model group. A previous registration (nsply registration number: INPLASY202360084) of this review protocol was undertaken. Results: The meta-analysis included 27 publications and 29 studies involving 396 animals. CUR significantly improved the degree of fibrosis, levels of inflammation, and oxidative imbalances in lung tissue in animal models of PF. In terms fibrosis, such as HYP content (SMD = -4.96; 95% CI = -6.05 to -3.87; p = 0.000).In terms of inflammatory indicators, such as MPO activity (SMD = -2.12; 95% CI = -4.93 to 0.69; p = 0.000). In terms of oxidation index, such as MDA (SMD = -5.63; 95% CI = -9.66 to -1.6; p = 0.000). Conclusion: CUR significantly improved the degree of fibrosis, levels of inflammation, and oxidative imbalances in lung tissue in animal models of PF. Due to the quantitative and qualitative limitations of current research, more high-quality studies are needed to verify the above conclusion.

Targeting Oxidative Stress as a Therapeutic Approach for Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease characterized by an abnormal reepithelialisation, an excessive tissue remodelling and a progressive fibrosis within the alveolar wall that are not due to infection or cancer. Oxidative stress has been proposed as a key molecular process in pulmonary fibrosis development and different components of the redox system are altered in the cellular actors participating in lung fibrosis. To this respect, several activators of the antioxidant machinery and inhibitors of the oxidant species and pathways have been assayed in preclinical in vitro and in vivo models and in different clinical trials. This review discusses the role of oxidative stress in the development and progression of IPF and its underlying mechanisms as well as the evidence of oxidative stress in human IPF. Finally, we analyze the mechanism of action, the efficacy and the current status of different drugs developed to inhibit the oxidative stress as anti-fibrotic therapy in IPF.

Biological therapies targeting the type 2 inflammatory pathway in severe asthma (Review)

Asthma is a variable chronic respiratory disease characterized by airway inflammation and hyperresponsiveness, bronchoconstriction, and mucus hypersecretion. While most patients with asthma achieve good control of the disease, 5-10% experience severe symptoms and recurrent exacerbation despite the maximal offered therapy with inhaled corticosteroids and long acting bronchodilators. In previous years, novel biological therapies have become available, and various asthma phenotypes that are characterized by specific biomarkers have been identified. Currently approved biological agents target inflammatory molecules of the type 2 inflammatory pathway, and are effective at decreasing the frequency of asthma attacks, controlling symptoms and decreasing use of systemic steroids. The present study reviewed the effectiveness and safety profile of the currently approved biological drugs and provided an overview of the assessment of patients with severe asthma who are potentially suitable for biological therapy, in order to help clinicians to select the most appropriate biological agent.