Thymoquinone (Tq) protects necroptosis induced by autophagy/mitophagy-dependent oxidative stress in human bronchial epithelial cells exposed to cigarette smoke extract (CSE)

Chronic obstructive pulmonary disease (COPD) is characterized by cigarette smoke-induced emphysema. Herein, we demonstrate protective effects of Thymoquinone (Tq), an active constituent from Nigella sativa, against cigarette smoke extract (CSE)-induced abnormalities in bronchial epithelial cells. Dose-dependent reduction in cell viability was observed in BEAS-2B cells when exposed to different CSE concentrations, which was significantly reversed by Tq evident by LDH release. Levels of SOD, CAT, G_R , GSH, and mitochondrial membrane ATPases were significantly reduced upon CSE exposure, an event, again, antagonized in presence of Tq. Similarly, Tq treatment significantly blocked CSE-induced 4HNE elevations. Further, Tq-improved mitochondrial dysfunction caused by CSE and significantly decreased autophagy/mitophagy markers like LC3II and p-Drp. Tq also reduced necroptosis markers such as p-MLKL, RIP-1, and RIP-3, by stabilizing PINK-1 levels. In summary, Tq possesses protective properties against human bronchial epithelial cell autophagy/mitophagy-dependent necroptosis caused by CSE, which warrants considerable attention for further preclinical evaluations. PRACTICAL APPLICATIONS: This study demonstrates Thymoquinone (Tq), a natural plant extract to possess protective properties against human bronchial epithelial cell autophagy/mitophagy-dependent necroptosis caused by cigarette smoke extract. The demonstrated efficacy of Tq will throw light for further preclinical evaluation of this molecule in CSE-mediated complications. A detailed in vivo research is recommended.

Thymoquinone attenuates IgE-mediated allergic response via pi3k-Akt-NFκB pathway and upregulation of the Nrf2-HO1 axis

IgE-dependent reactions mediate the majority of allergic diseases. This study explores the effects of thymoquinone (Tq) on IgE-mediated allergic response in activated mast cells, basophils, and neutrophils. Tq treatment resulted in a dose-dependent decrease in levels of TNF-α and IL-4 in activated RBL-2H3 cells. Tq inhibited the degranulation of these cells with an IC₅₀ value of 56.37 µM. Moreover, the compound suppressed basophil activation induced through FcεRI receptors with an IC₅₀ value of 45.76 µM in heparinized human whole blood. Likewise, neutrophil migration and elastase activity were dose-dependently reduced. While Tq decreased the phosphorylation of Akt and NFκB in activated RBL-2H3 cells, it increased nuclear Nrf2 and HO-1 antioxidant proteins. Our results indicate that Tq possesses demonstrable activity in cellular models of IgE-mediated allergic reactions. PRACTICAL APPLICATIONS: The current study sheds light on the mechanistic pathways of Tq on IgE-based response in activated mast cells, basophils, and neutrophils. The output of this preclinical in vitro study may be translated into better chemotherapeutic applications of Tq and its analogs in the treatment of allergic inflammation. However, a detailed investigation of in vivo models is recommended.