**4.2 Anti-inflammatory effects of Resveratrol**

Resveratrol is a polyphenolic compound found in peanuts, carob molasses, blueberries, grapes, and red wine [102, 103]. It has been reported in various studies that it stimulates nitric oxide synthesis while suppressing oxidative stress [104–109]. Besides, studies have reported that resveratrol plays a protective role in major respiratory diseases such as ARDS, COPD, and allergic inflammation [110]. These diseases increase the susceptibility to Covid-19 disease and the probability of death increases [22]. In vitro studies have reported that resveratrol has anti-inflammatory and antioxidant properties in COPD patients. It has been reported that resveratrol reduces glutathione (GSH) consumption by activating the nuclear factor (erythroid derivative 2) derivative (Nrf2) pathway, which is a redox-sensitive transcription factor [111]. In other studies, resveratrol has also been reported to inhibit COPD-associated inflammatory mediators such as TNF-α, IL-6, IL-8, MCP-1, and granulocyte-macrophage colony-stimulating factor (GM-CSF) and reduced nuclear NF-κB expression [112–114]. In another study conducted using cigarette smoke, resveratrol reduced the histological damage of the lung, lowered pro-inflammatory protein levels TNF-α, IL-17, IL-6, and transforming growth factor TGF-beta, and prevented airway remodeling, and It has been reported to reduce excessive mucus secretion [115]. Resveratrol SIRT1 and PGC-1 have also been reported to reduce inflammation and restructuring of small airways in lung tissue by increasing α expression [116]. Consistent with in vitro data, resveratrol treatment has been reported to increase superoxide dismutase (SOD) and catalase (CAT) activities and glutathione (GSH) levels, and in addition to preventing NF-κB translocation and binding activity to the nucleus [111]. In-vivo

### *Can Polyphenols be Used as Anti-Inflammatory Agents against Covid-19… DOI: http://dx.doi.org/10.5772/intechopen.98684*

studies conducted over the past few years have shown that resveratrol can effectively control asthma in mouse models [110]. Resveratrol exerts its anti-inflammatory effect by suppressing the passage of inflammatory cells, especially eosinophils, to bronchoalveolar lavage fluid (BALF) and lung tissue by suppressing AHR [101]. Total immunoglobulin E (IgE) and ovalbumin (OVA) specific IgE levels were reported to be decreased in the OVA-induced asthma model and decreased levels of TNF-, IL-4 and IL-5 cytokines [110]. In another study, it was reported that TGF and TGF-B1/ phosphorylated Smad 2/3 receptor expression levels decreased significantly as a result of treatment with resveratrol [117, 118]. Currently, there is still no effective treatment for COPD, but resveratrol has been added to existing treatment protocols for its beneficial effect against lung damage and its beneficial effect in reducing inflammation through several possible molecular mechanisms. Resveratrol reduces myeloperoxidase protein expression and activity in the treatment of structural changes in the lung, reducing pulmonary edema, improving lung functions, decreasing neutrophil infiltration. Regarding cytokines, resveratrol IL-1ß, IL-18, IL-6; It has been reported that COX-2 and macrophage inflammatory protein-1 (MIP-1) significantly modulate BALF and systemic TNF-α. Considering the findings obtained in these studies, it is thought that resveratrol can prevent inflammation caused by Covid-19 as in other respiratory system diseases.
