Anti-Inflammatory, Antioxidative, and Nitric Oxide-Scavenging Activities of a Quercetin Nanosuspension with Polyethylene Glycol in LPS-Induced RAW 264.7 Macrophages

Abstract

Quercetin (Qu) is a dietary antioxidant and a member of flavonoids in the plant polyphenol family. Qu has a high ability to scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) molecules; hence, exhibiting beneficial effects in preventing obesity, diabetes, cancer, cardiovascular diseases, and inflammation. However, quercetin has low bioavailability due to poor water solubility, low absorption, and rapid excretion from the body. To address these issues, the usage of Qu nanosuspensions can improve physical stability, solubility, and pharmacokinetics. Therefore, we developed a Qu and polyethylene glycol nanosuspension (Qu-PEG NS) and confirmed its interaction by Fourier transform infrared analysis. Qu-PEG NS did not show cytotoxicity to HaCaT and RAW 264.7 cells. Furthermore, Qu-PEG NS effectively reduced the nitrogen oxide (NO) production in lipopolysaccharide (LPS)-induced inflammatory RAW 264.7 cells. Additionally, Qu-PEG NS effectively lowered the levels of COX-2, NF-κB p65, and IL-1β in the LPS-induced inflammatory RAW 264.7 cells. Specifically, Qu-PEG NS exhibited anti-inflammatory properties by scavenging the ROS and RNS and mediated the inhibition of NF-κB signaling pathways. In addition, Qu-PEG NS had a high antioxidant effect and antibacterial activity against Escherichia coli and Bacillus cereus. Therefore, the developed novel nanosuspension showed comparable antioxidant, anti-inflammatory, and antibacterial functions and may also improve solubility and physical stability compared to raw quercetin.

Morin hydrate suppresses lipoteichoic acid-induced oxidative stress-mediated inflammatory events in macrophages via augmenting Nrf2/HO-1 and antioxidant defense molecules

“…LTA exposure induces adhesion, growth, and proliferation, promoting cell maturation and widespread distribution. 29 This morphological response confirms the ability of LTA to modify the cells and elicit an inflammatory reaction which is consistent with the previous study. 21 The viability assessment, combined with the examination of cell morphology in Figure 2(c) (i)-(vii), demonstrates that MH concentrations up to 40 µM do not induce cytotoxic effects on macrophages.…”

“…This finding is consistent with precious studies reporting favorable DPPH and ABTS antioxidant activity of other flavonoid compounds. 29,30 NO is a highly reactive free radical and a critical sencondary messenger involved in mediating inflammatory responses. 30,31 However, treatment with MH alongside LTA resulted in reduced NO production in RAW264.7 cells.…”

Tart Cherry (Prunus cerasus L.) Pit Extracts Protect Human Skin Cells against Oxidative Stress: Unlocking Sustainable Uses for Food Industry Byproducts

“…Apigenin (Figure 3I) and quercetin (Figure 3J) significantly decreased cell viability at 100 µM (p < 0.001). Consistent with our results, others have shown that these compounds do not affect the viability of skin cells [52][53][54][55][56][57][58]. Based on our metabolomic results shown in Table 2, the concentrations of these compounds in the highest doses of CP extracts used in the cell viability assays are less than 500 nM, which is at least 50-fold lower than the dosages of the pure polyphenols tested (Figure 3E-J).…”

Antiaging effects of dietary supplements and natural products

“…The anti-inflammatory and antiallergic properties of quercetin have been proven to treat respiratory and food allergies ( Escribano-Ferrer et al, 2019 ). It has been shown to effectively lower the levels of inflammatory cytokines in the lipopolysaccharide (LPS)-induced inflammatory RAW 264.7 cells ( Kang et al, 2022 ) and rat intestinal epithelial (IEC-6) cells via suppressing NF-κB activation in vitro ( Cai et al, 2021 ). Quercetin administration in diabetic rats also effectively decreases the levels of serum C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), blood glucose, and inflammatory cytokines by enhancing AKT phosphorylation, inhibiting nuclear factor-kappa (NF-κB) levels, and reducing inflammation-induced hyperlipidemia ( Hosseini et al, 2021 ).…”