The Antioxidant and Anti-Inflammatory Effects of Flavonoids from Propolis via Nrf2 and NF-κB Pathways

Abstract

Accumulating evidence shows that oxidative stress and inflammation contribute to the development of cardiovascular disease. It has been suggested that propolis possesses antioxidant and anti-inflammatory activities. In this study, the antioxidant and anti-inflammatory effects of the main flavonoids of propolis (chrysin, pinocembrin, galangin, and pinobanksin) and propolis extract were researched. The results showed that the cellular ROS (Reactive oxygen species) levels, antioxidant enzymes, Nrf2 (Nuclear factor erythroid 2-related factor 2) nuclear translocation, and the expression of NQO1 (NAD(P)H:quinone oxidoreductase 1) and HO-1 (heme oxygenase 1) were regulated by different concentrations of individual flavonoids and propolis extract, which showed good antioxidant and pro-oxidant effects. For example, ROS levels were decreased; SOD and CAT activities were increased; and the expression of HO-1 protein was increased by chrysin. The results demonstrated that NO (Nitric Oxide), NOS (Nitric Oxide Synthase), and the activation of the NF-κB signaling pathway were inhibited in a dose-dependent manner by different concentrations of individual flavonoids and propolis extract. Moreover, the results revealed that the phytochemicals presented antioxidant effects at lower concentrations but pro-oxidant effects and stronger anti-inflammatory effects at higher concentrations. To maintain the balance of antioxidant and anti-inflammatory effects, it is possible that phytochemicals activate the Nrf2 pathway and inhibited the NF-κB (Nuclear factor kappa B) pathway.

Citrus junos Tanaka Peel Extract Ameliorates HDM-Induced Lung Inflammation and Immune Responses In Vivo

“…Reactive oxygen species (ROS) are associated with NF-κB signaling and play a critical role in the anti-inflammatory effects of several functional foods rich in isoflavonoids [ 38 , 39 , 40 ]. Narirutin, a key flavonoid of Citrus junos , was reported to have an anti-inflammatory effect on lipopolysaccharide-stimulated macrophages by lowering IL-β, TNF-α, nitric oxide (NO), and prostaglandin E2 through the inhibition of NF-κB and MAPKs activation in vitro [ 41 ].…”

The protective activity of natural flavonoids against osteoarthritis by targeting NF-κB signaling pathway

“…It has been reported that apigenin and genistein may interact with the IκBα/NF-κB complex with the binding energies of −34.0 and −31.7 kJ/mol, respectively, leading to decreased IκBα and p65 phosphorylation, attenuated NF-κB nuclear translocation, and inactivated NF-κB signaling ( 146 ). Similarly, quercetin, chrysin, pinocembrin, galangin, pinobanksin, and nobiletin can suppress NF-κB signaling by inhibiting IκBα and p65 phosphorylation and suppressing NF-κB nuclear translocation ( 147 – 149 ). Both cajanin (3’,5-dihydroxy-7-methoxy-isoflavone) and prunetin (5-hydroxy-7-methoxy-isoflavone) may inhibit IκBα and p65 phosphorylation.…”

LC‐ESI‐MS/MS Chemical Characterization, Antioxidant and Antidiabetic Properties of Propolis Extracted with Organic Solvents from Eastern Anatolia Region

“…Studies on propolis have shown that flavonoids belonging to propolis exhibited strong antioxidant properties [3,20,23–27] . It has been proven that these flavonoids inhibit the oxidation of lipoproteins by inhibiting copper ions [28] .…”