Isovitexin (Saponaretin)

Isovitexin is a flavonoid isolated from rice hulls of Oryza sativa, possesses anti-inflammatory and anti-oxidant activities; Isovitexin acts like a JNK1/2 inhibitor and inhibits the activation of NF-κB.

Isovitexin protects against LPS-induced oxidative damage by suppressing intracellular ROS generation, and also attenuates the effect of H2O2 on cell viability. Isovitexin (0-100 μg/mL) with LPS (2 μg/mL) is not cytotoxic to RAW 264.7 cells, but 200 μg/mL Isovitexin shows significant cytotoxicity. Isovitexin (25, 50 μg/mL) inhibits LPS-induced increases in TNF-α, IL-6, iNOS, and COX-2 levels. Isovitexin (25, 50 μg/mL) also suppresses the IκBα phosphorylation and degradation in RAW 264.7 cells, and such an effect is consistent with that of JNK1/2 inhibitor[1].

Isovitexin (50 and 100 mg/kg, i.p.) causes less severe histopathological changes in the lung sections, and reduces inflammatory cell count in LPS-induced mice. Isovitexin (50 and 100 mg/kg, i.p.) protects against LPS-induced inflammation and oxidative stress in LPS-induced ALI mice by decreasing TNF-α and IL-6 production, ROS generation, and MPO and MDA content, increasing SOD and GSH levels and effectively inhibiting the protein expression of iNOS and COX-2[1]. Isovitexin (25, 50, 100 mg/kg) dose-dependently reduces the survival rate of LPS/D-gal induced hepatic injury in mice. Isovitexin also inhibits NF-κB activation and up-regulates Nrf2 and HO-1 induced by LPS/D-gal in mice[2].

[1]. Lv H, et al. Isovitexin Exerts Anti-Inflammatory and Anti-Oxidant Activities on Lipopolysaccharide-Induced Acute Lung Injury by Inhibiting MAPK and NF-κB and Activating HO-1/Nrf2 Pathways. Int J Biol Sci. 2016 Jan 1;12(1):72-86. [2]. Hu JJ, et al. Isovitexin alleviates liver injury induced by lipopolysaccharide/d-galactosamine by activating Nrf2 and inhibiting NF-κB activation. Microb Pathog. 2018 Mar 29;119:86-92.