Skullcapflavone II, a flavonoid derived from Scutellaria baicalensis, has anti-inflammatory, anti-microbial activities. Skullcapflavone II regulates osteoclast differentiation, survival, and function. Skullcapflavone II exerts potent antimicrobial activity against M. aurum and M. bovis BCG[1][2].

Skullcapflavone II inhibits osteoclastogenesis with decreased activation of MAPKs, Src, and cAMP response element-binding protein (CREB), which have been known to be redox sensitive. Skullcapflavone II decreases reactive oxygen species by scavenging them or activating nuclear factor-erythroid 2-related factor 2 (Nrf2), and its effects were partially reversed by hydrogen peroxide cotreatment or Nrf2 deficiency[2].

Skullcapflavone II, a potential bradykinin antagonist, reduces the major pathophysiological features of allergic asthma, at least in part by acting on TGF-β1/Smad signaling pathways[3].

[1]. Solnier J, et al. Flavonoids as Novel Efflux Pump Inhibitors and Antimicrobials Against Both Environmental and Pathogenic Intracellular Mycobacterial Species. Molecules. 2020;25(3):734. Published 2020 Feb 7. [2]. Lee J, et al. Skullcapflavone II inhibits osteoclastogenesis by regulating reactive oxygen species and attenuates the survival and resorption function of osteoclasts by modulating integrin signaling. FASEB J. 2019;33(2):2026-2036. [3]. Jang HY, et al. Skullcapflavone II inhibits ovalbumin-induced airway inflammation in a mouse model of asthma [published correction appears in Int Immunopharmacol. 2013 Sep;17(1):154]. Int Immunopharmacol. 2012;12(4):666-674.