baicalein

Baicalein is a natural flavone whose chemical name is 5,6,7-trihydroxyflavone. It occurs in plants such as Scutellaria baicalensis (Chinese skullcap) and is the aglycone form of baicalin, a major flavone glycoside found in the same plants. Baicalein belongs to the flavone subclass of flavonoids and is commonly studied for its biological activity as part of traditional herbal preparations and isolated compounds.

In vitro and in vivo research has reported a range of biological effects. Baicalein exhibits anti-inflammatory activity, including inhibition of inducible nitric oxide synthase and cyclooxygenase-2, and modulation of signaling pathways related to inflammation. It also shows antioxidant properties by scavenging reactive oxygen species and supporting cellular antioxidant defenses. In cancer models, baicalein can inhibit cell proliferation and induce apoptosis through multiple pathways, with effects on signaling cascades such as MAPK and p53. Neuroprotective effects have been observed in models of ischemic injury and neurodegenerative conditions. Antiviral activity against several RNA viruses has been reported in cell culture studies, though clinical relevance remains to be established.

Pharmacokinetics of baicalein indicates poor oral bioavailability in part due to limited solubility and extensive first-pass metabolism, with rapid formation of glucuronide and sulfate conjugates. Tissue distribution includes the liver and kidneys, and research has explored formulation approaches such as nanoencapsulation or complexation to improve solubility and delivery.

Baicalein is not approved as a drug and evidence for clinical efficacy is limited to preclinical and ethnomedicinal use. Safety data are modest, and potential interactions with drug-metabolizing enzymes warrant consideration in combination therapies.