(±) -Shikonin

(±) -Shikonin, a potent and specific Pyruvate kinase M2 (PKM2) inhibitor, is a major component of zicao (purple gromwell, the dried root of Lithospermum erythrorhizon), a Chinese herbal medicine with various biological activities. It is also an inhibitor of TMEM16A chloride channel activity using cell-based fluorescent-quenching assay. Shikonin exerts an anti-inflammatory effect by inhibiting tumor necrosis factor-α (TNF-α) and prevents activation of nuclear factor-κB (NF-κB) pathway via proteasome inhibition.