Ligustrazine is also known as tetramethylpyrazine. Tetramethylpyrazine is a dihydropyrazine found in Ligusticum walliichi that exhibits neuromodulatory, antioxidative, cognition enhancing, nephroprotective, antifibrotic, anti-inflammatory, and anticancer chemotherapeutic activities. This compound also inhibits PDE10A2 and acts as an antagonist at adenosine 2A and 2B receptors. In vitro, tetramethylpyrazine promotes neural progenitor cell migration and increases PI3K, PKC, and ERK signaling. Tetramethylpyrazine also induces neuroblastoma differentiation by targeting Topoisomerase Iiβ (topoIIβ). In animal models of chronic alcoholic encephalopathy, Tetramethylpyrazine improves learning and memory. Additionally, this compound inhibits arsenic-induced production of ROS and prevents apoptosis and mitochondrial dysfunction in kidney cells. Tetramethylpyrazine also ameliorates oxidative injury induced by methotrexate. In vitro, this compound inhibits proliferation of hepatic stellate cells. In animal models of hepatocellular carcinoma, tetramethylpyrazine inhibits tumor development and growth and induces cell cycle arrest and apoptosis.