Magnolol is an active component isolated from Magnolia officinalis (Magnolia bark). Magnolia officinalis is a traditional Chinese medicine widely used in facilitating bowel movement and ameliorate abdominal fullness. The bark is stripped from the stems, branches, and roots of Magnolia tree, and which is highly aromatic and polyphenolic components containing magnolol and honokiol. In addition to purification of magnolol from Magnolia-bark, preparation of synthetic magnolol/honokiol, its analogues and derivatives has been well established. In the past decades, magnolol has been characterized as an anti-oxidant, anti-depressant, antiallergic, anti-cancer and anti-microbial agent.
Magnolia officinalis has been widely used in traditional Chinese medicine. Magnolol, an active component isolated from Magnolia officinalis, is known to be a cardiovascular protector since 1994. The multiplex mechanisms of magnolol on cardiovascular protection depends on cell types and dosages, and will be reviewed and discussed in this article. Magnolol under low and moderate dosage possesses the ability to protect heart from ischemic/reperfusion injury, reduces atherosclerotic change, protects endothelial cell against apoptosis and inhibits neutrophil-endothelial adhesion. The moderate to high concentration of magnolol mainly acts on smooth muscle cells and platelets. Magnolol induces apoptosis in vascular smooth muscle cells at moderate concentration and inhibits proliferation at moderate and high concentration. High concentration of magnolol also abrogates platelet activation, aggregation and thrombus formation. Magnolol also serves as an smooth muscle relaxant only upon the high concentration. Oral intake of magnolol to reach the therapeutic level for cardiovascular protection is applicable, thus makes magnolol an agent of great potential for preventing cardiovascular diseases in high-risk patients.