Carnosic acid is a diterpene found in Rosmarinus that exhibits antioxidative, anti-inflammatory, neuroprotective, cognition enhancing, and anticancer chemotherapeutic activities. Carnosic acid inhibits growth of colon adenocarcinoma cells and decreases tumor number in vivo by downregulating expression of Bcl-xl and cyclin D1 and inducing cell cycle arrest and apoptosis. Carnosic acid also induces autophagy and inhibits Akt/mTOR signaling in hepatoma cells. In animal models of Alzheimer’s disease, carnosic acid ameliorates amyloid β (Aβ)-induced spatial memory and learning deficits. In other animal models, this compound decreases isoproterenol-induced increases in troponin I, creatine kinase, lactate dehydrogenase, SGOT, and SGPT and upregulates activity of phase II enzymes. Additionally, carnosic acid decreases TNF-α-induced activation of ERK, JNK, and IKK and expression of mTOR, eIF4E, and IL-6 in vitro.