(±)-3-Carene is a bicyclic monoterpene found in a variety of plants, including Cannabis. It decreases phagocytosis by rat alveolar macrophages when used at a concentration of 0.5 &#181M and decreases their viability at a concentration of 5 &#181M. (±)-3-Carene increases the expression and activity of alkaline phosphatase in mouse osteoblastic MC3T3-E1 subclone 4 cells, indicating induction of osteoblastic differentiation. It also induces calcium formation and increases the expression of osteopontin and type I collagen, which are related to osteoblast mineralization. (±)-3-Carene induces bronchoconstriction in isolated guinea pig lungs when exposed at an air concentration of 3,000 mg/m3.