Curcumin is a major component of the spice turmeric which has been used in traditional Chinese and Indian herbal medicine to treat a wide range of conditions. This history demonstrates that curcumin is not toxic and may indeed have value in the treatment of human diseases. Our long-term goal is to use curcumin to treat lung injury/fibrosis in human patients. The value of work in this area is strongly supported by observations that curcumin protects rodents against lung injury/fibrosis induced by a variety of agents. A major drawback to the use of curcumin as a treatment for human diseases is its poor absorption and rapid metabolism following oral administration. Experiments on novel routes of administration of curcumin to mice will address this problem. While curcumin affects the activity of a wide variety of enzymes and signaling molecules, the cellular mechanism through which it provides protection against lung injury/fibrosis has not been determined. Our studies on the mechanism of curcumin will take advantage of our recent work on another protective agent, CSD peptide, which has beneficial effects on at least five cell types. In mice in which lung injury/fibrosis is induced using bleomycin, the CSD peptide inhibits the apoptosis of alveolar epithelial cells, the migration of neutrophils, monocytes, and fibrocytes into damaged lung tissue, and the overexpression of collagen by lung myofibroblasts. Therefore, we will determine which of these target cell types is also affected by curcumin treatment. In summary, this application will test the linked hypotheses that alternate approaches to delivering curcumin in vivo will lead to enhanced levels of circulating curcumin resulting in more robust protection against lung injury/fibrosis and that the beneficial effects of curcumin will result in changes in the behavior of one or more of several cell types already shown to be targets for therapeutic treatments that inhibit lung injury/fibrosis. Specifically, we will: 1) Determine whether alternative methods of delivering curcumin result in higher levels of circulating curcumin and in greater beneficial effects in inhibiting the progression of lung injury/fibrosis than are provided by the traditional oral administration in curcumin chow. 2) Determine whether the beneficial effects of curcumin on the progression of bleomycin-induced lung injury/fibrosis involve changes in the behavior of alveolar epithelial cells, neutrophils, monocytes, fibrocytes, and/or myofibroblasts. The successful completion of these studies will bring us much closer to performing clinical trials using curcumin as a treatment for lung injury/fibrosis in human patients. PUBLIC HEALTH RELEVANCE: Mainstream medicine currently provides no effective treatments for lung diseases in which the injured tissue becomes stiff or fibrotic. Curcumin, derived from the spice turmeric, is a treatment from alternative medicine that blocks these diseases in rodent models. The proposed experiments will reveal more efficient ways to increase the level of curcumin in the bodies of treated animals and will indicate which of the several cell types in the lung are beneficially affected by curcumin, thereby bringing us a step closer to testing curcumin as a treatment for lung injury/fibrosis in human patients.