WINSTON-SALEM, N.C.—According to a study published Carcinogenesis, curcumin may exhibit organ-specific effects to enhance reactive oxygen species formation in the damaged lung epithelium of smokers and ex-smokers (2009; DOI:10.1093/carcin/bgp082). Curcumin's chemopreventive activity was tested in a transgenic mouse model of lung cancer that expresses the human Ki-rasG12C allele in a doxycycline (DOX) inducible and lung-specific manner. The effects of curcumin were compared to the lung tumor promoter, butylated hydroxytoluene (BHT) and the lung cancer chemopreventive agent, sulindac. Treatment of DOX-induced mice with dietary curcumin increased tumor multiplicity (36.3±0.9 vs. 24.3±0.2) and progression to later stage lesions, results which were similar to animals that were co-treated with DOX/BHT. Microscopic examination showed that the percentage of lung lesions that were adenomas and adenocarcinomas increased to 66 percent in DOX/BHT, 66 percent in DOX/curcumin and 49 percent in DOX/BHT/curcumin treated groups relative to DOX only treated mice (19 percent). Immunohistochemical analysis also showed increased evidence of inflammation in DOX/BHT, DOX/curcumin and DOX/BHT/curcumin mice relative to DOX only treated mice. In contrast, co-treatment of DOX/BHT mice with 80 ppm of sulindac inhibited the progression of lung lesions and reduced the inflammation. Lung tissue from DOX/curcumin treated mice demonstrated a significant increase (33 percent; P=0.01) in oxidative damage, as assessed by the levels of carbonyl protein formation, relative to DOX-treated control mice after one week on the curcumin diet. Researchers noted ongoing clinical trials may need to exclude smokers and ex-smokers in chemopreventive trials of curcumin.