Effects of curcumin on arginase enzyme activity, ornithine and nitric oxide levels in experimental breast cancer model

Abstract

Breast cancer accounts for almost 30% of all cancer types, making it the most common type of tumor among women in the world. Arginase, an essential enzyme of the urea cycle, leads to the formation of urea and ornithine from L-arginine using the same substrate as nitric oxide synthase (NOS). Arginase has been reported to be higher in cancer patients and can be used as a useful biomarker. In this study, we aimed to investigate the effects of curcumin, an anticarcinogenic agent, on arginase enzyme activity, ornithine, and nitric oxide (NO) levels in experimental breast cancer model in mice. 43 male Balb/c mice were used, and Erhlich acid tumor model was created in the study. Mice were divided into five groups as healthy control group, curcumin treatment before tumor formation, curcumin treatment after tumor formation and cancer control groups. 100 mg/kg curcumin were given orally. Serum and tissue arginase enzyme activities, NO levels and tissue ornithine levels were determined spectrophotometrically. Increased serum arginase activity decreased with curcumin treatment, but this difference was not statistically significant. On the other hand, decreased NO levels were increased with curcumin treatment. In tumor tissue, arginase activity and ornithine levels decreased significantly with curcumin treatment and tissue NO levels increased significantly with curcumin treatment. In our study, we show that curcumin may have a protective effect on the development of breast cancer by inhibiting arginase enzyme activity and ornithine levels, which are the precursors of polyamines, as well as inducing NO production via NOS. As a promising anticancer agent, the net effects of curcumin in this mechanism should be supported by more advanced studies and new parameters.