The Shaggy Inc Cap medicinal mushroom, Coprinus comatus (O.F.Mull.: Fr.) Pers. (Agaricomycetideae) substances interfere with H2O2 induction of the NF-kappaB pathway through inhibition of Ikappaalpha phosphorylation in MCF7 breast cancer cells.

Breast cancer is the most commonly diagnosed cancer among women. Currently, there is no effective therapy for malignant estrogen-independent breast cancer. In our study, we used hydrogen peroxide, a well-known strong oxidative reagent capable of activating the nuclear factor kappa B (NF-kappaB) transcription factor. The IC50 value of the culinary-medicinal Shaggy Inc Cap mushroom Coprinus comatus culture liquid crude extract on MCF7 cell viability was found to be as low as 76 microg/mL, and the IC50 value of C. comatus ethyl acetate extract was only 32 microg/ mL. Our results also showed that both extracts significantly affected IkappaBalpha phosphorylation in a dose-dependent manner. The effect of ethyl acetate extract was comparable to the effect of curcumin, a known NF-kappaB pathway inhibitor, and seemed to be the most active inhibitor of H2O2-dependent IkappaBalpha phosphorylation. In addition, the data obtained showed that only ethyl acetate extract inhibited the activity of IKK complex, at close to 90% as compared to the control of the untreated sample. These results suggest that C. comatus contains potent compounds capable of inhibiting NF-kappaB function and also possibly acts as an antitumor agent.