Fungal substances as modulators of NF-κB activation pathway

MCF7 breast cancer cell line, carrying a luciferase reporter gene under the control of nuclear factor kappa B (NF-kappa B)-responsive promoter, was established and used for the screening of fungal organic extracts for their ability to interfere with the NF-kappa B activation pathway. Twenty-eight crude fungal extracts, out of 242, were found to inhibit NF-kappa B reporter activity by more than 40%. Furthermore, positive extracts were used to evaluate their antiproliferative activity as well as their ability to influence the phosphorylation and degradation levels of I kappa Ba. Fungal extracts prepared from Marasmius oreades and Cyathus striatus showed significant inhibitory effects on the NF-kappa B activation pathway. Taken together, our results support the notion of the presence of novel activities that might be utilized as cancer therapeutics.