Early Preclinical Studies of Ergosterol Peroxide and\nBiological Evaluation of Its Derivatives

Ganoderma\nlucidum is a medicinal\nmushroom that produces various pharmacological compounds, including\ntriterpenoids. A major bioactive component of G. lucidum is ergosterol peroxide (EP), which is attributed to its anticancer\neffects. The current study focuses on the <i>in vitro</i> ADME (absorption, distribution, metabolism, and elimination), <i>in vivo</i> efficacy and toxicity of EP, and the synthesis of\nnew EP derivatives to improve aqueous solubility. It was found that\nEP is metabolically stable in liver microsomes and plasma. <i>In vivo</i> studies showed that EP inhibits tumor growth in\nmurine cancer models, and it is well tolerated by mice. The maximum\ntolerated dose was investigated in mice at escalating doses with a\ndefined maximum amount of 500 mg/kg, which indicated no signs of toxicity,\nconfirmed by plasma chemistry and analysis of harvested tissues. Complementary\norgan toxicity assays including cardio and hepatotoxicity assays of\nEP demonstrated no inhibitory effects. Next, a focused library of\nEP derivatives was developed to investigate the iterative addition\nof heteroatoms to improve the aqueous solubility properties of EP.\nSignificant solubility improvement was observed by the introduction\nof hydrogen bonding promoting groups, particularly the sulfate group.\nSuperior aqueous solubility properties are directly correlated with\nthe biological activity of the compound against triple-negative breast\ncancer cellular (TNBC) models. The EP derivatives maintain ample therapeutic\nindex at the tested concentrations, indicating they engage with the\nsame biological target(s) as the parental compound (EP). The combined\nstudies indicate that EP and its derivatives are selective TNBC cell\ndeath inducers, while sparing noncancerous tissue.