Molecular mechanism of emodin action: Transition from laxative ingredient to an antitumor agent

Abstract

Anthraquinones represent a large family of compounds having diverse biological properties. Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is a naturally occurring anthraquinone present in the roots and barks of numerous plants, molds, and lichens, and an active ingredient of various Chinese herbs. Earlier studies have documented mutagenic/genotoxic effects of emodin, mainly in bacterial system. Emodin, first assigned to be a specific inhibitor of the protein tyrosine kinase p65lck, has now a number of cellular targets interacting with it. Its inhibitory effect on mammalian cell cycle modulation in specific oncogene overexpressed cells formed the basis of using this compound as an anticancer agent. Identification of apoptosis as a mechanism of elimination of cells treated with cytotoxic agents initiated new studies deciphering the mechanism of apoptosis induced by emodin. At present, its role in combination chemotherapy with standard drugs to reduce toxicity and to enhance efficacy is pursued vigorously. Its additional inhibitory effects on angiogenic and metastasis regulatory processes make emodin a sensible candidate as a specific blocker of tumor-associated events. Additionally, because of its quinone structure, emodin may interfere with electron transport process and in altering cellular redox status, which may account for its cytotoxic properties in different systems. However, there is no documentation available which reviews the biological activities of emodin, in particular, its growth inhibitory effects. This review is an attempt to analyze the biological properties of emodin, a molecule offering a broad therapeutic window, which in future may become a member of anticancer armamentarium.

Sensitive and robust UPLC–MS/MS method to determine the gender-dependent pharmacokinetics in rats of emodin and its glucuronide

“…Therefore, in addition to the above mentioned effects, emodin’s health food and slimming product [9] intake has increased due to its weight loss property through its traditionally known stimulant laxative activity. As described previously, metabolism of emodin in vitro was gender different in rats and other four species animal [10] . However, again, no study has been done to show the gender differences in oral bioavailability of emodin in rodents as well as humans.…”

Antineoplastic activity of a methanolic extract from Kigelia pinnata DC stem bark

“…isopinnatal, kigelinole and isokigelinol, and kigelinone [22,23,27,43], the latter being characterized as cytotoxic agent and identified in other plants used as traditional antineoplastic remedies [16,44]. Moreover, quinone structural fragment is found in some important anticancer drugs, or investigational cytotoxic agents including the anthracycline antibiotics, mitoxanthrone, aloeemodin, lapachol (an identified constituent of K. africana) [21,35,[45][46][47][48] etc.…”

Química e farmacologia de quimioterápicos antineoplásicos derivados de plantas

“…Emodina é uma antraquinona com reconhecida ação vasorrelaxante, hepatoprotetora, imunossupressora e principalmente laxante, 88 porém tal composto tem mostrado bons resultados em testes iniciais para terapias anti-carcinogênicas, inibindo a proliferação celular, induzindo a apoptose e prevenindo metástases. 89 …”