Ginkgolic Acids Confer Potential Anticancer Effects by Targeting Pro- Inflammatory and Oncogenic Signaling Molecules

Background: Medicinal plants and herbal preparations in the form of traditional medicines have been used in healthcare worldwide. The extracts of Ginkgo biloba L. seeds and leaves contain a complex mixture of numerous components, such as flavonol glycosides, terpene lactones, and a group of alkylphenols (anacardic or ginkgolic acids, cardanols and cardols) that have been a part of traditional Chinese medicine. These extracts are also sold as dietary supplements worldwide. G. biloba extract (EGb 761 and LI 1370) represent the standard form of G. biloba extract. Six different 6-alkylsalicylic acids (syn. ginkgolic acids) with alkyl substituents (C13:0, C15:0, C15:1, C17:0, C17:1, and C17:2) have been identified. Objective: The aim of this review is to unravel scientific evidence on anti-inflammatory and anticancer activities of ginkgolic acids to understand its therapeutic potential against inflammatory and oncologic diseases. Methods: A structured literature search was independently performed by the authors on PubMed, ScienceDirect, Scopus, and Web of Science. Accordingly, this review article critically analyses available scientific evidence on anti-inflammatory and anticancer activities of ginkgolic acids. Moreover, the review only included articles written in the English language. Results: Several forms of ginkgolic acids, especially C13:0, C15:0 and C17:1, isolated from the leaves of G. biloba exhibited cytotoxic activity against a variety of human cancers by suppressing various pro-inflammatory signaling cascades and oncogenic transcription factors through multiple modes of action in various in vitro and in vivo preclinical models. Ginkgolic acids have also been reported to be potent post-translational small ubiquitin-related modifiers (SUMO)ylation inhibitors. Conclusion: In this review, we present updated information on the anti-inflammatory and anticancer properties of ginkgolic acids both in vitro and in vivo. Although ginkgolic acids show significant therapeutic potential in inflammatory and oncologic diseases, more investigations regarding the safety and efficacy of these natural agents are warranted before the clinical transition.