Pharmacology and toxicology of α- and ß-Asarone: A review of preclinical evidence.

ABSTRACT

BACKGROUND: Asarone is one of the most researched phytochemicals and is mainly present in the Acorus species and Guatteria gaumeri Greenman. In preclinical studies, both α- and ß-asarone have been reported to have numerous pharmacological activities and at the same time, many studies have also revealed the toxicity of α- and ß-asarone. PURPOSE: The purpose of this comprehensive review is to compile and analyze the information related to the pharmacokinetic, pharmacological, and toxicological studies reported on α- and ß-asarone using preclinical in vitro and in vivo models. Besides, the molecular targets and mechanism(s) involved in the biological activities of α- and ß-asarone were discussed. METHODS: Databases including PubMed, ScienceDirect and Google scholar were searched and the literature from the year 1960 to January 2017 was retrieved using keywords such as α-asarone, ß-asarone, pharmacokinetics, toxicology, pharmacological activities (e.g. depression, anxiety). RESULTS: Based on the data obtained from the literature search, the pharmacokinetic studies of α- and ß-asarone revealed that their oral bioavailability in rodents is poor with a short plasma half-life. Moreover, the metabolism of α- and ß-asarone occurs mainly through cytochrome-P450 pathways. Besides, both α- and/or ß-asarone possess a wide range of pharmacological activities such as antidepressant, antianxiety, anti-Alzheimer's, anti-Parkinson's, antiepileptic, anticancer, antihyperlipidemic, antithrombotic, anticholestatic and radioprotective activities through its interaction with multiple molecular targets. Importantly, the toxicological studies revealed that both α- and ß-asarone can cause hepatomas and might possess mutagenicity, genotoxicity, and teratogenicity. CONCLUSIONS: Taken together, further preclinical studies are required to confirm the pharmacological properties of α-asarone against depression, anxiety, Parkinson's disease, psychosis, drug dependence, pain, inflammation, cholestasis and thrombosis. Besides, the anticancer effect of ß-asarone should be further studied in different types of cancers using in vivo models. Moreover, further dose-dependent in vivo studies are required to confirm the toxicity of α- and ß-asarone. Overall, this extensive review provides a detailed information on the preclinical pharmacological and toxicological activities of α-and ß-asarone and this could be very useful for researchers who wish to conduct further preclinical studies using α- and ß-asarone.