Potential of Alpinia galanga Rhizome and Pseudostem Extracts on Anti-free Radical and Anti-cholinesterase Activities

Abstract

The objective of this research is to improve the potential of Alpinia galanga (L.) Willd. For prevention and rehabilitation of Alzheimer’s disease. Ethanolic, ethyl acetate, dichloromethane, and hexane extracts of galangal pseudostem and rhizome were subjected to screen for phytochemicals, including carbohydrates, proteins, alkaloids, polyphenols, flavonoids, anthocyanins, and tannins. Furthermore, these extracts were assessed for their radical scavenging, anti-acetylcholinesterase, and anti-butyrylcholinesterase activities. The result of phytochemical screening indicated that polyphenols were observed in the ethanolic, ethyl acetate, and dichloromethane extracts of galangal pseudostem. For biological activity evaluations, the dichloromethane pseudostem extract at 0.1 mg/mL. concentration exhibited the highest inhibitory activity against free radical (95.48%). Moreover, this extract at 0.2 mg/mL. concentration also possessed the highest acetylcholinesterase (88.57%). The concentration providing 50% acetylcholinesterase inhibition (IC 50) of the extract was 0.158 mg/mL. The hexane rhizome extract at 0.2 mg/mL concentration presented the greatest butyrylcholinesterase inhibitory activity (57.84%), followed by the dichloromethane pseudostem extract at 0.2 mg/mL concentration (39.09%). These findings suggested the potential of using dichloromethane extract of galangal pseudostem for prevention and treatment of Alzheimer’s disease. Consequently, further research focusing on extraction development and bioactive compounds identification from this extract should be carried out.