THE EFFECT OF KAEMPFEROL, ETHYL-p-METHOXYCINNAMATE, AND THE ETHANOL EXTRACT OF Kaempferia galanga RHIZOME ON THE PRODUCTION OF PROSTAGLANDIN BY In-vitro AND In-silico STUDY

Abstract

Cyclooxygenases (COX) catalyze the biosynthesis of prostaglandins from arachidonic acid, the substrate. COX has two isoforms which are targets of non-steroidal anti-inflammatory drugs (NSAIDs). NSAIDs exhibit their anti-inflammatory activity by blocking the conversion of arachidonic acid to prostaglandins. Overall, NSAIDs are well tolerated, especially when used short-term, nevertheless due to their global use, they are frequently involved in adverse drug reactions. Kaempferia galanga has been traditionally used to cure various inflammatory-related disorders by consuming the boiled rhizome tea or applying the rhizome powder paste topically on the inflamed site. This plant has been proven to contain flavonoids and polyphenolic compounds that are considered to have pharmacological activities. This work studied the effect of kaempferol (KAE), ethyl-p-methoxycinnamate (EPMC), and K. galanga rhizome ethanolic extract (EKG) on prostaglandin production and compared the results with that of celecoxib and triamcinolone acetonide by in vitro and in silico technique. Results revealed that both KAE and EPMC could occupy the catalytic site of COX-2 by building hydrogen bonds with important amino acid residues. Moreover, in vitro study confirmed that lower concentrations of EKG could reduce the production of prostaglandin PGG2, while higher concentration does not. It is proven that KAE inhibits the production of prostaglandin PGG2 in both concentration and time-dependent manners. Taken together, the EKG can be further developed as a COX-2 inhibitor drug.