Extract, fractions, and ethyl- p-methoxycinnamate isolate from Kaempferia galanga Elicit anti-inflammatory activity by limiting leukotriene B4 (LTB4) production

J Tradit Complement Med. 2021 Jun 22;11(6):563-569. doi: 10.1016/j.jtcme.2021.06.004. eCollection 2021 Nov.

Abstract

Background and aim: Kaempferia galanga, also known as aromatic Ginger (kencur) in Indonesia, has been widely explored and shows potential as an anti-inflammatory agent. However, there has been limited research to show a possible mechanism by which aromatic ginger inhibits lipoxygenase (LOX). Therefore, this study aims to determine the anti-inflammatory activity of aromatic ginger by comparing extract, fractions, and ethyl-p-methoxycinnamate (EPMC) isolate, as well as possible LOX inhibition activity, by reducing the production of leukotriene B4 (LTB4).

Experimental procedure: Two animal models were used, namely, the carrageenan-induced granuloma air pouch model and the pleurisy model. The test substance was administered 1 h before carrageenan induction, which was performed orally for each animal model. The number of leukocytes and the malondialdehyde (MDA) levels, leukotriene B4 (LTB4) levels, and histology were observed. GC-MS and LC-MS were used for analysis of the chemical compounds in the test samples.

Results and conclusion: The results of GC-MS analysis showed that aromatic ginger rhizome extract and fractions were dominated by ethyl-trans-p-methoxycinnamate, with the highest level found in the extract. K. galanga showed significant anti-inflammatory activity compared to the control (p < 0.01) in both the granuloma air pouch and pleurisy models. The results of examining the LTB4 concentration showed comparable activity between K. galanga extract, fractions and EMPC isolate, these results were not better than those of zileuton. Overall, this study shows that aromatic ginger extract, fractions and EPMC isolate have anti-inflammatory properties and have the potential to inhibit LOX, thereby reducing LTB4 levels.

Keywords: AA, arachidonic acid; ARDS, acute respiratory distress syndrome; Anti-inflammation; COPD, chronic obstructive pulmonary disease; COX, cyclooxygenase; E, ethanol extract; EAF, ethyl acetate fraction; EPMC, ethyl-p-methoxycinnamate; FLAP, 5-lipoxygenase-activating protein; Granuloma-air pouch; HF, n-hexane fraction; IBD, inflammatory bowel disease; IL, interleukin; LOX, lipoxygenase; LTA4H, LTA4 hydrolase; LTB4, leukotriene B4; Lipoxygenase; MDA, malondialdehyde; PG, prostaglandin; Pleurisy; TBA, thiobarbituric acid; TEP, tetraethoxypropane; TNF-α, tumor necrosis factor-α; WF, water fraction.