Anti-inflammatory activity of Alpinia nantoensis extracts

Innate immune cells defense harmful stimuli such as bacteria endotoxin through inducing a complex inflammatory response; however, unrestrained inflammation leads to a range of inflammatory diseases, including asthma, atherosclerosis, rheumatoid arthritis, inflammatory bowel disease, and cancers. Controlling inflammatory processes is considered as one of approach to limit the progression of these diseases. In this study, we investigated the aerial and underground parts extract of Alpinia nantoensis F. Y. Lu & Y. W. Kuo (zigiberaceae) for anti-inflammatory activity in the lipopolysaccharide (LPS)-stimulated macrophage. Our results showed the aerial part of ethanolic extract and the underground part of hexanoic extract have more potent activity on inhibition of LPS-induced nitric oxide (NO) production, with a half-maximal inhibitory (IC₅₀) values of 1.83 ± 0.2 µg/ml and 9.6 ± 0.4 µg/ml, respectively. Compounds cardamonin and pinostrobin (PSB) from active fractions showed have potent activity on inhibition of NO formation than 3,5-dimethoxystilbene (35DS), with an IC₅₀ concentration of 3.28 ± 1.2µM, 83.40 ± 0.8µM, and > 100µM, respectively. The levels of NO formation by extracts or pure compounds treatment was paralleled with the levels of inducible nitric oxide synthase (iNOS) protein expression. Other pro-inflammatory factors, cyclooxygenase-2 (COX-2), IL-6, and TNF-alpha were also investigated. Compounds cardamonin, PSB, and 35DS displayed the different extent of inhibition on LPS-induced COX-2, IL-6, and TNF-alpha expression, as well as PGE2 formation. Our study suggests that the constituents of A. nantoensis have the potential to development anti-inflammatory drugs.

[1] Kuo YW, Lu FY, Duh MH, Deng SL. Taiwan J For Sci 2008; 23: 93 – 7, 2008