Demethylzeylasteral from Costus dubius (Afzel.)  K. Schum Leaves Inhibits Cyclooxygenase (COX-2) In vitro

One of the widely studied plant families is the costaceae family also called “Spiral Ginger Family”, known to contain bioactive compounds. However, Costus dubius (Afzel.) K. Schum., a member of this family, has not yet been explored for its potential bioactivity. Through a series of chromatographic separations and purification, demethylzeylasteral, a potential analgelsic compound, ​was​ isolated from the sub-fractions of the hexane extract of C. dubius leaves. It inhibited both COX-2 with an IC50 of 77.97 ± 14.05 μM and COX-1 with an IC50 of 158.90 ± 16.00 μM in a concentration-dependent manner. These results demonstrate that demethylzeylasteral is more selective against COX-2 than COX-1, which is desirable because COX-2 is the enzyme targeted for pain and inflammation while inhibition of COX-1 is associated with maintaining gastrointestinal integrity. This is the first report on the COX-1 and COX-2 inhibitory activity of demethylzeylasteral.