Pharmacokinetics of 10-gingerol and 6-shogaol in the plasma of healthy subjects treated with red ginger ( var. Rubrum) suspension.

Red ginger ( var. Rubrum) is among the most widely consumed medicinal herbs in Indonesia. Ginger rhizome contains phenol compounds including gingerol and shogaol. 10-gingerol has been reported to exhibit the greatest anti-inflammatory and anti-oxidant activities compared with those of other gingerols. Pharmacokinetic studies on ginger have been reported, but there is a lack of such study on red ginger. The present work studied the pharmacokinetics of 10-gingerol and 6-shogaol in the plasma of healthy subjects treated with a single dose of red ginger suspension. Healthy subjects (n=19) were given a single dose of red ginger suspension (2 g/15 ml), and blood samples were taken at baseline (0 min), 30, 60, 90, 120, and 180 min. Analysis of 10-gingerol and 6-shogaol was performed by dissolving 200 µl of the subjects' plasma in 800 µl acetonitrile. The mixture was vortexed and centrifuged at 20,440 × g for 15 min at room temperature. The supernatant was filtered using Millipore membrane (pore size 0.2 µm) and injected into an RP-C18 column for liquid chromatography-mass spectrometry. A mixture of 0.1% (v/v) formic acid in water and acetonitrile (38:62) was used as the mobile phase. The maximum plasma concentration (Cmax) and time to reach Cmax of 10-gingerol and 6-shogaol were 160.49 ng/ml (38 min) and 453.40 ng/ml (30 min), respectively. The elimination half-lives were 336 and 149 min for 10-gingerol and 6-shogaol, respectively. Thus, 10-gingerol and 6-shogaol were absorbed after per oral single dose of red ginger suspension and could be quantified in the plasma of the healthy subjects. Additionally, the red ginger analytes exhibited relatively slow elimination half-lives.