Evaluation of an Aqueous Extract from Horseradish Root (Armoracia rusticana Radix) against Lipopolysaccharide-Induced Cellular Inflammation Reaction

Figure 1

Efficacy of horseradish root on COX pathway activation in LPS stimulated human PBMC. (a) PBMC were stimulated with 1 μg/mL LPS for 36 h after treatment with the aqueous plant extract for 2 h. Cell viability was determined by the trypan blue exclusion test. Bars are mean (). (b, c) PBMC were analyzed with or without LPS stimulation for 3 h after pretreatment with the plant extracts for 3 h. Total cell lysate was analyzed using immunoblotting. The figure shows representative immunoblots of COX-1 or COX-2. Membranes were probed with antibodies against β-actin which acted as loading control. (d) PBMC were analyzed with or without LPS stimulation for 24 h after pretreatment with the plant extracts for 6 h. Supernatants were then used for photometric quantification of PGE₂ release using ELISA; bars are mean ± SEM (). (e) PBMC were pretreated with the complete aqueous extracts of horseradish or subfractions for 6 h followed by 18 h LPS stimulation (1 μg/mL). Supernatants were used for quantification of PGE₂ release. PGE₂ release was calculated relative to the LPS stimulated control; bars are mean ± SEM (). (f) COX-2 was incubated with either indomethacin, the aqueous extract, or the subfraction H4. COX-2 enzyme activity was analyzed by quantification of release using ELISA. release was calculated relative to the LPS stimulated control; bars are mean (). . BG: background, that is, inactivated COX-2 enzyme plus inhibitor.

(a)

(b)

(c)

(d)

(e)

(f)