Resveratrol strongly enhances the retinoic acid-induced superoxide generating activity via up-regulation of gp91-phox gene expression in U937 cells

Chalcone skeleton promotes transcription of gp91‐phox gene but inhibits expression of gp91‐phox protein, and hydroxyl groups in hydroxychalcones participate in the stable expression of gp91‐phox protein

“…(b) After culture of the cells with RA for 48 hr in the absence or presence of chalcone derivatives (2.5 μM [open bars] or 5 μM [closed bars]), cells (1 × 10 6 cells/mL) were stimulated with 200 ng/mL PMA at 37°C. PMA‐induced chemiluminescence was measured at 10 min after stimulation using a Lumat 3 LB9508 luminometer (Berthold Technologies, Bad Wildbad, Germany) as described previously . Quantitative data of O 2 ‐ generation are indicated as percentages of the control value obtained from RA‐treated U937 cells.…”

“…Second, the study examined the effects of chalcone derivatives on the regulation of the RA‐induced O 2 ‐ ‐generating ability. To determine the impact of chalcone and butein on the transcription of p22‐phox, gp91‐phox, p40‐phox, p47‐phox, and p67‐phox, semiquantitative reverse transcription polymerase chain reaction (RT‐PCR) analysis was performed as described previously . As shown in Figure a, transcription of gp91‐phox was prominently increased (to ~260%) by the addition of butein.…”

“…Therefore, a search was made for phytochemicals that could serve as effective drugs to treat leukemia by enhancing the effect of RA. Recently, using a RA‐induced differentiation system of U937 cells, we revealed that curcumin remarkably strengthens the RA‐induced O 2 ‐ ‐generating activity through enhancement of the expressions of p47‐phox and p67‐phox proteins, and that resveratrol markedly brings about up‐regulation of the RA‐induced O 2 ‐ ‐generating activity by enhancing the transcription of gp91‐phox gene . This study examined the effects of chalcone (1,3‐diphenyl‐2‐propen‐1‐one;Figure a) and its derivatives, especially 3,4,2′,4′‐tetrahydroxychalcone (butein), on the induction of O 2 ‐ ‐generating system in U937 cells.…”

“…(a) Effects of chalcone or butein on transcription of the five O 2 ‐ ‐generating system‐related factors. The mRNA levels of p22‐phox, gp91‐phox, p40‐phox, p47‐phox, and p67‐phox were determined by semiquantitative RT‐PCR using total RNAs extracted from RA‐treated and RA plus 2.5 μM chalcone or butein‐treated U937 cells as described previously …”

“…(b) Effects of chalcone derivatives on transcription of gp91‐phox. Total RNAs extracted from RA‐treated and RA plus 2.5 μM various chalcone derivatives‐treated U937 cells as described previously . Semiquantitative RT‐PCR was carried out as described in (a).…”