DPI (Diphenyleneiodonium chloride)

DPI inhibits the activity of NADPH oxidase, nitric oxide synthase, xanthine oxidase and NADPH cytochrome P450 oxidoreductase^[4].

Femtomolar concentrations of DPI exert potent anti-inflammatory and neuroprotective effects by inhibiting microglial activation through the inhibition of ERK-regulated PHOX activity^[1].

DPI has frequently been used to inhibit ROS production mediated by various flavoenzymes, including NAD(P)H oxidase, quinone oxidoreductase, cytochrome P450 reductase and nitric oxide synthase^[2].

NADPH, NADP+, and 2'5'-ADP blocks the inhibitory action of DPI^[3].

DPI treatment in ARPE-19 cells evoked a dose- and time-dependent growth inhibition, and also induced DNA fragmentation and protein content of the proapoptotic factor Bax. In addition, DPI significantly induced the expression and phosphorylation of p53, which induces proapoptotic genes in response to DNA damage or irreparable cell cycle arrest. ROS have been implicated as a key factor in the activation of p53 by many chemotherapeutic drugs^[4].

Diphenyleneiodonium (DPI), an NADPH oxidase inhibitor, inhibited the production of pro-inflammatory cytokines, (TNF-α and IL-6), reduced macrophage infiltration and classical polarization, and induced the ROS generation.

• Cell lines

  ARPE-19 cells

• Concentrations

  0.1, 1, and 10 μM

• Incubation Time

  6, 12, 24, and 48 h

• Method

  ARPE-19 cells are plated at 1×10⁶ cells per 60-mm dishes and incubated for 24 h. Cells are cultured in presence or absence of different concentrations of DPI in fresh DMEM/F12 medium supplemented with 10% FBS. After incubation, the cells are trypsinized, washed with phosphate-buffered saline (PBS) and the viable cells were scored by the trypan blue dye exclusion method using a hemocytometer.

• Animal Models

  Male C57BL/6 mice

• Dosages

  1 mg/kg

• Administration

  i.p.