Figure 3. GPE inhibits NOX activity in human PCa cells.

(A–C) Human PCa 22Rv1, LNCaP and PC3 cells were seeded at the density of 4 × 10⁵ cells/60 mm culture dishes. After 24 h of seeding, cells were treated with 1, 2.5 and 5 μg/ml concentrations of GPE under hypoxic condition (1% O₂) for 24 h. In each case, cells cultured under normoxic condition (21% O₂) served as relevant control. At the end of 24 h, cells were harvested and NOX activity was measured as mentioned in ‘Materials and Methods’ and represented as rlu/mg protein. (D) Direct inhibition of NOX activity by GPE was assessed by pre-incubating GPE (1.0–5.0 μg/ml) with cellular homogenates and NOX activity was measured as mentioned in ‘Materials and Methods’ and represented as rlu/mg protein. Each value represents mean ± SEM of three samples for each treatment. ^$p ≤ 0.05; ^#p ≤ 0.01; *p ≤ 0.001.