FIG. 2.

Capsaicin increases ROS generation in UB/OC-1 cells. UB/OC-1 cells exposed to capsaicin demonstrated increased ROS generation as measured by H₂DCFDA dye. (A) Cells were pretreated with different concentrations of capsaicin (0–2.5 μM) for 15 min, followed by incubation with H₂DCFDA dye. The fluorescence intensity increased with increasing capsaicin concentrations. (B) Capsaicin-mediated increase in ROS generation was abrogated after knockdown of TRPV1 channels using siRNA. UB/OC-1 cells were transfected with TRPV1-siRNA for 48 h, and ROS generation was assessed in these cells after 15 min capsaicin treatment. TRPV1-siRNA alone did not alter the level of ROS generation. Data presented in (A) and (B) were replicated at least three times with similar results. Scale bar (lower right panels) represent 10 μm. H₂DCFDA, 2′,7′-dichlorodihydrofluorescein diacetate; ROS, reactive oxygen species; siRNA, short interfering RNA; TRPV1, transient receptor potential 1. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article at www.liebertonline.com/ars).