FIGURE 3.

Propolis increased the cytotoxic effect of PDT through three possible mechanistic actions: 1) increased the intracellular uptake and accumulation of PDT; 2) enhanced the apoptotic signaling by regulating the pro-apoptotic and apoptotic proteins; 3) Inhibited pIKK-NFκB signaling, leading to reduced cell survival. In addition, propolis may reduce the local and systemic inflammation through the inhibition of the NF-κB pathway. Red arrows represent the action of propolis in the combination, whereas black arrows represent the action of PDT.