Propolis Inhibits UVA-Induced Apoptosis of Human Keratinocyte HaCaT Cells by Scavenging ROS

Abstract

Propolis is a resinous material collected by honeybees from several plant sources. This research aimed at showing its protective effect against UVA-induced apoptosis of human keratinocyte HaCaT cells. Using Hoechst staining, it was demonstrated that propolis (5 and 10 μg/mL) significantly inhibited the apoptosis of HaCaT cells induced by UVA-irradiation. Propolis also showed the protective effect against loss of mitochondrial membrane potential induced by UVA-irradiaiton in HaCaT cells. Propolis also inhibited the expression of activated caspase-3 induced by UVA-irradiation. To investigate the role of ROS in UVA-induced apoptosis and protection by propolis, the generation of ROS was determined in cells. The results showed that the generation of ROS was markedly reduced in cells pretreated with propolis. Consequently, propolis protected human keratinocyte HaCaT cells against UVA-induced apoptosis, which might be related to the reduction of ROS generation by UVA-irradiation.

3-Bromo-4,5-dihydroxybenzaldehyde Enhances the Level of Reduced Glutathione via the Nrf2-Mediated Pathway in Human Keratinocytes

“…Oxidative stress is known to change the composition and structure of cellular compounds such as DNA, lipids, and proteins by generating ROS [ 17 , 18 ], causing mutations, interruption of enzymatic activities, and degradation of cellular structures, ultimately leading to apoptosis [ 19 ]. Fortunately, cells have evolved antioxidant defense systems to maintain ROS concentrations at desirable levels [ 13 ].…”

Reactive oxygen species-dependent apoptosis induction by water extract of Citrus unshiu peel in MDA-MB-231 human breast carcinoma cells

“…In order to detect the production of intracellular ROS, 2′,7′-dichlorofluorescin diacetate (DCF-DA, Molecular Probes, Leiden, Netherlands) was used as described elsewhere [ 19 ]. Cells were treated with WECU for a certain period of time and then the cells were harvested, washed and re-suspended in 10 µM DCF-DA solution.…”

Induction of apoptosis by ethanol extract of <i>Citrus unshiu</i> Markovich peel in human bladder cancer T24 cells through ROS-mediated inactivation of the PI3K/Akt pathway

“…For the detection of intracellular ROS production, 2′,7′-dichlorofluorescin diacetate (DCF-DA, Molecular Probes, Leiden, Netherlands) dye was used according to the manufacturer's instructions (36). Briefly, after collecting the cells treated with EECU for a certain period of time, the cells were rinsed with PBS and then loaded with 10 μM DCF-DA for 20 min at 37°C in a dark room.…”