Green tea polyphenol (–)-epigallocatechin-3-gallate prevents ultraviolet-induced apoptosis in PC12 cells
	    		
		   		
		   			
		   		
	    	
    	 
    	10.11620/IJOB.2020.45.4.179
   		
        
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Su-Mi WOO
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Yoon-Jung KIM
			        		
			        		;
		        		
		        		
		        		
			        		Bangrong CAI
			        		
			        		;
		        		
		        		
		        		
			        		Sam-Young PARK
			        		
			        		;
		        		
		        		
		        		
			        		Young KIM
			        		
			        		;
		        		
		        		
		        		
			        		Ok Joon KIM
			        		
			        		;
		        		
		        		
		        		
			        		In-Chol KANG
			        		
			        		;
		        		
		        		
		        		
			        		Won-Jae KIM
			        		
			        		;
		        		
		        		
		        		
			        		Ji-Yeon JUNG
			        		
			        		
		        		
		        		
		        		
		        		
		        			
			        		
			        		Author Information
			        		
		        		
		        		
			        		
			        		
			        			1. Department of Oral Physiology, Dental Science Research Institute, School of Dentistry, Chonnam National University, Gwangju 61186, Republic of Korea
			        		
		        		
	        		
        		 
        	
        	
        	
        		- Publication Type:Original Article
 
        	
        	
            
            
            	- From:International Journal of Oral Biology
	            		
	            		 2020;45(4):179-189
	            	
            	
 
            
            
            	- CountryRepublic of Korea
 
            
            
            	- Language:English
 
            
            
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		        	Abstract:
			       	
			       		
				        
				        	 Green tea polyphenol (–)-epigallocatechin-3-gallate (EGCG) is a potent antioxidant with protective effects against neurotoxicity. However, it is currently unclear whether EGCG protects neuronal cells against radiation-induced damage. Therefore, the objective of this study was to investigate the effects of EGCG on ultraviolet (UV)-induced oxidative stress and apoptosis in PC12 cells. The effects of UV irradiation included apoptotic cell death, which was associated with DNA fragmentation, reactive oxygen species (ROS) production, enhanced caspase-3 and caspase-9 activity, and poly (ADP-ribose) polymerase cleavage. UV irradiation also increased the Bax/Bcl-2 ratio and mitochondrial pathway-associated cytochrome c expression. However, pretreatment with EGCG before UV exposure markedly decreased UV-induced DNA fragmentation and ROS production. Furthermore, the UV irradiationinduced increase in Bax/Bcl-2 ratio, cytochrome c upregulation, and caspase-3 and caspase-9 activation were each ameliorated by EGCG pretreatment. Additionally, EGCG suppressed UV-induced phosphorylation of p38 and rescued UV-downregulated phosphorylation of ERK. Taken together, these results suggest that EGCG prevents UV irradiationinduced apoptosis in PC12 cells by scavenging ROS and inhibiting the mitochondrial pathways known to play a crucial role in apoptosis. In addition, EGCG inhibits UV-induced apoptosis via JNK inactivation and ERK activation in PC12 cells. Thus, EGCG represents a potential neuroprotective agent that could be applied to prevent neuronal cell death induced by UV irradiation.