Apoptotic effects of artificial feed supplemented with <i>Thymus vulgaris</i> on <i>Oncorhynchus mykiss</i> against <i>Yersinia ruckeri</i>

Abstract

Chemical composition of the essential oil was analyzed by GC-MS, and found to contain the phenol (40.95 %) as major component. Results showed that <i>Y. ruckeri</i> (3 x 10⁷cfu fish^-1) infection caused the characteristic symptoms on rainbow trout (petechial hemorrhages on the surface of body and liver). <i>Y. ruckeri</i> inducedinhibitions of Cas-3, Cas-8, p53 and HSP-70. After the administration of thyme essential oil (10 mg kg^-1 diet) to infected fish tissues, Cas-3, Cas-8, p53 and HSP-70 mRNAs were up-regulated by 9.31, 9.18, 9.58, and 6,1 fold change, respectively. According to the results of the study, the inhibitions seen all analyzed genes were due to <i>Y. ruckeri</i> infection. However, they were entirely increased by thyme treatment. Thus, targeting pro-apoptotic proteases by agents such as <i>T. vulgaris</i> could improve therapeutic options for infectious disease in fish.