Effect Of Chronic Apical Periodontitis On Oxidative Stress Level In Hyperlipidemia Rats

Aim: The purpose of this study was to investigate the effect of chronic apical periodontitis(CAP)on oxidative stress(OS)level in hyperlipidemia rats.Methodology: 32 Sprague-Dawley(SD)rats were randomly divived into normal diet group(N group)and high-fat diet group(H group)according to their diet.Then hyperlipidemia model and CAP model(marked as 0 or 6 according to the number of CAP)were respectively built.At 14 th week(opening pulp 5 weeks),digital radiographs of right maxillas and mandible were used to make sure CAP model were successfully built.Then through immunohistochemical staining of 8-hydroxy-2-deoxyguanosine(8-OHd G)to measure oxidative DNA damage in periapical tissue;And the level of total antioxidant capacity(TAOC)and total oxidant status(TOS)were measured by enzyme-linked immunosorbent assays in periapical tissue,then calculated oxidative stress index(OSI)to analyze the effect of CAP on periapical tissue OS level in hyperlipidemia rats;Finally,the level of TAOC,TOS,malondialdehyde(MDA)in plasma and liver were detected,and calculated OSI to analyze the effect of CAP on plasma and liver OS level in hyperlipidemia rats.Results:(1)When compared to N0 group,the immunohistochemical staining of 8-OHd G of periapical tissue,MDA of plasma and liver were all significant increased in N6 group(P<0.05);However,no significant differences of 8-OHd G and MDA in periapical tissue,plasma and liver between N0 and H0 groups were found(P>0.05).(2)When compared to N0 group,although no significant differences of TAOC,TOS and OSI in periapical tissue and TOS of plasma and liver in N6 group were detected(P>0.05),TAOC of plasma and liver were significantly decreased,OSI were significantly elevated in N6 group(P<0.05).(3)In periapical tissue,plasma and liver,no significant differences of TAOC,TOS and OSI in H0 group were discovered,compared to N0 group(P>0.05).(4)When compared to N0 group,the immunohistochemical staining of 8-OHd G of periapical tissue,MDA of plasma and liver were all significant increased in H6 group(P<0.05).(5)Similar to the changes of N6 group,no significant differences of TAOC,TOS and OSI in periapical tissue and TOS of plasma and liver(P>0.05),TAOC of plasma and liver were lower,OSI were higher in H6 group than that in N0 group.These differences,however,only differences of plasma were statistically significant(P>0.05).Conclusions:(1)CAP combined hyperlipidemia,CAP could markedly increase oxidative DNA damage level of periapical tissue and lipid peroxidation level of plasma and liver of rats,yet hyperlipidemia did not cause any obviously changes.(2)CAP combined hyperlipidemia,CAP could reduce total antioxidant level and elevate OS level of plasma and liver of rats.However,only differences of plasma in two groups and differences of liver in CAP group were statistically significant;And CAP combined hyperlipidemia,CAP could not cause obviously changes in terms of total antioxidant,total oxidant and OS of periapical tissue,total oxidant level of plasma and liver;And hyperlipidemia could not induce obviously changes of total antioxidant,total oxidant and OS levels of periapical tissue,plasma and liver.(3)Under the condition of this research,hyperlipidemia could not significantly impact local and systemic OS level of rats,yet CAP could impact OS level of hyperlipidemia rats.