Effects of oral interventions on carotid artery, serum C-reactive protein and interleukin 6 in chronic periodontitis rats with atherosclerosis

Abstract

Objective: To explore the effect of variousoral interventions on the development of atherosclerosis in SD rats with chronic periodontitis and atherosclerosis. Methods: Forty-four male SD rats were randomly divided into three groups, Group A(healthycontrol), Group B(atherosclerosis, As) and Group C(chronic periodontitis with atherosclerosis, CP+As). Rats in Group C were further divided randomly into Subgroup C1(natural process, n=7), Subgroup C2(mechanical therapy, n=7), Subgroup C3(systemic antibiotic treatment, n=7) and Subgroup C4(tooth extraction, n=7). Rats in each subgroup of Group C received one of the appropriate oral interventions. The pathological lesions of carotid artery plaque were stained with hematoxylin and eosin(HE) and observed under a light microscope. The serum levels of C-reactive protein(CRP) and interleukin-6(IL-6) were detected by enzyme-linked immunosorbent assay (ELISA) in five different time points. Results: Pathological results showed that increased foam cells and inflammatory cells were found in Group B. Irregular vessel wall, inflammatory cell, the foam cells, disordered elastic fibers were observed in Group C. While fewer in flammatory cells were found in Subgroup C2 than that in other subgroups. The changing trends of the serum levels of CRP and IL-6 were consistant with time went by. The levels of serum CRP, IL-6 in Groups B and C were significantly higher than that in Group A at all time points(P<0.01). The levels of serum CRP, IL-6 in Subgroup C1 became higher gradually(P<0.05) with time being. The serum levels after oral interventions changed significantly compared with the baseline levels(P<0.05). One week after the second round of intervention, the serum levels of CRP(C2: [9.43 ± 1.28] μg/L, C3: [12.38±0.81] μg/L, C4: [15.76±1.03] μg/L) and IL-6 (C2: [94.71±16.09] μg/L, C3: [112.89± 40.16] μg/L, C4: [175.11 ± 50.79] μg/L) in intervention subgroups reached the peaksand were significantly higher than that of Group B(CRP: [6.96±1.30] μg/L, IL-6: [43.36±7.46] μg/L) and Subgroup C1(CRP: [8.41± 0.46] μg/L, IL-6: [73.59±27.89] μg/L)(P<0.05). The changes of serum levels then declined with time beingin each group/subgroupand level in Subgroup C2 was the lowest(P<0.01). Conclusions: In chronic periodontitis of rats with atherosclerosis, permanent periodontitis mightsignificantly raise the risk of the development of atherosclerosis. Oral interventions increased the risk of atherosclerosis in a short period of time because of increased levels of serum inflammatory factors, but effective improvement could be observed on the As lesions after oral interventions in along term, especially after the periodontal mechanical therapy.