Carvedilol decrease IL-1β and TNF-α, inhibits MMP-2, MMP-9, COX-2, and RANKL expression, and up-regulates OPG in a rat model of periodontitis

Abstract

Periodontal diseases are initiated primarily by Gram-negative, tooth-associated microbial biofilms that elicit a host response that causes osseous and soft tissue destruction. Carvedilol is a β-blocker used as a multifunctional neurohormonal antagonist that has been shown to act not only as an anti-oxidant but also as an anti-inflammatory drug. This study evaluated whether Carvedilol exerted a protective role against ligature-induced periodontitis in a rat model and defined how Carvedilol affected metalloproteinases and RANKL/RANK/OPG expression in the context of bone remodeling. Rats were randomly divided into 5 groups (n = 10/group): (1) non-ligated (NL), (2) ligature-only (LO), and (3) ligature plus Carvedilol (1, 5 or 10 mg/kg daily for 10 days). Periodontal tissue was analyzed for histopathlogy and using immunohistochemical analysis characterized the expression profiles of MMP-2, MMP-9, COX-2, and RANKL/RANK/OPG and determined the presence of IL-1β, IL-10 and TNF-α, myeloperoxidase (MPO), malonaldehyde (MDA) and, glutathione (GSH). MPO activity in the group with periodontal disease was significantly increased compared to the control group (p<0.05). Rats treated with 10 mg/kg Carvedilol presented with significantly reduced MPO and MDA concentrations (p<0.05) in addition to presenting with reduced levels of the pro-inflammatory cytokines IL-1 β and TNF-α (p<0.05). IL-10 levels in Carvedilol-treated rats remained unaltered. Immunohistochemical analysis demonstrated reduced expression of MMP-2, MMP-9, RANK, RANKL, COX-2, and OPG in rats treated with 10 mg/kg Carvedilol. This study demonstrated that Carvedilol affected bone formation/destruction and anti-inflammatory activity in a rat model of periodontitis.

Figure 1. Microscopic analysis.

(A) Normal periodontium and (B) periodontium from a rat presenting with periodontitis (treated with saline) showing alveolar bone and cementum resorption and inflammatory cell infiltration. (C) Reduced inflammation and alveolar bone loss in the periodontium of rats treated with Carvedilol (10 mg/kg) for 10 days. Sections were stained with H&E. Microscopic original magnification at 40X. Scale bars = 100 µm. G = gingiva; PL = Periodontal ligament; D = dentin; AB = alveolar bone; C = Cementum; a = bone loss; b = resorption of cementum; c = inflammatory process; e, f = decreased inflammation process and bone loss.

Figure 2. Immunoreactivity to MMP-2, MMP-9, COX-2, RANK, RANK-L, and OPG. Photomicrographs of periodontal tissues from rats presenting with EPD and treated with Carvedilol (10 mg/kg) (A, D, G, J, M, P).

Rats treated with saline only (B, E, H, K, N, Q) and untreated rats presenting with EPD (C, F, I, L, O, R). Magnification 40X, bar scale = 100 µm. Pulp tissue (P), gingiva (G), periodontal ligament (PL), and dentina (D).

Figure 3. MPO, MDA, and GSH levels were measured in the NL, L and CARVE 1, 5, and 10 mg/kg groups.

#,*p<0.05.

Figure 4. IL-1β, IL-10, and TNF-α levels were measured in the NL, L and CARVE 1, 5, and 10 mg/kg groups.

^#,*p<0.05;