Anti-Inflammatory Effects of Melatonin and 5-Methoxytryptophol on Lipopolysaccharide-Induced Acute Pulpitis in Rats

Abstract

Aim. The aim of this study was to investigate the possible therapeutic impacts of two pineal hormones, melatonin and 5-methoxytryptophol (5-MTX), in a rat model of acute pulpitis by analyzing biochemical and histopathological parameters. Methods. This research was done using 32 male and female Wistar albino rats with weight between 200 and 250 g. The rats were randomly divided into four groups: a control group (rats without any treatment), acute pulpitis (AP) group, AP+melatonin group, and AP+5-MTX group. In the AP-induced groups, the crowns of the upper left incisors were removed horizontally. Lipopolysaccharide solution was applied to the exposed pulp tissue before the canal orifices were sealed with a temporary filling material. Melatonin (10 mg/kg) and 5-MTX (5 mg/kg) were administered intraperitoneally. The rats were sacrificed 24 hours after pulp injury, and trunk blood and pulp samples were collected. The concentrations of TNF-α, IL-1β, MMP-1, and MMP-2 in sera and pulp samples were determined using ELISA assay kits. Results. TNF-α, IL-1β, MMP-1, and MMP-2 levels in the serum and pulp tissues were considerably higher in the AP group than the control group ( p < 0.01 ‐ 0.001 ). In the AP+melatonin and AP+5-MTX groups, TNF-α, IL-1β, MMP-1, and MMP-2 levels in the serum and pulp tissues were significantly lower than in the AP group ( p < 0.05 ‐ 0.001 ). Conclusions. Both melatonin and 5-MTX provided protective effects on acute pulpitis, which indicates they may be promising as a therapeutic strategy for oral disease.

RETRACTED: Activation of the P2X7 receptor in the dental pulp tissue contributes to the pain in rats with acute pulpitis

“… 20 , 21 Studies have shown that the medullary cavity built-in LPS method is reliable in establishing a rat model to simulate the process of clinical acute pulpitis. 15 Therefore, the early stage of the acute pulpitis after 24 h of modeling was selected as the main observation time point in detecting the changes of pain-related behaviors, pulp histopathological changes, and the P2X7 receptor expression in pulp tissue with all the experimental rats in each group.…”

“…The experiment of AP in the rat model was established because from the report of Kermeoglu . 15 After administering anesthesia with phenobarbital sodium (60 mg/kg, intraperitoneal injection), rats were placed in supine position in preparation for surgery. The rat’s mouth was kept open with a metal mouth gag, thus the operation area was sterilized with 75% ethanol.…”

Matrix Metalloproteinases in Dental and Periodontal Tissues and Their Current Inhibitors: Developmental, Degradational and Pathological Aspects

“…In an animal study, MMP-9 and MMP-2 have a strong correlation with progression of apical periodontitis [ 64 ]. Melatonin and 5-methoxytryptophol are effective in reducing MMP-1 and -2 levels in the serum and pulp tissue of acute pulpitis models in rats pointing to future potential therapeutic measures [ 65 ].…”

Evaluation of Pulp Repair after BiodentineTM Full Pulpotomy in a Rat Molar Model of Pulpitis

“…In addition, our study is original in that in most cases of experimental induced pulpitis in rats, the studies were realized on incisors. However, rodent incisors are continuously erupting teeth with high healing potential after pulp injury, thus removing them from human clinical reality [26,27].…”

“…In this study, we evaluated the ability of DP to heal after stimulation with LPS. LPS-induced dental pulp inflammation represents a stable experimental inflammation model for the dynamic observation of the progress of acute and chronic pulpitis [27]. We chose LPS from Escherichia coli for its ability to stimulate the TLR4 receptor, an ability similar to Gram-negative bacteria found in deep caries [3,26,31,32].…”