Melatonin attenuates inflammation of acute pulpitis subjected to dental pulp injury.

Acute pulpitis (AP), one of the most common diseases in the endodontics, usually causes severe pain to the patients, which makes the search for therapeutic target of AP essential in clinic. Toll-like receptor 4 (TLR4) signaling is widely involved in the mechanism of pulp inflammation, while melatonin has been reported to have an inhibition for a various kinds of inflammation. We hereby studied whether melatonin can regulate the expression of TLR4/NF-ĸB signaling in the pulp tissue of AP and in human dental pulp cells (HDPCs). Two left dental pulps of the adult rat were drilled open to establish the AP model, and the serum levels of melatonin and pro-inflammatory cytokines, including interleukin 1ß (IL-1ß), interleukin 18 (IL-18) and tumor necrosis factor α (TNF-α), were assessed at 1, 3 and 5 d post injury. At the same time points, the expression of TLR4 signaling in the pulp was explored by quantitative real-time PCR and immunohistochemistry. The AP rats were administered an abdominal injection of melatonin to assess whether melatonin rescued AP and TLR4/NF-ĸB signaling. Dental pulp injury led to an approximately five-day period acute pulp inflammation and necrosis in the pulp and a significant up-regulation of IL-1ß, IL-18 and TNF-α in the serum. ELISA results showed that the level of melatonin in the serum decreased due to AP, while an abdominal injection of melatonin suppressed the increase in serum cytokines and the percentage of necrosis at the 5 d of the injured pulp. Consistent with the inflammation in AP rats, TLR4, NF-ĸB, TNF-α and IL-1ß in the pulp were increased post AP compared with the baseline expression. And melatonin showed an inhibition on TLR4/NF-ĸB signaling as well as IL-1ß and TNF-α production in the pulp of AP rats. Furthermore, melatonin could also regulate the expression of TLR4/NF-ĸB signaling in LPS-stimulated HDPCs. These data suggested that dental pulp injury induced AP and reduced the serum level of melatonin and that supplementation with melatonin may have a protective effect on AP by modulating TLR4/NF-ĸB signaling in the pulp and in pulp cells.

Intralesional injection of Pingyangmycin plus corticosteroids may be an effective treatment for cheilitis granulomatosa.

Cheilitis granulomatosa is a rare disease characterised by the recurrent labial swelling of one or both lips with the possibility of the condition to remain on a permanent basis. This kind of granulomatous, inflammatory disease may appear independently or be linked to a paralysis such as the facial and lingua plicata which then characteristic of the Melkersson-Rosenthal syndrome. Classically, a non-necrotizing granulomatous inflammation is seen at histologic examination. Many treatments have been tried. But as its high recurrence rate, the results were often disappointing. The major active component of Pingyangmycin is bleomycin A5. Currently, bleomycin has been proved to be a widely accepted treatment protocol for hemangiomas and lymphangioma. It has been proved that bleomycin could infiltrate prominently into lymphocytes and other inflammatory cells. Stromal connective tissue would proliferate markedly as the result of sclerotherapy. Oedema, lymphangiectasia and perivascular lymphocytic infiltration are always seen in cheilitis granulomatosa histologically. Therefore, we hypothesize that intralesional injection of Pingyangmycin plus corticosteroids may be a safe and effective treatment for cheilitis granulomatosa. The efficacy of this treatment modality is worthy of further investigation.