Melatonin has a stimulatory effect on osteoblasts by upregulating COL-I and OPN expression/secretion.

Abstract

Melatonin (MLT) is a potential signaling molecule in the homeostasis of bone metabolism and may be an important mediator of bone formation and stimulation. The aim of this in vitro study was to evaluate the effect of MLT on the viability, mRNA/protein expression and mineralization of pre-osteoblastic cells. The concentrations 5, 2.5, 1, 0.1 and 0.01 mM MLT were tested on pre-osteoblastic cells (MC3T3) compared to control (no MLT), evaluating proliferation and cell viability (C50), gene expression (RT-PCR) and secretion (ELISA) of COL-I and OPN at 24h, 48h and 72h, and the formation of mineral nodules (alizarin red and fast red) after 10 days of treatment. MLT at 5 and 2.5 mM proved to be cytotoxic (C50), so only 0.01, 0.1 and 1 mM were used for the subsequent analyses. OPN mRNA expression increased with MLT at 0.1 mM - 1 mM, which was followed by increased secretion of OPN both at 24h and 72h compared to the remaining groups (p <0.05). COL-I mRNA and COL-1 secretion followed the same pattern as OPN at 0.1 mM MLT at 72h of treatment (p <0.05). Regarding mineralization, all MLT doses (except 1mM) caused an increase (p <0.05) in the formation of mineral nodules compared to the control. Melatonin at 0.01mM - 1mM had a stimulatory effect on osteoblasts by upregulating COL-I and OPN expression/ secretion and mineralization, thereby fostering osteogenesis.

Influence of melatonin associated with the Bio-Gide® membrane on osteoblast activity: an in vitro study

“…Bone metabolism is more intense between days 7 and 21, while the highest remodeling rate is seen after 7 days 23 . Higher cell proliferation is seen after 72 hours, and mineral nodule formation, after 10 days 21 . Thus, as the purpose of this study is to assess the effect of MLT on the initial events of new bone formation, we consider that the period chosen for the analyses of this study was adequate.…”

“…In the recent years, research studies have been performed of the possible effects of melatonin on bone formation. Besides, melatonin has been used locally in bone regeneration procedures 18,21,22 .…”

“…ELISA test results for BMP2 did not show presence of immunomarkers in the secretion of such protein in the presence of MLT. Dalla-Costa et al 21 showed positive results with the secretion of Type I collagen and Osteoponin -key proteins in bone physiology-in the presence of MLT with a 1mM concentration. Another research study, by Tianyuan et al 22 , showed that, among the different BMPs, BMP-9 is one of the most effective factor for inducing osteogenesis in mesenchymal stem cells.…”

“…In the recent years, research studies have been performed of the possible effects of melatonin on bone formation. Besides, melatonin has been used locally in bone regeneration procedures 18 , 21 , 22 . Bearing in mind the importance of membranes in bone regeneration and of MLT in the initial proeesses of new bone formation, this research study performed, in an innovative manner, an in vitro assessment of the effeet on osteoblast eells derived from adding MLT to a resorbable membrane (Bio-Gide®).…”

“…In MLT, one of the mechanisms underlying its ability for regulating bone development is its stimulatory effect on osteoblasts. In in vitro human osteoblastic cells, melatonin has the ability of stimulating, in micromolar concentrations (nM), the proliferation and synthesis of Type I collagen, as well as of other proteins of the bone matrix and bone markers (alkalin phosphatase, osteopontin and osteocalcin) 18 , 20 , 21 . Yet, the action mechanism of MLT on these markers has not yet been entirely elucidated.…”