Photobiomodulation therapy does not depend on the differentiation of dental pulp cells to enhance functional activity associated with angiogenesis and mineralization.

The purpose of this study is to analyze the influence of InGaAlP diode laser (660 nm) with or without an odontogenic medium (OM) in the functional activity of OD-21 cells. Undifferentiated OD-21 pulp cells were cultivated with or without OM and divided into four groups (n = 5): nonirradiated control (C -), nonirradiated + OM (C +), irradiated (L -), and irradiated + OM (L +). Laser application was performed in two sessions of a 24-h interval with an irradiance of 11.3 mW/cm2, energy density of 1 J/cm2, and total cumulative energy/well of 4.6 J. Cell proliferation, VEGF-164 expression, mineralization, and expression of Alp, Runx2, and Dmp1 genes, as well as immunolocalization of RUNX2 and MEPE proteins, were evaluated. Data were analyzed by statistical tests (α = 0.05). All studied groups showed a similar increase in cell proliferation with or without OM. After 7 and 10 days, a significatively higher concentration of VEGF-164 in L - group when compared to C - group was observed. A significant increase in mineralized nodules in the L + was noted when compared to C + in the same conditions. Photobiomodulation upregulated significantly Runx2 and Dmp1 expression after 10 days in L - and after 7 days in L + , with downregulation of Dmp1 after 10 days in L + group. Immunolocalization of RUNX2 and MEPE was expressive after 7 days of culture in the cytoplasm adjacent to the nucleus with a decrease after 10 days, regardless of the presence of OM. Photobiomodulation enhances metabolism associated with angiogenesis, gene expression, and mineralization regardless of the odontogenic medium in OD-21 cells.

Preadministration of yerba mate (Ilex paraguariensis) helps functional activity and morphology maintenance of MC3T3-E1 osteoblastic cells after in vitro exposition to hydrogen peroxide.

Natural substances with antioxidant effects may benefit prevention and treatment of people with or prone to bone diseases after menopause, such as osteoporosis. This study aimed to evaluate the in vitro effect of preadministration of yerba mate extract (YM) in the metabolism of MC3T3-E1 osteoblasts exposed to hydrogen peroxide (H2O2). The cells (MC3T3-E1) were cultured in 24-well plates with the concentration of 1 µg/mL yerba mate extract dissolved in culture medium throughout the culture period. Four hours before each experiment, 400 µmol/L H2O2 was added per well to simulate oxidative stress. There were evaluated cell adhesion and proliferation, in situ detection of alkaline phosphatase (ALP), mineralized nodules, and immunolocalization of osteocalcin (OCN), bone sialoprotein (BSP) and alkaline phosphatase (ALP) proteins. The results showed that YM preadministration to H2O2 exposition significatively increased cell adhesion after 3 days as well as proliferation and in situ ALP detection after 10 and 7 days respectively, when compared to H2O2 group. Besides, staining of OCN and BSP proteins was less intense and scattered in poor spread cells with cytoskeletal changes in H2O2 group when compared to control and YM H2O2 group. ALP staining was restrained to intracellular regions and similar in all experimental groups. Our results suggest that preadministration of yerba mate extract may prevent deleterious effects in the morphology and functional activity of osteoblasts exposed to H2O2, which could enable the maintenance of extracellular matrix in the presence of oxidative stress.