Caffeic acid treatment augments the cell proliferation, differentiation, and calcium mineralization in the human osteoblast-like MG-63 cells

Methanolic extract of O.umbellata L. exhibits anti-osteoporotic effect via promoting osteoblast proliferation in MG-63 cells and inhibiting osteoclastogenesis in RANKL-stimulated RAW 264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Oldenlandia umbellataL., belonging to the Rubiaceae family, is an annual plant possessing anti-inflammatory and antipyretic, anti-nociceptive, anti-bacterial, anti-helminthic, antioxidant and hepatoprotective activities and used in traditional medicine to treat inflammation and respiratory diseases.

AIM OF THE STUDY

The present study aims to evaluate the anti-osteoporotic effect of Methanolic extract of O.umbellata in MG-63 cells and RANKL-stimulated RAW 264.7 cells.

MATERIALS AND METHODS

The methanolic extract from the aerial parts of O.umbellata was subjected to metabolite profiling. The anti-osteoporotic effect of MOU was assessed in MG-63 cells and RANKL-stimulated RAW 264.7 cells. In MG-63 cells, the proliferative effect of MOU was evaluated using MTT assay, ALP assay, Alizarin red staining, ELISA and western blot. Similarly, the anti-osteoclastogenic effect of MOU was assessed in RANKL-stimulated RAW 264.7 cells via MTT, TRAP staining and western blot.

RESULTS

LC-MS metabolite profiling showed the presence of 59 phytoconstituents including scandoside, scandoside methyl ester, deacetylasperuloside, asperulosidic acid, and cedrelopsin in MOU. In MG-63 cells, MOU has increased the proliferation of osteoblast cells and ALP activity, thereby increasing bone mineralization. ELISA results showed increased levels of osteogenic markers such as osteocalcin and osteopontin in the culture media. Western blot analysis showed inhibition of GSK3β protein expression and increased the expression levels of β-catenin, Runx-2, col 1 and osterix, promoting osteoblast differentiation. In RANKL-stimulated RAW 264.7 cells, MOU did not elicit any significant cytotoxicity; instead, it suppressed the osteoclastogenesis reducing the osteoclast number. MOU has reduced TRAP activity in a dose-dependent manner. MOU inhibited the TRAF6, NFATc1, c-Jun, C-fos and cathepsin K expression, thereby inhibiting osteoclast formation.

CONCLUSION

In conclusion, MOU promoted osteoblast differentiation via inhibiting GSK3β and activating Wnt/β catenin signalling and its transcription factors, including β catenin, Runx2 and Osterix. Similarly, MOU inhibited osteoclast formation by inhibiting the expression of TRAF6, NFATc1, c-Jun, C-fos and cathepsin K in RANK-RANKL signalling. Finally, it can be emphasised that O.umbellata is a potential source of therapeutic leads for the treatment of osteoporosis.

Distinctions in bone matrix nanostructure, composition, and formation between osteoblast-like cells, MG-63, and human mesenchymal stem cells, UE7T-13

Osteoblast-like cells and human mesenchymal stem cells (hMSCs) are frequently employed as osteoprogenitor cell models for evaluating novel biomaterials in bone healing and tissue engineering. In this study, the characterization of UE7T-13 hMSCs and MG-63 human osteoblast-like cells was examined. Both cells can undergo osteogenesis and produce calcium extracellular matrix; however, calcium nodules produced by MG-63 lacked a central mass and appeared flatter than UE7T-13. The absence of growing calcium nodules in MG-63 was discovered by SEM-EDX to be associated with the formation of alternating layers of cells and calcium extracellular matrix. The nanostructure and composition analysis showed that UE7T-13 had a finer nanostructure of calcium nodules with a higher calcium/phosphate ratio than MG-63. Both cells expressed high intrinsic levels of collagen type I alpha 1 chain, while only UE7T-13 expressed high levels of alkaline phosphatase, biomineralization associated (ALPL). High ALP activity in UE7T-13 was not further enhanced by osteogenic induction, but in MG-63, low intrinsic ALP activity was greatly induced by osteogenic induction. These findings highlight the differences between the two immortal osteoprogenitor cell lines, along with some technical notes that should be considered while selecting and interpreting the pertinent in vitro model.