RESUMEN
Fermented microalgae Pavlova lutheri (P. lutheri), the product of Hansenula polymorpha fermentation, exhibited an increase in alkaline phosphatase (ALP) activity in MG63 osteoblastic cells when compared to that of nonfermented P. lutheri. Fractionation of the fermented P. lutheri resulted in identification of the active peptide [peptide of P. lutheri fermentation (PPLF)] with the sequence of EPQWFL. PPLF significantly increased ALP release from MG63 cells and mineralization in a dosedependent manner. In addition, the intracellular levels of ALP and osteocalcin (OCN) proteins were augmented by PPLF treatment. To identify the molecular mechanism underlying the effect of PPLF on osteoblastic differentiation, the phosphorylation levels of the mitogenactivated protein kinases, p38, extracellular signalregulated kinases 1/2 and Jun, and nuclear factor (NF)κB were determined following PPLF treatment and the differences in expression were analyzed using p38 and NFκB selective inhibitors. These results concluded that PPLF from fermented P. lutheri induced osteoblastic differentiation by increasing ALP and OCN release in MG63 cells via the p38/p65 signaling pathway, indicating that PPLF supplement may be effective for therapeutic application in the field of bone health.