Anthocyanin-Rich Nerello Mascalese Pomace Extract: Effects on Osteoblast Differentiation and Bone Matrix Mineralization

Impaired bone formation and extracellular matrix mineralization contribute to the progressive loss of bone quality associated with aging and skeletal disorders. In this context, the growing interest in sustainable bioactive ingredients for health-related and nutraceutical applications has drawn attention to grape pomace, a phenol-rich byproduct of winemaking. This study investigated the chemical composition and osteogenic potential of Nerello Mascalese pomace extract (NMPE), evaluating its effects on key processes involved in human osteoblast differentiation, extracellular matrix maturation, and mineralized matrix formation. NMPE was chemically characterized by means of liquid chromatographic techniques, revealing a phenolic-rich profile dominated by anthocyanins. The osteogenic effects of NMPE were evaluated by analyzing extracellular matrix mineralization through Alizarin Red S staining, alkaline phosphatase (ALP) enzymatic activity, and the expression of genes involved in osteoblast differentiation and matrix mineralization by quantitative real-time PCR. NMPE promoted osteoblast differentiation and extracellular matrix mineralization, together with coordinated changes in the expression of osteogenesis- and matrix-associated genes. These findings identify Nerello Mascalese pomace as a promising source of bioactive compounds capable of supporting bone-forming processes and strengthen its potential for sustainable valorization in bone-health applications.