Perilla Seed Meal Extract Enriched with Rosmarinic Acid and Luteolin: Natural Active Pharmaceutical Ingredients (NAPIs) for Osteoprotective Effects

Perilla seed meal (PSM) is a waste biomass of perilla seed extraction that retains flavonoid and phenolic compounds. In this study, we aimed to investigate the potential of PSM extracts (PSMEs) from Perilla frutescens (L.) Britton as a sustainable source of natural active pharmaceutical ingredients (NAPIs) containing rosmarinic acid and luteolin for promoting bone health. PSMEs were obtained through shaking incubation and ultrasonic extraction, with 40% ethanol (PS-E40) and 80% ethanol (PS-E80) being found to be the most effective solvents. The effects of PSMEs on bone formation markers were evaluated in human fetal osteoblast cells (hFOB 1.19) using bone formation parameters. The results demonstrated that PS-E40 and PS-E80 extracts significantly increased alkaline phosphatase (ALP) activity, osteocalcin (OC) production, and osteoprotegerin (OPG) levels while concurrently reducing receptor activator of nuclear factor kappa-Β ligand (RANKL) and reactive oxygen species (ROS) production in a dose-dependent manner, particularly at 100 µg/mL on day 7 and 50 and 100 µg/mL on day 14 of the co-incubation period. Moreover, Alizarin Red S staining demonstrated that PS-E40 enhanced calcium deposition in both normal and osteogenic media, further supporting the effect of PSMEs on mineralization and osteoblast differentiation. Our findings suggest that PSMEs rich in rosmarinic acid and luteolin enhance bone health by promoting osteoblast activity and reducing osteoclastogenesis.