7F2 Preosteoblast Cell Line Relative Viability Percentage after the Administration of 1% Roselle Flower Extract Nanoemulsion (Hibiscus sabdariffa Linn.)

The roselle flower (<i>Hibiscus sabdariffa</i>) has shown potential as an alternative therapy for bone regeneration. This flower extract can induce osteoblast maturation, which is crucial for forming new bone. The study aim was to evaluate the viability of the 7F2 preosteoblast cell line following the application of a roselle flower nanoemulsion extract (RNE).This study utilized the 7F2 preosteoblast cell line to assess cell viability (%). The RNE was oven-dried at 35 to 40°C for 6 hours, resulting in a solid extract. The extract was then diluted into different concentrations. The preparation of 1% RNE was stirred at 1,400 rpm at 50°C for 90 minutes. Primary cultures of preosteoblast cell lines (7F2 cells) were distributed across 10 wells. Well 1 served as the positive control, representing 100% cell viability. Well 2 acted as the media control, containing only culture media without cells, representing 0% cell viability. Wells 3 to 10 were exposed to 1% RNE at serial concentrations of 100, 50, 25, 12.5, 6.25, 3.125, 1.56, and 0.78%. The viability of the 7F2 preosteoblast cell line was assessed using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide or microtetrazolium assay. The treatment was conducted on days 1, 3, and 7 for observation.The findings indicated that the highest cell viability was observed on day 7, averaging 89.27% at a 0.78% concentration, while the lowest viability was 2.60% at a 100% concentration.These results suggest that RNE is nontoxic to the 7F2 preosteoblast cell line.