Introduction: Saffron (Crocus Sativus L) has various pharmacological effects. Gold nanoparticle (GNPs) is involved in cell function and differentiation. In this study the osteogenic effects of Saffron extract and biogenic synthesis gold nanoparticles (GNPs) using Shirazi Thyme (Zataria multiflora) leaves was investigated on differentiation of bone marrow mesenchymal stem cells (BMSCs).

Methods: In this exoerimental study, Wistar rat bone marrow cells were collected and identified. Then these cells were detected by flow cytometry.Cytotoxicity of GNPs and Saffron extract was measured by MTT assay(. Samples were divided to 3 experimental groups and were treated with GNPs (20 µg/ml), Saffron extract (400 µg/ml), and a combination of Saffron extract and GNPs (400 and 20 µg/ml respectively). Differentiation effects were investigated by alizarin red staining after 21 days and alkaline phosphates (ALP) activity after 14 days.

Results: Flow cytometry analysis of surface specific marker confirmed the presence of stem cells. According to the results of MTT assay (P<0.05), the concentrations chosen for combination had not affect cell viability. Alizarin red staining showed Saffron extract and GNPs alone increased osteogenic differentiation. This effect on synergic group was higher. Alkaline phosphates activity in the combined Saffron and GNPs group showed a significant increase compared to the other groups.

Conclusion: According to the findings of this study, synergic used of Saffron extract and GNPs effectively enhance BMSCs differentiation.