Shilajit Boosts Osteogenic Ability of Mesenchymal Stem Cells for Regeneration of Rat Bone Defect

Purpose Mesenchymal stem cell (MSC) therapy and using herbal extracts such as Shilajit have shown promising results in bone fracture repair. The purpose of this study was to discover the synergistic effects of human adipose–derived MSCs (ASCs) and Shilajit-loaded alginate (Alg) on rat tibia bone defect repair. Methods A 7-mm defect was made in right tibia of seventy-five rats, and then, they were treated with Shilajit/Alg/ASCs, Alg/ASCs, Shilajit/Alg, Alg, and untreated control groups for 2 and 4 weeks. Bone formation was assayed via radiology, morphometrical analyses, and biomechanical tests. Results A significant lower doubling time was detected in the Shilajit-treated ASCs than in the untreated group ( P =0.016). X-ray photography showed a higher bone density in the groups treated with Shilajit/Alg/ASCs, ASCs, or Shilajit than in the alginate and untreated groups after 4 weeks. Morphometric estimations showed predominant synergistic effects of Shilajit and ASCs on increasing bone area relative to the groups received either ASCs ( P = 0.008), Shilajit ( P = 0.004), Alg, or remained untreated ( P < 0.0001) at week 2. Also, a highest number of osteoblasts and osteocytes were present in the Shilajit/Alg/ASC-treated group than all of the other groups ( P < 0.0001). Mechanical strength of the tibia significantly elevated in the Shilajit/Alg/ASCs compared to the Alg/ASCs ( P < 0.05), Shilajit/Alg ( P < 0.01), Alg, and untreated groups ( P < 0.001). Trichrome Masson staining revealed that collagen deposition was higher in the Shilajit/Alg/ASCs compared to other groups at week 2. Conclusion The combination of ASCs, Shilajit, and alginate can accelerate bone tissue regeneration and provide a suitable approach for cell therapy of bone defects. Lay Summary Reports In this study, we try to assess the efficacy of a combination of adipose-derived stem cells (ASCs) and Shilajit and alginate on bone defect repair in rat model. We also aim to evaluate the effectiveness of Shilajit as a natural substance for bone defect repair.