Aging is a physiological and multifactorial biological process of functional decline in any living organism. Telomere shortening, high levels of reactive oxygen species (ROS), and cellular senescence are the primary physiological changes that accompany aging. While there has been an increase in human life expectancy in recent decades, there has not been a concomitant increase in healthy aging. Degenerative diseases, including musculoskeletal disorders such as osteoporosis and osteoarthritis, have been found to be directly linked to aging. Age-related degenerative diseases are devastating diseases that cause millions of deaths worldwide each year and place an economic and psychological burden on society. Due to the ever-increasing number of patients, there is a huge demand for novel therapeutic approaches to treat degenerative diseases. Two main approaches are at the forefront of technology for the treatment of degenerative diseases: stem cell transplantation (regenerative medicine) and monoclonal antibody-based therapy. Indeed, it is well known that there is a strong correlation between disease pathology and telomeres. In fact, the possible therapeutic effects of telomerase activation have been evaluated in diverse backgrounds to cure and prevent various diseases. Within the scope of this thesis, we aim to investigate the effects of telomerase activator novel molecules from Astragalus sp., obtained in our previous studies by biotransformation of cycloastragenol (CG) via the plant’s endophytic fungi on the health span/lifespan of mesenchymal stem cells (MSCs) during in vitro expansion and their osteogenic differentiation. Additionally, the efficacy of these compounds was investigated in the monoclonal antibody (mAb) production process in terms of mAb productivity. Based on the outcomes of the study, novel telomerase activators deriving from natural resources of our country have significant potential in stem cell research, thus regenerative medicine, since promising results were obtained for the clinical use of these novel molecules. Our data also suggest that molecules simultaneously promote osteogenic differentiation and telomerase activation