Background: With regards to the high potential of medicinal plants in the production of biopharmaceuticals, one can rely on the promising prospect of insulin production via plant resources. Objectives: This study was conducted with the aim of using plant extract for insulin-producing cells. Methods: This was a quasi-experimental study using critical case sampling. Six samples were gathered from the umbilical cord (Wharton's jelly) in a governmental university affiliated hospital, Sari, Iran in 2017 after successful isolation of mesenchymal stem cells. Initially, Nigella sativa seeds extraction was performed to prepare the extract for cellular differentiation. Next, dithizone (DTZ) staining was used to evaluate insulin production, and insulin level was examined by the enzyme-linked immunosorbent assay (ELISA). Data were analyzed was analyzed with the SPSS version 16 software using independent sample t-test.