Preventing Neurons and Glial Cells Destruction in Substantia Nigra Pars Compacta and Striatum Using St. John's Wort...

St. John's wort (Hypericum perforatum) has been used for centuries as a medicinal plant to remedy external disorders such as burns and wounds, as well as internal disorders such as nerve pain, anxiety, and depression. Bone marrow mesenchymal stem cells (BMSCs) are a heterogeneous population of pluripotent stromal cells that can differentiate into a variety of cell types. The aim of the study was to individually and combinationally investigate the effect of whole extract and stem cells on Parkinson's disease. Furthermore, using a new method for stem cells transplantation to enhance cell integration into substantia nigra pars compacta (SNC) and striatum.

In the study, 63 adult male Wistar rats were classified, and among them, treatment groups received 20 mg/kg extract (intraperitoneally; 28 days) and nearly 1 million (mean of 936 × 10³) mesenchymal stem cells through cisterna magna, either individually or in combination.

Histological evaluations revealed that there has been a sharp rise in neurons in both ventral and dorsal striatum in the pretreatment plus cell group (p < 0.001). Regarding neurons in SNC area, quantitative investigations via Nissl and immunohistochemistry staining showed significant differences between the lesion group and groups receiving pretreatment, treatment plus cells, and pretreatment plus cells (p < 0.001). According to evidence, there are some communications between St. John's wort and stem cells that have led to navigate stem cells to immigrate and deploy within striatum.

The study found that both H. perforatum extract and BMSCs can help preserve dopaminergic neurons and glial cells during which combination therapy demonstrates synergy as an indicator. St. John's is a natural preserver and appears to function as a neuroprotective agent and facilitate the navigation and integration of stem cells; consequently, it keeps surviving both neurons and glial cells against pathogens and destructive environmental factors and has a potential to help us and Parkinson's patients.