BACKGROUND: Rehmannia glutinosa (Gaertn.) DC. (RG) is a widely used herb for clearing heat and cooling the blood. Polysaccharides from Rehmannia glutinosa (Gaertn.) DC. (RGPs) have a variety of biological activities, including antioxidation, hypoglycemia, immune enhancement, hematopoiesis promotion, and antianxiety.
OBJECTIVE: This review provides up-to-date and comprehensive information on the extraction and separation methods, structural characteristics, and pharmacological activities of RGPs. A more in-depth study on the structure and clinical pharmacology of the RGPs was investigated. To further explore the pharmacological effects of RGPS, and lay a foundation for the safe clinical application and expansion of application scope.
METHODS: Use Google Scholar, Scifinder, PubMed, Springer, Elsevier, Wiley, Web of Science and other online database search to collect the literature on extraction, separation, structural analysis and pharmacological activity of RGPs published before December 2022. The key words are \"extraction\", \"isolation\", \"purification\" and \"pharmacological action\" and \"Rehmanniae polysaccharide\".
RESULTS: Rehmannia glutinosa has been widely used in the treatment of diabetes since ancient times, and is known as one of the \"Four Sacred Medicines\" for the treatment of diabetes, along with Ginseng, Psidium Guajava and Pueraria Mirifica. The active ingredients of Rehmannia glutinosa that have been studied more in the treatment of diabetes are Rehmannia glutinosa polysaccharide and Rehmannia glutinosa oligosaccharide. The content of polysaccharides varies due to different extraction methods, and separation and purification methods. RGPs have a wide range of pharmacological activities, including antitumor, immunomodulatory, neuroprotective effect, hypoglycemic activity, cardioprotective and antioxidant activities. These pharmacological properties lay a foundation for the treatment of tumors, inflammation, hyperglycemia, myocardial ischemia, oxidative stress and other diseases with RGPs.
CONCLUSIONS: Based on its effects of promoting hematopoiesis, antitumor and enhancing immunity, RGPs have been clinically applied in the treatment of chronic aplastic anemia and esophageal cancer, but other effects of RGPs have not been reflected in the clinical practice. In the future, more in-depth research can be conducted on the molecular structure analysis, toxicity, side effects and clinical pharmacological effects of RGPs to further explore the pharmacological effects of RGPs and to lay the foundation for safe clinical application and expansion of application scope.

OBJECTIVE: This study was a review of the literature published on the efficacy of Rehmanniae Radix to obtain information to provide both a foundation for its clinical use and directions for future studies.
METHODS: This study selected 30 publications registered to databases or published in Korea by March 13, 2017, by searching electronic journal databases, i.e., NDSL, OASIS, RISS, and KISS, in order to review the efficacy of Rehmanniae Radix. The search was conducted using the keywords \'\', \'\', \'Rehmannia Glutinosa\', and \'Rehmanniae Radix\', and the search results were compiled and analyzed.
RESULTS: The selected publications included antioxidant effects (12 publications), data involving blood glucose reduction (4 publications), effects on the autonomic nervous system (3 publications), and effects on the human body (11 publications).
CONCLUSIONS: The results of this literature review indicate that Rehmanniae Radix is effective in treating patients with various inflammatory and metabolic diseases, such as high blood pressure and diabetes. Based on these results, we believe that Rehmanniae Radix can be used effectively to treat patients with such diseases.