Comparisons of antithrombosis, hematopoietic effects and chemical profiles of dried and rice wine-processed Rehmanniae Radix extracts

Abstract

Ethnopharmacological relevance: In traditional Chinese medicine (TCM), Rehmanniae Radix (RR, derived from the root of Rehmannia glutinosa (Gaertn.) DC.) is commonly used as natural medicine for thousands of years, two types including the dried and rice-wine processed RR were used for different clinical purposes respectively, which were the typical case that pharmaceutical effect changed by processing in TCM.

Aim of study: The goal of this study was to investigate the differences in the antithrombosis and hematopoietic effects of extracts of dried and processed RR (DRR and PRR) in vivo, and to explore the chemical basis underlying changes of medicinal properties caused by processing.

Materials and methods: The aqueous extracts of DRR and PRR were prepared. Protective effect of varying doses of different extracts were investigated in type-I carrageenan induced mice tail thrombosis and cyclophosphamide induced myelosuppression model. The chemical composition of DRR and PRR extracts were determined by High Performance Liquid Chromatography coupled with tandem quadrupole time-of-flight Mass Spectrometry (HPLC/Q-TOF-MS).

Results: In antithrombosis activity tests, PRR possessed less ameliorated effects than DRR in the model mouse on body temperature, tail thrombus length and blood flow. Both DRR and PRR had no significant influence on prothrombin time (PT) and activated partial thromboplastin time (APTT), only high dose DRR could decrease the content of fibrinogen (FIB) in plasma. Histological examination of lung tissue suggested that thrombosis was significantly improved in DRR-H group. For myelosuppression model, only PRR could improve peripheral hemogram, both DRR and PRR had hematopoietic effects as demonstrated by their abilities to ameliorate the bone marrow nucleated cells (BMNC) and pathology of bone marrow tissue. The hematopoietic effects of PRR were significantly more potent than that of DRR at the concentration of 9 g/kg. By comparing the chemical composition, we found that iridoid glycosides were decreased and furfural derivatives increased in DRR after processing which may be the chemical mechanism contribute to the differences in efficacy.

Conclusions: According to the results of this research, processing with rice wine for nine cycles significantly reduced antithrombotic effects and enhanced the hematopoietic effects of DRR as demonstrated in model mice. It can scientifically explain the different effect among two types of RR in clinical through the diverse method of processing and usage. Meanwhile, the predicted activity compounds from two types of RR can be potential candidates for the treatment of thrombosis and anemia.

Keywords: Antithrombosis; Dried Rehmanniae Radix; HPLC/Q-TOF-MS; Hematopoietic effect; Processed Rehmanniae Radix.