Metabolites of curculigoside in rats and their antiosteoporotic activities in osteoblastic MC3T3-E1 cells.

Curculigoside isolated from Curculiginis Rhizoma exhibits a wide spectrum of bioactivities. In this study, a high performance liquid chromatography/quadrupole time-of- flight tandem mass spectrometry (UHPLC/Q-TOF MS) method was employed to investigate the metabolism of curculigoside in rats. Plasma, bile, urine, feces and 17 tissues were collected from rats after a single PO dose of curculigoside at 100mg/kg and prepared through methanol precipitation. Parent compound and a total of 7 metabolites were detected and identified based on their retention time and fragment ions. Metabolic pathways of curculigoside in rats include hydrolysis, demethylation and glucuronidation. Exposure of major metabolite M2 in plasma and it's antiosteoporotic activity in osteoblastic MC3T3-E1 cells were studied to help understand that curculigoside assimilates less but works more.

Pharmacokinetic and tissue distribution profile of curculigoside after oral and intravenously injection administration in rats by liquid chromatography-mass spectrometry.

Curculigoside has an extensive pharmacological activity, including estrogen-like, improving sexual behavior, antiosteoporotic, antioxidant, immunomodulatory and neuroprotective effects. However, few investigations have been conducted about the pharmacokinetics and tissue distribution of curculigoside to better understand its behavior and action mechanism in vivo. Thus, a sensitive and reliable liquid chromatography with mass spectrometry (HPLC-MS) method was established and validated for the quantification of curculigoside in rat plasma and tissue samples. Biological samples were processed with methanol precipitation, and naringin was used as the internal standard. Chromatographic separation was performed on an Agilent XDB-C18 chromatography column (3.0mm×50mm, 1.8µm) with a mobile phase consisting of acetonitrile and 0.1% formic acid. Quantification was performed by selected ion monitoring with m/z 511.1 [M+HCO2](-) for curculigoside and m/z 579.1 [M-H](-) for the internal standard. The validated method was successfully applied to the pharmacokinetic and tissue distribution study of curculigoside in rats. Non-compartmental pharmacokinetic parameters indicated that curculigoside had rapid distribution, extensive tissue uptake, and poor absorption into systemic circulation. The values of absolute bioavailability were 0.38%, 0.22% and 0.27% for oral doses of 100, 200 and 400mg/kg, respectively. The results of the tissue distribution study suggested that curculigoside was distributed into the heart, lung, spleen, intestine, stomach, kidney, thymus, liver, brain, testis, and bone marrow after oral administration of 150mg/kg. In conclusion, the present study may provide a material basis for study of the pharmacological action of curculigoside, and meaningful insights into further study on clinical application.

[Research progress of phytoestrogens-like chemical constituents in natural medicines].

Phytoestrogens, which can bind with estrogen receptor and produce estrogen-like effects, are a kind of nonsteroidal compound in plant. Phytoestrogens chemically include isoflavones, coumarins, lignans and other compounds. Phytoestrogens are selective estrogen receptor modulator, and have therapeutical effects on breast cancer, prostate cancer, cardiovascular disease, menopausal symptoms, osteoporosis and other disease, however, do not produce stimulatory hyperplasia effects on uterus, mammary glands and other tissues and organs with positive estrogen receptor. Long-term exposure or excessive use of phytoestrogens maybe affects male reproductive system and hematopoietic function of fetus. Some questions need to be further studied, such as evaluation criteria on biological activity, adverse effects, and action mechanism of phytoestrogen. This review covers plant sources, chemical structure, pharmacological activity and safety of phytoestrogens. It will provide a useful reference for intensive research and rational utilization the phytoestrogens.