The six polysaccharide fractions were prepared by chromatographic procedure from the hot water extractsof the aboveground parts of Astragalus membranaceus. These six polysaccharides from aboveground parts of Astragalusmembranaceus Bunge were tested for gut-mucosal immune activity and acute toxicity. In a view of molecular weight, the sixfractions were estimated to be 75000, 88000, 129000 and 345000 Da, respectively. Component sugar analysis indicated thatthese fractions were mainly consisted of galactose (46.3~11.8%) and arabinose (35.4~9.9%) in addition to glucose,rhamnose, fucose, arabinose, xylose, mannose, glucuronic acid and galacturonic acid. Among the six major purifiedpolysaccharides, AMA-1-b-PS2 showed highest bone merrow cell proliferation and lymphocyte of Peyer's patch stimulatingactivity. It may be concluded that intestinal immune system modulating activity of aboveground parts from Astragalusmembranaceus Bunge is caused by polysaccharides having a polygalacturonan moiety with neutral sugars such as arabinoseand galactose. In single oral dose toxicity study, no differences were observed between control and treated groups in clinicalsigns. The results indicated that lethal dose 50 (LD50) of water extracts from Astragalus membranaceus-aboveground partswas found to be higher than 5000㎎/㎏/day in this experiment. From the above results, we may suggest that Astragalusmembranaceus-aboveground parts might have useful as a safe material for functional food and pharmaceutics.

Pharmacological studies and clinical practices have indicated that Radix Astragali, a dried root of Astragalusmembranaceus possesses a lot of biological activities, including antioxidant, hepatoprotective, anti-diabetic, tonic, diuretic,antimicrobial, antiviral, and immunological activities. These biological activities approved by the modern pharmacologicalstudies are mainly due to the constituents of Astragalus membranaceus including polysaccharides, saponins, flavonoids,amino acids, and trace elements. In resent, the main constituents in the root part showing a lot of biological activities hasbeen isolated also from the aboveground parts such as leaves and sprouts in our laboratory. However, the safety evaluationfor the aboveground parts of Astragalus membranaceus should be checked before expanding their application as one of food.In the study, a 90-day rat oral gavage study has been conducted with the extracts from Astragalus membranaceus-above-ground parts at doses of 1000, 3000, and 5000㎎/㎏/day. The following endpoints were evaluated: clinical observations, bodyweight, gross and microscopic pathology, clinical chemistry, and hematology. Based on the analysis of these endpoints, it wasestimated that NOEL (no observed effect level) for male rats and NOAEL (no observed adverse effect level) for female ratsare 5000㎎/㎏/day of the water-extracts from Astragalus membranaceus-aboveground parts.

This study was conducted to determine the contents of phenolic compounds and astragalosides in Astragalus membranaceus. Between the phenolic compound groups, flavonoids compounds (51.13%) had higher average concentrations than the phenolic acids groups. Among the 30 phenolic compounds, quercetin (353.11μg g-1) provided the highest concentrations. According to different cultivation year, 3-year-cultivated Astragalus (2612.57μg g-1) showed the highest concentrations of phenolic compounds. According to different harvest days, 6/5 harvesting Astragalus (2615.80μg g-1) showed the highest concentrations of phenolic acids. Comparison between the top and subterranean parts of harvested Astragalus plants cultivated for 2 years, 3 years, and 5 years showed big difference of total phenolic compounds in concentrations. Further, the top part had higher amounts of the total phenolic compounds than the subterranean part among all Astragalus. This tendency was similar to those of the top root and lateral root. The concentration of the phenolic compounds in the top root was higher than that of the lateral root.