Biotransformation and bioaccessibility of active ingredients from Radix Astragali by Poria cocos during solid-state fermentation and in vitro digestion and antioxidant activity evaluation.

Radix Astragali is one of the most famous and frequently used health food supplements and herbal medicines. Among more than 227 components of Radix Astragali, Astragaloside IV (AG IV) is famous functional compound and is commonly used as a quality marker for Radix Astragali. However, the relatively low content of AG IV in Radix Astragali (< 0.04%, w/w) severely limits its application. The purpose of this study is to improve the biotransformation of AG IV and its bioaccessibility during in vitro digestion by Poria cocos solid fermenting Radix Astragali. The optimum fermentation conditions were as follows: Inoculation amount 8 mL; fermentation time 10 d; fermentation humidity 90%. Through fermentation, the content of AG IV was increased from 384.73 to 1986.49 µg/g by 5.16-fold. After in vitro digestion, the contents of genistin, calycosin, formononetin, AG IV, Astragaloside II (AG II) and total flavonoids in fermented Radix Astragali (FRA) of enteric phase II (ENTII) were 34.52 µg/g, 207.32 µg/g, 56.76 µg/g, 2331.46 µg/g, 788.31 µg/g, 3.37 mg/g, which were 2.08-fold, 2.51-fold, 1.05-fold, 8.62-fold, 3.22-fold and 1.50-fold higher than those of control, respectively. The Scanning electron microscopy (SEM) of FRA showed rough surface and porous structure. The DPPH and ABTS radical scavenging rate of FRA were higher than those of control. These results showed that the Poria cocos solid fermentation could increase the content of the AG IV in Radix Astragali and improve the bioaccessibility and antioxidant activity of Radix Astragali, which is providing new ideas for future development and utilization of Radix Astragali.

Ethnobotanical survey of medicinal plants in Gaomi, China.

ETHNOPHARMACOLOGICAL RELEVANCE: The uses of medicinal plants have a long history and become one of the important sources of the health cares in Gaomi City, Shandong Province, China. However, limited studies have been done to identify these medicinal plant species and to scientifically document their associated traditional knowledge. Many species used by indigenous people could potentially represent a novel resource of medicine. The study can aid in further investigations of modern pharmacology and planning of the wild species conservation. AIM OF THE STUDY: The study aimed to investigate and record the medicinal plant taxa and their associated traditional knowledge in Gaomi City, China. MATERIALS AND METHODS: Field study was conducted from March 2018 to May 2019 with 184 residents of Gaomi City. Traditional medicinal plant specimens were collected from the field with the help of these residents and were identified and authenticated in the Herbarium of the School of Pharmacy, Binzhou Medical University. Ethnobotanical knowledge was collected by semi-structured face-to-face interviews. The quantitative data were analyzed by using the informant consensus factor (ICF) method and the number of citations. RESULTS: A total of 181 species belonging to 137 genera and 65 families were collected in Gaomi City. Asteraceae was the predominant family and Fabaceae took the second place. River basins and the southern hills in Gaomi were rich in vegetation. However, the cultivated area of medicinal plants only accounted for 10% of agricultural acreage. The main preparation method was decocting (170, 94.48%) and the most frequent mode of administration was oral (177, 97.97%). The highest numerical ICF value was recorded for treating endocrine, metabolic, and nutritional (ICF: 0.85) conditions. Seven of the medicinal plant species used by the people in Gaomi have not been reported previously in China. Verbena officinalis L. was found in Gaomi City, which is a new distribution record for this species. CONCLUSIONS: People in Gaomi hold valuable knowledge about the use of medicinal plants; however, their knowledge has not been comprehensively documented. The therapeutic uses of the documented medicinal plants will provide a basis for further pharmacological and phytochemical investigations. Additionally, the result of this study indicated that the elder people in Gaomi have more traditional knowledge of plant medicines than the younger ones.

Preparative enrichment and separation of astragalosides from Radix Astragali extracts using macroporous resins.

The enrichment and separation of astragalosides I-IV (AGs I-IV) were studied on eight macroporous resins in the present study. SA-3 resin offered the best adsorption and desorption capacities for AGs I-IV than other resins. The models of adsorption kinetics were investigated in order to elucidate the mechanism of adsorption. The pseudo-second-order model was the better choice than the pseudo-first-order model to describe the adsorption behavior of AGs I-IV onto SA-3 resin. The equilibrium experimental data were well fitted to Langmuir and Freundlich isotherms. SA-3 resin adsorption chromatography tests were carried out to optimize the separation process of AGs I-IV from Radix Astragali extracts. With the optimum parameters for adsorption and desorption, the contents of AGs I-IV were 8.78-, 11.60-, 10.52- and 11.28-fold increased with the recovery yields being 65.88, 90.92, 84.25 and 94.17%, respectively. The preparative enrichment and separation of AGs I-IV from Radix Astragali extracts can be easily and effectively achieved by SA-3 resin adsorption chromatography. The developed methodology can also be referenced for the separation of other active constituents from herbal materials and manufacture of Radix Astragali products.

Enhanced extraction of astragalosides from Radix Astragali by negative pressure cavitation-accelerated enzyme pretreatment.

The optimal conditions for extraction of astragalosides III and IV (AGs III and IV) in Radix Astragali by negative pressure cavitation-accelerated enzyme pretreatment were studied on the basis of a Box-Behnken design and response surface methodology. Experimental results showed that negative pressure, amount of enzyme and incubation temperature were the main factors governing the enzyme pretreatment of Radix Astragali. The optimum parameters were obtained as follows: negative pressure -0.08 Mpa, amount of enzyme 1.48% (w/w of materials) and incubation temperature 45 degrees C. Under the optimal conditions, the maximal extraction yields of AGs III and IV were 0.103 and 0.325 mg/g, which were 41.67% and 65.31% increased as compared to those without enzyme pretreatment, respectively. The effect of negative pressure cavitation and enzyme pretreatment on the structural changes of plant cells was observed by scanning electron microscopy. In conclusion, negative pressure cavitation-accelerated enzyme pretreatment was proved to be environment-friendly and economical, and could be used in secondary metabolites production.