Extraction Optimization of Astragaloside IV by Response Surface Methodology and Evaluation of Its Stability during Sterilization and Storage

Abstract

Radix Astragali is referred to as a variety of food-medicine herb, and it is commonly applied as Traditional Chinese Medicine (TCM). However, it is extremely difficult to extract its bio-active compounds (astragaloside IV) and apply it in food processing efficiently, which restricts its practical applications. In this study, the conditions required for the extraction of astragaloside IV were optimized by following the response surface methodology. More specifically, ammonia with a concentration of 24% was used as an extracting solvent, the solid–liquid ratio was 1:10 (w:v); the Radix Astragali was soaked at 25 °C for 120 min in advance and then stirred at 25 °C for 52 min (150 rpm) to extract astragaloside IV. This method promoted the transformation of other astragalosides into astragaloside IV and replaced the traditional approach for extraction, the solvent reflux extraction method. The yield of astragaloside IV reached the range of 2.621 ± 0.019 mg/g. In addition, the stability of astragaloside IV was evaluated by detecting its retention rate during sterilization and 60-day storage. As suggested by the results, the astragaloside IV in acidic, low-acidic, and neutral solutions was maintained above 90% after sterilization (95 °C and 60 min) but below 60% in an alkaline solution. High temperature and short-term sterilization approach is more appropriate for astragaloside IV in an alkaline solution. It was also found out that the astragaloside IV obtained using our method was maintained over 90% when stored at room temperature (25 °C), and there was no significant difference observed to low temperature (4 °C) in solutions regardless of acidity.

Current Progress on Neuroprotection Induced by Artemisia, Ginseng, Astragalus, and Ginkgo Traditional Chinese Medicines for the Therapy of Alzheimer’s Disease

“…Astragalus membranaceus is a medicinal herb from the Fabaceae/Leguminosae family commonly used in several herbal formulations of TCM and containing complex bioactive components, including flavonoids, saponins, and polysaccharides [ 85 ]. Astragaloside IV (AS-IV) ( Figure 1(c) ), a small molecular saponin purified from Astragalus membranaceus [ 86 ], is the main active ingredient and is well-known for its multiple peripheral pharmacological effects and central nervous system neuroprotective effects [ 87 – 89 ], with evidences in animal models indicating its therapeutic potential for AD [ 90 – 92 ] and Parkinson's disease (PD) [ 93 – 95 ]. For example, Costa et al performed a systematic review on the neuroprotective effects induced by AS-IV in experimental models of neurological disorders covering the years between 2007 and 2017 and pointed to the fact that administration of AS-IV can improve behavioral and neurochemical deficits largely due to its antioxidant, antiapoptotic, and anti-inflammatory properties [ 90 ].…”

RRLC-QTOF/MS-Based Metabolomics Reveal the Mechanism of Chemical Variations and Transformations of Astragali Radix as a Result of the Roasting Process

“…Rapid-resolution liquid chromatography combined with quadrupole time-of-flight mass spectrometry (RRLC-Q/TOF-MS) has become preferred analytical choices in plant metabolomics research because of their unsurpassed sensitivities and high resolutions ( Klevorn and Dean, 2017 ; Chai et al, 2019 ). Previous studies have elucidated the composition variations of AR under different conditions, such as the conversion of malonyl flavonoids into glycosides during solvent heating extraction ( Zheng et al, 2019 ), as well as the transformation of astragaloside Ⅳ during sterilization and storage ( Xu et al, 2021 ). But are these changes similar to or different from the changes occurring during the roasting process?…”