Hepatoprotective effects of Astragalus kahiricus root extract against ethanol-induced liver apoptosis in rats

Study on the Biotransformation and Activities of Astragalosides from Astragali Radix In Vitro and In Vivo

Astragalosides (AGs), as one of the main active ingredients in Astragali Radix (AR), have a series of biological activities. Previous studies have only qualitatively identified the metabolites of AGs in AR, resulting in a lack of quantification. In the present study, the original material was selected from 12 origins based on the levels of 4 AGs by high-performance liquid chromatography (HPLC). The prototype components and metabolites of total AGs (TAGs) in feces, urine, and plasma samples of rats were thoroughly screened and characterized by ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS). The fermentation reaction and metabolites were verified by human fecal TAG fermentation in vitro. The metabolites of AG I, II, and IV transformed by human feces at different times were identified using UHPLC-HRMS, and the partial metabolites were quantified by HPLC. Furthermore, the anti-inflammatory and antioxidant activities of the metabolites were evaluated based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells in vitro. In total, 13 AGs and 170 metabolites were identified in TAGs as well as in the plasma, urine, and feces of Sprague-Dawley (SD) rats by UHPLC-HRMS, including 28, 36, and 170 metabolites in the plasma, urine, and feces, respectively. The metabolites included the products of deglycosylation, demethylation, hydroxylation, glucuronidation, sulfation, and cysteine-binding reactions. Moreover, the TAG fermentation results in vitro showed great similarity. The human fecal incubation experiments for AG I, II, and IV demonstrated that the metabolic reaction of TAGs mainly occurred in intestinal feces and that deglycosylation, demethylation, and hydroxylation were the main pathways of their metabolism. HPLC quantitative analysis of the transformation solution at different time points showed that AGs were transformed into secondary glycosides [cycloastragenol-6-glucoside (CAG-6-glucoside)] and aglycones [cycloastragenol (CAG)] through a deglycosylation reaction. Analysis of the pharmacological activity showed that the anti-inflammatory and antioxidant activities of the metabolites were associated with the levels of the corresponding aglycones. Further, metabolic profiles of the TAGs were constructed. Overall, this study revealed the metabolic process of AGs in the intestine, providing guidance for the metabolism and pharmacological effects of other saponins.

Alleviation of liver cirrhosis and associated portal-hypertension by Astragalus species in relation to their UPLC-MS/MS metabolic profiles: a mechanistic study

Liver cirrhosis is a late-stage liver disease characterized by excessive fibrous deposition triggering portal-hypertension (PH); the prime restrainer for cirrhosis-related complications. Remedies that can dually oppose hepatic fibrosis and lower PH, may prevent progression into decompensated-cirrhosis. Different Astragalus-species members have shown antifibrotic and diuretic actions with possible subsequent PH reduction. However, A.spinosus and A.trigonus were poorly tested for eliciting these actions. Herein, A.spinosus and A.trigonus roots and aerial parts extracts were subjected to comprehensive metabolic-fingerprinting using UHPLC-MS/MS resulting in 56 identified phytoconstituents, followed by chemometric untargeted analysis that revealed variable metabolic profiles exemplified by different species and organ types. Consequently, tested extracts were in-vivo evaluated for potential antifibrotic/anticirrhotic activity by assessing specific markers. The mechanistic prospective to induce diuresis was investigated by analyzing plasma aldosterone and renal-transporters gene-expression. Serum apelin and dimethylarginine-dimethylaminohydrolase-1 were measured to indicate the overall effect on PH. All extracts amended cirrhosis and PH to varying extents and induced diuresis via different mechanisms. Further, An OPLS model was built to generate a comprehensive metabolic-profiling of A.spinosus and A.trigonus secondary-metabolites providing a chemical-based evidence for their efficacious consistency. In conclusion, A.spinosus and A.trigonus organs comprised myriad pharmacologically-active constituents that act synergistically to ameliorate cirrhosis and associated PH.

Astragalus Polysaccharides and Saponins Alleviate Liver Injury and Regulate Gut Microbiota in Alcohol Liver Disease Mice

Astragalus, a medical and edible plant in China, shows several bioactive properties. However, the role of astragalus in attenuating alcoholic liver disease (ALD) is less clear. The objective of this project is to investigate the improving effect of astragalus saponins (AS) and astragalus polysaccharides (AP), which are the two primary constituents in astragalus on hepatic injury induced by alcohol, and the potential mechanisms of action. Different doses of AS (50 and 100 mg/kg bw) and AP (300 and 600 mg/kg bw) were orally given to alcohol-treated mice for four weeks. The results demonstrated that both AP and AS could reverse the increase of the levels of TC, TG, FFA, and LDL-C in serum, and the decrease of serum HDL-C content, as well as the elevation of hepatic TC and TG levels induced by alcohol. The activities of AST, ALT, ALP, and γ-GT in ALD mice were raised after AP and AS supplementation. The antioxidant markers (SOD, CAT, GSH, and GSH-Px) were obviously augmented and the pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) and hepatic histological variations were alleviated by AP and AS, which was in line with the levels of oxidative stress-associated genes (Keap1, Nfe2l2, Nqo1, and Hmox1) and inflammation-associated genes (Tlr4, Myd88 and Nfkb1). In addition, AS exerted a more efficient effect than AP and the results presented dose proportionality. Moreover, AS and AP could modulate the intestinal microbiota disturbance induced by alcohol. Overall, AS and AP administration could ameliorate lipid accumulation in the serum and liver, as well as hepatic function, oxidative stress, inflammatory response, and gut flora disorders in mice as a result of alcohol.

Astragalus species: Insights on its chemical composition toward pharmacological applications

Astragalus L. is widely distributed throughout the temperate regions of Europe, Asia, and North America. The genus is widely used in folk medicine and in dietary supplements, as well as in cosmetics, teas, coffee, vegetable gums, and as forage for animals. The major phytoconstituents of Astragalus species with beneficial properties are saponins, flavonoids, and polysaccharides. Astragalus extracts and their isolated components exhibited promising in vitro and in vivo biological activities, including antiaging, antiinfective, cytoprotective, antiinflammatory, antioxidant, antitumor, antidiabesity, and immune-enhancing properties. Considering their proven therapeutic potential, the aim of this work is to give a comprehensive summary of the Astragalus spp. and their active components, in an attempt to provide new insight for further clinical development of these xenobiotics. This is the first review that briefly describes their ethnopharmacology, composition, biological, and toxicological properties.

Protective effects of Astragalus kahiricus root extract on ethanol-induced retrograde memory impairments in mice

Introduction: Alzheimer’s disease (AD) is a neurodegenerative disorder that has no definite cure. Currently, there is great interest in using plant-based medicines to treat AD. In the present study, the neuroprotective effects of Astragalus kahiricus root extract were evaluated in a retrograde amnesia model. Methods: Male albino mice were given four training sessions in the Morris water maze for seven consecutive days. Treated groups were administered A. kahiricus (25 or 50 mg/kg, i.p.) before ethanol (3.5 gm/kg, i.p) injection. All animals were given a test session in the Morris water maze apparatus. Acetylcholinesterase activity and the levels of oxidative stress biomarkers were also measured. Results: Memory impairment was observed, after ethanol administration, as increased escape latency time and path length travelled by the animals. On the other hand, A. kahiricus significantly reduced both escape latency time and path length. In addition, the extract demonstrated an inhibitory effect on acetylcholinesterase activity and total nitrite level. Moreover, A. kahiricus significantly increased the level of reduced glutathione in mice brain. Conclusion: This study demonstrated the potential behavioural and biochemical neuroprotective properties of A. kahiricus root extract, which might further be considered an important candidate for the treatment of AD.

Metabolomics combined with network pharmacology exploration reveals the modulatory properties of Astragali Radix extract in the treatment of liver fibrosis

Background

Astragali Radix (AR) is widely-used for improving liver fibrosis, but, the mechanism of action has not been systematically explained. This study aims to investigate the mechanism of AR intervention in liver fibrosis based on comprehensive metabolomics combined with network pharmacology approach.

Materials and methods

UPLC–Q-TOF/MS based metabolomics technique was used to explore the specific metabolites and possible pathways of AR affecting the pathological process of liver fibrosis. Network pharmacology analysis was introduced to explore the key targets of AR regarding the mechanisms on liver fibrosis.

Results

AR significantly reduced the levels of ALT, AST and AKP in serum, and improved pathological characteristics. Metabolomics analysis showed that the therapeutic effect of AR was mainly related to the regulation of nine metabolites, including sphingosine, 6-keto-prostaglandin F1a, LysoPC (O-18:0), 3-dehydrosphinganine, 5,6-epoxy-8,11,14-eicosatrienoic acid, leukotriene C4, taurochenodesoxycholic acid, LysoPC (18:1 (9Z)) and 2-acetyl-1-alkyl-sn-glycero-3-phosphocholine. Pathway analysis indicated that the treatment of AR on liver fibrosis was related to arachidonic acid metabolism, ether lipid metabolism, sphingolipid metabolism, glycerophospholipid metabolism and primary bile acid biosynthesis. Validation of the key targets by network pharmacology analysis of potential metabolic markers showed that AR significantly down-regulated the expression of CYP1B1 and up-regulated the expression of CYP1A2 and PCYT1A.

Conclusion

Metabolomics combined with network pharmacology was used for the first time to clarify that the treatment of AR on liver fibrosis, which is related to the regulation of arachidonic acid metabolism and ether lipid metabolism by modulating the expression of CYP1A2, CYP1B1 and PCYT1A. And the integrated approach can provide new strategies and ideas for the study of molecular mechanisms of traditional Chinese medicines in the treatment of liver fibrosis.

Quantification of complanatoside A in rat plasma using LC-MS/MS and its application to a pharmacokinetic study

Complanatoside A is a flavonol glycoside isolated from Astragalus complanatus, and currently it is used as a quality control index for A. complanatus in the 2010 edition of the Chinese Pharmacopoeia. For the first time, a simple and sensitive LC-MS/MS method was developed for the determination of complanatoside A in rat plasma over the range of 2.3-575 ng/mL. Complanatoside A was extracted from plasma by a protein precipitation procedure, separated by LC and detected by MS/MS in positive electrospray ionization mode. The method was validated for selectivity, carryover, sensitivity, linearity, extraction recovery, matrix effect, accuracy, precision and stability studies. The lower limit of quantification was established at 2.3 ng/mL. Intra- and inter-day precisions (LLOQ, low-QC, med-QC and high-QC) were <7.9%, and accuracies were between 94.0 and 105.1%. Matrix effect was acceptable (97.9-103.0%) and extraction recovery was reproducible (88.5-94.4%). Complanatoside A was stable in the investigated conditions. The method was applied to the pharmacokinetics of complanatoside A in rats. Copyright © 2015 John Wiley & Sons, Ltd.