Alisol B 23-acetate-induced HepG2 hepatoma cell death through mTOR signaling-initiated G_1 cell cycle arrest and apoptosis: A quantitative proteomic study

Objective: The present study aimed to investigate the molecular events in alisol B 23-acetate(ABA) cytotoxic activity against a liver cancer cell line.Methods: First, we employed a quantitative proteomics approach based on stable isotope labeling by amino acids in cell culture(SILAC) to identify the different proteins expressed in HepG2 liver cancer cells upon exposure to ABA. Next, bioinformatics analyses through DAVID and STRING on-line tools were used to predict the pathways involved. Finally, we applied functional validation including cell cycle analysis and Western blotting for apoptosis and mTOR pathway-related proteins to confirm the bioinformatics predictions.Results: We identified 330 different proteins with the SILAC-based quantitative proteomics approach. The bioinformatics analysis and the functional validation revealed that the mTOR pathway, ribosome biogenesis, cell cycle, and apoptosis pathways were differentially regulated by ABA. G1 cell cycle arrest, apoptosis and mTOR inhibition were confirmed.Conclusions: ABA, a potential mTOR inhibitor, induces the disruption of ribosomal biogenesis. It also affects the mTOR-MRP axis to cause G1 cell cycle arrest and finally leads to cancer cell apoptosis.

A UFLC/MS/MS method for simultaneous quantitation of alisol A and alisol B 23-acetate from Alisma orientale (Sam.) Juz. in rat plasma

A sensitive and reliable ultra fast liquid chromatography tandem mass spectrometry(UFLC-MS/MS)method has been developed and validated for simultaneous quantitation of alisol A and alisol B 23-acetate from Alisma orientale(Sam.)Juz.in rat plasma using diazepam as an internal standard(IS).The plasma samples were extracted by liquideliquid extraction with methyl tert-butyl ether and separated on a Venusil MP C18 column(100 mm×2.1 mm,3.0 mm)(Venusil,China)using gradient elution with the mobile phase consisting of methanol and 0.1%acetic acid in water at a flow rate of 0.4 ml/min.The two analytes were monitored with positive electrospray ionization by multiple reaction monitoring mode(MRM).The lower limit of quantitation was 5.00 ng/ml for alisol A and 5.00 ng/ml for alisol B 23-acetate.The calibration curves were linear in the range of 5.00 e2500 ng/ml for alisol A and 5e2500 ng/ml for alisol B 23-acetate.The mean extraction recoveries were above 63.8%for alisol A and 68.0%for alisol B 23-acetate from biological matrixes.Both intra-day and inter-day precision and accuracy of analytes were well within acceptance criteria(15%).The validated method was successfully applied to the pharmacokinetic study of alisol A and alisol B 23-acetate in rat plasma after oral administration of alcohol extract of Alismatis Rhizoma.

Alisol B 23-acetate promotes white adipose tissue browning to mitigate high-fat diet-induced obesity by regulating mTOR-SREBP1 signaling

Objective Obesity is a global health concern with management strategies encompassing bariatric surgery and anti-obesity drugs;however,concerns regarding complexities and side effects persist,driving research for more effective,low-risk strategies.The promotion of white adipose tissue(WAT)browning has emerged as a promising approach.Moreover,alisol B 23-acetate(AB23A)has demonstrated efficacy in addressing metabolic disorders,suggesting its potential as a therapeutic agent in obesity management.Therefore,in this study,we aimed to investigate the therapeutic potential of AB23A for mitigating obesity by regulating metabolic phenotypes and lipid distribution in mice fed a high-fat diet(HFD).Methods An obesity mouse model was established by administration of an HFD.Glucose and insulin metabolism were assessed via glucose and insulin tolerance tests.Adipocyte size was determined using hematoxylin and eosin staining.The expression of browning markers in WAT was evaluated using Western blotting and quantitative real-time polymerase chain reaction.Metabolic cage monitoring involved the assessment of various parameters,including food and water intake,energy metabolism,respiratory exchange rates,and physical activity.Moreover,oil red O staining was used to evaluate intracellular lipid accumulation.A bioinformatic analysis tool for identifying the molecular mechanisms of traditional Chinese medicine was used to examine AB23A targets and associated signaling pathways.Results AB23A administration significantly reduced the weight of obese mice,decreased the mass of inguinal WAT,epididymal WAT,and perirenal adipose tissue,improved glucose and insulin metabolism,and reduced adipocyte size.Moreover,treatment with AB23A promoted the expression of browning markers in WAT,enhanced overall energy metabolism in mice,and had no discernible effect on food intake,water consumption,or physical activity.In 3T3-L1 cells,AB23A inhibited lipid accumulation,and both AB23A and rapamycin inhibited the mammalian target of rapamycin-sterol regulatory element-binding protein-1(mTOR-SREBP1)signaling pathway.Furthermore,3-isobutyl-1-methylxanthine,dexamethasone and insulin,at concentrations of 0.25 mmol/L,0.25μmol/L and 1μg/mL,respectively,induced activation of the mTOR-SREBP1 signaling pathway,which was further strengthened by an mTOR activator MHY1485.Notably,MHY1485 reversed the beneficial effects of AB23A in 3T3-L1 cells.Conclusion AB23A promoted WAT browning by inhibiting the mTOR-SREBP1 signaling pathway,offering a potential strategy to prevent obesity.

泽泻三萜成分的研究Ⅲ

本文又从四川产泽泻中分离、鉴定了 5个三萜成分 ,其中alisolE 2 4 acetate(Ⅱ )、13 ,17 epoxyal isolA 2 4 acetate(Ⅳ )为新化合物 ,其它已知成分是alisolE 2 3 acetate(Ⅰ )、13β ,17β epoxyalisolA(Ⅲ )、11 deoxyalisolA(Ⅴ )。