Total Steroidal Saponins Research Articles

The total saponins from Chinese onion exert pronounced anti-hypercholesterolaemia activity in mice

AbstractChinese onion (Allium chinense G. Don) is an edible vegetable as well as a traditional Chinese medicine. It is rich in steroidal saponins and possesses broad health benefits. In this study, the optimal extraction protocol of the total saponins from Chinese onion (ACS) was explored, and the content of the total steroidal saponins in ACS reached 56.62%. Network pharmacology was applied to predict the related signalling pathways and targets between the main phytochemicals in ACS and hypercholesterolaemia. Enrichment analysis showed that ACS might intervene hypercholesterolaemia through the PI3K-Akt signalling pathway. Meanwhile, cholesterol-lowering effects were verified by ACS intervention in high-cholesterol diet-induced hypercholesterolaemia in Kunming mice. Compared with the model group, the TC and LDL-C levels of mice were decreased and the HDL-C level increased significantly after administration of ACS at a dose of 200 mg kg−1 day−1. The body weight gain, liver index, and atherosclerosis index all decreased dramatically. ACS could significantly reduce the fat content in the liver and reduce the number of fat droplets from the haematoxylin and eosin (H&E) staining of mouse liver. The immunohistochemical staining indicated that ACS could up-regulate the expression of PI3K protein in the liver, thus playing an anti-hypercholesterolaemic role. This study indicated that ACS exhibited significant therapeutic and preventive effects on hypercholesterolaemia, and exerted anti-hypercholesterolaemia through the PI3K-Akt signalling pathway.

Solanum nigram - A Potential Medicinal Herb

This plant commonly referred to as "Black nightshade," Solanum nigrum Linn. (Solanaceae) it is widely used in traditional medicine in India and other parts of the world to treat liver conditions, chronic skin conditions (such as psoriasis and ringworm), inflammatory conditions, painful periods, fevers, diarrhoea, eye diseases, hydrophobia, etc. It has been discovered that Solanum nigrum contains compounds with anti-tumor action, such as total alkaloids, steroid alkaloids, steroidal saponins, and glycoprotein. The herb is utilised as a hepatoprotective in Indian traditional medicine. This plant have potential role as a multipurpose medicinal agent, we have investigated the phyto-pharmacological properties of the plant and compiled its comprehensive pharmacological uses in this review paper.

Total steroidal saponins from black nightshade (Solanum nigrum L.) overcome tumor multidrug resistance by inducing autophagy-mediated cell death in vivo and in vitro.

Multiple drug resistance (MDR) often occurs after prolonged chemotherapy, leading to refractory tumors and cancer recurrence. In this study, we demonstrated that the total steroidal saponins from Solanum nigrum L. (SN) had broad-spectrum cytotoxic activity against various human leukemia cancer cell lines, especially in adriamycin (ADR)-sensitive and resistant K562 cell lines. Moreover, SN could effectively inhibit the expression of ABC transporter in K562/ADR cells in vivo and in vitro. In vivo, by establishing K562/ADR xenograft tumor model, we demonstrated that SN might overcome drug resistance and inhibit the proliferation of tumors by regulating autophagy. In vitro, the increased LC3 puncta, the expression of LC3-II and Beclin-1, and the decreased expression of p62/SQSTM1 in SN-treated K562/ADR and K562 cells demonstrated autophagy induced by SN. Moreover, using the autophagy inhibitors or transfecting the ATG5 shRNA, we confirmed that autophagy induced by SN was a key factor in overcoming MDR thereby promoting cell death in K562/ADR cells. More importantly, SN-induced autophagy through the mTOR signaling pathway to overcome drug resistance and ultimately induced autophagy-mediated cell death in K562/ADR cells. Taken together, our findings suggest that SN has the potential to treat multidrug-resistant leukemia.

Synergistic Combination of the Total Steroidal Saponins from the Berries of Black Nightshade and Adriamycin to Overcome Leukemia Multidrug Resistance.

The berries of black nightshade (Solanum nigrum L.) are consumed as a favorite fruit in some regions and have been reported to possess a range of biological activities. Previous studies have found that the steroidal saponins from the berries of S. nigrum (SN) showed potential antileukemic activity, although the underlying mechanism remains to be revealed. This study investigated the effects and mechanisms of SN in combination with adriamycin to reverse leukemia multidrug resistance in vivo and in vitro. The results indicated that the combination of SN and adriamycin displayed enhanced suppression ability both in vitro and in vivo by the modulation of drug efflux proteins. Further study revealed that SN and adriamycin co-treatment induced cell apoptosis in K562/ADR cells through caspase pathways and autophagy through the PI3K/Akt/mTOR and MAPK signaling pathway. This study provides a new prospect of the berries of black nightshade in multidrug resistance therapy of cancer.

Screening and identification of key enzyme genes for steroidal saponin biosynthesis in Dioscorea zingiberensis under low phosphorus stress

To investigate the responses of key enzymes involved in steroidal saponin biosynthesis of Dioscorea zingiberensis to low phosphorus stress, we designed three treatments of severe phosphorus stress, moderate phosphorus stress, and normal phosphorus level. The D. zingiberensis plants were collected at the early, middle, and late stages of treatment. The content of total steroidal saponins in different tissues of D. zingiberensis was determined by spectrophotometry for the identification of the critical stage in response to low phosphorus stress. BGI 500 sequencing platform was employed to obtain the transcript information of D. zingiberensis samples at the critical stage of low phosphorus stress, and then a transcriptome library was constructed. The correlation between the expression of genes involved in steroidal saponin biosynthesis and the content of total steroidal saponins was analyzed for the screening of the key enzyme genes in response to low phosphorus stress. Further, the expression patterns of these genes were analyzed by real-time fluorescence PCR(qRT-PCR). The content of total steroidal saponins in D. zingiberensis had obvious tissue specificity under low phosphorus stress, and the early stage of stress was particularly important for D. zingiberensis to respond to low phosphorus stress. A total of 101 593 unigenes were obtained by transcriptome sequencing, of which 77.35% were annotated in NT, NR, SwissProt, KOG, GO, and KEGG. A total of 256 transcripts of known key enzyme genes in the biosynthetic pathway of steroidal saponins were identified. The expression levels of 69 transcripts encoding 18 catalytic enzymes were significantly correlated with the content of total steroidal saponins. The qRT-PCR results showed that several key enzyme genes presented different expression patterns in four tissues under low phosphorus stress. The results indicated that the content of total steroidal saponins and the expression of key enzyme genes regulating steroidal saponin biosynthesis in D. zingensis changed under low phosphorus stress. This study provides the biological information for elucidating the molecular mechanism of steroidal saponin biosynthesis in D. zingensis exposed to low phosphorus stress.

An accurate, cost-effective and simple colorimetric method for the quantification of total triterpenoid and steroidal saponins from plant materials

Saponins are heterosides widely distributed in the plant kingdom. Their properties are used in many industrial sectors, such as food, cosmetics, agriculture, and pharmaceuticals, and their use is increasing due to the market trend to use natural ingredients. Although many techniques exist to quantify saponins (e.g., gravimetric, foaming, spectrophotometric or chromatographic), none of these allow simultaneous accurate, rapid and inexpensive analysis of both triterpenoid and steroidal saponins. A new colorimetric method constituted of p-anisaldehyde and sulfuric acid was developed and avoids all of the above disadvantages. Parameters used in this method allow a similar molar absorptivity for steroidal and triterpenoid saponins with high specificity in complex matrices reducing the sample preparation step and allowing quantification of saponins blends.

Conversion of Dioscorea zingiberensis saponins to prosapogenin A by enzymatic hydrolysis

Prosapogenin A is a secondary saponin in Dioscorea zingiberensis, and it showed remarkable pharmacological effects. Due to very low content and lack of well-developed biotransformation, its preparation was not efficient and clean. This study aims to establish an eco-friendly strategy for preparation of Prosapogenin A from plant material. Physical separation was employed to recycle starch and cellulose, and then D101 resin and polyamide packed-bed column was incorporated for purification of total steroidal saponins (TSS). After these pretreatments, purity of TSS was largely increased to 83.2% with recovery at 87.6%, which was subjected to enzymatic hydrolysis. Optimized reaction system was constructed in 0.20 M HAc-NaAc buffer (pH4.2) containing cellulase/TSS (3:1, w/w), and the hydrolysis was performed at 53 °C for 6 h. Consequently, TSS was almost completely hydrolyzed to Prosapogenin A, while the highest yield reached 5.62%. The newly proposed approach is promising for efficient preparation of Prosapogenin A in industrial applications.

Transcriptomic investigation of the biochemical function of 7-dehydrocholesterol reductase 1 from the traditional Chinese medicinal plant Anemarrhena asphodeloides Bunge

Anemarrhena asphodeloides Bunge (Liliaceae) is an important Traditional Chinese Medicine herb, which contains up to 6 % total steroidal saponins (timosaponins) and has multiple pharmacological properties. However, the timosaponin biosynthetic pathway has not been extensively investigated. Here we conducted de novo transcriptome sequencing and analysis of A. asphodeloides Bunge and screened for candidate genes involved in the timosaponin biosynthetic pathway. Targeted metabolite analysis showed that timosaponins primarily accumulated in rhizomes, while phytosterols (including cholesterol) were distributed throughout various organs. Most of the identified candidate genes of the timosaponin biosynthetic pathway were also highly expressed in the rhizome, consistent with the results of metabolic analysis. Based on the transcriptome results, two candidate 7-dehydrocholesterol reductase genes were cloned and heterologously expressed in the yeast Saccharomyces cerevisiae. The purified and identified products supported that Aa7DR1 possessed Δ7-reduction activity in yeast and therefore may be involved in the timosaponins biosynthetic pathway in A. asphodeloides Bunge. Phylogenetic analysis showed Aa7DR1 belongs to monocotyledonous Δ7 reductase of phytosterol biosynthesis. These data expand our understanding of timosaponin biosynthesis.

Total saponins from Tupistra chinensis baker inhibits growth of human gastric cancer cells in vitro and in vivo

Ethnopharmacological relevanceTupistra chinensis Baker (syn. Rohdea chinensis), an antitumor folk herb mainly distributed in China, its rhizome has been historically used to treat gastric cancer. Studies showed that the steroidal saponins were the main bioactive components in the rhizome of T. chinensis. Our previous studies have confirmed that the steroidal saponins have a variety of anti-tumor activities. However, the underlying anti-tumor mechanism of the total steroidal saponins of T. chinensis (TCS) remains to be revealed. Aim of the studyIn the present study, we studied the potential anti-proliferative activity and anti-tumor mechanism of TCS on gastric cancer in vitro and in vivo. MethodsIn vitro, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to detect the proliferation ability of TCS on SGC-7901 cells and AGS cells. Flow cytometry were performed to analyze cell apoptosis, cell cycle, mitochondrial membrane potential and reactive oxygen species expression level. Western blotting was performed to validate the expression of proteins in related pathways. In vivo, a xenograft model was established by injecting SGC-7901 cells into nude mice. ResultsIn vitro, TCS inhibited the proliferation of gastric cancer cells. TCS effectively induced apoptosis by PI3K/Akt/mTOR signaling pathway in SGC-7901 cells, and promoted apoptosis via p53-mediated pathway in AGS cells. TCS also exhibited inhibitory activity in blocking the migration of gastric cancer cells. In vivo, TCS significantly inhibited the growth of xenograft tumor. ConclusionThese results indicated that TCS exhibited significant anti-gastric cancer effects in vitro and in vivo.

Purification of Paclobutrazol-Free Steroidal Saponins and Flavonoids from the Fibrous Roots of Ophiopogon japonicas

In the current study, a convenient approach was developed to isolate and purify active ingredients, including total steroidal saponins and total flavonoids, while simultaneously removing the toxic component - paclobutrazol - from the fibrous root of Ophiopogon japonicas. The separation performance of eight macroporous resins (D101, AB-8, DM301, DA201, H103, HPD100, D3520, and HP20) were evaluated using static and dynamic experimentation. The results showed that the D101 resin had the optimal capacity of adsorption and desorption to total steroidal saponins and total flavonoids. The static adsorption of D101 resins to total steroidal saponins and total flavonoids conformed to the Langmuir isotherm model and pseudo-second-order kinetic model. Under optimal purification parameters, the recovery rates of total steroidal saponins and total flavonoids were 86.49% and 87.89%, respectively. The total steroidal saponins and total flavonoids's purities increased from 16.67% to 47.58%, and from 3.82% to 12.29%, respectively. Furthermore, paclobutrazol's content decreased from 16.902mg/kg to 1.106mg/kg with a removal rate of 93.45%.

Antidiabetic activity of root tubers of Asparagus gonoclados Baker in streptozotocin induced diabetic rats

Ethnopharmacological relevanceAsparagus gonoclados Baker is a traditional folk remedy used for diabetes, diuretic, galactogogue, gastric ulcer activities etc. AimThe present investigation was intended to evaluate the beneficial effect of the A.gonoclados (Lilliaceae) root tubers against diabetes mellitus. Materials and methodsDifferent solvent extracts of root tubers of A. gonoclados were used to study the antihyperglycemic activity in streptozotocin (45 mg/kg.wt) induced diabetic rats. Oral glucose tolerance test was performed in diabetic and normal rats treated with A.gonoclados. Total phenolic content (TPC), total flavanoid content (TFC) and total steroidal saponins content (TSSC) were measured in different solvent extracts. Following bioassay guided fractionation method antihyperglycemic active fraction of A. gonoclados (AGAF) was isolated from the ethanol extract (AGEE) by silica gel column chromatography. We further tested relationship between insulin stimulation effect and the influence of active fraction on K+-ATP and Ca2+ channels opening in normal and diabetic rats. The characterization of AGAF was carried out by LC-ESI-MS/MS. ResultsAmong the different solvent extracts, the ethanol extract (AGEE) at a dose of 500 mg/kg b.wt has produced maximum (67%) reduction in fasting blood glucose levels (FBG) in diabetic treated rats after 6 h of oral administration when compared to the standard drug glibenclamide (40%). AGEE also showed dose-dependent inhibitory effect on the activities of α-glucosidase (74.73%) and α-amylase (76.47%), which is comparable to the activity of standard drug acarbose (88.42%). AGEE was found to have the richest quantity of TPCs (138.4 ± 0.39 μg/mg gallic acid equivalents), TFCs (64.8 ± 0.54 μg/mg quercetin equivalents) and TSSCs (12.9 ± 0.11μg/mg sarasapogenin equivalents). We identified 8 potential antihyperglycemic compounds in AGAF by LC-ESI-MS/MS analysis. ConclusionFrom our current study we confirm that A. gonoclados root tubers have potent antihyperglycemic activity and it can be a unique drug/formulation for the management of diabetes mellitus.

Enrichment and separation of steroidal saponins from the fibrous roots of Ophiopogon japonicus using macroporous adsorption resins.

In this study, a simple and effective strategy for the enrichment of total steroidal saponins (TSS) from the fibrous roots of Ophiopogon japonicus (L. f.) Ker-Gawl. (FROJ) using macroporous adsorption resin was systematically developed. XAD-7HP resin was selected from six macroporous resins for further study because of the highest static adsorption and desorption capacities. The static adsorption of TSS on XAD-7HP resin fitted well to the Langmuir isotherm model and pseudo second-order kinetic model; the thermodynamics test showed that the adsorption process was spontaneous and exothermic. The dynamic tests on XAD-7HP resin columns demonstrated that the breakthrough volume was 16 bed volume (BV), and 6 BV of 80% ethanol was suitable for dynamic desorption. In a lab scale-up separation under optimal dynamic conditions, the content of TSS in the resin-enrichment fraction increased from 1.83% in the crude extracts to 13.86% by 7.59-fold with a recovery yield of 82.68%. Three steroidal saponins were obtained from the resin-enrichment fraction, and showed protective effects against oxidized low-density lipoprotein (ox-LDL) induced human umbilical vein endothelial cell (HUVEC) injury. Overall, these results suggested that XAD-7HP resin chromatography was an effective strategy for the large scale enrichment of TSS from FROJ, which showed the potential for functional food and pharmaceutical application.

Determination of Total Steroid Saponins in Different Species of Paris Using FTIR Combined with Chemometrics.

The saponins of Paris spp. have antimicrobial, immune-stimulating, and antitumor biological properties. In this investigation, FTIR and ultra-HPLC (UHPLC) were used for the determination of total steroid saponins in different species of Paris from Yunnan Province, China. A 52-sample calibration set and a 26-sample validation set for partial least-squares regression (PLSR) and support vector machine regression (SVMR) combined with FTIR and UHPLC were investigated. The optimal parameters C and γ were screened by a grid search with a sevenfold cross-validation. The results indicate that pretreatment with the combination of standard normal variate, second derivative, and orthogonal signal correction had the best performance. When comparing the SVMR and PLSR models, linear PLSR had better performance than nonlinear SVMR for the determination of total steroid saponins in different species of Paris. The highest total saponin content was found in P. axialis from Baoshan City (40.92 ± 9.06 mg/g). These results demonstrate that this approach would provide a fast and robust strategy for the QC of Paris in further analyses.

Antihyperglycemic Activity of Asparagus gonoclados Root Tubers in Streptozotocininduced Diabetic Rats

Diabetes mellitus is the most common metabolic disorder affecting more than 422 million people worldwide. The available pharmacological approaches for the prevention and treatment of diabetes are not adequate due to associated side effects and higher costs. For centuries, ancient cultures across the globe emphasized the critical role of natural remedies in managing the diabetes by using them. Asparagus gonoclados is a traditional folk remedy used for diabetes mellitus in India. The present investigation was taken up to evaluate the anti‐diabetic activity of the A. gonoclados (Liliaceae) root tubers. Different solvent extracts (aqueous, ethanol, ethyl acetate and hexane) were prepared from A. gonoclados root tubers and were tested for anti‐hyperglycemic activity in streptozotocin induced diabetic rats and, anti‐α‐glucosidase and anti‐α‐amylase activity in vitro. Among the different solvent extracts, oral administration of ethanol extract (AGEE) of A. gonoclados, at a dose 500 mg/kg b.w, has produced maximum (67%) reduction in fasting blood glucose levels in diabetic treated rats after 6 hrs when compared to the glibenclamide (20 mg/kg b.w.) treated group. AGEE also has revealed the dose‐dependent inhibitory effect on α‐glucosidase and α‐amylase activities that is comparable to α‐glucosidase inhibitor drug, Acarbose. Phytochemical analysis of AGEE revealed the presence of steroidal saponins, sapogenins, phenols, flavonoids, phytosterols, tannins, triterpenes, carbohydrates, alkaloids and proteins. AGEE has the richest quantity of total phenolics (138.4±0.39 μg/mg gallic acid equivalents), flavonoids (64.8±0.54 μg/mg quercetin equivalents) and steroidal saponins (12.9±0.11 μg/mg sarasapogenin eqivalents). Further characterization of ethanol extract was carried out by LC‐ESI‐MS/MS analysis and fifteen compounds were identified. Our studies are the first to report anti‐diabetic activity of A. gonoclados root tubers. We conclude that A. gonoclados has potential therapeutic importance in the management of diabetes mellitus.Support or Funding InformationThis study is funded by Indian Council of Medical Research (ICMR, India) through major research project (No.45/18/2012).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Purification of the total steroidal saponins from fenugreek seeds (Trigonella foenum-graecum L.) using aqueous two-phase system and determination of diosgenin content using micellar electrokinetic chromatography method

The total steroidal saponins, particularly its major steroidal sapogenin (diosgenin), are the main active principles of fenugreek seed extract. In this study, an ethanol-salt aqueous two-phase system (ATPS) was explored for the purification of the total steroidal saponins, and the process conditions were optimized by response surface methodology (RSM). Under the optimized conditions, the RSM predicted recovery of the total steroidal saponins in the top phase of ATPS was 97.9%, which agreed with the average experimental recovery (98.3 ± 4.2% (n = 6)). Moreover, a rapid micellar electrokinetic chromatography (MEKC) method was developed for the determination of diosgenin from extracts. The diosgenin content in the ATPS top phase extract was 3-fold higher than that in crude extract, suggesting this ATPS having a great potential for purification pharmacological active ingredients from fenugreek seeds.

Paris Polyphylla-Derived Saponins Inhibit Growth of Bladder Cancer Cells by Inducing Mutant P53 Degradation While Up-Regulating CDKN1A Expression

Objectives: Paris polyphylla var. yunnanensis (PPVY), a Chinese herb, has long been used for cancer treatment, and its steroidal saponins are suggested to exert an anti-tumor activity, however, the underlying mechanism is incompletely understood and their effect on bladder cancer (BC) remains unknown. The present study is thus designed to address these issues. Material and Methods: Total steroidal saponins were extracted with ethanol from PPVY and used to treat BC cells (HT1197 and J82 carrying mutant p53). Gene expression was determined using qPCR and immunoblotting and cell cycle analyzed using flow cytometry. DNA damage response activation was assessed using immunofluorescence staining. Results: PPVY saponins treatment led to dose-dependent declines in the number of both HT1197 and J82 cells with IC50 approximately 1.2 μg/ml, which was coupled with strong growth arrest at G2/M phase and the activation of DNA damage response pathway. Moreover, the clonogenic potential of these cells was severely impaired even in the presence of low concentrations of PPVY saponins. Mechanistically, PPVY saponins induced the degradation of mutant p53 while stimulated CDKN1A gene transcription. Phosphorylated AKT was diminished in PPVY saponin-treated cells, but its specific inhibitor LY294002 exhibited significantly weaker efficacy in inducing CDKN1A expression than did PPVY saponins. Conclusion: PPVY saponins activate DNA damage response pathway, degrade mutant p53 and stimulate CDKN1A expression, thereby inhibiting BC cell growth. Given their poor absorption via oral administration, PPVY saponins may be applicable for intravesical instillations in BC treatment.

Safety investigation on total steroid saponins extracts from Dioscorea zingiberensis C.H. Wright: Sub-acute and chronic toxicity studies on dogs

Sub-acute and chronic toxic effects of total steroidal saponins (TSSN) extracts from Dioscorea zingiberensis C.H. Wright on various internal organs and biochemical indicators have never been studied before and this study is the first of its kind to demonstrate sub-acute and chronic toxicities of TSSN on dogs. Administration of TSSN extracts at doses up to 3000 mg/Kg daily for 14 days, no biochemical and organ changes were observed on the experimental groups of dogs. Further, chronic toxicity study through oral administration of TSSN extracts at the gradual doses of 50, 250 and 500 mg/Kg for 90 days followed by a 2-week recovery assay revealed absence of significant architectural and morphological changes in internal organs which were confirmed through histopathological examination and merely no significant alteration in the biochemical indicators including hematologic and urine analysis and electrocardiogram compared to the control dogs. This toxicological evaluation came across with the finding that the herbal preparation can be considered as nontoxic and animals could tolerate the extracts at doses up to 500 mg/Kg with LD50 greater than 3000 mg/Kg. It may serve as a preliminary scientific evidence for further therapeutic investigations.

Enrichment of total steroidal saponins from the extracts of Trillium tschonoskii Maxim by macroporous resin and the simultaneous determination of eight steroidal saponins in the final product by HPLC.

An effective and simple method was established for the separation and enrichment of steroidal saponins from Trillium tschonoskii Maxim. The adsorption and desorption properties of seven macroporous resins were investigated. Among the tested resins, AB-8 resin showed the best adsorption and desorption capacities. The adsorption of steroidal saponins on AB-8 at 25°C was quite consistent with both the Freundlich isotherm model and the pseudo-second-order kinetics model. By optimizing the dynamic adsorption and desorption parameters, the content of steroidal saponins increased from 5.20% in the crude extracts to 51.93% in the final product, with a recovery yield of 86.67%. Furthermore, by scale-up separation, the concentration and recovery of total steroidal saponins were 43.8 and 85.5%, respectively, which suggested that AB-8 resin had great industrial and pharmaceutical potential because of its high efficiency and cost-effectiveness. In addition, a high-performance liquid chromatography method for the simultaneous determination of eight steroidal saponins was established for the first time, which was employed to qualitatively and quantitatively analyze the final product. Based on the methodological validation results, the high-performance liquid chromatography method can be widely applied to the quality control of steroidal saponins from Trillium tschonoskii Maxim due to its excellent accuracy, stability, and repeatability.

A Rapid Study of Botanical Drug–Drug Interaction with Protein by Re-ligand Fishing using Human Serum Albumin–Functionalized Magnetic Nanoparticles

A great many active constituents of botanical drugs bind to human serum albumin (HSA) reversibly with a dynamic balance between the free- and bound-forms in blood. The curative or side effect of a drug depends on its free-form level, which is always influenced by other drugs, combined dosed or multi-constituents of botanical drugs. This paper presented a rapid and convenient methodology to investigate the drug-drug interactions with HSA. The interaction of two steroidal saponins, dioscin and pseudo-protodioscin, from a botanical drug was studied for their equilibrium time and equilibrium amount by re-ligand fishing using HSA functionalized magnetic nanoparticles. A clear competitive situation was obtained by this method. The equilibrium was reached soon about 15 s at a ratio of 0.44: 1. Furthermore, the interaction of pseudo-protodioscin to total steroidal saponins from DAXXK was also studied. The operation procedures of this method were faster and more convenient compared with other methods reported.

Microwave-assisted extraction and a new determination method for total steroid saponins from Dioscorea zingiberensis C.H. Wright

An efficient microwave-assisted extraction (MAE) technique was applied to isolate total steroid saponins from Dioscorea zingiberensis C.H. Wright (DZW). The optimal extracting conditions were established as 75% ethanol as solvent, ratio of solid/liquid 1:20 (g/ml), temperature 75°C, irradiation power 600W and three extraction cycles of 6min each. Scanning electron microscopy (SEM) images of DZW processed by four different extractions provided visual evidence of the disruption effect on DZW. Diosgenin was quantified by HPLC and examined further by LC–ESI/MS after acid hydrolysis. Total steroid saponins were calculated using diosgenin from total steroid saponins. The MAE procedure was optimized, validated and compared with other conventional extraction processes. This report provides a convenient technology for the extraction and quantification of total saponins of DZW combining MAE with HPLC and LC–ESI/MS for the first time.