Microwave-assisted extraction of scutellarin from Erigeron breviscapus Hand-Mazz and its determination by high-performance liquid chromatography

Attapulgite amendment favors the utilization of high cadmium-contaminated soil for Erigeron breviscapus cultivation

A practical measure of soil pollution can effectively control the utilization of contaminated soil during the remediation process. In this study, Erigeron breviscapus was used as the experimental material. Soil polluted with high concentrations of cadmium (Cd) was used to study the effects of different doses of attapulgite (AP) (0, 10, 20, and 40 kg^-1 for AP0, AP10, AP20, and AP40, respectively) on the yield and quality of E. breviscapus (as measured by scutellarin), as well as soil remediation. The results showed that the yield and scutellarin content of E. breviscapus decreased by 33.4% and 78.9%, respectively, in soil contaminated with high concentrations of Cd (AP0) compared with the control soil (without Cd added). Moreover, the yield increased by 48.0% and 10.6% in AP20 and AP40, respectively, compared with AP0, and the scutellarin content increased by a factor of 2.35-2.41 in AP10, AP20, and AP40. Compared with AP0, the soil Cd content decreased by 22.5-26.2% in AP10, AP20, and AP40 and the available Cd content and acid-extractable Cd fraction in the soil also decreased. The catalase, peroxidase, superoxide dismutase activities, chlorophyll, and Fe²⁺ content were increased in AP10, AP20, and AP40, leading to an increased yield and scutellarin content. Overall, AP20 had the best effect on the yield, quality of E. breviscapus, and soil remediation. This study provides a practical measure to consider for concurrent benefits of pollution remediation and utilization of Cd-contaminated soil.

Effects of Extraction Methods on Phenolic Content, Antioxidant and Antiplatelet Activities of Tomato Pomace Extracts

Aqueous and ethanolic extracts of tomato pomace were examined with the aim of optimizing the extraction process of compounds with cardioprotective activity. Once the results of the ORAC response variables, total polyphenols, °Brix, and antiplatelet activity of the extracts were obtained, a multivariate statistical analysis was performed using the Statgraphics Centurion XIX software. This analysis showed that the most relevant positive effects in the inhibition of platelet aggregation were 83 ± 2% when using the agonist TRAP-6, when the working conditions were the type of tomato pomace conditioning (drum-drying process at 115 °C), phase ratio (1/8), type of solvent (ethanol 20%), and type of extraction (ultrasound-assisted solid-liquid extraction). The extracts with the best results were microencapsulated and characterized by HPLC. The presence of chlorogenic acid (0.729 mg/mg of dry sample) was found, a compound that has a potential cardioprotective effect documented in various studies, in addition to rutin (2.747 mg/mg of dry sample) and quercetin (0.255 mg/mg of dry sample). These results show that the extraction efficiency of compounds with cardioprotective activity depends largely on the polarity of the solvent, thus playing an important role in the antioxidant capacity of the extracts of tomato pomace.

Green approach for the recovery of secondary metabolites from the roots of Nardostachys Jatamansi (D. Don) DC using microwave radiations: Process optimization and anti-alzheimer evaluation

Nardostachys jatamansi (D. Don) DC is a highly valued medicinal herb that has been used in traditional medicinal systems for its remedial effects. Owing to the over-exploitation and unethical trade of N. jatamansi, the accelerating global demand of herbal products from this plant cannot be satisfied by the conventional extraction approach. In view of the progressive demand and incredible biological potential of herb, the present research was designed to optimize various extraction parameters for microwave-assisted extraction (MAE). The extracts obtained from the traditional and green approach were also assessed for the recovery of secondary metabolites and anti-Alzheimer's potential. Various parameters like microwave power, temperature, and time of irradiation were optimized for MAE using Box Behkhen Design (BBD) The scanning electron microscopy of different plant samples was also done to observe the effect of microwave radiations. Further, the metabolite profiling of different extracts was also done by gas chromatography-mass spectrometry (GC-MS) analysis. Also the different behavioral and biochemical parameters along with acetylcholinesterase (AChE) inhibitory potential were assessed to evaluate the anti-Alzheimer's potential. Optimized parameters for MAE were found to be as microwave power 187.04 W, temperature 90°C, and irradiation time 20 min. The extract yield in MAE was significantly enhanced as compared to the conventional method. Also, the total phenolic content and total flavonoid content (TFC) were improved pointedly from 32.13 ± 0.55 to 72.83 ± 1.1 mg of GAE/g of extract and 21.7 ± 0.85 to 39.21 ± 0.7 mg of RUE/g of extract respectively. Later, the GC-MS analysis of various extracts confirmed the enhancement in the concentration of various sesquiterpenes like jatamansone, spirojatamol, valerenal, valeric acid, globulol, nootkatone and steroidal compounds such as sitosterol, ergosterol, stigmastanone, etc. in the optimized extract. A significant improvement in anti-Alzheimer's potential was also observed owing to the better concentration of secondary metabolites in the optimized microwave extract. From the current findings, it could be concluded that the MAE could be a successful and green alternative for the extraction and recovery of secondary metabolites from the selected medicinal herb.

Application of an alkali destruction technique and natural deep eutectic solvent for greener extraction from peanut shells: optimization and extraction kinetics study

Peanut shells are an agricultural by-product rich in flavonoids, but their utilization is not high at present. This research developed a method for the rational utilization of flavonoids in peanut shells, which could enhance the comprehensive utilization of peanut resources. A green and efficient natural extraction technique based on a natural deep eutectic solvent (NADES) and alkaline destruction was exploited for the extraction of the flavonoids from peanut shells. NADES synthesized with DL-menthol (Me) and DL-lactic acid (LA) was selected as the solvent. KOH was used as a destructive agent that could destroy the structure of Me/LA, which could aid not only recovering the flavonoids, but also aid Me recovery and recycling. The NADES with the molar ratio of Me to LA of 1 : 4 showed a higher extraction capacity for flavonoids and better maintenance of antioxidant activity than water and ethanol. The maximum extraction efficiency was 23.33 mg rutin equivalents per g. In addition, the mass-transfer kinetics model of flavonoids extraction was established using Fick's second law, which well fitted the experimental results and proved that the temperature had a significant effect on the extraction efficiency. These results offered some insights for the research and exploitation of an environmentally friendly method to extract bio-active flavonoids for future applications in actual industrial manufacturing.

Comparison of the effects of different pretreatments on the structure and enzymatic hydrolysis of Miscanthus

Miscanthus is regarded as a desired bioenergy crop with enormous lignocellulose residues for biofuels and other chemical products. In this study, the effect of different pretreatments (including microwave, NaOH, CaO, and microwave + NaOH/CaO) on sugar yields was investigated, leading to largely varied hexose yields at 4.0-73.4% (% cellulose) released from enzymatic hydrolysis of pretreated Miscanthus residues. Among them, the highest yield of 73.4% for hexoses was obtained from 12% NaOH (w/v) solution pretreatment, whereas 1% CaO (w/w) and microwave pretreatment resulted in a lower hexose yield than the control (without pretreatment). The sugar yield from microwave followed with 1% NaOH pretreatment was 4.3 times higher than that of microwave followed with 1% CaO. However, the enzymatic hydrolysis efficiencies of the sample were 15.2% and 58.5% under microwave pretreatment followed by 12% NaOH or 12.5% CaO, respectively, which were lower than those of the same concentration of alkali (NaOH and CaO) pretreatments. To investigate the mechanism of varied enzymatic saccharification under different pretreatments, the changes in the surface structure and porosity of the Miscanthus-pretreated lignocelluses were studied by means of Fourier transform infrared, Congo red staining, and scanning electron microscopy analysis. The results show that the different pretreatments destroy the cell wall cladding structure and reduce the bonding force between cellulose, hemicellulose, and lignin to different degrees, therefore increasing the accessibility of cellulose and enhancing cellulose digestion.

Recent Advances in Microwave Assisted Extraction of Bioactive Compounds from Complex Herbal Samples: A Review

Microwaves are utilized for extraction of Phytoconstituents from complex herbal sample as a result of incredible research. Conventional extraction strategies are tedious and need more solvents and are no more relevant for thermal sensitive plant components. This review emphasize on the working and significance of microwave extraction technology in herbal research and medical field. The extraction step must be more yielding; quick, particular, not more solvent consuming, ensuring stability of thermolabile components and these features are available with microwave extraction method. In this nonconventional technology heat is created utilizing microwave energy. The important parameters that influence extraction efficiency are solvent properties, volume, duration of exposure, microwave control, system attributes, temperature and application were discussed in this article. The microwave assisted extraction, as green technology is contrasted with other extraction technique. This review is intended to discuss this green extraction technique along with its critical parameters for extracting bioactive compounds from complex plant matrices.

Scutellarin exerts protective effects against atherosclerosis in rats by regulating the Hippo-FOXO3A and PI3K/AKT signaling pathways

Atherosclerosis (AS), a progressive disorder, is one of the tough challenges in the clinic. Scutellarin, an extract from Herba Erigerontis, is found to have oxygen-free radicals scavenging effects and antioxidant effects. In this study, we aimed to investigate the anti-AS effects of scutellarin is related to controlling the Hippo-FOXO3A and PI3K/AKT signal pathway. To establish an AS model, the rats in the scutellarin and model groups were intraperitoneally injected with vitamin D ₃ and then fed a high-fat diet for 12 weeks. In addition, in vitro angiotensin II-induced apoptosis of human aortic endothelial cells (HAECs) were used to establish models. Scutellarin significantly reduced blood lipid levels and increased antioxidase levels in both models. Additionally, scutellarin inhibited reactive oxygen species generation and apoptosis in HAECs. The impaired vascular barrier function was restored by using scutellarin in AS rats and in HAECs cells characterized by inhibiting mammalian sterile-20-like kinases 1 (Mst1) phosphorylation, Yes-associated protein (YAP) phosphorylation, forkhead box O3A (FOXO3A) phosphorylation at serine 207, nuclear translocation of FOXO3A, and upregulating protein expression of AKT and FOXO3A phosphorylation at serine 253. Scutellarin significantly reduced Bcl-2 interacting mediator of cell death (Bim), caspase-3, APO-1, CD95 (Fas), and Bax: Bcl-2-associated X (Bax) levels and activated Bcl-2: B-cell lymphoma-2 (Bcl-2). Scutellarin also significantly inhibited the expression of Mst1, YAP, FOXO3A at the messenger RNA level. When Mst1 was overexpressed or phosphoinositide 3-kinases suppressed, the effects of scutellarin were significantly blocked. In conclusion, the results of the present study suggest that scutellarin exerts protective effects against AS by inhibiting endothelial cell injury and apoptosis by regulating the Hippo-FOXO3A and PI3K/AKT signal pathways.

Pharmacological Effects of Scutellarin, An Active Component of Genus Scutellaria and Erigeron: A Systematic Review

Flavonoid compound scutellarin (Scu) is quite frequently met in the plant kingdom, particularly in the genus Scutellaria (Lamiaceae) and Erigeron (Asteraceae). The extract of the herb of Erigeron breviscapus, containing this component in high amount, has been used for many years in traditional Chinese medicine. In recent years, studies have made great progress on the usefulness of Scu for treating various diseases by testing its mechanism of action. They support the traditional use of Scu rich plant in heart and cerebral ischemia. Scu can potentially be applied in Alzheimer's disease, Helicobacter pylori infection, vascular complications of diabetes and as an inhibitor of certain carcinomas. Various methods were designed to improve its isolation from plant material, solubility, absorption and bioavailability. On the basis of recent studies, it is suggested that Scu could be a promising candidate for new natural drug and deserves particular attention in further research and development.

Dengzhanxixin injection for cerebral infarction: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

No systematic review has been published in English of Dengzhanxixin (DZXX) injection for cerebral infarction. The aim of this systematic review was to assess the effects and safety of DZXX injection for cerebral infarction.

METHODS

Eight databases were searched from their inception. Randomized controlled trials (RCTs) related to DZXX for cerebral infarction in English or Chinese without restrictions on the publication status were included. Neurological deficit, quality of life, and response rates were analyzed. Adverse events were also investigated.

RESULTS

Twenty-three randomized controlled trials (RCTs) with 2291 participants were included. Meta-analysis showed that DZXX injection plus routine western therapy was better than routine western therapy alone for reducing neurologic deficit (MD -2.86, 95% CI -3.87 to -1.86), for improving quality of life (MD 9.48, 95% CI 8.34-10.63), and for improving response rates (RR 1.20, 95% CI 1.15-1.25). No serious adverse drug events (ADE) were reported.

CONCLUSIONS

DZXX injection may have a potential therapeutic effect for cerebral infarction in reducing neurologic deficit, improving life quality and response rates. However, we could not draw any definitive conclusions due to the insufficient evidences. More high-quality trials are needed to provide more strong evidence and to assess the safety of DZXX injection.

Extraction Methods for the Isolation of Isoflavonoids from Plant Material

The purpose of this review is to describe and compare selected traditional and modern extraction methods employed in the isolation of isoflavonoids from plants. Conventional methods such as maceration, percolation, or Soxhlet extraction are still frequently used in phytochemical analysis. Despite their flexibility, traditional extraction techniques have significant drawbacks, including the need for a significant investment of time, energy, and starting material, and a requirement for large amounts of potentially toxic solvents. Moreover, these techniques are difficult to automate, produce considerable amount of waste and pose a risk of degradation of thermolabile compounds. Modern extraction methods, such as: ultrasound-assisted extraction, microwave-assisted extraction, accelerated solvent extraction, supercritical fluid extraction, and negative pressure cavitation extraction, can be regarded as remedies for the aforementioned problems. This manuscript discusses the use of the most relevant extraction techniques in the process of isolation of isoflavonoids, secondary metabolites that have been found to have a plethora of biological and pharmacological activities.

DPPH·-luminol chemiluminescence system and its application in the determination of scutellarin in pharmaceutical injections and rat plasma with flow injection analysis

In this article, a DPPH·-luminol chemiluminescence (CL) system was reported and the CL mechanism was discussed according to the CL kinetic properties after sequence injecting DPPH· into the DPPH·-luminol reaction mixture. It was observed that scutellarin could inhibit the CL response of the DPPH·-luminol system. Based on this observation, a simple and rapid flow injection CL method was developed for the determination of scutellarin using the inhibition effect in alkaline medium. The optimized chemical conditions for the CL reaction were 5 × 10^-6  mol/L DPPH· and 1.0 × 10^-4  mol/L luminol in 0.01 mol/L NaOH. Under optimized conditions, the CL intensity was inversely proportional to the concentration of scutellarin over the ranges 5-2000 and 40-3200 ng/ml in pharmaceutical injection and rat plasma, respectively. The limits of detection (S/N = 3) were 5 and 40 ng/ml in preparations and rat plasma, respectively. Furthermore, the precision, recovery and stability of the validated method were acceptable for the determination of scutellarin in both pharmaceutical injections and rat plasma. The presented method was successfully applied in the determination of scutellarin in pharmaceutical injections and real rat plasma samples.

Rapid magnetic solid-phase extraction combined with ultra-high performance liquid chromatography and quadrupole-time-of-flight mass spectrometry for analysis of thrombin binders from a crude extract and injection of Erigeron breviscapus

Thrombin, which acts as a serine protease that converts soluble fibrinogen into insoluble strands of fibrin, plays crucial roles in the blood coagulation pathway.

Microwave-Assisted Techniques (MATs); a Quick Way to Extract a Fragrance: A Review

In recent years Microwave-Assisted Techniques (MATs) have been introduced as a new process design and operation for essential oils extraction, representing a viable alternative to conventional old-type methods of distillation which are routinely used for the isolation of essential oils from herbs, flowers and spices prior to gas chromatographic analysis. The novelty of the technique lies in a microwave heating source generating a mixture of boiling solvent with the raw plant material settled above (or drenched inside). Several variations of distillation techniques are evaluated in terms of substantial energy saving, rapidity, product yield, cleanliness and product quality. Results confirm the effectiveness of MATs, which allow extraction of essential oils in shorter extraction time (up-to 9 times faster), using “greener” procedures and provide a higher quality essential oil with better sensory and antioxidant properties.

An effective negative pressure cavitation-microwave assisted extraction for determination of phenolic compounds in P. calliantha H. Andr

A novel negative pressure and microwave assisted extraction technique (NMAE) was first proposed and applied for extraction of phenolic compounds from pyrola. [C₄MIM]BF₄ aqueous solution was selected as extraction solvent. Optimal extraction conditions were microwave power 700 W, negative pressure -0.07 MPa, temperature 40 °C, liquid-solid ratio 20 : 1, ionic liquid (IL) concentration 0.5 M, extraction time 15 min. The predominance of NMAE was investigated by comparing with microwave-assisted extraction (MAE) and negative pressure cavitation extraction (NPCE) using a first-order kinetics equation. The C∞ values of the target compounds by NMAE were from 0.406 to 5.977 mg g⁻¹ higher than these by MAE and NPCE, which indicated that NMAE had higher extraction yields. The K values of NMAE were also the highest; it was testified that the target compounds could be transferred from matrix into solvent much more effectively by NMAE than by MAE and NPCE. In addition, the NMAE method was validated in terms of repeatability and reproducibility, the relative standard deviation for relative recovery was lower than 5.43 and 8.78%, respectively. Therefore, NMAE was a developed extraction technique for analytical sample preparation. The RP-HPLC-UV method was also successfully applied for the quantification of six target compounds in pyrola.

Microwave-assisted extraction in natural products isolation

Microwave-assisted extraction (MAE) or simply microwave extraction is a relatively new extraction technique that combines microwave and traditional solvent extraction. Application of microwaves for heating the solvents and plant tissues in extraction process, which increases the kinetic of extraction, is called microwave-assisted extraction. MAE has a number of advantages, e.g., shorter extraction time, less solvent, higher extraction rate and lower cost, over traditional method of extraction of compounds from various matrices, especially natural products. The use of MAE in natural products extraction started in the late 1980s, and through the technological developments, it has now become one of the popular and cost-effective extraction methods available today, and several advanced MAE instrumentations and methodologies have become available, e.g., pressurized microwave-assisted extraction (PMAE) and solvent-free microwave-assisted extraction (SFMAE). This chapter provides an overview of the MAE and presents a number of specific protocols for natural products extraction.

Optimization of microwave-assisted extraction followed by RP-HPLC for the simultaneous determination of oleanolic acid and ursolic acid in the fruits of Chaenomeles sinensis

An optimized microwave-assisted extraction (MAE) method and an efficient HPLC analysis method were developed for fast extraction and simultaneous determination of oleanolic acid and ursolic acid in the fruit of Chaenomeles sinensis. The open vessel MAE process was optimized by using a central composite experimental design. The optimal conditions identified were microwave power 600 W, temperature 52 degrees C, solvent to material ratio 32 mL/g and extraction time 7 min. The results showed that MAE is a more rapid extraction method with higher yield and lower solvent consumption. The HPLC-photodiode array detection analysis method was validated to have good linearity, precision, reproduction and accuracy. Compared with conventional extraction and analysis methods, MAE-HPLC-photodiode array detection is a faster, convenient and appropriate method for determination of oleanolic acid and ursolic acid in the fruits of C. sinensis.

Microwave-assisted extraction with water for fast extraction and simultaneous RP-HPLC determination of phenolic acids in radix Salviae Miltiorrhizae

An optimized microwave-assisted extraction method using water (MAE-W) as the extractant and an efficient HPLC analysis method were first developed for the fast extraction and simultaneous determination of D(+)-(3,4-dihydroxyphenyl) lactic acid (Dla), salvianolic acid B (SaB), and lithospermic acid (La) in radix Salviae Miltiorrhizae. The key parameters of MAE-W were optimized. It was found that the degradation of SaB was inhibited when using the optimized MAE-W and the stable content of Dla, La, and SaB in danshen was obtained. Furthermore, compared to the conventional extraction methods, the proposed MAE-W is a more rapid method with higher yield and lower solvent consumption with a reproducibility (RSD <6%). In addition, using water as extractant is safe and helpful for environment protection, which could be referred to as green extraction. The separation and quantitative determination of the three compounds was carried out by a developed reverse-phase high-performance liquid chromatographic (RP-HPLC) method with UV detection. Highly efficient separation was obtained using gradient solvent system. The optimized HPLC analysis method was validated to have specificity, linearity, precision, and accuracy. The results indicated that MAE-W followed by HPLC-UV determination is an appropriate alternative to previously proposed method for quality control of radix Salviae Miltiorrhizae.

Application of microwave-assisted extraction coupled with high-speed counter-current chromatography for separation and purification of dehydrocavidine from Corydalis saxicola Bunting

INTRODUCTION

Dehydrocavidine is a major component of Corydalis saxicola Bunting with sedative, analgesic, anticonvulsive and antibacterial activities. Conventional methods have disadvantages in extracting, separating and purifying dehydrocavidine from C. saxicola. Hence, an efficient method should be established.

OBJECTIVE

To develop a suitable preparative method in order to isolate dehydrocavidine from a complex C. saxicola extract by preparative HSCCC.

METHODOLOGY

The methanol extract of C. saxicola was prepared by optimised microwave-assisted extraction (MAE). The analytical HSCCC was used for the exploration of suitable solvent systems and the preparative HSCCC was used for larger scale separation and purification. Dehydrocavidine was analysed by high-performance liquid chromatography (HPLC) and further identified by ESI-MS and 1H NMR.

RESULTS

The optimised MAE experimental conditions were as follows: extraction temperature, 60 degrees C; ratio of liquid to solid, 20; extraction time, 15 min; and microwave power, 700 W. In less than 4 h, 42.1 mg of dehydrocavidine (98.9% purity) was obtained from 900 mg crude extract in a one-step separation, using a two-phase solvent system composed of chloroform-methanol-0.3 m hydrochloric acid (4 : 0.5 : 2, v/v/v).

CONCLUSION

Microwave-assisted extraction coupled with high-speed counter-current chromatography is a powerful tool for extraction, separation and purification of dehydrocavidine from C. saxicola.

Plant regeneration of Erigeron breviscapus (vant.) Hand. Mazz. and its chromatographic fingerprint analysis for quality control

An efficient micropropagation system for Erigeron breviscapus (vant.) Hand. Mazz., an important medicinal plant for heart disease, has been developed. Shoot organogenesis occurred from E. breviscapus leaf explants inoculated on a medium supplemented with a combination of plant growth regulators. On average, 17 shoots per leaf explant were produced after 30 days when they were cultured on MS basal salts and vitamin medium containing 5 microM 6-benzylaminopurine (BAP) and 5 microM 1-naphthaleneacetic acid (NAA). All the regenerated shoots formed complete plantlets on a medium containing 2.5-10 microM indole-3-butyric acid (IBA) within 30 days, and 80.2% of the regenerated plantlets survived and grew vigorously in field conditions. Based on the variation in common peaks and the produced amount of the most important bioactive component, scutellarin, a high performance liquid chromatography (HPLC) fingerprinting system was developed for quality control of these micropropagated plants. Chemical constituents in E. breviscapus micropropagated plants varied during plant development from regeneration to maturation, the latter of which showed the most similar phytochemical profile in comparison with mother plants. The regeneration protocol and HPLC fingerprint analysis developed here provided a new approach to quality control of micropropagated plants producing secondary metabolites with significant implications for germplasm conservation.

Separation of scutellarin from crude extracts of Erigeron breviscapus (vant.) Hand. Mazz. by macroporous resins

Scutellarin, a flavone glycoside, popularly used in the treatment of heart disease, has been efficiently separated using macroporous resins from crude extracts of Chinese medicinal plant Erigeron breviscapus (vant.) Hand. Mazz. HPD-800 resin offered the best adsorption and desorption capacity for scutellarin among the eight macroporous resins tested, and its adsorption data at 25 degrees C fit best to the Langmuir isotherm. The dynamic adsorption and desorption experiments have been carried out on a HPD-800 resin packed column to optimize the separation process of scutellarin from the crude extracts of E. breviscapus. After one run treatment with HPD-800 resin, the scutellarin content in the product was increased 15.69-fold from 2.61% to 40.96% with a recovery yield of 95.01%. The preparative separation process via adsorption-desorption method developed in this study provides a new approach for scale-up separation and purification of scutellarin for its wide pharmaceutical use.