Surface molecularly imprinted polymers based on magnetic multi-walled carbon nanotubes for the highly selective purification of resveratrol from crude extracts of Vitis vinifera, Arachis hypogaea, and Polygonum cuspidatum.

In this work, surface molecularly imprinted polymers based on magnetic multi-walled carbon nanotubes were prepared for the specific recognition and adsorption of resveratrol. The functionalization of magnetic multi-walled carbon nanotubes and the synthesis process of surface molecularly imprinted polymers were optimized. Characterizations were performed to demonstrate the successful synthesis of the imprinted materials. The imprinted materials showed satisfactory adsorption capacity of resveratrol (45.73 ± 1.72 mg/g) and excellent selectivity (imprinting factor 2.89 ± 0.15). In addition, the imprinted materials were used as adsorbents in molecularly imprinted solid-phase extraction for the purification of resveratrol from crude extracts of some food and medicinal resources, achieving recoveries of 93.69%-95.53% with high purities of 88.37%-92.33%. Moreover, the purified products exhibited extremely strong free radical scavenging activity compared with crude extracts. Overall, this work provided a promising approach for the highly selective purification of resveratrol from natural resources, which would contribute to the application of this valuable compound in the food/nutraceutical fields.

Cocultivation of pigeon pea hairy root cultures and Aspergillus for the enhanced production of cajaninstilbene acid.

Pigeon pea hairy root cultures (PPHRCs) have been proven to be a promising alternative for the production of health-beneficial phenolic compounds, such as the most important health-promoting compound, i.e., cajaninstilbene acid (CSA). In this study, PPHRCs were cocultured with live Aspergillus fungi for further improving phenolic productivity via biological elicitation. Aspergillus oryzae CGMCC 3.951 (AO 3.951) was found to be the optimal fungus that could achieve the maximum increment of CSA (10.73-fold increase) in 42-day-old PPHRCs under the inoculum size of mycelia 0.50% and cocultivation time 36 h. More precisely, the contents of CSA in hairy roots and culture media after fungal elicitation increased by 9.87- and 62.18-fold over control, respectively. Meanwhile, the contents of flavonoid glycosides decreased, while aglycone yields increased upon AO 3.951 elicitation. Moreover, AO 3.951 could trigger the oxidative stress and pathogen defense response thus activating the expression of biosynthesis- and ABC transporter-related genes, which contributed to the intracellular accumulation and extracellular secretion of phenolic compounds (especially CSA) in PPHRCs. And PAL2, 4CL2, STS1, and I3'H were likely to be the potential key enzyme genes regulating the biosynthesis of CSA, and ABCB11X1-1, ABCB11, and ABCG24X2 were closely related to the transmembrane transport of CSA. Overall, the cocultivation approach could make PPHRCs more commercially attractive for the production of high-value phenolic compounds such as CSA and flavonoid aglycones in nutraceutical/medicinal fields. And the elucidation of crucial biosynthesis and transport genes was important for systematic metabolic engineering aimed at increasing CSA productivity. KEY POINTS: • Cocultivation of PPHRCs and live fungi was to enhance CSA production and secretion. • PPHRCs augmented CSA productivity 10.73-fold when cocultured with AO 3.951 mycelia. • Several biosynthesis and transport genes related to CSA production were clarified.

An integrated approach of homogenization-ultrasound-assisted extraction followed by high-speed countercurrent chromatography for rapidly preparative separation naphthoquinones and diarylheptanes from Juglands mandshurica Maxim. exocarp.

This research investigated the effectiveness of an integrated method for the extraction and separation of naphthoquinones and diarylheptanes from exocarp of Juglands mandshurica Maxim. (namely, green walnut husks). The target compounds were obtained by ultra-turrax homogenization (UTH) coupled with ultrasound-assisted extraction (UAE) technology followed by high-speed countercurrent chromatography (HSCCC). The UTH-UAE extraction method achieved higher efficiency with 2.49- and 2.36-fold to those by UAE, and 1.39- and 1.34-fold to those by UTH in a short time. HSCCC was adopted for further separation and purification; six target compounds, namely, regiolone (RE), juglone (JU), myricatomento-genin (MG), galleon (GA), 2-oxatrycyclo[13.2.2.13,7]eicosa-3,5,7(20),15,17,18-hexaen-10-16-diol (OE), and juglanin A (JA), were separated with more than 95.37% purities and more than 84.71% final recovery rates, respectively. In this study, the integrated strategy of extraction and separation could get high purity compounds quickly, which would provide time and solvent saved method for the natural products separation from plants.

A simple and efficient sample preparation for taxanes in Taxus chinensis needles with natural menthol-based aqueous deep eutectic solvent.

Taxanes are natural anticancer constituents, and the sample preparation from matrix normally depends on organochlorine solvents. In this study, green and natural menthol-based aqueous deep eutectic solvent was synthesized and used for sample preparation for taxanes. Five key parameters were optimized and the optimal preparation conditions were as follows: menthol/1-propanol ratio 1:1 (mol/mol), solid-liquid ratio 1:30 g/mL, extraction time 30 min, ultrasonic power 250 W, and water content 80%. Under the above conditions, the total extraction efficiency of seven main taxanes was 1.25- to 1.44-fold to the conventional methods. In addition, a high-performance liquid chromatography method with C18 column was established for quantitation of seven main taxanes in <25 min, which had excellent linearity (R2  > 0.9986), precision (relative standard deviation < 3.00%), repeatability (relative standard deviation < 3.69%), and recovery (90.26-109.00%). This method performed the extraction, and enrichment processes simultaneously, and it had advantages such as high extraction efficiency, simple operation, low cost, and eco-friendliness. This work indicated that the natural menthol-based deep eutectic solvent aqueous could be an excellent alternative to the sample preparation from Taxus or other plants.

Anti-Inflammatory Effects of Neochlorogenic Acid Extract from Mulberry Leaf (Morus alba L.) Against LPS-Stimulated Inflammatory Response through Mediating the AMPK/Nrf2 Signaling Pathway in A549 Cells.

Neochlorogenic acid (nCGA) is a phenolic compound isolated from mulberry leaf (Morus alba L.), which possesses multiple pharmacological activities containing antioxidant and anti-inflammatory effects. However, the role of nCGA in the treatment of acute pneumonia and the underlying molecular mechanism are still unclear. Hence, the aim of study is to investigate the anti-inflammatory properties of nCGA on LPS-stimulated inflammation in A549 cells. In the present study, results reported that nCGA without cytotoxicity significantly reduced the production of TNF-α, IL-6, and NO, and further suppressed the proteins of iNOS, COX2, TNF-α, IL-6 expression. Furthermore, nCGA also inhibited NF-κB activation and blocked MAPKs signaling pathway phosphorylation. In addition, we found nCGA significantly increased the expression of HO-1 via activating the AMPK/Nrf2 signaling pathway to attenuate the inflammatory response, whereas this protective effect of nCGA was reversed by pre-treatment with compound C (C.C, an AMPK inhibitor). Therefore, all these results indicated that nCGA might act as a natural anti-inflammatory agent for the treatment of acute pneumonia.

ROS -mediated p53 activation by juglone enhances apoptosis and autophagy in vivo and in vitro.

Juglone (JG) exhibits a broad-spectrum of cytotoxicity against some cancer cells. However, its molecular mechanisms have not been investigated well. Here, the present results showed that JG significantly inhibited tumor growth in vivo. CCK-8 assays, flow cytometric analysis, western blotting and immunohistochemistry revealed that JG effectively inhibited cell proliferation and induced apoptosis through extrinsic pathways. We also observed that JG treatment induced autophagy flux via activiting the AMPK-mTOR signaling pathway. In addition, we found that JG enhanced p53 activation by increasing down-regulation of ubiquitin-mediated degradation. Inhibition of p53 by siRNA attenuated JG-induced cell death and autophagy. Moreover, JG enhanced the generation of hydrogen peroxide (H2O2) and superoxide anion radical (O2• -). Further experiments proved that H2O2 was a major factor since the H2O2 scavenger catalase (CAT) reduced both autophagy and cell death to a greater extent than the O2• - scavenger SOD. Overall, our results illustrated that JG caused apoptosis and autophagy via activating the ROS-mediated p53 pathway in human liver cancer cells in vitro and in vivo, which provided basic scientific evidence that JG serves as a potential anti-cancer agent.

Remarkable enhancement of flavonoid production in a co-cultivation system of Isatis tinctoria L. hairy root cultures and immobilized Aspergillus niger.

The dried roots of Isatis tinctoria L. are highly traded in the pharmaceutical industry due to their notable anti-influenza efficacy. For the first time, I. tinctoria hairy root cultures (ITHRCs) were co-cultured with two immobilized live GRAS (Generally Recognized as Safe) fungi, i.e. Aspergillus niger and Aspergillus niger, for the elevated production of pharmacologically active flavonoids. Immobilized A. niger (IAN) was exhibited as the superior elicitor in the plant-fungus co-cultivation system. The highest flavonoid production (3018.31 ± 48.66 µg/g DW) were achieved in IAN-treated ITHRCs under the optimal conditions of IAN spore concentration ca.104 spores/mL, temperature 30 °C, initial pH value of media 7.0 and time 72 h, which remarkably increased 6.83-fold relative to non-treated control (441.91 ± 7.35 µg/g DW). Also, this study revealed that IAN elicitation could trigger the sequentially transient accumulation of signal molecules and intensify the oxidative stress in ITHRCs, which both contributed to the up-regulated expression of associated genes involved in flavonoid biosynthetic pathway. Moreover, IAN could be reused at least five cycles with satisfactory performance. Overall, the coupled culture of IAN and ITHRCs is a promising and effective approach for the enhanced production of flavonoids, which allows for the improved applicability of these valuable compounds in pharmaceutical fields.

Ultraviolet radiation for flavonoid augmentation in Isatis tinctoria L. hairy root cultures mediated by oxidative stress and biosynthetic gene expression.

Search of cost-effective strategies that can enhance the accumulation of phytochemicals of pharmaceutical interest in plant in vitro cultures is an essential task. For the first time, Isatis tinctoria L. hairy root cultures were exposed to ultraviolet radiation (ultraviolet-A, ultraviolet-B, and ultraviolet-C) in an attempt to promote the production of pharmacologically active flavonoids. Results showed that the maximum flavonoid accumulation (7259.12 ±â€¯198.19 µg/g DW) in I. tinctoria hairy root cultures treated by 108 kJ/m2 dose of UV-B radiation increased 16.51-fold as compared with that in control (439.68 ±â€¯8.27 µg/g DW). Additionally, antioxidant activity enhancement and cell wall reinforcement were found in the treated I. tinctoria hairy root cultures, indicating the positive-feedback responses to oxidative stress mediated by ultraviolet-B radiation. Moreover, the expression of chalcone synthase gene was tremendously up-regulated (up to 405.84-fold) in I. tinctoria hairy root cultures following ultraviolet-B radiation, which suggested chalcone synthase gene might play a crucial role in flavonoid augmentation. Overall, the present work provides a feasible approach for the enhanced production of biologically active flavonoids in I. tinctoria hairy root cultures via the simple supplementation of ultraviolet-B radiation, which is useful for the biotechnological production of these high-added value compounds to fulfil the ever-increasing demand in pharmaceutical fields.

Chitosan elicitation of Isatis tinctoria L. hairy root cultures for enhancing flavonoid productivity and gene expression and related antioxidant activity.

Elicitation for phytochemical enhancement via cost-effective elicitors can overcome the limitation of commercial application faced by plant cell and organ culture technology. Chitosan is a natural, low-cost, and nontoxic elicitor that can trigger plant defense responses with the concomitant enhancement in phytochemical biosynthesis. In this work, the elicitation of Isatis tinctoria L. hairy root cultures by chitosan was conducted to enhance the production of pharmacologically active flavonoids. In comparison with control (2.31 ±â€¯0.29 mg/g DW), a 7.08-fold enhancement of total flavonoids (16.35 ±â€¯0.88 mg/g DW) was achieved in 24 day-old I. tinctoria hairy root cultures elicited by 150 mg/L chitosan for 36 h. Interestingly, the multiple hydroxyl-substituted flavonoids (rutin, quercetin, isorhamnetin, and isoliquiritigenin) were noticed to increase significantly in chitosan-elicited I. tinctoria hairy root cultures. Moreover, the transcription of associated genes involved in flavonoid biosynthesis pathway was significantly up-regulated underlying chitosan elicitation, among which chalcone synthase and flavonoid 3'-hydroxylase might play an important role in flavonoid enhancement. Additionally, extracts from chitosan-elicited I. tinctoria hairy root cultures exhibited higher antioxidant activities with lower IC50 values as compared with control. Overall, a cost-effective strategy via the simple chitosan elicitation is provided here to enhance the production of high-added value flavonoids in I. tinctoria hairy root cultures, which paves the way toward the successful commercialization of this in vitro culture system in the future.

Deacetylation biocatalysis and elicitation by immobilized Penicillium canescens in Astragalus membranaceus hairy root cultures: towards the enhanced and sustainable production of astragaloside IV.

A novel biotechnology approach by combining deacetylation biocatalysis with elicitation of immobilized Penicillium canescens (IPC) in Astragalus membranaceus hairy root cultures (AMHRCs) was proposed for the elevated production of astragaloside IV (AG IV). The highest AG IV accumulation was achieved in 36-day-old AMHRCs co-cultured with IPC for 60 h, which resulted in the enhanced production of AG IV by 14.59-fold in comparison with that in control (0.193 ± 0.007 mg/g DW). Meanwhile, AG IV precursors were almost transformed to AG IV by IPC deacetylation. Moreover, expression of genes involved in AG IV biosynthetic pathway was significantly up-regulated in response to IPC elicitation. Also, FTIR and SEM showed that cell wall lignification was enhanced following IPC treatment and root surface was likely to be IPC deacetylation site. Overall, dual roles of IPC (biocatalyst and elicitor) offered an effective and sustainable way for the mass production of AG IV in AMHRCs.

Production of Laccase by a New Myrothecium verrucaria MD-R-16 Isolated from Pigeon Pea [Cajanus cajan (L.) Millsp.] and its Application on Dye Decolorization.

The present study was conducted to screen a laccase-producing fungal endophyte, optimize fermentation conditions, and evaluate the decolorization ability of the laccase. A new fungal endophyte capable of laccase-producing was firstly isolated from pigeon pea and identified as Myrothecium verrucaria based on a ITS-rRNA sequences analysis. Meanwhile, various fermentation parameters on the laccase production were optimized via response surface methodology (RSM). The optimal fermentation conditions were a fermentation time of five days, temperature 30 °C and pH 6.22. Laccase activity reached 16.52 ± 0.18 U/mL under the above conditions. Furthermore, the laccase showed effective decolorization capability toward synthetic dyes (Congo red, Methyl orange, Methyl red, and Crystal violet) in the presence of the redox mediator ABTS, with more than 70% of dyes decolorizing after 24 h of incubation. Additionally, the activity of laccase was relatively stable with pH (4.5-6.5) and a temperature range of 35-55 °C. Therefore, the high laccase production of the strain and the new fungal laccase could provide a promising alterative approach for industrial and environmental applications.

Geraniin exerts cytoprotective effect against cellular oxidative stress by upregulation of Nrf2-mediated antioxidant enzyme expression via PI3K/AKT and ERK1/2 pathway.

BACKGROUND: Geraniin, an active compound with remarkable antioxidant activity, was isolated from Geranium sibiricum. The present study aimed to investigate whether geraniin has the ability to activate Nrf2, induce antioxidant enzyme expression and protect cells from oxidative damage. METHODS: The cells were pretreated with geraniin for 24h and exposed to hydrogen peroxide (H2O2) for 4h. Intracellular reactive oxygen species (ROS) levels, mitochondrial membrane potential and apoptosis were measured. We also investigated intracellular glutathione (GSH) levels and changes in nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated signaling cascade in cells treated with geraniin. RESULTS: We investigated the protective effects of geraniin against H2O2-induced apoptosis in HepG2 cells. Geraniin significantly reduced H2O2-induced oxidative damage in a dose dependent manner. Further, geraniin induced the expression of heme oxygenase-1 (HO-1), NAD(P)H quinone oxidoreductase-1 (NQO1) and level of glutathione (GSH) in a concentration- and time-dependent manner, and increased Nrf2 nuclear translocation. The Nrf2-related cytoprotective effects of geraniin were PI3K/AKT and extracellular signal-regulated protein kinase1/2 (ERK1/2) pathway-dependent. However, inhibitors of PI3K/AKT and ERK1/2 (LY294002 or U0126) not only suppressed geraniin-induced nuclear translocation of Nrf2 but also abolished the expression of HO-1, NQO1 and GSH. CONCLUSIONS: These results demonstrated that geraniin induced Nrf2-mediated expression of antioxidant enzymes HO-1 and NQO1, presumably via PI3K/AKT and ERK1/2 signaling pathways, thereby protecting cells from H2O2-induced oxidative cell death. GENERAL SIGNIFICANCE: Geraniin, at least in part, offers an antioxidant defense capacity to protect cells from the oxidative stress-related diseases.

Geraniin induces apoptosis of human breast cancer cells MCF-7 via ROS-mediated stimulation of p38 MAPK.

Geraniin, a typical ellagitannin isolated from Phyllanthus urinaria Linn, has been found to possess a range of bioactive properties. In the present study, we found that Geraniin showed potent anti-proliferative effects on human breast cancer MCF-7 cells. The IC50 values were 9.94, 17.98 and 42.32 µM after 72-, 48- and 24-h treatment, respectively. Meanwhile, Geraniin could remarkably disrupt mitochondrial membrane potential and arrest S phase cell cycle. Western-blot analysis showed that Geraniin induced phosphorylation of the anti-apoptotic Bcl-2, and the cleavage of poly (ADP-ribose) polymerase (PARP) and caspase-3 in MCF-7 cells. Moreover, Geraniin treatment activated p38 mitogen-activated protein kinase (p38 MAPK) and the effect was blunted in MCF-7 cells with the treatment of a specific p38 inhibitor SB203580. Geraniin could generate intracellular reactive oxygen species (ROS), activate p38 MAPK then induce the apoptosis in MCF-7 cells, such phenomena was abrogated by pretreatment with N-acetyl-l-cysteine. In general, these results support the conclusion that Geraniin-induced apoptosis is mediated via ROS-mediated stimulation of p38 MAPK signaling.

High-speed homogenization coupled with microwave-assisted extraction followed by liquid chromatography-tandem mass spectrometry for the direct determination of alkaloids and flavonoids in fresh Isatis tinctoria L. hairy root cultures.

A new, simple and efficient analysis method for fresh plant in vitro cultures-namely, high-speed homogenization coupled with microwave-assisted extraction (HSH-MAE) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS)-was developed for simultaneous determination of six alkaloids and eight flavonoids in Isatis tinctoria hairy root cultures (ITHRCs). Compared with traditional methods, the proposed HSH-MAE offers the advantages of easy manipulation, higher efficiency, energy saving, and reduced waste. Cytohistological studies were conducted to clarify the mechanism of HSH-MAE at cellular/tissue levels. Moreover, the established LC-MS/MS method showed excellent linearity, precision, repeatability, and reproducibility. The HSH-MAE-LC-MS/MS method was also successfully applied for screening high-productivity ITHRCs. Overall, this study opened up a new avenue for the direct determination of secondary metabolic profiles from fresh plant in vitro cultures, which is valuable for improving quality control of plant cell/organ cultures and sheds light on the metabolomic analysis of biological samples. Graphical Abstract HSH-MAE-LC-MS/MS opened up a new avenue for the direct determination of alkaloids and flavonoids in fresh Isatis tinctoria hairy root cultures.

Effective bioconversion of sophoricoside to genistein from Fructus sophorae using immobilized Aspergillus niger and Yeast.

In this study, sophoricoside from Fructus sophorae was highly bioconversed to genistein by co-immobilized Aspergillus niger and Yeast. Bioconversion conditions for genistein were optimized with single-factor experiments. The optimal conditions were as follows: microbial concentration 1.5 × 10(7) cells/mL, wet weight of microorganisms beads 10.0 g/g material, pH 5, ratio of liquid to solid 25:1 (mL/g), temperature 32 °C and time 24 h. Under these conditions, a 34.45-fold increase in production of genistein was observed with a bioreactor. Moreover, the antioxidant activities of the extracts from the fermented and untreated F. sophorae were 0.287 ± 0.11, 0.384 ± 0.08 mg/mL (IC50) and 1.84 ± 0.13, 1.28 ± 0.25 mmol Fe(II)/g, according to the DPPH test and FRAP assay, respectively. The results indicated that the method described in the current work were valuable procedure for the production of genistein, which is of most importance for industrial scale applications as well as food industry.

Dual cytoplasmic-peroxisomal compartmentalization engineering and multiple metabolic engineering strategies for high yield non-psychoactive cannabinoid in Saccharomyces cerevisiae.

CBG (Cannabigerol), a nonpsychoactive cannabinoid, has garnered attention due to its extensive antimicrobial and anti-inflammatory properties. However, the natural content of CBG in Cannabis sativa L. is minimal. In this study, we developed an engineered cell factory for CBG production using Saccharomyces cerevisiae. We introduced the CBGA biosynthetic pathway into S. cerevisiae and employed several strategies to enhance CBGA production. These strategies included dynamically inhibiting the competitive bypass of key metabolic pathways regulated by Erg20p. Additionally, we implemented a dual cytoplasmic-peroxisomal compartmentalization approach to further increase CBGA production. Furthermore, we ensured efficient CBGA production by optimizing NADPH and acetyl-CoA pools. Ultimately, our engineered strain achieved a CBG titer of 138 mg L-1 through fed-batch fermentation in a 5 L bioreactor, facilitated by microwave decarboxylation extraction. These findings underscore the significant potential of yeast cell factories for achieving higher yields in cannabinoid production.

Untargeted metabolomics reveals the regulatory effect of geniposidic acid on lipid accumulation in HepG2 cells and Caenorhabditis elegans and validation in hyperlipidemic hamsters.

BACKGROUND: Geniposidic acid (GPA) alleviates oxidative stress and inflammation in mice However, whether it can effectively regulate lipid accumulation and prevent hyperlipidemia requires further investigation. PURPOSE: This study combined the untargeted metabolomics of cells and a Caenorhabditis elegans model to evaluate the anti-hyperlipidemic potential of GPA by modulating oxidative stress and regulating lipid metabolism. A golden hamster model of hyperlipidemia was used to further validate the lipid-lowering effect and mechanism of action of GPA. METHODS: Chemical staining, immunofluorescence, and flow cytometry were performed to examine the effects of GPA on lipid accumulation and oxidative stress. Untargeted metabolomic analysis of cells and C. elegans was performed using ultra-performance liquid chromatography coupled with quadrupole electrostatic field Orbitrap high-resolution mass spectrometry (UPLC-Q-Orbitrap MS) to identify biomarkers altered by GPA action, analyze the affected metabolic pathways, and validate the mechanisms by which GPA regulates lipid metabolism and oxidative stress. A golden hamster model of hyperlipidemia was established to test the lipid-lowering effects of GPA. Body weight, biochemical markers, rate-limiting enzymes, and key proteins were assessed. Hematoxylin and eosin (H&E) and Oil Red O staining were performed. RESULTS: Phenotypic data showed that GPA decreased free fatty acid (FFA)-induced lipid buildup and high reactive oxygen species (ROS) levels, reversed the decrease in mitochondrial membrane potential (MMP), and increased the cellular reduced glutathione/oxidized glutathione disulfide (GSH/GSSG) ratio. GPA also reduces high glucose-induced lipid build-up and ROS production in C. elegans. Metabolomic analysis showed that GPA affected purine, lipid, and amino acid metabolism. Moreover, GPA inhibited xanthine oxidase (XOD), glutamate dehydrogenase (GLDH), fatty acid synthase (FAS), phosphorylation of P38 MAPK, and upregulated the expression of SIRT3 and CPT1A protein production to control lipid metabolism and produce antioxidant benefits in cells and golden hamsters. CONCLUSION: Current evidence suggests that GPA can effectively regulate lipid metabolism and the oxidative stress response, and has the potential to prevent hyperlipidemia. This study also provided an effective method for evaluating the mechanism of action of GPA.

Phlorizin from Lithocarpus litseifolius [Hance] Chun ameliorates FFA-induced insulin resistance by regulating AMPK/PI3K/AKT signaling pathway.

BACKGROUND: Insulin resistance (IR) is the central pathophysiological feature in the pathogenesis of metabolic syndrome, obesity, type 2 diabetes mellitus (T2DM), hypertension, and dyslipidemia. As the main active ingredient in Lithocarpus litseifolius [Hance] Chun, previous studies have shown that phlorizin (PHZ) can reduce insulin resistance in the liver. However, the effect of phlorizin on attenuating hepatic insulin resistance has not been fully investigated, and whether this effect is related to AMPK remains unclear. PURPOSE: The present study aimed to further investigate the effect of phlorizin on attenuating insulin resistance and the potential action mechanism. METHODS: Free fatty acids (FFA) were used to induce insulin resistance in HepG2 cells. The effects of phlorizin and FFA on cell viability were detected by MTT analysis. Glucose consumption, glycogen synthesis, intracellular malondialdehyde (MDA), superoxide dismutase (SOD), total cholesterol (TC), and triglyceride (TG) contents were quantified after phlorizin treatment. Glucose uptake and reactive oxygen species (ROS) levels in HepG2 cells were assayed by flow cytometry. Potential targets and signaling pathways for attenuating insulin resistance by phlorizin were predicted by network pharmacological analysis. Moreover, the expression levels of proteins related to the AMPK/PI3K/AKT signaling pathway were detected by western blot. RESULTS: Insulin resistance was successfully induced in HepG2 cells by co-treatment of 1 mM sodium oleate (OA) and 0.5 mM sodium palmitate (PA) for 24 h. Treatment with phlorizin promoted glucose consumption, glucose uptake, and glycogen synthesis and inhibited gluconeogenesis in IR-HepG2 cells. In addition, phlorizin inhibited oxidative stress and lipid accumulation in IR-HepG2 cells. Network pharmacological analysis showed that AKT1 was the active target of phlorizin, and the PI3K/AKT signaling pathway may be the potential action mechanism of phlorizin. Furthermore, western blot results showed that phlorizin ameliorated FFA-induced insulin resistance by activating the AMPK/PI3K/AKT signaling pathway. CONCLUSION: Phlorizin inhibited oxidative stress and lipid accumulation in IR-HepG2 cells and ameliorated hepatic insulin resistance by activating the AMPK/PI3K/AKT signaling pathway. Our study proved that phlorizin played a role in alleviating hepatic insulin resistance by activating AMPK, which provided experimental evidence for the use of phlorizin as a potential drug to improve insulin resistance.

In sight the behavior of natural Bletilla striata polysaccharide hydrocolloids by molecular dynamics method.

Plant polysaccharides, distinguished by diverse glycosidic bonds and various cyclic sugar units, constitute a subclass of primary metabolites ubiquitously found in nature. Contrary to common understanding, plant polysaccharides typically form hydrocolloids upon dissolution in water, even though both excessively high and low temperatures impede this process. Bletilla striata polysaccharides (BSP), chosen for this kinetic study due to their regular repeating units, help elucidate the relationship between polysaccharide gelation and temperature. It is suggested that elevated temperatures enhance the mobility of BSP molecular chains, resulting in a notable acceleration of hydrogen bond breakage between BSP and water molecules and consequently, compromising the conformational stability of BSPs to some extent. This study unveils the unique relationship between polysaccharide dissolution processes and temperature from a kinetics perspective. Consequently, the conclusion provides a dynamical basis for comprehending the extraction and preparation of natural plant polysaccharide hydrocolloids, pharmaceuticals and related fields.

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.