Antioxidant and anti-inflammatory properties of flavonoids from lotus plumule

Influence of Accelerated Solvent Extraction Conditions on the LC-ESI-MS/MS Polyphenolic Profile, Triterpenoid Content, and Antioxidant and Anti-lipoxygenase Activity of Rhododendron luteum Sweet Leaves

Evaluation of native plant resources and their efficient use is one of the current trends in phytochemistry. The main aim of the present study was to investigate the biological activities of different Rhododendron luteum Sweet leaf extracts obtained with the use of accelerated solvent extraction using different solvents and extraction temperatures. All extracts were subjected to bioactivity assays, which revealed considerable anti-lipoxygenase (23.07-90.13% lipoxygenase inhibition) and antiradical potential. All samples exhibited high 2,2-diphenyl-1-picrylhydrazyl (DPPH^•) (234.18-621.90 mg Trolox equivalents (TE)/g) and 2,2'-azino-bis-3(ethylbenzthiazoline-6-sulphonic acid) (ABTS^•+) (88.79-349.41 mg TE/g) scavenging activity, high antioxidant potential in the Oxygen Radical Absorbance Capacity (ORAC) assay (495.77-1011.59 mg TE/g), and moderate ion chelating (Fe2+) capacity. The chemical profile of each sample was determined using liquid chromatography/electrospray ionization triple quadrupole mass spectrometry (LC-ESI-MS/MS) and spectrophotometric procedures. Twenty-three compounds representing seven polyphenol subclasses were detected and quantified, including some phenolic acids and flavonoids that had not been previously reported for this plant material. It was shown that 5-O-caffeoylquinic acid, protocatechuic acid, catechin, quercetin and its glycosides (hyperoside, isoquercetin, quercitrin), and pentacyclic triterpenes were the dominant secondary metabolites in R. luteum leaves. The antioxidant activity was found to be strongly related to different polyphenol groups and total triterpene content, while the anti-lipoxygenase potential was highly dependent on catechin.

Comparison of In Vitro and In Vivo Antioxidant Activities of Six Flavonoids with Similar Structures

The in vitro and in vivo antioxidant activities of six flavonoids with similar structures, including epicatechin (EC), epigallocatechin (EGC), procyanidin B2 (P), quercetin (Q), taxifolin (T), and rutin (R) were compared. The structures of the six flavonoids and their scavenging activities for 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺) radicals were closely related. The flavonoids decreased serum contents of malondialdehyde (MDA) and nitric oxide (NO), and increased serum total antioxidative capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) levels to different degrees in d-galactose-treated mice. The changes in mRNA expression of liver GSH-Px1, CAT, SOD1, and SOD2 by d-galactose were dissimilarly restored by the six flavonoids. Moreover, the six flavonoids differentially prevented the inflammatory response caused by oxidative stress by inhibiting interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α levels, and restoring IL-10 levels. These six flavonoids from two subclasses revealed the following antioxidant capability: P > EC, EGC > EC, Q > T, Q > R. Our results indicate that (1) the pyrogallol, dimerization, and C2=C3 double bonds of flavonoids enhanced antioxidant activity and (2) the C3 glycosylation of flavonoids attenuated antioxidant capacity.

Efficiency comparison of apigenin-7-O-glucoside and trolox in antioxidative stress and anti-inflammatory properties

OBJECTIVES

Chamomile has long been used as a medicinal plant due to its antioxidative and anti-inflammatory activity. Apigenin-7-O-glucoside (AG) is one of the major ethanol extract components from chamomile; however, the underlying mechanism remains unclear.

METHODS

In this study, the antioxidant potential and the anti-inflammatory activities of AG were analysed and compared with those of trolox. We demonstrate the protective effects of AG on free radical-induced oxidative damage of DNA, proteins and erythrocytes. Flow cytometry assay was used to detect ROS production. Additionally, the expression of anti-oxidation-related and inflammation-related factors was detected by ELISA and Western blotting, respectively.

KEY FINDINGS

AG and trolox showed different efficiency as antioxidant in different experimental systems. AG had similar effect as trolox to inhibit H₂ O₂ -induced ROS production in RAW264.7 cells, while exerted stronger inhibition against free radical-induced oxidative damage on erythrocytes than trolox. Interestingly, compared with trolox, AG also had stronger inhibitory effect on LPS-induced NF-κB/NLRP3/caspase-1 signalling in RAW246.7 cells.

CONCLUSIONS

These results suggest the potential of AG as a pharmaceutical drug for anti-oxidation and anti-inflammation, and the combined usage of AG and trolox might promote its efficacy. Our findings will provide new insights into the development of new drugs with antioxidative and anti-inflammatory functions.

Enhanced antioxidant, anti-inflammatory and α-glucosidase inhibitory activities of citrus hesperidin by acid-catalyzed hydrolysis

Hesperidin hydrolysates (HHS) was produced by the hydrolysis of hesperidin (HDN) in previous studies. The potential components in HHS were identified by LC-MS, and minor components (MCS) in HHS were isolated. Antioxidant activities by radical-scavenging capacities, reducing capacity and β-carotene-linoleate assay, anti-inflammatory effects by inhibiting NO production of RAW 264.7 cells, and α-glucosidase inhibitory effects of HDN, HHS, MCS and henperetin (HTN) were investigated in present study. HHS showed higher radical scavenging activities, higher reducing capacity, and higher inhibitory activity in the β-carotene-linoleate assay than HDN. HHS inhibited the production of NO and pro-inflammatory cytokines of RAW 264.7 cells more strongly than HDN. HHS also intensively inhibited α-glucosidase activity whereas HDN showed little activity. In addition, the effects of MCS on above activities showed it play a synergistic part with HTN. This work suggested that hydrolyzation of HDN enhance the activities, and provided valuable information on effective utilization of HDN.

Polyphenols and their applications: An approach in food chemistry and innovation potential

Polyphenols are compounds naturally present in fruits and vegetables that are gaining more and more attention due to their therapeutic effects and their potential technological applications. In this review, we intend to demonstrate the importance of some phenolic compounds, addressing their biological effects and potential for applications in various industrial fields. The intake of these compounds in appropriate concentrations can present promising effects in the prevention of diseases such as diabetes, obesity, Parkinson's, Alzheimer's, and others. They can also be used to improve the physicochemical properties of starch, in the preservation of foods, as natural dyes, prebiotic ingredients, hydrogels and nanocomplexes. In addition, these compounds have potential for innovation in the most diverse technological fields, including organic fine chemistry, basic materials chemistry, pharmaceuticals, food chemistry, chemical engineering, etc.

Hypoglycemic and hypolipidemic effects of Moringa oleifera leaves and their functional chemical constituents

Moringa oleifera Lam. (M. oleifera) leaves have long been consumed as both nutritive vegetable and popular folk medicine for hyperglycemia and hyperlipidemia in Kenya communities. In the current study, in vitro inhibition by M. oleifera leaf extract (MOLE, 90% (v/v) ethanol) of α-glucosidase and pancreatic lipase was demonstrated, followed by determination of the effects of MOLE on both glucose consumption and lipid levels (TC, TG, HDL-C and LDL-C) in 3T3-L1 cells. Potential ligands in MOLE were fast screened using affinity ultrafiltration LC-MS, and 14 and 10 components displayed certain binding affinity to α-glucosidase and pancreatic lipase, respectively. Docking studies revealed the binding energies and hydrogen bonds between potential ligands and enzymes. This study suggests that M. oleifera leaves may be a promising natural source for the prevention and treatment of hyperglycemia and hyperlipidemia as well as a functional food or other product for health care in the near future.

A Hybrid Peptide DEFB-TP5 Expressed in Methylotrophic Yeast Neutralizes LPS With Potent Anti-inflammatory Activities

DEFB-TP5 is a novel auspicious health-beneficial peptide derivative from two naturally occurring peptides, β-Defensin (DEFB) and thymopentin (TP5), and shows strong anti-inflammatory activity and binds to LPS without cytotoxicity and hemolytic effect. Furthermore, the application of DEFB-TP5 peptide is inadequate by its high cost. In the current study, we developed a biocompatible mechanism for expression of the DEFB-TP5 peptide in Pichia pastoris. The transgenic strain of hybrid DEFB-TP5 peptide with a molecular weight of 6.7kDa as predictable was obtained. The recombinant DEFB-TP5 peptide was purified by Ni-NTA chromatography, estimated 30.41 mg/L was obtained from the cell culture medium with 98.2% purity. Additionally, The purified DEFB-TP5 peptide significantly (p< 0.05) diminished the release of nitric oxide (NO), TNF-α, IL-6, IL-1β in LPS-stimulated RAW264.7 macrophages in a dose-dependent manner. This study will not only help to understand the molecular mechanism of expression that can potentially be used to develop an anti-endotoxin peptide but also to serve as the basis for the development of antimicrobial and anti-inflammatory agents as well, which also provides a potential source for the production of recombinant bioactive DEFB-TP5 at the industrial level.

Phenolics, flavonoids and antioxidant capacities in Citrus species with different degree of tolerance to Huanglongbing

Huanglongbing (HLB) is a highly destructive disease to the citrus industry in Florida caused by the bacterium, Candidatus Liberibacter asiaticus(CLas) and is transmitted by Diaphorina citri. It is hypothesized that plants with high phenolic contents show higher tolerance to certain plant pathogens. In this regard, different citrus varieties and plants of genera related to Citrus were analyzed for their total phenolic and flavonoids contents, and their antioxidant capacities. In addition, the secondary metabolites in the leaves of seven citrus species were analyzed using high performance liquid chromatography-mass spectrometry (HPLC-MS). Colorimetric assays showed that curry leaf contained the highest total phenolic content and free radical scavenging activity (DPPH). Curry leaf also contained high concentrations of an unusual class of carbazole alkaloids. Tolerant Citrus species contained high levels of phenolics and flavonoids and showed high antioxidant capacities. Our results suggest that high phenolic and flavonoid leaf contents correlate with increased citrus tolerance to CLas bacterium. The results also suggest that the high level of carbazole alkaloids, known for their strong antimicrobial properties in curry leaf, could make it immune to the CLas bacteria. Understanding the mechanisms underpinning citrus tolerance to HLB will contribute to the development of commercially tolerant citrus cultivars.

Conventional and Emerging Extraction Processes of Flavonoids

Flavonoids are a group of plant constituents called phenolic compounds and correspond to the nonenergy part of the human diet. Flavonoids are found in vegetables, seeds, fruits, and beverages such as wine and beer. Over 7000 flavonoids have been identified and they have been considered substances with a beneficial action on human health, particularly of multiple positive effects because of their antioxidant and free radical scavenging action. Although several studies indicate that some flavonoids have provident actions, they occur only at high doses, confirming in most investigations the existence of anti-inflammatory effects, antiviral or anti-allergic, and their protective role against cardiovascular disease, cancer, and various pathologies. Flavonoids are generally removed by chemical methods using solvents and traditional processes, which besides being expensive, involve long periods of time and affect the bioactivity of such compounds. Recently, efforts to develop biotechnological strategies to reduce or eliminate the use of toxic solvents have been reported, reducing processing time and maintaining the bioactivity of the compounds. In this paper, we review, analyze, and discuss methodologies for biotechnological recovery/extraction of flavonoids from agro-industrial residues, describing the advances and challenges in the topic.

Studies on the Anti-Gouty Arthritis and Anti-hyperuricemia Properties of Astilbin in Animal Models

The purpose of this study was to investigate potential anti-gouty effect of astilbin (AS) and its possible mechanisms. In mice with hyperuricemia induced by potassium oxonate (OXO) and yeast extract powder (YEP), AS and febuxostat (FB) reduced the serum uric acid (UA) and xanthine oxidase (XO). Moreover, AS and FB reduced the levels of reactive oxygen species and increased the content of superoxide dismutase (SOD), glutathione peroxidase and catalase present in the serum. In acute gouty arthritis rats induced by intraarticular monosodium urate crystal injection, AS and Colchicine (COL) alleviated the ankle joints swelling, and reduced the inflammatory cell infiltration. AS also reduced the levels of interleukin 1β, interleukin 6, tumor necrosis factor alpha and monocyte chemoattractant protein 1 in liver. The present study first confirmed the anti-gouty effect of AS in mice with hyperuricemia and rats with acute gouty arthritis, which provides the experimental evidence for further evaluation of AS as a candidate for gout treatment.

Synergistic anti-inflammatory activities of a new flavone and other flavonoids from Tephrosia hildebrandtii vatke

A new flavone, named hildeflavone (1) along with 7 other known flavonoids were isolated from the aerial parts of Tephrosia hildebrandtii Vatke. Their characterisation was based on NMR and MS data analysis. The anti-inflammatory properties of the crude extract, isolated compounds and combination of the compounds were investigated in lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs). Treatment of the LPS-stimulated PBMCs with the isolated flavonoids at a concentration of 100 µM significantly reduced the production of interleukins (IL-1β, IL-2 and IL-6), interferon-gamma (IFN-γ), granulocyte macrophage-colony stimulating factor (GM-CSF) and tumour necrosis factor-alpha (TNF-α). It was also found that the combination of a flavone and flavanones exhibited remarkable synergistic anti-inflammatory effects on the production of the cytokines.

Antioxidant, Anti-inflammatory Activities and Polyphenol Profile of Rhamnus prinoides

Rhamnus prinoides L’Herit (R. prinoides) has long been widely consumed as folk medicine in Kenya and other Africa countries. Previous studies indicated that polyphenols were abundant in genus Rhamnus and exhibited outstanding antioxidant and anti-inflammatory activities. However, there are very few studies on such pharmacological activities and the polyphenol profile of this plant up to now. In the present study, the antioxidant activities of the crude R. prinoides extracts (CRE) and the semi-purified R. prinoides extracts (SPRE) of polyphenol enriched fractions were evaluated to show the strong radical scavenging effects against 1,1-diphenyl-2- picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH) (0.510 ± 0.046 and 0.204 ± 0.005, mg/mL), and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) (0.596 ± 0.005 and 0.096 ± 0.004, mg/mL), respectively. Later, the SPRE with higher contents of polyphenols and flavonoids displayed obvious anti-inflammatory activities through reducing the NO production at the dosage of 11.11 − 100 μg/mL, and the COX-2 inhibitory activity with an IC₅₀ value at 20.61 ± 0.13 μg/mL. Meanwhile, the HPLC-UV/ESI-MS/MS analysis of polyphenol profile of R. prinoides revealed that flavonoids and their glycosides were the major ingredients, and potentially responsible for its strong antioxidant and anti-inflammatory activities. For the first time, the present study comprehensively demonstrated the chemical profile of R. prinoides, as well as noteworthy antioxidant and anti-inflammatory activities, which confirmed that R. prinoides is a good natural source of polyphenols and flavonoids, and provided valuable information on this medicinal plant as folk medicine and with good potential for future healthcare practice.

Pathway-specific enzymes from bamboo and crop leaves biosynthesize anti-nociceptive C-glycosylated flavones

C-glycosylated flavones (CGFs) are promising candidates as anti-nociceptive compounds. The leaves of bamboo and related crops in the grass family are a largely unexploited bioresource with a wide array of CGFs. We report here pathway-specific enzymes including C-glycosyltransferases (CGTs) and P450 hydroxylases from cereal crops and bamboo species accumulating abundant CGFs. Mining of CGTs and engineering of P450s that decorate the flavonoid skeleton allowed the production of desired CGFs (with yield of 20–40 mg/L) in an Escherichia coli cell factory. We further explored the antinociceptive activity of major CGFs in mice models and identified isoorientin as the most potent, with both neuroanalgesic and anti-inflammatory effects superior to clinical drugs such as rotundine and aspirin. Our discovery of the pain-alleviating flavonoids elicited from bamboo and crop leaves establishes this previously underutilized source, and sheds light on the pathway and pharmacological mechanisms of the compounds.

Yuwei Sun, Zhuo Chen, Jingya Yang et al. identify bamboo as a rich source of C-glycosylated flavonoids that reduces pain and inflammation. They identify isoorientin as the most potent C-glycosylated flavonoid, superior to aspirin, and report new enzymes that synthesize pain-alleviating C-glycosylated flavonoids.

UHPLC-ESI-HRMS/MS analysis on phenolic compositions of different E Se tea extracts and their antioxidant and cytoprotective activities

E Se tea, prepared from the leaves of Malus toringoides (Rehd.) Hughes, is a traditional beverage, but there is little known about its chemical substances. This paper is aimed to investigate the chemical composition, antioxidant, and cytoprotective activities of the extract and fractions from E Se tea. Sixteen compounds were characterized by UHPLC-ESI-HRMS/MS. Phloridzin was the main compound, especially in ethyl acetate fraction (EAF). Moreover, EAF had the highest total phenolic and flavonoid contents with 197.54 ± 7.52 mg gallic acid equivalents/g extract and 85.94 ± 5.39 mg rutin equivalents/g extract, respectively, and exhibited the strongest antioxidant capacity (DPPH: IC₅₀ = 54.91 ± 3.38 μg/mL; ABTS: IC₅₀ = 98.08 ± 6.92 μg/mL). Different fractions of E Se tea, especially EAF, significantly inhibited intracellular ROS generation, reduced cell apoptosis, and decreased oxidative stress damage in H₂O₂-induced HepG-2 cells. Therefore, the obtained results highlight that E Se tea is a promising source for functional beverage or nutritional foods.

Dynamics of antioxidant activities, metabolites, phenolic acids, flavonoids, and phenolic biosynthetic genes in germinating Chinese wild rice (Zizania latifolia)

In this study, the antioxidant activity of germinating Chinese wild rice was found to decline initially, after which it increased. The largest difference in antioxidant activity was observed between the 36-h (G36) and the 120-h germination (G120) stage. We further assessed the dynamic changes in metabolites, phenolic acids, flavonoids, and phenolic biosynthetic genes in germinating Chinese wild rice. Ultra-high performance liquid chromatography-triple quadrupole mass spectrometry revealed that 315 metabolites were up-regulated and 28 were down-regulated between G36 and G120. Levels of p-hydroxybenzoic acid, p-hydroxybenzaldehyde, vanillin, p-coumaric acid, ferulic acid, and epigallocatechin increased significantly during germination. Gene expression of four phenylalanine ammonia-lyases, one 4-coumarate-CoA ligase, one cinnamoyl-CoA reductase, two cinnamyl alcohol dehydrogenases, one chalcone synthase, and one chalcone isomerase was significantly higher at G120 than at G36 and promoted phenolics accumulation. This study elucidated the biochemical mechanisms involved in antioxidant activity and phenolic profile changes during Chinese wild rice germination.

Euryops arabicus displays anti-inflammatory activities in experimental models

ETHNOPHARMACOLOGICAL RELEVANCE

Euryops arabicus (Asteraceae) is grown in Arab Peninsula. Its aerial parts possess ethnomedicinal applications against several inflammatory conditions.

AIM OF THE STUDY

To evaluate the anti-inflammatory activity of Euryops arabicus (E. arabicus) organic extract as well as its major polymethoxylated flavonoids.

MATERIALS AND METHODS

Acute toxicity of the total extract of E. ararbicus was evaluated by assessing LD₅₀. In vivo anti-inflammatory activity was evaluated in rats injected with carrageenan in the plantar area. Paw edema volume, histological changes and rats'stair climbing and motility were assessed. In vitro anti-inflammatory activity of the isolated compounds was evaluated in peripheral blood mononuclear cells (PBMCs) challenged with carrageenan. Inflammation markers were assessed in cellular lysates and collected media.

RESULTS

The extract was found safe and considered unclassified with an oral LD₅₀ > 2000 mg/kg in rats. Pretreatment of rats with a total extract of E. arabicus at doses of 100 and 250 mg/kg significantly inhibited carrageenan-induced increase in paw edema volume and histopathological changes. Also, it significantly ameliorated diminution of climbing and motility. Phytochemical studies led to the isolation and identification of five polymethoxylated flavonoids. The anti-inflammatory properties of the isolated compounds were evaluated in carrageenan-challenged peripheral blood mononuclear cells (PBMCs). All compounds exhibited appreciable antioxidant activities. Further, pre-incubation of the cells with the isolated metabolites significantly ameliorated the rise in cyclo-oxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and monocyte chemoattractant protein-1 (MCP-1) induced by carrageenan challenge. Further, the compounds inhibited the leakage of interleukin-1β (IL-1β), interleukin-6 (IL-6) and myeloperoxidase (MPO) in media collected from stimulated cells.

CONCLUSION

E. arabicus exhibited in vivo anti-inflammatory effects in the carrageenan model as it ameliorated rat paw edema, histopathological changes and movement dysfunction. in vitro activity of isolated compounds was confirmed in stimulated PBMCs. Thus, the anti-inflammatory activity of E. arabicus can be attributed, at least partly, to its anti-oxidant, anti-inflammatory and anti-chemotactic properties.

Evaluation of wound healing effect of chitosan-based gel formulation containing vitexin

Acute or chronic wounds are one of the most common health problems worldwide and medicinal drugs or traditional remedies are often used in wound healing. Further studies regarding wound treatment are rapidly continuing. Vitexin is a phenolic compound, which is found in many medicinal plants, has different pharmacological effects such as anti-inflammatory, analgesic and antioxidant. In the present study, it is aimed to investigate the wound healing effect of formulation prepared as chitosan-based gel with vitexin in vivo and in vitro. Cytotoxicity and wound healing assays were used for in vitro and excisional wound model is used for in vivo studies. Extracted tissues from wound area were histologically examined. Wound healing process was monitored on 7, 14 and 21st days. When wound construction was evaluated, chitosan-based gel formulation containing vitexin demonstrated significant effect compared to control group. Histological examinations demonstrated that skin regeneration was promoted by vitexin formulation. Significant cell proliferation was observed with vitexin/chitosan dispersion in the wound healing assay performed with NIH 3T3 and HaCaT cells. In conclusion, our test substance chitosan-based gel formulation containing vitexin significantly accelerated wound healing both in vivo and in vitro.

Separation, Identification, and Antioxidant Activity of Polyphenols from Lotus Seed Epicarp

Lotus seed epicarp, the main by-product of lotus seed processing, is abundant in polyphenols. In this study, polyphenols in lotus seed epicarp were separated by Sephadex LH-20 gel filtration chromatography to yield Fraction-I (F-I), Fraction-II (F-II), and Fraction-III (F-III). The polyphenol compounds in the three fractions were identified by UPLC-MI-TOF-MS. Six kinds of polyphenol compounds including cyanidin-3-O-glucoside, procyanidin trimer, and phlorizin were identified in F-I, and prodelphinidin dimer B, procyanidin dimer, and quercetin hexoside isomer were found in F-II. However, there was only procyanidin dimer identified in F-III. The in vitro antioxidant activities of the three fractions were also investigated. We found F-I, F-II, and F-III had strong potential antioxidant activities in the order of F-III > F-II > F-I. Our results suggested that polyphenols from lotus seed epicarp might be suitable for use as a potential food additive.

Advances in MS Based Strategies for Probing Ligand-Target Interactions: Focus on Soft Ionization Mass Spectrometric Techniques

The non-covalent interactions between small drug molecules and disease-related proteins (ligand-target interactions) mediate various pharmacological processes in the treatment of different diseases. The development of the analytical methods to assess those interactions, including binding sites, binding energies, stoichiometry and association-dissociation constants, could assist in clarifying the mechanisms of action, precise treatment of targeted diseases as well as the targeted drug discovery. For the last decades, mass spectrometry (MS) has been recognized as a powerful tool to study the non-covalent interactions of the ligand-target complexes with the characteristics of high sensitivity, high-resolution, and high-throughput. Soft ionization mass spectrometry, especially the electrospray mass spectrometry (ESI-MS) and matrix assisted laser desorption ionization mass spectrometry (MALDI-MS), could achieve the complete transformation of the target analytes into the gas phase, and subsequent detection of the small drug molecules and disease-related protein complexes, and has exerted great advantages for studying the drug ligands-protein targets interactions, even in case of identifying active components as drug ligands from crude extracts of medicinal plants. Despite of other analytical techniques for this purpose, such as the NMR and X-ray crystallography, this review highlights the principles, research hotspots and recent applications of the soft ionization mass spectrometry and its hyphenated techniques, including hydrogen-deuterium exchange mass spectrometry (HDX-MS), chemical cross-linking mass spectrometry (CX-MS), and ion mobility spectrometry mass spectrometry (IMS-MS), in the study of the non-covalent interactions between small drug molecules and disease-related proteins.

The Natural Flavonoid Galangin Elicits Apoptosis, Pyroptosis, and Autophagy in Glioblastoma

Galangin (GG), a flavonoid, elicits a potent antitumor activity in diverse cancers. Here, we evaluated the efficacy of GG in the treatment of human glioblastoma multiforme (GBM) and investigated the molecular basis for its inhibitory effects in the disease. GG inhibited viability and proliferation of GBM cells (U251, U87MG, and A172) in a dose-dependent manner (IC₅₀ = 221.8, 262.5, 273.9 μM, respectively; P < 0.001; EdU, ~40% decrease at 150 μM, P < 0.001), and the number of colonies formed was significantly reduced (at 50 μM, P < 0.001). However, normal human astrocytes were more resistant to its cytotoxic effects (IC₅₀ >450 μM). Annexin-V/PI staining was increased indicating that GG induced apoptosis in GBM cells (26.67 and 30.42%, U87MG and U251, respectively) and associated proteins including BAX and cleaved PARP-1 were increased (~3×). Cells also underwent pyroptosis as determined under phase-contrast microscopy. Knockdown of gasdermin E (GSDME), a protein involved in pyroptosis, alleviated pyroptosis induced by GG through aggravating nuclear DNA damage in GBM cells. Meanwhile, fluorescent GFP-RFP-MAP1LC3B puncta associated with autophagy increased under GG treatment, and transmission electron microscopy confirmed the formation of autophagic vesicles. Inhibition of autophagy enhanced GG-induced apoptosis and pyroptosis in GBM cells. Finally, in an orthotopic xenograft model in nude mice derived from U87MG cells, treatment with GG in combination with an inhibitor of autophagy, chloroquine, suppressed tumor growth, and enhanced survival compared to GG monotherapy (P < 0.05). Our results demonstrated that GG simultaneously induces apoptosis, pytoptosis, and protective autophagy in GBM cells, indicating that combination treatment of GG with autophagy inhibitors may be an effective therapeutic strategy for GBM.

Natural alkaloids from lotus plumule ameliorate lipopolysaccharide-induced depression-like behavior: integrating network pharmacology and molecular mechanism evaluation

Depression is a mental disorder that brings severe burdens to patients and their families. Neuroinflammation and neurotrophins are involved in depression. Lotus plumule is a nutritional food with medicinal values. In the present study, we tried to clarify the anti-depressive effect and molecular mechanism of lotus plumule. Network pharmacological analysis, behavior tests, qRT-PCR and western blotting were used. We found 7 potential active components and 91 targets from the TCMSP database. KEGG analysis suggested that lotus plumule significantly affected nitrogen metabolism, calcium signaling, and inflammatory mediator regulation signaling pathways. Consistent with those effects, total alkaloids of lotus plumule (TLA) and active alkaloids differently suppressed the nitric oxide (NO) production and pro-inflammatory mediators. TLA and higenamine significantly ameliorated LPS-induced depression-like behavior, increased BDNF levels, suppressed microglia activation, and inhibited the expression of ER stress-related proteins. Meanwhile, TLA and higenamine activated microglia autophagy by increasing the beclin-1 and LC3B-II expression. Additionally, in the presence of autophagy inhibitor 3-MA, TLA and higenamine did not reduce the LPS-induced NO production or pro-inflammatory mediators. Collectively, TLA and higenamine attenuated LPS-induced depression-like behavior by regulating BDNF-mediated ER stress and autophagy. Therefore, drinking tea of lotus plumule may provide a potential strategy for preventing depression.

Anti-inflammatory effects of flavonoids

Inflammation plays a key role in diseases such as diabetes, asthma, cardiovascular diseases and cancer. Diet can influence different stages of inflammation and can have an important impact on several inflammatory diseases. Increasing scientific evidence has shown that polyphenolic compounds, such as flavonoids, which are found in fruits, vegetables, legumes, or cocoa, can have anti-inflammatory properties. Recent studies have demonstrated that flavonoids can inhibit regulatory enzymes or transcription factors important for controlling mediators involved in inflammation. Flavonoids are also known as potent antioxidants with the potential to attenuate tissue damage or fibrosis. Consequently, numerous studies in vitro and in animal models have found that flavonoids have the potential to inhibit the onset and development of inflammatory diseases. In the present review, we focused in flavonoids, the most abundant polyphenols in the diet, to give an overview of the most recent scientific knowledge about their impact on different inflammatory diseases.

Optimization of heteroatom doped graphene oxide by deep eutectic solvents and the application for pipette-tip solid-phase extraction of flavonoids

In order to improve the permeation and adsorption properties of graphene oxide, heteroatoms and deep eutectic solvent were introduced in this study. After being modified, the structural properties of graphene oxide were improved and the materials were applied to the determination of myricetin and rutin in tea sample by pipette-tip solid-phase extraction method. The materials were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-Ray diffractomer, energy dispersive spectroscopy, atomic force microscope, and specific surface area by Brunauer-Emmett-Teller N₂ adsorption desorption analysis. Meanwhile, they were tested by static and dynamic adsorption. The result showed that the materials after modifying had better adsorption amount for myricetin and rutin than graphene oxide. The calibration graphs of myricetin and rutin in MeOH were linear over 0.10-500.00 µg/mL, and the limits of detection and quantification were in the range of 0.00546-0.0182 µg/mL and 0.00741-0.0247 µg/mL, respectively. A reliable analytical method was developed for recognition targets in tea sample by DES modified nitrogen-doped graphene oxide with satisfactory extraction recoveries (myricetin 99.77%, rutin 98.14%). It was potential for the rapid purification of myricetin and rutin in tea sample combined with the pipette-tip solid-phase extraction.