Cell penetrating peptides: Highlighting points in cancer therapy.

Cell-penetrating peptides (CPPs), first identified in HIV a few decades ago, deserved great attention in the last two decades; especially to support the penetration of anticancer drug means. In the drug delivery discipline, they have been involved in various approaches from mixing with hydrophobic drugs to the use of genetically conjugated proteins. The early classification as cationic and amphipathic CPPs has been extended to a few more classes such as hydrophobic and cyclic CPPs so far. Developing potential sequences utilized almost all methods of modern science: choosing high-efficiency peptides from natural protein sequences, sequence-based comparison, amino acid substitution, obtaining chemical and/or genetic conjugations, in silico approaches, in vitro analysis, animal experiments, etc. The bottleneck effect in this discipline reveals the complications that modern science faces in drug delivery research. Most CPP-based drug delivery systems (DDSs) efficiently inhibited tumor volume and weight in mice, but only in rare cases reduced their levels and continued further processes. The integration of chemical synthesis into the development of CPPs made a significant contribution and even reached the clinical stage as a diagnostic tool. But constrained efforts still face serious problems in overcoming biobarriers to reach further achievements. In this work, we reviewed the roles of CPPs in anticancer drug delivery, focusing on their amino acid composition and sequences. As the most suitable point, we relied on significant changes in tumor volume in mice resulting from CPPs. We provide a review of individual CPPs and/or their derivatives in a separate subsection.

Toad venom bufadienolides and bufotoxins: An updated review.

Bufadienolides, naturally found in toad venoms having steroid-like structures, reveal antiproliferative effects at low doses. However, their application as anticancer drugs is strongly prevented by their Na+ /K+ -ATPase binding activities. Although several kinds of research were dedicated to moderating their Na+ /K+ -ATPase binding activity, still deeper fundamental knowledge is required to bring these findings into medical practice. In this work, we reviewed data related to anticancer activity of bufadienolides such as bufalin, arenobufagin, bufotalin, gamabufotalin, cinobufotalin, and cinobufagin and their derivatives. Bufotoxins, derivatives of bufadienolides containing polar molecules mainly belonging to argininyl residues, are reviewed as well. The established structures of bufotoxins have been compiled into a one-page figure to review their structures. We also highlighted advances in the structure-modification of the structure of compounds in this class. Drug delivery approaches to target these compounds to tumor cells were discussed in one section. The issues related to extraction, identification, and quantification are separated into another section.

Diversity and Biological Activities of Endophytic Fungi from the Flowers of the Medicinal Plant Vernonia anthelmintica.

Secondary metabolites produced by endophytic fungi are an important source of biologically active compounds. The current research was focused on the biological activities of ethyl acetate extracts of fungi, isolated and identified from Vernonia anthelmintica flowers for the first time. In addition, an investigation of the non-polar chemical composition of dichloromethane-ethyl acetate extracts of the most active fungal strain was carried out. The isolates included Ovatospora senegalensis NR-03, Chaetomium globosum NR-04, Thielavia subthermophila NR-06, Aspergillus calidoustus NR-10, Aspergillus keveii XJF-23 and Aspergillus terreus XJF-3 species. Strains were identified by 18S rRNA gene sequencing methods and were registered in GenBank. Crude extracts of the fungi displayed in vitro biological activities, including antimicrobial and cytotoxic activities. A melanin content assay was performed on murine B16 cells. An ethyl acetate extract of O. senegalensis NR-03 showed high anticancer and antimicrobial activity; therefore, we also studied the non-polar chemical composition of the dichloromethane-ethyl acetate fraction and identified 52 non-polar compounds with the different medium. This investigation discovered that the secondary metabolites of the total extract of endophytic fungi could be a potential source of alternative natural antimicrobial, cytotoxic and melanin synthesis activity in their host plant, and the isolation of bioactive metabolites may provide a lead to new compounds of pharmaceutical significance.

Isolation, Structural Elucidation, Antioxidant and Hypoglycemic Activity of Polysaccharides of Brassica rapa L.

The aim of this study was to investigate the effects of microwave ultrasonic-assisted extraction (MUAE) on the content, structure, and biological functions of Brassica rapa L. polysaccharide (BRP). Response surface methodology (RSM) was used to optimize the parameters of MUAE, and it obtained a polysaccharide with yield of 21.802%. Then, a neutral polysaccharide named BRP-1-1 with a molecular weight of 31.378 kDa was isolated and purified from BRP using DEAE-650 M and Sephadex G-100. The structures of the BRP-1-1 were elucidated through a combination of FT-IR, GC-MS, NMR, and methylation analysis. The results showed that BRP-1 consisted of mannose (Man) and glucose (Glu) in a molar ratio of 7.62:1. The backbone of BRP-1-1 mainly consisted of →6)-α-D-Glup-(1→4-ß-D-Glup-(1→2)-α-D-Manp-(1→2)-α-D-Glup-(1→, the branch was [T-α-D-Manp-(1]n→. BRP-1-1 intervention significantly inhibited α-glucosidase activity; an inhibition rate of 44.623% was achieved at a concentration of 0.5 mg/mL. The results of the in vitro biological activity showed that BRP-1-1 has good antioxidant and hypoglycemic activity, suggesting that BRP-1-1 could be developed as a functional medicine.

Isolation, Structural Characterization, and Biological Activity of the Two Acidic Polysaccharides from the Fruits of the Elaeagnus angustifolia Linnaeus.

Elaeagnus angustifolia Linnaeus is a medicinal plant and its fruit has pharmacological activity such as antiinflammatory, antiedema, antinociceptive, and muscle relaxant functions, etc. Two acidic homogeneous polysaccharides (EAP-H-a1 and EAP-H-a2) were isolated from the fruits of Elaeagnus angustifolia L. through DEAE-52 and Sephadex G-75 column chromatography, and the physicochemical, structural properties, and biological activities of the polysaccharides were investigated. Both EAP-H-a1 and EAP-H-a2 were composed of Rha, Ara, Xyl, Glc, and Gal with the molar ratios of 13.7:20.5:23.3:8.8:33.4 and 24.8:19.7:8.2:8.4:38.6, respectively, and with the molecular weights of 705.796 kDa and 439.852 kDa, respectively. The results obtained from Fourier transform infrared spectroscopy (FTIR) confirmed the polysaccharide nature of the isolated substances. Congo red assay confirmed the existence of a triple-helix structure. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis revealed that EAP-H-a1 and EAP-H-a2 had irregular fibrous, filament-like surfaces; and both had crystalline and amorphous structures. Bioactivity analysis showed that the crude polysaccharide, EAP-H-a1, and EAP-H-a2 had clear DPPH and ABTS free radical scavenging activity, and could promote the secretion of NO and the phagocytic activities of RAW 264.7 and THP cells, which showed clear antioxidant and immuno-regulatory activity. These results indicated that Elaeagnus angustifolia L fruit acidic polysaccharides may have potential value in the pharmaceutical and functional food industries.

A designed antifungal peptide with therapeutic potential for clinical drug-resistant Candida albicans.

Due to the increasing drug-resistant of Candida albicans (C. albicans), there is an urgent need to develop a novel therapeutic agent for C. albicans induced inflammatory disease treatment. Antimicrobial peptides (AMPs) are regarded as one of the most promising antifungal drugs. However, most of the designed AMPs showed side-effects. In the present study, 10 novel peptides were designed based on the sequence of frog skin secretions peptide (Ranacyclin AJ). Among them, AKK8 (RWRFKWWKK) exhibited the strongest antifungal effect against both standard and clinically isolated drug-resistant C. albicans. AKK8 killed C. albicans (within 30 min), and the antifungal effect lasted for 24 h, showed an efficient and long lasted antifungal effect against C. albicans. Notably, AKK8 showed low toxicity to human red blood cells and high stability in human serum. Moreover, AKK8 administration showed therapeutic effects on systemic infections mice induced by the clinical drug-resistant C. albicans, in a dose-depended manner. These findings suggested that AKK8 may be a potential candidate for the anti-inflammation treatments for diseases caused by clinical drug-resistant C. albicans.

Endophytic Bacteria Associated with Medicinal Plant Vernonia anthelmintica: Diversity and Characterization.

Increasing evidence shows that endophytic bacteria living inside plant tissue may possess similar biological activity and produce similar metabolites to their hosts. This study aimed to determine the diversity of endophytic bacteria associated with Vernonia anthelmintica and to evaluate their biological activity. The bacteria were isolated from the plant tissue using culture-dependent techniques. Comparison of the 16S rRNA gene sequences of endophytic bacteria isolated from V. anthelmintica showed that isolates belong to the species Micrococcus endophyticus VERA1, Bacillus megaterium VERA2, Pseudomonas chlororaphis VERA3, P. kilonensis VERA4, Stenotrophomonas pavanii VERA5, B. endophyticus VERA6, S. maltophilia VERA7, Pantoea ananatis VERA8, B. atrophaeus VERA9 and M. flavus VERA10. Activity studies showed that the endophytic bacteria share several similar biological properties with their host plant including antimicrobial, anti-vitiligo and antidiabetic activities. These findings indicate that plant phytochemical compounds and activity play an important role in the physiological properties of their endophytes.

Optimization of Scorpion Protein Extraction and Characterization of the Proteins' Functional Properties.

Scorpion has long been used in traditional Chinese medicine, because whole scorpion body extract has anti-cancer, analgesic, anti-thrombotic blood anti-coagulation, immune modulating, anti-epileptic, and other functions. The purpose of this study was to find an efficient extraction method and investigate some of physical and chemical parameters, like water solubility, emulsification, foaming properties, and oil-holding capacity of obtained scorpion proteins. Response surface methodology (RSM) was used for the determination of optimal parameters of ultrasonic extraction (UE). Based on single factor experiments, three factors (ultrasonic power (w), liquid/solid (mL/g) ratio, and extraction time (min)) were used for the determination of scorpion proteins (SPs). The order of the effects of the three factors on the protein content and yield were ultrasonic power > extraction time > liquid/solid ratio, and the optimum conditions of extraction proteins were as follows: extraction time = 50.00 min, ultrasonic power = 400.00 w, and liquid/solid ratio = 18.00 mL/g. For the optimal conditions, the protein content of the ultrasonic extraction and yield were 78.94% and 24.80%, respectively. The solubility, emulsification and foaming properties, and water and oil holding capacity of scorpion proteins were investigated. The results of this study suggest that scorpion proteins can be considered as an important ingredient and raw material for the creation of water-soluble supramolecular complexes for drugs.

Isolation and Evaluation of Bioactive Protein and Peptide from Domestic Animals' Bone Marrow.

In this work, proteins and peptides were isolated from four kinds of animal bone marrow and characterized by sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and liquid chromatography-mass spectrometry (LC/MS). The antimicrobial and antioxidant activity of these proteins were investigated in vitro. The nutritional value was evaluated by analyzing their free amino acid composition. The results indicates that all of the extracts appeared two bands at SDS-PAGE, the peptide band at 4.1⁻10 kDa and protein band at 66 kDa, these data are consistent with LC/MS results. FT-IR analysis showed that the secondary structure of protein mainly consists of α-helix. SEM micrographs revealed that the fractions have different morphological characteristics. Horse bone marrow protein (HBMP) showed the highest antioxidant activity to DPPH free radical, IC50 value was 0.573 mg/mL. Most of the obtained fractions showed antimicrobial activities towards Escherichiacoli (EC) and Candida albicans (CA). Total free amino acid content ranged between 5.15⁻49.60 mg/g, and among them, HBMP displayed the highest abundance, 49.7 mg/g, which amino acid composition ratio approached the Food and Agriculture Organization/World Health Organization (FAO/WHO) ideal amino acid pattern recommendation. This study provides fundamental knowledge and a basic study method for the research into and development of animal bone marrow proteins and peptides as functional food and drug resources.

Rapid Quantification and Quantitation of Alkaloids in Xinjiang Fritillaria by Ultra Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry.

The Fritillaria genus, including different kinds of medicinal and edible plants belonging to the Liliaceae family which have the function of treating and relieving a cough and eliminating phlegm, is widely planted in Xinjiang (China). There are few comprehensive studies reporting on the characterization of the chemical constituents of Fritillaria from Xinjiang, and to date, no work describing the quantitative differences between the components in Fritillaria from Xinjiang and related species. The purpose of this study was to develop qualitative and quantitative analytical methods by Ultra Performance Liquid Chromatography-Quadrupole Time-of-flight Mass Spectrometry (UPLC-QTOF-MS) for the rapid quantification and quantitation of alkaloids in wild and cultivated Xinjiang Fritillaria, which could be used in the quality control of medicine based on this natural herb. Using the UPLC-QTOF-MS method, the chemical constituents of Xinjiang Fritillaria were identified by fragmentation information and retention behavior, and were compared to reference standards. Furthermore, a quantitative comparision of four major alkaloids in wild and cultivated Xinjiang Fritillaria was conducted by determining the content of Sipeimine-3ß-d-glucoside, Sipeimine, Peimisine, and Yibeinoside A, respectively. A total of 89 characteristic peaks, including more than 40 alkaloids, were identified in the chromatographic results of Fritillaria. Four main alkaloids were quantified by using a validated method based on UPLC-QTOF-MS. The relative contents of Sipeimine-3ß-d-glucoside, Sipeimine, Peimisine, and Yibeinoside A varied from 0.0013%~0.1357%, 0.0066%~0.1218%, 0.0033%~0.0437%, and 0.0019%~0.1398%, respectively. A rough separation of wild and cultivated Fritillaria could be achieved by the cluster analysis method.

New isosteroidal alkaloids with tracheal relaxant effect from the bulbs of Fritillaria pallidiflora Schrenk.

Four new isosteroidal alkaloids, yibeinones A-D (1-4), along with four known ones, imperialine-3ß-d-glucoside (5), imperialine (6), imperialine ß-N-oxide (7), and dongbeinine (8), were isolated from the bulbs of Fritillaria pallidiflora. Their structures were confirmed on the basis of extensive spectroscopic analysis or comparison with the data in the literatures (known compounds). Compounds 2, 3, 4, and 6 showed an apparent concentration-dependant relaxation of isolated tracheal preparation, amongst 3 and 6 exhibited significant effects with pA2 values of 6.19 ± 0.02 and 8.41 ± 0.10, and EC50 values of 0.65 ± 0.02 µmol L(-1) and 4.40 ± 0.90 nmol L(-1), respectively.

Arenobufagin, isolated from Bufo viridis toad venom, inhibits A549 cells proliferation by inducing apoptosis and G2/M cell cycle arrest.

Lung cancer is a significant contributor to cancer morbidity and mortality globally. Arenobufagin, a compound derived from Bufo viridis toad venom, has demonstrated the ability to inhibit cell growth in various cancer cell lines. However, our understanding of the role and mechanism of arenobufagin in lung cancer remains incomplete, necessitating further researches to fully elucidate its action mechanism. In this study, we further explored the impact of arenobufagin on A549 cells. The results revealed that it exerted a potent cytotoxic effect on A549 cells by inhibiting cell colony formation, promoting cell apoptosis, increasing reactive oxygen species (ROS) levels, and arresting A549 cells in G2/M phase. Collectively, our findings suggested that arenobufagin may have potential as a future therapeutic for lung cancer treatment.

The structural characteristic of acidic-degraded polysaccharides from seeds of Plantago ovata Forssk and its biological activity.

In this study, a response surface methodology (RSM) was used to determine the best combination for acid degradation parameters to reduce the viscosity of Plantago ovata Forssk seed polysaccharide (POFP). Then, the two major homogeneous polysaccharides (AH-POFP1 and AH-POFP3) were obtained by DEAE-650 M and Sephadex G-100 column chromatography. The apparent structure of the main fraction AH-POFP1 was characterized by SEM, TG and XRD, and the linkage of AH-POFP1 was determined by a combination of partial acidolysis, Smith's degradation, methylation analysis and 2D NMR analysis. Structural analysis showed that AH-POFP1 was mainly composed of xylose, with a molecular weight of 618.1 kDa, and had a backbone of 1 â†’ 4-linked Xylp, as well as branches of T-linked Xylp, 1 â†’ 4-linked Xylp attached to the O-2 position. The antioxidant activity assays showed that the both AH-POFP1 and AH-POFP3 possess strong scavenging radical ability. Moreover, AH-POFP1 inhibits the secretion of pro-inflammatory factors, and promotes the secretion of anti-inflammatory factors, thereby exerting anti-inflammatory effects. These findings may help to guide future applications of Plantago ovata Forssk in the fields of food, health care, and pharmacy.

Two new polyamine alkaloids from the Bufo viridis toad venom.

Two new polyamine alkaloids (bufonines A-B), together with four known alkaloids, bufotenidine (3), bufotenine (4), 1-(ß-d-ribofuranosyl)-lH-1,2,4-triazone (5) and proline (6) were isolated from the Bufo viridis toad venom. Their structures were identified by UV, HR-ESI-MS, NMR spectral analyses, and comparison of theoretical and experimental ECD data. All compounds were tested in vitro cytotoxicity against three human cancer cell lines (HT-29, A549 and Hela). None of the compounds showed cytotoxicity towards all tested cell lines. To the best of our knowledge, this is the first report of alkaloid components from Bufo viridis toad venom.

Bufadienolides from the Bufo viridis toad venom exert cytotoxic effects on cancer cells by inducing cell apoptosis and cell cycle arrest.

A series of bufadienolides were isolated from the Bufo viridis toad venom, and their cytotoxic activities against three human cancer cell lines (HeLa, HT-29, MCF7) and a non-cancer cell line (L-O2) were explored using the MTT assay in vitro. All of nine compounds exhibited cytotoxic activities against the three cancer cell lines, with compound D4 exhibiting potent cytotoxic activity against HeLa cells and was better than positive control. Herein, we further evaluated the effect of compound D4 on HeLa cells. The results revealed that compound D4 has excellent cytotoxic effect on HeLa cells by inhibiting cell colony formation and migration, promoting cell apoptosis, increasing reactive oxygen species (ROS) levels and arresting of HeLa cells in S and G2/M phases. These findings encourage further work on the chemistry and bioactivity of the Bufo viridis toad venom.

Synthesis and Characterisation of Chickpea Peptides-Zinc Chelates Having ACE2 Inhibitory Activity.

Tryptic hydrolysates of protein fractions obtained by the Osborne method from chickpea (Cicer arietinum L.) seeds interacted with zinc ions and the results of chelation were monitored by the Energy Dispersive X-Ray (EDX) technique. The glutelin hydrolysate (GluHyd) reacted with zinc ions and depicted a relatively higher zinc content. For this reason, the zinc complex of the glutelin hydrolysate (GluHyd-Zn) was studied deeper, and 11 peptides were identified in its more zinc-containing second fraction obtained after gel filtration. The peptide HKERVQLHIIPTAVGK showed a relatively higher chelating capacity (57.86 ± 2.14%). According to the result of the ICP-OS analysis, 1 mg peptide could chelate 381.61 ± 133.39 µg zinc, and the molar ratio of peptide-zinc was about 1:4. Spectral methods proved that side chain and C-termini carboxyl groups of the peptide mostly were involved in chelation and N atoms of amino side chains, imidazole group of histidine, and N-termini at some extents were occupied by the metal ions. Modeling of zinc-peptide interaction was done using Molecular Operating Environment (MOE) software. The results of the docking correlate with the experimental data.ACE2 inhibitory effect of HKERVQLHIIPTAVGK-Zn complex (IC50 = 1.5 mg/mL) was better than that of HKERVQLHIIPTAVGK (IC50 = 2.2 mg/mL).

Biochemical characterization, and anti-inflammatory and antitumor activities of glycoprotein from lamb abomasum.

ETHNOPHARMACOLOGICAL RELEVANCE: Lamb abomasum is used as an edible medicinal source in traditional Chinese medicine for the treatment of gastrointestinal disorders. Lamb abomasum sourced biochemical drug Lamb's trip extract and Vitamin B12 capsule used for the clinical treatment of chronic gastritis, gastric ulcer, and reversal of intestinal metaplasia. Therefore, claimed to have prevention of gastric cancer activity. AIM OF THE STUDY: In this study, we aim to assess whether the glycoprotein has biological activity in the cure of gastric disorder and conduct a structure-activity relationship. MATERIALS AND METHODS: Glycoproteins' extraction conditions were optimized by the response surface method and purified with DEAE-cellulose and Sephadex G-50 chromatography. Two homogenous glycoproteins' physiochemical structures were studied with electrophoresis, HPLC analysis, peroxide oxidation, and ß-elimination, FT-IR, CD, LC-MS/MS, and EDS analysis. The antiinflammation activity of the glycoprotein was determined against COX-2 and LOX-15 enzyme inhibitory ability in vitro, and antitumor activity against HT-29 and HGC-25, and cytotoxicity on L-02 cells was determined in vivo with the MTT method. RESULTS: The abomasum was abundant in glycoprotein and the extraction yield of glycoprotein was up to 24.6 ± 2.1% under optimized conditions. Two homogeneous glycoproteins SAGP-I and SAGP-II determined to be ribose-conjugated and sulfated glycoproteins with a molecular weight of 15.6 kDa and 6.4 kDa. And according to the structural analysis, SAGP-I was a mucin-type ribose-conjugated glycoprotein with 14 O-glycosylation and one N- glycosylation site. SAGP-I and SAGP-II have remarkable anti-inflammatory activity against COX-2 enzyme with the IC50 of 17.64 ± 1.25 µg/mL and 16.14 ± 1.11 µg/mL, respectively. Meanwhile, the two glycoproteins showed strong antitumor activity against HT-29 with the EC50 of 19.19 ± 1.46 µg/mL and 184.9 ± 5.6 µg/mL, respectively. CONCLUSION: The Highly purified glycoprotein SAGP-1 and SAGP-II showed anti-inflammatory activity against the COX-2 enzyme, and antitumor activity against HT-29 human colon cancer cells and noun-inhibitory activity against LOX-15 enzyme and HGC-25. Both glycoproteins are ribose conjugated and sulfated whose characters are related to their anti-inflammatory and anti-tumor activity. Such results suggest the possibility of anti-inflammatory and pre-cancer activity. And in some degree explains the pharmacy of abomasum's traditional use in gastric disorder and clinical use of lamb abomasum APIs drugs' in gastric disorders and gastric cancer development. This study provides a preliminary basis for the further study of the per-cancer mechanism of lamb abomasum glycoprotein. And, would be the material basis of the clinical use of Lamb's trip extract and Vitamin B12 capsule.

Bioassay-guided isolation of antioxidants from Astragalus altaicus by combination of chromatographic techniques.

An efficient method for bioassay-guided preparative isolation of antioxidants from the n-butanol extract of Astragalus altaicus Bunge was ingeniously developed by combination of silica gel column chromatography and high-speed counter-current chromatography. Under the bioassay-guidance of antioxidant activities, the antioxidants were gradually separated from the crude sample of Astragalus altaicus Bunge by silica gel column chromatography and high-speed counter-current chromatography. Silica gel column chromatography separation was performed with chloroform, chloroform-methanol (100:1~5:1, v/v) and chloroform-methanol-water (5:1:0.1~2:1:0.1, v/v/v). High-speed counter-current chromatography separation was performed with a two-phase solvent system composed of ethyl acetate-n-butanol-water (2:1:6, v/v/v), which was successfully selected by thin layer chromatography analysis, at a flow rate of 1.5 mL/min. As a result, isorhamnetin-3-gentiobioside (20.8 mg), rutin (82.0 mg), and narcissin (12.8 mg) were obtained for the first time from 200 mg of the crude sample, ABS-5 of Astragalus altaicus Bunge. The purities were all at over 95% by high-performance liquid chromatography analysis, and their structures were unambiguously identified by mass spectroscopy, (1) H, and (13) C nuclear magnetic resonance spectroscopy. Antioxidant activities of the three compounds were also assayed by in vitro ABTS [2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diamonium salt] radical cation scavenging activity. Among them, rutin possessed the highest antioxidant capacity with SC(50) value of 22.15 µg/mL.

Unusual ring B-seco isosteroidal alkaloid, yibeiglycoalkaloids A-E from Fritillaria pallidiflora schrenk.

Five previously undescribed steroidal glycoalkaloids(SGAs)and a rare ring B-seco isosteroidal alkaloid, were isolated from Fritillaria pallidiflora Schrenk, along with six known alkaloids. The structures of these alkaloids were established by comprehensive analyses of the 1D, 2D-NMR and HR-ESI-MS data. Configurations of sugar moieties were resolved by chemical derivations. The isolated compounds showed nitric oxide (NO) inhibitory activities in lipopolysaccharide (LPS) induced RAW264.7 cells, and yibeinone exhibited the strongest inhibitory effects among them. This study revealed that the alkaloids from F. pallidiflora might have significant anti-inflammatory potentials.

Covalent binding of flavonoids with silk sericin hydrolysate: Anti-inflammatory, antioxidant, and physicochemical properties of flavonoid-sericin hydrolysate conjugates.

To construct food ingredients with improved bioactivities and physicochemical properties, two sericin hydrolysate-flavonoid conjugates, bearing quercetin and rutin covalently bound to sericin, were prepared under alkaline conditions. UV spectroscopy and SDS-PAGE confirmed that sericin hydrolysate and oxidized flavonoids formed conjugates, which were primarily the result of covalent interactions. Changes and differences in molecular weight distribution, secondary and tertiary structures, surface hydrophobicity, and surface morphology were observed. Anti-inflammatory activities were evaluated by basing on inhibitory activity against nitric oxide (NO) production and 15-lipoxygenase (15-LOX). The conjugates showed significantly improved (p < .05) anti-inflammatory and emulsifying properties than unmodified sericin hydrolysate. Meanwhile, the covalent interaction had a positive effect on the antioxidant activity of sericin hydrolysate. PRACTICAL APPLICATIONS: We had prepared flavonoid-sericin hydrolysate conjugates and evaluated the effect of covalent binding of flavonoids on the physicochemical, anti-inflammatory, antioxidant, and emulsifying properties of sericin hydrolysate, which is beneficial to broaden the range of applications of sericin and flavonoids in the food, cosmetics, and pharmaceutical industries.