•In silico proteolysis of bovine collagen released many ACE-inhibitory peptide sequences.•The ACE-inhibitory activities of in silico-derived peptides were predicted by QSAR models.•In silico peptides ...(YW and LRY) were experimentally verified as novel ACE inhibitors.•In vitro papain-catalysed digestion of bovine collagen also released ACE-inhibitory peptides.
In silico proteolysis using 27 proteases theoretically released numerous ACE-inhibitory peptides from collagen alpha-1(I) and alpha-2(I) sequences. Papain was the most effective protease to release ACE-inhibitory peptides. Two quantitative structure–activity relationship (QSAR) models for ACE-inhibitory peptides were established and employed to predict the activities of in silico-derived collagen peptides. Furthermore, two promising in silico peptides (Tyr-Trp and Leu-Arg-Tyr) derived from papain and bromelain digestion were synthesised and experimentally confirmed as novel ACE inhibitors. In vitro digestion of collagen by papain generated ACE-inhibitory peptides and the most active one was identified as a pentapeptide (Gly-Pro-Arg-Gly-Phe). However, Gly-Pro-Arg-Gly-Phe remained unidentified as the ACE-inhibitory peptide during the in silico digestion by papain mainly due to complete hydrolysis, which was not the case during in vitro digestion affected by external factors. Overall, the present study highlights bovine collagen as a promising precursor of ACE-inhibitory peptides by in silico and in vitro protein digestions.
Proteus mirabilis is known to cause Catheter-associated urinary tract infections (CAUTIs), which exhibit virulence factors linked to forming biofilms. Aptamers have recently been explored as ...potential anti-biofilm agents. This study demonstrates the anti-biofilm activity of aptamer (PmA2G02) targeting P. mirabilis 1429T, a pathogenic bacteria known to cause Catheter-associated urinary tract infections (CAUTIs). The studied aptamer inhibited biofilm formation, swarming motility, and cell viability at a concentration of 3 μM. The study also showed that the PmA2G02 had a binding affinity towards fimbrial outer membrane usher protein (PMI1466), flagellin protein (PMI1619), and regulator of swarming behavior (rsbA), which are responsible for adhesion, motility, and quorum sensing, respectively. Crystal violet assay, SEM, and confocal imaging confirmed the effectiveness of the PmA2G02 as an anti-biofilm agent. Moreover, as verified by qPCR, the expression levels of fimD, fliC2, and rsbA were significantly reduced compared to the untreated group. This study suggests that aptamer may be a potential alternative to traditional antibiotics for the treatment of CAUTIs caused by P. mirabilis. These findings shed light on the mechanisms by which the aptamer inhibits biofilm formation.
•Watermelon seed peptide was purified by using gel filtration and RP-HPLC.•Five novel watermelon seed peptides were identified.•Antioxidant activity of purified peptides and synthetic peptides were ...evaluated.
The aim of this study was to purify and identify antioxidant peptides from watermelon seed protein hydrolysates (WSPHs-I: Mw < 1 kDa) and further evaluate their cytoprotective effects against H2O2-induced oxidative stress in HepG2 cells. After purification by Sephadex G-15 and semi-preparative reversed-phase high performance liquid chromatography (RP-HPLC), five peptides, RDPEER (P1), KELEEK (P2), DAAGRLQE (P3), LDDDGRL (P4), and GFAGDDAPRA (P5) were sequenced by LC-MS/MS and synthesized with solid-phase synthesis method. These peptides showed desirable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity (IC50: 0.216 ± 0.01–0.435 ± 0.03), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacity (IC50: 0.54 ± 0.02–1.23 ± 0.03), and oxygen radical absorbance capacity (ORAC) (82.36 ± 1.2–130.67 ± 2.2 μM TE/mg). Among them, peptide P1 exhibited the strongest antioxidant capacity. Moreover, the results suggested that peptide P1 may protect HepG2 cells from H2O2-induced oxidative damage by significantly inhibiting reactive oxygen species (ROS), Ca2+i, malondialdehyde (MDA) levels and increasing antioxidative enzyme activities.
Parkinson's disease (PD) is a debilitating neurodegenerative condition characterized by the loss of dopaminergic neurons in substantia nigra. MPP+ as a dopaminergic neurotoxin induces many ...parkinsonian-like symptoms in cell culture. MicroRNAs are noncoding RNAs which their deregulation participates in neurodegeneration by affecting most of the mechanisms responsible for neurodegenerative diseases. Differentiated PC12 cells impaired by MPP+ were served as an in vitro model of PD. The aim of present research is to evaluate expression of several miRNAs and possible target genes in MPP+-treated differentiated PC12 cells. PC12 cells were differentiated by induction of NGF. Neurite outgrowth was quantified using image analysis software. MTS assay was served to assess cell viability. DCFH-DA assay and Annexin v staining were used to detect reactive oxygen species (ROS) levels and apoptosis, respectively. An in-silico study was performed to make interaction analysis between selected mRNAs and microRNAs. The expression levels of microRNAs and target genes were examined by RT-qPCR. NGF induced differentiation led to a substantial increase in neurite lengths means and percentage of the neurite-bearing cells. NGF-differentiated PC12 cells substantially expressed TH and retained their dopaminergic characteristic after differentiation. NGF treatment enhanced TH gene expression. MPP+ exposure caused loss of cell viability and induced apoptosis and ROS overproduction. SIRT1, BCL2, and BDNF were down-regulated after MPP+-treatment. In contrast, MPP+ toxicity significantly caused up-regulation in miR-34a, miR-141, and miR-9. The present study showed altered levels of selected microRNAs in response to MPP+ for the first time, suggesting that perturbed expression of them may contribute to the PD-related pathogenic processes, probably by affecting the expression of BCL2, BDNF, and SIRT1 as potential targets.
•MPP+ treatment induced up-regulation of miR-34a, miR-141, and miR-9.•SIRT1, BCL2, and BDNF were found to be down-regulated following MPP+ exposure.•Selected miRNAs and mRNAs were shown opposite expression patterns.
This investigation sought to identify antioxidative peptides derived from Meretrix meretrix L. (MML) throughout simulated gastrointestinal digestion (SGD) via in vitro and in silico strategies. The ...study demonstrated that hydrolysates from MML captured at various SGD phases showcased robust antioxidative activity. These hydrolysates also displayed a protective role against hydrogen peroxide-induced stress in Raw 264.7 cells. Notably, hydrolysates sourced from the intestinal phase of digestion (MMLHs-I) markedly inhibited the reduction of cell viability, limited the generation of reactive oxygen species under oxidative stress conditions, and promoted the activity of key antioxidant enzymes including superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, thus amplifying the cells' antioxidative defense system. Through nLC-MS/MS analysis, 105 peptides tracing back to 18 parent proteins were pinpointed in MMLHs-I, with 18 of these peptides previously reported in the BIOPEP-UWM database. Subsequent in silico analysis, alongside empirical antioxidant activity assays, pinpointed the peptide WLV as an exceptional antioxidative agent, demonstrating an IC50 of 0.125 mg/mL in the ABTS assay and an impressive 15.18 μmol Trolox/mg in the ORAC assay. The outcomes highlight MML's promise as a novel source of antioxidative peptides, positioning peptide WLV as a potentially valuable addition to functional foods designed to combat oxidative stress.
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•MMLHs-I exerted the best antioxidant activity among the SGD hydrolysates.•MMLHs exhibited protective effect on H2O2-stressed Raw 264.7 cells.•A total of 105 peptides were identified from MMLHs-I.•WLV exhibited excellent antioxidant activities in ABTS and ORAC assays.
Triacylglycerols (TAGs) are a primary energy source for marine mammals during lipid digestion. Walruses (Odobenus rosmarus divergens) consume prey with a high content of long-chain polyunsaturated ...fatty acids; however, their digestive physiology and lipid digestion remain poorly studied. The present study aims to model and characterize the gastric (PWGL) and pancreatic (PWPL) lipases of Pacific walruses using an in-silico approach. The confident 3D models of PWGL and PWPL were obtained via homology modeling and protein threading and displayed the structural features of lipases. Molecular docking analysis demonstrated substrate selectivity for long-chain TAG (Trieicosapentaenoin; TC20:5n-3) in PWGL and short-chain TAG (Trioctanoin; TC8:0) in PWPL. Molecular dynamics simulations demonstrate that PWGL bound to tridocosahexaenoin (TC22:6n-3), the protein is considerably stable at all three salinity conditions, but fluctuations are observed in the regions associated with catalytic sites and the lid, indicating the potential hydrolysis of the substrate. This is the first study to report on the digestion of TAGs in walruses, including modeling and lipases characterization and proposing a digestive tract for pinnipeds.
•Walrus gastric and pancreatic lipases exhibited high binding energy with long and short triacylglycerols, respectively.•Walrus gastric lipase revealed halotolerance based on molecular dynamics.•DHA-triacylglycerol (22:6n-3) could interact with active sites of walrus gastric lipase at slight and moderate salinity.•Proposal of triacylglycerols digestion in walrus: a highly conserved process
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•Partridge tea extracts (PTs) exhibited strong digestive enzymes inhibitory activity.•PTAEs evidently improved glucose consumption of 3T3L1 preadipocytes cells.•Digestive enzymes ...inhibitors (DEIs) in the PTAEs were screened by ultrafiltration-based LC/MS method.•Catechin, rutin, ferulic acid and kaempferitrin were the major DEIs in the PTAEs.•Inhibitory mechanisms of the major DEIs on digestive enzymes were clarified.
Partridge leaves (Mallotus furetianus Muell-Arg.) have long been consumed as popular folk substitute tea for treating hyperglycemia in China. In this study, the inhibiting effects of partridge tea extracts on α-glucosidase and α-amylase were investigated, and then effect of partridge tea aqueous extracts (PTAEs) on glucose consumption capacity of 3 T3-L1 preadipocytes cells was determined. Results verified that PTAEs showed excellent anti-α-glucosidase and anti-α-amylase effects. In addition, the PTAEs evidently promoted glucose consumption capacity of 3T3L1 preadipocytes cells. To this end, a combined method of affinity ultrafiltration and HPLC-ESI-qTOF-MS/MS was used for rapidly screening and identifying the potential inhibitors in the PTAEs. Catechin, epicatechin, rutin, ferulic acid, and kaempferitrin with high affinity capacity indicated strong inhibiting effect on α-glucosidase and α-amylase. Docking studies revealed the potential interactive mechanisms between these major inhibitors and two digestive enzymes. This research shows that partridge tea is effective in preventing and treating post hyperglycemia.
•TMHMS is a natural anticancer stilbene that targets tubulin polymerization.•TMHMS was used to create 28 coumarins with improved medicinal effects.•The tested were anticancer, antioxidant, ...anti-inflammatory, and biosafety studies.•Coumarin-structural modification can offer potent and biosafe TMHMS derivatives.•This study afforded many insights about the SAR of the synthesized coumarins.
3,4,5-Trimethoxy-3′-hydroxy-4′-methoxystilbene (TMHMS) is an anticancer natural stilbene that targets tubulin polymerization. According to research, oxidative stress and inflammation are linked to cancer, and lowering both of these hazards may have a detrimental influence on tumor development. TMHMS was used as a building block in this investigation to generate 28 coumarins with increased medicinal value. TMHMS-COU-1, the first coumarin derivative, was activated by thionyl chloride and subsequently linked with different phenols, yielding 27 TMHMS-COU variants. This natural product was used as a reference for oxidative stress-alleviated activities such as anticancer activity against eight cancerous cellular lines, antioxidant activity on H2O2-treated human SH-SY5Y populations, and anti-inflammatory activity against three enzyme-based representatives of inflammation. TMHMS and its coumarins were tested for their impact on the normal development of three cell types as well as human erythrocyte hemolysis in biocompatibility tests. Finally, utilizing two web-based programs, the pharmacokinetic profiles of the building component and its variants were computed. The inclusion of an electron-donating group on the off-side aromatic ring directly boosted the oxidative stress-alleviated activities, according to the results. These activities were also boosted when this group occupied the para or meta position. When this aromatic ring was trisubstituted with this group type, the greatest activities were found, with the trimethoxy aromatic ring having preferential activities. In terms of biocompatibility, the synthesized coumarins showed a high level of compatibility with the tested normal cells as well as human erythrocytes. Furthermore, the in silico research confirmed the synthesized coumarins' ability to provide prospective therapeutic candidates. According to the author, the coumarin-structural change might open the way for the development of novel, powerful, and biosafe TMHMS derivatives. This work provided various insights into the structure-function connections that can direct subsequent studies on TMHMS-based derivatives.
Cadmium (Cd) adversely affects the yield and quality of rice. It is, therefore, crucial to elucidate the consequences of Cd toxicity. Plant height, biomass, SPAD score, PSII efficiency, and ...photosynthetic performance index were all significantly reduced in Cd-stressed rice. Cd stress resulted in a simultaneous increase in Cd and Fe concentrations in both the roots and the shoots, accompanied by the significant upregulation of heavy metal ATPase (OsHMA2, OsHMA3), natural resistance-associated macrophage proteins (OsNramp1, OsNramp5), Fe-regulated transporters (OsIRT1), Fe-reductase oxidase (OsFRO1) genes, and FCR activity in roots. This implies that Cd uptake may be closely associated with Fe transporters resulted in physiological and photosynthetic damages in Cd-stressed rice. In silico analysis suggested that the localization of Cd-uptake proteins in the plasma membrane exhibiting transporter activity, among which two motifs were linked to the pfam_fs: Nramp domain. In a phylogenetic tree, HMA and Nramp genes were consistently positioned in the same cluster, while OsIRT1 and OsFRO1 were independently located. The key cis-acting elements were abscisic acid-responsiveness, methyl jasmonate-responsiveness, zein metabolism regulation, stress-responsiveness, salicylic acid-responsiveness, and gibberellin-responsiveness. An interactome map revealed the diverse functional partners of Cd-uptake genes, including MTP1 (metal tolerance protein 1), YSL6 (metal-nicotianamine transporter), IRO2 (Fe-regulated transcription factor 2), OsJ_16707 (a vacuolar Fe transporter homolog), YSL15 (an Fe-phytosiderophore transporter), and NAS2 (nicotianamine synthase), which were predominantly linked to Fe homeostasis. These findings greatly elucidate the Cd uptake mechanism in rice plants and can help to regulate Cd uptake either by breeding or silencing these transporters.
•Cd-toxicity severely affected plant biomass, chlorophyll synthesis, and PSII efficiency in rice.•Cd stress caused a simultaneous increase of Cd and Fe in both root and shoot tissues.•Results suggest the involvement of a common channel involving Cd and Fe uptake in Cd-stressed rice.•Cd-uptake genes in rice have a close partnership with MTP1, YSL6, IRO2, OsJ_16707, YSL15, and NAS2.•Abscisic acid and salicylic acid cis-acting elements are possibly involved in the regulatory process in Cd-stressed rice.
