Antioxidative Responses in Banana (Musa Sp.) Cultivars Under Water Stress

Responses of the enzymatic and non-enzymatic antioxidant defence systems as well as oxidative injury in banana ptants (Musasp.) subjected to polyethylene glycol (PEG)-induced water stress were investigated. Micropropagated plantlets of two banana cultivars, '8erangan' and 'Mas' were subjected to 0%, 10%, 20% and 40% PEG 6000 treatments in vitro for a duration of 14 days. Progressive decline in the leaf water content of both cultivars with time and increased concentrations of PEG used, indicates that water stress was successfully imposed. Based on the enhanced levels of lipid peroxidation and membrane permeability, this study shows that water stress resulted in oxidative injury in both cultivars. Relatively lower level of membrane leakage and malondialdehyde concentrations in 'Berangan' indicate that it was more tolerant than 'Mas' to water stress-induced oxidative damage

Investigation on the Effects of Hydroponic-planting Versus Soil-planting Using Plectranthus amboinicusas a Plant Model

Hydroponic system is a method of growing crops or plants in a soilless system, by suspending the plant crops in a nutrient-rich solution, with reduced interferences from factors such as soil quality, irrigation and climate. However, there is limited infor-mation available on how hydroponic planting will affect the plant’s bioactivities, as well as the associated biochemical, mineral, phytochemical and antioxidant enzyme contents. In this study, we used Plectranthus amboinicus(Indian borage) as a medic-inal plant model, to investigate the differences between hydroponic-planted (HP) ver-sus soil-planted (SP) plants. Here, aqueous extracts of Indian borage from HP and SP samples were prepared, followed by testing for their phytochemical, mineral, chloro-phyll and carotenoid contents. Based on our results, SP sample was detected with higher antioxidant potentials, using two different radical scavenging assays. This ob-servation is correlating to the higher phytochemical contents (total phenolic, flavo-noid, and hydroxycinnamic acids contents), as well as higher chlorophyll and carote-noid contents, detected in the SP sample. However, no significant difference was de-tected between HP and SP samples, in terms of their protein protection potentials. On the other hand, HP sample was tested with higher mineral contents (iron, copper, mag-nesium and calcium) using the atomic absorption spectroscopy method. Additionally, higher antioxidative enzymes (superoxide dismutase, catalase) were also detected in the HP sample using in vitrobiochemical assays. In the future study, more plant mod-els can be included in the comparison between HP and SP effects, to determine if a similar phenomenon is observed. Through similar studies, more related information could be gathered to guide the choice of suitable planting systems with regard to food security, in terms of both harvest yields and nutritional contents

Protein Profiling of Orthosiphon stamineusEmbryogenic Callus using Liquid Chromatography Coupled with Tandem-Mass Spectrometry (LC-MS/MS)

Orthosiphon stamineusis one of the most prominent medicinal herbs widely grown in Southeast Asia. Propagation of O. stamineus using tissue culture technique helps to rapidly produce samples for research purposes, increase the production of secondary metabolites and is considered as one of the strategies in plant genetic improvement. Despite vast information on O. stamineuspharmacological properties, the protein pro-file of this species is currently underexplored. In the present study, proteins expressed in embryogenic callus developed from O. stamineusleaves in Murashige and Skoog medium supplemented with 1-naphthaleneacetic acid(NAA) and 2,4-dichlorophe-noxyacetic acid (2,4-D) were identified via Liquid chromatography-tandem mass spectrometry (LC-MS/MS). The presence of embryogenic callus was confirmed with microscope observation and Evan Blue assay. Using this proteomic approach, we identified peptides that represent 22 proteins localizedto different cell compartments and involved in various biological and metabolic functions in plants. This finding is useful to improve our understanding of protein functions, thus their future applications could be further explored

Alpha-Glucosidase Inhibitory and Antioxidant Activity of Solvent Extracts and Fractions of Typha domingensis (Typhaceae) Fruit

Purpose: To identify a solvent fraction with potent antiglucosidase and antioxidant activities from the fruit of Typha domingensis.Methods: Extracts were prepared using hexane, chloroform, ethyl acetate, acetone (AE), methanol, and water. Antiglucosidase and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of extracts were assessed. The most active extract was partitioned into chloroform, ethyl acetate, butanol (BF) and water, and the antiglucosidase and radical scavenging activities of the fractions were determined. Mode of inhibition of the strongest antiglucosidase fraction was investigated. Polyphenol, coumarin, proanthocyanidin (TPro), and hydroxycinnamic acid contents of the extracts and fractions were evaluated.Results: AE had the highest antiglucosidase (EC50 = 12.36 μg/mL) and radical scavenging (EC50 = 8.57 μg/mL) activities. Solvent-partitioning of AE resulted in BF, which showed markedly stronger antiglucosidase activity (EC50 = 4.27 μg/mL) than quercetin (EC50 = 22.18 μg/mL). BF also had potent radical scavenging activity (EC50 = 7.20 μg/mL). BF was rich in TPro (735.65 mg/g) and was a competitive glucosidase inhibitor. TPro content correlated with antiglucosidase (R2 = 0.709) and DPPH scavenging activities (R2 = 0.838).Conclusion: TPro-rich BF of T. domingensis fruit is a highly potent glucosidase inhibitor and radical scavenger. The findings demonstrate a potential for the development of natural antihyperglycemic agents with antioxidant effect from T. domingensis fruit.Keywords: Typha domingensis, Antiglucosidase, Antioxidant, Proanthocyanidin, Hydroxycinnamic acid, Polyphenol, Coumari

Physical and antioxidative responses of Orthosiphon stamineus towards various copper and lead concentrations

Plants normally change their physiological and biochemical properties when exposed to heavy metal stress. We investigated the response of Orthosiphon stamineus towards different concentrations of Pb (0, 2, 5, 8 mg/L) and Cu (1, 2, 4, 5 mg/L). Heavy metals left in soil, plant physical characteristics, and the level of antioxidants in O. stamineus were determined. Our results showed that the tested Pb concentrations did not significantly affect stem elongation, but at 2 mg/L, Pb increased the leaf growth. Pb at 5 and 8 mg/L increased the total plant biomass. In contrast, 5 mg/L Cu treatment affected stem elongation and the root length of O. stamineus. The concentrations of Pb and Cu in soil were significantly reduced after the plants were harvested. Biochemically, 5 mg/L Pb had significantly increased the activity of catalase, while Cu at 5 mg/L significantly reduced the activity of superoxide dismutase and ascorbate peroxidase. Total flavonoid content increased in Pb-treated plants, but the total phenolics content decreased. Cu treatment at 2 mg/L, on the other hand increased the total phenolics content. Our results demonstrated that O. stamineus adapt to metal stress via physical changes, and scavenge oxygen radicals through enzymatic and non-enzymatic antioxidant productions

Antioxidant activities of methanol extract and solvent fractions of Marine macroalga, Avrainvillea erecta (Berkeley) a. Gepp and E.S. Gepp (Dichotomosiphonaceae)

Purpose: To determine the antioxidant activity of methanol extract (ME) and solvent fractions of Avrainvillea erecta as well as their total phenolic and flavonoid contents. Methods: The antioxidant activities of ME as well as its chloroform, butanol, and aqueous fractions (CF, BF and WF, respectively) of A. erecta were evaluated via 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and hydrogen peroxide (H2O2) scavenging assays as well as ferric reducing antioxidant power (FRAP) assay. Total phenolic and flavonoid contents were determined spectrophotometrically. Results: CF and BF possessed equally high DPPH scavenging activity with half-maximal effective concentration (EC50) of 535 and 532 mg/ml, respectively. CF had stronger NO scavenging activity (EC50 743 µg/mL) than ME and BF, although weaker compared with quercetin (EC50 279 µg/ml). CF also produced the highest FRAP value (451 µmol Fe2+/g) among all samples examined. Notably, H2O2 scavenging activity was only found in CF (EC50 387 µg/ml), which was as strong (p > 0.05) as that of gallic acid (EC50 456 µg/mL). BF had the highest total phenolic content while CF had the highest total flavonoid content. Conclusion: CF of A. erecta, which has the highest flavonoid content of all the extracts evaluated, is a potential source of natural antioxidants, especially hydrogen peroxide scavengers

A global review on short peptides: frontiers and perspectives

Peptides are fragments of proteins that carry out biological functions. They act as signaling entities via all domains of life and interfere with protein-protein interactions, which are indispensable in bio-processes. Short peptides include fundamental molecular information for a prelude to the symphony of life. They have aroused considerable interest due to their unique features and great promise in innovative bio-therapies. This work focusing on the current state-of-the-art short peptide-based therapeutical developments is the first global review written by researchers from all continents, as a celebration of 100 years of peptide therapeutics since the commencement of insulin therapy in the 1920s. Peptide “drugs” initially played only the role of hormone analogs to balance disorders. Nowadays, they achieve numerous biomedical tasks, can cross membranes, or reach intracellular targets. The role of peptides in bio-processes can hardly be mimicked by other chemical substances. The article is divided into independent sections, which are related to either the progress in short peptide-based theranostics or the problems posing challenge to bio-medicine. In particular, the SWOT analysis of short peptides, their relevance in therapies of diverse diseases, improvements in (bio)synthesis platforms, advanced nano-supramolecular technologies, aptamers, altered peptide ligands and in silico methodologies to overcome peptide limitations, modern smart bio-functional materials, vaccines, and drug/gene-targeted delivery systems are discussed

Enzyme-Assisted Discovery of Antioxidant Peptides from Edible Marine Invertebrates: A Review

Marine invertebrates, such as oysters, mussels, clams, scallop, jellyfishes, squids, prawns, sea cucumbers and sea squirts, are consumed as foods. These edible marine invertebrates are sources of potent bioactive peptides. The last two decades have seen a surge of interest in the discovery of antioxidant peptides from edible marine invertebrates. Enzymatic hydrolysis is an efficient strategy commonly used for releasing antioxidant peptides from food proteins. A growing number of antioxidant peptide sequences have been identified from the enzymatic hydrolysates of edible marine invertebrates. Antioxidant peptides have potential applications in food, pharmaceuticals and cosmetics. In this review, we first give a brief overview of the current state of progress of antioxidant peptide research, with special attention to marine antioxidant peptides. We then focus on 22 investigations which identified 32 antioxidant peptides from enzymatic hydrolysates of edible marine invertebrates. Strategies adopted by various research groups in the purification and identification of the antioxidant peptides will be summarized. Structural characteristic of the peptide sequences in relation to their antioxidant activities will be reviewed. Potential applications of the peptide sequences and future research prospects will also be discussed

Seafood Paramyosins as Sources of Anti-Angiotensin-Converting-Enzyme and Anti-Dipeptidyl-Peptidase Peptides after Gastrointestinal Digestion: A Cheminformatic Investigation

Paramyosins, muscle proteins occurring exclusively in invertebrates, are abundant in seafoods. The potential of seafood paramyosins (SP) as sources of anti-angiotensin-converting-enzyme (ACE) and anti-dipeptidyl-peptidase (DPP-IV) peptides is underexplored. This in silico study investigated the release of anti-ACE and anti-DPP-IV peptides from SP after gastrointestinal (GI) digestion. We focused on SP of the common octopus, Humboldt squid, Japanese abalone, Japanese scallop, Mediterranean mussel, Pacific oyster, sea cucumber, and Whiteleg shrimp. SP protein sequences were digested on BIOPEP-UWM, followed by identification of known anti-ACE and anti-DPP-IV peptides liberated. Upon screening for high-GI-absorption, non-allergenicity, and non-toxicity, shortlisted peptides were analyzed via molecular docking and dynamic to elucidate mechanisms of interactions with ACE and DPP-IV. Potential novel anti-ACE and anti-DPP-IV peptides were predicted by SwissTargetPrediction. Physicochemical and pharmacokinetics of peptides were predicted with SwissADME. GI digestion liberated 2853 fragments from SP. This comprised 26 known anti-ACE and 53 anti-DPP-IV peptides exhibiting high-GI-absorption, non-allergenicity, and non-toxicity. SwissTargetPrediction predicted three putative anti-ACE (GIL, DL, AK) and one putative anti-DPP-IV (IAL) peptides. Molecular docking found most of the anti-ACE peptides may be non-competitive inhibitors, whereas all anti-DPP-IV peptides likely competitive inhibitors. Twenty-five nanoseconds molecular dynamics simulation suggests the stability of these screened peptides, including the three predicted anti-ACE and one predicted anti-DPP-IV peptides. Seven dipeptides resembling approved oral-bioavailable peptide drugs in physicochemical and pharmacokinetic properties were revealed: AY, CF, EF, TF, TY, VF, and VY. In conclusion, our study presented in silico evidence for SP being a promising source of bioavailable and safe anti-ACE and anti-DPP-IV peptides following GI digestions

Computational Screening for the Anticancer Potential of Seed-Derived Antioxidant Peptides: A Cheminformatic Approach

Some seed-derived antioxidant peptides are known to regulate cellular modulators of ROS production, including those proposed to be promising targets of anticancer therapy. Nevertheless, research in this direction is relatively slow owing to the inevitable time-consuming nature of wet-lab experimentations. To help expedite such explorations, we performed structure-based virtual screening on seed-derived antioxidant peptides in the literature for anticancer potential. The ability of the peptides to interact with myeloperoxidase, xanthine oxidase, Keap1, and p47phox was examined. We generated a virtual library of 677 peptides based on a database and literature search. Screening for anticancer potential, non-toxicity, non-allergenicity, non-hemolyticity narrowed down the collection to five candidates. Molecular docking found LYSPH as the most promising in targeting myeloperoxidase, xanthine oxidase, and Keap1, whereas PSYLNTPLL was the best candidate to bind stably to key residues in p47phox. Stability of the four peptide-target complexes was supported by molecular dynamics simulation. LYSPH and PSYLNTPLL were predicted to have cell- and blood-brain barrier penetrating potential, although intolerant to gastrointestinal digestion. Computational alanine scanning found tyrosine residues in both peptides as crucial to stable binding to the targets. Overall, LYSPH and PSYLNTPLL are two potential anticancer peptides that deserve deeper exploration in future