Enhanced antimicrobial, antioxidant and anticancer activity of Rhizophora apiculata: An experimental report

The present study is designed to evaluate the antimicrobial, antioxidant and anticancer activities of Rhizophora apiculata. Initially, the phenolic and flavonoid content was quantified in solvent extracts, and gallic acid and rutin were used as a control, respectively. Further, antimicrobial and minimal inhibitory activities of different solvent extracts were assessed against human clinical pathogenic bacteria, and the results showed that butanol and methanol extract has potential antimicrobial activity. FTIR analysis of solvent extracts showed the presence of phenolic compounds at 3409-3430 cm^-1 that actively involved in various applications including antioxidant and anticancer activities. The in vitro antioxidant activity of solvent extracts showed excellent antioxidant potential, about 84% of DPPH free-radical scavenging, 76% of hydrogen peroxide, 82% of hydroxyl radical scavenging, and 80% of reducing power. Two-way ANOVA analysis showed that the highly significant effect of antioxidant activity depends on the concentration of extracts. The DNA protection efficiency of extracts against oxidative damage was confirmed by DNA nicking assay using bacterial DNA. The methanol extract effectively inhibited the growth and induces the apoptosis through ROS generation and sensitizes the mitochondrial membrane potential of A549 lung cancer cells. Taken together, the results showed that the solvent extracts of R. apiculata could be potential antioxidant and anticancer agents.

Radiation-induced inflammation and autoimmune diseases

Currently, ionizing radiation (IR) plays a key role in the agricultural and medical industry, while accidental exposure resulting from leakage of radioactive sources or radiological terrorism is a serious concern. Exposure to IR has various detrimental effects on normal tissues. Although an increased risk of carcinogenesis is the best-known long-term consequence of IR, evidence has shown that other diseases, particularly diseases related to inflammation, are common disorders among irradiated people. Autoimmune disorders are among the various types of immune diseases that have been investigated among exposed people. Thyroid diseases and diabetes are two autoimmune diseases potentially induced by IR. However, the precise mechanisms of IR-induced thyroid diseases and diabetes remain to be elucidated, and several studies have shown that chronic increased levels of inflammatory cytokines after exposure play a pivotal role. Thus, cytokines, including interleukin-1(IL-1), tumor necrosis factor (TNF-α) and interferon gamma (IFN-γ), play a key role in chronic oxidative damage following exposure to IR. Additionally, these cytokines change the secretion of insulin and thyroid-stimulating hormone(TSH). It is likely that the management of inflammation and oxidative damage is one of the best strategies for the amelioration of these diseases after a radiological or nuclear disaster. In the present study, we reviewed the evidence of radiation-induced diabetes and thyroid diseases, as well as the potential roles of inflammatory responses. In addition, we proposed that the mitigation of inflammatory and oxidative damage markers after exposure to IR may reduce the incidence of these diseases among individuals exposed to radiation.

Drosophila Ubiquitin C-Terminal Hydrolase Knockdown Model of Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder worldwide. Many factors have been shown to contribute to its pathogenesis including genetic and environmental factors. Ubiquitin C-terminal hydrolase L1 (UCHL1) is also known to be involved in the pathogenesis of PD. We herein modeled the study of UCHL1 in Drosophila melanogaster and investigated its functions in PD. The specific knockdown of the Drosophila ortholog of UCHL1 (dUCH) in dopaminergic neurons (DA neurons) led to the underdevelopment and/or degeneration of these neurons, specifically in DL1 DA neuron cluster in the larval brain lobe and PPM2, PPM3, PPL2ab, and VUM DA neuron clusters in the adult brain. These defects were followed by a shortage of dopamine in the brain, which subsequently resulted in locomotor dysfunction. The degeneration of DA neurons in dUCH knockdown adult brain, which occurred progressively and severely during the course of aging, mimics the epidemiology of PD. DA neuron and locomotor defects were rescued when dUCH knockdown flies were treated with vitamin C, a well-known antioxidant. These results suggest that dUCH knockdown fly is a promising model for studying the pathogenesis and epidemiology of PD as well as the screening of potential antioxidants for PD therapeutics.

Proanthocyanidins against Oxidative Stress: From Molecular Mechanisms to Clinical Applications

Proanthocyanidins (PCs) are naturally occurring polyphenolic compounds abundant in many vegetables, plant skins (rind/bark), seeds, flowers, fruits, and nuts. Numerous in vitro and in vivo studies have demonstrated myriad effects potentially beneficial to human health, such as antioxidation, anti-inflammation, immunomodulation, DNA repair, and antitumor activity. Accumulation of prooxidants such as reactive oxygen species (ROS) exceeding cellular antioxidant capacity results in oxidative stress (OS), which can damage macromolecules (DNA, lipids, and proteins), organelles (membranes and mitochondria), and whole tissues. OS is implicated in the pathogenesis and exacerbation of many cardiovascular, neurodegenerative, dermatological, and metabolic diseases, both through direct molecular damage and secondary activation of stress-associated signaling pathways. PCs are promising natural agents to safely prevent acute damage and control chronic diseases at relatively low cost. In this review, we summarize the molecules and signaling pathways involved in OS and the corresponding therapeutic mechanisms of PCs.

Assessment of fipronil toxicity on wistar rats: A hepatotoxic perspective

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Fipronil was found to induce oxidative stress.

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Exposure to fipronil resulted in histopathology of hepatic tissue.

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Peak absorption changes in FT-IR was evident in liver of rats on Fipronil exposure.

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Fipronil modulated the enzymatic threshold of hepatic enzymes.

Extensive pesticide application has contributed to environmental contamination globally, imposing adverse health effects on non-target organisms. Need for an understanding of cellular response following pesticide exposure is, therefore, paradigmatic for elucidating perturbations occurring within biological systems. The present investigation was aimed to examine safe and toxic dose level of a persistent, synthetic, phenylpyrazole based insecticide, Fipronil (FPN) on rat liver. Experimental animals were divided into four groups and gavaged with 0.0 (control), 32.33 (high), 12.12 (medium) and 6.46 mg/kg body weight/day (low dose) of FPN for 90 days. While results for liver catalase and glutathione S-transferase indicated significant changes in high and medium dose groups, the superoxide dismutase and glutathione peroxidase activity suggested significant changes in all exposed groups as compared to control. Elevated levels of liver malondialdehyde reflected oxidative damage potential under the exposed groups but remained insignificant for low dose. Histologically, structural irregularities with findings like impaired portal vein and hypertrophy of hepatocytes were prominent under all the exposed groups. The FT-IR based spectral investigation further revealed changes in absorption patterns and peak intensities in rats exposed to FPN. Significant elevation was also noticed in liver enzymes; alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase in rat serum suggesting the toxicity in dose -dependent pattern. Based on the outcome, it could be ascertained that the toxicity of FPN is certain at high and medium dose levels but remains ambiguous at a low dose of 6.46 mg/kg body weight/day. The current upshots serve as a preliminary report thereby advising the farming community against the usage of FPN insecticide.

Fabrication of g-C3N4/NiO heterostructured nanocomposite modified glassy carbon electrode for quercetin biosensor

Herein, we report a one-pot synthesis of structurally uniform and electrochemically active graphitic carbon nitride/nickel oxide (g-C₃N₄/NiO) nanocomposite and an investigation on the electrocatalytic oxidation of quercetin (QR). The synthesized g-C₃N₄/NiO nanocomposite has uniform surface distribution, which was characterized with scanning electron microscopy (SEM). Moreover, the composition of synthesized g-C₃N₄/NiO nanocomposite was characterized by UV-vis-spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR spectra), BET, SEM and HRTEM. The g-C₃N₄/NiO was electrochemically treated in 0.1 MPBS solution through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The peak current response increases linearly with QR concentration from 0.010 μM to 250 µM with a fast response time of less than 2 s and a detection limit of 0.002 μM. To further evaluate the feasibility of using this sensor for real sample analysis, QR content in various real samples including green tea, green apple, honey suckle were determined and satisfactory results were achieved.

Maintenance of genome stability: the unifying role of interconnections between the DNA damage response and RNA-processing pathways

Endogenous and exogenous factors can severely affect the integrity of genetic information by inducing DNA damage and impairing genome stability. The protection of genome integrity is ensured by the so-called "DNA damage response" (DDR), a set of evolutionary-conserved events that, triggered upon DNA damage detection, arrests the cell cycle, and attempts DNA repair. Here, we review the role of the DDR proteins as post-transcriptional regulators of gene expression, in addition to their roles in DNA damage recognition, signaling, and repair. At the same time, we discuss recent insights into how pre-mRNA splicing factors go beyond their splicing activities and play direct functions in detecting, signaling, and repairing DNA damage. The importance of extensive two-way crosstalk and interaction between the RNA processing and the DDR stems from growing evidence that the defects of their communication lead to genomic instability.

Chain-breaking antioxidant activity of hydroxylated and methoxylated magnolol derivatives: the role of H-bonds

Chemical modification of magnolol, an uncommon dimeric neolignan contained in Magnolia genus trees, provides a unique array of polyphenols having interesting biological activity potentially related to radical scavenging. The chain-breaking antioxidant activity of four new hydroxylated and methoxylated magnolol derivatives was explored by experimental and computational methods. The measurement of the rate constant of the reaction with ROO˙ radicals (k_inh) in an apolar solvent showed that the introduction of hydroxyl groups ortho to the phenolic OH in magnolol increased the k_inh value, being 2.4 × 10⁵ M^-1 s^-1 and 3.3 × 10⁵ M^-1 s^-1 for the mono and the dihydroxy derivatives respectively (k_inh of magnolol is 6.1 × 10⁴ M^-1 s^-1). The di-methoxylated derivative is less reactive than magnolol (k_inh = 1.1 × 10⁴ M^-1 s^-1), while the insertion of both hydroxyl and methoxyl groups showed no effect (6.0 × 10⁴ M^-1 s^-1). Infrared spectroscopy and theoretical calculations allowed a rationalization of these results and pointed out the crucial role of intramolecular H-bonds. We also show that a correct estimation of the rate constant of the reaction with ROO˙ radicals, by using BDE(OH) calculations, requires that the geometry of the radical is as close as possible to that of the parent phenol.

A catalyst-free intermolecular trans-iodoalkylation of alkynes

We report the first catalyst-free and trans-selective iodoalkylation reaction of alkynes with a series of α-carbonyl compounds. This unprecedented three-component iodoalkylation reaction is enabled by using (iodoethynyl)trimethylsilane as a radical initiator and iodide source. The 1,2-difunctionalization affords alkenyl iodides, which are versatile building blocks for the construction of tri-substituted alkene derivatives.

An Instrument-free Detection of Antioxidant Activity Using Paper-based Analytical Devices Coated with Nanoceria

This work reports a portable distance-based detection paper device that has a thermometer-like shape for rapid, instrument-free determination of antioxidant activity using a nanoceria assay. The assay is based on partial reduction of cerium ion from Ce⁴⁺ to Ce³⁺ on nanoceria deposited along the detection channel by antioxidants present in food, giving highly reactive oxidation products. Either these products or the parent antioxidant compounds could then bind to the OH-rich ceria nanoparticles and generate charge transfer ceria-antioxidant complexes resulting in a yellow to brown color change. The distance of the brown color on the detection channel is directly proportional to antioxidant activity, and can be easily measured using an integrated ruler without the need of any external sophisticated instrument for detection. The paper sensor has been studied for the analysis of common antioxidants and its performance was validated against traditional antioxidant assays for 11 tea sample analyses. Using the Spearman rank correlation coefficient method, the antioxidant activity of tea samples obtained from the paper device correlated with the traditional assay at the 95% confidence level. The developed sensor provided a high recovery and tolerance limit and was stable for 50 days both when stored at ambient and low temperature (6 and -20°C). The results demonstrated that the developed paper device is an alternative to allow for fast, simple, instrument-free, cheap, portable and high-throughput screening of antioxidant activity analysis in real samples.

Curcumin and derivatives function through protein phosphatase 2A and presenilin orthologues in Dictyostelium discoideum

Natural compounds often have complex molecular structures and unknown molecular targets. These characteristics make them difficult to analyse using a classical pharmacological approach. Curcumin, the main curcuminoid of turmeric, is a complex molecule possessing wide-ranging biological activities, cellular mechanisms and roles in potential therapeutic treatment, including Alzheimer's disease and cancer. Here, we investigate the physiological effects and molecular targets of curcumin in Dictyostelium discoideum. We show that curcumin exerts acute effects on cell behaviour, reduces cell growth and slows multicellular development. We employed a range of structurally related compounds to show the distinct role of different structural groups in curcumin's effects on cell behaviour, growth and development, highlighting active moieties in cell function, and showing that these cellular effects are unrelated to the well-known antioxidant activity of curcumin. Molecular mechanisms underlying the effect of curcumin and one synthetic analogue (EF24) were then investigated to identify a curcumin-resistant mutant lacking the protein phosphatase 2A regulatory subunit (PsrA) and an EF24-resistant mutant lacking the presenilin 1 orthologue (PsenB). Using in silico docking analysis, we then showed that curcumin might function through direct binding to a key regulatory region of PsrA. These findings reveal novel cellular and molecular mechanisms for the function of curcumin and related compounds.

Summary: To unlock the therapeutic potential of curcumin and related compounds, we employ a tractable model system to characterise their cellular and molecular effects and propose novel targets implicated in disease.

Hypochlorous Acid Promoted Platinum Drug Chemotherapy by Myeloperoxidase-Encapsulated Therapeutic Metal Phenolic Nanoparticles

This study applies in situ production of hypochlorous acid (HOCl) to improve the therapeutic efficacy of platinum drugs. The phagocytic enzyme myeloperoxidase (MPO) is coated with two functional polyphenol derivatives (platinum prodrug polyphenols and PEG polyphenols) and ferric ion by metal phenolic coordination, which can shield MPO from degradation by other compounds in the blood. Moreover, the platinum prodrug can be reduced to cisplatin in cells and produce hydrogen peroxide (H₂O₂). The MPO catalyzes the conversion of H₂O₂ to HOCl in the intercellular environment. The as-prepared MPO Pt PEG nanoparticles (MPP NPs) can be employed as a reactive oxygen species cascade bioreaction to enhance platinum drug therapy. The MPP NPs show prolonged blood circulation and high tumor accumulation as evidenced by ⁸⁹Zr-based positron emission tomography imaging. The MPP NPs effectively inhibit tumor growth in vivo. As a first-in-class platform to harness the highly toxic HOCl in nanomedicine for cancer therapy, this strategy may open doors for further development of progressive therapeutic systems.

Photoelectron spectra and biological activity of cinnamic acid derivatives revisited

The electronic structures of several derivatives of cinnamic acid have been studied by UV photoelectron spectroscopy (UPS) and Green's function quantum chemical calculations. The spectra reveal the presence of dimers in the gas phase for p-coumaric and ferulic acids. The electronic structure analysis has been related to the biological properties of these compounds through the analysis of some structure-activity relationships (SAR).

Pre-treatment of extracellular water soluble pigmented secondary metabolites of marine imperfect fungus protects HDF cells from UVB induced oxidative stress

The melanin precursor of fungal origin was found to be an excellent UVB inhibiting agent as experimented in HDF cells and in small animals.

A smart multi-functional coating based on anti-pathogen micelles tethered with copper nanoparticlesviaa biosynthesis method usingl-vitamin C

A multi-functional anti-pathogen coating with “release-killing”, “contact-killing” and “anti-adhesion” properties was prepared from biocompatible polymer encapsulated chlorine dioxide (ClO₂) which protected the active ingredient from the outside environment.

Experimental study of the protective effect of mesosilica-supported 5-hydroxymethylfurfural on UV-induced aging of human dermal fibroblasts

The drug 5-HMF (5-hydroxymethylfurfural, C₆H₆O₃) is extensively studied for its antioxidative and anti-inflammatory properties. However, its unstable properties and biotoxicity restrict its use in skin care products and therapy. The present study was aimed at evaluating the potential of three-dimensional dendritic mesoporous silica nanospheres (3D-dendritic MSNs) as a topical carrier system for 5-HMF delivery. The encapsulation of the carrier also enhances the stability of the drug. Based on the results of Brunauer–Emmet–Teller (BET) analysis, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and UV-vis diffuse reflectance spectroscopy, drug delivery systems were successfully fabricated and the loading capacity (LC%) and entrapment efficiency (EE%) were also assessed. In vitro cell tests revealed the outstanding biocompatibility and inoxidizability of 3D-dendritic MSNs. There is no effect on the antioxidant properties of the drug. Therefore, mesoporous silica can be combined with 5-HMF and used as potential antioxidant medicine in cosmetic applications.

The drug 5-HMF (5-hydroxymethylfurfural, C₆H₆O₃) is extensively studied for its antioxidative and anti-inflammatory properties.

Angiotensin-1-converting enzyme inhibition, antioxidant activity, and modulation of cerebral Na+/K+ ATPase by free phenolics of African locust bean (Parkia biglobosa)

AIMS

To investigate the antioxidant activities and effects of free phenols (FPPB) and bound phenols (BPPB) of Parkia biglobosa leaves on some enzymes of neuro-cardiovascular relevance.

METHODS AND RESULTS

HPLC-DAD fingerprinting of FPPB and BPPB, and the antihemolytic, radical (1,1-diphenyl-2 picrylhydrazyl, DPPH; 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid), ABTS) scavenging and ferric reducing antioxidant properties of extracts, were assessed. In addition, the effects of the phenolics on angiotensin-1-converting enzyme (ACE), cerebral acetylcholinesterase/butyrylcholinesterase (AChE/BuChE), and Na+/K+ATPase were determined in vitro. FPPB was more potent than BPPB in terms of ABTS (EC50:4.06 ± 0.3 vs 24.07 ± 2.1 μg/mL) and DPPH (EC50:3.82 ± 0.2 vs 10.22 ± 0.1 μg/mL) radicals scavenged, respectively. The free phenolic extract was a better DPPH. scavenger than ascorbic acid (EC50 = 12.58 ± 0.4 μg/mL; DPPH reference) and compared well with Trolox (EC50:4.44 ± 0.08 μg/mL; ABTS reference). The anti-hemolytic effect of FPPB (36%) and BPPB (53%) was highest at 15 μg/mL but lower than that recorded for ascorbic acid (67% at 10 μg/mL). Even though FPPB (IC50 = 15.35 ± 4.0 μg/mL) and BPPB (IC50 = 46.85 ± 3.3 μg/mL) showed considerably lower ACE-inhibitory effect than ramipril (IC50:0.173 ± 0.04 μg/mL), both extracts demonstrated dose-dependent, significant (p < 0.01/p < 0.05) inhibition of the enzyme. FPPB increased cerebral Na+/K+ATPase activity but neither phenolic extract affects cerebral AChE/BuChE activities. HPLC-DAD revealed catechin, caffeic acid, and quercetin, respectively, as the major phenolics (mg/g) in FPPB (29.85, 30.29, and 17.10) and BPPB (32.70, 30.51, and 19.25).

CONCLUSION

The effects of P biglobosa on ACE and cerebral ATPase are related to its constituent phenolics. ACE inhibition could be an important mechanism underlying the documented hypotensive effect of the plant.

Interactions of flavonoids with α-amylase and starch slowing down its digestion

Hydrophobic flavonoids can suppress starch digestion in the intestine by forming starch-flavonoid complexes.

Acacia hydaspica R. Parker prevents doxorubicin-induced cardiac injury by attenuation of oxidative stress and structural Cardiomyocyte alterations in rats

BACKGROUND

The use of doxorubicin (DOX) an anthracycline antineoplastic agent is withdrawn due to its cardio-toxic side effects. Oxidative stress has been recognized as the primary cause of DOX induced cardiotoxicity. We have investigated whether polyphenol rich ethyl acetate extract of Acacia hydaspica (AHE) can attenuate doxorubicin-induced cardiotoxicity via inhibition of oxidative stress.

METHODS

AHE was administered orally to rats once daily for 6 weeks at doses of 200 and 400 mg/kg b.w. DOX (3 mg/kg b.w. i.p., single dose/week) was administered for 6 weeks (chronic model). The parameters studied to evaluate cardioprotective potential were the serum cardiac function biomarkers (CK, CKMB, AST and LDH), hematological parameters, cardiac tissue antioxidant enzymatic status and oxidative stress markers, and histopathological analysis to validate biochemical findings.

RESULTS

Chronic 6 week treatment of DOX significantly deteriorated cardiac function biomarkers and decreased the activities of antioxidant enzymes, whereas significant increase in oxidative stress biomarkers was noticed in comparison to control group. AHE dose dependently protected DOX-induced leakage of cardiac enzymes in serum and ameliorated DOX-induced oxidative stress; as evidenced by decreasing lipid peroxidation, H₂O₂ and NO content with increase in phase I and phase II antioxidant enzymes. Doxorubicin treatment produced severe morphological lesions, leucopenia, decrease in red blood cell counts and hemoglobin concentrations. AHE co-treatment protected the heart and blood elements from the toxic effects of doxorubicin as indicated by the recovery of hematological parameters to normal values and prevention of myocardial injuries in a dose dependent way. The protective potency of AHE (400 mg/kg b.w) was equivalent to silymarin.

CONCLUSION

Results revealed that AHE showed protective effects against DOX induce cardiotoxicity. The protective effect might attribute to its polyphenolic constituents and antioxidant properties. AHE might be helpful in combination therapies as safer and efficient.

Oxidative stress, consequences and ROS mediated cellular signaling in rheumatoid arthritis

There are numerous extra- and intra-cellular processes involved in the production of reactive oxygen species (ROS). Augmented ROS generation can cause the damage of biomolecules such as proteins, nucleic acid and lipids. ROS act as an intracellular signaling component and is associated with various inflammatory responses, chronic arthropathies, including rheumatoid arthritis (RA). It is well documented that ROS can activate different signaling pathways having a vital importance in the patho-physiology of RA. Hence, understanding of the molecular pathways and their interaction might be advantageous in the development of novel therapeutic approaches for RA.

Rice Bran Metabolome Contains Amino Acids, Vitamins & Cofactors, and Phytochemicals with Medicinal and Nutritional Properties

BACKGROUND

Rice bran is a functional food that has shown protection against major chronic diseases (e.g. obesity, diabetes, cardiovascular disease and cancer) in animals and humans, and these health effects have been associated with the presence of bioactive phytochemicals. Food metabolomics uses multiple chromatography and mass spectrometry platforms to detect and identify a diverse range of small molecules with high sensitivity and precision, and has not been completed for rice bran.

RESULTS

This study utilized global, non-targeted metabolomics to identify small molecules in rice bran, and conducted a comprehensive search of peer-reviewed literature to determine bioactive compounds. Three U.S. rice varieties (Calrose, Dixiebelle, and Neptune), that have been used for human dietary intervention trials, were assessed herein for bioactive compounds that have disease control and prevention properties. The profiling of rice bran by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) identified 453 distinct phytochemicals, 209 of which were classified as amino acids, cofactors & vitamins, and secondary metabolites, and were further assessed for bioactivity. A scientific literature search revealed 65 compounds with health properties, 16 of which had not been previously identified in rice bran. This suite of amino acids, cofactors & vitamins, and secondary metabolites comprised 46% of the identified rice bran metabolome, which substantially enhanced our knowledge of health-promoting rice bran compounds provided during dietary supplementation.

CONCLUSION

Rice bran metabolite profiling revealed a suite of biochemical molecules that can be further investigated and exploited for multiple nutritional therapies and medical food applications. These bioactive compounds may also be biomarkers of dietary rice bran intake. The medicinal compounds associated with rice bran can function as a network across metabolic pathways and this metabolite network may occur via additive and synergistic effects between compounds in the food matrix.

Graphene oxide induces cytotoxicity and oxidative stress in bluegill sunfish cells

Graphene oxide (GO) is considered a promising material for biological application due to its unique properties. However, the potential toxicity of GO to aquatic organism particularly bluegill sun fish cells (BF-2) is unexplored or remains poorly understood. GO-induced cytotoxicity and oxidative stress in BF-2 cells were assessed using a battery of biomarkers. Two different biological assays (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and neutral red uptake were used to evaluate the cytotoxicity of GO on BF-2 cells. It was found that GO induced dose- and time-dependent cytotoxicity on BF-2 cells. BF-2 cells exposed to lower concentration of GO (40 μg ml^-1 ) for 24 induced morphological changes when compared to their respective controls. As evidence for oxidative stress lipid peroxidation, superoxide dismutase, catalase, reactive oxygen species and 8-hydroxy-2'-deoxyguanosine levels were increased and glutathione levels were found to decline in BF-2 cells after treatment with GO. Our findings demonstrate that GO when exposed to BF-2 fish cells cause oxidative stress.

Chitosan-based nano-formulation enhances the anticancer efficacy of hesperetin

Cancer is one of the major causes of increased morbidity and mortality in modern society. Colorectal cancer is the third leading cause for cancer related death worldwide. Current chemotherapeutics are not very effective and have severe side effects. Hesperetin is a bioflavonoid from citrus fruits and its clinical use is restricted because of the poor water solubility. Folate receptor is overexpressed in various cancer cells. Therefore, we synthesized the chitosan folate hesperetin nanoparticle (CFH) by covalently conjugating folic acid with chitosan molecules. The size of the CFH nanoparticles is around 450nm, which is advantageous for passively targeting the cancer cell specifically due to the leaky vasculature of the tumour. Particle surface and size were observed using SEM and TEM studies. The results show that hesperetin has an IC50 value of 190μM and it induces apoptosis in HCT15 cells, however, CFH is very potent in inhibiting the proliferation with the IC50 value of 28μM. In addition, CFH inhibited colony formation and induced apoptosis by regulating the expression of proapoptotic genes expression. Therefore, the chitosan - folic acid conjugation appears to be the suitable carrier for colorectal cancer cell-specific delivery of hesperetin.

Response Surface Optimisation for the Production of Antioxidant Hydrolysates from Stone Fish Protein Using Bromelain

Protein hydrolysates produced from different food sources exhibit therapeutic potential and can be used in the management of chronic diseases. This study was targeted to optimise the conditions for the hydrolysis of stone fish protein to produce antioxidant hydrolysates using central composite design (CCD) by response surface methodology (RSM). The stone fish protein was hydrolysed under the optimum predicted conditions defined by pH (6.5), temperature (54°C), E/S ratio (1.5%), and hydrolysis time (360 min). The hydrolysates were then evaluated for 2,2-diphenyl-1-picrylhydrazyl radical (DPPH^•) scavenging activity and ferrous ion- (Fe²⁺-) chelating activity. Results validation showed no significant difference between the experimental values of DPPH^• scavenging activity (48.94%) and Fe²⁺-chelating activity (25.12%) obtained at 54.62% degree of hydrolysis (DH) compared to their corresponding predicted values of 49.79% and 24.08% at 53.08% DH, respectively. The hydrolysates demonstrated non-Newtonian behavior (n < 1) with stronger shear-thinning effect and higher viscosities at increasing concentration. Thus, RSM can be considered as a promising strategy to optimise the production of stone fish protein hydrolysates containing antioxidant peptides. It is hoped that this finding will enhance the potential of stone fish protein hydrolysates (SHs) as therapeutic bioactive ingredient in functional foods development.

Metabolomics Reveals Cu(OH)2 Nanopesticide-Activated Anti-oxidative Pathways and Decreased Beneficial Antioxidants in Spinach Leaves

While the use of nanopesticides in modern agriculture continues to increase, their effects on crop plants are still poorly understood. Here, 4 week old spinach plants grown in an artificial medium were exposed via foliar spray to Cu(OH)₂ nanopesticide (0.18 and 18 mg/plant) or Cu ions (0.15 and 15 mg/plant) for 7 days. A gas chromatography-time-of-flight-mass spectrometry metabolomics approach was applied to assess metabolic alterations induced by Cu(OH)₂ nanopesticide in spinach leaves. Exposure to Cu(OH)₂ nanopesticide and copper ions induced alterations in the metabolite profiles of spinach leaves. Compared to the control, exposure to 18 mg of Cu(OH)₂ nanopesticide induced significant reduction (29-85%) in antioxidant or defense-associated metabolites including ascorbic acid, α-tocopherol, threonic acid, β-sitosterol, 4-hydroxybutyric acid, ferulic acid, and total phenolics. The metabolic pathway for ascorbate and aldarate was disturbed in all exposed spinach plants (nanopesticide and Cu²⁺). Cu²⁺ is responsible for the reduction in antioxidants and perturbation of the ascorbate and aldarate metabolism. However, nitrogen metabolism perturbation was nanopesticide-specific. Spinach biomass and photosynthetic pigments were not altered, indicating that metabolomics can be a rapid and sensitive tool for the detection og earlier nanopesticide effects. Consumption of antioxidants during the antioxidant defense process resulted in reduction of the nutritional value of exposed spinach.

Deep Eutectic Solvents as Convenient Media for Synthesis of Novel Coumarinyl Schiff Bases and Their QSAR Studies

Deep eutectic solvents, as green and environmentally friendly media, were utilized in the synthesis of novel coumarinyl Schiff bases. Novel derivatives were synthesized from 2-((4-methyl-2-oxo-2H-chromen-7-yl)oxy)acetohydrazide and corresponding aldehyde in choline chloride:malonic acid (1:1) based deep eutectic solvent. In these reactions, deep eutectic solvent acted as a solvent and catalyst as well. Novel Schiff bases were synthesized in high yields (65–75%) with no need for further purification, and their structures were confirmed by mass spectra, ¹H and ¹³C NMR. Furthermore, their antioxidant activity was determined and compared to antioxidant activity of previously synthesized derivatives, thus investigating their structure–activity relationship utilizing quantitative structure-activity relationship QSAR studies. Calculation of molecular descriptors has been performed by DRAGON software. The best QSAR model (R_tr = 0.636; R_ext = 0.709) obtained with three descriptors (MATS3m, Mor22u, Hy) implies that the pairs of atoms higher mass at the path length 3, three-dimensional arrangement of atoms at scattering parameter s = 21 Å⁻¹, and higher number of hydrophilic groups (-OH, -NH) enhanced antioxidant activity. Electrostatic potential surface of the most active compounds showed possible regions for donation of electrons to 1,1-diphenyl-2-picryhydrazyl (DPPH) radicals.