Simultaneous optimization of extraction and antioxidant activity from Blumea laciniata and the protective effect on Hela cells against oxidative damage

Blumea was the resource for medicine such as l-borneol showing a great economic value. Interestingly, Blumea laciniata was widely used as a folk medicine in south of China and Asia. But the chemical compounds and specific pharmacological activity were rarely reported. Therefore, in this present work, the chemical components from B. laciniata were determined and the antioxidant ability on scavenging radicals and the protection on Hela cells against H₂O₂ were evaluated. The results showed the antioxidant ability was associated with the presence of polyphenols via response surface method. Additionally, chlorogenic acid, isoorientin, rutin, luteolin-4′-O-glucoside and cinnamic acid were firstly identified in B. laciniata. Moreover, the extract from B. laciniata (EBL) showed a strong antioxidant on clearing DPPH and ABTS free radicals with a lower EC₅₀. Besides, EBL showed no toxicity on Hela cells and even could protect cells from H₂O₂ induced damage by sharply reducing the excessive reactive oxygen species, improving the mitochondrial membrane potential and then decreasing the generation of cell apoptosis. These outcomes could provide a promising understanding on the potential antioxidant.     

Cellular Antioxidant Properties of Ischnoderma Resinosum Polysaccharide

A predominant polysaccharide isolated from Ischnoderma resinosum underwent evaluation for its capacity to scavenge free radicals and its potential antioxidant properties at a cellular-oriented level. This proved that Ischnoderma resinosum polysaccharide (IRP) remarkably curtailed AAPH-induced erythrocyte hemolysis through the inhibition of the generation of ROS (p < 0.05). Rather, it caused the restoration of intracellular antioxidant enzyme (SOD, GSH-Px, and CAT) activities at an acceptable pace and the silencing of intracellular MDA formation, as well as the rescaling of LDH leakage. Furthermore, a model of oxidative stress in HepG2 cells was established by adopting 400 μM of hydrogen peroxide, which suggested that IRP manifests promising antioxidant activity. Notably, after the intervention of IRP in the H₂O₂-induced HepG2 cells, there was a statistical elevation in cell survivability (p < 0.05). IRP diminished the morphological alterations in the nucleus and decreased the secretion of ROS (p < 0.05), with a dose-dependent abrogation of apoptosis (p < 0.05). Consequently, IRP, which was isolated and purified, was able to scavenge free radicals and possessed favorable antioxidant activity that could dampen the occurrence of oxidative stimulation and effectively alleviate the AAPH-induced erythrocyte hemolysis and H₂O₂-induced oxidative damage in HepG2 cells. This provides a basis and theoretical reference for the development and utilization of IRP as a natural antioxidant, with emphasis on the exploitation of environmentally friendly and cost-effective antioxidants.     

Cytoprotective effect of selenium polysaccharide from Pleurotus ostreatus against H2O2-induced oxidative stress and apoptosis in PC12 cells

One main fraction of Selenium-enriched Pleurotus ostreatus (P. ostreatus) polysaccharide (Se-POP-1) was extracted and purified by DEAE-52 and sephadex G-100. Se-POP-1 was an approximate homogenous polysaccharide with an average molecular weight of 1.62 × 10⁴ Da, and mainly composed of glucose, mannose and galactose, with molar ratio of 5.30:1.55:2.14. The absorption peaks at 941 cm^?1 and 1048 cm^?1 in FT-IR analysis were ascribed as C-O-Se and Se=O bonds. Pr-treatment of Se-POP-1 (400 μg/mL) increased the cell survival of H₂O₂-stimulated PC12 cells and inhibited intrinsic apoptosis and oxidative stress in H₂O₂-stimulated PC12 cells via limiting DNA degradation and decreasing the reactive oxygen species (ROS) generation. In addition, up-regulation of anti-apoptotic protein Bcl-2, down- regulation of pro-apoptotic protein Bax, cleaved caspase 3, and cytochrome c were also observed. Se-POP-1 presented an obvious effect to alleviate oxidative damage and apoptosis in PC12 cells induced by H₂O₂. Therefore, Se-POP-1 possessed potent antioxidant and biological activities with the ability to prevent oxidation via scavenging ROS and free radicals in cells. It could be developed as organic selenium dietary supplement and functional food.     

Chemical Composition,Antioxidant and Cytoprotective Potentials of Carica papaya Leaf Extracts: A Comparison of Supercritical Fluid and Conventional Extraction Methods

The leaves of Carica papaya (CP) are rich in natural antioxidants. Carica papaya has traditionally been used to treat various ailments, including skin diseases. This study aims to decipher the antioxidant effects and phytochemical content of different CP leaf extracts (CPEs) obtained using supercritical carbon dioxide (scCO₂) and conventional extraction methods. The antioxidant activities of CPEs were evaluated by cell-free (1,1-diphenyl-2-picryl-hydrazyl (DPPH) and ferric-reduced antioxidative power (FRAP)) and cell-based (H₂O₂) assay. Both C. papaya leaf scCO₂ extract with 5% ethanol (CPSCE) and C. papaya leaf scCO₂ extract (CPSC) exhibited stronger DPPH radical scavenging activity than conventional extracts. In the FRAP assay, two hydrophilic extracts (C. papaya leaf ethanol extract (CPEE) and C. papaya freeze-dried leaf juice (CPFD)) showed relatively stronger reducing power compared to lipophilic extracts. Cell-based assays showed that CPFD significantly protected skin fibroblasts from H₂O₂-induced oxidative stress in both pre-and post-treatment. CPEE protected skin fibroblasts from oxidative stress in a dose-dependent manner while CPSCE significantly triggered the fibroblast recovery after treatment with H₂O₂. GC-MS analysis indicated that CPSCE had the highest α-tocopherol and squalene contents. By contrast, both CP hydrophilic extracts (CPEE and CPFD) had a higher total phenolic content (TPC) and rutin content than the lipophilic extracts. Overall, CPEs extracted using green and conventional extraction methods showed antioxidative potential in both cell-based and cell-free assays due to their lipophilic and hydrophilic antioxidants, respectively.     

Interaction between hydrogen peroxide and cobalt(II) acetylacetonate in the system of reverse micelles of triton X-100 nonionic surfactant in cyclohexane

The yield of free radicals upon the decomposition of hydrogen peroxide catalyzed by cobalt acetylacetonate (Co(acac)₂) in the systems of reverse micelles of TX-100/n-hexanol and AOT in cyclohexane at 37°C was studied with the inhibitor method using a stable nitroxyl radical as a spin trap. It is shown that, in micellar AOT solutions in cyclohexane as well as in n-decane, H₂O₂ and Co(acac)₂ in practice do not react, because H₂O₂ is localized in a micelle water pool and Co(acac)₂, in the organic phase. Therefore, the generation of radicals is not observed in AOT solutions in cyclohexane, whereas, in aqueous solution, Co(acac)₂ catalyzes the radical decomposition of H₂O₂. In the system of mixed reverse micelles of TX-100 and n-hexanol in cyclohexane, at equal overall concentrations of H₂O₂ and Co(acac)₂, the rate of radical formation is much higher than in aqueous solution; i.e., the micellar catalysis of the radical decomposition of H₂O₂ takes place. It follows from measurements of UV and ESR spectra and the kinetics of changes in the content of peroxides in the reaction mixture that TX-100 and n-hexanol react with free radicals formed upon H₂O₂ decomposition and with atmospheric oxygen.     

Antioxidant Activity of Acanthopanax senticosus Flavonoids in H2O2-Induced RAW 264.7 Cells and DSS-Induced Colitis in Mice

The redox reaction is a normal process of biological metabolism in the body that leads to the production of free radicals. Under conditions such as pathogenic infection, stress, and drug exposure, free radicals can exceed normal levels, causing protein denaturation, DNA damage, and the oxidation of the cell membrane, which, in turn, causes inflammation. Acanthopanax senticosus (A. senticosus) flavonoids are the main bioactive ingredients with antioxidant function. H₂O₂-treated RAW 264.7 cells and DSS-induced colitis in mice were used to evaluate the antioxidant properties of A. senticosus flavonoids. The results show that A. senticosus flavonoids can significantly downregulate the levels of ROS and MDA in H₂O₂-treated RAW 264.7 cells and increase the levels of CAT, SOD, and GPx. A. senticosus flavonoids can also increase the body weights of DSS-induced colitis mice, increase the DAI index, and ameliorate the shortening of the colon. ELISA experiments confirmed that A. senticosus flavonoids could reduce the level of MDA in the mouse serum and increase the levels of SOD, CAT, and GPx. Histopathology showed that the tissue pathological changes in the A. senticosus flavonoid group were significantly lower than those in the DSS group. The Western blot experiments showed that the antioxidant capacity of A. senticosus flavonoids was accomplished through the Nrf2 pathway. In conclusion, A. senticosus flavonoids can relieve oxidative stress in vivo and in vitro and protect cells or tissues from oxidative damage.     

Evaluation of the antioxidant and antibacterial properties of various solvents extracts of Annona squamosa L. leaves

The present work was conducted aiming to evaluate the effect of different solvent extracts on the antioxidant and antibacterial activities of Annona squamosa L. leaves. Four solvents were chosen for the study namely; methanol 80%, acetone 50%, ethanol 50% and boiling water. Acetone and boiling water gave the highest extraction yields as compared to methanol and ethanol. Total phenolic contents of the four extracts were significantly different with acetone being the most efficient solvent and water being the least efficient one. Correlation coefficient between the total antioxidant and total phenolic content was found to be R² = 0.89 suggesting the contribution of phenolic compounds of the extract by 89% to its total antioxidant activity. The extracts were capable of scavenging H₂O₂ in a range of 43–54%. Reducing power of the extracts increased by increasing their concentration. The extracts were found to exert low to moderate antibacterial activity compared to a standard antibacterial agent. The bacterial inhibition of the extracts was found to positively correlate with their phenolic contents.     

Protective Effect of Resveratrol on Immortalized Duck Intestinal Epithelial Cells Exposed to H2O2

Resveratrol is a polyphenolic compound with anti-oxidation effects. The mechanisms underlying the antioxidant effects of resveratrol in duck intestinal epithelial cells remain unclear. The protective effects of resveratrol against oxidative stress induced by H₂O₂ on immortalized duck intestinal epithelial cells (IDECs) were investigated. IDECs were established by transferring the lentivirus-mediated simian virus 40 large T (SV40T) gene into small intestinal epithelial cells derived from duck embryos. IDECs were morphologically indistinguishable from the primary intestinal epithelial cells. The marker protein cytokeratin 18 (CK18) was also detected in the cultured cells. We found that resveratrol significantly increased the cell viability and activity of catalase and decreased the level of intracellular reactive oxygen species and malondialdehyde, as well as the apoptosis rate induced by H₂O₂ (p < 0.05). Resveratrol up-regulated the expression of NRF2, p-NRF2, p-AKT, and p-P38 proteins and decreased the levels of cleaved caspase-3 and cleaved caspase-9 and the ratio of Bax to Bcl-2 in H₂O₂-induced IDECs (p < 0.05). Our findings revealed that resveratrol might alleviate oxidative stress by the PI3K/AKT and P38 MAPK signal pathways and inhibit apoptosis by altering the levels of cleaved caspase-3, cleaved caspase-9, Bax, and Bcl-2 in IDECs exposed to H₂O₂.     

Study on Extraction and Antioxidant Activity of Flavonoids from Hemerocallis fulva (Daylily) Leaves

Hemerocallis fulva is a medical and edible plant. In this study, we optimized the ultrasound-assisted extraction (UAE) process of extracting flavonoids from Hemerocallis fulva leaves by single-factor experiments and response surface methodology (RSM). The optimum extraction conditions generating the maximal total flavonoids content was as follows: 70.6% ethanol concentration; 43.9:1 mL/g solvent to sample ratio; 61.7 °C extraction temperature. Under the optimized extraction conditions, the total flavonoid content (TFC) in eight Hemerocallis fulva varieties were determined, and H. fulva (L.) L. var. kwanso Regel had the highest TFC. The cytotoxicity of the extract was studied using the Cell Counting Kit-8 (CCK-8 assay). When the concentration was less than 1.25 mg/mL, the extract had no significant cytotoxicity to HaCaT cells. The antioxidant activity was measured via chemical antioxidant activity methods in vitro and via cellular antioxidant activity methods. The results indicated that the extract had a strong ABTS and •OH radical scavenging activity. Additionally, the extract had an excellent protective effect against H₂O₂-induced oxidative damage at a concentration of 1.25 mg/mL, which could effectively reduce the level of ROS to 106.681 ± 9.733% (p < 0.001), compared with the 163.995 ± 6.308% of the H₂O₂ group. We identified five flavonoids in the extracts using high-performance liquid chromatography (HPLC). Infrared spectroscopy indicated that the extract contained the structure of flavonoids. The results showed that the extract of Hemerocallis fulva leaves had excellent biocompatibility and antioxidant activity, and could be used as a cheap and potential source of antioxidants in the food, cosmetics, and medicine industries.     

Exogenous Melatonin Activating Nuclear Factor E2-Related Factor 2 (Nrf2) Pathway via Melatonin Receptor to Reduce Oxidative Stress and Apoptosis in Antler Mesenchymal Stem Cells

Antler growth depends on the proliferation and differentiation of mesenchymal stem cells (MSCs), and this process may be adversely affected by oxidative stress. Melatonin (MLT) has antioxidant functions, but its role in Cervidae remains largely unknown. In this article, flow cytometry, reactive oxygen species (ROS) identification, qPCR, and other methods were used to investigate the protective mechanism of MLT in H₂O₂-induced oxidative stress of antler MSCs. The results showed that MLT significantly increases cell viability by relieving the oxidative stress of antler MSCs. MLT inhibits cell apoptosis by protecting mitochondrial function. We blocked the melatonin receptor with luzindole (Luz) and found that the receptor blockade significantly increases H₂O₂-induced hyperoxide levels and causes significant inhibition of mitochondrial function. MLT treatment activates the nuclear factor E2-related factor 2 (Nrf2) antioxidant signaling pathway, up-regulates the expression of NAD(P)H quinone oxidoreductase 1 (NQO1) and other genes and it could inhibit apoptosis. In contrast, the melatonin receptor blockade down-regulates the expression of Nrf2 pathway-related genes, but significantly up-regulates the expression of apoptotic genes. It was indicated that MLT activates the Nrf2 pathway through the melatonin receptor and alleviates H₂O₂-induced oxidative stress and apoptosis in antler MSCs. This study provides a theoretical basis for further studying the oxidative stress and antioxidant process of antler MSCs and, thereby, increasing antler yields.     

Polyphenolic Extracts from Spent Coffee Grounds Prevent H2O2-Induced Oxidative Stress in Centropomus viridis Brain Cells

Oxidative stress in aquatic organisms might suppress the immune system and propagate infectious diseases. This study aimed to investigate the protective effect of polyphenolic extracts from spent coffee grounds (SCG) against oxidative stress, induced by H₂O₂, in C. viridis brain cells, through an in vitro model. Hydrophilic extracts from SCG are rich in quinic, ferulic and caffeic acids and showed antioxidant capacity in DPPH, ORAC and FRAP assays. Furthermore, pretreatment of C. viridis brain cells with the polyphenolic extracts from SCG (230 and 460 µg/mL) for 24 h prior to 100 µM H₂O₂ exposure (1 h) significantly increased antioxidant enzymes activity (superoxide dismutase and catalase) and reduced lipid peroxidation (measured by MDA levels). These results suggest that polyphenols found in SCG extracts exert an antioxidative protective effect against oxidative stress in C. viridis brain cells by stimulating the activity of SOD and CAT.     

Identification of a Sesquiterpene Lactone from Arctium lappa Leaves with Antioxidant Activity in Primary Human Muscle Cells

Many pathologies affecting muscles (muscular dystrophies, sarcopenia, cachexia, renal insufficiency, obesity, diabetes type 2, etc.) are now clearly linked to mechanisms involving oxidative stress. In this context, there is a growing interest in exploring plants to find new natural antioxidants to prevent the appearance and the development of these muscle disorders. In this study, we investigated the antioxidant properties of Arctium lappa leaves in a model of primary human muscle cells exposed to H₂O₂ oxidative stress. We identified using bioassay-guided purification, onopordopicrin, a sesquiterpene lactone as the main molecule responsible for the antioxidant activity of A. lappa leaf extract. According to our findings, onopordopicrin inhibited the H₂O₂-mediated loss of muscle cell viability, by limiting the production of free radicals and abolishing DNA cellular damages. Moreover, we showed that onopordopicrin promoted the expression of the nuclear factor-erythroid-2-related factor 2 (Nrf2) downstream target protein heme oxygenase-1 (HO-1) in muscle cells. By using siRNA, we demonstrated that the inhibition of the expression of Nrf2 reduced the protective effect of onopordopicrin, indicating that the activation of the Nrf2/HO-1 signaling pathway mediates the antioxidant effect of onopordopicrin in primary human muscle cells. Therefore, our results suggest that onopordopicrin may be a potential therapeutic molecule to fight against oxidative stress in pathological specific muscle disorders.     

Contact-electro-catalysis for Direct Synthesis of H2O2 under Ambient Conditions

Hydrogen peroxide (H₂O₂) is an indispensable basic reagent in various industries, such as textile bleach, chemical synthesis, and environmental protection. However, it is challenging to prepare H₂O₂ in a green, safe, simple and efficient way under ambient conditions. Here, we found that H₂O₂ could be synthesized using a catalytic pathway only by contact charging a two-phase interface at room temperature and normal pressure. Particularly, under the action of mechanical force, electron transfer occurs during physical contact between polytetrafluoroethylene particles and deionized water/O₂ interfaces, inducing the generation of reactive free radicals (⋅OH and ⋅O₂⁻ ), and the free radicals could react to form H₂O₂, yielding as high as 313 μmol L⁻¹ h⁻¹. In addition, the new reaction device could show long-term stable H₂O₂ production. This work provides a novel method for the efficient preparation of H₂O₂, which may also stimulate further explorations on contact-electrification-induced chemistry process.     

Host-guest interactions based supramolecular complexes self-assemblies for amplified chemodynamic therapy with H2O2 elevation and GSH consumption properties

Although endogenous H₂O₂ is overexpressed in tumor tissue, the amount of endogenous H₂O₂ is still insufficient for chemodynamic therapy (CDT). In addition, the abundant cellular glutathione (GSH) could also consume ^?OH for reduced CDT. Thus, the elevation of H₂O₂ and the consumption of GSH in tumor tissue are essential for the increased ^?OH yield and amplified CDT efficacy. In this paper, host-guest interactions based supramolecular complexes self-assemblies (SCSAs) were fabricated by incorporating cinnamaldehyde (CA) and PEG-modified cyclodextrin host units (mPEG-CD-CA) with ferrocene-(phenylboronic acid pinacol ester) conjugates (Fc-BE) on the basis of CD-induced host-guest interactions. After being internalized by cancer cells, CA can be released from SCSAs through the pH-responsive acetal linkage, elevating the H₂O₂ level by activating NADPH oxidase. Then, Fc can catalyze the H₂O₂ to higher cytotoxic hydroxyl radicals (^?OH). Moreover, quinone methide (QM) can be produced through H₂O₂-induced aryl boronic ester rearrangement and further consume the antioxidant GSH. In vitro and in vivo experiments demonstrate that SCSAs can be provided as potential amplified CDT nanoagents.     

A study of the antioxidative behavior of phenolic acids, in aqueous herb extracts, using a dsDNA biosensor

Electrochemical DNA biosensors are promising tools for the fast, inexpensive and simple in vitro analysis for the determination of free radicals and antioxidants. High concentrations of antioxidants in such compounds as phenolic acids and plant extracts, act as free radical terminators which reduce the effect of the oxidative dam-age on DNA. The electrochemical behavior of three representative phenolic acids, caffeic acid, gallic acid and trolox were studied by cyclic voltammetry. Moreover, the determination of the above antioxidants under the optimized conditions (scan rate, deposition potential and time) using differential pulse voltammetry was also investigated. In vitro studies focused on their antioxidative effect were performed by adsorptive transfer stripping voltammetry and dsDNA biosensor. Using Fenton’s system, with FeSO₄ and H₂O₂ was chosen as a strong oxidative system. This biosensor was applied as a screening antioxidant test in order to estimate the antioxidant capacity of aqueous herb extracts.      

Phytochemical analysis,UPLC-ESI-Orbitrap-MS analysis,biological activity,and toxicity of extracts from Tripleurospermum limosum (Maxim.) Pobed

Tripleurospermum limosum (TL) has been used in folk medicine to treat gastritis. Toward the further development and use of TL, we report the phytochemical profiling, determination of active components, and antioxidant and enzyme inhibitory activities of TL. Nineteen compounds were identified by ultra-performance liquid chromatography-electrospray ionization-orbitrap-mass spectrometry for the first time in this plant. Phytochemical studies indicated that TL contained 11 types of phytochemicals. The active components [total carbohydrate content (TCC), total protein content (TP_roC), total triterpenoid content (TTC), total phenolic content (TP_heC), total flavonoid content (TFC), total phenolic acid content (TPAC), condensed tannin content (CTC), and gallotannin content (GC)] of eight different solvent extracts were determined by ultraviolet–visible spectrophotometry. Aqueous extract had highest TP_roC, TP_heC, and GC values. Methanol extract exhibited highest TCC and TFC values. Ethanol extract showed highest TPAC and CTC values and dichloromethane extract exhibited highest TTC value. Methanol extract showed strongest ability to scavenge 2,2-diphenyl-1-picrylhydrazyl radicals, 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt cation radicals, and hydroxyl radicals, and also exhibited highest antioxidant activity in ferric-reducing antioxidant power and cupric ion-reducing antioxidant capacity assays. Best iron and copper chelating activity and H₂O₂ scavenging ability were shown by aqueous extract. Ethanol extract showed strongest ability to scavenge superoxide radicals and effectively prevent β-carotene bleaching. Acetone extract had highest inhibitory activity toward α-glucosidase, α-amylase, and xanthine oxidase. Ethyl ether extract had highest inhibitory activity towards urease and angiotensin converting enzyme. Aqueous and ethanol extracts had strongest inhibitory activity toward acetylcholinesterase. Methanol extract showed highest inhibitory activity toward tyrosinase. Methanol extract showed good stability and antioxidant capacity during heating, at different pH values, and after in vitro digestion and had low toxicity. The efficacy of methanol extract in stabilizing olive and sunflower oils was studied, the results suggested that methanol extract had a protective effect on the primary oxidation of the two oils. TL may be useful as a source of active components for application in human nutrition and/or phytomedicine and methanol extract of TL could be used as a natural oil stabiliser.     

Pathways of advanced oxidation of phenol by Fenton's reagent—Identification of oxidative coupling intermediates by extractive acetylation

Homogeneous Fenton reaction (H₂O₂/Fe²⁺ system) using significantly substoichiometric concentrations of H₂O₂ oxidant to oxidize phenol was characterized focusing on the formation of stable aromatic intermediates. Beyond the most abundant benzenediols, the pattern of aromatic intermediates was chiefly characterized by hydroxylated biphenyls and diphenyl ethers with different degrees of hydroxylation. Hydroxylated dibenzofurans (DBF), p,p′-dioxins, as well as highly condensed aromatic intermediates including polyols of polycyclic aromatic hydrocarbons (PAHs), could also be detected, but in lower concentrations. The formation of aromatic intermediates could be predicted on the basis of oxidative coupling reactions of resonance-stabilized radicals generated by the attack of the highly reactive hydroxyl radicals (OH*) on phenol. GC/MS identification of oxidative coupling intermediates was performed after derivatization of the solvent extracts. Derivatization reactions included silylation to give TMS (trimethylsilyl) ethers, as well as single-step extractive acetylation using acetic anhydride in alkaline aqueous solutions (pH 10.5) to give acetates. Solvent extraction of aqueous solutions, a prerequisite to generate TMS ethers, caused strong discrimination of polyols due to their low distribution coefficients in non-polar solvents. This discrimination could be overcome by extracting the in-situ formed acetates of the intermediates. Extractive acetylation allowed the detection of tri-, tetra-, and penta-hydroxylated aromatic intermediates generated by Fenton oxidation processes, which have been overlooked upto now. Thus, extractive acetylation to detect stable aromatic intermediates covering a wide range of hydroxylation degrees can foster the understanding, monitoring, and management of advanced oxidation processes, especially in the field of wastewater treatment.     

Evaluation of Antioxidant and Cytotoxic Activity of Hydro-Ethanolic Extracts Obtained from Steiractinia aspera Cuatrec

In this work, the antioxidant activity of the hydro-ethanolic extracts of the leaves, flowers, and aerial parts of Steiractinia aspera Cuatrec, both fresh and post-distillation, was evaluated by ABTS^+·, FRAP, H₂O₂ and DPPH assays. The cytotoxic activity was evaluated in MCF-7, MCF-10A and HT-29 cell lines. The hydro-ethanolic extracts were obtained by matrix solid-phase dispersion (MSPD) and ultrasound-assisted solvent extraction (SE). The fresh-leaf MSPD extract had the highest antioxidant activity, and the post-distillation leaf ultrasound-assisted SE extract had the highest cytotoxicity in the MCF-7 breast cancer cell line, although not selective, which was evaluated by sulforhodamine B assay. On the other hand, ROS was evaluated by flow cytometry which showed that post-distillation leaf extract is pro-oxidant. Chlorogenic acid, kaempferol-3-glucoside and quercetin were found in the fresh leaves’ extracts, according to HPLC-DAD. PLC-DAD permitted the isolation of p-coumaric acid, E-3-(4-(((E)-3-(3,4-dihydroxyphenyl) acryloyl) oxy)-3-hydroxyphenyl) acrylic acid and a diglucosylated derivative of ursolic acid, which were analyzed by ¹H and ¹³C NMR. Our results suggest that the fresh leaf extract of Steiractinia aspera Cuatrec has potential use for antioxidant applications.     

Preparation of Antioxidant Protein Hydrolysates from Pleurotus geesteranus and Their Protective Effects on H2O2 Oxidative Damaged PC12 Cells

Pleurotus geesteranus is a promising source of bioactive compounds. However, knowledge of the antioxidant behaviors of P. geesteranus protein hydrolysates (PGPHs) is limited. In this study, PGPHs were prepared with papain, alcalase, flavourzyme, pepsin, and pancreatin, respectively. The antioxidant properties and cytoprotective effects against oxidative stress of PGPHs were investigated using different chemical assays and H₂O₂ damaged PC12 cells, respectively. The results showed that PGPHs exhibited superior antioxidant activity. Especially, hydrolysate generated by alcalase displayed the strongest 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (91.62%), 2,2-azino-bis (3-ethylbenzothia zoline-6-sulfonic acid) (ABTS) radical scavenging activity (90.53%), ferric reducing antioxidant power, and metal ion-chelating activity (82.16%). Analysis of amino acid composition revealed that this hydrolysate was rich in hydrophobic, negatively charged, and aromatic amino acids, contributing to its superior antioxidant properties. Additionally, alcalase hydrolysate showed cytoprotective effects on H₂O₂-induced oxidative stress in PC12 cells via diminishing intracellular reactive oxygen species (ROS) accumulation by stimulating antioxidant enzyme activities. Taken together, alcalase hydrolysate of P. geesteranus protein can be used as beneficial ingredients with antioxidant properties and protective effects against ROS-mediated oxidative stress.     

Assessment of antioxidant and cytotoxic potential of silver nanoparticles synthesized from root extract of Reynoutria japonica Houtt

Free radicals, mostly consist of reactive oxygen species, are generated in human body by several exogenous and endogenous systems. Overproduction of free radicals is known to cause several degenerative disorders including cancer. The aim of this study is to synthesize silver nanoparticles (AgNPs) using root extract of Reynoutria japonica and to investigate its antioxidant and cytotoxic potential. AgNPs were synthesized by green approach and subsequently characterized using UV–vis spectroscopy, SEM, TEM, FTIR, XRD, EDS and DLS. The antioxidant activity was investigated using DPPH, FRAP, H₂O₂, and ABT?⁺ radical scavenging assays while the cytotoxic effect was assessed using different human cancer cell lines including lung (A549), liver (Hep-G2) and breast (MDA-MB-231) by MTS assay. Moreover, the specificity of NPs was assessed against two normal human cell lines e.g. alveolar and renal primary epithelial cells (HPAEpiC and HRPTEpiC). The UV–vis spectra confirmed the synthesis of AgNPs by producing a characteristic peak at 410 nm. Further analysis confirmed that AgNPs were crystalline in nature, predominantly spherical in shape, with an average width and area of 17.34 nm and 164.46 nm², respectively. DLS analysis revealed that NPs possess a high negative zeta potential value (?28.5 mV), thus facilitating its electrostatic stabilization. AgNPs showed dose dependent antioxidant activity against DPPH, FRAP, H₂O₂ and ABTS with IC₅₀ values 19.25, 22.45, 24.20 and 18.88 µg/ml, respectively. The AgNPs depicted significant cytotoxic effects against A549, Hep-G2 and MDA-MB-231 cell lines with IC₅₀ values of 4.5, 5.1 and 3.46 µg/ml, respectively. Moreover, the NPs exhibited highest selectivity index (>2.0) for A549, Hep-G2 and MDA-MB-231, confirming its specificity towards cancer cell lines. In conclusion, AgNPs prepared from root extract of R. japonica possess strong antioxidant and cytotoxic potential which suggests that they should be investigated further in order to develop safe and effective antioxidant and/or cytotoxic formulations.