Free Radical Activity Research Articles

Biochar coupling induced charge transfer switching of a NiAl2O4/NiCr2O4 photocatalyst to enhance photocatalytic degradation of tetracycline hydrochloride

A series of novel (NiAl2O4 (NAO)/NiCr2O4 (NCO)) (S1)/GL heterojunction photocatalysts, denoting as x%GL/S1 (x = 5, 10, 15 and 20), were prepared by the polyacrylamide gel method combined with low temperature sintering technique. Various characterizations confirm that there is special interfacial contact and charge transfer between NAO, NCO and GL. The 10%GL/S1 heterojunction exhibited the best photocatalytic activity and cyclic stability for the degradation of tetracycline hydrochloride (TC). Compared to NAO, NCO and NAO/NCO, the degradation efficiency of 10%GL/S1 was significantly improved, and the degradation percentage reached 83.2% within 30 min. The activity of 10%GL/S1 was studied in relation to catalyst content, drug concentration, pH value, water quality, and co-existing anion. Trapping experiments and free radical verification experiments confirmed that the holes, hydroxyl radicals and superoxide radicals played crucial roles in the photocatalysis process. Possible pathways for TC degradation were studied by HPLC-MS, and the ecotoxicity of TC and its degradation intermediates was evaluated by T.E.S.T. software. The charge transfer and photocatalytic mechanisms confirm that the introduction of GL enhances the interfacial interaction between the components, promotes the carrier migration efficiency, provides a large number of active sites for 10%GL/S1 heterojunction, and produces active free radicals after redox reaction with photoinduced electrons, effectively improving the degradation efficiency of TC.

Melatonin levels in the follicular fluids and its correlation with ICSI Outcomes

Background: Melatonin is a hormone mainly synthesized and secreted from the pineal gland. The daily rhythm of circulatory melatonin is released in very low concentrations during the day and high levels at night. Melatonin has many functions beside regulation of circadian rhythm including immune system and autonomic cardiovascular regulation but the main melatonin function is antioxidant action and detoxification of free radicals. Patients and method: This cross sectional study was conducted during the period starting from November 2018 to May 2019. Eighty infertile female aged range 18–46 years were enrolled in the present study, the patients were undergoing controlled ovarian induction for IVF /ICSI treatment. All patents were divided into 3 groups according to age, FSH, E2, AMH and ovarian respond to controlled ovarian stimulation (COS) protocols. The follicular fluid melatonin measured at oocyte retrieval day using enzyme linked immunosorbent assay (ELISA). Results: There was significant difference in follicular fluid melatonin level between the three studied groups (p=0.031). There was also a positive significant correlation between follicular fluid melatonin with MII oocytes (r=0.343; p= 0.024), grade I embryo (r=0.375; p= 0.003) and AMH (r = 0.279; p= 0.027), on the other hand there was a negative significant correlation between follicular fluid melatonin and serum FSH (r = - 0.331; p= 0.016). There was also no significant difference of follicular fluid melatonin levels between pregnant and non-pregnant females (p=0.083). Conclusion: Melatonin levels in follicular fluid improve the oocytes and embryo qualities but have no effect in positive pregnancy rate.

A Novel BiOBr/CAU-17 Composite with Enhanced Photo-Catalytic Performance for Dye Degradation and Removal of Tetracycline Antibiotic Under Visible Light.

In order to improve the low specific surface area and high recombinant light generation carriers of BiOBr, loading BiOBr onto suitable Metal Organic Frameworks (MOFs) is an effective strategy to unleash its efficient visible light response and intrinsic catalytic activity. In this study, using classic MOF CAU-17 as a precursor, using a straightforward co-precipitation technique, four BiOBr/CAU-17 composites with distinct MOF contents values BCAU-1, BCAU-2, BC, AU-3, and BCAU-4 were created, and their photo-catalytic characteristics were examined. The BCAU-2 composite exhibited much higher photo-catalytic degradation efficiency for Rhodamine B (RhB) and Tetracycline (TC) than the pristine materials, counter compositions, and early reported materials. XRD, SEM, TEM, XPS, and EDX results revealed the strong synergistic photo-catalytic effect of BiOBr and CAU-17. The photocatalytic degradation of TC was significantly enhanced by the BiOBr bimetal modification, with the 2 wt.% BiOBr/CAU-17 nanocomposite achieving an 87.2 % degradation of TC and 82 % Total Organic Carbon (TOC) removal within 60 min. The high photo-degradation efficiency of BCAU-2 composite should be attributed to the efficient transfer of photo-generated carriers at interfaces and the synergistic effect between BiOBr/CAU-17. Furthermore, the experiments on the capture of the active species proved that the main active free radicals involved in the degradation of RhB and TC are attributed to the photo-induced holes h+ and ⋅ O2 - under visible light. The catalyst's efficacy is corroborated by the outcomes of photoluminescence spectroscopy and photo current response. This study offers a new understanding for the design of green synthesis schemes for photo-catalytic dye degradation and removal of certain antibiotics from the aquatic environment.

Rape straw biochar-assisted preparation of flower-like BiOCl with enriched oxygen vacancies for efficient photocatalytic CO2 reduction and pollutants degradation

Utilizing photocatalytic technology to transform CO2 into high added value chemical products has represented an effective strategy for alleviating the climate problems that have arisen due to excessive CO2 emissions. As a typical bismuth-based photocatalyst, BiOCl has garnered widespread attention due to its unique layered structure and low toxicity. However, the low light utilization efficiency and the rapid recombination of e−/h+ pairs severely hinder the practical application of BiOCl. Introducing oxygen vacancies (OVs) into BiOCl has been demonstrated to be one of the effective strategies for enhancing the photocatalytic performance of BiOCl. However, introduction of OVs through a mild and cost-effective approach remains a significant challenge. In this work, we developed a strategy for introducing OVs on BiOCl, which indues the growth of BiOCl into flower-like spherical structures and introduction of abundant OVs through addition of rape straw biochar (RC) under hydrothermal conditions. The synergistic interaction of RC and OVs endows with BiOCl more active sites as well as higher photogenerated carriers (e−/h+) separation efficiency. When the mass ratio of RC to BiOCl is 0.5 % (RC-0.5), the sample demonstrates the best performance, conversion of CO2 to CO on the sample is 4.0 μmol g−1 h−1, which is 3.08 times higher than that on the reference BiOCl. Additionally, versatility of the photocatalysts was further evaluated through photocatalytic degradation of rhodamine B (RhB) and perfluorooctanoic acid (PFOA). The degradation rate constant of RhB and PFOA on the RC-0.5 sample is 0.0642 min−1 and 0.00566 min−1, respectively, which is 2.26 times and 0.43 times higher than that on the reference BiOCl. Total organic carbon (TOC) experiments demonstrate that RhB can be effectively mineralized into CO2, H2O and small molecules on the photocatalyst. The main reactive species involved in the photocatalytic degradation process were investigated through active free radical trapping experiments and electron paramagnetic resonance (EPR). This work provides a viable strategy for the development of high-performance BiOCl photocatalysts for environmental applications.

Gastrointestinal toxicity following sub-acute exposure of erythrosine in rats: biochemical, oxidative stress, DNA damage and histopathological studies.

Erythrosine, a synthetic food dye, has been controversial due to its potential health risks. This study examines the effect of erythrosine on activity of antioxidative enzymes, oxidative stress indices, DNA damage through comet assay, and histopathological changes on stomach, intestine, and colon over a period of 28 days in rats. Twenty-four rats were randomly divided into four groups (n = 6). The first is the control group and then one each for three doses of erythrosine based on acceptable daily intake (¼ ADI, ½ ADI, and ADI, 0.1 mg/kg body weight). The results revealed that with increasing dosages the activity of catalase decreased in stomach and intestine but in colon, the catalase activity increased. Superoxide dismutase and glutathione-S-transferase activity decreased in dose-dependent manner in all three tissues. While, in stomach and intestine, the acetylcholinesterase activity showed increment in ¼ ADI dose group and then declined in ½ ADI and ADI dose-administered rats. The oxidative stress indicators showed elevated levels of lipid peroxidation, hydrogen peroxide concentration, and lactate dehydrogenase activity suggesting heightened free radical activity and potential oxidative damage. The comet test was used to evaluate DNA damage, revealing substantial damage in the erythrosine administered groups. Histopathological examination showed inflammatory infiltration and other degenerative changes in gastrointestinal tract, highlighting the dye's adverse effects. The research underscores the need for a comprehensive reevaluation of the safety and toxicity of food dyes like erythrosine, especially considering the inconsistencies in existing studies regarding the dye's safety.

Square-wave pulsed potential driven electrocatalytic degradation of 4-chlorophenol using Fe-Ni/rGO/PPy@NF three dimensional electrode

To develop an energy-efficient system for the removal of chlorinated organic pollutants, Fe-Ni/reduced graphite oxide/polymerized polypyrrole@nickel foam was constructed as a catalytic cathode for pulsed electrocatalytic degradation, where cathode-catalyzed production of hydrogen radicals (H*) and hydroxyl radical (·OH) generated at the anode led to dechlorination of 4-chlorophenol (4-CP), and dechlorination products were mineralized and degraded under the action of·OH. When energy was continuously supplied to the reaction system in the constant potential mode, the 4-CP concentration near the electrode was insufficient, limiting the reaction rate. Conversely, in the square-wave pulsed potential mode, mass transfer limitations were mitigated, significantly enhancing reaction efficiency and reducing energy consumption. At −1.2 V (vs. Ag/AgCl), the 4-CP removal efficiency reached 93.79 % in the pulsed potential mode, surpassing the constant potential mode's performance of 81.40 %. The synergistic periodic oscillation of the potential, direct electron transfer, and catalytic generation of active free radicals in the pulsed potential mode reduced intermediate concentrations and increased 4-CP mineralization, while the degradation pathway remained unchanged. This research presents a method for the efficient treatment of chlorinated organic pollutants in water using pulsed electrocatalytic degradation.

Phytochemical Profiling and Bioactive Properties of Essential Oils from Endemic Palestinian Satureja thymbrifolia.

Despite several studies on the Satureja L. genus, the chemical composition and biological activities of the traditional medicinal plant Satureja thymbrifolia (White Thyme), a Palestinian endemic species, are still unknown. It grows in arid regions and is used by Bedouins as a traditional medicinal herb. This study aimed to investigate S. thymbrifolia essential oils (EOs), mainly from its phytochemical pattern and biological properties. The GC-MS study identified p-cymene (48.53%) and thymol (23.27%) as the leading EOs components. Compared to Trolox, the EOs showed potential anti-DPPH free radical activity and had broad-spectrum antimicrobial potentials, with MIC values ranging from 0.13 ± 0.05 to 25 ± 0.00 µL/mL. They were most effective against Candida albicans species. The S. thymbrifolia EOs most effectively eliminated cancer cells when tested against CaCo-2 and HeLa cell lines (IC50 values of 192.15 ± 2.47 and 194.80 ± 1.87 µg/mL, respectively). The present investigation is the first documented study of S. thymbrifolia EOs' phytochemical composition and bioactivities. The results revealed that S. thymbrifolia EOs have potential antioxidant, antimicrobial, and cytotoxic effects. These outcomes emphasized S. thymbrifolia EO's potential dietary, pharmacological, and cosmetic applications.

Cu‐Doped 0D Bi2WO6 Nanoparticles for Efficient Visible‐Light‐Driven Photocatalytic Tetracycline Degradation

AbstractBismuth‐based photocatalysts have been widely employed in the photocatalytic degradation of organic pollutants in wastewater. However, the lack of rational structural design and the slow generation of active free radicals have hindered its efficiency. Here, we stabilized Bi2WO6 nanoparticles by wrapping them with hydroxyl groups, introduced metal Cu doping, and underwent an annealing process to construct Cu‐BiNP nanocatalysts with exposed active sites. Under visible light irradiation, 0.03Cu‐BiNP achieved a 94.5% TC degradation efficiency, which is 15.8 times higher than the rate of bulk BiWO. The 0D structure endows Cu‐BiNP with ample opportunities for O2 adsorption and activation, and Cu atomic doping reduces the bandgap and increases the oxygen vacancy, promoting the generation of active oxygen species. This work demonstrates the rapid charge separation and activation of O2 to generate active oxygen species by 0D bismuth‐based nanocatalysts in photocatalytic oxidation reactions, providing a scalable nanocatalyst platform for TC photocatalytic degradation.

High performance long-afterglow phosphor-based ZnIn2S4/Sr2MgSi2O7:Eu2+,Dy3+ photocatalyst capable of dark state long-term application for photocatalytic sterilization

Eco-friendly photocatalytic sterilization utilizing solar energy via the generation of reactive radicals excited by light irradiation devastating bacterial cells and mineralizing organic pollutants effectively exhibits vast application potential in marine biofouling prevention due to the abundant solar energy available in the ocean. Focusing on the issue of the cessation of photocatalytic processes in the absence of light, in this study, we selected the long afterglow material Sr2MgSi2O7:Eu2+,Dy3+ (SMSO), which exhibits persistent sky-blue luminescence after brief illumination, as the substrate for in situ compositing with the visible-light-responsive ZnIn2S4 (ZIS). The emission spectrum of SMSO partially overlaps with the absorption spectrum of ZIS, and their energy bands were well-matched. Consequently, the ZIS/SMSO=1:0.5 (mass ratio) exhibited the synergistic degradation and bactericidal performance under both light and dark conditions. ZIS/SMSO=1:0.5 exhibited the degradation rate of methyl orange (MO) of 72.4 % when exposed to 5 minutes of simulated sunlight, 2.6-fold increase compared to ZIS, and especially, it exhibited the sustained degradation rate of 38.7 % after 5 h in darkness. Besides, ZIS/SMSO=1:0.5 exhibited the bactericidal rate of 28.9 % under simulated visible light of 1 h, which was 2.9 and 2.5 times the bactericidal rate of ZIS and SMSO, respectively; and especially, after 6 h in darkness, it reached 64.4 %, which was 2.8 and 1.9 times the bactericidal rate of ZIS and SMSO, respectively. The Electron Spin Resonance (ESR) test validated the notably higher ·OH and ·O2- signals of the ZIS/SMSO=1:0.5 complex than those of individual components when exposed to light, and the sustained existence of ·OH signal even in darkness, revealing that the continuously generation of active free radicals even in the absence of light due to that the SMSO can continuously excite the ZIS. Combining with the in situ XPS analysis and the density functional theory calculations, an S-scheme heterojunction between ZIS and SMSO is formed which contribute to the higher yield of ·OH for ZIS/SMSO=1:0.5 under both light and dark conditions. And the calculation of the adsorption energies of ZIS and SMSO for O2 and OH- in the composite revealed that the ZIS component is more favorable for adsorbing O2, while the SMSO component is more favorable for adsorbing OH-. These analyses manifested the S-scheme electron transfer of the system. Finally, the ZIS/SMSO=1:0.5 composite of environmentally friendly broad-spectral-responsive ternary metal sulfides with the long afterglow materials is capable of a sustained degradation and bactericidal effect, not only under light irradiation but also in the subsequent darkness. It offers valuable insights into photocatalytic materials that overcome light availability limitations for preventing marine biofouling.

A detailed chemical kinetic model for methanol and ammonia co-oxidation under hydrothermal flames: Reaction mechanism and flame characteristics

A detailed chemical kinetic model for ammonia and methanol co-oxidation under hydrothermal flames was established with pressure and thermodynamic corrections. Simulation model was validated by comparing with experimental temperature rise, and methanol and ammonia removal efficiencies. Species evolutions, reaction paths, and reaction sensitivities for pure ammonia combustion, and ammonia and methanol co-oxidation under hydrothermal flames were analyzed. Ammonia concentration begins to decrease only when methanol is consumed in a certain amount in the ammonia and methanol co-oxidation under hydrothermal flames, indicating the addition of methanol promotes the degradation of ammonia. Moreover, reaction heat is more conductive to ignition and the conversion of ammonia to nitrogen than active free radicals provided from methanol. The ignition delay time presents a minimum as a function of ammonia/methanol concentration ratio, with the minimum values of ignition delay time present at approximately ωNH3/ωCH3OH = 1 for different methanol concentrations. Higher preheating temperatures favor more NOX but less N2O formation, while higher ammonia concentrations favor both NOX and N2O formations. The presence of ammonia increases the laminar flame speed and permits a lower extinction temperature, indicating the mixture of methanol and ammonia can improve the stability of hydrothermal flames.

Elemental Zn modulation of interfacial structure and in situ construction of (FeCoNiCuZn)O high-entropy oxide/ZnO heterojunction for photocatalytic Rhodamine B dyes

In this study, inspired by the lattice distortion effect of HEOs, we adopt a non-equimolar strategy, fixing the molar ratios of Fe, Ni, Cu, and Co while varying the molar ratio x of Zn/(FeNiCuCo) (x=0.25, 0.5, 1.0, 1.5 and 2.0) to synthesize the HEO-x compounds. With an increase in the Zn content, lattice distortion occurred in the spinel phase of the (FeNiCuZnCo)O HEO, resulting in the gradual precipitation of ZnO nanocrystals. The (220) crystal plane of the spinel phase closely connects with the (100), (002), and (101) crystal planes of the ZnO phase, forming nano-heterojunctions. The HEO-1.5 prepared by controlling the Zn element proportion exhibits a high photocatalytic degradation rate of Rhodamine B (RhB) of up to 99.45 %. The kinetic degradation rate of HEO-1.5 is 17 times higher than that of HEO-0.25, attributed to the nano-heterojunctions formed by the spinel phase and ZnO phase, facilitating effective separation of photogenerated electron-hole pairs, promoting the generation of active free radicals, and rapidly degrading RhB.

In-Vitro Evaluation of Antioxidant Potential of Colocasia esculenta Corms

Introduction: Colocasia esculenta Linn (family: Araceae; synonym: Arum esculentum Linn; Taro) is one of the most important tubers crops worldwide and has been employed for medicinal applications for a significant period. Traditionally, in Indian and Chinese medicine, taro is utilized for many years for medicinal applications such as hypoglycaemic, antifungal, antimicrobial, hepatoprotective, and nervine tonic Taking into consideration the traditional claims, C. esculenta has the potential to be a useful for antioxidant activity. With this perspective in mind, the current research aimed to investigate the antioxidant potential of C. esculenta corms. Method: In vitro antioxidant activity aqueous extract of C. esculenta corms was studied by DPPH method. Ascorbic acid was used as a reference standard. The absorbance of various concentrations of corm extract and ascorbic acid were measured by using UV–Visible Spectrophotometer and the percent radical scavenging activity (% RSA) of the DPPH free radical was measured. Results: The Radical scavenging activity of corm extract of C. esculenta at 400μg/mL was found to be 80.33% at absorbance 0.142. The IC50 value of C. esculenta was found to be 120.16μg/mL which was calculated by using y = 0.0952x+38.56 equation. The Radical scavenging activity of Ascorbic acid at 400μg/ml was found to be 87.67% at absorbance 0.089. The IC50 value of Ascorbic acidwas found to be 28.05μg/mL which was calculated by using y = 0.091x+47.43 equation. Conclusion: Our study indicates that the corm extract has the potential as an antioxidant agent, possibly inhibiting DPPH, when compared with standard ascorbic acid. However, the chemical constituents present in the extract such as saponins, steroids, carbohydrates, glycosides, tannins, flavonoids and proteins may be responsible for such activity.

Phosphorus heteroatom doped BiOCl as efficient catalyst for photo-piezocatalytic degradation of organic pollutant and unveiling the mechanism: Experiment and DFT calculation

A novel phosphorus heteroatom doped bismuth oxychloride (P-BiOCl) catalyst was synthesized and the photo-piezocatalytic degradation of rhodamine B dye performances were explored under the ultrasound vibration and light illumination. The P-BiOCl exhibited excellent photo-piezocatalytic degradation activity, such as an ultra-high reaction kinetic rate constant of 0.3961 min−1, efficient degradation efficiency (94.7 % within 8 min) and excellent stability compared to solely piezocatalysis and photocatalysis. More impressively, these outstanding performances of P-BiOCl exceeded pure BiOCl and most other catalytic materials systems. The relevant experimental and density functional theory (DFT) calculation results were exhibited to clarify enhanced photo-piezocatalytic mechanism. The introduction of P heteroatom could reduce the bandgap of BiOCl, modulate electronic structure and charge redistribution, provide novel electron channel to promote electron transfer and restrain charge carriers recombination. Additionally, P-doped could also enhance the adsorption of oxygen and water molecules, promote intrinsic catalytic activity, leading to the increased production of active free radicals ·O2– and ·OH, thus significantly boosting the efficiency of organic pollutant degradation. This work provides a comprehensive understanding of heteroatom doping enhancing photo-piezocatalytic activity and presents a potential new strategy for designing highly efficient catalysts for wastewater treatment.

Aging of microplastics and its photo-catalytic degradation of coexisting tetracycline

Photodegradation processes play a crucial role in the transforming of antibiotics in aqueous environments, while photochemical aging influences the properties of microplastics (MPs). In this study, the efficacy of ultraviolet (UV) irradiation in eliminating tetracycline (TC) was examined. Especially, TC degradation was mediated by polyethylene microplastics (PE-MPs) was subjected to aging through UV exposure and a combination of UV and thermal-activated persulfate treatments. The effects of MPs concentration, salinity, and pH on TC degradation were investigated. The characteristics of aging PE-MPs and the corresponding active free radicals were analyzed to understand the mechanism of TC degradation. The results showed that the existence of PE-MPs significantly influenced TC degradation under photosensitized conditions. However, as the concentration of PE-MPs increased, the degradation rate initially increased and subsequently declined. TC degradation increased from approximately 35 % to 85 % when pH increased from 3 to 11 mediated by aged PE-MPs. Moreover, the TC degradation ability increased with increasing salinity, and a higher aging degree facilitated the photodegradation of TC, achieving a removal rate of 62 %. At the same time, free radical quenching confirmed that the singlet oxygen (1O2), hydroxyl radical (OH), and superoxide radical (O2·−) produced all involved in the photolysis process of TC mediated by PE-MPs, especially 1O2. The analysis of the degradation products of TC and prediction of its toxicity revealed that the ecological risk associated with the degradation solution diminished compared with that of the TC mother solution.

Mechanism of adsorption and targeted degradation of antimicrobial micropollutant sulfamethoxazole in aquatic environments

FHWSB as an integrated absorptive catalyst, based on Walnut shell biochar (WSB) via hydrochloric acid modification and ferrous chloride impregnation, was prepared, reacted with H2O2 to generate active free radicals •OH and •O2−, which oxidized and degraded about 80% of micro-pollutant sulfamethoxazole (SMX) from water, effectively resolving micro-pollutants' removal being inefficient because of high toxicity, persistence, and bioaccumulation in existed methods. It was clarified the specific degradation pathways and mechanisms of SMX by FHWSB synergistic H2O2 via characterization and analysis assisted DFT calculations. Furthermore, it was found that the toxicity of a series of intermediates produced by SMX degraded continued to decline, consistent with its direction of degradation via toxicological analysis. The work provides a simple and feasible strategy for the effective removal of antibiotic micro-pollutants in aquatic environments.

Macroscopic behavior and kinetic mechanism of ammonium dihydrogen phosphate for suppressing polyethylene dust deflagration

In this paper, the inhibition effect of ammonium dihydrogen phosphate (NH4H2PO4) on the deflagration of polyethylene dust (C100H202) is studied by combining experimental tests with reaction molecular dynamics simulation (ReaxFF MD). The mechanism by which NH4H2PO4 inhibits C100H202 deflagration is revealed at the microscopic level. The experimental results demonstrate that the inhibition effect of NH4H2PO4 on C100H202 deflagration is positively correlated with its concentration, and the addition of NH4H2PO4 equivalent to 50 % of the mass of C100H202 can completely suppress the deflagration. The apparent activation energies for the decomposition of C100H202 and C100H202/50 %NH4H2PO4 are calculated using ReaxFF MD to be 97.11 kJ/mol and 124.78 kJ/mol, respectively, which are in agreement with the results obtained from thermogravimetric tests. Furthermore, ReaxFF MD is employed to calculate the types and quantities of deflagration products and free radicals before and after the addition of NH4H2PO4. The results indicate that the number of the main intermediate C2H4 decreases with the increasing addition of NH4H2PO4. Based on this, the generation and consumption pathways of C2H4 are traced. It is found that phosphorous groups such as HOPO and PO2 scavenge active free radicals like ·O and ·OH, thereby altering the formation and consumption pathways of C2H4, leading to a reduction in both its formation and consumption. Additionally, H2O and inert gases produced by the thermal decomposition of NH4H2PO4 also contribute to inhibiting the progression of C100H202 deflagration.

Optimization of Polyphenol Extraction Conditions from Rhizomes of Curcuma zedoaria with Antioxidant, Anti-Inflammatory and Anti-Diabetic Activities In Vitro

The recovery of polyphenol compounds is seen as an arduous task because polyphenol compounds are available as free aglycones, as sugar or ester conjugates, or as polymers with several monomeric components. The response surface method (RSM) as a tool to optimize the factors that affect extraction efficacy as well as to obtain maximum recovery of the compounds of interest. This study optimizes ultrasound-assisted polyphenol extraction from Curcuma zedoaria rhizomes using response surface methodology (RSM). Three variables were considered: Ethanol concentration (70 - 90 %, v/v), temperature (60 - 80 °C), and ultrasound time (15 - 25 min). Data were analyzed by ANOVA, yielding an R2 of 0.9993, a significant interaction effect (p < 0.0001), and an insignificant lack-of-fit test (p = 0.6684). Optimal conditions for maximum polyphenol content (TPC = 31.05 ± 0.53 mg GAE/g powder) were 80.02 % ethanol, 68 °C, 20.47 min ultrasound time, and 1/10 (w/v) raw material/solvent ratio. Experimental values matched RSM predictions, confirming successful extraction optimization from Curcuma zedoaria rhizomes. The polyphenol-rich optimum extract from Curcuma zedoaria rhizomes has been studied for its antioxidant, anti-inflammatory and anti-inflammatory properties in vitro. The results were found, the optimum extract of Curcuma zedoaria rhizomes could perform effective neutralization activities of free radicals performed in DPPH test (IC50 = 5.89 ± 0.23 µg/mL), NO· (IC50 = 5.89 ± 0.23 µg/mL) and ABTS·+ (IC50 = 8.28 ± 0.12 µg/mL). Besides, this optimum extract had the ability to protect red blood cell membranes and inhibit protein denaturation due to heat with IC50 times values ​​such as 29.06 ± 0.35 and 30.24 ± 0.32 µg/mL. In addition, it also significantly inhibited α-amylase, α-glucosidase enzyme activities with IC50 values ​​of 5.89 ± 0.23 and 9.62 ± 0.11 μg/mL, respectively. This investigation showed that the polyphenol-rich optimum extract from Curcuma zedoaria rhizomes was a promising antioxidant, anti-inflammatory and anti-diabetic agent. HIGHLIGHTS Using ultrasound and the Box-Behnken design to extract polyphenols from Curcuma zedoaria rhizomes can speed up and improve extraction efficiency. The goal of this study is to maximize the extraction parameters for polyphenols from the rhizomes of Curcuma zedoaria. There is strong agreement between the experimental data and the model that predicts the polyphenol content in the Box-Behnken design. In vitro biological activities such as anti-inflammatory, antidiabetic and antioxidant properties are significantly correlated with polyphenol concentration. The findings of our investigation show a noteworthy enhancement in the bioavailability of polyphenol compounds through increased extraction efficiency and bioactivity. GRAPHICAL ABSTRACT

Investigation of the profile of dry extracts of Iris hungarica leaves and rhizome to determine the cardioprotective activity in the rat model of doxorubicin cardiomyopathy

The search and creation of new cardioprotective drugs, especially of plant origin, with a prolonged effect and a minimum of side effects, is an urgent task to improve the prognosis of cardiovascular diseases, prevent the risk of developing complications, and increase the duration and quality of life of patients. Iris hungarica, from the Iridaceae family, has a long history of medicinal use in many countries of the world and is also recognized as a rich source of BAC. The aim. Study of the cardioprotective effect of dry extracts of leaves and rhizomes of Iris hungarica on the rat model of doxorubicin cardiomyopathy. Materials and methods. The research was conducted on 40 white outbred female rats, which were injected intraperitoneally with a solution of doxorubicin hydrochloride at a dose of 1 mg/kg, at the rate of 0.5 mL per 100 g of the animal's body weight, according to the scheme 2 times a week for 6 weeks. The cardiotoxic effect and protective properties of potassium orotate, dry extracts of leaves and rhizomes of steppe iris were evaluated by animal survival, determination of the relative heart mass ratio, functional state of the myocardium (ECG parameters) and biochemical parameters in blood serum and heart homogenate. Results and discussion. The analysis of indicators of the functional state of the conducting system of the heart shows that the 15-day use in the treatment of animals with doxorubicin cardiomyopathy of the dry extract of the leaves and rhizomes of Iris hungarica at a dose of 150 mg/kg demonstrates a cardioprotective effect at the initial stage. In the model of doxorubicin cardiomyopathy, the dry extracts of the leaves and rhizomes of steppe iris at a dose of 150 mg/kg showed a normalizing effect on biochemical parameters in blood serum and in heart homogenate and were not inferior to the action of the comparison drug potassium orotate at a dose of 100 mg/kg. The dry extract of the rhizomes of steppe iris revealed the most pronounced effect on metabolism in cardiomyocytes. The cardioprotective activity of the dry extract of the rhizomes of the Iris hungarica is defined as a cardioprotector - of the anabolic and antioxidant type - those that accelerate the recovery of the heart muscle, protect the heart muscle from the action of free radicals, preventing premature aging and wear. Conclusions. In the model of doxorubicin cardiomyopathy in rats, indicators of the functional state of the conducting system of the heart of animals after the use in the treatment of animals of the dry extracts of the leaves and rhizomes of steppe iris in a dose of 150 mg/kg demonstrate a cardioprotective effect at the initial stage, a normalizing effect on biochemical indicators in the blood serum and in the homogenate heart and are not inferior to the comparison drug potassium orotate in a dose of 100 mg/kg. The most pronounced effect of the dry extract of the rhizomes of Iris hungarica on the functional state of the myocardium and biochemical indicators in blood serum and heart homogenate was established. The dry extract of the rhizomes of steppe iris is a promising herbal remedy for the creation of a new drug with cardioprotective properties

Exopolysaccharide from Leuconostoc mesenteroides XR1: Yield optimization, partial characterization and properties

The production conditions of exopolysaccharide (EPS) from Leuconostoc mesenteroides XR1 were optimized by response surface methodology (RSM). Maximum EPS yield was 56.59 ± 0.51 g/L under fermentation conditions with 2.6 g/L ammonium citrate, initial pH 6.5 and temperature 23 °C, which was 6.21-fold greater than the EPS yield before optimization. Characterization of the chain conformation using Congo red test and circular dichroism (CD) showed that EPS exhibited a random coil structure in aqueous solution. The CD results revealed that the EPS concentration altered its hydrogen-bond interactions and chirality, but did not change its chain conformation. The average polydispersity index (PDI) of the EPS solution was only 27.16 %, indicating that it was uniformly distributed in the aqueous solution with high stability. The degradation temperature of EPS was 253.11 °C, indicating high thermal stability. EPS possessed the ability to scavenge activities of free radicals and was protective against oxidative stress-induced plasmid DNA damage. In addition, stable hydrogels could be formed at EPS concentrations above 5 % (w/v). These results collectively showed that EPS can be used commercially as an antioxidant and drug delivery carrier.

Antidiabetic potential of sea fish mass by inhibiting di-peptidyl peptidase-IV and augmenting glucagon-like peptide-1 on high lipid diet and streptozotocin induced diabetic rats

Many studies have revealed that sea fish is a rich source of nutrients, especially protein and there peptide. In this study, antidiabetic activity of the fish masses of three sea-fishes ‘volavetki’ (Panna microdon, Bleeker 1849), ‘ruli’ (Coilia dussumieri, Valenciennes 1848), ‘tapra’(Opisthopterus tardoore, Cuvier 1829) and one fresh-water fish ‘murola’(Amblypharyngodon mola, Hamilton 1822),evaluated high lipid diet (HLD) and STZ induced Type 2 Diabetic Mellitus (T2DM) rats. Supplementation of sea-fish masses and antidiabetic effect was monitored by fasting plasma blood glucose and HbA1c. Also, insulin, c-peptide, glucagon-like peptide-1, dipeptidyl peptidase-IV, glucokinase, glucose-6 phosphatase, superoxide dismutase, glutathione peroxidase, catalase, plasma total cholesterol, low density lipoprotein, triglycerides, high density lipoprotein and histopathology of free radical activity of pancreatic tissues were evaluated. Out of four fish masses, volavetki sea fish masses oral supplementation resulted in significant reduction of plasma blood glucose, HbA1c of T2DM rat. All other parameters in T2DM rats were returned to near normal by treatment of volavetki sea fish mass. Our findings strongly indicated that volavetki sea fish highly showed antidiabetic activity.