Covalent and hydrophobic interactions play important roles in the formaldehyde scavenging ability of banana condensed tannins in aqueous solution.

To characterize the interaction between banana condensed tannins (BCT) and formaldehyde as well as elucidate the involving mechanism, different techniques were utilized in the present study. Our results showed that BCT were a mixture of procyanidins and prodelphinidins with the degree of the polymerization of 2-9. With the increasing condensed tannin concentration (0.125-0.625 mg CE/mL), the formaldehyde scavenging ability of BCT (32.16-78.64 %) continuously enhanced. It was shown that formaldehyde could quench the fluorescence of BCT through a dynamic mechanism, while the binding of BCT and formaldehyde was a spontaneous process. According to the data of scavenging ability and spectroscopic analyse, the hydrophobic and covalent interactions between BCT and formaldehyde mainly contributed to the formaldehyde scavenging ability of BCT Moreover, the morphologies of BCT-formaldehyde complexes confirmed the interactions between BCT and formaldehyde as well. Therefore, BCT could be developed as promising formaldehyde scavengers during food production and processing in the future.

Hyaluronic acid methacrylate/Pluronic F127 hydrogel enhanced with spermidine-modified mesoporous polydopamine nanoparticles for efficient synergistic periodontitis treatment.

Bacterial infection, reactive oxygen species (ROS) accumulation, and persistent inflammation pose significant challenges in the treatment of periodontitis. However, the current single-modal strategy makes achieving the best treatment effect difficult. Herein, we developed a double-network hydrogel composed of Pluronic F127 (PF-127) and hyaluronic acid methacrylate (HAMA) loaded with spermidine-modified mesoporous polydopamine nanoparticles (M@S NPs). The PF-127/HAMA/M@S (PH/M@S) hydrogel was injectable and exhibited thermosensitivity and photocrosslinking capabilities, which enable it to adapt to the irregular shape of periodontal pockets. In vitro, the PH/M@S displayed multiple therapeutic effects, such as photothermal antibacterial activity, a high ROS scavenging capacity, and anti-inflammatory effects, which are beneficial for the multimodal treatment of periodontitis. The underlying anti-inflammatory mechanism of this hydrogel involves suppression of the extracellular regulated protein kinase 1/2 and nuclear factor kappa-B signalling pathways. Furthermore, in lipopolysaccharide-stimulated macrophage conditioned media, the PH/M@S effectively restored the osteogenic differentiation potential. In a rat model of periodontitis, the PH/M@S effectively reduced the bacterial load, relieved local inflammation and inhibited alveolar bone resorption. Collectively, these findings highlight the versatile functions of the PH/M@S, including photothermal antibacterial activity, ROS scavenging, and anti-inflammatory effects, indicating that this hydrogel is a promising multifunctional filling material for the treatment of periodontitis.

Bifunctional mesoporous HMUiO-66-NH2 nanoparticles for bone remodeling and ROS scavenging in periodontitis therapy.

Periodontal bone defects represent an irreversible consequence of periodontitis associated with reactive oxygen species (ROS). However, indiscriminate removal of ROS proves to be counterproductive for tissue repair and insufficient for addressing existing bone defects. In the treatment of periodontitis, it is crucial to rationally alleviate local ROS while simultaneously promoting bone regeneration. In this study, Zr-based large-pore hierarchical mesoporous metal-organic framework (MOF) nanoparticles (NPs) HMUiO-66-NH2 were successfully proposed as bifunctional nanomaterials for bone regeneration and ROS scavenging in periodontitis therapy. HMUiO-66-NH2 NPs demonstrated outstanding biocompatibility both in vitro and in vivo. Significantly, these NPs enhanced the osteogenic differentiation of bone mesenchymal stem cells (BMSCs) under normal and high ROS conditions, upregulating osteogenic gene expression and mitigating oxidative stress. Furthermore, in vivo imaging revealed a gradual degradation of HMUiO-66-NH2 NPs in periodontal tissues. Local injection of HMUiO-66-NH2 effectively reduced bone defects and ROS levels in periodontitis-induced C57BL/6 mice. RNA sequencing highlighted that differentially expressed genes (DEGs) are predominantly involved in bone tissue development, with notable upregulation in Wnt and TGF-ß signaling pathways. In conclusion, HMUiO-66-NH2 exhibits dual functionality in alleviating oxidative stress and promoting bone repair, positioning it as an effective strategy against bone resorption in oxidative stress-related periodontitis.

RICE LONG GRAIN 3 delays dark-induced senescence by downregulating abscisic acid signaling and upregulating reactive oxygen species scavenging activity.

Leaf senescence is a complex developmental process influenced by abscisic acid (ABA) and reactive oxygen species (ROS), both of which increase during senescence. Understanding the regulatory mechanisms of leaf senescence can provide insights into enhancing crop yield and stress tolerance. In this study, we aimed to elucidate the role and mechanisms of rice (Oryza sativa) LONG GRAIN 3 (OsLG3), an APETALA2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF) transcription factor, in orchestrating dark-induced leaf senescence. The transcript levels of OsLG3 gradually increased during dark-induced and natural senescence. Transgenic plants overexpressing OsLG3 exhibited delayed senescence, whereas CRISPR/Cas9-mediated oslg3 mutants exhibited accelerated leaf senescence. OsLG3 overexpression suppressed senescence-induced ABA signaling by downregulating OsABF4 (an ABA-signaling-related gene) and reduced ROS accumulation by enhancing catalase activity through upregulation of OsCATC. In vivo and in vitro binding assays demonstrated that OsLG3 downregulated OsABF4 and upregulated OsCATC by binding directly to their promoter regions. These results demonstrate the critical role of OsLG3 in fine-tuning leaf senescence progression by suppressing ABA-mediated signaling while simultaneously activating ROS-scavenging mechanisms. These findings suggest that OsLG3 could be targeted to enhance crop resilience and longevity.

Ultra-Small Copper-Based Multienzyme-Like Nanoparticles Protect Against Hepatic Ischemia-Reperfusion Injury Through Scavenging Reactive Oxygen Species in Mice.

Hepatic ischemia-reperfusion injury (IRI) is a severe complication that occurs in the process of liver transplantation, hepatectomy, and other end-stage liver disease surgery, often resulting in the failure of surgery operation and even patient death. Currently, there is no effective way to prevent hepatic IRI clinically. Here, it is reported that the ultra-small copper-based multienzyme-like nanoparticles with catalase-like (CAT-like) and superoxide dismutase-like (SOD-like) catalytic activities significantly scavenge the surge-generated endogenous reactive oxygen species (ROS) and effectively protects hepatic IRI. Density functional theory calculations confirm that the nanoparticles efficiently scavenge ROS through their synergistic effects of the ultra-small copper SOD-like activity and manganese dioxides CAT-like activity. Furthermore, the results show that the biocompatible CMP NPs significantly protected hepatocytes from IRI in vitro and in vivo. Importantly, their therapeutic effect is much stronger than that of N-acetylcysteamine acid (NAC), an FDA-approved antioxidative drug. Finally, it is demonstrated that the protective effects of CMP NPs on hepatic IRI are related to suppressing inflammation and hepatocytic apoptosis and maintaining endothelial functions through scavenging ROS in liver tissues. The study can provide insight into the development of next-generation nanomedicines for scavenging ROS.

Fractionation of Boswellia serrata oleogum resin essential oil by short-path molecular vacuum distillation: Unveiling potent biological activities and chemical composition.

Boswellia serrata produces oleo gum resin, a rich source of essential oil (EO). EOs, produced as secondary metabolites by medicinal plants, are employed for medicinal and therapeutic purposes. The present study aimed to investigate the yield, chemical composition, antioxidant (AO), antimicrobial, and hemolytic activity of B. serrata EO and its fractions and sub-fractions (SFs). The EO was extracted using the superheated steam extraction (SHSE) method at 140°C. Short-path molecular vacuum distillation was used to separate the EO into fractions and SFs. Gas chromatography-mass spectrometry analysis showed α-pinene, α-thujene, trans verbenol, and linalool as major components of EO. The AO potential was evaluated using a 2,2-diphenyl-1-picrylhydrazyl assay, % inhibition in a linoleic acid assay, H2O2 scavenging assay, and total AO content (TAOC) using a ferric reducing AO power assay. F2b SF exhibited the highest scavenging activity, with percentages of 95.77%, 96.20%, and 83.54%, respectively, whereas EO revealed the highest TAOC value of 115.94%. Antimicrobial activity was evaluated by disc diffusion, resazurin microtiter plate, and microdilution broth assays. F1c SF showed maximum antibacterial potential (high inhibition zone 17.65-38.28 mm and low minimum inhibitory concentration [MIC] 2.20-84.44 µg/mL). The EO showed the highest antifungal activity (high inhibition zone 12.58-25.81 mm and low MIC 35.18-225.17 µg/mL). Cytotoxicity was assessed by hemolytic assay, with the F1c SF showing the highest activity at 10.89%. It is concluded that SHSE is an effective technique for B. serrata EO extraction, and this EO can be utilized for various medicinal purposes.

Evaluation of oxidative stress, biochemical parameters and in silico markers in different pea accessions in response to drought stress.

KEY MESSAGE: ARG6 and ARG10 pea accessions exhibited better tolerance to drought by keeping drought-associated attributes stable and higher, that is, stable chlorophyll content, high antioxidant activity, and the presence of polymorphic bands with stress-responsive EST-SSR markers. Each year, a significant portion of crops is lost due to various abiotic stresses, and even pea (Pisum sativum) crop growth and yield are severely affected by the challenges posed by drought stress. Drought is a critical factor that limits crop growth and development, and its impact is exacerbated by changes in the magnitude of climatic conditions. Drought induces oxidative stress in plants, leading to the accumulation of high concentrations of reactive oxygen species that damage cell structures and vital functioning of cells. The primary objective was to identify stress-tolerant plants by evaluating different morphological and biochemical attributes, such as biomass, chlorophyll content, relative water content, ascorbate peroxidase (APX), superoxide dismutase (SOD), and DPPH scavenging activity, as well as protein, proline, and phenolic content. Our study revealed that pea accessions (ARG6 and ARG10) were more resilient to drought stress as their chlorophyll, relative water, protein, and proline contents increased under drought conditions. Antioxidant enzymes, such as SOD, APX, and DPPH activities, also increased under drought stress in ARG10 and ARG6, suggesting that these accessions could bolster the antioxidant defense system in response to drought stress. Based on putative (cellular, biological, and metabolic) functions, ten EST-SSR primers were selected for the amplification study. Three EST-SSR primers, AUMP06_110, AUMP18_300, and AUMP31_250, were used for ARG6 and ARG10. Based on the correlation between the presence or absence of specific EST-SSR alleles, various physiological and morphological traits, and DPPH scavenging activity, both ARG10 and ARG6 demonstrated resistance to drought stress.

UPLC-HRMS/MS Guided Isolation and NMR Investigation of Major Flavonoids from Enarthrocarpus strangulatus Boissier (Brassicaceae) with In Vitro Enzymes Inhibitory Potential.

Various members of the family Brassicaceae are economically important and traditionally used to treat many disorders. Among the family members, Enarthrocarpus strangulatusBoissier is a common Egyptian species that was rarely studied. Consequently, the current study aims to characterize its phytochemical composition and assess its potential bioactivity comprehensively. A metabolomics approach integrating UPLC-HRMS/MS-based molecular networking enabled the dereplication of  91 metabolites, including primary (i.e. organic acid, amino acids, fatty acids, and phospholipids) and secondary metabolites (i.e. glucosinolates, phenolic acids, and flavonoids). Among the 91 annotated features, 13 major metabolites were fully characterized following their isolation and purification. Exclusive of only three flavonoids, all the detected metabolites are described for the first time within this species. Furthermore, the crude extract and four major isolated flavonoids were subjected to in vitro biological screening, including antioxidant, radical scavenging, anti-diabetic, anti-Alzheimer's, and anti-inflammatory activities. It was noticed that nobiletin (61) exhibited the highest antioxidant and anti-Alzheimer's activities. At the same time, isorhamnetin 3-O-glucose (51)  showed the highest anti-diabetic activity compared to the other isolated flavonoids and the total extract itself. Regarding the anti-inflammatory activity, no obvious differences were detected numerically among all studied flavonoids.

Phytochemical investigation and spectral characterization of isolated compounds from Pyracantha crenulata (D. Don) M. Roem (syn. Crataegus crenulata Roxb) leaves: evaluation of antioxidant activity and molecular docking analysis.

Pyracantha crenulata (D. Don) M. Roem (syn. Crataegus crenulata Roxb.) is an evergreen shrub in the Rosaceae family, notable for its chemical diversity and biological potential. This study isolates and characterises six compounds (Cc-1 to Cc-6), including four new ones, using repeated column chromatography. Structural elucidation employed IR, UV-vis, 1H and 13 C NMR, and mass spectrometry. The DPPH assay was used to test the antioxidant activity in vitro. Compounds Cc-4, Cc-2, Cc-1, and Cc-5 had IC50 values of 15.734 µg/ml, 51.422 µg/ml, 62.864 µg/ml, and 71.622 µg/ml, in that order. Quantitative phytochemical analysis revealed flavonoid content (22.81 mg/g), tannin content (385.15 mg/g), and total phenolic content (128.78 mg/g). Human cyclin-dependent kinase 2 (CDK2) (PDB ID: 1hck) docked with compound Cc-4, which demonstrated strong antioxidant activity and revealed significant non-bonding interactions. The pkCSM and SwissADME analyses suggested promising drug-like properties for Cc-4, supported by BOILED-Egg diagrams highlighting its therapeutic potential.

Spatial variability in residence time of Beryllium in the Indian Ocean.

Residence time of an element in the ocean is a consequence of its chemical behaviour and the various biogeochemical processes governing its distribution, sources, and sinks. Precise estimation of the residence time of beryllium(Be) is necessary for its application as a tracer for understanding present and paleo-environmental processes. We utilise cosmogenic 10Be and terrestrially derived 9Be measurements from surface sediments to estimate the residence time of Be in the Indian Ocean. Significant variation in Be residence time is observed, which ranges between 370 and 620 years in the central Indian Ocean, 64-205 years in the Bay of Bengal, 41-117 years in the Andaman Sea, and 179-443 years in the Arabian Sea. Large heterogeneity in the residence time of Be can be attributed to its variable scavenging efficiency in different regions. Active scavenging of Be by sediment particles contributed through various major rivers draining into the northern Indian Ocean results in short residence time of Be. The results of this study have significant implications for the selection of sample sites and the use of Be as a tracer in paleo reconstructions.

Effect of alantolactones on cardiac parameters of animals under artificially induced oxidative stress.

Purpose: Phytochemicals have been found effective in reducing the oxidative stress and damage to cardiovascular and other tissues. In this study, the effects of alantolactone (AL) on cardiac parameters in rabbits exposed to artificially-induced oxidative stress were investigated. Method: The oxidative stress was induced in a group of White New Zealand rabbits by injecting 40% hydrogen peroxide solution (1 ml/kg body weight) thrice with an interval of 72 h. The hydrogen peroxide-treated animals were orally treated with AL extracted from the roots of Inula helenium (1 ml/kg repeated thrice after 72 h). Blood samples were taken before and after the hydrogen peroxide and AL treatments, and the sera were subjected to analysis of oxidative damage in terms of malondialdehyde content (MDA), total antioxidant activity (TAOA), linoleic acid reduction capacity (LARC), hydroxyl radical scavenging capacity (HRSC), 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity (DPPH RSC), superoxide dismutase activity (SOD) and catalase activity, and cardiac parameters including troponin-I content (Trop-I), creatine kinase-MB (CKMB), aspartate transaminase (AST). Results: The hydrogen peroxide treatment substantially enhanced MDA content and SOD activity and decreased LARC, HRSC, DPPH, and catalase activity. The AL treatment significantly decreased MDA content, TAOA, Trop-I, CK-MB, and AST levels and increased LARC, DPPH RSC, HRSC, and catalase activity. Conclusion: The observed effect of AL treatment on the animals' oxidative stress, antioxidant status, and cardiac biomarkers emphasizes that AL may effectively manage oxidative stress and cardiac damage.

Drought and heat stress interactions modify photorespiration and hydrogen peroxide content in Silver fir.

Photorespiration (PR) greatly reduces net carbon assimilation in trees (by c. 25%), but has received recent attention particular for its potential role in stress-signaling through the accumulation of hydrogen peroxide (H2O2), a stress signaling agent. Despite an increasing frequency of drought and heat events affecting forests worldwide, little is known about how concurrent abiotic stressors may interact to affect PR and subsequent H2O2 accumulation in trees. Here, we sought to identify how drought and a compounded one-day heat treatment individually and interactively affect PR (determined under variable O2) in Abies alba Mill. seedlings. Additionally, we quantified foliar H2O2 accumulation and enzymatic scavenging via peroxidase in relation to PR rates. We found drought stress to slightly increase PR (+5.2%) during mild-drought (12 days, Ψmd = -0.85 MPa), but ultimately to decrease PR (-13.6%) during severe-drought (26 days, Ψmd = -1.70 MPa) compared to the control, corresponding to increasing non-stomatal limitations of photosynthesis (i.e., decreased electron transport rate). The response of PR to heat stress was dependent on soil water availability as heat stress increased PR in control seedlings (+37.8%), but not in drought-stressed seedlings. Decreased PR during severe-drought corresponded to ~2x lower foliar H2O2 compared to the control. Despite increased PR under heat stress in control seedlings, foliar H2O2 decreased to near-zero likely due to enhanced scavenging as observed in ~2x greater peroxidase activity. Our results demonstrate that carbon loss to PR during drought stress can be highly dynamic, depending on the severity of soil dehydration. Additionally, increased PR under abiotic stress does not necessarily lead to accumulated H2O2, as tight regulation by scavenging enzymes instead minimize oxidative stress, reducing stress-signaling potential.

The role of processing on phenolic bioaccessibility and antioxidant capacity of apple derivatives.

Fruit derivatives are commonly obtained by applying processing operations deemed responsible for the loss of phenol compounds, but very little information is available on the fate of phenols upon digestion of these products. The present study evaluated the effect of thermal and mechanical treatments, commonly applied to turn apple pulp into puree and homogenate, on phenolic bioaccessibility and antioxidant activity. Despite a 20 % decrease in polyphenols due to processing, their bioaccessibility was higher in apple derivatives (>20 %) compared to pulp (∼2 %). Polyphenol oxidase (PPO), inactivated by thermal treatments in apple derivatives but not in the pulp, was hypothesized to be responsible for this difference. Results acquired on an unprocessed PPO-free apple model, only featuring quercetin-3-glucoside and pectin, actually exhibited similar bioaccessibility as processed derivatives. The radical scavenging capacity was unaffected by the structural integrity of apples, indicating independence from the plant tissue's hierarchical arrangement. After digestion, radical scavenging capacity decreased in the real apple matrices, correlating with phenolic content, while it was retained in the apple model, further suggesting the pivotal food matrix role in modulating polyphenols bioaccessibility and subsequent biological activity. Translating these results to an industrial scale, processing conditions can be optimized not only to guarantee that the quality requirements are met, but also to achieve desired nutritional benefits.

Computational Insights into the Radical Scavenging Activity and Xanthine Oxidase Inhibition of the Five Anthocyanins Derived from Grape Skin.

Anthocyanins, typical polyphenol compounds in grape skin, have attracted increasing interest due to their health-promoting properties. In this body of work, five representative anthocyanins (Cy-3-O-glc, Dp-3-O-glc, Pn-3-O-glc, Mv-3-O-glc, and Pt-3-O-glc) were studied using the density functional theory (DFT) to elucidate structure-radical scavenging activity in the relationship and the reaction path underlying the radical-trapping process. Based on thermodynamic parameters involved in HAT, SET-PT, and SPLET mechanisms, along with the structural attributes, it was found that the C4' hydroxyl group mainly contributes to the radical scavenging activities of the investigated compounds. Pt-3-O-glc exhibits a good antioxidant capacity among the five compounds. The preferred radical scavenging mechanisms vary in different phases. For the Pt-3-O-glc compound, the calculations indicate the thermodynamically favoured product is benzodioxole, rather than o-quinone, displaying considerably reduced energy in double HAT mechanisms. Additionally, the thermodynamic and kinetic calculations indicate that the reaction of •OH into the 4'-OH site of Pt-3-O-glc has a lower energy barrier (7.6 kcal/mol), a higher rate constant (5.72 × 109 M-1 s-1), and exhibits potent •OH radical scavenging properties. Molecular docking results have shown the strong affinity of the studied anthocyanins with the pro-oxidant enzyme xanthine oxidase, displaying their significant role in inhibiting ROS formation.

Efficacy of an Innovative Poly-Component Formulation in Counteracting Human Dermal Fibroblast Aging by Influencing Oxidative and Inflammatory Pathways.

Skin aging is characterized by reactive oxygen species (ROS) accumulation, principal players in triggering events associated with aging. Our recent data on the ability of an innovative poly-component formulation (KARISMA Rh Collagen® FACE: K formulation) to suppress the biomolecular events associated with oxidative stress-induced aging prompted us to deepen the mechanisms underlying the observed effects on aged human dermal fibroblasts (HDFs). Here, we evaluated K's ability to perform a direct free radical-scavenging action and modulate anti-oxidant systems by counteracting the inflammatory process in an H2O2-induced cellular senescence model. Standard methods were used to measure scavenging capacity and enzymatic anti-oxidant system activities. Nuclear factor E2-related factor 2 (Nrf2) and nuclear factor kappa-B (NF-κB) levels were analyzed by Western blot. We assessed pro-inflammatory cytokines, matrix metalloproteinases (MMPs), and advanced glycation end-products (AGEs). Our results show that K counteracted stress-induced aging in a dose-dependent manner by exerting a direct scavenging action and increasing anti-oxidant systems, such as superoxide dismutase (SOD) and catalase (CAT) up to control values. These findings could be associated with increased phospho-Nrf2 (p-Nrf2) expression, generally reduced in aged HDFs following exposure to different concentrations of K formulation. Moreover, K formulation caused a reduction of pro-inflammatory cytokines, interleukin-1ß and -6, MMP-1 and -9, and AGE levels, events related to a downregulation of p-NF-κB level. The results indicate that K formulation re-established the normal physiology of HDFs by reducing p-NF-κB expression and restoring Nrf2 activation, thus supporting its efficacious reparative and regenerative action in treating skin aging.

The ABA/LANCL1-2 Hormone/Receptors System Controls ROS Production in Cardiomyocytes through ERRα.

Rat H9c2 cardiomyocytes overexpressing the abscisic acid (ABA) hormone receptors LANCL1 and LANCL2 have an increased mitochondrial proton gradient, respiration, and vitality after hypoxia/reoxygenation. Our aim was to investigate the role of the ABA/LANCL1-2 system in ROS turnover in H9c2 cells. H9c2 cells were retrovirally infected to induce the overexpression or silencing of LANCL1 and LANCL2, without or with the concomitant silencing of the transcription factor ERRα. Enzymes involved in radical production or scavenging were studied by qRT-PCR and Western blot. The mitochondrial proton gradient and ROS were measured with specific fluorescent probes. ROS-generating enzymes decreased, ROS-scavenging enzymes increased, and mitochondrial ROS were reduced in LANCL1/2-overexpressing vs. control cells infected with the empty vector, while the opposite occurred in LANCL1/2-silenced cells. The knockdown of ERRα abrogated all beneficial effects on ROS turnover in LANCL1/2 overexpressing cells. Taken together, these results indicate that the ABA/LANCL1-2 system controls ROS turnover in H9c2 via ERRα. The ABA/LANCL system emerges as a promising target to improve cardiomyocyte mitochondrial function and resilience to oxidative stress.

pH-Dependent Extraction of Antioxidant Peptides from Red Seaweed Palmaria palmata: A Sequential Approach.

This study employed a diverse approach to extract antioxidant peptides from red seaweed Palmaria palmata, recognized for its comparatively high protein content. Initially, an aqueous extraction of the entire seaweed was performed, followed by enzymatic hydrolysis of the solid residues prepared from the first step. The effects of three different pH levels (3, 6, and 9) during the aqueous extraction were also examined. Results indicated that the solid fraction from the sequential extraction process contained significantly higher levels of proteins and amino acids than other fractions (p < 0.05). Furthermore, the solid fractions (IC50 ranging from 2.29 to 8.15 mg.mL-1) demonstrated significantly greater free radical scavengers than the liquid fractions (IC50 ranging from 9.03 to 10.41 mg.mL-1 or not obtained at the highest concentration tested) at both stages of extraction (p < 0.05). Among the solid fractions, those produced fractions under alkaline conditions were less effective in radical scavenging than the produced fractions under acidic or neutral conditions. The fractions with most effective metal ion chelating activity were the solid fractions from the enzymatic stage, particularly at pH 3 (IC50 = 0.63 ± 0.04 mg.mL-1) and pH 6 (IC50 = 0.89 ± 0.07 mg.mL-1), which were significantly more effective than those from the initial extraction stage (p < 0.05). Despite no significant difference in the total phenolic content between these solid fractions and their corresponding liquid fractions (3.79 ± 0.05 vs. 3.48 ± 0.02 mg.mL-1 at pH 3 and 2.43 ± 0.22 vs. 2.51 ± 0.00 mg.mL-1 at pH 6) (p > 0.05), the observed antioxidant properties may be attributed to bioactive amino acids such as histidine, glutamic acid, aspartic acid, tyrosine, and methionine, either as free amino acids or within proteins and peptides.

Assessment of antioxidant properties in selected pigmented and non-pigmented rice (Oryza sativa L.) germplasm and determination of its association with Rc gene haplotypes.

BACKGROUND: Antioxidant properties of rice provide various health benefits due to its ability to inhibit cellular oxidation. Antioxidant content of rice is known to be linked with the pericarp pigmentation. The Rc gene of rice (Os07g0211500) codes for a basic helix-loop-helix (bHLH) protein, acting as a transcriptional factor in regulating proanthocyanidin biosynthesis. The current study was carried out to evaluate the variation of antioxidant properties in a selected panel of rice accessions and assess the possibility of using haplotypes defined based on the Rc gene to predict pericarp pigmentation and antioxidant content in rice. RESULTS: Thirty-two rice accessions were evaluated for grain pericarp colour and antioxidant properties; total phenolic content (TPC), total flavonoids (TFC), proanthocyanidins (PAC) and radical scavenging activity (RSA). The parameters TPC, TFC and PAC showed significant positive correlation with RSA (r > 0.69; P < 0.01). The study panel showed a wide variation for antioxidant properties and rice accessions such as Sudu Heenati, Deweraddiri, Madathawalu, Masuran, Ld 368, At 311, Kalu Heenati, Bw 272-6B, Pokkali, At 362 and Wanni Dahanala exhibited profound potential with respect to antioxidant properties. Based on three-target sites previously reported as critical for the function of the coded bHLH protein (an A/C SNP at 1,353-bp, a 1-bp insertion/deletion at 1,388-bp, and a 14-bp insertion/deletion at 1,408-1,421-bp positioned in the mRNA corresponding to the exon 6 of rice Rc gene), three haplotypes were defined (H1-H3). Pigmentation of the rice pericarp could be successfully explained based on the defined haplotypes (H1 (C/G/+): red, and H2 (A/G/+) and H3 (C/G/-): white), and the H1 haplotype corresponded to a significantly (P < 0.05) higher TPC, TFC, PAC and RSA compared to the other haplotypes. CONCLUSIONS: The studied rice accessions showed a significant variation with respect to antioxidant properties. Haplotype H1 defined based on the three-target sites in the exon 6 of Rc gene can detect rice accessions with red pigmented pericarp and high antioxidant properties effectively. Hence, its use can be recommended as an alternative to biochemical assays for screening during rice breeding programs.

Therapeutics for sickle cell disease intravascular hemolysis.

Sickle cell disease (SCD) is a genetic disorder predominantly affecting individuals of African descent, with a significant global health burden. SCD is characterized by intravascular hemolysis, driven by the polymerization of mutated hemoglobin within red blood cells (RBCs), leading to vascular inflammation, organ damage, and heme toxicity. Clinical manifestations include acute pain crises, hemolytic anemia, and multi-organ dysfunction, imposing substantial morbidity and mortality challenges. Current therapeutic strategies mitigate these complications by increasing the concentration of RBCs with normal hemoglobin via transfusion, inducing fetal hemoglobin, restoring nitric oxide signaling, inhibiting platelet-endothelium interaction, and stabilizing hemoglobin in its oxygenated state. While hydroxyurea and gene therapies show promise, each faces distinct challenges. Hydroxyurea's efficacy varies among patients, and gene therapies, though effective, are limited by issues of accessibility and affordability. An emerging frontier in SCD management involves harnessing endogenous clearance mechanisms for hemolysis products. A recent work by Heggland et al. showed that CD-36-like proteins mediate heme absorption in hematophagous ectoparasite, a type of parasite that feeds on the blood of its host. This discovery underscores the need for further investigation into scavenger receptors (e.g., CD36, SR-BI, SR-BII) for their possible role in heme uptake and detoxification in mammalian species. In this review, we discussed current SCD therapeutics and the specific stages of pathophysiology they target. We identified the limitations of existing treatments and explored potential future developments for novel SCD therapies. Novel therapeutic targets, including heme scavenging pathways, hold the potential for improving outcomes and reducing the global burden of SCD.

Antioxidant Properties and Vasorelaxant Mechanism of Aqueous Extract of Ricinodendron heudelotii (Euphorbiaceae).

Ricinodendron heudelotii is a plant of the Euphorbiaceae family, used in traditional medicine to treat numerous diseases, including high blood pressure. The aim of this study is to evaluate the antioxidant and vasorelaxant effects of the aqueous extract of the stem bark of R. heudelotii. The pharmacological studies were carried out using the aqueous extract obtained by infusion. The antioxidant capacity of R. heudelotii was assessed by in vitro tests with DPPH (2,2-diphenyl-1-picryl-hydrazyl), ABTS (2,2'-azino-bis (3-ethylbenz-thiazoline-6-sulfonic acid), iron-reducing capacity (FRAP), and inhibition of nitric oxide (NO) release. In vitro studies, the aortic rings obtained from adult Wistar albino rats of both sexes were used to determine the vasorelaxant effects of the extract of R. heudelotii on the NO and prostacyclin (PGI2) pathways as well as its involvement on various potassium channels were determined on intact or naked fragments of rat aorta precontracted with phenylephrine (10-6 M) or KCl (60 mM). The aqueous extract of R. heudelotii exhibited a remarkable DPPH (EC50: 1.68 µg/mL) and ABTS (EC50: 106.30 µg/mL) and nitric oxide (53.71% inhibition at 1000 µg/mL) radical scavenging activities as well as reducing power (absorbance of 1.56 at 1000 µg/mL). The nitric oxide inhibitor, NG-nitro-L-arginine methyl ester (L-NAME), and prostacyclin inhibitor, indomethacin, significantly attenuated the vasodilatory effect of R. heudelotii. Tetraethylammonium could not inhibit the vasodilatory effect of the extract, unlike glibenclamide and barium chloride. Ricinodendron heudelotii extract possesses antioxidant properties and vasorelaxing effect linked to endothelium-related factors, and this relaxation was partially mediated mainly through the inhibition of Kir and KATP channels.