Cellular Antioxidant Activity Research Articles

Stability, bioavailability, and cellular antioxidant activity of piperine complexed with cyclic glucans

Abstract Piperine, the primary bioactive compound in black pepper, was complexed with cyclic glucans, including cycloamylose (CA), α-cyclodextrin, and 2-hydroxypropyl-β-cyclodextrin, to investigate the complexation effects on its solubility, stability, bioavailability, and cellular antioxidant activity (CAA). The formation of inclusion complex (IC) significantly improved the phase solubility of piperine and enhanced its stability under ultraviolet light, heat, and acidic conditions. Additionally, IC increased the retention rate of piperine after in vitro digestion. Permeability analysis using a Caco-2 cell monolayer showed that IC samples, particularly CAIC, reduced the efflux ratio compared to free piperine by decreasing the apparent permeability coefficient from apical-to-basolateral (Papp (B-A)). Moreover, the enhanced cellular uptake capacity of piperine in IC contributed to a marked improvement in its CAA, CAIC showing the most pronounced effect. Therefore, inclusion complexation with cyclic glucans, especially CA, can be a practical strategy to overcome the lower solubility and bioavailability of free piperine in various industrial applications.

Selenoprotein K Confers Protection against Iron Dyshomeostasis-Related Neurotoxicity by Regulating the Palmitoylation of TfR-1.

Selenoprotein K (SELENOK), a protein residing in the endoplasmic reticulum (ER), is modulated by dietary selenium and is expressed at elevated levels in neurons. SELENOK has been shown to participate in cellular antioxidant activity and posttranslational palmitoylation. This study presents both in vivo and in vitro evidence that SELENOK deficiency reduces the palmitoylation of TfR-1, thereby impairing transferrin transport and ultimately leading to a decrease in the intracellular iron content, impaired mitochondrial respiratory chain activity and decreased ATP production. Remarkably, restoring SELENOK levels significantly enhanced TfR-1 palmitoylation, increased intracellular iron levels, and restored mitochondrial function, thus ameliorating cognitive deficits in 7 month-old SELENOK knockout mice. Consistent with these findings, iron supplementation also improved mitochondrial function by elevating intracellular iron levels, thereby improving cognitive deficits in 7 month-old SELENOK knockout mice. Therefore, SELENOK exerts its neuroprotective effect by regulating the palmitoylation of TfR-1 to maintain iron homeostasis, thereby protecting mitochondrial function in neurons.

Gross Antioxidant Capacity and Anti-Inflammatory Potential of Flavonol Oxidation Products: A Combined Experimental and Theoretical Study.

This study evaluated the antioxidant capacity of the oxidation products of three flavonols using oxygen radical absorbance capacity-fluorescein assay (ORAC-FL), oxygen radical absorbance capacity-pyrogallol red assay (ORAC-PGR), and the cellular antioxidant activity (CAA) assay in human dermal fibroblast (HFF) cells, with 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) as a free radical generator under controlled pH and solvent conditions. At pH 2 in a polar aprotic solvent, BZF-OH (benzofuranone-OH) compounds were formed, while methoxylated analogs were obtained at pH 7 in a polar protic solvent. The products generated at pH 2 exhibited significantly higher antioxidant capacities, demonstrating the influence of the reaction environment on modulating antioxidant properties. The antioxidant activity was observed to reflect the combined action of the flavonol precursor and its oxidation products. This led to the proposal of the Gross Antioxidant Capacity (GAC) concept to integrate the contribution of all generated species. Since chemical assays such as ORAC do not fully capture the complexity of biological systems, they should be complemented with cellular approaches for a more accurate evaluation. Additionally, BZF-OH compounds were analyzed as potential cyclooxygenase-2 (COX-2) inhibitors through docking and molecular dynamics simulations, where BZF-Quer-OH showed binding affinities comparable to celecoxib, a selective COX-2 inhibitor. These findings were complemented by an analysis of COX-2 expression in RAW 264.7 cells treated with lipopolysaccharide (LPS), where treatment with the antioxidants significantly inhibited COX-2 expression. In the case of the oxidation products, only the oxidation product of rhamnetin showed a reduction in COX-2 expression compared to the LPS-treated control. Together, these results highlight that flavonol-derived oxidation products not only retain significant antioxidant capacity but may also possess anti-inflammatory properties, opening new perspectives for the development of innovative therapies targeting oxidative stress and chronic inflammation.

Optimizing the Methodology for Antioxidant Activity Analysis of Manuka Honey

Manuka honey (MH) is increasingly recognized for its potent antioxidant properties, making it a promising functional food ingredient. However, discrepancies in assessment methods have impeded the standardization of its antioxidant capacity. This study compared DPPH, ABTS, and cellular antioxidant activity (CAA) assays under varying conditions to identify the most reliable approach for assessing MH’s antioxidant properties. The results showed that the reaction temperature for the chemical method, setting it at 37 °C, enhanced the antioxidant capacity of MH. For the cellular assay, we optimized honey concentration, injury duration, damage model, and cell model. The result showed that sugar-reduced MH achieved the same high efficiency as the chemical method. A stable cellular assay method was established in HepG2 cells, offering superior reproducibility with an intra-RSD of 4.83% (<5%) and an inter-RSD of 7.51% (<10%). Additionally, studies have found that methyl syringate (MSY), a key polyphenolic compound in Manuka honey (MH), exhibits extremely high antioxidant activity. However, due to its low concentration, its overall contribution to the honey’s antioxidant activity is limited. This optimized CAA-based approach provides reliable technical support for the accurate evaluation of the antioxidant activity of MH.

Fluorine-Incorporated Biogenic Hydroxyapatite Enhances Socket Bone Healing via Addressing Macrophage-Mediated Inflammatory Response

Biological hydroxyapatite (BHA) has been extensively employed in alveolar socket preservation, yet its clinical application is often compromised by delayed bone healing triggered by macrophage-mediated pro-inflammatory responses. Building upon our previous work, in which we successfully incorporated fluorine into BHA to develop fluorinated biogenic hydroxyapatite (FBHA) with superior physicochemical and biological properties, this study systematically investigated the effects of fluorine doping on macrophage-mediated osteoimmunomodulation and socket bone healing. The synthesized FBHA was characterized using SEM, EDS, and fluoride ion release assays to confirm fluorine incorporation. In macrophage co-culture models, FBHA demonstrated significant advantages over BHA, effectively suppressing iNOS and TNFα gene expression, reducing NO release, and inhibiting phagocytic activity in M1 macrophages. RNAseq analysis revealed that the M1 phenotype suppression might be mediated through enhanced cellular antioxidant activity. Moreover, in macrophage-conditioned microenvironments, FBHA significantly upregulated osteogenic gene expression and ALP activity of pre-osteoblasts. In vivo experiments demonstrated FBHA’s superior performance in alveolar ridge preservation, especially in new bone formation and mineralization inside sockets. Fluorine doping significantly boosted socket bone healing via suppressing the inflammatory response of macrophages and enhancing osteogenic differentiation of pre-osteoblasts. These findings provide valuable insights into the development of next-generation biomaterials for alveolar socket preservation.

Impacts of Resistance Training on Endogenous Antioxidants in Older Individuals: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Cellular antioxidant activity and oxidative stress are assumed to be critical factors in the aging process. This study aims to investigate the effects of resistance training (RT) on endogenous antioxidants in healthy older individuals. The records were identified through searches in 5 electronic databases (PubMed, Bireme, Scopus, SPORTDiscus, and Web of Science) in June 2024 for eligible randomized controlled trials that observed older individuals subjected to RT programs that reported endogenous antioxidant outcomes. The Tool for the assEssment of Study qualiTy and reporting in EXercise (ranging from 0 to 15) was used to verify the methodological quality of the studies. Fourteen randomized controlled trials involving 676 healthy older individuals were included in the systematic review. Of these, 10 articles were included in the meta-analysis. The meta-analysis indicated that RT interventions did not have significant effects on improving catalaselevels (standardized mean difference = 0.84; 95% CI, -0.61 to 2.29) or antioxidant activity (standardized mean difference = 0.28; 95% CI, -0.41 to 0.98). However, RT was associated with a significant reduction in superoxide dismutase (mean difference = -0.16; 95% CI, -0.29 to -0.04) and glutathione peroxidase increased (standardized mean difference = 0.57; 95% CI, 0.13 to 1.01). Based on available evidence, the meta-analysis suggests potential improvement in glutathione peroxidase gene expression and reduction in gene expression of superoxide dismutase after the intervention physical activity interventionin healthy older individuals.

Turning agro-food waste into resources: Exploring the antioxidant effects of bioactive compounds bioaccessibility from digested jabuticaba tree leaf extract.

Turning agro-food waste into resources: Exploring the antioxidant effects of bioactive compounds bioaccessibility from digested jabuticaba tree leaf extract.

The protective effects of melatonin against electromagnetic waves of cell phones in animal models: A systematic review.

Due to the widespread use of cell phone devices today, numerous research studies have focused on the adverse effects of electromagnetic radiation on human neuropsychological and reproductive systems. In most studies, oxidative stress has been identified as the primary pathophysiological mechanism underlying the harmful effects of electromagnetic waves. This paper aims to provide a holistic review of the protective effects of melatonin against cell phone-induced electromagnetic waves on various organs. This study is a systematic review of articles chosen by searching Google Scholar, PubMed, Embase, Scopus, Web of Science, and Science Direct using the keywords 'melatonin', 'cell phone radiation', and 'animal model'. The search focused on articles written in English, which were reviewed and evaluated. The PRISMA process was used to review the articles chosen for the study, and the JBI checklist was used to check the quality of the reviewed articles. In the final review of 11 valid quality-checked articles, the effects of melatonin in the intervention group, the effects of electromagnetic waves in the case group, and the amount of melatonin in the chosen organ, i.e. brain, skin, eyes, testis and the kidney were thoroughly examined. The review showed that electromagnetic waves increase cellular anti-oxidative activity in different tissues such as the brain, the skin, the eyes, the testis, and the kidneys. Melatonin can considerably augment the anti-oxidative system of cells and protect tissues; these measurements were significantly increased in control groups. Electromagnetic waves can induce tissue atrophy and cell death in various organs including the brain and the skin and this effect was highly decreased by melatonin. Our review confirms that melatonin effectively protects the organs of animal models against electromagnetic waves. In light of this conclusion and the current world-wide use of melatonin, future studies should advance to the stages of human clinical trials. We also recommend that more research in the field of melatonin physiology is conducted in order to protect exposed cells from dying and that melatonin should be considered as a pharmaceutical option for treating the complications resulting from electromagnetic waves in humans.

Optimization of Supercritical Fluid Extraction for the Recovery of γ-Oryzanol-Rich Extracts with Improved Bioactivity from Rice Bran.

Rice bran (RB) is a rice processing by-product recognized to be a source of bioactive compounds, including γ-oryzanol and fatty acids, which have interesting bioactivities such as antioxidant and anti-inflammatory effects. This study aims to optimize the supercritical fluid extraction process for recovering these high-value compounds from rice bran with improved bioactivity. A Central Composite Face-Centered Design was employed to optimize the extraction process by varying the temperature (40-80 °C) and pressure (200-500 bar). The optimal extraction conditions were identified at 500 bar and 62 °C that led to the extraction of 17.3% mass yield with 784.5 mg of fatty acids and 36.6 mg of γ-oryzanol per gram of extract, striking a balance between extraction yield and bioactive concentrations. When compared with conventional extractions with n-hexane, supercritical fluid extraction showed similar global yield (18.0 vs. 17.3%) and FA concentration (130.14 vs. 135.70 mg/g of RB) but higher selectivity and extraction yield for γ-oryzanol (18.0 vs. 36.4 mg/g extract; 3.3 vs. 6.3 mg/g of RB). Cellular antioxidant activity assays showed that both extracts reduced the quantity of reactive oxygen species (ROS) up to 50% in Caco-2 cells submitted to oxidative stress. Importantly, supercritical fluid extract was more effective in inhibiting colorectal cancer cell growth (EC50 = 0.9 mg/mL vs. 1.15 mg/mL) than the hexane extract, and this effect was more pronounced than that obtained for pure γ-oryzanol in the same concentration range. These findings highlight the potential of supercritical fluid technology to develop rice bran extracts with antioxidant and antiproliferative properties, underlining the promising applications of this technology in the field of natural product extraction.

Amniotic fluid stem cell conditioned medium's role in Schwann cell proliferation, survival, and cellular antioxidant activity under normative and oxidative stress conditions.

Peripheral nerve injuries present a major clinical challenge due to their high morbidity and often incomplete recovery of function. While autografts remain the gold standard for nerve repair, their use is constrained by limited donor availability and donor site complications. Alternative strategies, such as allografts and tissue-engineered grafts, have been developed but are still associated with suboptimal outcomes, including chronic pain and sensory disturbances. Thus, there is a need for novel therapies that can enhance nerve regeneration. Amniotic fluid stem cell conditioned medium (AFS-CM) houses regenerative properties that may be useful in peripheral nerve injury. This study aims to assess the role of AFS-CM on Schwann cell survival and proliferation under normative and oxidative stress conditions, preventing oxidative stress-induced premature senescence of Schwann cells in vitro and maintaining cellular redox homeostasis. Primary Schwann cells were treated with various concentrations of AFS-CM. Cell proliferation was assessed using the Cell Counting Kit-8 (CCK-8) assay, and viability under oxidative stress was measured after exposing cells to hydrogen peroxide (H2O2). Reactive oxygen species (ROS) levels and both catalase and superoxide dismutase (SOD) levels were evaluated. Cellular senescence markers were also assessed to determine AFS-CM's protective effects. AFS-CM treatment resulted in a dose-dependent increase in Schwann cell proliferation (P<0.05). Under oxidative stress conditions, AFS-CM significantly improved cell viability compared to controls (P<0.05). ROS levels were markedly reduced in AFS-CM-treated cells (P<0.05), and this was accompanied by upregulation of catalase and SOD expression (P<0.05). Moreover, AFS-CM reduced stress-induced cellular senescence, as indicated by decreased senescence-associated β-galactosidase activity and lower expression of senescence markers (P<0.05). AFS-CM enhances Schwann cell proliferation, viability, and resistance to oxidative stress, while reducing cellular senescence. These findings suggest that AFS-CM could be a promising adjunctive therapy for peripheral nerve injuries by promoting Schwann cell resilience and regenerative capacity. Future studies are needed to validate these in vitro results in vivo and explore their potential clinical application for improving functional recovery in patients with peripheral nerve damage.

Exogenous application of chemical elicitors affects crop yield and nutraceutical potential of yellow summer squash (Cucurbita pepo L. var. cylindrica) fruits

ABSTRACT The aim of this study was to evaluate the effects of applying chitosan (CHT), methyl jasmonate (MeJA), and salicylic acid (SA) during cultivation of yellow summer squash on selected nutraceutical properties. Plants treated with SA (3 mM) increased the number of fruits, fruit weight, and crop yield by 91.6, 51.4, and 188.8%, respectively (p ≤ 0.05). SA (3 mM) and MeJA (1.5 mM) increased the total phenolic content (TPC) by 19.3 and 39.8%, respectively. SA (3 mM) also increased total flavonoid content (TF) by 28.2% and the antioxidant capacity (AC) by 15.5–60.5%. The three elicitors CHT (1.5 g/L), MeJA (1.5 mM) and SA (3 mM) increased (13.3–17.4%) the cellular antioxidant activity (CCA) compared to the control. Among the treatments, SA (3 mM) was the most effective in enhancing crop yield and key nutraceutical properties while preserving postharvest quality. Although pronounced, CHT (1.5 g/L) and MeJA (1.5 mM) also contributed to crop yield, TPC, and CAA, underscoring their potential as complementary strategies to optimise the production and quality of yellow summer squash.

Exploring the role of curcumin in mitigating oxidative stress to alleviate lipid metabolism disorders.

Lipid metabolism plays a crucial role in maintaining homeostasis and overall health, as lipids are essential molecules involved in bioenergetic processes. An increasing body of research indicates that disorders of lipid metabolism can contribute to the development and progression of various diseases, including hyperlipidemia, obesity, non-alcoholic fatty liver disease (NAFLD), diabetes mellitus, atherosclerosis, and cancer, potentially leading to poor prognoses. The activation of the oxidative stress pathway disrupts lipid metabolism and induces cellular stress, significantly contributing to metabolic disorders. A well-documented crosstalk and interconnection between these metabolic disorders exists. Consequently, researchers have sought to identify antioxidant-rich substances in readily accessible everyday foods for potential use as complementary therapies. Curcumin, known for its anti-inflammatory and antioxidant properties, has been shown to enhance cellular antioxidant activity, mitigate oxidative stress, and alleviate lipid metabolism disorders by reducing reactive oxygen species (ROS) accumulation. These effects include decreasing fat deposition, increasing fatty acid uptake, and improving insulin sensitivity. A review of the existing literature reveals numerous studies emphasizing the role of curcumin in the prevention and management of metabolic diseases. Curcumin influences metabolic disorders through multiple mechanisms of action, with the oxidative stress pathway playing a central role in various lipid metabolism disorders. Thus, we aimed to elucidate the role of curcumin in various metabolic disorders through a unified mechanism of action, offering new insights into the prevention and treatment of metabolic diseases. Firstly, this article provides a brief overview of the basic pathophysiological processes of oxidative stress and lipid metabolism, as well as the role of oxidative stress in the pathogenesis of lipid metabolism disorders. Notably, the article reviews the role of curcumin in mitigating oxidative stress and in preventing and treating diseases associated with lipid metabolism disorders, including hyperlipidemia, non-alcoholic fatty liver disease (NAFLD), atherosclerosis, obesity, and diabetes, thereby highlighting the therapeutic potential of curcumin in lipid metabolism-related diseases.

Construction of chitosan hydrochloride-carboxymethyl chitosan nanoparticles using anti-solvent method for the co-delivery of puerarin and resveratrol.

The applications of resveratrol (RES) and puerarin (PUE) with notable physiological functions are greatly limited in functional food and pharmaceutical industries due to their poor water solubility and chemical instability. Accordingly, co-loading of RES and PUE into chitosan-based nanoparticles (NPs) is performed here by an anti-solvent method to improve their bioavailability. The fabricated NPs at 8:1 mass ratio of carboxymethyl chitosan (CMC) to chitosan hydrochloride (CHC) with the particle size of 375.1nm and zeta potential of +36.5mV showed encouraging encapsulation efficiency and loading capacity at 85.2% (RES), 89.5% (PUE), and 15.5%. The microstructure of core-shell CMC-CHC was confirmed through dynamic light scattering and transmission electron microscopy. Molecular docking and storage stability indicating the more beneficial encapsulation of chitosan derivatives to PUE in comparison to RES. Cellular antioxidant activity experiments showed that the bioactivities of PUE/RES after loading with 20 and 40mg·mL-1 were improved by 13.2% and 18.5%, respectively, with respect to free ones. Therefore, RES/PUE-loaded CHC-CMC NPs were successfully prepared in this study, thus significantly improving the RES and PUE bioavailability and promoting their applications in functional food and pharmaceutical industries.

Chemometric Classification and Bioactivity Correlation of Black Instant Coffee and Coffee Bean Extract by Chlorogenic Acid Profiling.

Chlorogenic acids (CGAs) play a key role in defining the quality and functionality of coffee products. CGA fingerprints of black instant coffee (BIC) and coffee bean extract (CBE) were profiled using ultra-performance liquid chromatography-mass spectrometry and analyzed by chemometrics. A total of 25 CGAs were identified. The BICs yielded higher levels of major CGAs than the CBEs. Furthermore, chemometrics methods, including principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA), successfully classified the CBEs and the BICs. In vitro cellular antioxidant activity and viability assays between coffee products further confirmed the relationship between phenolic compounds and bioactivities. Compared to the CBEs, the BICs provided higher cellular toxicity and oxidant activity for hepatocellular carcinoma G2 (HepG2) cells. These results demonstrated that CGAs and their derivatives could be markers for studying coffee-related products. This study revealed the unique phenolic profiles of various coffee products, highlighting the differences between whole beans and soluble coffee.

Tailored recovery of antioxidant fractions enriched in caffeine and phenolic compounds from coffee pulp using ethanol-modified supercritical carbon dioxide

Tailored recovery of antioxidant fractions enriched in caffeine and phenolic compounds from coffee pulp using ethanol-modified supercritical carbon dioxide

Extracts from Tartary Buckwheat Sprouts Restricts Oxidative Injury Induced by Hydrogen Peroxide in HepG2 by Upregulating the Redox System.

Oxidative stress, which results from an overproduction of reactive oxygen species (ROS), can cause damage that may contribute to a range of metabolic disorders. Antioxidants are considered to upregulate the activity of antioxidant enzymes, which are crucial for eliminating excess ROS and safeguarding the body against oxidative stress-induced damage. In the present study, the effect of polyphenol extracts from tartary buckwheat sprouts (TBSE) on the redox system of HepG2-cell-induced oxidative injury by hydrogen peroxide were investigated for evaluating the protective effect and mechanism of tartary buckwheat sprouts (TBS). The results revealed that TBSE that had sprouted for a period of 10 days possessed six predominant phenolic compounds, ranked from the most abundant to the least: chlorogenic acid, syringic acid, caffeic acid, rutin, ferulic acid, and quercetin. TBSE could successfully inhibit H2O2-induced ROS overproduction, restore and balance the mitochondrial membrane potential, while also significantly increasing cellular antioxidant activity (CAA) and the expression of protective enzymes such as SOD, CAT, and GST. More interestingly, treating HepG2 cells with TBSE triggered the translocation of Nrf2 to the nucleus, accompanied by a negative feedback mechanism involving Keap1. Therefore, it regulated the downstream production of antioxidant enzymes, including NQO1 and HO-1. Overall, this finding suggested that TBSE could restore the redox state of H2O2-resistant HepG2 cells, indicating TBSE protected cells from H2O2-induced oxidative stress significantly. Beneficial resistance and effects on redox balance were attributed to activation of Nrf2. Present work revealed the potential health benefits of TBS and provided a test basis for developing functional food of TBS.

Pro-oxidant Tetrapleura tetraptera polyphenol extract parallels quercetin as an in vitro cytotoxic agent in human liver cancer cells

Pro-oxidant Tetrapleura tetraptera polyphenol extract parallels quercetin as an in vitro cytotoxic agent in human liver cancer cells

Alpha-lipoic acid, as an effective agent against toxic elements: a review.

This review aims to evaluate the efficacy of alpha-lipoic acid (ALA) in combating toxic elements, such as aluminum, arsenic, lead, mercury, and cadmium. The primary research question addressed is whether ALA can effectively mitigate the toxic effects of these metals through its antioxidant and chelating properties. Articles published between 1995 and 2024 were collected from Scopus, PubMed, Google Scholar, and Web of Science. Using Boolean (AND and OR), English-language publications were selected based on medical subject headings, titles, or abstracts that contained keywords related to ALA, metals, toxicity, antioxidants, and chelation. ALA supplementation significantly enhances cellular defense mechanisms and antioxidant enzyme activity. It effectively mitigates the adverse effects of aluminum exposure, counters arsenic toxicity in various cells and organs, and reduces cadmium toxicity, resulting in lower mortality rates among treated groups. Although ALA acts as a lead chelator, its efficacy is less than standard chelators. In the case of mercury, ALA shows beneficial effects in long-term therapy, although its capacity to reduce mercury concentration is limited. Overall, ALA emerges as a promising alternative for alleviating metal toxicity by enhancing antioxidant defenses, chelating toxic metals, and reversing their harmful effects. Further research in this area is encouraged to explore the full potential of ALA in mitigating the toxic effects of metals on biological systems.

Moringa oleifera Lam. Leaf Peptides: Antioxidant and Antiproliferative Activity in Human Colon Cancer Caco-2 Cell Line.

Reactive oxygen species are produced as part of the cellular metabolism. However, lifestyle can promote an excess in their concentration. Free radicals react with DNA, promoting the appearance of cancer cells. Therefore, natural antioxidants have been suggested as an alternative to prevent this disorder. Peptides are protein fragments that have been produced from various plants. In previous work, Moringa oleifera leaf peptides (MOPHs) with antioxidant potential were generated and identified. However, the spectrophotometric methods used to evaluate their antioxidant activity do not fully reflect its potential. In this work, the antioxidant activity of MOPHs was assessed by the ferric reducing antioxidant power assay (FRAP) and cellular antioxidant activity method on the human colon cancer cell line Caco-2. Also, their antiproliferative activity was evaluated. The MOPHs exhibited a FRAP activity of 1435 µmol TE/g, and at 500 µg/mL; the peptides did not show a cytotoxic effect on healthy colon CCD-18Co cells. Moreover, the MOPHs increased Caco-2 antioxidative activity to a greater extent by 73.45% and 83.62% at 250 and 500 µg/mL, respectively. Regarding cellular proliferation, the MOPHs inhibited it by 78.19% and 90.20% at 200 and 500 µg/mL, respectively. These findings highlight the potential of Moringa oleifera leaf peptides as functional ingredients with significant health benefits, demonstrating antioxidant and antiproliferative properties.

Isolation, Purification, and Antioxidant Activity of Polyphenols from Cynanchum auriculatum Royle ex Wight

Cynanchum auriculatum Royle ex Wight (CA) is a traditional medicinal and edible plant in China. This study aimed to isolate and characterize the phenolic compounds of C. auriculatum to identify its main antioxidant constituents. Polyphenols were extracted using an ultrasound-assisted ethanol extraction method, followed by partitioning with ethyl acetate. The ethyl acetate extract was then purified through thin-layer chromatography, silica gel column chromatography, and reverse-phase silica gel column chromatography. Three monomeric compounds—cynandione A (I), 2,5-dihydroxyacetophenone (II), and radix piperacanthone (III)—were identified through their physical and chemical properties, UV and IR spectra, and liquid chromatography–mass spectrometry (LC-MS/MS). Vitamin C (VC) and 2,4-dihydroxyacetophenone were used as controls to evaluate the antioxidant potential of the two most abundant monomers. Antioxidant assays demonstrated that 2,5-dihydroxyacetophenone and cynandione A exhibited strong antioxidant activity at lower concentrations, whereas 2,4-dihydroxyacetophenone showed significantly weaker activity. Furthermore, cynandione A displayed superior cellular antioxidant activity compared to 2,5-dihydroxyacetophenone, indicating its potential as a promising bioactive compound. In conclusion, this study provides valuable insights into the phenolic composition of C. auriculatum and highlights cynandione A as a key antioxidant, paving the way for future research on its therapeutic applications.