ABTS Free Radical Scavenging Assay Research Articles

Potential Antioxidant Compounds from the Spores of Dicranopteris linearis and the Branches of Averrhoa bilimbi

This study focused on bio-guided isolation based on antioxidant activities from Dicranopteris linearis spores and Averrhoa bilimbi branches. The total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities of the extracts were determined. For D. linearis spores, the ethyl acetate (EA) extract exhibited the highest TPC (120.13 ± 0.04 mg GAE/g) and TFC (21.94 ± 0.30 mg QE/g), along with strong DPPH antioxidant activity (96.3 ± 0.3% inhibition, IC50 of 39.4 ± 0.3 µg/mL). For A. bilimbi branches, the n-hexane–ethyl acetate (HEA) extract showed the highest TPC (165.21 ± 0.24 mg GAE/g) and TFC (26.20 ± 0.01 mg QE/g), with significant DPPH antioxidant activity (89.6 ± 0.7% inhibition, IC50 of 39.7 ± 1.9 µg/mL). Phytochemical investigation led to the identification of ten compounds (D1–D10) from D. linearis spores and twelve compounds (A1–A12) from A. bilimbi branches. Notably, compound A1 was identified as a new natural compound. The chemical structures were elucidated through NMR spectroscopy and comparison with existing literature. The antioxidant activities of selected compounds (D3–D5, D8–D10, and A1–A11) were evaluated using DPPH and ABTS free radical scavenging assays. Among them, compound A3 exhibited the strongest antioxidant activities (IC50 of 7.1 ± 0.1 µg/mL for DPPH and 14.8 ± 0.1 for ABTS, respectively). The results of this study highlight the potential of D. linearis and A. bilimbi for use in natural product-based antioxidant applications.

Comprehensive Evaluation of Quality and Differences in Silene viscidula Franch from Different Origins Based on UPLC-ZENO-Q-TOF-MS/MS Compounds Analysis and Antioxidant Capacity.

Silene viscidula Franch is mainly produced in southwest China. The region has a vast area and rich climate, which has an impact on the quality of the plants due to the differences in distribution between the origins. There is a lack of systematic research on its chemical compounds in the existing literature, and fewer studies have been reported for the active compounds of this plant. Therefore, high-resolution liquid mass spectrometry was used in this study. Sixty batches of Silene viscidula Franch samples from twenty origins in three provinces were analyzed for compounds. A database of chemical compounds of Silene viscidula Franch was established through node-to-node information in the GNPS molecular network, as well as literature records. The ion fragmentation information obtained was compared with the literature data and analyzed and identified by importing the mass spectrometry software PeakView 1.2. Then, the MarkerView t-test was applied to analyze and identify the compounds of Silene viscidula Franch from different origins. Afterwards, the antioxidant activity of Silene viscidula Franch from different origins was preliminarily evaluated using DPPH and ABTS free radical scavenging assays. The results showed a total of 78 compounds, including 34 steroids, 14 triterpenoid saponins, 30 flavonoid glycosides, and other classes of compounds, such as alkaloids. The cleavage patterns of steroids, triterpenoid saponins, and flavonoids in positive-ion mode were also summarized. Based on the p-value of the t-test (p < 0.05), 29 differential compounds were screened out. The relative contents of saponins and steroidal compounds in these samples were found to be associated with antioxidant activity. This study provided a preliminary reference for the establishment of a comprehensive evaluation system for the quality of Silene viscidula Franch.

Research on the Isolation of Endophytic Fungi from Papaya and the Prevention of Colletotrichum gloeosporioides.

Endophytic fungi can be used as a source of herbal antioxidants to overcome the limitations of low yield and lengthy growth cycles associated with using plants as raw materials for antioxidant production. Papaya fruit is often susceptible to infection by Colletotrichum gloeosporioides after harvest, leading to postharvest rot. Endophytic fungi were extracted with ethyl acetate, and the initial screening concentration was 100 mg/L. Seven strains were identified, with scavenging rates exceeding 50% and strong antioxidant activity. The IC50 values in DPPH and ABTS free radical scavenging assays ranged from 19.72 to 84.06 mg/L and from 14.34 to 64.63 mg/L, respectively. Strain Y17 exhibited robust antioxidant activity (IC50 < 20 mg/L) and was identified as Penicillium rolfsii (MT729953) through ITS sequencing. Treatment of papaya fruit wounds with a fermentation broth of strain Y17 significantly inhibited the infection and colonization of anthracnose pathogens, resulting in a slowed disease incidence rate. This promoted the activity of protective enzymes, such as CAT, POD, and SOD, in the papaya fruit and slowed down the rate of MDA accumulation. This strain, which was found to have antioxidant activity in this study, has the potential to control anthracnose in papaya and has value in terms of further development and utilization.

Natural Polysaccharides Derived from Fruits and Mushrooms with Anti-inflammatory and Antioxidant Effects

: A large class of substances known as polysaccharides have a wide range of advantageous therapeutic and nutritional properties. Polysaccharides found in plants and plant components are extracted for the use in treating a number of diseases. Since ancient times, these polysaccharides have been utilized for human wellness. With no or minimal adverse effects, the polysaccharides that were extracted and refined from the fruits exhibit strong antioxidant, antiinflammatory, immunoregulatory, and hepatoprotective action. These fruit polysaccharides are isolated and purified using numerous chromatographic methods. In this review, the polysaccharide obtained from sources such as Rubus chingii, Mulberry, Glycyrrhiza glabra, Lilium davidii, Flammulina velutipes, Angelica sinesis, and Diospyros kaki have been discussed along with their biological activities including DPPH radical scavenging activity, ABTS free radical scavenging assay, Hydroxyl radical scavenging activity and assay for oxygen free radical absorption capacity (ORAC) listed in various studies.

Inhalation of Curcumae Rhizoma volatile oil attenuates depression-like behaviours via activating the Nrf2 pathway to alleviate oxidative stress and improve mitochondrial dysfunction.

Curcumae Rhizoma (CR) is a traditional Chinese medicine used frequently in clinics, which contains volatile components that exhibit various active effects. This study explores the effect of Curcumae Rhizoma volatile oil (CRVO) on depressive mice and its possible mechanism of action. Chemical composition of CRVO was analysed by GC-MS. DPPH and ABTS free radical scavenging assays were used to evaluate the in vitro antioxidant capacity of CRVO. A chronic unpredictable mild stress (CUMS) model was used to evaluate the antidepressant effect of CRVO. The effects of CRVO on oxidative stress in vivo were investigated using Nissl staining, ELISA and transmission electron microscopy. The Nrf2/HO-1/NQO1 signalling pathway was detected by western blotting and immunofluorescence. ML385, a Nrf2 inhibitor was used to validate the effect of Nrf2 on CUMS mice with CRVO treatment. Phytochemical analysis showed that CRVO is rich in its characteristic components, including curzerene (31.1%), curdione (30.56%), and germacrone (12.44%). In vivo, the administration of CRVO significantly ameliorated CUMS-induced depressive-like behaviours. In addition, inhalation of CRVO significantly alleviated the oxidative stress caused by CUMS and improved neuronal damage and mitochondrial dysfunction. The results of mechanistic studies showed that the mechanism of action is related to the Nrf2/HO-1/NQO1 pathway and the antioxidant and antidepressant effects of CRVO were weakened when ML385 was used. In summary, by regulating the Nrf2 pathway, inhalation of CRVO can reduce oxidative stress in depressed mice, thereby reducing neuronal damage and mitochondrial dysfunction to alleviate depression-like behaviours. Our study offers a prospective research foundation to meet the diversity of clinical medication.

Enhanced stability and antibacterial efficacy of edible oleogels-in-water high internal phase emulsions prepared from soybean lipophilic protein

Recently, convenience-driven consumers have increasingly embraced prepared aquatic foods, facilitating a significant shift within the food industry. However, this change has presented a challenge for maintaining the quality of aquatic products in prepared food items since aquatic products are highly susceptible to microbial contamination during processing or storage. Herein, smart oleogels-in-water high internal phase emulsions (GHIPEs) stabilized solely by soybean lipophilic protein (LP) were prepared via oil phase gelation induced by glycerol monolaurate (GML). The purpose of this system is to act as an effective carrier and facilitate the precise release of thyme essential oils to extend the shelf life of food products. The gelation of the oil phase has significantly enhanced the stability of GHIPEs when compared to traditional HIPEs. When the GML reached 2%, the GHIPEs retained up to 87.18% ± 4.23 of thyme essential oil after 14 d. Moreover, the highest antioxidant potential of GHIPEs (with 2% GML) was confirmed through DPPH and ABTS free radical scavenging assays. Furthermore, the GHIPEs can release thyme essential oil in response to microbial growth, demonstrating their “smart sensing and targeted release” ability. Ultimately, the application of the GHIPEs in the preservation of Cololabis saira significantly reduced the total colony count, pH, TVB-N, and TBARS values (P < 0.05). Consequently, a ready-to-eat Cololabis saira product with an extended shelf life of 7 d at 4 °C was successfully realized, indicating the effectiveness of GHIPEs in preserving seafood freshness. These findings offer novel approaches to maintaining the freshness of prepared aquatic foods.

Zinc oxide nanoparticles functionalized with cinnamic acid for targeting dental pathogens receptor and modulating apoptotic genes in human oral epidermal carcinoma KB cells.

Oral diseases are often attributed to dental pathogens such as S. aureus, S. mutans, E. faecalis, and C. albicans. In this research work, a novel approach was employed to combat these pathogens by preparing zinc oxide nanoparticles (ZnO NPs) capped with cinnamic acid (CA) plant compounds. The synthesized ZnO-CA NPs were characterized using SEM, FTIR, and XRD to validate their composition and structural features. The antioxidant activity of ZnO-CA NPs was confirmed using DPPH and ABTS free radical scavenging assays. The antimicrobial effects of ZnO-CA NPs were validated using a zone of inhibition assay against dental pathogens. Autodock tool was used to identify the interaction of cinnamic acid with dental pathogen receptors. ZnO-CA NPs exhibited potent antioxidant activity in both DPPH and ABTS assays, suggesting their potential as powerful antioxidants. The minimal inhibitory concentration of ZnO-CA NPs against dental pathogens was found 25µg/mL, indicating their effective antimicrobial properties. Further, ZnO-CA NPs showed better binding affinity and amino acid interaction with dental pathogen receptors. Also, the ZnO-CA NPs exhibited dose-dependent (5µg/mL, 15µg/mL, 25µg/mL, and 50µg/mL) anticancer activity against Human Oral Epidermal Carcinoma KB cells. The mechanism of action of apoptotic activity of ZnO-CA NPs on the KB cells was identified through the upregulation of BCL-2, BAX, and P53 genes. This research establishes the potential utility of ZnO-CA NPs as a promising candidate for dental applications. The potent antioxidant, anticancer, and effective antimicrobial properties of ZnO-CA NPs make them a valuable option for combating dental pathogens.

Antidiabetic activity of methanolic extract of Hibiscus sabdariffa Linn. fruit in alloxan-induced Swiss albino diabetic mice

Abstract The majority of natural diabetic medications come from fruits and vegetables. These natural medications help protect humans from negative impacts of chemical antidiabetics by scavenging free radicals. The present study aimed to explore the antioxidant and antidiabetic properties of methanolic extract of fruits of Hibiscus sabdariffa Linn. (MEHSF) in alloxan-induced Swiss albino diabetic mice. The dried coarse powder of Hibiscus sabdariffa Linn. fruits was subjected to methanol extraction. The antidiabetic activity was determined by using alloxan-induced (80 mg/kg body weight) diabetic mice. Following a 15-day treatment period, serum biochemical parameters including total cholesterol (TC), triglyceride (TAG), LDL-cholesterol (LDL), HDL-cholesterol (HDL), serum glutamic pyruvic transaminase (SGPT), and serum glutamic-oxaloacetic transaminase (SGOT) enzymes were estimated. The antioxidant activity was evaluated through a DPPH and ABTS free radical scavenging assay. Total phenolic content and total flavonoid content were assessed using established methods. MESHF, containing polyphenolic and flavonoid compounds, exhibited antioxidant properties. A 100 and 200 mg/kg significantly (p &lt; 0.05) lowered the blood glucose levels and improved biochemical parameters such as TC, TAG, LDL, and HDL in diabetic mice. Further, MESHF significantly (p &lt; 0.05) reduced the activity of the SGPT and SGOT in diabetic mice compared to untreated diabetic mice. These results suggest that MEHSF with promising antioxidant and antidiabetic potentials can be considered to be a probable new resource of the antidiabetic agent.

Rapid Analysis of Compounds from Piperis Herba and Piperis Kadsurae Caulis and Their Differences Using High-Resolution Liquid-Mass Spectrometry and Molecular Network Binding Antioxidant Activity.

There is a serious mixing of Piperis Herba and Piperis Kadsurae Caulis in various parts of China due to the similar traits of lianas, and there is a lack of systematic research on the compound and activity evaluation of the two. Likewise, the differences in compounds brought about by the distribution of origin also need to be investigated. In this study, high-resolution liquid-mass spectrometry (UPLC-Q-Zeno-TOF-MS/MS) was used to analyze samples of Piperis Herba from five origins and Piperis Kadsurae Caulis from five origins, with three batches collected from each origin. The compounds were identified based on precise molecular weights, secondary fragments, and an online database combined with node-to-node associations of the molecular network. The t-test was used to screen and analyze the differential compounds between the two. Finally, the preliminary evaluation of antioxidant activity of the two herbs was carried out using DPPH and ABTS free radical scavenging assays. The results showed that a total of 72 compounds were identified and deduced in the two Chinese medicines. These compounds included 54 amide alkaloids and 18 other compounds, such as flavonoid glycosides. The amide alkaloids among them were then classified, and the cleavage pathways in positive ion mode were summarized. Based on the p-value of the t-test, 32 differential compounds were screened out, and it was found that the compounds of Piperis Herba were richer and possessed a broader spectrum of antioxidant activity, thus realizing a multilevel distinction between Piperis Herba and Piperis Kadsurae Caulis. This study provides a preliminary reference for promoting standardization and comprehensive quality research of the resources of Piperis Herba using Piperis Kadsurae Caulis as a reference.

Pterostilbene binding to whey protein: Multi-spectroscopy and the antioxidant activity

In this study, Pterostilbene (Pte) was incorporated into whey protein isolate (WPI) to form a whey protein isolate-pterostilbene (WPI-Pte) complex. The interaction mechanism between these two components and its impact on the antioxidant performance of Pte were investigated through multispectral techniques and molecular docking. UV and fluorescence analyses revealed a distinct fluorescence static quenching mechanism of WPI by Pte, resulting in the formation of a complex with a 1:1 M ratio. Thermodynamic parameter assessments indicated that the interaction between Pte and WPI is a spontaneous non-covalent binding process, primarily driven by hydrophobic interactions, followed by hydrogen bonding. Molecular docking confirmed that Pte molecules become stably embedded within hydrophobic pockets formed by amino acid residues of the protein after interacting with protein and are surrounded by these residues. DPPH and ABTS free radical scavenging assays demonstrated that the binding of WPI and Pte enhances the antioxidant capacity by more than fourfold compared to free Pte. This study provides insights into the interaction, modification, and development of novel polyphenol antioxidant systems, thereby effectively harnessing its physiological benefits.

Antioxidant, Antiproliferative, Pro-apoptotic and cell cycle arrest properties of crude extract and biofractions of Hybanthus enneaspermus Linn. to combat breast cancer

Objective: According to the World Health Organisation, breast cancer is presently the most common cancer diagnosed in women globally. Polyphenolic compounds act as antioxidants, improve health, and reduce risk and proliferation of various types of cancers. Hybanthus enneaspermus Linn. is a beneficial medicinal plant, reported to possess antimicrobial, antioxidant, anti-inflammatory, neuroprotective, cardioprotective, and nephroprotective properties etc. Methods: The current study involved the evaluation the antioxidant, antiproliferative, apoptotic and cell cycle arrest potential of the ethanolic leaf extract of Hybathus enneaspermus Linn. (EEHE), its toluene soluble, toluene insoluble, ethyl acetate and methanol soluble biofractions viz. TFHE, ITHE, EFHE, and MFHE to combat breast cancer. In vitro antioxidant activities were evaluated using DPPH, Hydrogen peroxide, Nitric oxide and ABTS free radical scavenging assays. In vitro antiproliferative activity against MCF-7 cells was assayed using the Sulforhodamine method, while apoptosis and cell cycle assays were analysed by flow cytometry. Results: MFHE exhibited significant in vitro antioxidant activity with IC50 values of 21.10±0.39 μg/mL and 25.99±4.66μg/mL, when compared against standard ascorbic acid with IC50 values of 11.19±1.09 μg/mL and 9.30±0.26μg/mL in DPPH and nitric oxide assays respectively. EFHE displayed substantial antioxidant potential in ABTS and hydrogen peroxide assays with IC50 values of 40.38±0.88μg/mL and 99.11± 13.59μg/mL, while ITHE showed considerable activity with IC50 &lt; 100μg/mL in DPPH, nitric oxide and ABTS assays. TFHE demonstrated significant antiproliferative activity by sulforhodamine assay, with GI50 value of 10.22 6.72µg/mL, while EEHE and ITHE showed substantial activity with GI50 values of 41.42±3.74µg/mL and 64.37±7.07µg/mL respectively, as against the standard drug Adriamycin (GI50 &lt; 10µg/mL) used. In the apoptosis assay, ITHE showed 11.31±0.82% cells in late apoptosis and 34.48±1.57 % cells in necrosis as compared to standard Adriamycin indicated 13.67±1.02 % cells in late apoptosis and 8.58±0.65 % cells in necrosis. In cell cycle analysis, ITHE displayed significant apoptotic activity with 20.15±1.37 % cells in SubG1 phase and 13.99±1.65 % cells arrested in G2-M phase as compared to the control. Conclusion: The study thus revealed that MFHE, EFHE and ITHE biofractions showed significant antioxidant activities, while EEHE, TFHE and ITHE exhibited substantial antiproliferative activity against mammary cancer cells. Additionally, ITHE induced remarkable apoptotic activity and cell cycle arrest in the MCF-7 cells. The therapeutic benefits may be credited to the bioactive constituents present in the ITHE fraction viz. polyphenolics, flavonoids etc.; however, the molecular mechanisms may need to be evaluated further.

Phenolic composition and correlation with antioxidant properties of various organic fractions from Hertia cheirifolia extracts

Hertia cheirifolia L. is a medicinal plant that has been used for a long time in folk Mediterranean medicine. The aim of the present study was to analyze and compare the phenolic profile and the antioxidant potential of organic fractions from H. cheirifolia extracts. Crude methanolic extracts were firstly prepared from the different parts of the plant. Then four different organic fractions were obtained by fractioning each extract, using different solvents with increasing polarity (hexane, chloroform, and ethyl acetate). The Phenolic content was analyzed using a UV–Vis colorimetric methods followed by a qualitative and quantitative analysis by high performance liquid chromatography-diode array detector (HPLC-DAD) system. After that, the antioxidant potential of the different organic fractions was evaluated using DPPH and ABTS free radical scavenging assays, reducing power of iron (FRAP) and inhibition of β-carotene oxidation tests. Our results revealed that ethyl acetate fractions (EA) contained the highest content of total phenolics (100–250 mg GAE/g). Indeed, the ethyl acetate fraction from the flower extract (EA-F) displayed the lowest IC50 values for the scavenging of DPPH and ABTS free radicals (38.83 ± 0.34 µg/ml and 23.76 ± 0.11 µg/ml, respectively). Also, the strongest iron reducing power (2628.87 ± 16.47 µmol Fe2+Eq/ml) and the best rate of inhibition of the β-carotene oxidation (58.91 ± 5.79 %) were recorded. In sum, the present study suggests that, the organic fractions from H. cherifolia are potential natural antioxidants and this is probably related to their phenolics content and structure.

Chemical Composition, Synergistic Antimicrobial and Antioxidant Potential of Hibiscus rosa-sinensis L. Leaves Essential Oil and Its Major Compound

This study aimed to investigate the chemical composition, antioxidant and synergistic antimicrobial potential of Hibiscus rosa-sinensis L. (China rose) leaves essential oil and its major compound, Dioctyl phthalate (DOP). The essential oil was extracted from leaves by hydro-distillation using the Clevenger apparatus. The essential oil was characterized by Gas Chromatography-Mass Spectrometry (GC/MS) analysis which revealed the presence of DOP as a major compound. The essential oil and DOP were tested for antibacterial activity against Klebsiella sp. and Pseudomonas aeruginosa using the disc plate method, antifungal activity against Fusarium oxysporum by agar well diffusion method, and antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) free radical scavenging assays. The synergistic antimicrobial interaction of essential oil and DOP was also tested against standard antimicrobials: tetracycline, chloramphenicol, fluconazole, and clotrimazole. The maximum antimicrobial potential was exhibited by China rose leaves essential oil with minimum inhibitory concentrations (MIC) of 18.5, 11.5, and 23.0 μg/mL against Klebsiella sp., P. aeruginosa, and F. oxysporum respectively. Moreover, the essential oil exhibited synergistic interaction with standard antimicrobials with a 3.75 to 10 times decrease in their MIC values. The essential oil also exhibited median inhibitory concentration (IC50) values of 780, 800, and 860 μg/mL in DPPH, NO, and ABTS free radical scavenging assays respectively. Hence it can be concluded that China rose leaves essential oil has a huge significance in pharmaceutical industries as an alternative to synthetic antioxidants and antimicrobials in near future.

Architecture of Nanoantioxidant Based on Mesoporous Organosilica Trp-Met-PMO with Dipeptide Skeleton.

A nanoantioxidant of mesoporous organosilica (Trp-Met-PMO) based on the framework of tryptophan-methionine dipeptide was first designed and constructed by condensation between self-created dipeptide organosilica precursor (Trp-Met-Si) and tetraethyl orthosilicate (TEOS) in alkaline conditions under the template hexadecyl trimethyl ammonium bromide (CTAB). Trp-Met-Si was prepared by the reaction between dipeptide Trp-Met and conventional organosilicon coupling agent isocyanatopropyltriethoxysilane (IPTES) via a multiple-step reaction method. The material Trp-Met-PMO was confirmed by XRD, FT-IR and N2 adsorption-desorption analysis. The material Trp-Met-5-PMO with low amounts of organosilica precursor remained a mesoporous material with well-ordered 2D hexagonal (P6mm) structure. With increasing amounts of organosilica precursor, a mesoporous structure was still formed, as shown in the material Trp-Met-100-PMO with the highest amounts of organosilica precursor. Moreover, pore size distribution, surface area and porosity of Trp-Met-PMO are regulated with different amounts of organosilica precursor Trp-Met-Si. The antioxidant activity of Trp-Met-PMO was evaluated by ABTS free radical-scavenging assay. The results showed that antioxidant activity was largely enhanced with increasing contents of organosilica precusor Trp-Met-Si in the skeleton. The material Trp-Met-40-PMO exhibited maximum scavenging capacity of ABTS free radicals, the inhibition percent was 5.88%. This study provides a design strategy for nanoantioxidant by immobilizing short peptides within the porous framework of mesoporous material.

In vitro anticancer activity studies of Aspergillus terreus on uterine cervix Cancer cells

The exploration of new anticancer agents is in high demand owing to limitations of conventional therapies. This study was designed to evaluate the cytotoxic potential of Aspergillus terreus ethyl acetate extract on uterine cervix cancer cells. Secondary metabolites were extracted from broth cultures and total phenolic content was determined using the Folin-Ciocaltiu method. Antioxidant activity was evaluated using DPPH and ABTS free radical scavenging assays. The cytotoxic activity of the fungal extract was assessed using Methyl ThaizolylTetazolium bromide (MTT) assay on HeLa cells. Morphological changes in HeLa cells upon treatment with the extract were determined. The effect of the fungal extract on cell cycle arrest was evaluated using flow cytometry. The extract showed a significant free radical scavenging activity. The total phenolic content was found to be 16.76 mg of gallic acid equivalents (GAE) per gram dry weight of the extract. The extract exhibited a cytotoxic effect on the HeLa cells with an IC50 value of 92.68 μg/mL. Cell cycle analysis revealed that A. terreus induced G0/G1 arrest confirming its anticancer activity. Results of the present investigation revealed that crude extract of the A. terreus possesses potential anticancer properties.

Hydrogel Containing Borassus flabellifer L. Male Flower Extract for Antioxidant, Antimicrobial, and Anti-Inflammatory Activity.

Borassus flabellifer L. is a plant in Arecaceae family, widely distributed and cultivated in tropical Asian countries. The purpose of this study was to identify the bioactive compounds of B. flabellifer L. male flower ethanolic extract and investigate the antioxidant, anti-inflammatory, and antibacterial activities against Cutibacterium acnes. Total phenolic compounds and total flavonoids in B. flabellifer L. male flower ethanolic extract were determined by the Folin–Ciocalteu method and aluminum chloride colorimetric assay, respectively. Active substances in the extract and their quantities were analyzed by liquid chromatography and mass spectrometry (LC–MS/MS). The antioxidant evaluation was carried out using DPPH, ABTS free radical scavenging assays, and FRAP assay. C. acnes inhibitory activity was performed by the broth microdilution method. Anti-inflammatory activity was determined by the protein denaturation assay. In addition, gel containing different amounts of B. flabellifer L. male flower extract was formulated. The physical stability of the gel was observed by measuring viscosity and pH after six heating and cooling cycles, as well as 1-month storage at 4, 30, and 45 °C. The total phenolic content in the extract was 268.30 ± 12.84 mg gallic acid equivalent/g crude dry extract. The total flavonoid contents in the extract were 1886.38 ± 55.86 mg quercetin equivalent/g extract and 2884.88 ± 128.98 mg EGCG equivalent/g extract, respectively. The LC–MS/MS analysis revealed the presence of gallic acid, coumarin, and quercetin and the concentrations of quercetin, coumarin, and gallic acid in B. flabellifer male flower ethanolic extract were 0.912, 0.021, and 1.610 µg/mL, respectively. DPPH and ABTS antioxidant assays indicated that the B. flabellifer L. male flower extract had IC50 values of 31.54 ± 0.43 and 164.5 ± 14.3 µg/mL, respectively. FRAP assay revealed that the B. flabellifer male flower extract had high ferric ion reducing power. The extract was able to inhibit C. acnes bacteria with a minimum inhibitory concentration (MIC) of 250 mg/mL. At 250 and 500 µg/mL, the extract demonstrated the highest anti-inflammatory activity. The gel containing 31.25% w/w and 62.5% w/w showed good physical stability after six heating and cooling cycles, as well as 1-month storage.

Synthesis, characterization, and biological evaluation of novel selenium-containing chitosan derivatives

Though great efforts have been made to develop selenium polysaccharides with unique properties using HNO3-Na2SeO3 methods, the Se content is still low due to the poor esterification efficiency of H2SeO3. Herein, selenodiacetic acid (SA) was introduced into chitosan (CS) to synthesize O-selenodiacetyl chitosan (OSAC) and chitosan-ammonium selenodiacetate (CASA) by covalent and non-covalent interaction, respectively. The obtained CS derivatives were characterized by UV–vis, FTIR, 1H NMR, XPS, TGA, and XRD spectra, and the OSAC and CASA showed high Se content up to 15,720 ± 475 and 26,363 ± 698 μg/g. The OSAC and CASA demonstrated increased antioxidant activities compared to the CS in DPPH and ABTS free radical scavenging assays. Moreover, they exhibited a potent anticancer effect on HepG2 cells with the IC50 values of 0.918 and 1.459 μg/mL. Taken together, this study provides a promising strategy for the design of novel selenium polysaccharides with high Se content and greater biological activity.

Biomimetic of hydroxyapatite with Tridax procumbens leaf extract and investigation of antibiofilm potential in Staphylococcus aureus and Escherichia coli

In the last few decades, hydroxyapatite (HA) has become one of the most highly prized biominerals in the biomedical industry for orthopedic and dental applications. The focus of this research was to synthesize biomimetic HA from Tridax procumbens (TP) leaf extract and investigate their antibiofilm properties. The HA was made using the sol-gel method and the HA-TP biocomposite was made by precipitation method. The d.nm size of HA and HA-TP biocomposite was determined as 193.28 and 258.14 d.nm, respectively. The zeta potential of HA and HA-TP biocomposite was determined as −21.2 and −18.3 mV, respectively, and found highly stable. The FTIR study revealed that phytochemicals of TP were successfully impregnated into HA-TP biocomposite. The HA and HA-TP biocomposite were found spherical and agglomerated from SEM analysis. In HR-TEM analysis, the average diameter of the HA and HA-TP biocomposite were 16.57 – 64.22 nm and 51.71 – 138.68 nm, respectively. According to the EDX analysis, HA is primarily composed of calcium, oxygen, and phosphate, whereas, HA-TP biocomposite is primarily composed of calcium, phosphate, oxygen, and carbon. In the antioxidant assay, the IC50 value (concentration required to scavenge 50% of free radicals) of HA-TP biocomposite was determined as 156.69 ± 14.02 and 180.21 ± 12.84 µg/mL in DPPH and ABTS free radical scavenging assays, respectively. The MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) of as-synthesized HA-TP biocomposite against Staphylococcus aureus – ATCC 13565 and Escherichia coli – MTCC 41 were observed as 181.09 ± 21.47 and 317.30 ± 41.03, and 157.59 ± 32.18 and 264.03 ± 21.58 µg/mL, respectively. The as-synthesized HA-TP biocomposite has detrimentally affected the biofilm formation of both the tested bacteria S. aureus – ATCC 13565 and E. coli – MTCC 41. The study concluded that the as-synthesized HA-TP biocomposite could be highly helpful in the biomedical field for alleviating oxidative-stress-related disorders and inhibiting microbial biofilm formation.

Effects of Quercetin and Curcumin Combination on Antibacterial, Antioxidant, In Vitro Wound Healing and Migration of Human Dermal Fibroblast Cells.

Wound healing impairment due to a postponed, incomplete, or uncoordinated healing process has been a challenging clinical problem. Much research has focused on wound care, particularly on discovery of new therapeutic approaches for acute and chronic wounds. This study aims to evaluate the effect of the combination of quercetin and curcuminoids at three different ratios on the antimicrobial, antioxidant, cell migration and wound healing properties. The antioxidant activities of quercetin, curcuminoids and the mixtures were tested by DPPH and ABTS free radical scavenging assays. The disc diffusion method was performed to determine the antibacterial activities of quercetin, curcuminoids and the mixtures against S. aureus and P. aeruginosa. The cytotoxicity and cell migratory enhancing effects of quercetin, curcuminoids and the mixtures against human dermal fibroblasts were investigated by MTT assay, scratch assay and Transwell migration assay, respectively. The results showed the synergism of the quercetin and curcuminoid combination to inhibit the growth of S. aureus and P. aeruginosa, with the inhibition zone ranging from 7.06 ± 0.25 to 8.78 ± 0.38 mm, respectively. The DPPH free radical scavenging assay demonstrated that the combination of quercetin and curcuminoids yielded lower IC50 values (15.38–23.70 µg/mL) than curcuminoids alone (25.75 µg/mL). Quercetin and a 3:1 quercetin/curcuminoid mixture at non-toxic concentrations showed the ability to stimulate the migration of fibroblasts across the matrix, whereas only quercetin alone accelerated the wound closure of fibroblasts. In conclusion, the mixture of quercetin and curcuminoids at a 3:1 ratio was the best formulations for use in wound healing due to the antimicrobial, antioxidant and cell-migration-enhancing activities.

Effect of processing on the release of phenolic compounds and antioxidant activity during in vitro digestion of hulless barley

Hulless barley contains phenolic compounds and possesses various antioxidant activities. To clarify the effects of thermal processing and in vitro digestion on the release of phenolic compounds in hulless barley, we studied the phenolic components and antioxidant activities of hulless barley after steaming, roasting processes, and in vitro digestions. Both total phenolic content (TPC) and total flavonoid content (TFC) in raw hulless barley (HB, 4.14 mg/g DW and 1.53 mg/g DW, respectively) were higher than that of steamed hulless barley (SHB) and roasted hulless barley (RHB). In vitro digestion significantly released more ferulic acid from its bound form, but hydrolyzed some amount of flavonoid (luteolin). Chrysoeriol-7-O-glucouronide was significantly detected (412.13 µg/g DW in HB, 382.19 µg/g DW in SHB, and 396.91 µg/g DW in RHB) in all three hulless barley. The total released content of phenolic compounds obtained from each phase after digestion reached to 46% and 45% for SHB and RHB, which was higher than that in the HB (41%). The antioxidant assay (via DPPH and ABTS free radical scavenging assays) indicated that the capacity of HB was obviously higher than that of SHB and RHB in undigested group. For digested group, the ABTS+ assay order was following, undigested > oral > small intestine > gastric > large intestine. The DPPH assay results indicated the antioxidant capacity as the order of undigested > oral > gastric > large intestine. Correlation analysis showed that ferulic acid, chrysoeriol-7-O-glucouronide, luteolin, chrysoeriol, and luteolin-7-O-glucouronide contributed to the antioxidant activities. Hierarchical cluster analysis (HCA) grouped samples accordingly. Roasting process could be considered as a better daily thermal treatment for hulless barley than steaming in terms of phenolic compounds and their antioxidant activities.