Ferric Reducing Antioxidant Power Assay Research Articles

Comprehensive Analysis of Antioxidant Properties, GC-MS, and FTIR Profiles of Myrica esculenta Fruit Extracts from Western East Khasi Hills of Meghalaya.

This study investigates the phytoconstituents of Myrica esculenta fruit extracts using various solvents, including n-hexane, dichloromethane, ethyl acetate, methanol, and water. Qualitative phytochemical analysis revealed the presence of several phytochemicals, with the highest concentration found in the methanol extract. The total phenolic (94.5±0.96 mg gallic acid equivalent (GAE)/g) and flavonoid (74.27±0.29 mg quercetin equivalent (QE)/g) contents were also highest in the methanol extract. Antioxidant activity was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic) acid (ABTS), and Ferric Reducing Antioxidant Power (FRAP) assays. The methanol extract exhibited superior antioxidant activity with DPPH and ABTS IC50 values of 22.27±0.98 μg/ml and 19.69±0.36 μg/ml, respectively, compared to ascorbic acid. FRAP activity was also highest in the methanol extract (87.125±0.33 mg Trolox equivalents (TE)/g). Gas Chromatography-Mass Spectrometry (GC-MS) analysis identified antioxidant compounds hexanedioic acid, bis(2-ethylhexyl) ester, methyl 11,12-octadecadienoate, and pentadecanoic acid. while Fourier Transform Infrared Spectroscopy (FTIR) analysis detected functional groups such as alkenes, ketones, esters, alcohols and carboxylic acids. These findings suggest that the methanolic extract of M. esculenta fruits is a rich source of natural antioxidants, making it suitable for pharmaceutical, health, and nutritional supplements aimed at enhancing overall health.

In vitro and computational investigation of antioxidant and anticancer properties of Streptomyces coeruleofuscus SCJ extract on MDA-MB-468 triple-negative breast cancer cells

This study aimed to explore the antioxidant potential of the ethyl acetate extract of Streptomyces coeruleofuscus SCJ strain, along with its inhibitory effects on the triple-negative human breast carcinoma cell line (MDA-MB-468). The ethyl acetate extract’s total phenolic and flavonoid contents were quantified, and its antioxidant activity was investigated using DPPH (1,1-Diphenyl-2-picrylhydrazyl), ABTS (2,2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid), and FRAP (Ferric Reducing Antioxidant Power) assays. Furthermore, the cytotoxic effect of the organic extract from Streptomyces coeruleofuscus SCJ on MDA-MB-468 cancer cells was assessed via the crystal violet assay. In tandem, a thorough computational investigation was conducted to explore the pharmacokinetic properties of the identified components of the extract, utilizing the SwissADME and pKCSM web servers. Additionally, the molecular interactions between these components and Estrogen Receptor Beta, identified as a potential target, were probed through molecular docking studies. The results revealed that ethyl acetate extract of SCJ strain exhibited remarkable antioxidant activity, with 39.899 ± 1.56% and 35.798 ± 0.082% scavenging activities against DPPH and ABTS, respectively, at 1 mg/mL. The extract also displayed significant ferric reducing power, with a concentration of 1.087 ± 0.026 mg ascorbic acid equivalents per mg of dry extract. Furthermore, a strong positive correlation (p < 0.0001) between the antioxidant activity, the polyphenol and the flavonoid contents. Regarding anticancer activity, the SCJ strain extract demonstrated significant anticancer activity against TNBC MDA-MB-468 cancer cells, with an inhibition percentage of 62.76 ± 0.62%, 62.67 ± 0.93%, and 58.07 ± 4.82% at 25, 50, and 100 µg/mL of the extract, respectively. The HPLC-UV/vis analysis revealed nine phenolic compounds: gallic acid, sinapic acid, p-coumaric acid, cinnamic acid, trans-fereulic acid, syringic acid, chloroqenic acid, ellagic acid, epicatechin. Streptomyces coeruleofuscus SCJ showed promise for drug discovery, exhibiting antioxidant and anticancer effects.

Antioxidant activities of Saudi honey samples related to their content of short peptides

This study explored the effect of geographical and floral origins on the antioxidant activities of Saudi honey samples related to their content of short peptides originated from honeybee proteins. The studied antioxidants were the total protein concentration, catalase activity, phenolic acids and flavonoids. The antioxidant activity assays included were the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, the ferric reducing antioxidant power (FRAP) assay and Ascorbic acid Equivalent Antioxidant Capacity (AEAC). The studied honey samples were obtained from the southwestern region of Saudi Arabia, namely Asir (65) and Jazan (25). The floral origins of the honey samples were Acacia (51), Ziziphus (4) and polyfloral (35). The LC/MS technique was used to detect the short peptides and the mascot database was used to identify the short peptides, their precursor proteins and the protease enzymes that produce them. Jazan honey was characterized by high number of short peptides. The short peptides were originated from honeybee proteins by the action of proteases from the honeybees and bacteria. The antioxidant activity of the honey samples increase with the increase of their content of short peptides and proteins. The amino acids type and sequence of the short peptides qualify them to act as antioxidant, antimicrobial, anti-diabetic, anti-hypertension, immunomodulatory and cholesterol lowering peptides.

Exploring the Antimalarial Potential ofEntandrophragma utileandMelochia umbellataExtracts.

Resistance remains the fundamental problem with antiplasmodial treatments. The study investigated the antiplasmodial, cytotoxic, and antioxidant properties of two Cameroonian medicinal plants, Entandrophragma utile and Melochia umbellata. Antimalarial activity against Plasmodium falciparum strains 3D7 and Dd2 was assessed using the SYBR Green I assay. Cytotoxicity was assessed against Raw and Vero cells using the resazurin assay, and against red blood cells using a hemoglobin release quantification assay. Antioxidant potential was determined using DPPH (2, 2-diphenyl-1-picrylhydrazine), ABTS (2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), and FRAP (ferric-reducing antioxidant power) assays. The most bioactive extract was further analyzed using ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) to determine its phytochemical composition. Extracts from E. utile exhibited moderate anti-malarial activity against Plasmodium falciparum (IC50 = 32.81-100 µg/mL), while M. umbellata leaf extract (MULAE) showed strong activity (IC50 = 11.62 and 11.91 µg/mL). All extracts demonstrated antioxidant activity (9.22 to 135.8 µg/mL), were selective for Raw and Vero cells, and were not toxic to red blood cells. UHPLC-MS analysis annotated potential pyrimidones, phenolic compounds, and terpenoids in MULAE. MULAE exhibited better antiplasmodial activity, suggesting the presence of unique bioactive compounds. Further research, including in vivo investigations, is needed to develop safe and effective antiplasmodial therapies.

Pharmacological Potential and Electrochemical Characteristics of Typha angustifolia Pollen

Typha angustifolia L. (TA) pollen has been utilized as a traditional Chinese medicine for treating various internal and external traumas. Moreover, bioactive compounds possess diverse pharmacological activities. This study aims to evaluate the antiviral properties of TA based on its ability to generate bioenergy, capable of inhibiting viruses. TA pollens were extracted using water and ethanol solvents. These extracts were utilized to identify the phytochemical contents and correlate with the antioxidant activity via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. HPLC analysis was conducted to identify its electron-shuttling compositions. The bioenergy-generating characteristics were determined via microbial fuel cells. The water extract (TA-W) showed higher antioxidant activity due to a higher phenolic and flavonoid content compared to the ethanol extract (TA-E). Quercetin-3-O-(2G-α-L-rhamnosyl)-rutinoside, quercetin-3-O-neohesperidoside, and quercetin are the electron shuttles (ES) identified out of the 11 compounds. TA obtained a 1.39 ± 0.10 amplification factor of power generation that indicates potential bioenergy-generating and associated antiviral characteristic properties. The findings may provide a foundation for developing antiviral medications specifically designed to target virus-related diseases, while minimizing the risk of drug toxicity and reducing the costs of drug development.

Assessment of the Antioxidative Properties of Extracts from the Fruits of Pyrus pyraster (L.) Burgsd and Pyrus ×myloslavensis Czarna &amp; Antkowiak Grown under Natural Environmental Conditions

Analyses were conducted on extracts from the fruits of P. pyraster and P. ×myloslavensis. Extraction with 80% methanol was performed at room temperature. The total phenolic content was determined by spectrophotometry using the Folin–Ciocalteu reagent, with gallic acid as the reference standard. Phenolic compounds and organic acids were identified on a liquid chromatograph. The antioxidative activity of the extracts was tested in relation to linoleic acid incubation of the emulsions for 19 h based on the neutralization of the DPPH radical (2,2-diphenyl-1-picrylhydrazyl) and the ABTS cation radical (2,2′-azino-bis[3-ethylbenzothiazoline-6-sulfonic acid]) as well as by the ferric reducing antioxidant power (FRAP) assay. The analyses showed that the extract from P. pyraster fruits is characterized by a higher content of phenolic compounds and a higher antioxidative potential compared with that from P. ×myloslavensis. In extracts of both pear species, seven phenolic compounds and four organic acids were identified. The total fiber content in pears of P. pyraster and P. ×myloslavensis was determined at 36.45 g and 24.74 g/100 g d.m. of the pear fruits, of which most comprised the insoluble fraction (32.49 g and 20.86/100 g, respectively). The results of the conducted research are highly significant, as they confirm that pears contain many valuable nutrients and biologically active compounds, including antioxidants and dietary fiber. Adding pear extracts to food products may offer a way to boost their health benefits while also broadening the variety of items that have appealing sensory characteristics. Moreover, research has shown that fruit extracts can help to prolong the shelf life of food products by safeguarding them against lipid oxidation and the decline in their nutritional value.

Valorization of Pineapple Core Waste for Sequential Extraction of Phenolic Compounds and Carotenoids: Optimization Through Ultrasound-Assisted Method and Box–Behnken Design

AbstractIn this study, a pioneering cascade method involving ultrasound-assisted extraction (UAE) and Box–Behnken Design (BBD) was optimized to valorize pineapple core waste by the sequential extraction of, firstly phenolic compounds and, secondly, carotenoids. The effectiveness of the extraction was evaluated based on total polyphenol content (TPC) and antioxidant activity using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) assays. Characterization of the carotenoids was performed using high-performance liquid chromatography with a diode array detector (HPLC–DAD). The initial characterization of dry pineapple core (DPC) samples revealed their nutritional composition, including protein, lipid, and carbohydrate weight percentages of 1.20 ± 0.05%, 5.3 ± 0.4%, and 88.6 ± 0.5%, respectively. The high extractives content (40.0 ± 4.5%) suggests a substantial presence of phenolic compounds, making the pineapple core a valuable source of natural antioxidants. The optimal UAE conditions for phenolic compound extraction were 70% amplitude, 5 min extraction time, and 2 cycles, yielding an antioxidant extract rich in phenolic compounds with a desirability value of 81.2%. Therefore, DPC was considered a valuable source of natural antioxidants. The extraction of β-carotene also showed promising results with optimal UAE conditions of 20% amplitude, 3 min extraction time, and 2 cycles. This research promotes the sustainable use of pineapple waste and demonstrates the potential to obtain valuable additives for the food, pharmaceutical, and cosmetic industries, encouraging a more circular and efficient use of resources in the pineapple processing industry.

Exploring of Chemical Profile and Biological Activities of Three Ocimum Species From Comoros Islands: A Combination of In Vitro and In Silico Insights.

Ocimum species have a great interest in different traditional medicinal systems. This study examined the chemical composition, antioxidant properties, enzyme inhibitory effects, and antibacterial and antifungal activities of the aerial parts of Ocimum gratissimum, Ocimum americanum, and Ocimum basilicum from the Comoros Islands. The extracts were analyzed using high-performance liquid chromatography-mass spectrometry (HPLC-MS) to determine their chemical composition. Antioxidant activity was assessed using 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), cupric reducing antioxidant capacity (CUPRAC), ferric reducing antioxidant power (FRAP), chelating ability, and phosphomolybdenum radical scavenging assays. Enzyme inhibitory activities against acetylcholinesterase (AChE), butrylcholinesterase (BChE), tyrosinase, amylase, and glucosidase were evaluated using spectrophotometric methods. Antibacterial and antifungal activities were tested using the broth microdilution method against selected pathogenic microorganisms. The selected enzymes and proteins were evaluated using in silico methods with biomolecules from these plants. In addition, 111 different metabolites were identified in the tested extracts using advanced HPLC/MS techniques. The most significant number of detected compounds were derivatives of hydroxycinnamic acids, followed by flavonoid glycosides and aglycones and derivatives of hydroxybenzoic acids. All three Ocimum species exhibited significant antioxidant activities, O. gratissimum exhibited the best-reducing abilities in CUPRAC and FRAP assays. In addition, enzyme inhibitory assays revealed that O. americanum had the most potent inhibitory effect on tyrosinase (48.01 ± 3.89 mg kojic acid equivalent [KAE]/g), and amylase (1.08 ± 0.02 mmol acarbose equivalent [ACAE]/g). Antibacterial and antifungal tests demonstrated that the extracts possess broad-spectrum activity. Molecular docking results showed that compounds exhibited remarkable binding energies with target enzymes and proteins. The molecular dynamics simulations identified chicoric acid with MurE of Staphylococcus aureus complex as the most promising drug candidate. These findings support their traditional medical and nutraceutical uses and suggest possibilities for natural functional applications.

Green synthesis of Z-scheme CeO2 decorated ZnO nanocomposites for photodegradation of organic pollutants, antioxidant activity and its effects on seed germination

The present work aimed to report a green synthesis of CeO2@ZnO nanocomposites via co-precipitation method using azadirachta indica aqueous leaf extract. The characterization of the prepared CeO2@ZnO nanocomposites were done using XRD, FTIR, SEM, EDAX, UV–vis, and PL techniques to examine the structural properties, functional group, morphological and electronic properties. As prepared CeO2@ZnO nanocomposites have been used for photo degradation of Crystal Violet (CV), Methylene blue (MB) and Rhodamine B (RhB) dyes in presence of solar light in aqueous solution. From structural analysis the mean crystallite sizes of the synthesized nanocomposites varied from 27 nm to 9 nm. The degradation of MB, CV and RhB dyes follows pseudo-first order reaction rate with the rate constantsk1 for MB is 10.09 × 10−3 min−1, k1 for CV is 8.71 × 10−3 min−1, k1 for RhB is 0.92 × 10−3 min−1.The characterized nanocomposites were used for seedling growth, physiological and biochemical responses during seed germination. In CeO2@ZnO nanocomposites treatments, significantly higher values of shoot length and root length were observed in CZ1 (0.5, and 1 mg/ml) treated seedlings as compared to other samples. Similarly, the activities of ɑ-amylase and protease enzymes were recorded to be maximum for CZ1 nanocomposites. For instance, the increased activity of α-amylase was observed to be 2.12, 2.09, and 1.33 folds higher in CZ1, CZ2, and CZ3 (1 mg/ml) treated seedlings as compared to the control. Similarly, the protease activity was reported to be increased by 0.011 folds in CZ1 nanocomposites (1 mg/ml) treated seedlings as compared to the control. Furthermore, all the CeO2@ZnOnanocomposites have excellent DPPH, and ABTS free radical scavenging activities, confirmed by the Ferric-Reducing Antioxidant Power (FRAP) assay. The CZ1 nanocomposites showed the best results. The CeO2@ZnO nanocomposites were found to have no toxic effects on cellular division confirmed with improved mitotic index under different treatment regimens.

Effect of Different Drying Methods on Retention of Colour, Total Phenolic Content, Flavonoid Content and Antioxidant Activity in Pereskia bleo Leaves

Pereskia bleo, a widely cultivated plant known for its medicinal applications, contains abundant phytochemicals, including phenolics and flavonoids, predominantly in its leaves. The drying process, a standard practice for enhancing the shelf life, could affect the bioactive compounds within the leaves. Therefore, this study aims to evaluate the impact of various drying methods on the colour, total phenolic content, flavonoid content, and antioxidant activity of P. bleo leaves. The tested drying methods include shade, oven, microwave, and freeze-drying. The colour of fresh and dried leaves was assessed using a Minolta chromameter. The total phenolic content (TPC) and total flavonoid content (TFC) of the P. bleo leaves extracts were determined using the Folin-Ciocalteu’s and aluminium chloride colourimetric assay, respectively. Antioxidant capacities were analysed with DPPH radical scavenging and ferric-reducing antioxidant power assay (FRAP). The results showed that microwave drying has significantly less impact than the other drying methods on the colour attributes of the leaves (p&lt;0.05). Notably, microwave-dried P. bleo leaves demonstrated significantly higher TPC (77.31 ± 0.70 mg GAE/g dry extract) and TFC (35.79 ± 1.34 mg QE/g dry extract) compared to leaves dried using the other tested methods (p&lt;0.05). Additionally, microwave-dried P. bleo leaves displayed the highest DPPH inhibition (91.62%) and exhibited the most potent IC50 value (76.90 ± 1.06 µg/mL) compared to oven and shade-dried leaves (p&lt;0.05). P. bleo leaves dried with a microwave also recorded a significantly higher FRAP value (62.66 ± 0.10 µg TE/g dry extract) than oven-dried leaves (p&lt;0.05). In conclusion, microwave drying emerged to be an efficient drying method in preserving the colour and antioxidant properties of the P. bleo leaves, suggesting its potential as a favourable drying technique for retaining bioactive compounds in medicinal plant materials.

Antioxidant analysis of protein from fresh and dry leaf of Orthosiphon aristatus (Blume) Miq.

Orthosiphon aristatus (Blume) Miq. is a folklore plant consumed as brewed tea for various health benefits. The white variety of the plants leaf and stem are predominantly sold in the market in dried form, blooming as a natural herbal product. To date, no proteomics and antioxidant studies are available on the fresh and dried leaf protein extract of O. aristatus since most studies take an interest in the crude extracts of plants. Thereupon, this study focuses on the One-dimensional (1D) electrophoretic pattern of the fresh and dry leaf determined via sodium dodecyl-sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Additionally, antioxidant proteins are currently being focused on for their link to controlling disease through their potential to destroy free radicals that are present in excess. Hence, an antioxidant assay was conducted for the fresh and dry leaf protein extract using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical assay and ferric reducing antioxidant power (FRAP) assay. The electrophoretic pattern obtained resulted in approximately 16 and 10 bands for the fresh and dry leaves respectively. As for the antioxidant activity, the dry leaf had higher radical scavenging activity and higher reducing power compared to the fresh leaf. The findings obtained provides insight in to the protein content and antioxidant activity found in the protein extract of fresh and dry leaves of O. aristatus. Hence, further detailed study of the protein extracts could further unveil their therapeutic potential.

Evaluation of the proximate composition and antioxidant capacity of some seaweeds from the Konkan coast of India

Minerals, antioxidants, and other nutrients that promote health can be found in abundance in seaweeds. In this study, we evaluated the proximate composition and antioxidant capacity of some seaweeds from Konkan coast of India. There were notable differences in the proximate compositions between the species. The highest protein content was found in Pyropia vietnamensis (~49 mg. g−1 dw), whereas the highest carbohydrate (~83 mg. g−1 dw), lipids (56 mg. g−1 dw) and vitamins were found in Stoechospermum marginatum. Total phenolic content (TPC) and antioxidant activity were estimated from a Methanolic extracts. The antioxidant capacity of the seaweeds was evaluated using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, ABTS (2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), ferric reducing antioxidant power (FRAP) assay and hydrogen peroxide free radical scavenging activity assay. Folin-Ciocalteu method was used to quantify total phenolic content (TPC), and Ulva fasciata had the highest TPC (24.30 ± 3 mg GAE. g−1 dry weight). In U. fasciata, the antioxidant activity was ~62 %, with an IC50 value of 0.057 ± 0.01 mM. Acanthophora spicifera was found to have a strong reducing power, with an IC50 value 0.012 ± 0.002 mM. H2O2 scavenging activity (~79 %) with an IC50 value of 0.006 ± 0.001 mM and 67 % ABTS radical scavenging activity (IC50 = 0.005) was highest in S. marginatum. Analysis showed that TPC exhibited strong positive correlation with both the ferric reducing antioxidant potential and DPPH antioxidant activity. These results showed that these seaweeds have significant antioxidant capacity and rich nutritional properties, which suggest they could be useful sources of functional ingredients for dietary supplements and other food products.

Biological Activity, Cytotoxicity, and Phytochemical Content of Leaf Extracts of Matoa (Pometia pinnata) and Pulasan (Nephelium ramboutan-ake) From the Sapindaceae Family

This study sought to assess the leaf extracts of matoa (Pometia pinnata) and pulasan (Nephelium ramboutan-ake) for antimicrobial, antifungal, antioxidant, and cytotoxic activities, besides phytochemical content. Four extracts (hexane, ethyl acetate, ethanol, and water) were obtained from each plant via sequential extraction. The antimicrobial activities were evaluated using colorimetric broth microdilution methods. The antioxidant activities were studied using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric-reducing antioxidant power (FRAP) assays. The cytotoxicity was examined using mouse fibroblasts NIH/3T3 while the phytochemical content was detected using various chemical tests. Among the extracts, only the water extract of matoa and ethyl acetate extract of pulasan exerted bactericidal effects on Bacillus cereus (minimum bactericidal concentration (MBC): 0.63 mg/mL) and Staphylococcus aureus (MBC: 1.25 mg/mL), respectively. In contrast, all extracts, except hexane extract, of both plants exhibited fungicidal effects with minimum fungicidal concentrations of 0.31-1.25 mg/mL. All extracts of matoa leaves displayed higher DPPH radical scavenging activity and FRAP than the extracts of pulasan leaves. Notably, the water extract of matoa showed the lowest half-maximal inhibitory concentration (IC50) value of 9.88 ± 1.70 µg/mL and the highest FRAP value of 6.11 ± 0.51 mmol Fe2+ equivalent/g extract (n=3). These antioxidant activities were significantly correlated (p&lt;0.01) with the amounts of phenolic compounds in the extracts. All extracts of both plants, except water extracts, showed significant toxicities (p&lt;0.05) towards NIH/3T3 cells. Alkaloids, terpenoids, saponins, and glycosides were detected in the leaves of both plants. The matoa and pulasan leaves contained bioactive compounds with antibacterial, antifungal, and antioxidant activities.

Antioxidant, membrane stabilizing and thrombolytic potentials of the leaves of erythrina fusca lour

Erythrina fusca (Family: Fabaceae) is famous for many traditional healing. In the present study, the leaves of E. fusca were collected, dried, powdered and then extracted with methanol. It was further partitioned into n-hexane, dichloromethane and aqueous soluble fractions. All the extracts were subjected to antioxidant, membrane stabilizing and thrombolytic assays. In case of free radical scavenging assay, the aqueous soluble fraction showed highest scavenging activity. In ferric reducing anti-oxidant power assay, the dicholoromethane extract showed highest reduction of ferric ion in a dose dependent manner. In total antioxidant assay, the methanol extract and dichloromethane extract showed stronger capacity as antioxidant. During the determination of total phenolic and flavonoid contents, the methanol extract and dichloromethane soluble fraction showed higher contents of phenolics and flavonoids, respectively. The erythrocyte membrane stabilizing assay revealed the capacities of methanol extract and its aqueous fraction to stabilize the RBC membrane in both hypotonic solution- and heat- induced hemolytic conditions. However, the clot lysis ability of the E. fusca leaf extracts was not so prominent. Bangladesh J. Bot. 53(3): 439-445, 2024 (September)

The principal component analysis of antioxidant activities of Songgak, a traditional herbal drink in West Nusa Tenggara, Indonesia

Songgak is a traditional herbal tea of the Sasak Tribe in Lombok Island, Indonesia, formulated to strengthen people's stamina. Songgak is composed of seven kinds of roasted spices: Piper nigrum L., Coriandrum sativum L., Piper retrofractum Vahl, Myristica fragrans Houtt, Syzygium aromaticum, Elaeocarpus grandiflorus, and Helicteres isora. This study aimed to assess the benefits of Songgak and its constituent spices by evaluating their antioxidant activities, total phenolic content (TPC) and flavonoid content (TPC). Antioxidant activity tests were performed on the water extract of Songgak, ethanolic extract of Songgak, and ethanolic extract of seven spices of Songgak including 2,2′- diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP) assay. The antioxidant activity using DPPH method showed that the water extract of Songgak has a strong categorisation of antioxidant activity with DPPH IC50 value of 63.78±4.29 µg/mL. The constituent species of Songgak with the strongest antioxidant activity was S. aromaticum. Total phenolic content (TPC) and total flavonoid content (TFC) of Songgak tea were 26.85±4.29 mg GAE/g and 6.99±0.29 mg RE/gram, respectively. The correlation between TPC, TFC, and antioxidant activities was determined using principal component analysis (PCA). The loading plot showed that TPC and TFC were strongly correlated with the antioxidant activity (FRAP method) of Songgak tea and its constituent spices. These results revealed that the presence of flavonoid and phenolic compounds in the seven herbal medicinal plants were responsible for the antioxidant properties of Songgak as a healthy herbal drink. Therefore, consuming Songgak every day can be beneficial for preventing various diseases involving free radicals.

Antioxidant Activity and Oxidative Stress Survival of Limosilactobacillus reuteri LR92 in Fermented Milk with Juçara Pulp

Fermented milk with probiotic bacteria is a functional food, and adding fruit can enhance its taste. Juçara, the fruit of the Euterpe edulis Martius palm tree, is known for its natural antioxidant properties. This study aimed to assess the antioxidant capacity of milk fermented by Limosilactobacillus reuteri LR92 with juçara pulp (JFM) over 30 days of storage at 4 °C and its protective effect on probiotic cells against reactive oxygen species (ROS). Phenolic compounds and antioxidant activities were measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) assays during storage. The resistance of L. reuteri to hydrogen peroxide, superoxide anions, and hydroxyl radicals was also tested. The results indicated that JFM maintained stability in its composition, except for color, which showed reduced brightness by the end of the 30 days. Although antioxidant activity measured by DPPH and FRAP decreased (83.92–67.03 µmol TEAC.g−1 and 1185.64–830 g TEAC.100 g.mL−1, respectively), it remained higher than the control (21.90–24.50 µmol TEAC.g−1 and 235.77–229.87 g TEAC.100 g.mL−1, respectively). Phenolic content remained consistent. In addition, juçara pulp significantly protected L. reuteri cells from ROS. Therefore, juçara-enriched fermented milk not only improved antioxidant properties but also shielded probiotics from oxidative stress, highlighting its potential as a functional food with added health benefits.

Apple Pomace as a Potential Source of Oxidative Stress-Protecting Dihydrochalcones.

Among fruits, the apple is unique for producing large amounts of the dihydrochalcone phloridzin, which, together with phloretin, its aglycone, is valuable to the pharmaceutical and food industries for its antidiabetic, antioxidant, and anticarcinogenic properties, as well as its use as a sweetener. We analysed the phloridzin concentration, total phenolic content, and antioxidant activity in the peel, flesh, seeds, juice, and pomace of 13 international and local apple varieties. In the unprocessed fruit, the seeds had the highest phloridzin content, while the highest total phenolic contents were mostly found in the peel. In processed samples, phloridzin and the total phenolic compounds especially were higher mostly in juice than in pomace. Moreover, the total phenolic content was much higher than the phloridzin content. Juice showed the highest antioxidant activity, followed by the peel and flesh. Across all samples, antioxidant activity did not directly correlate with phloridzin concentrations, suggesting that the antioxidant activity ascribed to phloridzin may need re-evaluation. In the Ferric Reducing Antioxidant Power (FRAP) assay, phloridzin only showed antioxidant activity at high concentrations when compared to its aglycone, phloretin. Considering the large amounts of apple juice produced by the juice industry, residual pomace is a promising source of phloridzin. For technical use, processing this phloridzin to phloretin would be advantageous.

Antioxidant and antidiabetic activities of Zingiber officinale var. Rubrum extracted with natural deep eutectic solvents

Polyphenols and flavonoid compounds are known to have antioxidant activity and can reduce blood glucose levels. Zingiber officinale var. Rubrum is one of the plants with high polyphenol content. This study aimed to extract phenolic and flavonoid compounds from this plant with various solvents primarily natural deep eutectic solvents (NADES), namely 70% ethanol, NADES1 [citric acid: sucrose (1:1)], NADES2 [sucrose: glucose: fructose (1:1:1)], NADES3 [choline chloride: glycerol (1:2)], and NADES4 [glycerol: urea (1:1)]. The phenolic and flavonoid levels were determined using spectrophotometer, the antioxidant activity was measured using DPPH and Ferric Reducing Antioxidant Power (FRAP) methods, while the antidiabetic activity was evaluated using enzymatic assay of α -amylase and α-glucosidase enzymes. The findings indicated that all NADES outperformed 70% ethanol in extracting phenols, with NADES1 showing the highest phenolic content. Meanwhile, the highest flavonoid content was observed in extracts with 70% ethanol and NADES1. The results of antioxidant activity analysis using DPPH revealed that extracts with 70% ethanol, NADES1, and NADES4 exhibited considerable strength (IC50: 45-49 µg/mL), with the average values of the three solvents being not significantly different. From the results of the FRAP assay, NADES3 demonstrated the highest strength Antioxidants Activity Index (AAI: 29.24±3.08 mmol/g), whereas 70% ethanol showed the lowest strength (AAI: 22.76±5.23 mmol/g). The average AAI values for all solvents indicated no significant differences. Among the solvents, NADES1 exhibited very strong inhibitory activity against α-amylase (19.62±0.20 µg/mL), while for α-glucosidase, NADES1 was stronger (IC50: 57.36±6.08 µg/mL) than other solvents. In conclusion, NADES can be a promising tool for extracting secondary metabolites from Zingiber officinale var. Rubrum as it shows both antioxidant and antidiabetic activities.

Exploring antioxidative properties of xanthohumol and isoxanthohumol: An integrated experimental and computational approach with isoxanthohumol pKa determination

This study explores the antioxidative activities of xanthohumol (XN) and isoxanthohumol (IXN), prenylated flavonoids from Humulus lupulus (family Cannabaceae), utilizing the oxygen radical absorption capacity (ORAC) and ferric reducing antioxidant power (FRAP) assays along with computational Density Functional Theory methods. Experimentally, XN demonstrated significantly higher antioxidative capacities than IXN. Moreover, we determined IXN pKa values using the UV/Vis spectrophotometric method for the first time, facilitating its accurate computational modeling under physiological conditions. Through a thermodynamic approach, XN was found to efficiently scavenge HOO• and CH3O• radicals via Hydrogen Atom Transfer (HAT) and Radical Adduct Formation (RAF) mechanisms, while CH3OO• scavenging was feasible only through the HAT pathway. IXN exhibited its best antioxidative activity against CH3O• via both HAT and RAF mechanisms and could also scavenge HOO• through RAF. Both Single Electron Transfer (SET) and Sequential Proton Loss-Electron Transfer (SPLET) mechanisms were thermodynamically unfavorable for all radicals and both compounds.

Extraction Optimization of Quercus cerris L. Wood Chips: A Comparative Study between Full Factorial Design (FFD) and Artificial Neural Network (ANN).

From a circular bio-economy perspective, biomass valorization requires the implementation of increasingly efficient extraction techniques to ensure the environmental and economic sustainability of biorefining processes. This research focuses on optimizing the specialized metabolite extraction of Turkey oak chips from Quercus cerris L. by applying a 3 levels Full Factorial Design (FFD). The goal is to obtain an extract with the highest antioxidant activity [evaluated by 1,1-diphenyl-2-picryl hydrazyl (DPPH) scavenging activity and ferric reducing antioxidant power (FRAP) assays] and specialized metabolites content [measured as total phenolic content (TPC), total flavonoid content (TFC), condensed tannin content (CTC), and hydrolysable tannins content (THC)]. With this objective, three different variables were investigated and compared: temperature (20 °C, 50 °C, 80 °C), solvents EtOH/H2O (0%, 20%, 40%), and time (3 h, 6 h, 24 h), resulting in 27 different extracts. Following the FFD analysis, the optimal extractive conditions were determined to be 80 °C, 40% EtOH/H2O, and 19.8 h. Finally, the prediction ability of FFD was compared with that of artificial neural network (ANN) for DPPH scavenging activity, FRAP, and TPC data based on the coefficient of determination (R2), mean absolute error (MAE), and root mean square error (RMSE). The results indicated that ANN predictions were more precise than FFD ones; however, both methods were useful in optimizing the extraction process as they returned comparable optimized extraction parameters.