Ferric Reducing Antioxidant Power Methods Research Articles

Citrus limon Wastes from Part of the Eastern Cape Province in South Africa: Medicinal, Sustainable Agricultural, and Bio-Resource Potential.

The fruits of Citrus limon are often purchased for their vitamin C-rich juice, while the fruit peel and the tree leaves are discarded as wastes. This study obtained the chemical profiles of the essential oils (EOs) of C. limon wastes (the peel and leaves), evaluated their medicinal value as antioxidants, their potential for sustainable use in agriculture as an insecticide for post-harvest preservation of grains, and their potential as a bioresource in livestock feed formulations. The EOs were isolated from C. limon leaves and peel using a hydro-distillation method on a Clevenger apparatus. The oil constituents were identified using the gas chromatography-mass spectrometry (GC-MS) hyphenated technique. The oils were evaluated for their in vitro antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power methods. An insecticidal study was conducted using contact toxicity, fumigation, and repellence bioassay methods against Sitophilus zeamais (maize weevils). Finally, the predicted income from using lemon peel as an alternative or substitute ingredient for maize in livestock feed formulations was obtained through a conventional simulation method. Chemically, limonene was found to be present in all the EOs analyzed (12-52%), while α-pinene was only found in the fresh leaf and peel oils (13.3% and 10.6%). Caryophyllene oxide was identified as the major component of the dried leaf oil (17.7%). At 20 µg m, the dry peel oil exhibited the highest inhibitory activity (52.41 ± 0.26%) against the DPPH radical, which was comparable to L-ascorbic acid (a standard antioxidant) at 54.25 ± 3.55%. The insecticidal study revealed that the dry peel oil is a better insect repellent (73.33 ± 6.95% at 10 µL) and fumigant (LC50 = 0.17 µL g-1 after 48 h) natural agent compared to the peel oil. Conversely, the dry peel oil showed a better contact activity (LC50 = 1.69 µL g-1) against the maize weevils compared to the dry leaf oil. The simulation study showed the cost of using dry lemon peel as an alternative to maize in livestock feed formulation to be ZAR 2.8 billion, compared against the higher cost of feed formulation with maize, which currently stands at ZAR 24.9 billion. This study has shown that C. limon wastes (the peel and leaves) contain EOs with unique chemical profiles, valuable medicinal properties as free radical scavengers, and considerable insecticidal properties for agricultural use in post-harvest grain preservation, presenting a cost-effective and promising bioresource for livestock feed production.

Comparison of different methods for evaluating the antioxidant activity of instant Torbangun (Coleus amboinicus L.) drinks

Torbangun (Coleus amboinicus L.) is a natural breast milk stimulant with antioxidant activity. This study aimed to compare the antioxidant activity of instant Torbangun drinks (ITD) ethanolic extract using DPPH (2,2-diphenyl-1-picrylhydrazil), ABTS (2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid), and FRAP (Ferric Reducing Antioxidant Power) methods. Ethanolic extract of commercial Torbangun tea (CTT) and lactation booster milk (CLM) was also included in all analyses as a product reference. At the same time, vitamin C was used as an antioxidant standard. The antioxidant activity was expressed as EC50 value. Among breastmilk booster drinks, the sample with the highest antioxidant activity obtained from ABTS and FRAP methods was ITD (EC50 18.26 mg/mL) and CLM (EC50 0.187 mg/mL), respectively. Assessing with the DPPH method, the activity of ITD and CLM was not significantly different (EC50 35.200 mg/mL and 33.035 mg/mL, respectively), and those were higher than that of CTT (EC50 52.22 mg/mL). However, the antioxidant activity of all products was significantly lower than vitamin C in all analysis methods (EC50 < 0.05 mg/mL). This finding was proposed due to different antioxidant compounds and antioxidant mechanisms among breast milk booster products. This study also revealed that ABTS and FRAP were the most suitable methods for determining antioxidant properties in all samples.

Comprehensive Analysis of Phytochemical Composition, Antioxidant Potential, and Antibacterial Activity of T. polium

This study aims to thoroughly examine the chemicals and effects of the ethanol extract from T. polium’s upper parts. We used the Soxhlet method for extraction, resulting in an extract with a significant yield of 20.6%. Qualitative analysis identified a variety of compounds, such as tannins, saponins, reducing compounds, terpenoids, quinones, and alkaloids. In quantitative analysis using the colorimetric method, we found the extract was rich in total flavonoids (20.78 mg equivalent QE/g DW extract) and total polyphenols (227.43 mg equivalent GAE/g DW extract). To assess antioxidant potential, we used the ferric reducing antioxidant power (FRAP) method, with ascorbic acid and butylated hydroxytoluene (BHT) as standards. The extract showed moderate activity in both the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and FRAP methods at concentrations of 65 µg/mL and 21 mg/mL, respectively. Additionally, we tested the ethanolic extract against various bacteria using the disk diffusion technique on agar medium. The results indicated that the T. polium extract had moderate effectiveness against Gram-negative bacteria like Pseudomonas aeruginosa ATCC 9027 and Escherichia coli ATCC 8739, as well as Gram-positive bacteria like Staphylococcus aureus ATCC 6538 and Bacillus subtilis ATCC 6633. We further investigated the composition of the ethanolic extract through LC-MS/MS analysis, establishing a detailed profile of phenolic compounds, with six flavonoids identified as the main polyphenolic constituents. This thorough evaluation provides insights into the potential therapeutic uses of T. polium.

In Vitro Test of Antioxidant Activity of Leilem Leaf Ethanol Extract (Clerodendrum minahassae) Using DPPH and FRAP Methods

The risk of degenerative diseases is increasing due to unhealthy lifestyles. Many people consume junk food, smoke, and do not protect themselves from sun exposure and pollution, exposing their bodies to free radicals. Free radicals can cause oxidative stress, necessitating the need for antioxidants to neutralize them. The leilem plant (Clerodendrum minahassae) is an endemic plant from North Sulawesi that is often used in traditional dishes and medicine. Moreover, leilem leaves are believed to be a source of natural antioxidants. This study aimed to determine the efficacy of leilem leaf ethanol extract as a source of antioxidants. The antioxidant potential was evaluated using phytochemical screening and antioxidant assays such as 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power (FRAP) methods, with ascorbic acid as a comparison. The level of antioxidant activity was measured by determining the IC50 value, which corresponds to the concentration of extract required to inhibit 50% of free radicals. The results of phytochemical screening showed that the ethanol extract of leilem (Clerodendrum minahassae) leaves contains active compounds such as phenols, flavonoids, saponins, tannins, steroids/triterpenoids, and alkaloids, indicating a high potential for antioxidant activity. The IC50 value for the DPPH method was 78.799 ppm, and the IC50 value for the FRAP method was 92.127 ppm. These results demonstrate that the ethanol extract of leilem leaves has strong antioxidant activity in both the DPPH and FRAP methods.

New penta-Coordinated Cadmium(II) Complexes: Synthesis, Characterization, Thermal, Antimicrobial, Antioxidant and Cytotoxicity Properties.

In this paper, a new tridentate Schiff base ligand (L) with nitrogen donor atoms and its cadmium(II) complexes with the general formula of CdLX2 (X=Cl-, Br-, I-, SCN-, N3 -, NO3 -) have been synthesized and characterized by physical and spectral (FT/IR, UV-Vis, Mass, and 1H, 13C NMR spectroscopies) methods. Also nano-structured cadmium chloride and bromide complexes were synthesized by sonochemical method and then used to prepare nanostructured cadmium oxide confirmed by XRD and SEM techniques. Thermal behavior of the compounds was studied in the temperature range of 25 to 900 °C under N2 atmosphere at a heating rate of 20 °C/ min. Moreover, thermo-kinetic activation parameters of thermal decomposition steps were calculated according to the Coats-Redfern relationship. Antimicrobial activities of the synthesized compounds against two gram-positive and two gram-negative bacteria such as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and two fungi of Candida albicans and Aspergillus niger were investigated by well diffusion method. SEM technique was used to monitor the morphological changes of the bacteria treated with the compounds. The 2,2-Diphenyl-1-picrylhydrazyl(DPPH) and the ferric reducing antioxidant power (FRAP) methods were used to evaluate the antioxidant ability of the ligand and its cadmium(II) complexes. In final, the cytotoxicity properties of the ligand and some cadmium(II) complexes against PC3 cancer cells were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) bioassay and nitric oxide (NO) level measurement. The morphological changes of prostate cancer (PC3) cells due to treatment with the ligand and its complexes confirmed their anticancer effectiveness.

Biorefining of legume and grass biomasses: Technological properties and bioactivities of the green juice

Five legume species (fodder galega, green pea, faba bean, red clover, and white clover) and one grass (timothy) grown under field conditions were investigated as potential future foods. Technological characteristics, such as emulsifying and foaming properties and nitrogen solubility indices, were determined from the green juices pressed from the whole plants. Secondly, the juices were evaluated for their antioxidative, antibacterial and anti-inflammatory properties. Faba bean green juice showed the highest emulsion stability and capacity, 66.0 ± 3.3 % and 18.0 ± 2.7 g/mg respectively, and second highest emulsion activity (58.4 ± 0.92 %). Considering the foaming properties, the highest activity was shown by white clover (433 ± 0.0 %) and green pea juices (411 ± 19.2 %). At the same time, the foam stability was remarkable for green pea juice (1078 ± 181.9 min) when compared to the other juices studied. The juices showed nitrogen solubility indices of about 50 % at pH 8, which were rather similar to those shown for the seeds of the same species in the literature. The antioxidant activities correlated with the total phenolic content. The highest antioxidant activity was shown by faba bean green juice both in the oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP) method. In addition, a weak positive correlation was observed between the total phenolic content and the antibacterial properties using Escherichia coli and Staphylococcus aureus strains, although mainly in the case of the latter strain, high inhibition readings were observed for all other plants than white clover. All juices showed some anti-inflammatory activity on human monocyte activation: the faba bean and red clover were the most efficient materials (IC50 concentrations 49 ± 41 and 206 ± 68 mg/L, respectively).- These results suggest that the green juices tested may provide novel health-promoting food and feed ingredients in the future.

A natural approach to breast cancer treatment: investigation of chemical features of aerial parts of endemic Onosma sintenisii Hausskn. ex Bornm and its antioxidant properties, in vitro cytotoxic and apoptosis induction on MCF-7 cells

ABSTRACT Onosma sintenisii Hausskn. ex Bornm. (O. sintenisii) belongs to the Boraginaceae family and it is an endemic species from Irano-turanian phytogeographical region (central and eastern Anatolia) that distributes in steppe areas. This study aimed to investigate the chemical composition, antioxidant, in vitro cytotoxic and apoptosis induction of methanol extract of aerial parts of O. sintenisii. As a result of GC/MS analysis, 14 components were identified, and the major compounds of the extracts are retronecine (13.94%), α.-D-Glucopyranosiduronic acid (10.86%), melaniline (7.5%) and 1,2-Butanediol (4.02%), respectively. Antioxidant properties of O. sintenisii were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP) and superoxide radical scavenging activity methods. While the DPPH free radical scavenging activity results of O. sintenisii extract varied between 62.49% and 32.27%, reducing power activity and superoxide radical scavenging activity were found to be low. The result of the MTT assay revealed strong anticancer activity of O. sintenisii extract. The most significant cytotoxic effect was noted at a concentration of 1000 µg/mL after 48 hours. These findings together with flow cytometry analysis suggest that apoptosis can be the main mechanism underlying cell death after O. sintenisii extract treatment.

Formulation of Functional Liquid Diets Under IDDSI Levels 0 to 2 for Dysphagia Patients: Physico-Chemical, Sensory, Antioxidant and Electromyographic Oral Processing Analyses.

Dysphagia is a significant health concern especially amongst the old age population. It is an ailment brought on by the weakening of the swallowing muscles. To reduce the risk of choking in dysphagia patients, the food is usually diluted to suit their swallowing ability. But dilution results in reducing the nutritional density of the foods thus causing undernutrition and malnutrition in patients. In this study, functional liquid diets were formulated under International Dysphagia Diet Standardization Initiative (IDDSI) levels 0-2. The developed diets were analysed for their proximate composition, colour, antioxidant and sensory properties. Antioxidant activities were determined using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+), 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and total phenolic content (TPC) methods. The highest ABTS+ value was observed in pumpkin puree (level-2) i.e. 98.59%. Black carrot juice (level-1) showed the highest DPPH free radical scavenging activity and FRAP value viz. 88.43% and 689.33µM TE/g, respectively. Electromyography (EMG) is an upcoming technique of food texture evaluation which provides real-time information about food oral processing. In this study, an EMG was conducted to measure the myoelectrical activity of human suprahyoid and masseter muscles by placing electrodes on the skin's surface during the oral processing of liquid. The EMG parameters correlated significantly with viscosity, ease of swallowing and IDDSI levels of the formulated diets. Hence EMG can be used as a tool for design and development of textured-modified diets for dysphagia patients. The sensory scores of formulated diets in this study were high indicating that these liquid diets may be incorporated into the diet plans of dysphagia patients.

Alkaloidal Extracts from Avicennia africana P. Beauv. (Avicenniaceae) Leaf: An Antiplasmodial, Antioxidant, and Erythrocyte Viable.

The emergence of drug-resistant parasites impedes disease management and eradication efforts. Hence, a reinvigorated attempt to search for potent lead compounds in the mangroves is imperative. This study evaluates in vitro antiplasmodial activity, antioxidant properties, and cytotoxicity of A. africana leaf alkaloidal extracts. The A. africana leaves were macerated with 70% ethanol to obtain a total crude extract. Dichloromethane and chloroform-isopropanol (3 : 1, v/v) were used to extract the crude alkaloids and quaternary alkaloids from the total crude. The antiplasmodial activities of the alkaloidal extracts were performed against 3D7 P. falciparum chloroquine-sensitive clone via the SYBR Green I fluorescence assay with artesunate serving as the reference drug. The alkaloidal extracts were further evaluated for antioxidant properties via the total antioxidant capacity (TAC), the total glutathione concentration (GSH), the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, and the ferric-reducing antioxidant power (FRAP) methods. The cytotoxic activity of the alkaloidal extracts was tested on erythrocytes using a 3-(4,5-dimethylthiazol-2-yl)-5-diphenyltetrazolium bromide-MTT assay with little modification. The phytocompounds in the alkaloidal extracts were identified via gas chromatography-mass spectrometry (GC-MS) techniques. The total crude extract showed good antiplasmodial activity (IC50 = 11.890 µg/mL). The crude and quaternary alkaloidal extracts demonstrated promising antiplasmodial effects with IC50 values of 6.217 and 6.285 µg/mL, respectively. The total crude and alkaloidal extracts showed good antioxidant properties with negligible cytotoxicity on erythrocytes with good selectivity indices. The GC-MS spectral analysis of crude alkaloidal extracts gave indole and isoquinoline alkaloids and several other compounds. Dexrazoxane was found to be the main compound predicted, with an 86% peak area in the quaternary alkaloidal extract. The crude and quaternary alkaloidal extracts exhibited antiplasmodial activities and ability to inhibit oxidative stress with negligible toxicity on erythrocytes. This may be good characteristics to avoid oxidative stress related to Plasmodium infection in the treatment of malaria.

Comprehensive In Silico Analysis of Uncaria Tomentosa Extract: Chemical Profiling, Antioxidant Assessment, and CLASP Protein Interaction for Drug Design in Neurodegenerative Diseases.

Uncaria tomentosa is a traditional medicinal herb renowned for its anti-inflammatory, antioxidant, and immune-enhancing properties. In the realm of neurodegenerative diseases (NDDS), CLASP proteins, responsible for regulating microtubule dynamics in neurons, have emerged as critical players. Dysregulation of CLASP proteins is associated with NDDS, such as Alzheimer's, Parkinson's, and Huntington's diseases. Consequently, comprehending the role of CLASP proteins in NDDS holds promise for the development of innovative therapeutic interventions. The objectives of the research were to identify phytoconstituents in the hydroalcoholic extract of Uncaria tomentosa (HEUT), to evaluate its antioxidant potential through in vitro free radical scavenging assays and to explore its potential interaction with CLASP using in silico molecular docking studies. HPLC and LC-MS techniques were used to identify and quantify phytochemicals in HEUT. The antioxidant potential was assessed through DPPH, ferric reducing antioxidant power (FRAP), nitric oxide (NO) and superoxide (SO) free radical scavenging methods. Interactions between conventional quinovic acid, chlorogenic acid, epicatechin, corynoxeine, rhynchophylline and syringic acid and CLASP were studied through in silico molecular docking using Auto Dock 4.2. The HEUT extract demonstrated the highest concentration of quinovic acid derivatives. HEUT exhibited strong free radical-scavenging activity with IC50 values of 0.113 μg/ml (DPPH) and 9.51 μM (FRAP). It also suppressed NO production by 47.1 ± 0.37% at 40 μg/ml and inhibited 77.3 ± 0.69% of SO generation. Additionally, molecular docking revealed the potential interaction of quinovic acid with CLASP for NDDS. The strong antioxidant potential of HEUT and the interaction of quinovic acid with CLASP protein suggest a promising role in treating NDDS linked to CLASP protein dysregulation.

Mixture-efficient identification of high-order herbal essential oil synergy using a normalized DiaMOND design

In this study, the effect of high-order combinations of Rosmarinus officinalis L. (R) EO with other essential oils obtained from selected Moroccan medicinal and aromatic plants, namely, Thymus satureioides Coss. (T), Origanum compactum Benth. (O), Pelargonium roseum L. (P), Artemisia herba-alba Asso. (A), and Salvia officinalis L. (S), was evaluated. The chemical composition of EOs was determined by GC/MS. Their antibacterial effect was determined using the microdilution method, whereas their antioxidant activity was evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing antioxidant power (FRAP) methods. The type of interaction between EOs was evaluated by the diagonal measurement of n-way drug interactions (DiaMOND). Antioxidant and antibacterial activity results demonstrate that O. compactum, T. satureioides, and P. roseum EOs tested alone showed significant efficacy. Using Principal Component Analysis (PCA) and hierarchical clustering analysis (HCA) modeling, one three-way combination (RST) was found with particularly strong synergistic DPPH radical scavenging (FIC3 = 0.50) and Fe3+ reducing (FIC3 = 0.48) properties. This combination also produced the highest activity against four bacteria strains (FIC3 = 0.38 for S. aureus, FIC3 = 0.38 for E. faecalis, FIC3 = 0.44 for E. coli, and FIC3 = 0.79 for P. aeruginosa). This mixture was, therefore, combined with conventional antibiotics. The results of all combinations showed a synergistic effect against four bacteria strains, which were tested with FIC2 ranging between 0.11 and 0.97. Our findings showed that a three-way combination of RST EOs constitutes a promising approach for possible application in the food and pharmaceutical industries.

Test the Antioxidant Effectiveness of Oyster Mushroom (Pleurotus ostreatus) Ethyl Acetate Fraction Cream Formula using FRAP (Ferric Reducing Antioxidant Power) and ABTS (2,2'-azino-bis (3-3) ethylbenzothiazoline-6-sulphonic acid) Methods)

molecules due to chemical reactions and metabolic events in the body. Phenolic compounds work to reduce the reaction of increasing the oxidation number, and are able to reduce highly reactive free radicals, lipid peroxidation processes, and metal oxides that can be obtained from oyster mushrooms. This study aims to make an antioxidant cream preparation and measure the IC50 value by conducting an antioxidant test of the ethyl acetate fraction of oyster mushroom (Pleurotus ostreotus) cream using FRAP (ferric reducing antioxidant power) and ABTS (2.2'-azino-bis (3-3) ethylbenzothiazoline-6-sulphonic acid) methods. Oyster mushrooms go through a liquid-liquid partition process and are made into cream preparations with a concentration of 2%, 4%, and 6% formulas, then the antioxidant activity is seen. Based on the measurement results of the three cream formulas, the IC50 value using the FRAP method was 110.12 in the medium category and the IC50 value with ABTS method was 84.61 in the strong category.&#x0D; &#x0D; Keywords: antioxidants; free radicals; oyster mushroom; frap; abts.

Nutritionally Important Pro-Health Active Ingredients and Antioxidant Properties of Fruits and Fruit Juice of Selected Biennial Fruiting Rubus idaeus L. Cultivars.

Raspberry fruits are an important source of many biologically active chemical compounds exerting nutritional and pro-health effects. The study presents a comparative analysis of nutritionally important bioactive chemical compounds-polyphenols; flavonoids, including anthocyanins; vitamin C; amino acids; fatty acids; and primary metabolites-contained in the fruits of three biennial fruiting cultivars, R. idaeus 'Glen Ample', 'Laszka', and 'Radziejowa', i.e., common cultivars in Poland and Europe. The antioxidant activity of fresh fruits and juice was determined with five methods. The analyses revealed the strong free radical scavenging potential of the fruits and juice, confirmed by the high concentration of nutrients, e.g., polyphenols, anthocyanins, vitamin C, amino acids, and fatty acids. The antioxidant activity of the juice determined with the ferric reducing antioxidant power (FRAP) and OH radical methods was from 2.5 to 4.0 times higher than that of the fruits. The following orders of total polyphenol contents were established in the analyzed cultivars: 'Glen Ample' < 'Laszka' < 'Radziejowa' in the fruits and 'Glen Ample' < 'Radziejowa' < 'Laszka' in the juice. The highest antioxidant activity was exhibited by the 'Radziejowa' fruits. Given their high content of dietary fiber, the fruits of the analyzed raspberry cultivars can be consumed by dieting subjects. The concentrations of vitamin C (28-34 mg/100 g) and anthocyanins (20-34 mg/100 g) indicate the biological and pharmacological activity of these fruits. The main unsaturated fatty acids in the fruits were gamma-linoleic acid (C18:2n6c) and alpha-linolenic acid (C18:3n3), which neutralize excess free radicals. The amino acids nutritionally essential to humans were dominated by leucine, arginine, and phenylalanine. This is the first comparative analysis of the antioxidant activity of fruits and juice and the contents of selected active compounds in the fruits of biennial fruiting cultivars of R. idaeus, i.e., a highly commercialized crop in Europe.

Chemical composition, minerals concentration, total phenolic compounds, flavonoids content and antioxidant capacity in organic and conventional vegetables

The demand for organic vegetables is increasing worldwide, which has led to the growth of organic agriculture. However, information on chemical composition and antioxidant activity in vegetables grown organically under controlled conditions remains uncertain. For this study, 3 vegetables widely consumed in Brazil were cultivated in controlled organic and conventional cultivation systems: lettuce, coriander and tomato. Their chemical composition, mineral concentration, phenolic compound content, flavonoids and antioxidant activity (AA) were evaluated. The analyses of chemical and mineral composition revealed differences between the cultivation systems. Organic lettuce presented higher content of ashes, calcium and potassium. A higher content of phenolic compounds and flavonoids was observed in most organic vegetables. Using the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) assay, the organic tomato exhibited higher AA compared to conventional, while the ferric-reducing antioxidant power (FRAP) method showed higher AA for organic coriander and tomato than theirs conventional version. The correlation between bioactive compounds and AA was positive, higher and stronger for organic vegetables, considering phenolic compounds (including flavonoids) and DPPH or FRAP antioxidant activity. Principal Component Analysis (PCA) disclosed that organic lettuce and coriander were grouped according bioactive components. In general, organic vegetables showed better results for bioactive compounds and antioxidant activity.

Direct microwave treatment enhances antioxidant and antibacterial properties of the seed extracts of Kékfrankos grapes

The Kékfrankos is the most frequently cultivated wine grape in Hungary, with a significant national and regional impact, resulting in considerable amounts of byproducts (e.g. pomace, seeds). To the best of our knowledge no research has been conducted on the antioxidant and antibacterial properties of its seed extracts (GSE). A novel apporach of applying direct microwave treatment on grape seeds was implemented for the first time to enhance antioxidant and antimicrobial properties of GSE. Antioxidant properties were assayed using the DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (Ferric Reducing Antioxidant Power) and TPC (Folin-Ciocâlteu's Total Polyphenol Content) methods. Profile and content of polyphenols was studied using high-performance liquid chromatography/tandem mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry. Antibacterial properties were evaluated using Gram-positive Staphylococcus aureus (SA), methicillin-resistant Staphylococcus aureus (ST239) (MRSA) and Gram-negative Escherichia coli (EC) bacteria strains. Results proved that the mild direct microwave treatment of grape seeds significantly increased total polyphenol, (+)-catechin, (−)-epicatechin as well as antioxidant capacity levels by 20–30 % compared to untreated samples and resulted the best antibacterial properties based on bacterial growth curves (SA and MRSA: 0.015625 mg/mL, EC: 0.25 mg/mL). Results justify the importance of further pharmacological investigations on Kékfrankos grape seed extracts and that the direct microwave treatment of grape seeds is an innovative approach for the fast and cost efficient improvement of the antibacterial properties of grape seed extracts.

Exploring green extraction methods to obtain polyphenols from partially defatted chia (Salvia hispanica L.) flour

Aim: The extraction of polyphenols is commonly accomplished using conventional techniques such as solid-liquid and liquid-liquid extraction, which are associated with the use of high quantities of organic solvents, long extraction times, and low selectivity and reproducibility. These limitations have led to the development of innovative extraction technologies. The purpose of this study was to investigate the ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) of polyphenols from partially defatted chia flour (PDCF). Methods: The effect of four factors on the extraction of polyphenols (percentage in relation to the initial weight of PDCF) and on the antioxidant activity [quantified by 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and ferric reducing antioxidant power (FRAP) methods] was investigated and the UAE and MAE processes were optimized using the response surface methodology (RSM). Results: It was found that MAE improved the extraction yield (polyphenol content and antioxidant activity) in shorter extraction times when compared to UAE. Conclusions: The application of these alternative green technologies improved the performance of the polyphenol extraction process from PDCF. Overall, both techniques could be used as efficient green alternatives.

Evaluation of natural extracts’ antioxidant capacity for controlling fresh sausage oxidation

Lipid oxidation impacts the quality and shelf life of meat products. The use of natural antioxidants is an alternative to delay their oxidative deterioration. This study aimed to determine the antioxidant activity of natural extracts and evaluate the viability of replacing 2,3-tert-butyl-4-hydroxyanisole (BHA) in fresh sausages. Both tocopherols and grape seed extract showed similar antioxidant activity to BHA through the 2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical (DPPH) and ferric reducing antioxidant power (FRAP) methods. The effectiveness of these antioxidants applied to fresh sausage was evaluated during 15 days of storage at 4.0ºC under light incidence. The results indicated a pro-oxidant effect of grape seed extract (with 6.74% acidity and 2.74 mg MDA kg sample-1 thiobarbituric acid reactive substances (TBARS)) and showed the viability of replacing BHA with tocopherols. Tocopherols had a lower peroxide value (3.07 mE O2 kg-1) than the control (11.40 mE O2 kg-1), with no difference in TBARS or acidity content compared to BHA, and the lowest total mass loss (18.22%).

Chemical composition and antioxidant activity of petroleum ether fraction of Rosmarinus officinalis

The presented study examines the chemical composition and antioxidant activity of the petroleum ether fraction of Rosmarinus officinalis (PEF-RO), which was obtained via 75 % ethanol extraction followed by petroleum ether extraction. The obtained fractions were analyzed by gas chromatography-mass spectrometry (GC-MS). The in vitro antioxidant activity of PEF-RO was investigated using various assays, including 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate (ABTS) free radical scavenging, and ferric reducing antioxidant power (FRAP) method. A total of 82 chemical components were successfully identified, totaling 10.06 % of PEF-RO content. The identified components consisted of 24 hydrocarbons, 14 ketones, 16 alcohols, 4 phenols, 14 esters, and 10 other compounds. Notably, verbenone (2.4377 %), vitamin A (0.6854 %), trans-geraniol (0.5998 %), linolenic acid (0.5713 %), and 1,8-eucalyptol (0.5323 %) were the most abundant compounds, and there are many trace components in PEF-RO. PEF-RO's IC50 values of DPPH and ABTS free radical scavenging were determined as 0.36 mg/mL and 0.19 mg/mL, respectively. FRAP-method was employed to measure the total antioxidant energy of PEF-RO, which displayed good antioxidant activity. The obtained data provides the foundation for the comprehensive development and utilization of Rosmarinus officinalis.

Total phenolic and flavonoid contents and their antioxidant capacity of Curcuma xanthorrhiza accessions from Jambi

Abstract. Asyhar R, Minarni M, Arista RA, Nurcholis W. 2023. Total phenolic and flavonoid contents and their antioxidant capacity of Curcuma xanthorrhiza accessions from Jambi. Biodiversitas 24: 5007-5014. Curcuma xanthorrhiza Roxb., is an effective natural antioxidant and is widely used as a raw material for jamu in Indonesian traditional medicine. This study aims to evaluate the biochemical characteristics and antioxidant capacity of C. xanthorrhiza rhizome accessions. Ten accessions of C. xanthorrhiza rhizome from 10 districts in Jambi province were evaluated for total phenolic (TPC) and total flavonoid (TFC) content and antioxidant capacity using four methods: 2,2-diphenyl picrylhydrazyl (DPPH), 2,2 azinobis (3-ethyl benzothiazoline) -6-sulfonic acid (ABTS), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant power (CUPRAC). The content of total phenolic (TPC) and total flavonoids (TFC) varied from 1.74±0.085 to 18.72±1.47 mg GAE/g DW and 1.74±0.085 to 18.72±1.47 mg GAE/g DW, respectively. Antioxidant capacities ranged from 0.13-1.11, 0.72-4.14, 7.71-81.48, 18.37-211.68 µmol TE/g DW, assayed by DPPH, ABTS, FRAP, and CUPRAC methods, respectively. Antioxidant activity was significantly correlated with the polyphenol content of C. xanthorrhiza rhizome accessions. Accession to C. xanthorrhiza rhizome with the code JSS, JBE, JG, and JK has the capacity for polyphenolic compounds (phenolics and flavonoids) and antioxidant capacity compared to other accessions, indicating that these accessions are promising for further breeding programs and commercial purposes.

Evaluation of the effect of designed PLGA-arctiin nanoparticles modified with folic acid and chitosan on colon cancer cells.

In this study, we designed nanoparticles (NPs) based on polylactic acid glycolic acid modified with chitosan and folic acid to optimize the anti-cancer, anti-inflammatory, and antioxidant effects of arctiin (ARC), and we measured its effects on cancer cells, including colon cancer. NPs were synthesized using the W1/O/W2 double-emulsion solvent evaporation method. Physicochemical characteristics of synthesized NPs (ARC-PCF-NPs), including average particle size, dispersity index (PDI), zeta potential (ZP), field emission scanning electron microscope figures, and encapsulation efficiency (EE), were evaluated. 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) methods were carried out to determine the antioxidant properties of NPs. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay was performed to investigate cytotoxicity effects on cancer cells and normal fibroblasts. Quantitative polymerase chain reaction was also performed on inflammatory and antioxidant genes. The obtained results indicated that the synthesized NPs have a size of 100nm, a DPI of 0.36, a ZP of 26.30mV, and EE was calculated at about 87.5%. The antioxidant influence of ARC-PCF-NPs was confirmed by inhibiting ABTS and DPPH free radicals and ferrous reduction in the FRAP method. Moreover, the reduction of inflammatory and antioxidant genes confirmed the anti-inflammatory and antioxidant properties of NPs. These results indicate the modification of the surface of NPs in order to increase the bioavailability, stability, and effectiveness of medicinal compounds in therapeutic applications.