DPPH Scavenging Activity Research Articles

Phytochemical analysis and biological activities of various parts of Bulbine natalensis (Baker): A comparative study

Introduction: Bulbine natalensis is a succulent plant native to South Africa, used to treat various skin conditions. The purpose of this investigation was to analyse the phytochemical content, as well as antioxidant and antibacterial activities of various parts of B. natalensis. Methods: Phytochemical screening tests were performed to investigate the presence of ten compounds from B. natalensis methanol extract. Total phenolic, flavonoid, tannin, and proanthocyanidin content assays were followed to determine their concentrations in B. natalensis. The 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide (H2 O2 ), and iron chelating assays were used to assess the antioxidant activity. To determine the antibacterial properties of B. natalensis against Staphylococcus aureus and Escherichia coli, the agar-well diffusion method was adopted. Results: The phytochemical screening revealed more compounds present in the leaves. The underground stems yielded higher concentrations of total phenolics (1909.2 ± 4.8 mg gallic acid equivalent [GAE]/g), total flavonoids (259.7 ± 27.2 mg quercetin equivalent [QE]/g), and total proanthocyanidins (858.3 ± 1.7 mg catechin equivalent [CE]/g) in comparison to the leaves and roots. The roots showed stronger DPPH (0.36 ± 0.02 mg/mL) and H2 O2 (0.24 ± 0.04 mg/mL) scavenging activities. Only the underground stems and roots showed inhibition against S. aureus with the values of 15.33 ± 0.67 mm and 15.67 ± 0.33 mm, respectively, whereas the leaves displayed the highest inhibition against E. coli (18.33 ± 0.88 mm). Conclusion: The methanolic extracts of B. natalensis leaves, underground stems, and roots possess significant phytochemical content, in conjunction with antioxidant and antibacterial activities.

Antioxidant activity of Schiff base ligands using the DPPH scavenging assay: an updated review.

Schiff base ligands, formed from primary amines and carbonyl compounds, are potential antioxidants because they scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals via hydrogen atom transfer (HAT) and single electron transfer (SET) routes. This review aims to help design, synthesize, and discuss the antioxidant activity of Schiff base ligands based on their structure. This study critically discussed the solvent effect and the structural changes of Schiff base ligands responsible for DPPH scavenging activity, such as proton donating, electron-donating, and electron-withdrawing substituents, conjugation and ring structure. The ligands with electron-donating substituent groups in the phenolic ring demonstrated greater activity by readily stabilizing the radical and some of them showed higher activity than the standard. The activity also depends on the solvent used; the activity increases in those solvents that promote the proton and electron donation of the Schiff base. Schiff bases are most important due to their versatile applications, which can be explained by their antioxidant activity. The data led to the conclusion that the Schiff base ligand will serve as a source of synthetic antioxidants. There should be lots of scope for research on the antioxidant activity of Schiff bases. This review will assist researchers in studying Schiff base-based antioxidants and their applications. All the data analyzed in this paper was found from in vitro tests; for more clearance supplementary tests and in vivo investigations are crucial.

O-Alkyl derivatives of ferulic and syringic acid as lipophilic antioxidants: effect of the length of the alkyl chain on the improvement of the thermo-oxidative stability of sunflower oil.

Lipid oxidation is the major cause of the deterioration of fat-containing foods, especially those containing polyunsaturated fatty acids (PUFAs). Antioxidant additives of synthetic origin are added to matrices rich in PUFAs, such as sunflower oil (SO). However, there is controversy regarding their safety, and their low solubility in both water and fat has led to the search for new covalent modifications through lipophilicity. This work presents the synthesis of O-alkyl acid derivatives from ferulic and syringic acids and the study of their antioxidant capacity and effect on the thermoxidative degradation of SO. Antioxidant activities were evaluated by employing ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays in a concentration range of 10-100 µg mL-1. The IC50 values for DPPH scavenging activity ranged from 15.61-90.43 µg mL-1. The results of the FRAP assay for both O-alkyl ferulic (3a-f) and syringic (5a-f) series revealed a "cut-off" effect on antioxidant activity in carbon five (C5). Thermoxidation study of additives 3b-c and 5b-c showed a decrease in the slope of extinction coefficients K 232 and K 270 in comparison with SOcontrol. Furthermore, 3c presented higher antioxidant activity than 3b and 1, with a power to decrease the thiobarbituric acid reactive species (TBARS) 6 times higher than SOcontrol at 220 °C. Additives 5b-c exerted a protective effect on the thermoxidation of SO. The results suggest that increasing lipophilic and thermal properties of antioxidants through O-alkyl acid derivatization is an effective strategy for accessing lipophilic antioxidant additives with potential use in food matrices.

In Vitro Antibacterial and Antioxidant Activities, Pharmacokinetics, and In Silico Molecular Docking Study of Phytochemicals from the Roots of Ziziphus spina-christi.

Ziziphus spina-christi (Rhamnaceae family) is a medicinal plant traditionally used to treat dandruff, wounds, hair loss, diarrhea, mastitis, abdominal pain, and gastrointestinal complications. To support this, the present work aims to study the in vitro antibacterial and antioxidant activities of compound isolates from the roots of Ziziphus spina-christi along with their in silico computational analyses. Compounds were isolated on silica gel column chromatography and an agar disc diffusion and DPPH radical scavenging assays were employed to study the antibacterial and antioxidant activities, respectively. The ADME and toxicity properties of the compounds were evaluated using SwissADME and ProTox-II online Web tools, respectively. Conversely, the in silico molecular docking studies were attained via a Biovia Discovery Studio Visualizer 2021 in combination with the AutoDock Vina software. The silica gel chromatographic separation of the combined CH2Cl2 : CH3OH (1 : 1) and CH3OH root extracts afforded trimethyl trilinolein (1), stearic acid (2), 13-hydroxyoctadeca-9, 11-dienoic acid (3), β-sitosteryl-3β-glucopyranoside-6'-O-palmitate (4), and stigmasterol (5). Notably, the in vitro antibacterial study revealed the extract and β-sitosteryl-3β-glucopyranoside-6'-O-palmitate (4) with the highest inhibitory activities (15.25 ± 0.35 and 14.25 ± 0.35 mm, respectively) against E. coli compared to ciprofloxacin (21.00 ± 0.35 mm) at 2 mg/mL. The CH2Cl2 : CH3OH (1 : 1) extract (IC50 : 1.51 µg/mL) and β-sitosteryl-3β-glucopyranoside-6'-O-palmitate (4) (IC50 : 5.41 µg/mL) also exhibited auspicious DPPH scavenging activities, followed by stigmasterol (5) (IC50 : 6.88 µg/mL) compared to the ascorbic acid standard (IC50 : 0.46 µg/mL). The molecular docking analyses unveiled the highest binding affinity by β-sitosteryl-3β-glucopyranoside-6'-O-palmitate (4) (-8.0 kcal/mol) against P. aeruginosa PqsA relative to the ciprofloxacin standard (-8.2 kcal/mol). Furthermore, the organ toxicity predictions showed that all the compounds exhibit no hepatotoxicity and cytotoxicity effects and stigmasterol (5) affords drug-likeness protocols. Overall, the combined experimental and computational investigations of this study support the traditional uses of Ziziphus spina-christi for antibacterial and natural antioxidant applications.

Study on phytochemical properties and antioxidant activities of marine macroalgae Padina tetrastromatica Hauck

An abundance of beneficial plant life can be found in aquatic areas, particularly in marine ecosystems. These resources have, therefore, been in use for hundreds of years. Seaweeds have long been closely associated with human life as a source of food, fodder, fine chemicals, fertilizer and pharmaceutically significant drugs. Algae are an important group of organisms with the largest source of biogenic compounds. They are found to possess significant antioxidant and phytochemical activities. The aim of the present study was to investigate the phytochemical and antioxidant activity of active compounds present in the methanol extract of the brown algae, Padina tetrastromatica Hauck. The antioxidant activity of extracts was evaluated by DPPH scavenging activity and Hydroxyl radical-scavenging activity assays. The phytochemical analysis revealed the presence of alkaloids, flavonoids, steroids, saponins, carbohydrates, proteins and phenolic compounds etc.

Phytochemical Composition, Antioxidant and Antibacterial Studies on Celtis Timorensis Leaf Extract

Objective: The objective of the present investigation is to study the phytochemical composition, antioxidant and antibacterial activity of petroleum ether, chloroform, ethanol, methanol and water extracts of the leaf part of Celtis timorensis Spr. The preliminary phytochemical studies were conducted according to standard procedures. Total phenolic content was estimated using the FCA reagent method. The antioxidant efficiency of extracts was evaluated by using molybdate and DPPH methods. The antibacterial potency of leaf extracts was studied using the disc diffusion method against eight human pathogenic bacterial strains. Results: The results of preliminary phytochemical study revealed the presence of alkaloids, phytosterols, phenolic components, tannins, flavonoids, terpenoids, glycosides and saponins. The total phenolic content of the tested extracts exhibited a range between 8.82 to 68.32 mg GAE/g dwt. The highest total phenolic content was observed in the methanol extract (68.32±1.03 mg GAE/g dwt.) and the highest total antioxidant capacity was observed in the methanol extract of leaf part (700.0±0.71 mg ASE/g dwt.).Regarding DPPH scavenging activity the highest DPPH-reducing activity (>90%) was observed by methanol, ethanol and water extracts of the leaf part. Ethanol and water extracts of leaf samples strongly inhibited the gram-negative bacterial species Pseudomonas aeruginosa and Salmonella enterica (13 mm for each species) respectively. While gram-positive species i.e. Bacillus megatherium Artherobacter protophormiae and P. aeruginosa were moderately inhibited by chloroform, ethanol and water extracts (12 mm for each) respectively. Conclusion: In conclusion, the selected medicinal plant C. timorensis extracts exhibited good antioxidant activity, strong antibacterial activity and rich bioactive components. It required further studies on the isolation, and characterization of active principle to evaluate its pharmacological properties.

Bioactivities of Nek Kara (Dillenia excelsa (Jack) Martelli ex. Gilg) leaves from forest medicinal plants of Kutai Ethnic

The utilization of traditional medicine and treatment within the community of Kutai Kartanegara, East Kalimantan, Indonesia is characterized by a wide range of practices. Medicinal plant extracts containing secondary metabolites, possessing diverse molecular structures and biological activities, exhibit promising potential for the development of medicines targeting various diseases. Phenolic compounds, present in plants, exhibit numerous biological effects, including antioxidant and antimicrobial properties. These secondary metabolite compounds play a crucial role in safeguarding against disease-induced damage. Nek Kara (Dillenia excelsa (Jack) Martelli ex. Gilg), a forest plant, has been traditionally employed by the local population for the treatment of diabetes. The objective of this study is to investigate the biological activities of the ethanol extract derived from Nek Kara leaves. The analysis encompasses the examination of phytochemical content, toxicity, as well as antioxidant and antimicrobial activities of the extract. The antioxidant activity is assessed through DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activity using a spectrophotometer, while toxicity is determined via the BSLT (Brine Shrimp Lethality Test). The antimicrobial activity is evaluated using the diffusion method. The findings reveal the presence of phytochemical content, such as alkaloids, flavonoids, tannins, and steroids, within the ethanol extract derived from Nek Kara leaves. The BSLT results indicate the absence of toxic bioactivities in the ethanol extract. Furthermore, the Nek Kara leaf extract demonstrates potent antioxidant activity and exhibits inhibitory effects on the growth of bacterial and fungal colonies.

Proximate composition, mineral, vitamins and antioxidant activities of Cymbopogon citratus /dc/ stapt (lemon grass) and Oregamun vulgare (linn) leaves extracts harvested in Jos, North-Central Nigeria

There many factors that affects the physico-chemical features of plants, including, weather and climatic factors (lightintensity temperature, rainfall), pH, organic matter content, available nutrients etc. thus, the source of a plant plays a big role in its chemical and nutritive content. This study aimed to investigate the proximate composition, mineral, vitamins and antioxidant activities of Cymbopogoh citratus and Oregamun vulgare crude leave extracts (CCCLE and OVCLE), harvested in Zaramaganda, Jos, North-Central Nigeria. Fresh leaves of C. citratus and O. vulgare were harvested in Zaramaganda, Jos, North-Central Nigeria, prepared and extracted via cold water Soxhlet extraction. Chemical and nutritive composition of the two plant extracts were carried out by way of proximate analysis and atomic absorption spectrophotometry (AAS) while antioxidant activity was determined by radical scavenging assay using DPPH (1,1-Diphenyl-2-pierylhydrazyl) as an artificial free radical activity. Proximate analysis revealed varied proportions of the content in the investigated plants. The highest % by mass was; moisture content 7.33%, crude protein 16.25% and crude fibre 1.78% respectively in OVCLE while ash (12.54%) and fat (23.54%) content were highest in CCCLE. Mineral analysis revealed higher concentration of calcium, sodium, potassium, zinc, manganese, and iron in CCCLE than OVCLE in mg/100 g. Similarly, the vitamin A, C and E content were highest in CCCLE than OVCLE in mg/g. The inhibitory concentration at fifty percent (IC50) values on the effect of aqueous extracts of OVCLE and CCCLE on DPPH scavenging activity showed that CCCLE (IC50=131.8 µg/mL) had the higher activity than OV (IC50=154.1 µg/mL) as compared to the standard, Ascorbic Acid (IC50=49.13 µg/mL). The crude aqueous extract of C. citratus and O. vulgare harvested from Zaramaganda, Jos, North-Central Nigeria are good source of Vitamins (A, C and E), Potassium, Sodium, Calcium, Zinc and little of Manganese and Iron, also with good moisture content, ash content, crude fibre, lipid content and crude fat values. Furthermore, both plants were moderate in reducing DPPH radical levels and thus suggested for cancer patients.

Quaternary nanorods: promising versatile agents for cancer therapy, antimicrobial strategies and free radical neutralization

Cu2XSnS4 (CXTS; X: Zn, Mn or Co) nanorods (NRs) were prepared by a simple hot-injection method and their cytotoxic activities on human breast adenocarcinoma (MCF-7), metastatic melanoma (451Lu) and embryonic kidney (HEK-293) cell lines were investigated for the first time. The antibacterial activities of these nanoparticles on both gram-positive (S. aureus) and gram-negative (E. coli) pathogenic bacteria as well as their DPPH (2,2-diphenyl-1- picrylhydrazyl) scavenging activities were evaluated. The structural characterizations show that the obtained nanoparticles have the same crystal structure and are shaped as nanorods with an average 10–40 nm edge length. The data obtained in cytotoxicity studies revealed that the synthesized CXTS NRs have a significant inhibition effect, especially on cancer cell lines (MCF-7 and 451Lu), in a dose-dependent manner over a period of 24 h, demonstrating their potential for use as anticancer agents. In addition, the findings indicate that the synthesized nanorods possess strong antibacterial properties against the pathogenic microorganisms tested and display a marked antioxidant effect through efficient elimination of DPPH activity. This comprehensive study sheds light on the creation and development of CXTS NRs as promising versatile agents in various biomedical and environmental applications such as cancer therapy, antimicrobial strategies and the neutralization of free radicals.

Antioxidant and Antimicrobial Activity of a Medicinal Mushroom, Ganoderma lucidum

This study aimed to evaluate the antioxidant and antimicrobial activity, along with the determination of major fatty acids by GC-MS and the content of total phenolic compounds of Ganoderma lucidum naturally grown in Türkiye. The antioxidant activity was determined by widely used DPPH radical scavenging method. G. lucidum methanol extract exhibited a 90.81% scavenging activity of DPPH. The content of total phenolic compounds was determined as 235.19 µg GAE/mL by Folin-Ciocalteu’s phenol reagent method. The major fatty acids of G. lucidum were characterized by GC-MS. 2,6-di(t-butyl)-4-hydroxybenzoic acid (RT: 30.021 min), hexadecanoic acid (RT: 36.221 min), 9,12-octadecadienoic acid (RT: 39.949 min), 9-octadecenoic acid (RT: 40.076 min) and octadecanoic acid (RT: 40.601 min) were found to be the predominant fatty acid compounds. The methanol and acetone extracts of G. lucidum were also tested against pathogenic microorganisms via agar disc diffusion method and exhibited various levels of inhibition. The highest antimicrobial activity was detected as 17.67±0.47 mm against Enterococcus faecalis ATCC 29212 strain by acetone extract.

Insight into the effect of synthesis parameters on the properties of graphene quantum dots for theranostic application

Ultra-small size and tunable optical properties of graphene quantum dots (GQDs) make them potentially suitable for theranostic applications. This investigation focuses on the effect of process parameters for the synthesis of GQDs of desirable optical properties for biomedical applications. The effect of the raw materials (graphene oxide sheets, glucose, and starch), reaction temperature (170 to 200 °C), and reaction time (3 to 6 h) was investigated on GQDs prepared through hydrothermal treatment. The dispersion of GQDs was characterized using dynamic light scattering (DLS), UV–visible, fluorescence, Raman, and X-ray photon spectroscopic techniques. The effect of the solution temperature and pH on the fluorescence properties of GQDs was also studied. The small hydrodynamic diameter (8.57 ± 1.47 nm) was observed with GQDs prepared from glucose using hydrothermal treatment time of 4 h at 190 °C (GQDs-D). The GQDs-D showed blue fluorescence (λem= 460 nm) with a quantum yield (QY) 67.09 ± 1.25%. The fluorescence characteristic of the GQDs was unchanged up to 6 months during storage at room temperature. GQDs-D revealed their antioxidant nature with a DPPH scavenging activity of 15.08 ± 2.07%. Despite having relatively low DPPH scavenging activity, excellent hemocompatibility (0.23 ± 0.04%) and colloidal stability against bovine serum albumin (BSA) showed GQDs-D as a safe nanocarrier for theranostic application. This was further substantiated with circular dichroism (CD) spectroscopy, which exhibited a preserved α-helical structure of BSA by GQDs-D. High-resolution transmission electron microscopic image of GQDs-D showed an average particle size of 5.70 nm and homogeneous particle distribution between 2–8 nm. Conclusively, all the results revealed the potential of GQDs-D for theranostic application.

Influence of Epilobium parviflorum Herbal Extract on Physicochemical Properties of Thermoplastic Starch Films.

In this study, for the first time, Epilobium parviflorum Schreb. (E, hoary willowherb) aqueous extract was introduced into edible biopolymer films and its influence on physicochemical properties of the final products were investigated. Potato starch was gelatinized in the herbal tea to obtain thermoplastic starch (TPS) films via the casting method. The characterization of the films included mechanical, antioxidative, water (WVTR, contact angle, swelling degree) and UV radiation barrier properties as well as microstructure analysis (SEM). Obtained results indicated that the presence of the extract (rich in phenolic compounds) in the films acted as a co-plasticizer for starch and led to a higher elongation at break, up to 70%, with a parallel increase in tensile strength up to ca. 9 MPa. Moreover, TPS films with E exhibited lower WVTR values and absorption of UV light in comparison with the control TPS film. DPPH scavenging activity of TPS E films immersed in methanol was ca. 92%, and it was related to the release of the extract into liquid media. Novel TPS E films are characterized by multifunctional properties that can be used, e.g., in the active packaging sector.

Physical Properties Investigation on Sunscreens with Red Dragon Fruit Peel Extract

Red dragon fruit peel extract is reported as an active ingredient in sunscreen because of its ability to protect the skin. UV exposure to the skin can cause reddish skin to develop skin cancer. This study aimed to determine the characteristics of the cream made from ZnO and red dragon fruit peel extracts (Hylocereus costaricensis), such as sun protection factor (SPF), pH, stability, viscosity, spreadability, and adhesion. Red dragon fruit peel extract was obtained by maceration using methanol, and DPPH-scavenging activity resulted in an IC50 of 0.96 μg/mL. Measurement of diffuse UV-vis reflectance shows that ZnO has absorption at λex 385 nm, which correlates with a bandgap energy of 3.22 eV. F1 formulation cream (red dragon fruit peel extract and ZnO ratio of 0:1) has the highest SPF value of 17. The Kruskal-Wallis test shows that there is a significant difference in adhesion between the F1 formulation cream with F2 (p-value = 0.002) and F4 (p-value = 0.03).

DPPH Scavenging Activity, Reducing Power, and Metal Chelating Capacity of Compound 1-(2,5-dihydroxyphenyl)-3-pyridine-2-yl-propenone

Background: The excessive free radicals in the body could stimulate oxidative stress which has been implicated in several diseases such as cancer, inflammation, aging, and cardiovascular diseases. The presence of antioxidants can diminish the reactivity of free radicals. The antioxidant defense system in the body may be insufficient thus intake of dietary antioxidants is recommended. Natural flavonoid such as chalcone has been known to exert several biological activities, especially antioxidant activity. Compound 1-(2,5-dihydroxyphenyl)-3-pyridine-2-yl-propenone was successfully synthesized using microwave radiation and several studies reported its biological activities such as antiinflammation, anticancer, and antibacterial activities. Those activities are thought to be related to antioxidant mechanisms. Therefore, this study aimed to evaluate its antioxidant activity. Methods: The antioxidant activities were performed with three different methods: DPPH scavenging activity, ferric reducing power, and metal chelating capacity. Results: 1-(2,5-dihydroxyphenyl)-3-pyridine-2-yl-propenone showed DPPH scavenging activity, ferric reducing power, and metal chelating capacity with IC50S values of 4,471 ± 0,052 μg/mL; 156.56 ± 4.42μg/mL; and 6,273 ± 0,025 μg/mL, respectively. Conclusions: Our results found that 1-(2,5-dihydroxyphenyl)-3-pyridine-2-yl-propenone had quite potent antioxidant activity.

Study of the Antioxidant Capacity and Oxidation Products of Resveratrol in Soybean Oil.

Resveratrol (3,5,4'-trihydroxystilbene), a naturally occurring polyphenol that is widely utilized in functional food due to its antioxidant, anti-inflammatory, anti-cancer and anti-aging properties. In the present study, the antioxidant capacity and oxidation products of resveratrol in soybean oil were investigated. The antioxidant activity of resveratrol was evaluated by employing various in vitro antioxidant assays such as DPPH scavenging activities, ferric reducing abilities (FRAP) and oxygen radical absorbance capacity (ORAC). Furthermore, monitoring the peroxide value and the acid value of soybean oil with the addition of 200-1000 μg/g of resveratrol at 60 and 180 °C. It was found that when the concentration of resveratrol in soybean oil was 600 µg/g, the antioxidant capacity was most effective. Resveratrol and its thermal degradation products were identified using liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS). There were seven nonvolatile oxidation products with mass-to-charge ratios of 138.03, 171.04, 185.10, 157.03, 436.13, 244.07 and 306.09 kg/C and two volatile oxidation products with mass-to-charge ratios of 100.05 and 158.13 kg/C were identified. The research findings may provide essential information for the development of resveratrol as functional oils in future.

Fermented Syzygium samarangense leaves mitigate oxidative stress-triggered hepatotoxicity through Nrf2 activation and epigenetic regulation

The liver, which is a vital organ for metabolism and detoxification, is susceptible to damage caused by oxidative stress. Excessive consumption of acetaminophen (APAP), a commonly used analgesic ingredient, can cause liver injury due to oxidative stress. The aim of this study is to examine the protective effects and mechanisms of fermented Syzygium samarangense (wax apple) leaves (FWAL) against damage caused by APAP in mouse AML-12 hepatocytes. Ethanolic and water extracts of FWAL (FWAL-EE and FWAL-WE) were prepared, and both contained significant phenolic compounds such as gallic acid, EGCG, ellagic acid, myricitrin, and myricetin, with potent DPPH scavenging activity. FWAL-EE demonstrated superior effectiveness in lowering the death ratio, LDH leakage, and oxidative stress in APAP-treated AML-12 cells. The protective effects of FWAL-EE included the downregulation of inflammatory markers TNF-α and cox-2 mRNA, as well as the upregulation of Nrf2, HO-1, and NQO1 proteins in APAP-treated hepatocytes. Additionally, FWAL-EE reduced the expression of epigenetic enzymes HDACs 1, 2, 3, and 4, and DNMTs 1 and 3b while causing an increase in unmethylated DNA levels in the Nrf2 promoter region. Furthermore, EGCG, a prominent active compound in FWAL, protected AML-12 hepatocytes from APAP-induced damage by activating Nrf2 and NQO1, while also inhibiting epigenetic DNMTs and HDACs. These results suggested that FWAL-EE may effectively prevent APAP-induced liver damage by enhancing the activation of the Nrf2 antioxidant system through epigenetic regulation. FWAL-EE has potential as a nutraceutical for liver protection.

Galanthus elwesii Hook.f.’nin Farklı Ekstraktlarının Serbest Radikal Yakalama ve Metal Şelatlama Aktivitelerinin Tespit Edilmesi

Natural compounds play an important role among antioxidants that protect the human body against oxidative stress. Many plants may have high levels of antioxidant capacity through the compounds they contain. In line with this information, in the current study, we aimed to evaluate the antioxidant properties of Galanthus elwesii Hook.f. In this context, we tested the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and metal chelating activities of different concentrations (12.5-400 mg/L) of methanol and water extracts obtained from the bulb part of this plant. A concentration-dependent increase in activity was observed for both extracts. DPPH scavenging (87.10%) and metal chelating (72.99%) activities demonstrated by 400 mg/L concentration applications came to the fore. In addition, it was determined that these data were significantly (p < 0.05) higher than the activity rates revealed by other applications. Considering the IC50 values, low values for DPPH scavenging and metal chelating activities (110.88 mg/L and 132.40 mg/L, respectively) were detected in water extracts. As a result, the importance of G. elwesii among plants that have the potential to be a rich source of antioxidants was revealed in this study.

Structural, rheological properties and antioxidant activities analysis of the exopolysaccharide produced by Rhizobium leguminosarum bv. viciae VF39

Microbial exopolysaccharide is an eco-friendly and non-toxic biopolymeric materials widely used in various industrial fields such as pharmaceutical, food and cosmetics based on its structural, rheological and physiochemical properties. A microbial exopolysaccharide (VF39-EPS) was directly isolated from Rhizobium leguminosarum bv. viciae VF39. Structural analysis using FTIR and 2D NMR spectroscopy confirmed the complete chemical structures of VF39-EPS as 3-hydroxybutanoylglycan with octasaccharide repeating units containing two pyruvyl, two acetyl, and one 3-hydroxybutanoyl group. VF39-EPS exhibited thermal stability up to 275 °C and showed characteristic rheological behaviors of structural fluid with weak gel-like properties above 4 % the aqueous solution, suggesting VF39-EPS as a potential effective thickener or hydrogel scaffolder. Flow behavior tests validated broad stability at a wide range of both pHs from 2 to 12 and temperatures from 25 to 75 °C, and even in the presence of various salts. Furthermore, VF39-EPS showed excellent antioxidant effects of 78.5 and 62.4 % (n = 3, p < 0.001) in DPPH scavenging activity and hydroxyl radical scavenging activity, respectively. Therefore, those structural, rheological and antioxidant properties suggest that VF39-EPS could be one of the excellent biomaterial candidates for cosmetic, food and pharmaceutical industries based on its characteristic rheological behaviors in various condition and excellent antioxidant activity.

Encapsulation of Leptadenia pyrotechnica (Khip) Extract in Carbomer Based Emulgel for Its Enhanced Antioxidant Effects and Its In Vitro Evaluation.

The use of natural products in skin care has been valued for their tremendous therapeutic benefits since ancient times. The current study was aimed at exploring the Leptadenia pyrotechnica plant extract and development of a stable emulgel loaded with the same extract to assess its cosmeceutical potentials. A stable emulgel loaded with methanolic plant extract along with its control gel was prepared by homogenization. The antioxidant potential of extracts prepared in different solvents (methanol MLP, ethanol ELP, n-hexane nLP, ethyl acetate EALP, and petroleum ether PLP) was determined by DPPH scavenging activity. The presence of phytochemicals was confirmed by total phenolic and flavonoid content analysis (TPC/TFC). HPLC was used for quantification of bioactive components. FTIR analysis was performed for confirmation of functional groups. SPF was calculated via spectroscopic analysis for extract, control gel, and extract loaded emulgel. Stability studies included physical evaluation, pH, conductivity, spreadability, and rheological testing of both control and test emulgels at different temperatures, i.e., 8 °C ± 1, 25 °C ± 1, 40 °C ± 1, 40 °C ± 1 with RH of 75% for a period of 90 days. DPPH radical scavenging activity showed the highest antioxidant activity of 85.5% ± 2.78 for MLP. TPC and TFC were also found to be highest for the methanolic fraction, i.e., 190.98 ± 0.40 mgGAE/g and 128.28 ± 2.64 mgQE/g, respectively. The SPF of methanolic extract, placebo gel, and LPEG was 13.43 ± 0.46, 2.37 ± 0.33, and 7.28 ± 0.56, respectively. HPLC assay confirmed the presence of catechin, vanillic acid, caffeic acid, and sinapinic acid. Rheological analysis showed that formulation has pseudo-plastic flow behavior. Other stability tests also revealed that prepared emulgel is a stable one. A stable emulgel loaded with Leptadenia pyrotechnica plant extract was successfully prepared and characterized for its cosmetic effects.

Uric acid–reducing efficacy of Plectranthus amboinicus (Lour.) Spreng in mice with potassium oxonate-induced hyperuricemia

Plectranthus amboinicus (Lour.) Spreng is a type of Lamiaceae perennial herb that is widely used in folk treatments for respiratory and skin diseases. Notably, research on the hypouricemic effect of P. amboinicus is limited. This study investigated the uric acid–reducing efficacy of P. amboinicus in mice with potassium oxonate-induced hyperuricemia by performing an in vitro xanthine-oxidase-inhibition-activity-guided test of P. amboinicus extract (PAE) and its fractions. The ethyl acetate fraction (EAF) of PAE exhibited optimal efficacy in terms of the phenolic content, DPPH scavenging activity, and xanthine oxidase inhibition. We further demonstrated the uric acid–reducing activity of EAF in a mouse model of potassium bromate–induced hyperuricemia. The results can serve as a useful preclinical reference for researching the gout prevention effects of functional foods.&#x0D; Keywords: Plectranthus amboinicus (Lour.) Spreng, hyperuricemia, uric acid–reducing activity