Percentage Of Antioxidant Activity Research Articles

Chemical profile and biological potential of essential oil of Psidium bahianum Landrum & Funch (Myrtaceae).

The genus Psidium, belonging to the family Myrtaceae, encompasses several plant species rich in essential oils. Several studies involving different research areas have shown promising results for essential oils, which has attracted interest from diverse sectors, including pharmaceutical, food, and cosmetic industries. Thus, the objective of this study was to evaluate the biological activity of the essential oil extracted from Psidium bahianum leaves (EOPb) collected in an Atlantic Forest remnant in the northern coast of the state of Bahia, Brazil. EOPb was extracted by steam distillation and analyzed through proton nuclear magnetic resonance (1H-NMR). The free radical scavenging activity was assessed using the DPPH methodology (analyzing the scavenging of the stable free radical 1,1-diphenyl-2-picrylhydrazyl). Antimicrobial disk diffusion assays were conducted; toxicity was determined through assays on sheep erythrocytes and Artemia salina. 1H-NMR evaluation showed the presence mainly of monoterpenes and sesquisterpenes. The percentage of antioxidant activity was 18.03±2.53 53 for 125 125 µg mL-1. Antimicrobial assays showed that the essential oil at a concentration of 10 mg mL-1 inhibited the growth of the microorganisms Staphylococcus aureus, Bacillus subtilis, B. cereus, Micrococcus luteus, Escherichia coli, Aspergillus niger, Candida albicans, and C. glabrata. The toxicity results indicated that concentrations of EOPb at 10, 100, 250, and 500 µg mL-1 were not toxic to sheep erythrocytes. The toxicity assay on A. salina showed that the lethal concentration for 50% of individuals (LC50) within 24 and 48 hours were 371.48 and 302 µg mL-1 of EOPb, respectively, which were considered moderately toxic, whereas the LC50 within 72 horas was 33.11 µg mL-1, considered highly toxic. These findings are promising, as the essential oil from P. bahianum leaves showed antimicrobial activity against both Gram-positive and Gram-negative bacteria and fungi. The data obtained for the essential oil toxicity in A. salina could be tested on different tumor cell lines.

Influence of green pepper extract on the physicochemical, antioxidant, and sensory properties of stirred yogurt

The green pepper has garnered interest in different societies as a functional food and food additive. Numerous studies have indicated that the phytochemicals found in pepper possess antioxidant, anti-cancer, anti-inflammatory, anti-obesity, and anti-arteriosclerotic properties. In this study, green pepper extract was used in yogurt to increase the acceptability of consumption and improve its health properties. For this purpose, green pepper extract was added in concentrations 100, 200, and 300 ppm in the preparation of yogurt. And pH, acidity, total content of phenolic compounds, DPPH inhibition percentage, viscosity, syneresis, and sensory properties were evaluated in 1, 7, 14, and 21 days after production. The results showed that by increasing the amount of extract, the percentage of antioxidant activity and phenolic compounds increased significantly. The effect of storage time on these indicators was also significant (p < 0.05). in such a way that over time, there was a decrease in antioxidant activity. But, there was a slight increase in antioxidant activity on the 14th day of storage. Also, the effect of treatment type on some physicochemical characteristics of yogurt containing green pepper extract including pH, acidity, viscosity, and syneresis was significant (p < 0.05). During storage, acidity, syneresis, and viscosity increased and pH decreased significantly in all yogurt samples. Regarding the tested sensory attributes, the 200 ppm sample received the highest score among the evaluators, and in terms of overall acceptance, the samples containing the extract were more favorable than the control sample.

Development of ascorbyl palmitate-loaded nanostructured lipid carriers (NLCs) to increase the stability of Camelina oil

In this study, ascorbyl palmitate (AP) incorporated in nanostructured lipid carriers (NLCs-AP) was fabricated using the hot-homogenization method. The amounts of AP, Tween 80, glyceryl stearate, and oleic acid were optimized by Box-Behnken Design (BBD) to obtain a high percentage of encapsulation efficiency and loading efficiency. Then, the optimum NLCs-AP, free-AP with rosemary essential oil (REO), NLCs-AP with REO, and tert-Butylhydroquinone (TBHQ) at a concentration of 75 ppm were added to camelina oil. Then peroxide value (PV), anisidine value (AV), TOTOX value (TV), oxidative stability using Rancimat, total phenol content (TPC), and antioxidant activity in camelina oil samples were evaluated during 90 days of storage at the ambient temperature. The optimum NLCs-AP had a particle size of 133.4 nm and a PDI of 0.29. The transmission electron microscopy (TEM) showed a spherical and smooth surface of the optimum NLCs-AP. The results of differential scanning calorimetry (DSC) and Fourier transfer spectroscopy infrared (FTIR) analyses implied that there was no interaction between AP and NLCs. The Korsmeyer-Peppas model was the best model for the evaluation of the release kinetics. The amounts of PV, AV, and TV of camelina oil containing the optimum NLCs-AP were slightly higher than the oil containing TBHQ. The highest oxidative protection, TPC, and antioxidant activity percentage were achieved in camelina oil containing NLCs-AP with REO. Conclusively, the optimum NLCs-AP had excellent potential for encapsulation of AP, and the mixture of REO and NLCs-AP could be applied for giving suitable oxidative stability in camelina oil.

Chemical Profile and Biological Potential of Hornodermoporus martius (Agaricomycetes) from Paraguay.

To further knowledge of the biological activity of native neotropical fungal species, this study aimed to determine the chemical composition and microbiological activity of Hornodermoporus martius. Ethanol, hexane, diethyl ether, and ethyl acetate fractions and the water residue were analyzed and resulted in a total phenolic compound content between 13 and 63 mg of gallic acid equivalents per gram of crude extract. The total antioxidants ranged between 3 and 19 mg of ascorbic acid equivalents per gram of crude extract, and the percentage of antioxidant activity was determined to be between 6 and 25%. A preliminary profile of compounds is provided for the first time for the species; the results from the nonpolar fraction showcased the presence of saturated and unsaturated acids, fatty alcohol, sterols, and cis-vaccenic acid. Our findings also revealed antimicrobial properties from compounds within the hexane and diethyl ether fractions at concentrations of 1 mg mL-1, which inhibited the growth of certain gram-positive and gram-negative bacteria. For the first time in academic literature, our work analyzed and documented the chemical characteristics and microbial properties of H. martius, suggesting potential for medicinal applications.

Formulation of nanoemulsion carriers containing Pennyroyal (Mentha pulegium) and Gijavash (Froriepia subpinnata) essential oils for enriching Doogh (Iranian dairy drink).

Today, the increasing use of chemical preservatives in foods is considered one of the main problems in food industries. This study aimed to produce the pasteurised Doogh (Iranian yogurt drink) containing a nanoemulsion of essential oil (EO) with appropriate quality. A factorial test based on a completely randomised design with two treatments in three levels, including EO type (pennyroyal, Gijavash, and their equal combination) and a control sample was applied to assess the physicochemical and sensory properties of Doogh. The highest negative zeta potential and antioxidant activity percentage were observed in the sample containing the nanoemulsion of pennyroyal and enriched with a combination of two essential oils. The microbial evaluation results indicated that the total microorganism count was minimised in the Doogh containing the nanoemulsion of Gijavash. The nanoemulsions of pennyroyal and Gijavash can be added into Doogh formulation to produce a new product with maximum sensory acceptability.

Antioxidant Activity Test Of Water, Ethyl Acetat, And N-Heksan Fraction Of Ethanolic Extract Of Sarang Semut (Myrmecodia Pendens Merr. &amp; Perry)

Sarang Semut (Myrmecodia pendens Merr. &amp; Perry) is a medical plant contains of flavonoids, tannins, phenolic compounds, polyphenols, and vitamin E. Those substances are potent antioxidants. This research refers to previous research that the ethanol extract of Sarang Semut (Myrmecodia pendens Merr. &amp; Perry) provided antioxidant activity with a mean EC50 of 3.8021 µg/ml. The purpose of this research was to determine the antioxidant activity of the fractions of ethanolic extract of Sarang Semut (Myrmecodia pendens Merr. &amp; Perry) and to determine the highest antioxidant activity of them expressed by EC50. Sarang Semut (Myrmecodia pendens Merr. &amp; Perry) was extracted by soxhletation method using 96% ethanol solvent, then the ethanolic extract partitioned by liquid-liquid fractionation with water, ethyl acetate, and n-hexane. Each fraction at a concentration of 0.9 µg/ml, 1.0 µg/ml, 2.0 µg/ml, 3.0 µg/ml, 4.0 µg/ml, and 5.0 µg/ml were tested by the DPPH method (1,1-diphenyl-2-picrylhidrazyl ) using a spectrophotometer at λ 515 nm and operating time 35 minutes. The result shows the fraction of ethyl acetate has the highest antioxidant activity with a mean EC50 of 2.8821 µg/ml. While the average EC50 fraction of water is 3.8830 µg/ml and n-hexane is 259.9872 µg/ml. From the statistical t test is known that the fraction of water and ethyl acetate have significantly different rates of EC50, while the average of n-hexane fractions were not analyzed statistically because the percentage antioxidant activity of its fraction is not stable.

Cymbopogon citratus Protects Erythrocytes from Lipid Peroxidation in vitro.

Essential oils are complex mixtures of volatile compounds, primarily composed of terpenes and abundant aromatic plants. For example, Cymbopogon citratus (lemongrass) is an aromatic plant that produces a monoterpene-rich essential oil, and studies show that this essential oil has excellent antioxidant activity. Erythrocytes incubated under high sugar levels are constantly exposed to reactive oxygen species, which results in the oxidation of their membranes. The aim of this article is to investigate the antioxidant activity of lemongrass essential oil and its protective effect on erythrocytes exposed to high levels of glucose. The essential oil was obtained by steam dragging distillation; blood cell suspensions were incubated with glucose 5, 20, 50, and 100 mmol/L. The amount of TBARS produced was measured at 532 nm. In addition, the percentage of antioxidant activity was assessed by DPPH free radical assay. Lemongrass essential oil showed an increase in the antioxidant activity up to 240 mg/ml, while ascorbic acid used as positive control showed a dose-dependent increase in antioxidant activity starting at 1 mmol/L up to 18 mmol/L. However, such a lemongrass dose prevented peroxidation in erythrocytes incubated under a high glucose media, whereas ascorbic acid showed a protective effect only at a concentration of 1 mmol/L. Lemongrass essential oil has high antioxidant activity compared to standard antioxidant as ascorbic acid, and also acts as a protective agent against erythrocyte lipoperoxidation due to hyperglycemia in vitro.

Comparative Physicochemical, Microbiological, Antioxidant, and Sensory properties of pre- and post-fermented yoghurt enriched with olive leaf and its extract.

This study investigated the comparative effect of yoghurt samples enriched with different concentrations of olive leaf powder (OLP) (0.1, 0.5, 1, and 1.5 mg/ml) and its extract (OLE) (0.5, 1, 3, and 5 mg/ml) on the microbiological, sensory, physicochemical, and antioxidant properties of pre‐ and post‐fermented samples during 21 days of storage. Sensory evaluation showed that concentrations lower than 1.5 and 5 mg/ml of OLP and OLE, respectively, were acceptable. Adding OLP or OLE did not have an influence on yoghurt starter culture bacteria (p > .05). All enriched samples significantly showed higher acidity and lower pH compared with control samples (p < .05). The most important polyphenols were oleuropein (from 0.132 to 0.224 and 0.373 to 0.413 mg/g for 0.5 and 3 mg/ml of OLE, from 0.194 to 0.321 mg/g and 0.413 to 1.280 mg/g for 0.5 and 1 mg/ml of OLP, respectively) and catechin (from 0.369 to 0.382 and 0.461 to 0.477 mg/g for 0.5 and 3 mg/ml of OLE, from 0.386 to 0.405 mg/g and 0.310 to 0.710 mg/g for 0.5 and 1 mg/ml of OLP, respectively) in enriched yoghurts. Adding OLP or OLE increased shelf life, antioxidant activity percentage (AA%), and total phenol content (TPC) of enriched samples (p < .05). During 21 days of storage of all samples, TPC, AA%, and pH decreased and TTA increased.

Synthesis and Characterization of Chitosan/Silver Nanocomposite Using Rutin for Antibacterial, Antioxidant and Photocatalytic Applications

The present study reports an eco-friendly synthesis of chitosan/silver (CS/Ag) nanocomposite using rutin by a bio-inspired method. The formation of brown color and UV–visible absorbance peak at 415 nm confirmed the synthesis of CS/Ag nanocomposite. X-ray diffraction (XRD) analysis revealed the crystalline peaks of both chitosan and silver in synthesized CS/Ag nanocomposite. Field emission-scanning electron microscopy (FE-SEM) analysis showed that the synthesized CS/Ag nanocomposite having predominant spherical shaped nanostructure with an average size of 23–78 nm. Fourier transform infrared spectroscopy (FTIR) analysis indicated the presence of functional derivatives related to chitosan and rutin in CS/Ag nanocomposite. Synthesized CS/Ag nanocomposite exhibited superior disc diffusion antibacterial activity against Bacillus subtilis and Escherichia coli. The in vitro antioxidant of CS/Ag nanocomposite was evaluated spectrophotometrically by using DPPH method. The percentage of antioxidant activity was increased with increasing concentration of CS/Ag nanocomposite. Furthermore, photocatalytic activity of CS/Ag nanocomposite was evaluated by the removal of methylene blue (MB) dye from aqueous solution under sunlight irradiation. Results showed that the degradation efficiency of MB reached up to 88% after irradiation for 220 min. Thus, the obtained results indicated that the synthesized CS/Ag nanocomposite using rutin can be a promising nanomaterial for multifunctional applications.

Comparison of efficacy of nanoparticles synthesized from leaves and flowers of Russelia equisitiformis

The present study was focused on synthesis of silver nanoparticles using Russelia equisitiformis plant (RelAgNps) and flower extracts (RefAgNps). Thus, the nanoparticles synthesis was confirmed using UV spectrometry and the FT-IR results showed the presence of similar compounds in the plant extract and FESEM-EDAX reveals the size, shape, and elemental composition of synthesized nanoparticles. The antioxidant activity of the RefAgNps from flower extract and RelAgNps from leaf extract was observed at the concentration of 25 μg/mL but the percentage of antioxidant activity of flower extract was comparatively higher than the leaf extract. This plant is also known to have antidiabetic activity and thus leaf extract and flower extract mediated nanoparticles is also known to have alpha amylase inhibition activity at the concentration of 12.5 and 100 μg/mL, respectively. Molecular docking of the plant compounds10-O-cinnamoyl sinuatol and rehmaglutin B were docked with alpha amylase enzyme proves the same with the binding energy of −9.1 kcal/mol. Thus, to the best of our knowledge this is the first-time nanoparticles have been synthesized using R. equisitiformis flower and leaf extract and observed to have potent antioxidant and antidiabetic activity.

A study of antioxidant and antibacterial activity using honey mediated Chromium oxide nanoparticles and its characterization

Honey is authenticated as the world’s prehistoric food source with incomparable therapeutic, biochemical, physical, and curative values. Chromium oxide nanoparticles were precipitously generated by reduction of potassium dichromate solution in collaboration with natural honey holding carbohydrates as a chief component which perform as reducing agent. The outcome suggests that water soluble carbohydrates have aldehyde group cause the formation of Cr2O3 nanoparticles. The properties of the prepared Cr2O3 nanoparticles were characterized using several techniques such as UV–Visible, FT-IR, SEM, EDAX, XRD and AFM. The FT-IR studies reveals that the broad band of low intensity at 1165.00 cm−1 can be found to be the surface Cr-O stretching vibrations. The SEM image illustrates the rocky structure of the prepared nanoparticle. The AFM image exhibits the topography of Cr2O3nanoparticles in 3.13 µm resolution for 2D and 3D view with current passing over the probe with the scanning area of 9.842 pm2. The XRD result concludes the average size of Cr2O3 nanoparticles as 24.7205 nm. The antioxidant study shows the fluctuation in percentage of antioxidant activity as the concentration varies. The antibacterial activity explains clearly that the prepared sample has zone inhibition with the 3 pathogens studied. Thus the honey medicated nanoparticle synthesis provides a simple, cost effective, reproducible, rapid, and safe method with numerous applications.

English

This study aims to screen possible antioxidant potentials of methanol extract and polar fractions of Vernonia calvoana leaves and its phytochemical constituents since the leaves are used ethno medically in managing ailments like wounds, blood pressure, inflammation, arthritis, and bone diseases. Dried leaves (900 g) were ground and de-fatted with n-hexane. The dry marc was extracted using 80% methanol and water. Filtrate was concentrated using rotary evaporator at 40°C. Acute toxicity study and phytochemical analysis were performed with crude extract. Fractionation of crude extract using gradient concentrations of methanol and distilled water yielded 4 fractions - F1, F2, F3 and F4. Fractions with the crude were used for in vitro antioxidant studies. From the results, crude extract showed no signs of toxicity in mice at 2000 mg/kg orally. Phytochemical screening showed presence of alkaloids, flavonoids, tannins, phenols, steroids, saponins, terpenes, arthroquinones, carbohydrates and glycosides. The highest percentage antioxidant activity observed with crude extract was 72.37 at 500 µg/ml in DPPH spectrophotometric assay. DPPH results showed percentage antioxidant activity of 81.4% at 500 µg/ml of F1 and 67.73% at 500 µg/ml of F2. The FRAP values of the crude extract, F1, F2, F3 and F4 at 500 µg/ml were 1.957, 2.234, 1.731, 1.245 and 1.025 µM respectively. These results showed that the activities of methanol extract of leaves of V. calvoana may be dependent on the concentration of the extracting solvent. Vernonia species are known to contain abundant saponins and flavonoids which are polar compounds and readily soluble in methanol. This may explain the above observed antioxidant activities and thus, the use of the leaves in different traditional curative therapies in Southern Nigeria. Key words: Vernonia calvoana, leaves, antioxidants, crude extract, phytochemicals.

The Antioxidant Activity Components Change of Pears Subject to Static and Dynamic Loads

ABSTRACT The present research investigated the effect of static and dynamic loading in various storage periods on the amounts of pears’ components like total phenol content, DPPH radical scavenging activity, and Vitamin C amount. in this investigation was subjected to static loading (thin-edge and wide-edge compression) using three different force and for dynamic loading using three weights in three different storage periods. Next, the total phenol content, percentage of antioxidant activity and vitamin C were measured. The results showed that the total phenol content, DPPH radical scavenging activity, and vitamin C rates were decreased with increasing force and weight loading and also with increasing storage period the amount of components were decreased. The amount DPPH radical scavenging activity, phenol compound and vitamin-C for control sample were 54.36%, 32.5 mg GAE/100 g and 8.3 mg/100Fw respectively, Also for wide loading and thin loading this amount was 35.56 and 37.56%, 13.11 and 21.29 mg GAE/100 g and 5.76 and 6.33 mg/100Fw respectively, For dynamic loading was 25.015%, 11.37 mg GAE/100 g and 5.82 mg/100Fw respectively. In general, the highest amount for the total phenol content, DPPH radical scavenging activity, and vitamin C obtained in thin-edge loading, also the wide-edge and dynamic loading had more effect on decreasing phenol and vitamin-C in pear during storage.

Avaliação quantitativa de atividades antioxidantes das plantas nativas da Região do Alto Oeste Potiguar/RN

No Brasil o conhecimento popular acerca das plantas com ações medicinais é motivo para diversas investigações envolvendo variadas espécies vegetais. Dentre os estudos realizados com extratos de plantas, há um interesse especial na atividade antioxidante, que atua inibindo e/ou diminuindo os efeitos desencadeados pelos radicais livres e compostos oxidantes. Diante dessa perspectiva, o presente trabalho avaliou a ação antioxidante de extratos etanólicos das espécies: Pereiro (Aspidosperma pyrifolium Mart), Juazeiro (Ziziphus joazeiro Mart), Catingueira (Caesalpinia pyramidalis Tui), Jurema Preta (Mimosa tenuiflora Willd) e Ameixa Selvagem (Ximenia americana L.) nativas da região do Alto Oeste Potiguar, no Rio Grande do Norte. A coleta das folhas e caules foi realizada no sítio Barro Vermelho, município de São Francisco do Oeste (RN), para obtenção dos extratos. Em seguida, eles foram submetidos a testes de atividade antioxidante utilizando o radical livre DPPH. Todas as amostras analisadas demonstraram uma boa porcentagem de atividade antioxidante em suas diferentes concentrações, destacando-se o EEFA, que teve o maior percentual de atividade antioxidante na menor concentração. Assim, sugere-se que a partir desses dados, essas espécies podem apresentar finalidade medicinal conforme conhecimento popular.

Antioxidant Activity of Avicennia alba Blume, (1826) Family Avicenniaceae, Leaf Extracts Using DPPH Assay

The antioxidant activity of Avicennia alba Blume, (1826) leaf extract was determined using 1,1-Diphenyl-2-picrylhydrazyl (DPPH) Free Radical Scavenging Activity Assay. Petroleum ether and 95 % ethanol were used as solvents in two separate macerations. Only the ethanolfree extract (TSB) exhibited antioxidant activity; it showed a color change from purple to light yellow similar to positive control (ascorbic acid solution) and a decrease in absorbance relative to negative control (95% ethanol). The results of the DPPH free radical scavenging activity assay was subjected to statistical analysis using one way ANOVA then post hoc analysis results of TSB showed no significant difference vs positive control, a percentage antioxidant activity of 68.24% ± 12.23 and 76.43% ± 9.22 respectively. The ethanol-free extract (TSB) underwent phytochemical screening by test tube method where it revealed the presence of saponins, tannins, flavonoids, and glycosides. It was then subjected to column chromatography for partial purification of its chemical compounds; fractions from the eulates were collected and were pooled according to their TLC profile specifically Rf values. The fractions that showed significant spots under UV light were fractions 1 and 2; and fractions 4 and 5. These two sets of fractions were tested to DPPH free radical scavenging assay. Both fractions showed similar color change as the positive control and a decrease in absorbance relative to the negative control. Fractions 1&amp;2 showed 69.97% ± 2.439 percentage antioxidant activity which had no significant difference to the positive control with the highest antioxidant activity of 87.88% ± 3.357 .The p-value (&lt;0.01) obtained manifested that there was significant difference between the test solutions with their antioxidant activity. After DPPH assay, the most active fractions 1 &amp; 2, were subjected to FT-IR and GC-MS. Infrared spectrum showed the presence of aliphatic C-H bonds, C=O bond, and –OH bonds while the GC-MS analysis revealed five compounds which were based on the molecular ion showed at m/z = 537.4. The functional groups present in the compounds from FT-IR and GC-MS analyses and the secondary metabolites present in phytochemical screening seemed to be responsible for the antioxidant activity of Avicennia alba leaf extracts.

Antioxidant Activity of Avicennia alba Blume, (1826) Family Avicenniaceae, Leaf Extracts Using DPPH Assay

The antioxidant activity of Avicennia alba Blume, (1826) leaf extract was determined using the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) Free Radical Scavenging Activity Assay. Petroleum ether and 95 % ethanol were used as solvents in two separate macerations. Only the ethanol-free extract (TSB) exhibited antioxidant activity; it showed a color change from purple to light yellow similar to the positive control (ascorbic acid solution) and a decrease in absorbance relative to the negative control (95% ethanol). The results of the DPPH free radical scavenging activity assay were subjected to statistical analysis using one-way ANOVA then post hoc analysis results of TSB showed no significant difference vs positive control, with a percentage antioxidant activity of 68.24% ± 12.23 and 76.43% ± 9.22 respectively. The ethanol-free extract (TSB) underwent phytochemical screening by test tube method which revealed the presence of saponins, tannins, flavonoids, and glycosides. It was then subjected to column chromatography for partial purification of its chemical compounds; fractions from the eulates were collected and pooled according to their TLC profile specifically Rf values. The fractions that showed significant spots under UV light were fractions 1 and 2, and fractions 4 and 5. These two sets of fractions were tested to DPPH free radical scavenging assay. Both fractions showed a similar color change to the positive control and a decrease in absorbance relative to the negative control. Fractions 1&amp;2 showed 69.97% ± 2.439 percentage antioxidant activity which had no significant difference from the positive control with the highest antioxidant activity of 87.88% ± 3.357. The p-value (&lt;0.01) obtained manifested that there was a significant difference between the test solutions with their antioxidant activity. After the DPPH assay, the most active fractions 1 &amp; 2, were subjected to FT-IR and GC-MS. The infrared spectrum showed the presence of aliphatic C-H bonds, C=O bonds, and –OH bonds while the GC-MS analysis revealed five compounds that were based on the molecular ion showed at m/z = 537.4. The functional groups present in the compounds from FT-IR and GC-MS analyses and the secondary metabolites present in phytochemical screening seemed to be responsible for the antioxidant activity of Avicennia alba leaf extracts.

Synthesis and characterization of chitosan/iron oxide nanocomposite for biomedical applications.

The structural and optical properties of metal oxide nanoparticles exhibit remarkable changes when coated with organic polymers. In this work, we report the preparation of chitosan (CS) coated iron oxide nanocomposite using rutin by a facile greener route. The formation of iron oxide nanoparticles (FeO NPs) and CS coated iron oxide nanocomposite (CS-FeO) were preliminarily confirmed by color change and UV-Visible spectroscopy. FE-SEM images of FeO NPs revealed rod shaped agglomerated particles whereas CS-FeO nanocomposite showed rod shaped agglomerated small grains. TEM analysis revealed that the size of the nanoparticles varies from 20 to 90 nm. The observed bands at 500-800 cm-1 in the FTIR spectrum indicated the presence of metal‑oxygen (FeO) bond, whereas band at 1646 cm-1 indicated the presence of amino groups (-NH2) which confirms the CS in the prepared CS-FeO nanocomposite. The prepared nanoparticles showed potential antibacterial activity against both Gram-positive and Gram-negative bacterial pathogens. The antioxidant activity of FeO NPs and CS-FeO nanocomposite was evaluated by DPPH and H2O2 assays. The percentage of antioxidant activity was increased with increasing concentration of FeO NPs and CS-FeO nanocomposite. CS-FeO nanocomposite exhibiting potentially better biomedical property than the uncoated FeO NPs indicates that CS-FeO nanocomposite is a promising bio-nanomaterial for many biological applications.

Evaluation of the Cytotoxic and Antioxidant Activity of Phyto-synthesized Silver Nanoparticles Using Cassia angustifolia Flowers

The present study reports an eco-friendly phyto-synthesis of silver nanoparticles (AgNPs) using aqueous flower extract of Cassia angustifolia. Preliminarily, the synthesis of AgNPs from flower extract was visually confirmed by color change. Further formation, shape, size, and stability of the synthesized AgNPs were characterized by UV-visible spectroscopy, SEM, EDX, XRD, FT-IR, DLS, and zeta potential analyses. SEM images showed that the synthesized AgNPs were spherical in shape with an average size of 10–80 nm. Phyto-chemical analysis and FT-IR studies confirmed the role of phyto-compounds in the flower extract for the capping, formation, reduction, and stabilization of AgNPs. The antioxidant ability of AgNPs and plant extract was evaluated by DPPH, H2O2, and FRAP assays. The percentage of antioxidant activity was increased with increasing concentration of AgNPs. In addition, cytotoxic activity of the AgNPs was evaluated in human breast cancer cells (MCF 7). Phyto-synthesized AgNPs showed dose-depended manner (IC50 − 73.82 ± 0.50 μg/mL) of cytotoxic activity against MCF 7 cancer cells.

In-vitro antioxidant activities of ocimum gratissimum, vitex doniana, carica papaya and peristrophe bicalyculata using DPPH free radical scavenging activity

The ethanol extract of the leaves of Ocimum gratissimum, Vitex doniana, Carica papaya and Peristrophe bicalyculata were assessed for antioxidant activities by the use of 2, 2-diphenyl1-picrylhydrazyl (DPPH) free radical assay. The reducing potentials of these plants were also evaluated. The phytochemical screenings of the medicinal plants were equally carried out. The percentage antioxidant activity values for the plants are: 60.0±1.05%, 60.8±1.28%, 62.4±1.28% and 75.7±2.60% for O. gratissimum, V. doniana, C. papaya and P. bicalyculata respectively. These values were dose dependent and statistically significant at P<0.05 (ANOVA). The results indicated that P. bicalyculata has the highest antioxidant activity value of 75.7±2.60% while O. gratissimum has the least value 60.0±1.05%. The percentage antioxidant activities of the plants were comparable to the standards used, ascorbic acid and α-tocopherol anti-oxidant activities which were found to be 86.7±1.08% and 97.2±1.06% respectively. The reducing potentials of the plants were found to be proportionally correlated to the antioxidant activities of the plants. Phytochemical screenings revealed the presence of flavonoids, saponins, C. glycosides, steroids, alkaloids, tannins, anthraquinones, terpenoids and carbonhydrates in the medicinal plants.

Uji Aktivitas Antioksidan Ekstrak Buah Kluwih (Artocarpus Communis)

This study aimed to determine antioxidant activity of artocarpus camansi fruit extracts from Sigi, Central Sulawesi. This study was conducted by maceration extraction technique, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) as the source of free radicals, and vitamin C as a positive control. UV-Vis spectrophotometer was used for measuring the absorbance of artocarpus camansi fruit extracts. artocarpus camansi fruit powder was extracted by maceration using ethanol. Various concentrations of artocarpus camansi fruit extracts used were 20, 40, 60, and 80 mg/L. The results showed that the IC50 value for artocarpus camansi (artocarpus communis) fruit extract was 88.715 mg/L, whereas the IC50 value for vitamin C was 37.153 mg/L. Artocarpus camansi (artocarpus communis) fruit extracts are powerful antioxidants category based on IC50 value. The optimum percentage antioxidant activity of artocarpus camansi fruit extracts to inhibit free radical amounted to by 50.65%