Synthesis of Silver Nanoparticles Using Flavonoid Hesperidin and Pharmacological Evaluation of its Free Radical Scavenging Activity

Background: Silver Nanoparticles are drawing significant attention from the scientific community to explore a wide range of its medical applications. Human body is under constant stress due to free radicals generated by the physiological and pathological conditions in the body. Scavenging systems or Antioxidants can help alleviate the damages caused by these radicals which can influence the course of progress in several chronic diseases with an inflammatory background. External antioxidants supplement and facilitate the overwhelmed scavenging systems in the body.Silver Nanoparticles can enhance the therapeutic effects of phytochemicals. Aim: To Synthesize silver nanoparticles using the phytochemical Hesperidin and studying its Free radical scavenging activity. Methods: Silver Nanoparticles are synthesized using chemical reduction method. The synthesis is confirmed using spectrophotometric studies. Free Radical scavenging activity is detected using 1, 1-diphenyl-2-picrylhydrazyl (DPPH •) free radical scavenging assay. Results: Silver nanoparticles were successfully synthesized which was confirmed by the change in color of the solution and peak absorbance peak at 420 nM on spectrophotometric studies.Hesperidin Silver Nanoparticles exhibited higher free radical scavenging activity when compared with pure hesperidin and standard Ascorbic acid. Conclusion: Hesperidin can ideally be used for the synthesis of silver nanoparticles and the synthesized Silver Nanoparticles enhances the free radical scavenging activity of Hesperidin which can further be evaluated by In Vivo studies.

A Novel Polyvinylpyrrolidone-Stabilized Illite Microparticle with Enhanced Antioxidant and Antibacterial Effect

Illite is a clay mineral that shows antioxidant and antibacterial activities because of the abundance of important clay elements in its structure. However, illite has low bioactivity due to its low solubility and electron-donating ability in aqueous solutions. Therefore, we aimed to develop polyvinylpyrrolidone (PVP)-stabilized illite microparticles (P-lite MPs) via polymer adsorption on illite surfaces. An increasing amount of PVP was used to coat a fixed amount of illite to prepare P-lite MPs of different hydrodynamic diameters in the range of 4–9 μm. These sizes were maintained for 2 weeks during storage in a biological buffer without any noticeable changes. The stabilization of illite microparticles using a hydrophilic PVP polymer improved their aqueous dispersity and free radical-scavenging activity. Since the large surface area of microparticles provides several sites for interactions, the smallest P-lite MP exhibited the highest antioxidant and antibacterial activities. More importantly, the MPs showed effective free radical-scavenging activity in vitro without any cytotoxicity. Therefore, P-lite MPs with improved bioavailability may represent a suitable bioactive material for various industrial and biomedical applications.

Effects of enzymatic treatment on the chemical composition, antioxidant and rheological properties of cactus cladode juice

Cactus (Opuntia ficus-indica), commonly referred as prickly pear or nopal cactus, belongs to the family Cactaceae. It has attracted domestic and international industries’ attention owing to its nutritional and health benefit potentials. In this project, the quality of the cactus cladode juice after treated with the enzymes Pectinex Ultra SP-L and Viscozyme was investigated in terms of total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity. There were significant increases in the effectiveness of these enzymes as the concentration increased from 0.05 to 0.15% w/w. Among different concentrations, 0.15% w/w produced a higher yield and high-quality juice. Furthermore, the result indicates that prolonging the incubation duration could improve juice yield but this occurred only within the first hour of reaction, which the highest yield was obtained at 0.75 h. At these conditions, the combination of Pectinex Ultra SP-L and Viscozyme at ratio 1:1 (w/w) showed the most effective on juice yield improvement and 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity, while the highest total phenolic content was obtained when treating with Pectinex Ultra SP-L. Particularly as compared to the control sample, the juice yield increased from 53% to 76%, the TPC enhanced from 47 μg gallic acid equivalent (GAE)/mL to 70 μg GAE/mL, and the DPPH free radical scavenging activity improved from 277 μg ascorbic acid equivalent (AAE)/mL to 470 μg AAE/mL. Overall, the quality of cactus juice was better with enzymatic treatment than that of the untreated juice. The data also showed that the cactus juice behaved as shear – thickening fluids at room temperature.

Free radical scavenging activity of five selected sea cucumbers collected from Lampung waters, Indonesia

Sea cucumber is an important raw material for food and remedy in the Eastern region. However, a study focusing on identifying the health benefit of sea cucumbers from tropical waters is still limited. A study on the free radical scavenging activity of five selected sea cucumbers collected from Lampung waters, Indonesia has been done. The objective of this study was to evaluate the free radical scavenging activity of five selected sea cucumbers, namely Stichopus vastus, Stichopus quadrifasciatus, Holothuria (Metriatyla) lessoni, Holothuria (Mertensiothuria) leucospilota, and Bohadschia marmorata. The extraction method which used in this study was the maceration method using methanol solvent while the free radical scavenging activity test is carried out using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) method. Compared to other species at a concentration of 250 µg/mL, S. vastus, S. quadrifasciatus, H. lessoni and H. leucospilota showed the strongest scavenging activity. While B. marmorata was classified as a very weak scavenging activity. It can be concluded that S. vastus, S. quadrifasciatus, H. lessoni H. leucospilota, and H. lessoni are important sea cucumbers from tropical waters as a source of natural antioxidant agents in the future.

Free Radical Scavenging Activity of Infusions of Different Medicinal Plants for Use in Obstetrics

An X-band (9.3 GHz) electron paramagnetic resonance (EPR) spectroscopy was used to examine the free radical scavenging activity of the following infusions, which were nonirradiated and exposed to UVA: root of Asparagus racemosus and herbs of Mitchella repens, Cnicus benedictus L., Galega officinalis L., and Eupatorium cannabinum L. The plant materials for obstetrics applications were chosen for analysis. The aims of these studies were to compare the free radical scavenging ability of the tested infusions and to determine the influence of UVA irradiation of the plant materials on interactions of these infusions with free radicals. Both the magnitude and kinetics of the interactions of the infusions with the model DPPH free radicals were examined. The ability to quench the free radicals for the examined plant infusions increases in the following order: Asparagus racemosus (root) < Mitchella repens (herb) < Cnicus benedictus L. (herb) < Galega officinalis L. (herb) < Eupatorium cannabinum L. (herb). The analyzed infusions differ in the kinetics of the interactions with free radicals. The fastest interactions with free radicals characterize the infusions of Galega officinalis L. herb and Eupatorium cannabinum L. herb. The infusion of Mitchella repens herb interacts with free radicals in the slowest way. UVA radiation reduces the antioxidant interactions of all tested infusions, especially the infusion of Eupatorium cannabinum L. herb, which should be protected against UVA radiation during storage. The weakest decrease of free radical scavenging activity was observed for the infusion of the root of Asparagus racemosus exposed to UVA radiation. UVA radiation affected the speed of the free radical interactions of the infusions, depending on the type of plant materials. EPR spectroscopy is useful to examine the free radical scavenging activity of plant infusions, which is helpful to find effective antioxidants for applications in obstetrics and their optimal storage conditions.

Variation in Phytochemical, Antioxidant and Volatile Composition of Pomelo Fruit (Citrus grandis (L.) Osbeck) during Seasonal Growth and Development

Citrus fruits exhibit a high level of different phytoconstituents, of which the changes in the different parts of the fruit during ripening have not been thoroughly studied yet. Thus, in this study, we have investigated how different parts of pomelo fruit (Citrus grandis L.) are modified throughout the development of two consecutive growing seasons. In detail, the main phytochemical compounds, such as total phenolic content, total flavonoid content, antioxidant capacity, DPPH free radical scavenging activity, Ferric reducing antioxidant power (FRAP), and naringin and tannin content, were analyzed. A systematic metabolism of these compounds was found during the development of the fruit, but some pomelo tissues showed a fluctuating trend, suggesting a dependence on the different growing season. Focusing on the tissue distribution of these compounds, the fruit membrane contained the highest level of total phenolic and flavonoid content; fruit flavedo displayed the highest antioxidant capacities and FRAP activities, whereas maximum accumulation of naringin was noticed in fruit albedo. Instead, the highest DPPH free radical scavenging activity and tannin contents were found in the pomelo juice. Regarding the distribution of compounds, a possible bias pattern for the accumulation of those compounds has been noticed throughout the fruit development. From the GC-MS analysis, a total of 111 compounds were identified, where 91 compounds were common in both seasons. Overall, these results could be useful for the food processing industry as guidelines for excellent quality foods and for introducing health-beneficial products and components into our daily diets.