scholarly journals Impact of Crystalline Structural Differences Between α- and β-Chitosan on Their Nanoparticle Formation Via Ionic Gelation and Superoxide Radical Scavenging Activities

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2010 ◽  
Author(s):  
Yattra Jampafuang ◽  
Anan Tongta ◽  
Yaowapha Waiprib

α- and β-Chitosan nanoparticles were obtained from shrimp shell and squid pen chitosan with different set of deacetylation degree (%DD) and molecular weight (MW) combinations. After nanoparticle formation via ionic gelation with sodium tripolyphosphate (TPP), the % crystallinity index (%CI) of the α- and β-chitosan nanoparticles were reduced to approximately 33% and 43% of the initial %CI of the corresponding α- and β-chitosan raw samples, respectively. Both forms of chitosan and chitosan nanoparticles scavenged superoxide radicals in a dose-dependent manner. The %CI of α- and β-chitosan and chitosan nanoparticles was significantly negatively correlated with superoxide radical scavenging abilities over the range of concentration (0.5, 1, 2 and 3 mg/mL) studied. High %DD, and low MW β-chitosan exhibited the highest superoxide radical scavenging activity (p < 0.05). α- and β-Chitosan nanoparticles prepared from high %DD and low MW chitosan demonstrated the highest abilities to scavenge superoxide radicals at 2.0–3.0 mg/mL (p < 0.05), whereas α-chitosan nanoparticles, with the lowest %CI, and smallest particle size (p < 0.05), prepared from medium %DD, and medium MW chitosan showed the highest abilities to scavenge superoxide radicals at 0.5–1.0 mg/mL (p < 0.05). It could be concluded that α- and β-chitosan nanoparticles had superior superoxide radical scavenging abilities than raw chitosan samples.

2011 ◽  
Vol 63 (3) ◽  
pp. 717-721
Author(s):  
Fan Yang ◽  
Zhiwei Yang ◽  
Jianbo Xiao

A preparation of crude polysaccharides (TPS) was isolated from Camellia sinensis by precipitation and ultrafiltration. TPS1, TPS2, and TPS3 had molecular weights of 240, 21.4, and 2.46 kDa, respectively. The radical scavenging activities of TPS were evaluated by DPPH free radical, hydroxyl radical and superoxide radical scavenging. These results revealed that TPS exhibited strong radical scavenging activity in a concentration-dependent manner. TPS3 with lowest molecular weight showed a higher radical scavenging activity.


Author(s):  
Mentham Ramesh ◽  
Chandu Babu Rao

The current investigation is intended to evaluate the content of phytochemical constituents and antioxidant potential of hydroalcoholic extracts of stem and root of Grewia serrulata DC (HAESGS & HAERGS) and leaf and bark of Grewia Nervosa (Lour.) panigrahi (HAELGN & HAEBGN). Initially, all the extracts at different concentrations were estimated for their total phenolic content and total flavonoid content. The study was further extended for their antioxidant potential evaluation using various in vitro methods such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical and superoxide radical scavenging assays. The total phenolic content (mg gallic acid equivalent per gram of extract) was high in HAELGN (170.82±0.19) and HAERGS (123.00±0.48) than HAESGS (111.2±0.26) and HAEBGN (119.60±0.23). The total flavonoid content (mg quercetin equivalent per gram) is greater in HAERGS (71.24±0.50) and HAESGS (65.68±0.27) than HAELGN (55.82±0.35) and HAEBGN (62.38±0.45). The IC50 values (µg/ml) of different plant extracts inferred that DPPH radical scavenging activity is greater in HAELGN (42.91±0.88) and HAEBGN (53.87±0.35) than HAESGS (126.73±1.20) and HAERGS (88.87±1.25). However, hydroxyl and superoxide radical scavenging activity is more in HAERGS (135.41±1.19 & 88.00±1.42) and HAELGN (172.28±1.91 & 108.163±1.09) than HAESGS (237.3±1.65 & 110.074±0.87) and HAEBGN (204.7±1.04 & 125.54±1.07). The results of present comprehensive analysis demonstrated that both the plants Grewia serrulata DC and Grewia Nervosa (Lour.) panigrahi possess high phenolic, flavonoid contents and potential antioxidant activity, and could be used as a valid source of natural antioxidants and might be utilized for pharmacological screening of various therapeutic activities. Keywords: Grewia serrulata; Grewia Nervosa; Total Phenolic content; Total flavonoid content; Antioxidant potential


2021 ◽  
Vol 17 ◽  
Author(s):  
Brahim Asseli ◽  
Reguia Mahfoudi ◽  
Amar Djeridane ◽  
Mohamed Yousfi

Background: Research on medicinal plant antioxidants has emerged as a potential therapeutic to prevent free radical generated damage in the human body. Hammada elegans Botsch (popularly known as “Ajram”) is a xerophytic plant widely found in Laghouat region, but there are only a few reports about the biological or chemical properties of these species. Hence, the aim of this study is to investigate the antioxidant and the antihemolytic activities of hexanic, acetonic, methanolic and aqueous extracts of aerial parts of Algerian Hammada elegans Botsch by employing different in vitro assay systems. Methods: The total phenolic content, the flavonoid content and the condensed tannin amount were analyzed using Folin-Ciocalteu, aluminum chloride and vanillin assays, respectively. The in vitro antioxidant capacity of extracts was assessed by CUPRAC, iron chelating, ABTS•+and antihemolytic assays, and was expressed as EC50 values. Results: Among the analyzed extracts, the aqueous extract had the highest phenolic, flavonoid and tannin contents. Also, this extract displayed the highest antioxidant capacities compared to the other extracts and standards. Its EC50 value for ABTS radical-scavenging activity was 0.265 ± 0.003 mg/L. Moreover, this extract showed high iron (II) chelating ability (EC50 = 0.958 ± 0.001 mg/L), and good antioxidant activity in the cupric ion reducing activity (CUPRAC) in a concentration dependent manner (EC50 were 0.709 ± 0.002 mg/L). Additionally, this extract had the best antihemolytic activity against AAPH-induced hemolysis (EC50=0.090 ± 0.004 mg/L). Conclusion: Our study revealed that the aqueous extract of Hammada elegans Botsch, is a potential source of antioxidants which possess a high protective effect of membrane against free radical.


2021 ◽  
Author(s):  
Qinjian Li ◽  
Fei Xie ◽  
Yang Yi ◽  
Pengxiang Zhao ◽  
Xin Zhang ◽  
...  

AbstractSince Ohsawa et al. reported a biological antioxidant function of hydrogen in 2007, researchers have now shown it to exert protective effects in a wide range of human and animal disease models. Clinical observations and scientific arguments suggest that a selective scavenging property of H2 cannot adequately explain the beneficial effects of hydrogen. However, there is no experiment challenging the original published data, which suggested that molecular hydrogen dissolved in solution reacts with hydroxyl radicals in cell-free systems. Here we report that a hydrogen-saturated solution (0.6 mM) did not significantly reduce hydroxyl radicals in the Fenton system using 1 mM H2O2. We replicated the same condition as Ohsawa’s study (i.e. 5 μM H2O2), and observed a decrease in •OH radicals in both the H2-rich and N2-rich solutions, which may be caused by a decreased dissolved oxygen concentration. Finally, we determined the effect of hydrogen on a high-valence iron enzyme, horseradish peroxidase (HRP), and found that hydrogen could directly increase HRP activity in a dose-dependent manner. Overall, these results indicate that although H2 and •OH can react, the reaction rate is too low to have physiological function. The target of hydrogen is more complex, and its interaction with enzymes or other macro-molecules deserve more attention and in-depth study.


2021 ◽  
Author(s):  
Noppol Leksawasdi ◽  
Siraphat Taesuwan ◽  
Trakul Prommajak ◽  
Charin Techapun ◽  
Rattanaporn Khonchaisri ◽  
...  

Abstract Green soybean (Glycine max L.) pods (GSP) are agro-industrial waste from the production of frozen green soybean and milk. These pods contain natural antioxidants and various bioactive compounds that are still underutilized. Polyphenols and flavonoids in GSP were extracted by ultrasound techniques and used in antioxidant fortification of green soybean milk. The ultrasound extraction that yielded the highest total polyphenol content was 50% amplitude for 10 min, whereas maximum flavonoids content was obtained at 50% amplitude for 15 min. Radical scavenging activity assayed by 2,2-diphenyl-1-picryl-hydrazyl radical (DPPH) and ferric reducing antioxidant power (FRAP) methods did not differ significantly (p>0.05) between the two conditions. Response surface methodology was applied to analyze an optimum ultrasonic-assisted extraction (UAE) condition of these variables. The highest desirability was found to be 50% amplitude with extraction time of 12.5 min. Fortification of the GSP extracts (1-3% v/v) in green soybean milk resulted in higher levels of bioactive compounds and antioxidant activity in a dose-dependent manner. Procyanidins were found to be the main polyphenols in dried GSP which were present at the concentration of 104.1 ± 2.1 mg/g dry sample, respectively. Addition of GSP extracts obtained by using an ultrasound technique to green soybean milk increased its bioactive compound content especially procyanidins as well as its antioxidant activity.


2008 ◽  
Vol 5 (s2) ◽  
pp. 1123-1132 ◽  
Author(s):  
H. Vijay Kumar ◽  
C. R. Gnanendra ◽  
Nagaraja Naik ◽  
D. Channe Gowda

Dibenz[b,f]azepine and its five derivatives bearing different functional groups were synthesized by known methods. The compounds thus synthesized were evaluated for antioxidant potential through different in vitro models such as (DPPH) free radical scavenging activity,ß-carotene-linoleic acid model system, reducing power assay and phosphomolybdenum method. Under our experimental condition among the synthesized compounds dibenz[b,f]azepine (a) and 10-methoxy-5H-dibenz[b,f]azepine (d) exhibited potent antioxidant activity in concentration dependent manner in all the above four methods. Butylated hydroxyl anisole (BHA) and ascorbic acid (AA) were used as the reference antioxidant compounds. The most active compounds like dibenz[b,f]azepine and its methoxy group substituent have shown more promising antioxidant and radical scavengers compared to the standards like BHA and ascorbic acid. It is conceivable from the studies that the tricyclic amines,i.e. dibenz[b, f]azepine and some of its derivatives are effective in their antioxidant activity properties.


2015 ◽  
Vol 70 (9-10) ◽  
pp. 227-235 ◽  
Author(s):  
Rafal S.A. Al-Anee ◽  
Ghassan M. Sulaiman ◽  
Khulood W. Al-Sammarrae ◽  
Giuliana Napolitano ◽  
Renzo Bagnati ◽  
...  

Abstract Hymenocrater longiflorus was collected from northern Iraq, and the chemical composition and antioxidant and cytotoxic activities of this plant were investigated. Ten compounds detected by HPLC-ESI/MS were identified as flavonoids and phenolic acids. The free radical scavenging activity of the 70% methanol extract was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The antioxidant activities of the extract may be attributed to its polyphenolic composition. The cytotoxicity of the plant extract against the osteosarcoma (U2OS) cell line was assessed with the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The extract significantly reduced the viability of cells in a concentration- and time-dependent manner. Cells were arrested during the S-phase of the cell cycle, and DNA damage was revealed by antibodies against histone H2AX. The apoptotic features of cell shrinkage and decrease in cell size were also observed. Western blot analysis revealed cleavage of poly (ADP-ribose)-polymerase 1 (PARP-1), in addition to increases in the proteins p53, p21, and γ-H2AX. Collectively, our findings demonstrate that the H. longiflorus extract is highly cytotoxic to U2OS cells, most likely due to its polyphenolic composition.


Antioxidants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 177 ◽  
Author(s):  
Guillermo Cásedas ◽  
Francisco Les ◽  
Carmen Choya-Foces ◽  
Martín Hugo ◽  
Víctor López

Urolithin A is a metabolite generated from ellagic acid and ellagitannins by the intestinal microbiota after consumption of fruits such as pomegranates or strawberries. The objective of this study was to determine the cytoprotective capacity of this polyphenol in Neuro-2a cells subjected to oxidative stress, as well as its direct radical scavenging activity and properties as an inhibitor of oxidases. Cells treated with this compound and H2O2 showed a greater response to oxidative stress than cells only treated with H2O2, as mitochondrial activity (MTT assay), redox state (ROS formation, lipid peroxidation), and the activity of antioxidant enzymes (CAT: catalase, SOD: superoxide dismutase, GR: glutathione reductase, GPx: glutathione peroxidase) were significantly ameliorated; additionally, urolithin A enhanced the expression of cytoprotective peroxiredoxins 1 and 3. Urolithin A also acted as a direct radical scavenger, showing values of 13.2 μM Trolox Equivalents for Oxygen Radical Absorbance Capacity (ORAC) and 5.01 µM and 152.66 µM IC50 values for superoxide and 2,2-diphenyss1-picrylhydrazyl (DPPH) radicals, respectively. Finally, inhibition of oxidizing enzymes, such as monoamine oxidase A and tyrosinase, was also detected in a dose-dependent manner. The cytoprotective effects of urolithin A could be attributed to the improvement of the cellular antioxidant battery, but also to its role as a direct radical scavenger and enzyme inhibitor of oxidases.


2014 ◽  
Vol 9 (5) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Rosa Tundis ◽  
Khaled Rashed ◽  
Ataa Said ◽  
Francesco Menichini ◽  
Monica R. Loizzo

The flowers of Bombax ceiba were investigated for their chemical composition, antioxidant effects and antiproliferative activity against seven human cancer cell lines. The antiproliferative responses of diethyl ether (DE) and light petroleum (PE) extracts were evaluated by sulforhodamine B (SRB) assay against MCF-7, HeLa, COR-L23, C32, A375, ACHN, and LNCaP cells in comparison with a human normal cell line, 142BR. Moreover, extracts were characterized by GC-MS analysis and tested for their antioxidant properties by different in vitro systems, namely DPPH, Fe-chelating activity and β-carotene bleaching test. Both PE and DE extracts showed the highest antiproliferative activity against human renal adenocarcinoma (ACHN) in a concentration-dependent manner. PE extract showed the highest radical scavenging activity against the DPPH radical, while DE extract was more active in the β-carotene bleaching test. The presence of β-sitosterol and some fatty acids may contribute to the bioactivity of B. ceiba flower extracts.


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