Practical mediated-assembly synthesis of silver nanowires using commercial Camellia sinensis extracts and their antibacterial properties

2018 ◽  
Vol 42 (3) ◽  
pp. 2133-2139 ◽  
Author(s):  
M. Flores-González ◽  
M. Talavera-Rojas ◽  
E. Soriano-Vargas ◽  
V. Rodríguez-González

Camellia sinensis is a well-known plant used for health purposes due to its high phenolic compound content and antioxidant properties.

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4593
Author(s):  
Deepthi Venkatachalapathy ◽  
Chandan Shivamallu ◽  
Shashanka Prasad ◽  
Gopenath Thangaraj Saradha ◽  
Parthiban Rudrapathy ◽  
...  

The edible parts of the plants Camellia sinensis, Vitis vinifera and Withania somnifera were extensively used in ancient practices such as Ayurveda, owing to their potent biomedical significance. They are very rich in secondary metabolites such as polyphenols, which are very good antioxidants and exhibit anti-carcinogenic properties. This study aims to evaluate the anti-cancerous properties of these plant crude extracts on human liver cancer HepG2 cells. The leaves of Camellia sinensis, Withania somnifera and the seeds of Vitis vinifera were collected and methanolic extracts were prepared. Then, these extracts were subjected to DPPH, α- amylase assays to determine the antioxidant properties. A MTT assay was performed to investigate the viability of the extracts of HepG2 cells, and the mode of cell death was detected by Ao/EtBr staining and flow cytometry with PI Annexin- V FITC dual staining. Then, the protein expression of BAX and BCl2 was studied using fluorescent dye to determine the regulation of the BAX and BCl2 genes. We observed that all the three extracts showed the presence of bioactive compounds such as polyphenols or phytochemicals. The W. somnifera bioactive compounds were found to have the highest anti-proliferative activity on human liver cancer cells.


Molecules ◽  
2013 ◽  
Vol 18 (10) ◽  
pp. 12548-12560 ◽  
Author(s):  
Lan-Sook Lee ◽  
Chang-Won Cho ◽  
Hee-Do Hong ◽  
Young-Chul Lee ◽  
Ung-Kyu Choi ◽  
...  

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 839
Author(s):  
Karina Jasińska ◽  
Bartłomiej Zieniuk ◽  
Dorota Nowak ◽  
Agata Fabiszewska

The study aimed to evaluate the impact of selected factors of the freeze-drying process on the hydrolytic and synthetic activity of the extracellular lipases of Y. lipolytica KKP 379 and to attempt the use of the crude enzyme preparation as a biocatalyst in the synthesis of geranyl 4-hydroxyphenylpropanoate. Antioxidant and antibacterial properties of the geranyl ester derivative were also investigated in order to evaluate their usefulness as a novel food additive. The studies confirmed that freeze-drying was an effective method of dehydrating yeast supernatant and allowed for obtaining lyophilizates with low water activity from 0.055 to 0.160. The type and concentration of the additive (2–6% whey protein hydrolyzate, 0.5% and 1% ammonium sulphate) had a significant effect on the hydrolytic activity of enzyme preparations, while the selected variants of drying temperature during the freeze-drying process were not significant (10 °C and 50 °C). Low yield of geranyl 4-hydroxyphenylopropionate was shown when the lyophilized supernatant was used (5.3%), but the yield of ester synthesis increased when the freeze-dried Y. lipolytica yeast biomass was applied (47.9%). The study confirmed the antioxidant properties of the synthesized ester by the DPPH• and CUPRAC methods, as well as higher antibacterial activity against tested bacteria than its precursor with 0.125 mM MIC (minimal inhibitory concentration) against L. monocytogenes.


2021 ◽  
Vol 17 ◽  
Author(s):  
Tamás Hofmann ◽  
Eszter Visi-Rajczi ◽  
Levente Albert

Background: Due to their ecological significance and timber value, Quercus species are especially important in Hungary. Nevertheless, the leaves of these species lack a dedicated utilization field and are considered a waste biomass. Materials and Methods: The present study comprehensively analyses three selected oak species (Q. petraea, Q. pubescens, Q. cerris) native to Hungary to assess their antioxidant capacity (FRAP, ABTS, DPPH) and provide information on their polyphenol pool using state-of-the-art liquid chromatographic/tandem mass spectrometric technique. To the best of our knowledge, no such investigation has yet been conducted for the assigned species. Results: According to the results, the antioxidant capacity of the three species’ leaves are roughly equal. Altogether, 109 compounds have been tentatively identified and described, including phenolic acid derivatives, tannins, flavonoid glycosides, and catechins. Compared to other oak leaf samples and other types of plant tissues, the investigated samples contained a large number (24) of acylated polyphenols. Conclusion: The recent findings on the excellent antioxidant and antibacterial properties of acylated polyphenols suggest that the investigated samples could also be beneficial to human health, requiring further analysis.


2018 ◽  
Vol 19 (12) ◽  
pp. 4078 ◽  
Author(s):  
Dahn Clemens ◽  
Michael Duryee ◽  
Cleofes Sarmiento ◽  
Andrew Chiou ◽  
Jacob McGowan ◽  
...  

Doxycycline (DOX), a derivative of tetracycline, is a broad-spectrum antibiotic that exhibits a number of therapeutic activities in addition to its antibacterial properties. For example, DOX has been used in the management of a number of diseases characterized by chronic inflammation. One potential mechanism by which DOX inhibits the progression of these diseases is by reducing oxidative stress, thereby inhibiting subsequent lipid peroxidation and inflammatory responses. Herein, we tested the hypothesis that DOX directly scavenges reactive oxygen species (ROS) and inhibits the formation of redox-mediated malondialdehyde-acetaldehyde (MAA) protein adducts. Using a cell-free system, we demonstrated that DOX scavenged reactive oxygen species (ROS) produced during the formation of MAA-adducts and inhibits the formation of MAA-protein adducts. To determine whether DOX scavenges specific ROS, we examined the ability of DOX to directly scavenge superoxide and hydrogen peroxide. Using electron paramagnetic resonance (EPR) spectroscopy, we found that DOX directly scavenged superoxide, but not hydrogen peroxide. Additionally, we found that DOX inhibits MAA-induced activation of Nrf2, a redox-sensitive transcription factor. Together, these findings demonstrate the under-recognized direct antioxidant property of DOX that may help to explain its therapeutic potential in the treatment of conditions characterized by chronic inflammation and increased oxidative stress.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Kittipot Sirichaiwetchakoon ◽  
Gordon Matthew Lowe ◽  
Griangsak Eumkeb

Tea is one of the most popular beverages in the world. Camellia sinensis tea (CST) or green tea is widely regarded as a potent antioxidant. In Thailand, Pluchea indica (L.) Less. tea (PIT) has been commercially available as a health-promoting drink. This study focused on free radical scavenging activities of PIT, and its ability to protect isolated human low-density lipoproteins (LDL) from oxidation by chemical agents. A preliminary study to investigate the antioxidant nature of PIT was undertaken. These included common antioxidant assays involving 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS), hypochlorous acid (HOCl), and its potential to scavenge peroxynitrite. In separated experiments, isolated human LDL was challenged with either 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH), copper (Cu2+), or 3-Morpholinosydnonimine hydrochloride (SIN-1) to induce LDL oxidation. PIT exhibited antioxidant activity in all test systems and performed significantly better than CST in both DPPH (P<0.05; IC50PIT=245.85±15.83 and CST=315.41±24.18 μg/ml) and peroxynitrite scavenging assays. PIT at 75 μg/ml almost fully prevented the peroxynitrite over a 5 h period. Moreover, it displayed similar properties to CST during the antioxidation of isolated human LDL using AAPH, Cu2+, SIN-1, and hypochlorous acid scavenging assays. However, it revealed a significantly lower ABTS scavenging activity than CST (P<0.05; IC50PIT=30.47±2.20 and CST=21.59±0.67 μg/ml). The main constituents of the PIT were identified using LC-MS/MS. It contained 4-O-caffeoylquinic acid (4-CQ), 5-O-caffeoylquinic acid (5-CQ), 3,4-O-dicaffeoylquinic acid (3,4-CQ), 3,5-O-dicaffeoylquinic acid (3,5-CQ), and 4,5-O-dicaffeoylquinic acid (4,5-CQ). In conclusion, caffeoyl derivatives in PIT could play an important role in potent antioxidant properties. So, it may be further developed to be antioxidant beverages for preventing atherosclerosis and cardiovascular diseases associated with oxidative stress.


Antioxidants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 123 ◽  
Author(s):  
Jessica Gómez ◽  
Mario J. Simirgiotis ◽  
Sofía Manrique ◽  
Beatriz Lima ◽  
Jorge Bórquez ◽  
...  

This research was designed to investigate the metabolite profiling, phenolics, and flavonoids content as well as the potential antioxidant and antibacterial, properties of orange-yellow resin from Zuccagnia punctata Cav (ZpRe). Metabolite profiling was obtained by a ultrahigh resolution liquid chromatography orbitrap MS analysis (UHPLC-ESI-OT-MS-MS). The antioxidant properties were screened by four methods: 2,2-diphenyl-1-picrylhydrazyl assay (DPPH), trolox equivalent antioxidant activity assay (TEAC), ferric-reducing antioxidant power assay (FRAP), and lipid peroxidation in erythrocytes (LP)). The antibacterial activity was evaluated according to the Clinical and Laboratory Standards Institute (CLSI) rules. The resin displayed a strong DPPH scavenging activity (IC50 = 25.72 µg/mL) and showed a percentage of inhibition of LP close to that of the reference compound catechin (70% at 100 µg ZpRe/mL), while a moderated effect was observed in the FRAP and TEAC assays. The resin showed a content of phenolic and flavonoid compounds of 391 mg GAE/g and 313 mg EQ/g respectively. Fifty phenolics compounds were identified by ultrahigh resolution liquid chromatography orbitrap MS analysis (UHPLC-PDA-OT-MS) analysis. Thirty-one compounds are reported for the first time, updating the knowledge on the chemical profile of this species. The importance of the biomolecules identified support traditional use of this endemic plant. Furthermore, additional pharmacological data is presented that increase the potential interest of this plant for industrial sustainable applications.


2020 ◽  
Vol 8 ◽  
pp. e00455
Author(s):  
Solomon Akinremi Makanjuola ◽  
Victor Ndigwe Enujiugha ◽  
Olufunmilayo Sade Omoba ◽  
David Morakinyo Sanni

2020 ◽  
Vol 10 (7) ◽  
pp. 2290 ◽  
Author(s):  
Paula Borrajo ◽  
Mirian Pateiro ◽  
Mohammed Gagaoua ◽  
Daniel Franco ◽  
Wangang Zhang ◽  
...  

In order to make the by-products generated from the porcine industry more valuable, pig livers were used in this trial to obtain protein hydrolysates. Three proteases (alcalase, bromelain, and papain) were utilized for enzymatic hydrolysis with two different durations, 4 and 8 hours. Ultrafiltration process was used for the recovery of the extracts, employing three different membrane pore sizes (30, 10, and 5 kDa). The porcine livers contained considerable amounts of protein (19.0%), considering they are almost composed of water (74.1%). The antioxidant activity of the obtained hydrolysates was investigated using four antioxidant methods (2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2-2′-Azino-di-[3-ethylbenzthiazoline sulfonate] (ABTS) radical scavenging activity, ferric reducing antioxidant power assay (FRAP), and oxygen radical absorbance capacity assay (ORAC)). Antibacterial properties were also measured against Gram-negative and Gram-positive bacteria. Results indicated that the three studied factors (type of enzyme, membrane pore size, and time) significantly affected the parameters evaluated. Hydrolysates obtained at 8 hours with alcalase had the best antioxidant properties. The 30 kDa alcalase extracts exhibited the highest DPPH (562 µg Trolox/g), FRAP (82.9 µmol Fe2+/100 g), and ORAC (53.2 mg Trolox/g) activities, while for ABTS the 10 kDa alcalase showed the higher values (1068 mg ascorbic acid/100 g). Concerning the antibacterial activity, 30 kDa hydrolysates obtained with bromelain for 4 hours exhibited the highest antimicrobial capacity, providing an inhibition of 91.7%.


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