scholarly journals In vitro antimicrobial and antioxidant activities of bioactive compounds (secondary metabolites) extracted from Streptomyces lydicus A2

Author(s):  
Monthon Lertcanawanichakul ◽  
Kanchanat Pondet ◽  
Jutaporn Kwantep
RSC Advances ◽  
2016 ◽  
Vol 6 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Wei Song ◽  
Jinming Shi ◽  
Denis Baranenko ◽  
Jing Jing ◽  
Weihong Lu

Bioactive compounds extracted from wild Acanthopanax senticosus showed radioprotective effects through in vitro antioxidant activities and suppression of radiation injury in mice.


2021 ◽  
Vol 18 (3) ◽  
pp. 245-259
Author(s):  
Stephen Adakole Ejembi ◽  
Titilayo Omolara Johnson ◽  
Jonathan Dingkwoet Dabak ◽  
Augustina Oduje Akinsanmi ◽  
Jane-Rose Ifuanyachi Oche ◽  
...  

Oxidative stress overwhelms the antioxidant mechanisms of living systems, with active involvement in the pathogenesis of several diseases. Natives of Gangnim in the Plateau State of Nigeria may be unknowingly endowed with some protective advantages against oxidative stress for their habitual consumption of Artemisia annua tea. The antioxidant activities of A. annua extracts were determined using in vitro methods and the inhibitory potentials of twenty-nine (29) bioactive compounds of the plant against oxidative stress target proteins were assessed through molecular docking analysis. These extracts showed significantly high activities in scavenging nitric oxide, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and reducing ferric (Fe3+) to ferrous (Fe2+) iron. Virtually, none of the bioactive compounds binds to the active site of the antioxidant protein targets. Rather, 72.41, 93.10 and 75.86% of these compounds bind with high binding affinity to the activator binding sites of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) respectively. 7,8-dimethylalloxazine (-8.10 kcal/mol) ranked highest as a prospective inhibitor of xanthine oxidase (XOX). The antioxidant activity exhibited by the extracts of the locally cultivated A. annua and the molecular interactions of its bioactive compounds against the protein targets used predict that oxidative stress inhibition could be effectively achieved with these phytochemicals.


2020 ◽  
Vol 4 (4) ◽  
pp. 193-201
Author(s):  
Bei Liu ◽  
Qingqing Xu ◽  
Yujing Sun

Abstract Goji berry tea, a traditional herbal tea, is the main ate mode of goji berry in Asia, yet few studies in comparison with red goji berry tea and black goji berry tea are carried out. This study investigated the effects of water temperature and soak time on the colour, phytochemicals, and the antioxidant capacity [2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), and the ferric-reducing antioxidant power (FRAP)] of two goji berry tea. A comparison of the bioactive compounds and antioxidant activities between black and red goji berry tea was conducted. Results showed that both red and black goji berry tea were rich in phytochemicals, giving high antioxidant ability. The levels of bioactive compounds and the antioxidant activity of the two goji berry tea increased as the increases in soak temperature and time. Black goji berry tea had higher phytochemicals and antioxidant property than those of red goji berry tea. Infused at 100° water for the same time, the levels of total polysaccharides (150 mg/100 ml), total polyphenols (238 mg/ml), and antioxidant capacity (550 μmol/100 ml) of black goji berry tea were 3.5, 2, and 5 times higher, respectively, in comparison with red goji berry tea. The results of this study demonstrate that hot drink of goji berry in China is a good habit and black goji berry tea may be a better choice.


Author(s):  
Taha A. Hussien ◽  
Sayed A. El-toumy ◽  
Hossam M. Hassan ◽  
Mona H. Hetta

<p><strong>Objective:</strong><strong> </strong>To evaluate the <em>in vitro</em> cytotoxicity, antioxidant activities and structure-activity relationship of secondary metabolites isolated from <em>Pulicaria undulata</em>.</p><p><strong>Methods: </strong>The methylene chloride-methanol (1:1) extract of the air-dried aerial parts of <em>Pulicaria undulata</em> was fractionated and separated to obtain the isolated compounds by different chromatographic techniques. Structures of the isolated compounds were determined on the basis of the extensive spectroscopic analysis, including 1D and 2D NMR and compared with the literature data. The crude extract and the isolated compounds were evaluated for <em>in vitro</em> antioxidant activity using the 2,2 diphenyl dipicryl hydrazine (DPPH) method and cytotoxic assay using human breast cancer (MCF-7) and hepatoma (Hep G2) cell line.</p><p><strong>Results: </strong>Nine secondary metabolites were isolated from <em>Pulicaria undulata</em> in this study. Of which two terpenoidal compounds; 8-epi-ivalbin and 11β, 13-dihydro-4H-xanthalongin 4-<em>O</em>-β-D-glucopyranoside firstly isolated from the genus <em>pulicaria</em> and three flavonoids; eupatolitin, 6-methoxykaempferol, and patulitrin firstly isolated from <em>P. undulata</em>. 6-methoxykaempferol (IC<sub>50</sub> 2.3 µg/ml) showed the most potent antioxidant activity. The highest cytotoxic effect against MCF-7 and Hep G2 cells was obtained with eupatolitin (IC<sub>50</sub> 27.6 and 23.5 µg/ml) respectively. The structure-activity relationship was also examined and the findings presented here showed that 3, 5, 7, 4' and 3, 5, 4', 5'-hydroxy flavonoids were potent antioxidant and has cytotoxic activity.</p><p><strong>Conclusion: </strong><em>Pulicaria undulata</em> is a promising medicinal plant, and our study tends to support the therapeutic value of this plant as antioxidant drug and in the treatment of cancer.</p>


Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 713 ◽  
Author(s):  
Gokhan Zengin ◽  
Kouadio Ibrahime Sinan ◽  
Mohamad Fawzi Mahomoodally ◽  
Simone Angeloni ◽  
Ahmed M. Mustafa ◽  
...  

In a world where an eco-friendlier approach is becoming more and more necessary, it is essential to reduce waste production and to reuse residues of the company’s supply chain. Coffee silverskin (CS) and spent coffee ground (SCG), two by-products of coffee production, are important sources of bioactive compounds and, for this, some authors have proposed their reuse in the nutraceutical, food, and cosmetic sector. However, their potential enzyme inhibitory properties have been poorly investigated. Hence, the objective of the current work was to study the enzymatic inhibitory activities against acetylcholinesterase, butyrylcholinesterase, α-amylase, α-glucosidase, and tyrosinase of different extracts of CS and SCG. Before these in vitro bioassays, the phytochemical composition of each extract was investigated via colorimetric assays and HPLC-MS/MS analysis. In addition, the antioxidant activities were evaluated by different chemical approaches. SCG extracts contained a higher content of bioactive compounds, notably the SCG EtOH:H2O extract was the richest in caffeine and possessed the highest antioxidant activities. The hydroalcoholic and methanolic extracts were shown to be the most active against all tested enzymes, while the water extracts displayed lower activity. Our results showed a weak correlation between bioactive compounds and enzyme inhibitory effects, proving inhibitory activities likely due to non-phenolic molecules such as alkaloids and terpenoids. Obtained findings could be a starting point to develop novel nutraceuticals from CS and SCG.


Antioxidants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 282 ◽  
Author(s):  
Kishor Mazumder ◽  
Afia Nabila ◽  
Asma Aktar ◽  
Asgar Farahnaky

The aim of this present investigation was to analyze bioactive compounds, as well as demonstrate the antioxidant activities of nine cultivars of Australian lupin species accompanied by observing the effect of domestic heat processing on their antioxidant activities adopting in vivo and in vitro approaches. Gas chromatography mass spectroscopy (GC-MS) analysis was performed for profiling bioactive compounds present in lupin cultivars. Multiple assay techniques involving quantification of polyphenolics, flavonoids and flavonol, electron transfer (ET) based assay, hydrogen atom transfer (HAT)-based assay and in vivo assays were performed. The major compounds found were hexadecanoic acid methyl ester, 9,12-octadecadienoic acid methyl ester, methyl stearate, lupanine,13-docosenamide and 11-octadecenoic acid (Z)- methyl ester. Mandelup was found to show excellent antioxidant activity. Moreover, Jurien, Gunyidi and Barlock had strong antioxidant activity. Both positive and negative impacts of heat processing were observed on antioxidant activity. Heating and usage of excess water during processing were the key determinants of loss of antioxidants. Negligible loss of antioxidant activity was observed in most of the assays whereas inhibition of both lipid peroxidation (33.53%) and hemolysis of erythrocytes (37.75%) were increased after processing. In addition, in vitro and in vivo antioxidant assays are found to show statistically significant (* p < 0.05 and ** p < 0.01) results, which are supported by the presence of a number of antioxidant compounds in GC-MS analysis.


Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 811
Author(s):  
Melanie Platzer ◽  
Sandra Kiese ◽  
Thomas Herfellner ◽  
Ute Schweiggert-Weisz ◽  
Peter Eisner

Plants produce a diverse array of secondary metabolites that are generally nonessential but facilitate ecological interactions. Fruits, vegetables, seeds and nuts can accumulate bioactive secondary metabolites with health-promoting properties, including the potent antioxidant activities of phenolic compounds. Several in vitro assays have been developed to measure the polyphenol content and antioxidant activity of plant extracts, e.g., the simple and highly popular Folin-Ciocalteu (FC) assay. However, the literature contains a number of different descriptions of the assay and it is unclear whether the assay measures the polyphenol content or reducing capacity of the sample. To determine the influence of phenolic structures on the outcome of the FC assay, we tested phenols representing different subgroups (phenolic acids, flavonols, flavanols, dihydrochalcones and flavanones). We observed different results for each reference substance and subgroup. Accordingly, we concluded that the FC assay does not measure the polyphenol content of a sample but determines its reducing capacity instead. Assigning the substances to five structural classes showed that the FC results depend on the number of fulfilled Bors criteria. If a molecule fulfills none of the Bors criteria, the FC results depend on the number of OH groups. We did not find a correlation with other single electron transfer assays (e.g., ABTS and DPPH assays). Furthermore, the FC assay was compatible with all five subgroups and should be preferred over the DPPH assay, which is specific for extracts rich in dihydrochalcones or flavanones.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Syed Mubashar Sabir ◽  
Syed Rizwan Abbas ◽  
Shabnam Shahida ◽  
Muhammad Faraz Khan

Abstract Objective To evaluate the antioxidant activities and to identify the bioactive compounds in hot water extracts of Terminalia chebula fruit. Methods The antioxidant activities were determined by DPPH assay, lipid peroxidation assay, iron chelation and total antioxidant assay. The phenolic composition was determined by HPLC-DAD. Human Rab8b Protein was used for the validation of compounds as anti-inflammation. String analysis for protein synergism was used. Results The analysis of Terminalia chebula Retzius (Combretaceae) phenolics showed anti-inflammatory effect. The specific phenolic compositions were determined by high performance liquid chromatography (HPLC) and resulted in the identification of rutin, catechin, caffeic acid, gallicacid, ellagic acid, epicatechin, and quercetin as antioxidant compounds. Human Rab8b protein is selected for protein docking and all compounds except rutin showed good results. ADMET properties were checked by using AdmetSar and all seven compounds showed validation for AMET properties. The synergisms of compounds were analyzed by STRING analysis and our ligands shows strong binding with human Rab8b proteins. The aqueous extract was capable of inhibiting the lipid peroxidation in egg yolk phospholipid homogenate. The extract scavenged the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) (IC50,71.5 ± 2.1 μg/ml). The extract displayed the high metal chelation activities and reducing abilities on the phosphomolybdenum assay. Conclusions It is concluded that extracts of T. chebula have good antioxidant and anti-inflammation activities and are rich in phenolics.


Author(s):  
Kasthuri O R ◽  
Ramesh B

Objectives: The present study was carried out to determine the phytochemical constituents and in vitro antioxidant activities of leaf extracts of Alternanthera brasiliana (L). Kuntze (A. brasiliana) and Alternanthera bettzickiana regel (A. bettzickiana).Methods: Preliminary phytochemical screening was performed in petroleum ether, chloroform, acetone, ethanol, hydroethanolic and water extracts of leaves of A. brasiliana and A. bettzickiana. The level of alkaloids, flavonoids, total phenolic content, tannins, Vitamin C, Vitamin E, GSH, and total proteins were determined in hydroethanolic, ethanol, and water extracts. Antioxidant activity of the hydroethanolic leaf extracts of A. brasiliana and A. bettzickiana were determined by 2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical scavenging assay, nitric oxide scavenging assay, superoxide anion scavenging assay, ferric reducing antioxidant power assay, total antioxidant capacity, and reducing power assay.Results: The phytochemical screening of six different extracts of A. brasiliana and A. bettzickiana revealed the presence of various phytonutrients. Quantitative analysis of secondary metabolites in ethanol, hydroethanolic and water extracts of leaves of A. brasiliana and A. bettzickiana showed the presence of high amount of secondary metabolites in the hydroethanolic extract. In vitro, antioxidant assay of two plant extracts revealed that A. bettzickiana was more potent than A. brasiliana in scavenging free radicals.Conclusion: The different extracts from A. brasiliana and A. bettzickiana and specifically the hydroethanolic extract of A. bettzickiana revealed several properties such as rich source of phytonutrients, higher free radical scavenging properties, and significant antioxidant capabilities. Therefore, the bioactive compound should be isolated in future studies and could be used as a safe and serve as a potential source of natural antioxidants.


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