scholarly journals Characterization and Biotechnological Potential of Two Native Marine Microalgae Isolated from the Tunisian Coast

2021 ◽  
Vol 11 (11) ◽  
pp. 5295
Author(s):  
Jamila Ben Mohamed ◽  
Jihen Elleuch ◽  
Marwa Drira ◽  
Maria Ángeles Esteban ◽  
Philippe Michaud ◽  
...  

Microalgae are attracting considerable interest worldwide. In the present study, two native microalgae strains isolated from Tunisian cost were identified as Chlamydomonas sp. and Navicula sp. We characterized their pigment and protein contents, as well as their carbohydrate and lipid productivity. The predominant fatty acids were found to be α-linolenic acid (C18:3n-3) and palmitoleic acid (C16:1n-7) for Chlamydomonas sp. and Navicula sp. strains respectively. Microalgae methanol extracts showed important in vitro antibacterial activity against all tested gram negative bacteria. Antioxidant activities of methanol extracts were investigated by determining radical scavenging activity according to DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) methods. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay showed that the newly isolated microalgae were not toxic and have potential application in the fish feeds domain as a supplement in fish meal. Also, the biosorption of cadmium from aqueous solutions by microalgae living cells was evaluated. Large removal capacities were obtained with values ranging from 89.8% to 99.38%. These results are very promising as a starting point for a potential application of these new isolates for in situ bioremediation of heavy metals contaminating aqueous systems.

2020 ◽  
Vol 10 (3) ◽  
pp. 312-321
Author(s):  
Idin Sahidin ◽  
Carla W. Sabandar ◽  
Wahyuni ◽  
Rini Hamsidi ◽  
Sandra Aulia Mardikasari ◽  
...  

Background: Marine sponges provided a great source of natural products with promising biological activity. This study was aimed to investigate the chemical constituents of methanol extracts of selected Indonesian marine sponges (Callyspongia sp., Clathria sp., Melophlus sarasinorum, and Xestospongia sp.), collected from the Saponda Islands, Southeast Sulawesi, Indonesia as well as to evaluate their antimicrobial and antioxidant activities. Methods: LCMS/MS analysis used to identify the compounds. Agar well diffusion and DPPH assays were used to evaluate the antimicrobial and antioxidant activities. Results: Chemical screening reported alkaloids, terpenoids, steroids, and saponins from all investigated sponges. The LC-MS/MS analysis identified various compounds which mainly contained steroids. Antimicrobial activity (against Bacillus subtilis, Escherichia coli, Salmonella enterica, and Candida albicans) was only shown by the Xestospongia sp. extract. Meanwhile, extracts of M. sarasinorum, Xestospongia sp., and Callyspongia sp. exhibited potent radical scavenging activity. Conclusion: The study concluded that the selected sponges could provide various groups of compounds. Methanol extracts of these sponges could be used as sources of antimicrobial and antioxidant agents.


2021 ◽  
Vol 25 (1) ◽  
pp. 75-79
Author(s):  
S.O. Olubodun ◽  
G.E. Eriyamremu ◽  
M.E. Ayevbuomwan ◽  
C.I. Nzoputa

The presence of various bioactive components makes it necessary to analyse plants for their potential to act as a source of useful treatments and cures for many inflammatory, infectious and pathogenic diseases. This study was carried out to determine phytochemicals and in-vitro antioxidant activities of the leaf extracts of Acalypha godseffiana. The leaves of A. godseffiana were collected, dried, pulverized and extracted separately with methanol and water using maceration method. The extract was concentrated in vacuo with rotary evaporator at 40oC. The extracts were subjected to quantitative phytochemical analysis and different anti-oxidant analytical procedures like FRAP, DPPH etc to determine the radical scavenging capabilities. The results of phytochemical analysis estimated the quantities and revealed the presence of alkaloids, flavonoids, tannins, saponins and terpenoids which varied in both extracts. The methanol and aqueous extracts exhibited antioxidant activities with relatively high IC50 (IC50 = 3.67 ìg/ml and 4.42ìg/ml respectively) which accounted for a low free radical-scavenging activity when compared with the reference antioxidant, vitamin C (IC50 = 1.51ìg/ml). The results of the study indicates that A. godseffiana leaf extracts contain secondary metabolites and possesses antioxidant properties.


2021 ◽  
pp. 28-38
Author(s):  
Henry Bulama ◽  
Daniel Dahiru ◽  
Joshua Madu

Background: Cataract is a major cause of visual impairment and blindness around the world. This study evaluated the in vitro antioxidant and anti-cataract activities of Cnidoscolus aconitifolius leaves extract and fractions. Antioxidant activities were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiozoline-6-sulfonic acid) (ABTS), total reducing power, and hydrogen peroxide scavenging assays. Anti-cataract potential was evaluated in vitro using goat lenses divided into eight groups of different treatments and incubated in artificial aqueous humor at 37 °C for 72 hours. Glucose-induced opacity in the lenses was observed and biochemical indices quantified (catalase, Malondialdehyde (MDA) and total protein in the lens homogenate). Results: The crude extract and its fractions possess substantial antioxidant activities. The aqueous fraction exhibited the best DPPH radical scavenging activity (IC50 value 78.599 µg/ml); while the dichloromethane fraction exhibited the highest ABTS radical scavenging activity with IC50 66.68 µg/ml. The anti-cataract evaluation of crude and fractions at 250 μg/ml showed a significant increase (p<0.05) in the total protein and catalase activity compared to the cataract control group. The malonaldehyde level decreased significantly (p<0.05) in all the treated groups.


Antioxidants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 210 ◽  
Author(s):  
Pascual García-Pérez ◽  
Eva Lozano-Milo ◽  
Mariana Landín ◽  
Pedro Pablo Gallego

We combined machine learning and plant in vitro culture methodologies as a novel approach for unraveling the phytochemical potential of unexploited medicinal plants. In order to induce phenolic compound biosynthesis, the in vitro culture of three different species of Bryophyllum under nutritional stress was established. To optimize phenolic extraction, four solvents with different MeOH proportions were used, and total phenolic content (TPC), flavonoid content (FC) and radical-scavenging activity (RSA) were determined. All results were subjected to data modeling with the application of artificial neural networks to provide insight into the significant factors that influence such multifactorial processes. Our findings suggest that aerial parts accumulate a higher proportion of phenolic compounds and flavonoids in comparison to roots. TPC was increased under ammonium concentrations below 15 mM, and their extraction was maximum when using solvents with intermediate methanol proportions (55–85%). The same behavior was reported for RSA, and, conversely, FC was independent of culture media composition, and their extraction was enhanced using solvents with high methanol proportions (>85%). These findings confer a wide perspective about the relationship between abiotic stress and secondary metabolism and could serve as the starting point for the optimization of bioactive compound production at a biotechnological scale.


Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5295
Author(s):  
Xinyu Zhao ◽  
Ruyi Chen ◽  
Yueyue Shi ◽  
Xiaoxi Zhang ◽  
Chongmei Tian ◽  
...  

This study aimed to isolate, prepare and identify the main flavonoids from a standardized Smilax glabra flavonoids extract (SGF) using preparative HPLC, MS, 1H NMR and 13C NMR, determine the contents of these flavonoids using UPLC, then compare their pharmacological activities in vitro. We obtained six flavonoids from SGF: astilbin (18.10%), neoastilbin (11.04%), isoastilbin (5.03%), neoisoastilbin (4.09%), engeletin (2.58%) and (−)-epicatechin (1.77%). The antioxidant activity of six flavonoids were evaluated by determining the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2′-Azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS+) radical scavenging activity and ferric reducing antioxidant power (FRAP). In addition, the anti-inflammatory activity of six flavonoids were evaluated by determining the production of cytokines (IL-1β, IL-6), nitric oxide (NO) using enzyme linked immunosorbent assay and the NF-κB p65 expression using Western blotting in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The results showed that (−)-epicatechin, astilbin, neoastilbin, isoastilbin and neoisoastilbin had strong antioxidant activities, not only in DPPH and ABTS+ radicals scavenging capacities, but in FRAP system. Furthermore, all the six flavonoids could significantly inhibit the secretion of IL-1β, IL-6, NO (p < 0.01) and the protein expression of NF-κB p-p65 (p < 0.01) in LPS-stimulated RAW264.7 cells. This study preliminarily verified the antioxidant and anti-inflammatory activities of six flavonoids in S. glabra.


2019 ◽  
Vol 92 (1) ◽  
pp. 87-94 ◽  
Author(s):  
Cigdem Karaaslan ◽  
Hande Gurer-Orhan ◽  
Sibel Suzen ◽  
Luciano Saso ◽  
Omidreza Firuzi ◽  
...  

Antioxidants are helpful in prevention of several diseases related with oxidative stress including neurodegenerative disorders. In recent studies, carbazoles were given proof of promising antioxidant activities. In this article, 9-ethyl-9H-carbazole hydrazone derivatives were synthesized, characterized and their in vitro antioxidant activity and possible cytotoxic effects were investigated. Furthermore, protective effect of the synthesized derivatives against amyloid β-induced damage in PC12 neuronal cells was examined by using MTT assay. The newly synthesized carbazoles were found to have radical scavenging activity with a varying potency both in cell-free and cell-based in vitro assays. Several compounds, especially such as 3d and 3e, 3m and 3n bearing two halogen groups on the phenyl ring, were found to have cytotoxic activity. However, their cytotoxic activities were not higher than that of melatonin. Several compounds also significantly protected neuronal PC12 cells against amyloid β-induced damage, which can be defined as neuroprotective agents. (4-(2-((9-Ethyl-9H-carbazol-3-yl)methylene)hydrazinyl)benzonitrile) 3r was found as the most active compound with both radical scavenging activity and neuroprotective effects against amyloid β-induced damage. These findings might provide an alternative strategy for developing novel carbazole derivatives for management of neurodegenerative diseases, such as Alzheimer's disease.


Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1236
Author(s):  
Seon-Joo Park ◽  
Anshul Sharma ◽  
Hae-Jeung Lee

Amaranth (Amaranthus spp.) plant commonly refers to the sustainable food crop for the 21st century. The crop has witnessed significant attention in recent years due to its high nutritional value and agronomic advantages. It is a relatively well-balanced cosmopolitan food that is a protector against chronic diseases. Usually, the antioxidant activities of amaranth are held responsible for its defensive behavior. Antioxidant activity of plants, generally, is attributed to their phytochemical compounds. The current interest, however, lies in hydrolysates and bioactive peptides because of their numerous biological functions, including antioxidant effect. While the importance of bioactive peptides has been progressively recognized, an integrated review of recent studies on the antioxidant ability of amaranth species, especially their hydrolysates and peptides has not been generated. Hence, in this review, we summarize studies focused on the antioxidant capacity of amaranth renewal over the period 2015–2020. It starts with a background and overall image of the amaranth-related published reviews. The current research focusing on in vitro, in vivo, and chemical assays-based antioxidant activity of different amaranth species are addressed. Finally, the last segment includes the latest studies concerning free radical scavenging activity and metal chelation capacity of amaranth protein hydrolysates and bioactive peptides.


2011 ◽  
Vol 183-185 ◽  
pp. 104-109
Author(s):  
Ning Zhang ◽  
Zhen Yu Wang ◽  
Hua Zhang ◽  
Jian Ren ◽  
Xiu Mei Hao

This study aims to evaluate the antioxidative activities of water and alkaline solution pH=8, 50% ethanolic (APP1 or SAPP1), 75% ethanolic (APP2 or SAPP2) and 100% ethanolic (APP3 or SAPP3) extracts of A. auricular. The antioxidant activities, including the ABTS, superoxide anion radical-scavenging effect, hydrogen peroxide radical-scavenging effect and chelating ability on ferrous ions were studied in vitro. A comparison of the 50% effective concentration (EC50) values of different antioxidative reactions revealed that SAPP3 was more effective in scavenging ABTS, hydrogen peroxide and chelating ability on ferrous ions.SAPP2 showed a higher superoxide radical-scavenging activity. The alkali-soluble polysaccharides extracts showed higher radical-scavenging effect than water-soluble polysaccharides.


2021 ◽  
Vol 9 (1-2) ◽  
pp. 79-89
Author(s):  
Taslima Akter ◽  
Afra Nawar ◽  
Md Nur Alam ◽  
Md Rafiquzzaman

The study was designed to investigate the antioxidant activities of the methanolic extract of leaves of Begonia roxburghii by five different in vitro methods namely Folin-Ciocalteu, total flavonoid content, phosphomolybdenum, total reducing power determination, and DPPH scavenging activity. Phenol content (Gallic acid equivalent) was found as 180.40±0.03 mg/g of the dry sample by the Folin-Ciocalteu method. Flavonoid assay method revealed the content of flavonoids (Quercetin equivalent) as 60.43±0.27 mg/g of the dry sample. Total antioxidant capacity of the extract was observed 243.43±0.11 mg/g ( ascorbic acid equivalent) by phosphomolybdenum method. Free radical scavenging activity (measured by the DPPH test) of the methanolic extract was found 158.36±0.22 μg/mL whereas ascorbic acid, the standard, showed 19.53±0.04 μg/mL. The methanolic extract of Begonia roxburghii leaves exhibited positive and linear dose dependent reducing power activity and its activity was comparable to the standard ascorbic acid for a given dose. Phytochemical screening of the extract showed positive results for alkaloids, carbohydrates, flavonoids, glycosides, saponins, steroids, and tannins, which demonstrate definite pharmacological actions on human body. The extract showed negative results for the steroids. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 79-89, 2020 (June & December)


Author(s):  
Songul Cetik Yildiz ◽  
Cumali Keskin ◽  
Adnan Ayhanci

The aim of this study was to investigate in-vitro antioxidant properties and in-vivo protective effects of different concentrations of Hypericum triquetrifolium Turra. (HT) seed methanol extracts against acute hepatotoxicity, myelotoxicity and hematotoxicity in rats exposed to overdose of cyclophosphamide (CP). HT seed methanol extracts were tested in view of its in-vitro antioxidant activities as total phenolic contents and DPPH free radical-scavenging activity. To investigate in-vivo protective effects of HT seed methanol extracts on rat tissues; tested animals were divided into nine groups. Three groups only were treated with HT extracts (25, 50 and 100 mg/kg HT) for 6 days. Three groups were pre-treated with the extract of HT (25, 50 and 100 mg/kg HT) for 6 days and on the last day they were injected with single dose of CP (150-mg/kg body weight). Two groups were used as control groups and one group was only treated with CP (150 mg/kg) on the 6th day. The toxic effects of CP and protective effects of HT extracts on the nucleated cells which were produced by bone marrow and serum alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), oxidative stress index (OSI) levels were investigated biochemically. Additionally, liver tissue samples were examined histopathologically. Our results show that HT seed methanol extract has high total phenolic content and antioxidant activity. Over dose CP administration caused hepatotoxicity, myelotoxicity and hematotoxicity on rat. Whereas, 25, 50 and 100 mg/kg HT plus CP administered groups showed significant protective effects on nucleated cells. And 25, 50, 100 mg/kg HT plus CP treated groups showed an important decrease on serum ALT, ALP, LDH and OSI levels when compared with CP treated group. Our results showed that the administration of different HT doses with high doses of CP significantly reduced hepatotoxicity, myelotoxicity and hematoxicity on rats.


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