scholarly journals Free Radical Scavenging Activity and Biochemical characteristics of Ulva rigida (Ulvophyceae) and Arthrospira platensis (Cyanophyceae)

Author(s):  
İlknur Ak ◽  
Gülen Türker

In this study, the antioxidant activities and biochemical characteristics of Ulva rigida (Ulvophyceae) and Arthrospira platensis (Cyanophyceae) were determined. The extracts from two seaweed species were evaluated for their free radical scavenging activity, using the 1,1-diphenyl-2-picrylhydrazyl hydrate (DPPH) method, their total phenolic, flavonoid, and condensed tannin contents, through Folin–Ciocalteu, Quettier-Deleu, and Price methods, respectively. The extracts of two seaweeds showed a low free radical scavenging capacity in comparison with commercial antioxidant BHT (butylated hydroxytoluene), and vitamin C. The extract of U. rigida demonstrated greater antioxidant potential with a low IC50 (3.76±0.02 mg/g Ext.). The total phenolic contents were ranged from 2.21±0.08 (U. rigida) to 8.59±0.62 (A. platensis) mg GAE/g of extract. The highest flavonoid content was found in A. platensis as 22.70±0.65 mg rutin/g of extract. The contents of condensed tannin were measured 3.01±0.11 mg CE/g of extract for A. platensis and 3.76±0.06 mg CE/g of extract for U. rigida. According to results obtained, U. rigida and A. maxima possess antioxidant activity and could be used in for future applications in medicine, functional foods, and agriculture.

Medicines ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 70 ◽  
Author(s):  
Kusum Sai ◽  
Rashmi Thapa ◽  
Hari Prasad Devkota ◽  
Khem Raj Joshi

Background: More than 700 plants are reported to be used for medicinal purposes in Nepal; however, many of them are not studied for their scientific evidences. The aims of the present study were the estimation of the total phenolic and flavonoid contents, and the evaluation of the free radical scavenging and α-amylase inhibitory activities of five selected medicinal plants from western Nepal: Aeschynanthus parviflorus Wall. (Gesneriaceae), Buddleja asiatica Lour. (Loganiaceae), Carica papaya L. (Caricaceae), Drepanostachyum falcatum (Nees) Keng f. (Gramineae) and Spondias pinnata (L. f.) Kurz (Anacardiaceae). Methods: The total phenolic content (TPC) and total flavonoid content (TFC) were measured using Folin-Ciocalteu’s phenol reagent and aluminium chloride methods, respectively. A 1,1–diphenyl–2–picrylhydrazyl (DPPH) free radical scavenging assay was used to evaluate the free radical scavenging activity and an α-amylase inhibitory assay was carried out to determine the in vitro antidiabetic activity. Results: The phytochemical screening of five hydroalcoholic plant extracts revealed the presence of various secondary metabolites, including alkaloids, flavonoids, reducing sugars, saponins, terpenoids and tannins. The amounts of total phenolics and flavonoids were found to be the highest in B. asiatica leaf extract, which also showed the most potent free radical scavenging activity. Extract of C. papaya fruits showed the highest α-amylase inhibitory activity, whereas the extracts of B. asiatica leaves and S. pinnata leaves exhibited moderate activity. Conclusions: Some of the medicinal plants selected in this study showed high TPC and TFC values and potent bioactivities. These results may provide the scientific evidences of the traditional uses of these plants. However, further detailed studies on bioactive compounds isolation and identification and evaluation of in vivo pharmacological activities should be performed in future.


Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1617
Author(s):  
Tina Kostka ◽  
Johanna Josefine Ostberg-Potthoff ◽  
Karlis Briviba ◽  
Seiichi Matsugo ◽  
Peter Winterhalter ◽  
...  

Secondary plant metabolites, e.g., polyphenols, are widely known as health-improving compounds that occur in natural functional foods such as pomegranates. While extracts generated from these fruits inhibit oxidative stress, the allocation of these effects to the different subgroups of substances, e.g., anthocyanins, “copigments” (polyphenols without anthocyanins), or polymeric compounds, is still unknown. Therefore, in the present study, polyphenols from pomegranate juice were extracted and separated into an anthocyanin and copigment fraction using adsorptive membrane chromatography. Phenolic compounds were determined by high performance liquid chromatography with photodiode array (HPLC–PDA) detection and HPLC-PDA electrospray ionization tandem mass spectrometry (HPLC–PDA–ESI–MS/MS), while the free radical scavenging activity of the pomegranate XAD‑7 extract and its fractions was evaluated by the Trolox equivalent antioxidant capacity (TEAC) assay and electron spin resonance (ESR) spectroscopy. Compared to juice, the total phenolic content and free radical scavenging potential was significantly higher in the pomegranate XAD-7 extract and its fractions. In comparison to the anthocyanin and copigment fraction, pomegranate XAD-7 extract showed the highest radical scavenging activity against galvinoxyl and DPPH radicals. Moreover, the enriched XAD-7 extract and its fractions were able to protect human hepatocellular HepG2 cells against oxidative stress induced by hydrogen peroxide. Overall, these results indicated that anthocyanins and copigments act together in reducing oxidative stress.


Author(s):  
ISHFAQ KHAN ◽  
NEHA CHAUHAN ◽  
CHAUHAN PK ◽  
MOHD. AZHAR KHAN

Objectives: The main focus of the present study was to evaluate the antimicrobial efficacy (against oral pathogenic bacteria), free radical scavenging activity, and total phenolic and flavonoids content (TPC and TFC) of methanolic extract (ME) of J. regia obtained from Kashmir region. Methods: The plant part was collected and its ME was prepared. ME was subjected to antibacterial activity against oral bacteria such as Staphylococcus aureus, Streptococcus mutans, and Pseudomonas aeruginosa. The free radical scavenging activity was determined using 2,2-diphenyl- 1-picrylhydrazylhydrate (DPPH) assay. TPC and TFC were also determined using a standard curve equation of gallic acid and quercetin. A standard curve using different concentrations of gallic acid and quercetin was drawn from which the concentration of phenols in the test sample was calculated and expressed in mg/g. Results: The ME of J. regia was found effective against all the strains of microorganisms responsible for oral infection understudy. It was also observed that scavenging of DPPH increased with the increase in concentration for both standard ascorbic and methanolic bark extract of J. regia showing its antioxidant potential. The TPC and TFC of ME was found to be 43.35±0.079 and 17.28±0.125. Conclusions: The results obtained from the study clearly indicate that the walnut bark from Kashmir region can be a good candidate for employment as an antibacterial against oral pathogens. J. regia bark was found to be a good source of healthy compounds such as phenolic and flavonoids, suggesting that its bark could be useful to prevent diseases in which free radicals are present.


Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1941
Author(s):  
Arun Kumar Gupta ◽  
Subhamoy Dhua ◽  
Partha Pratim Sahu ◽  
Giulia Abate ◽  
Poonam Mishra ◽  
...  

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.


2019 ◽  
Vol 70 (1) ◽  
pp. 59-62 ◽  
Author(s):  
Ariadna Petronela Fildan ◽  
Ioan Pet ◽  
Daniela Stoin ◽  
Gabriel Bujanca ◽  
Alexandra Teodora Lukinich-Gruia ◽  
...  

Free radical scavenging activity, total phenolic content and the chemical composition of the essential oil isolated by steam distillation from Artemisia dracunculus L. was investigated. The isolation yield was 0.24% (v/w) based on the fresh plant material (leaves). GC-MS investigation identified 21 components, accounting 99.93% of the total amount. The major components were sabinene (42.38%), isoelemicin (12.91%), methyl eugenol (9.09%), elemicin (7.95%) and beta-ocimene (6.46%). The free radical scavenging activity of the essential oil of Artemisia dracunculus L. was evaluated in vitro by the DPPH assay (IC50 = 0.730 � 0.213 mg/mL), BHA and alpha-tocopherol were used as a positive control. The total phenolic content of the tarragon essential oil was evaluated by the Folin-Ciocalteu method (GAE = 0.451 � 0.001 mg/g sample). In view of these data, we consider that tarragon essential oil could represent a new antioxidants source as a reliable option to reduce the usage of synthetic additives.


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