Green Technology Enabled Graphene Oxide Reduction Using Justichia wynaadensis Extract and Assessment of In Vitro Antioxidant and Antibacterial Activity

2018 ◽  
Vol 24 (8) ◽  
pp. 5726-5730 ◽  
Author(s):  
P Shubha ◽  
K Namratha ◽  
K. C Mithali ◽  
V Divya ◽  
M. S Thakur ◽  
...  

Graphene oxide (GO) was reduced using Justichia wynaadensis aqueous extract. GO was mixed with extract and refluxed at 100 °C for 10 h to obtain reduced GO. PXRD of rGO showed broad peak at 2 = 25° and disappearance of 2 = 9.75° after refluxing which indicates efficient removal of oxygen containing groups. SEM images of rGO showed flaky structures typical of retainment of GO structure with folded curtains like appearance of rGO. UV-vis spectra demonstrated absorption band ~300 nm and shoulder at 400 nm corresponding to π–π* transitions and C ═ O bonds respectively indicating that rGO is red shifted due to decrease in oxygen functional groups. rGO showed potent antibacterial activity against Staphylococcus aureus, upon testing against S. aureus and P. aeruginosa. It showed 67% radical scavenging against DPPH at 500 μg/mL concentration. In conclusion, J. wynaadensis aqueous extract efficiently removed oxygen functionalities from GO surface with significant biological activities.

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2626
Author(s):  
Wael Sobhy Darwish ◽  
Abada El Sayed Khadr ◽  
Maher Abd El Naby Kamel ◽  
Mabrouk A. Abd Eldaim ◽  
Ibrahim El Tantawy El Sayed ◽  
...  

Ceratonia siliqua (Carob) is an evergreen Mediterranean tree, and carob pods are potentially nutritive and have medicinal value. The present study was carried out to estimate the possible biological activities of phytochemical-characterized carob pod aqueous extract (CPAE). The phytochemical contents of CPAE were determined by using colorimetric methods and HPLC. In addition, the free radical scavenging properties and anti-diabetic, anti-hemolytic, and antimicrobial activities were estimated by using standardized in vitro protocols. The phytochemical analysis revealed that CPAE was rich in polyphenols, flavonoids, and alkaloids, where it contained a significant amount of gallic acid, catechin, and protocatechuic acid. Furthermore, CPAE exhibited strong antioxidant activity where it prevented the formation of 2, 2-Diphenyl-1-picryl hydrazyl, hydroxyl, and nitric oxide free radicals. Additionally, it had a potent inhibitory effect against digestive enzymes (amylase, maltase, sucrase, and lactase). Moreover, CPAE exhibited anti-Staph aureus, anti-Escherichia coli, anti-Candida albicans, and anti-herpes simplex type I virus (HSV-I). Finally, CPAE protected the erythrocyte membrane from hypotonic solution-induced hemolysis. Altogether, CPAE could be regarded as an interesting source of biologically active antioxidant, anti-diabetic, and antimicrobial preparation for a potential application in pharmaceutical and food supplement fields.


2018 ◽  
Vol 15 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Parvesh Singh ◽  
Nomandla Ngcoya ◽  
Ramgopal Mopuri ◽  
Nagaraju Kerru ◽  
Neha Manhas ◽  
...  

Background: Diabetes Mellitus (DM) is a complex metabolic disease illustrated by abnormally high levels of plasma glucose or hyperglycaemia. Accordingly, several α-glucosidase inhibitors have been developed for the treatment of diabetes and other degenerative disorders. While, a coumarin ring has the privilege to represent numerous natural and synthetic compounds with a wide spectrum of biological activities e.g. anti-cancer, anti-HIV, anti-viral, anti-malarial, anti-microbial, anti-convulsant, anti-hypertensive properties. Besides this, coumarins have also shown potential to inhibit α-glucosidase leading to a generation of new promising antidiabetic agents. However, the testing of O-substituted coumarins for α-glucosidase inhibition has evaded the attention of medicinal chemists. Methods: For O-alkylation/acetylation reactions, the hydroxyl coumarins (A-B) initially activated by K2CO3 in dry DMF were reacted with variedly substituted haloalkanes at room temperature under nitrogen. The synthesized compounds were tested for their α-glucosidase (from Saccharomyces cerevisiae) inhibitory activity and anti-oxidant activity using DPPH radical scavenging activity. In silico docking simulations were conducted using CDocker module in DS (Accelrys) to explore the binding modes of the representative compounds in the catalytic site of α-glucosidase. Results: All the coumarin analogues (A1, B1, A2-A10, B2-B8) including their precursors (A-B) were evaluated for their in vitro α-glucosidase inhibition using acarbose as a standard inhibitor. All the mono O-alkylated coumarins (except A1) showed significant (p <0.05) α-glucosidase inhibition relative to the hydroxyl coumarin (A) with IC50 values ranging between 11.084±0.117 to 145.24± 29.22 µg/mL. Compound 7-(benzyloxy)-4, 5-dimethyl-2H-chromen-2-one (A9) bearing a benzyl group (Ph-CH2-) at position 7 showed a remarkable (p <0.05) increase in the activity (IC50 = 11.084±0.117 µg/mL), almost four-fold more than acarbose (IC50 = 40.578±5.999 µg/mL). The introduction of –NO2 group dramatically improved the anti-oxidant activity of coumarin, while the O-alkylation/acetylation decreased the activity. Conclusion: The present study describes the synthesis of functionalized coumarins and their evaluation for α-glucosidase inhibition and antioxidant activity under in vitro conditions. Based on IC50 data, the mono O-alkylated coumarins were observed to be stronger inhibitors of α-glucosidase with respect to their bis O-alkylated analogues. Coumarin (A9) bearing O-benzyloxy group displayed the strongest α-glucosidase inhibition, even higher than the standard inhibitor acarbose. The coumarin (A10) bearing –NO2 group showed the highest anti-oxidant activity amongst the synthesized compounds, almost comparable to the ascorbic acid. Finally, in silico docking simulations revealed the role of hydrogen bonding and hydrophobic forces in locking the compounds in catalytic site of α-glucosidase.


2021 ◽  
Vol 22 (6) ◽  
pp. 3253
Author(s):  
Clarisse Roblin ◽  
Steve Chiumento ◽  
Cédric Jacqueline ◽  
Eric Pinloche ◽  
Cendrine Nicoletti ◽  
...  

The world is on the verge of a major antibiotic crisis as the emergence of resistant bacteria is increasing, and very few novel molecules have been discovered since the 1960s. In this context, scientists have been exploring alternatives to conventional antibiotics, such as ribosomally synthesized and post-translationally modified peptides (RiPPs). Interestingly, the highly potent in vitro antibacterial activity and safety of ruminococcin C1, a recently discovered RiPP belonging to the sactipeptide subclass, has been demonstrated. The present results show that ruminococcin C1 is efficient at curing infection and at protecting challenged mice from Clostridium perfringens with a lower dose than the conventional antibiotic vancomycin. Moreover, antimicrobial peptide (AMP) is also effective against this pathogen in the complex microbial community of the gut environment, with a selective impact on a few bacterial genera, while maintaining a global homeostasis of the microbiome. In addition, ruminococcin C1 exhibits other biological activities that could be beneficial for human health, as well as other fields of applications. Overall, this study, by using an in vivo infection approach, confirms the antimicrobial clinical potential and highlights the multiple functional properties of ruminococcin C1, thus extending its therapeutic interest.


2021 ◽  
Author(s):  
Jelena S. Katanić Stanković ◽  
◽  
Nikola Srećković ◽  
Vladimir Mihailović

In this study, silver nanoparticles (AgNPs) have been synthesized using the aqueous extract of the aerial parts of B. purpurocaerulea, collected in Serbia. B. purpurocaerulea silver nanoparticles (Bp– AgNPs) synthesis was confirmed using UV-Vis spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The biological potential of synthesized Bp-AgNPs was evaluated in vitro using ABTS assay for determining free radical scavenging potential and microdilution method for analysis of antimicrobial properties. Bp-AgNPs showed high antioxidant activity similar to Bp-extract, comparable to BHT. The synthesized nanoparticles exerted remarkable antibacterial effects, with minimal inhibitory concentration (MIC) values below 20 µg/mL. In the case of some bacterial strains, the results of Bp– AgNPs were comparable or similar to standard antibiotic erythromycin. The antifungal activity of Bp– AgNPs was moderate for most of the used strains. Nevertheless, several fungi were resistant to the NPs action, while two tested Penicillium species were extremely sensitive on Bp-AgNPs with MIC lower than 40 µg/mL. The antimicrobial properties of Bp-AgNPs can be useful for the development of new NPs-containing products.


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 ◽  
Vol 18 ◽  
Author(s):  
Nayla Javed ◽  
Shakeel Ijaz ◽  
Naveed Akhtar ◽  
Haji Muhammad Shoaib Khan

Background: Arctostaphylos uva-ursi (AUU) being rich in polyphenols and arbutin is known to have promising biological activities and can be a potential candidate as a cosmaceutical. Ethosomes encourage the formation of lamellar-shaped vesicles with improved solubility and entrapment of many drugs including plant extracts. Objective: The objective of this work was to develop an optimized nanostructured ethosomal gel formulation loaded with AUU extract and evaluated for skin rejuvenation and depigmentation. Methods: AUU extract was tested for phenolic and flavonoid content, radical scavenging potential, reducing power activity, and in-vitro SPF (sun protection factor) estimation. AUU loaded 12 formulations were prepared and characterized by SEM (scanning electron microscopy), vesicular size, zeta potential, and entrapment efficiency (%EE). The optimized formulation was subjected to non-invasive in-vivo investigations after incorporating it into the gel system and ensuring its stability and skin permeation. Results: Ethosomal vesicles were spherical in shape and Zeta size, zeta potential, PDI (polydispersity index), % EE and in-vitro skin permeation of optimized formulation (F3) were found to be 114.7nm, -18.9mV, 0.492, 97.51±0.023%, and 79.88±0.013% respectively. AUU loaded ethosomal gel formulation was stable physicochemically and exhibited non-Newtonian behavior rheologically. Moreover, it significantly reduced skin erythema, melanin as well as sebum level and improved skin hydration and elasticity. Conclusion: A stable AUU based ethosomal gel formulation could be a better vehicle for phytoextracts than conventional formulations for cosmeceutical applications such as for skin rejuvenation and depigmentation etc.


2021 ◽  
Author(s):  
Ashwini Patil

Abstract The present research deals with the development of a novel bioinspired in situ fabrication of reduced graphene oxide (rGO)-silver nanoparticle (AgNPs) nanocomposite (rGO@AgNCs) using microbes namely Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA). The fabricated rGO@AgNCs were characterized using Ultraviolet-visible (UV) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), particle size analysis, polydispersity index (PDI), zeta potential analysis, energy dispersive X-ray analysis (EDAX), Raman spectroscopy, powder X-ray diffraction (PXRD), high-resolution transmission electron microscopy (HR-TEM) analysis, etc. Furthermore, the rGO@AgNCs-PA and rGO@AgNCs-SA interaction with serum protein, pH stability study, and in vitro dissolution of AgNPs were also performed. The research findings of the proposed study demonstrated the simultaneous reduction of graphene oxide (GO) and AgNPs and the formation of rGO@AgNCs in the presence of microbes. The in vitro dissolution studies of rGO@AgNCs composites showed better AgNPs dissolution with controlled release and offered remarkable matrix integrity throughout the dissolution period. The size and stability of rGO@AgNCs-PA and rGO@AgNCs-SA had no significant changes at physiological pH 7.4. A minimal decrease in the zeta potential of rGO@AgNCs was observed, which may be due to the weak interaction of nanocomposites and albumin. The antibacterial application of the synthesized nanocomposite was evaluated against a pathogenic mastitis-forming bacterium. The obtained results suggested an admirable antibacterial activity of synthesized nanocomposites against the tested microbes. This knowledge will assist the scientific fraternity in designing novel antibacterial agents with enhanced antibacterial activity against various veterinary pathogens in near future.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Kenza Ammor ◽  
Dalila Bousta ◽  
Sanae Jennan ◽  
Bahia Bennani ◽  
Abdellah Chaqroune ◽  
...  

The aim of this study is to investigate in vitro antioxidant and antibacterial activities of the aqueous and hydroethanolic extracts for aerial parts of Herniaria hirsuta. Extracts were screened for their possible antioxidant activities by three tests: DPPH free radical-scavenging, reducing power, and molybdenum systems. The screening of antibacterial activity of extracts was individually evaluated against sixteen bacteria species using a disc diffusion method. Flavonoids, total phenols, and tannins content were performed for both extracts. It shows higher content in the hydroethanolic extract. The hydroethanolic extract showed a significant antioxidant activity for the three methods studies to the aqueous extract, but nonsignificant results compared to the reference (BHT). However, both extracts have negative effect on the strains studies for the antibacterial activity.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Vishmi Sachindra Thrikawala ◽  
Srianthie A. Deraniyagala ◽  
Chamira Dilanka Fernando ◽  
Dinusha Nishani Udukala

There is much interest in plant-based medicine with antidiabetic and antiglycation properties. Chronic hyperglycemia plays a vital role in the development of long-term diabetic complications by inducing protein glycation and the gradual formation of advanced glycation end products (AGEs) in various body tissues. The main objectives of this study were to investigate the aqueous extract of the whole plant of Flueggea leucopyrus Willd (FLAE), a medicinal plant used in traditional medicine in Sri Lanka for its in vitro α-amylase inhibitory activity and its inhibitory potential on the formation of AGEs. α-Amylase inhibitory activity determined by 3,5-dinitrosalicylic acid method revealed that FLAE possesses 29%–91% inhibitory activity at a concentration range of 2.5–400 μg/mL, respectively. Nonenzymatic protein glycation inhibitory capacity assessed by bovine serum albumin-fructose fluorescence spectrometric assay showed that FLAE at 15.6–250.0 μg/mL inhibited AGE formation by 0.9%–98%, respectively. Radical scavenging ability of FLAE using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and total phenolic and flavonoid contents of FLAE were also determined. This study shows that Flueggea leucopyrus Willd not only inhibits α-amylase enzyme, which is known to break starch to glucose, but also inhibits the formation of AGEs, which occur due to chronic hyperglycemia that leads to the onset of diabetic complications.


2021 ◽  
Author(s):  
Hina Gul ◽  
Muhammad Awais ◽  
Salina Saddick ◽  
Falak Sher Khan ◽  
Muhammad Gulfraz ◽  
...  

Abstract Dodonaea viscosa L. Jacq. is an evergreen shrub and native to Asia, Africa and Australia. It has been used as traditional medicine in different countries. The foremost objective of the current study was to discover protective potential of D. Viscosa flowers Methanol (DVM) and Chloroform (DVC) extracts against CCL4 induced toxicity in mice. This study was intended to identify phytochemicals through HPLC, GCMS and FT-IR as well as in vitro antioxidant and in vitro antituberculosis activity. Our comprehensive findings indicate that Dodonaea viscosa is valuable and widespread herbal medicines through therapeutic potentials for curing various ailments. Dodonaea viscosa flowers are found to have protective effect against oxidative stress produced by CCL4 in liver, kidney and spleen. The level of hepatic enzymes (ALP, AST ALT and Direct bilirubin), hematological parameters (RBCs, WBCs and Platelets), total protein and liver antioxidant enzymes (SOD, GPx and CAT) were restored by the intake of DV extracts after decline in levels by CCL4. Histopathological results discovered the defensive effect of 300mg/kg of DVM extract against CCL4 induced damage, thus having improved protective effect as compared to DVC and control. As a result of analysis total flavonoids and total phenolics were also revealed. Phytochemical investigation by HPLC identified gallic acid, epicatechin, cumeric acid, flavonoids while Oleic acid (Octadecenoic acid) (C18H34O2), Stearic acid (C18H36O2), Ricinoleic acid (C18H34O3) and Cedrol (C15H26O) was estimated by GCMS. DVM extract exhibited resistance against in vitro Mycobacterium tuberculosis strains. This study proposed that protective effect of DV against oxidative damage induced in Liver, Kidney and Spleen can possibly be correlated to their antioxidant as well as free radical scavenging property.


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