DPPH radical scavenging method

Free radical scavenging potential of methanolic root extract along with the standard vitamin c at different concentration was tested by the DPPH method are shown in Figure 1. The percentage inhibition of methanolic root extract and ascorbic acid (62.5-500µg/ml) are about 16, 29, 55, 93% and 21, 30, 68 and 95% respectively and it was obvious from the results that values of the standard antioxidant were equal with our methanolic root extract. In support our work results, a similar

This study was subjected to investigate in vitro antibacterial, anti-inflammatory and antioxidant activities of methanol extracts of Eichhornia crassipes. In antibacterial activity the methanolic extract exhibited the best antibacterial activity against Staphylococcus aureus, Bacillus subtilis and Escherichia coli, shows the positive result. Out of these three organisms E.coli shows the high zone of inhibition. Inhibition of albumin denaturation technique was used to determine in-vitro anti-inflammatory activity. DPPH free radical scavenging method and hydrogen peroxide scavenging method were used for antioxidant activity. Antibacterial activity was determined by disc diffusion method. In in-vitro anti-inflammatory investigation there is a linear relation of %inhibition for the Eichhornia crassipes which indicates having positive anti-inflammatory property. In DPPH free radical was calculated by using log dose inhibition curve. Lower absorbance of the reaction mixture indicated higher free radical activity and compared with standard ascorbic acid. Eichhornia crassipes may pocesss potent antibacterial activity, anti-inflammatory, as well as good antioxidant. Keywords: DPPH, Anti-inflammatory, Ascorbic acid, Eichhornia crassipes, Escherichia coli, methanolic extract.

Progression of a large number of common chronic dis- eases is induced by free radical-mediated oxidative dam- age and a lot of health benefits are attributed to the utilization of fruits and vegetables in our diet due to their strong antioxidant capacities. A wide variety of bio- logically active phytochemicals such as polyphenols, flavo- noids, alkaloids, terpenoids, carotenoids etc. are derived from plant foods and natural products which have promis- ing health benefits. These diverse phytocompounds have protective effects against chronic diseases while acting in combination rather than individually [47]. In recent times, the antioxidant content has become an essential biochem- ical marker of plant product quality. The antioxidant cap- acity resulting from hydrophilic or lipophilic compounds individually has been estimated in plant foods. In the present work, we have performed the widely used and well recognized antioxidant capacity assays that have positive influence and applications in biological antioxidant re- search. The DPPH radical scavenging assay is a simple and precise method to measure the antioxidant capacity of plant extracts where the DPPH radical is used as a stable free radical to determine the antioxidant capacity of natural compounds. In our study, the DPPH radical scav- enging capacity of the phytococktail extracts was found to increase in a dose dependent manner. The phytococktail extracts at the used concentrations displayed potential free radicals scavenging effect (Table 1). A higher DPPH rad- ical scavenging capacity is associated with a lower RSa 50

a very good amount of flavonoids and flavonols also showed strong radical scavenging activity in both ABTS and DPPH method. The radical scavenging activities of the selected plants extracts are still less effective than the commercial available synthetic like BHT and trolox. As the plant extracts are quite safe and the use of synthetic antioxidant has been limited because of their toxicity, therefore, these wild edible plants could be exploited as antioxidant additives and supplements for the diseases associated with oxidative stress.

Free radicals are implicated for many diseases including diabetes mellitus, arthritis, cancer, ageing etc. In the treatment of these diseases, antioxidant therapy has gained utmost importance. Ethanolic extract of Alternanthera sessilis (EEAS) was studied for its in vitro antioxidant activity using different models viz. Free radical scavenging activity assay (DPPH method), Reducing power assay, Nitric oxide scavenging activity, Superoxide radical scavenging activity and Hydroxyl radical scavenging activity. Total phenolic content was determined by using Pyrocatechol as a standard. The results were analyzed statistically by the regression method. Its antioxidant activity was estimated by IC 50 value and the values are 74.05 ± 1.44 μg/ml (Superoxide radical scavenging), 31.50 ± 1.04

The bioactive fraction (aqueous fraction) was tested for the anti-oxidant activity. Different in vitro methods such as DPPH free radical scavenging assay, nitric oxide radical scavenging assay, superoxide radical scavenging assay, hydroxyl radical scavenging assay and inhibition of peroxide formation method, was carried out. The percentage inhibition of free radicals produced was found by spectrophotometric method and the values are represented as mean±SD. The absorbance obtained for test and control are noted and the percentage inhibition of radical scavenging activity was calculated using the equation,

A Schiff base ligand 2-[(1E)-N-{2-[(2-{(Z)-[1-(2-hydroxyphenyl) ethylidene] amino}ethyl)amino]ethyl} ethanimidoyl]phenol L was hydrolyzed by copper cation which lead to formation of 8,8-dichloro-2H,3H,5H,6H-1,3-diaza-2-cupracyclopenta[1,3-a]1,3-diaza-2-cupracyclopentane hydrate (Complex), characterized by UV, IR, Powder XRD and by elemental analysis. In vitro antioxidant and anticoagulant, activities of L were evaluated. Antioxidant potential of L was assessed by DPPH scavenging, β-carotene bleaching test, hydroxyl radical scavenging method, ABTS radical scavenging test, and by reducing power test. In vitro anticoagulant effect of L at the 84 µg/mL; showed the maximum prolongation of plasma recalcification time which is comparable with that of the anticoagulant drug; heparin. In conclusion, results of the present investigation indicate that the ligand L can be a potential anticoagulant agent.

Decalepsis hamiltonii (Family: Asclepiadaceae) is a monogeneric climbing scrub native of the Deccan peninsula and forest areas of Western Ghats of India. This is an endemic and endangered medicinal plant largely found in southern parts of India. In this present study the bioactive compounds from Decalepsis hamiltonii was extracted using different solvents –hexane, chloroform, ethyl acetate, ethanol and water. The extracts were then examined for antioxidant activity by ABTS methd, DPPH method, superoxide radical scavenging method, hydrogen peroxide scavenging method and hydroxyl scavenging method. The extract was also screened for in vitro cytotoxicity by means of MTT assay against HeLA, A549, MCF-7, NHDF cell lines. The results obtained reveal that various extracts of D.hamiltonii have significant antioxidant activity and cytotoxic effect.

Chemicals: DPPH (1,1-diphenyl, 2- picrylhydrazyl), NBT (nitro blue tetrazolium), NADH (nicotinamide adenine dinucleotide Abstract: In this study, measure antioxidant potential of P. amarus by DPPH radical scavenging activity, Superoxide radical scavenging activity and Hydroxyl radical scavenging activity method using ether, aqueous and ethanol extract in different propagation also reference compound as Ascorbic Acid. In DPPH radical scavenging activity, ethanol extract show higher percentage inhibition 93.50% at 250µ g/mL. Higher percentage inhibition of all three activities i.e. DPPH, SOD and hydroxyl at 250 µ g/mL by ethanol extract is 96.50 % with reference compound i.e. Ascorbic Acid-97.00%.

The antioxidant activity of methanol extract was determined on the basis of their hydrogen donating or radical scavenging activity of the stable DPPH • according to the method of Blois (1958) [16]. About 0.2mM solution of DPPH • was prepared from this 100µl and was added to various concentration of extracts i.e. 50µg-250µg/ml and shaken vigorously. Absorbance at 517nm was determined after 30 minutes at room temperature and the scavenging activity was calculated as a percentage of the radical reduction. BHT was used as a reference compound. The graph was plotted with mean values. Radical scavenging activity was expressed as the inhibition percentage of free radical by the sample and was calculated using the formula,

The DPPH assay method is based on the reduction of DPPH a stable free radical. The free radical DPPH with an odd electron gives a maximum absorption at 517 nm (purple color). The antioxidant activity of different aegle marmelos extracts were measured in term of hydrogen donating or radical scavenging ability using the stable DPPH method. The ability of extracts to scavenge DPPH radical is determined according to the method of Blois. 1ml of 0.1m DPPH solution was mixed with 3ml of extract (10, 100, 500) in methanol. The mixture was shaken vigorously and incubated for 35 minutes in the dark at room temperature. The absorbance was measured at 517 nm methanol and distilled water were used to get the absorbance zero. A blank sample containing the distilled water and DPPH was also prepared. all determinations were performed. The radical scavenging activities of the tasted samples expressed as percentage of inhibition were calculated according to the following equation.

The reducing power of the whole plant extract was quantified according to the method of Oyaizu [14] . DPPH radical scavenging activity was adopted from those previously described with slight modifications [11] . The total antioxidant potential of sample was determined using Ferric Reducing Ability of Plasma (FRAP) by method of Benzie and strain (1996). FRAP assay measures the change in absorbance at 593 nm owing to the formation of a blue coloured Fe 2+ - TPTZ compound from colourless oxidized Fe 3+ form by the action of electron donating antioxidants. The hydroxyl radical scavenging activity was measured according to the method Klein et al [7] .

DPPH radical scavenging assay uses DPPH to check the ability of the antioxidative compounds (algal extract) acting as radical scavengers of proton. Substances possessing antioxidative activity will bring about the change of color from purple chromogen radical to the pale yellow hydrazine (Arguelles et al., 2017; Goh et al., 2010). This method has been used considerably as an initial method for screening of novel antioxidants because of its simplicity, reproducibility, and stability (Chen et al., 2008; Jiménez et al., 2010). Sargassum siliquosum exerted a potent radical scavenging activity against DPPH free radical showing inhibition percentage that is dose dependent (Table 1 and Fig. 1). The activity of the seaweed extract to scavenge DPPH increases when the tested algal extract concentration is also increased. Furthermore, S. siliquosum extract exhibited greater antioxidant activity than the positive control (ascorbic acid) with an IC 50 of 0.19 mg GAE ml −1 and 0.23 mg GAE ml −1 , respectively.

The ethanolic extracts of aerial part of Ocimum canum (OC) were studied for its antioxidant activity and its role to prevent renal ischemia. The in vitro antioxidant models used were DPPH radical scavenging activity, Hydroxyl peroxide radical scavenging method, reducing power assay & FRAP assay. The study was carried out at different concentration (250, 500, 1000, 2000 µg/ml). Further, the antioxidant activity was studied by using in vivo method to prove its potency in preventing ischemia by incorporating renal ischemia/reperfusion model in Wistar albino rats. The animals were divided into four different groups of six rats in each group. Group-1 was served as Control and received oral saline only once daily for 28 days. Group-2 received (oral saline + RI). Group 3 received Ocimum canum ethanolic leaf extract 300mg/kg bwt dose orally for 28 days, Group-4 were pretreated with Ocimum canum ethanolic leaf extract an oral dose of 100mg/kg bwt for 28 days. After the experimental period all rats were sacrificed and antioxidant defense system and oxidative stress in renal tissue was investigated by histopathological study. The significant results were obtained for all in vitro models and in vivo models. A significant increase in levels of Super Oxide Dismutase (SOD), & decrease of Malondialdehyde (MDA) was found in rats of Group-4 when compared with control. The results of present study indicate that the ethanolic leaf extract of Ocimum canum has significant antioxidant activity and can prevent renal ischemia.

The DPPH is a stable free radical and is widely used to assess the radical scavenging activity of antioxidant component. This method is based on the reduction of DPPH in methanol solution in the presence of a hydrogen donating antioxidant due to the formation of the non radical form DPPH-H. [5] The free radical scavenging activity of all the extracts was evaluated by 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) according to the previously reported method. [5] Briefly, an 0.1mM solution of DPPH in methanol was prepared, and 1mL of this solution was added to 3 mL of the solution of all extracts in methanol at different concentration (125, 250, 500 & 1000 μg/mL). The mixtures were shaken vigorously and allowed to stand at room temperature for 30 minutes. Then the absorbance was measured at 517 nm using a UV-VIS spectrophotometer (Genesys 10S UV: Thermo electron corporation). Ascorbic acid was used as the reference. Lower absorbance values of reaction mixture indicate higher free radical scavenging activity. The capability of scavenging the DPPH radical was calculated by using the following formula. % inhibition= {(A 0 –A 1 )/A 0 )*100}

DPPH radical-scavenging activity: The model of scavenging the stable DPPH radical is a widely used method to evaluate the free radical scavenging ability of various samples (14). DPPH is a stable nitrogen-centered free radical the color of which changes from violet to yellow upon reduction by either the process of hydrogen- or electron- donation. Substances which are able to perform this reaction can be considered as antioxidants and therefore radical scavengers (15). It was found that the radical- scavenging activities of all the compounds increased with increasing concentration. All of them show weak antioxidant activity. Based on the IC 50 results, it was also shown that piperidino 2 and its open ring

The free radical scavenging potential of the ethanolic and aqueous extracts of the leaves of Ziziphus mauritiana Lam, was studied for its in vitro scavenging activity by different methods viz. DPPH radical scavenging, ABTS radical scavenging, lipid peroxidation assay, superoxide scavenging activity, nitric oxide scavenging activity, total antioxidant capacity and Non- enzymatic Glycosylation of Hemoglobin assay. The results were analyzed statistically by regression method. The percentage scavenging and IC 50 values were calculated for all models.

ABSTRACT: The Piper betel is an evergreen and perennial creeper belonging to the Piperaceae family, with glossy heart-shaped leaves and white catkin. It is valued both as a mild stimulant and for its medicinal properties. The total phenolic content of methanolic leaves extract was estimated by Folin-Ciocalteu assay method, and was found to be 0.110 mg/CE/g (Catechine Equivalent per gram). However, antioxidant activity of methanolic leaves extract of Piper betel was determined by DPPH free radical scavenging method. The DPPH radical scavenging activity of methanolic extract of Piper betel was found to be highest at 100μl concentration which was 25.2%. Nevertheless, % DPPH scavenging activity of standard ascorbic acid at same concentration was found to be 40%. The % DPPH scavenging activity increases with the increasing concentration. The concentration of Piper betel needed for 50% inhibition (IC50) was found to be 282.31μg/ml whereas 369.19 μg/ml needed for ascorbic acid.

DPPH (2, 2- Diphenyl-1-Picrylhydrazyl) Radical Scavenging Method: Free radical scavenging activity of the petroleum ether, acetone, chloroform, methanolic and aqueous extract of stem and leaves of Ipomoea hederacea were determined using a stable 2, 2- Diphenyl-1-picrylhydrazyl (DPPH). DPPH is a free radical of violet colour. The antioxidants in the sample scavenge the free radical and turn it into yellow colour. The change of colour from violet to yellow is proportional to the radical scavenging activity.

The free radical scavenging activities of the samples were measured using the stable DPPH radical assay method with some modifications. [8] Sample extracts of different concentrations were added to 1ml of 0.1mM methanolic DPPH solution. The mixture were shaken vigorously and allowed to stand for 20 min in the dark at room temperature and the absorbance was monitored at 517 nm. DPPH solution without samples served as the control. Ascorbic acid at a concentration range of 1-5 μg/ml was considered as standard. DPPH radical scavenging activity percentage was calculated for the samples and the standard using following formula;