Mutagenic,antimutagenic and antioxidant potency of leaf extracts from Nitraria retusa

Four extracts were prepared from the leaves of Nitraria retusa; methanol, ethyl acetate, chloroform and hexane extracts. An assay for the ability of these extracts to prevent mutations induced by various oxidants in Salmonella typhimurium TA102 and TA 104 strains was conducted. These extracts from leaf parts of N. retusa showed no mutagenicity either with or without the metabolic enzyme preparation (microsome fraction). The highest protection against methylmethanesulfonate induced mutagenicity was observed with chloroform and methanol extracts with inhibition percentages of 44.93% (at 50 μg/plate in the presence of TA102 strain) and 38% (at 10 μg/plate in the presence of TA104 strain), respectively. Whereas Hexane and chloroform extracts reduced the mutagenicity induced by 2-aminoanthracene by 83.4% (using the S. typhimurium TA104 assay system) and 65.3% (using the S. typhimurium TA 102 assay system), respectively. Antioxidant activity of N. retusa extracts was determined by the ability of each extract to protect plasmid DNA against strand scission induced by hydroxyl radicals. Chloroform extract exhibited the highest ability to protect plasmid DNA against hydroxyl radical induced DNA damages and exhibited the highest antioxidant capacity, with 0.95 mM trolox equivalent when tested by the ferric reducing/antioxidant method.     

Cell protection induced by Acacia salicina extracts: Inhibition of genotoxic damage and determination of its antioxidant capacity

Antioxidant activity of Acacia salicina extracts was determined by the ability of each extract to inhibit lipid peroxidation, to protect against DNA strand scission induced by hydroxyl radicals, and to scavenge the free radical, 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^?+). The IC₅₀ values of the inhibitory activity toward lipid peroxidation of total oligomer flavonoids (TOF), methanol, ethyl acetate, and aqueous extracts were respectively 28, 52, 472, and 480 μg/mL. All extracts have the ability to scavenge the ABTS^?+ radical by a hydrogen-donating mechanism and to protect pKS plasmid DNA against hydroxyl radicals- induced DNA damage. An assay for the ability of A. salicina extracts to prevent mutations induced by various mutagens in Salmonella typhimurium TA102 and TA104 cells was conducted. TOF, methanol, ethyl acetate, and aqueous extracts from leaf parts of A. salicina showed no mutagenicity either with or without the metabolic enzymes preparation (S9). Protection against methylmethanesulfonate-induced mutagenicity was observed for TOF, methanol, and ethyl acetate extracts. Likewise, all extracts exhibited a high inhibition level of the Ames response induced by the indirect mutagen, 2-aminoanthracene. The antigenotoxic activity could be ascribed, at least in part, to their antioxidant properties, but we cannot exclude additionally mechanisms. Thus, A. salicina may serve as an ideal candidate for a cost- effective, readily exploitable natural phytochemical compound.     

Investigation of extracts from (Tunisian) Cyperus rotundus as antimutagens and radical scavengers

This study evaluates mutagenic and antimutagenic effects of aqueous, total oligomers flavonoïds (TOF), ethyl acetate and methanol extracts from aerial parts of Cyperus rotundus with the Salmonella typhimurium assay system.The different extracts showed no mutagenicity when tested with Salmonella typhimurium strains TA98, TA100, TA1535 and TA1538 either with or without the S9 mix. On the other hand, our results showed that all extracts have antimutagenic activity against Aflatoxin B1 (AFB1) in TA100 and TA98 assay system, and against sodium azide in TA100 and TA1535 assay system. TOF, ethyl acetate and methanol extracts exhibited the highest inhibition level of the Ames response induced by the indirect mutagen AFB1. Whereas, ethyl acetate and methanol extracts exhibited the highest level of protection towards the direct mutagen, sodium azide, induced response. In addition to antimutagenic activity, these extracts showed an important free radical scavenging activity towards the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical. TOF, ethyl acetate and methanol extracts showed IC₅₀ value of 15, 14 and 20 μg/ml, respectively.Taken together, our finding showed that C. rotundus exhibits significant antioxidant and antimutagenic activities.     

Antioxidant activities of bark extract from mangroves, Bruguiera cylindrica (L.) Blume and Ceriops decandra Perr

Objectives:

The antioxidant activities of two Indian mangrove plants, Bruguiera cylindrica and Ceriops decandra, were investigated.

Materials and Methods:

Total phenolics and total flavonoid contents of the mangroves were determined using folin-ciocalteu reagent method and aluminium chloride method, respectively. Antioxidant capacity was assessed by the following methods: 1,1-diphenyl-2-picryl hydroxyl (DPPH.) quenching assay; 2,2’- azinobis-3-ethylbenzothiozoline-6-sulfonic acid (ABTS.⁺) cation decolorization test; scavenging capacity towards hydroxyl ion radicals (.OH); reductive capacity; and antihemolytic activity.

Results:

The mangroves yielded 233.3 ± 0.062 and 283.31 ± 0.04 mg gallic acid equivalent/g phenolic contents and 11.6 ± 0.12 and 15.1 ± 0.02 mg quercetin equivalent/g flavonoid contents. The methanol extracts of both mangroves exhibited high antiradical activity against DPPH., ABTS.⁺, and .OH radicals. The reductive capacity of the extracts increased with increasing concentration of samples. The extracts also inhibited H₂O₂ induced hemolysis in cow blood erythrocytes. The antioxidant activities were found stronger than that of the reference standard, butylated hydroxy toluene (BHT). The antioxidant activity of mangrove plants was correlated with total phenolics and flavonoid contents.

Conclusion:

Both plants can be considered as good sources of natural antioxidants for medicinal uses. Further studies are necessary to isolate active principles responsible for the overall antioxidant activity of the extracts.     

Comparative analysis of the antioxidant and DNA protection capacities of Anadenanthera colubrina, Libidibia ferrea and Pityrocarpa moniliformis fruits

This study aimed to explore the antioxidant and DNA protection abilities of hydroalcoholic extracts from fruits of Anadenanthera colubrina (ACHE), Libidibia ferrea (LFHE) and Pityrocarpa moniliformis (PMHE). These extracts were tested by five antioxidant methods (phosphomolibdenium and reducing power assays; superoxide, hydrogen peroxide and nitric oxide scavenging) and DNA protection capacity. Total phenolic content was measured by Folin-Ciocalteu method. ACHE exhibited the highest phenolic content (578 mg/g GAE), followed by LFHE (460 mg/g GAE) and PMHE (448 mg/g GAE). In phosphomolibdenium assay, ACHE showed 24.81% of activity in relation to ascorbic acid, whereas LFHE and PMHE had 21.08% and 18.05%, respectively. These plants showed high ability to inhibit reactive species tested with IC50 values ranged from 10.66 to 14.37 μg/mL for superoxide radical; 26.05 to 45.43 μg/mL for hydrogen peroxide; 178.42 to 182.98 μg/mL for reducing power; and 199.2 to 283 μg/mL for nitric oxide. Furthermore, these extracts had capacity to break the DNA damage induced by hydroxyl radicals. The antioxidant activity of these plants is related with their higher phenolic content and show that they may be used as source of bioactive compounds, relevant to the maintenance of oxidative stability of the food matrix, cosmetics and/or pharmaceutical preparations.     

In vitro Antioxidant and Antibacterial Activities of Methanol Extract of Kyllinga nemoralis

The present study was designed to evaluate the antioxidant and antibacterial activity of methanol extract of Kyllinga nemoralis. Six different in vitro antioxidant assays including 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, superoxide anion radical, hydrogen peroxide radical, ferric reducing antioxidant power assay and reducing power were carried out to ensure the scavenging effect of the plant on free radicals. In addition, total antioxidant capacity assay, total phenolic contents, tannins, flavonoids and flavonol contents of the plant were also analysed by the standard protocols. Kyllinga nemoralis exhibited high antioxidant activity on 2,2-diphenyl-1-picrylhydrazyl assay (IC₅₀= 90 μg/ml), superoxide radical scavenging assay (IC₅₀= 180 μg/ml) and hydrogen peroxide radical scavenging assay (IC₅₀= 200 μg/ml), compared with standards. These observations provide comprehensible supporting evidence for the antioxidant potential of the plant extract. Reducing power (IC₅₀= 213.16 μg/ml) and hydroxyl radical scavenging activity (IC₅₀= 223 μg/ml) of the plant extract was remarkable. The methanol extract of K. nemoralis exhibited significant antimicrobial activity against Gram-positive human pathogenic bacteria. Standard in vitro antioxidant assays assessed the electron donating ability of the plant extract in scavenging free radicals. The inhibitory effect of the plant extract against bacterial pathogens may be due to the presence of phytochemicals. Thus, the results suggest that Kyllinga nemoralis is a potential source of antioxidants and could serve as the base for drug development.     

Comparative study on antioxidant activity of different varieties of commonly consumed legumes in India

Legumes are rich source of proteins, dietary fiber, micronutrients and bioactive phytochemicals. Thirty different varieties of commonly consumed legumes in India, were screened for phenolic content and antioxidant activity using, radical scavenging [(1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenz-thiazoline-6-sulfonic acid, (ABTS⁺)], Ferric Reducing Antioxidant Power (FRAP) and metal ion (Fe²⁺) chelation assays. Legumes varied largely in their antioxidant activity. Horse gram, common beans, cowpea (brown and red) and fenugreek showed high DPPH radical scavenging activity (>400 units/g), while lablab bean (cream and white), chickpea (cream and green), butter bean and pea (white and green) showed low antioxidant activity (<125 units/g). Green gram, black gram, pigeon pea, lentils, cowpea (white) and common bean (maroon) showed intermediate activity. Similar trend was observed when the activity was assessed with ABTS⁺ and FRAP assays. Thus most of the varieties having light color seed coat, except soybean exhibited low antioxidant activity. While legumes having dark color seed coat did not always possessed high antioxidant activity (e.g. moth bean, black pea, black gram, lentils). Antioxidant activity showed positive correlation (r² > 0.95) with phenolic contents, in DPPH, ABTS⁺ and FRAP assays, whereas poor correlation (r² = 0.297) was observed between Fe²⁺ chelating activity of the legumes and phenolic contents.     

Scavenging capacity of strawberry tree (Arbutus unedo L.) leaves on free radicals

Despite strawberry tree (Arbutus unedo L.) leaves had a long use in traditional medicine due to its antiseptic, diuretic, astringent and depurative properties, the potential of their antioxidant activity are still lacking. Our study goals to assess the antioxidant and free radical scavenging potential of water, ethanol, methanol and diethyl ether extracts of A. unedo leaves. Total phenols content was achieved spectrophotometrically using Folin–Ciocalteau reagent with gallic acid as standard. Antioxidant activity was evaluated using three different methods: reducing power of iron (III)/ferricyanide complex assay, scavenging effect on DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and scavenging effect on superoxide radicals by using the PMS–NADH–nitroblue tetrazolium system. Ethanol extracts of A. unedo leaves were the highest in reducing power (IC₅₀ 232.7 μg/mL) and DPPH scavenging effect (IC₅₀ 63.2 μg/mL) followed by water extracts (with IC₅₀ of 287.7 and 73.7 μg/mL, respectively); whereas diethyl ether extracts were the lowest. In the scavenging on superoxide radical assay, methanol extracts obtained the best results (IC₅₀ 6.9 μg/mL). For all the methods tested the antioxidant activity was concentration dependent. In accordance with antioxidant activity, highest total phenols content were found in ethanol, followed by water, methanol and diethyl ether extract. The results indicated that A. unedo leaves are a potential source of natural antioxidants.     

A New Flavonoid C-Glycoside from Celtis australis L. and Celtis occidentalis L. Leaves and Potential Antioxidant and Cytotoxic Activities

A major development over the past two decades has been the realization that free radical induced lipid peroxidation and DNA damage are associated with major health problems, e.g. cancer and ageing. Plant-derived antioxidants are increasingly found beneficial in protecting against these diseases. Celtis australis L. and Celtis occidentalis L. are two plants that have a variety of uses in folk medicine but have not been evaluated before for their antioxidant and cytotoxic properties. Therefore, the extracts of both plants’ leaves were investigated for these activities, as well as isolation of the bioactive compounds responsible for the activities. Molecular structures of the compounds were elucidated by UV, HRESIMS, 1D (¹H and ¹³C) and 2D (¹H-¹³C HSQC and ¹H-¹³C HMBC) NMR analyses. The ethanolic and aqueous extracts, n-butanol fractions and the isolated major compound were tested for their antioxidant activity using DPPH radical scavenging assay, xanthine oxidase-induced generation of superoxide radical and lipid peroxidation assay by thiobarbituric acid-reactive substances (TBARS) method using rat tissue homogenates. Cytotoxic activities were studied using standard MTT assay. A novel flavonoid C-triglycoside, 4‴-α-rhamnopyranosyl-2″-O-β-d-galactopyranosylvitexin, was isolated from both plants’ leaves, together with seven known flavonoids. The n-butanol fractions and the major compound 2″-O-β-galactopyranosylvitexin showed significant antioxidant activities, more pronounced than the tested standards BHT and dl-α-tocopherol in most tests. All extracts showed variable cytotoxic activities. This study provides strong evidence for the antioxidant and cytotoxic activities of the extracts of Celtis australis L. and Celtis occidentalis L. leaves, which were attributed to the polar n-butanol fractions and the major isolated flavonoid 2″-galactosylvitexin.     

Evaluation of Ethanol and Aqueous extracts of Cinnamomum verum Leaf Galls for Potential Antioxidant and Analgesic activity

In the present study, ethanol and aqueous extracts of leaf galls of Cinnamomum verum were prepared to evaluate the antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay and superoxide radical scavenging assay with ascorbic acid as a standard, and analgesic activity by tail immersion test and acetic acid-induced writhing test methods using diclofenac sodium as the reference drug. Swiss albino mice maintained under standard laboratory conditions were used for analgesic tests. In the 2,2-diphenyl-1-picrylhydrazyl assay it was found that the aqueous and the ethanol extract possessed almost equal capacity to inhibit free radicals (IC₅₀=13.3 and 13.53 µg/ml) but found less than ascorbic acid (IC₅₀=9.96 µg/ml). And in superoxide assay the ethanol extract was found to be more potent in scavenging super oxide radicals when compared to ascorbic acid and the aqueous extract (IC₅₀=237.1 and 197.8 µg/ml) with the IC₅₀=119.7 µg/ml. For analgesic activity, ethanol extract showed the maximum time required for response against thermal stimuli (6.75±0.47 s) and maximum % of writhing inhibition (44.57%) when compared to aqueous extract (5.25±0.48 s and 32.61%), whereas diclofenac showed response in 7.25±0.25 s 67.39% inhibition in tail immersion and writhing tests, respectively. These results demonstrate that the ethanol extracts of leaf galls possessed high antioxidant and analgesic activity.     

Evaluation of In Vitro Antioxidant Potential of Cordia retusa

The present study was carried out to investigate the antioxidant potential, total flavonoid and phenolic content in extracts of aerial parts of Cordia retua (Vahl.) Masam. The samples such as ethyl acetate and ethanol extracts were tested using six in vitro models such as 2,2-diphenyl-1-picrylhydrazyl, nitric oxide radical, iron chelating, hydroxyl radical, superoxide radical scavenging activity and total antioxidant activity to evaluate the in vitro antioxidant potential of C. retusa by spectrophotometrically. Total flavonoid and phenolic content in samples were estimated using aluminum chloride colorimetric and Folin-Ciocalteu method. The results were analyzed statistically by the regression method. Half maximal inhibitory concentration (IC₅₀) of the ethanol extract was found to be 596 μg/ml for DPPH, 597 μg/ml for nitric oxide radical, 554 μg/ml for iron chelating, 580 μg/ml for hydroxyl radical, 562 μg/ml for superoxide radical and 566 μg/ml for total antioxidant capacity. Furthermore, the total flavonoid content and total phenolic content of the ethanol extract were found to be 2.71 mg gallic acid equivalent per gram of extract and 1.86 mg quercetin equivalent per gram of extract, respectively. In all the testing, a significant correlation existed between concentrations of the extract and percentage inhibition of free radicals. The results of the present comprehensive analysis demonstrated that C. retusa possess potent antioxidant activity, high flavonoid and phenolic content. The antioxidant property may be related to the polyphenols and flavonoids present in the extract. These results clearly indicated that C. retusa is effective against free radical mediated diseases as a natural antioxidant.     

Assessment of Bioautography and Spot Screening of TLC of Green Tea (Camellia) Plant Extracts as Antibacterial and Antioxidant Agents

This study was carried out as a prerequisite to evaluate the therapeutic potential of Camellia varieties. The crude extracts of six different plants of green tea Camellia assamica and Camellia sinensis were tested against three Gram-positive and four Gram-negative bacteria using agar disk diffusion method at 50 mg/ml concentration. 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and diphenyl-(2,4,6-trinitrophenyl)iminoazanium free radical scavenging methods were performed to evaluate the antioxidant potential. Phytochemical constituents and trace metals were detected through thin layer chromatography and Inductively Coupled Plasma Atomic Emission Spectrophotometer, respectively. The maximum inhibition of Staphylococcus aureus was recorded by dimethyl sulphoxide extracts of green tea varieties. The measured zone of inhibition of dimethyl sulphoxide extracts by Qimen was (10.00±0.0 mm), Japanese (10.00±0.0 mm), Turkish (10.00±0.0 mm), Indonesian (8.33±1.0 mm), P3 clone (10.00±0.0 mm) and Sri Lankan (10.00±0.0 mm). Maximum scavenging potential activity was found with ethanol, methanol and dimethyl sulphoxide extracts. Spot screening of TLC-developed plates indicated that the presence of active biological compounds such as flavonoids, proteins, phenols, alkaloids and glycosides also exhibited strong activity against tested bacterial strains. This study reveals the potential biological activities of Camellia assamica and Camellia sinensis having massive phytochemical constituents and trace elements.     

Antidiabetic and Free Radicals Scavenging Potential of Euphorbia hirta Flower Extract

The present study was carried out to evaluate antidiabetic and in vitro free radicals scavenging effects of flower extract of Euphorbia hirta. The ethanolic and petroleum ether extracts (250 and 500 mg/kg) were orally tested for 21 days in alloxan induced diabetic mice and blood glucose level was measured with glucometer. Administration of extract resulted in significant reduction in serum cholesterol, triglycerides, creatinine, urea, alkaline phosphatase levels but high density lipoprotein levels and total proteins were found to be increased after treatments. Free radicals scavenging effect of ethanolic extract was also evaluated by various antioxidant assays, including 1, 1-diphenyl-2-picryl hydrazyl free radical scavenging activity, superoxide anion radical scavenging, nitric oxide scavenging, and reducing power assay. It was compared with standard antioxidants compounds such as butylated hydroxyl anisole and ascorbic acid. All the extracts showed antioxidant activity in all the tested methods.     

Antioxidant,free radical scavenging activities of Salvia brachyantha and its protective effect against oxidative cardiac cell injury

In this study, antioxidant and free radical scavenging activities of an endemic Salvia species (Salvia brachyantha (Bordz) probed. was assessed in vitro using 1,1-diphenyl-2-picryhydrazyl (DPPH) radical, β-carotene linoleic acid, superoxide anion radical, hydroxyl radical, and reducing power assays. Regarding our data, the plant extract exhibited antioxidant and radical scavenging activities at different magnitudes of potency. In addition, this study was undertaken to assess whether methanol extract of S. brachyantha could increase the endogenous antioxidant enzymes in cells, and where such increased cellular defences could provide protection against oxidative cell injury. Pre treatment of rat heart cell lines with 100 μg/ml of plant extract for 24 h significantly prevented cell damage and enhanced activity of antioxidant enzymes induced by a treatment with xanthine/xanthine oxidase. Increased reactive oxygen species and cell apoptosis induced by xanthine/xanthine oxidase was dose-dependently prevented when cells were pre treated for 24 h with plant extract. These results indicated that S. brachyantha could protect against cell injury via induction of the antioxidant enzyme defences. The extract of this plant might be valuable antioxidant natural sources and seemed to be applicable in both healthy medicine and food industry.     

Polyphenolics from various extracts/fractions of red onion (Allium cepa) peel with potent antioxidant and antimutagenic activities

In order to determine antioxidant activity, the five extracts/fractions of red onion peel were studied for their total content of phenolics (TPC), flavonoids (TFC), antioxidant activity (AOA), free radical scavenging activity (FRSA), assayed by DPPH radical in the terms of anti-radical power (ARP) and reducing power (RP), expressed as ascorbic acid equivalents (ASE)/ml. High TPC (384.7 ± 5.0 mg GAE/g), TFC (165.2 ± 3.2 mg QE/g), AOA (97.4 ± 7.6%), ARP (75.3 ± 4.5) and RP (1.6 ± 0.3 ASE/ml) were found for the ethyl acetate (EA) fraction. EA fraction had markedly higher antioxidant capacity than butylated hydroxytoluene (BHT) in preventive or scavenging capacities against FeCl₃-induced lipid peroxidation, protein fragmentation, hydroxyl (site-specific and non-site-specific), superoxide anion and nitric oxide radicals. EA fraction also showed dose dependent antimutagenic activity by following the inhibition of tobacco-induced mutagenicity in Salmonella typhimurium strains (TA102) and hydroxyl radical-induced nicking in plasmid pUC18 DNA. HPLC and MS/MS analysis showed the presence of ferulic, gallic, protocatechuic acids, quercetin and kaempferol. The large amount of polyphenols contained in EA fraction may cause its strong antioxidant and antimutagenic properties. This information shows that EA fraction of red onion peel can be used as natural antioxidant in nutraceutical preparations.