Excellent Free Radical Scavenging Research Articles

Chitosan biopolymer promotes yield and stimulates accumulation of antioxidants in strawberry fruit.

Strawberry is a well-known source of natural antioxidants with excellent free radical scavenging capacity. This study determined the effects of chitosan application in field condition on plant growth, fruit yield and antioxidant activities in strawberry fruit. Foliar applications of chitosan on strawberry significantly increased plant growth and fruit yield (up to 42% higher) compared to untreated control. Increased fruit yield was attributed to higher plant growth, individual fruit weight and total fruit weight/plant due to the chitosan application. Surprisingly, the fruit from plants sprayed with chitosan also had significantly higher contents (up to 2.6-fold) of carotenoids, anthocyanins, flavonoids and phenolics compared to untreated control. Total antioxidant activities in fruit of chitosan treated plants were also significantly higher (ca. 2-fold) (p< 0.05) than untreated control. To the best of our knowledge, this is the first report of chitosan applied on field plants providing significant improvement of both yield and health benefiting biochemical contents in strawberry fruit. Further study on the elucidation of mechanisms involved with enhancement of growth, yield and biochemical contents by chitosan is needed to promote sustainable production of strawberry.

The new ether derivative of phenylpropanoid and bioactivity was investigated from the leaves of Piper betle L.

A new ether derivative of phenylpropanoid compound, γ-(γ′-isohydroxychavicol)-chavicol octanyl ether (K1) along with one known phenylpropanoid named allyl-pyrocatechol or hydroxychavicol (2) were isolated from Piper betle var. kali collected from Tumluk district, West Bengal India. We first report the presence of compound K1 in the genus Piper. Their structures were established on the basis of various spectroscopic analyses. Compounds K1 and 2 showed excellent antioxidant DPPH free radical scavenging activity with IC50 values of 4.61 and 4.12 µg/mL compared to ascorbic acid as a standard antioxidant drug with IC50 value of 3.42 µg/mL, respectively. Evaluation of in vitro cytotoxic activities of compounds K1 and 2 showed significant effects against human oral cancer cell lines (AW13516 and AW8507), human hepatoma cell lines (HEPG2 and PLC-PRF-5) and a human pancreatic cell line (MIA-PA-CA-2), compared to Doxorubicin® as a standard cytotoxic drug with GI50 values of <10 and 18.18 µg/mL.

UPLC-DAD quantification of chemical constituents of Potentilla atrosanguinea roots and their antioxidant activity.

Potentilla atrosanguinea, native to Himalayan region, is well known for its curative effects in traditional medicinal system. An ultra performance liquid chromatography-diode array detection method for the quantification of constituents of root part of P. atrosanguinea has been developed along with antioxidant activity evaluation. A simple and sensitive quantification method developed for seven compounds however only four compounds; p-coumaric acid (4), rutin (7), tiliroside (14) and kaempferol (16) were quantified as others were in lesser amount. Syringic acid and quercetin were found in trace amount whereas chlorogenic acid was absent in the ethanol extract of roots of P. atrosanguinea. Total polyphenolic and flavonoid contents were determined to be 21.75mg of gallic acid equivalent and 8.57mg of quercetin equivalent per gram of dry plant material, respectively. Antioxidant activity of extract was assessed using three assays; 2,2'-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP). The IC50 values; 35.75μg/ml and 30.35μg/ml by DPPH and ABTS assays for ethanolic extract showed excellent free radical scavenging potential of its root part. The ferric reducing ability (FRAP) value, 26.67mg of ascorbic acid per gram also indicated its higher antioxidant potential.

The Substituent Effect on the Radical Scavenging Activity of Apigenin.

Flavonoids widely found in natural foods are excellent free radical scavengers. The relationship between the substituent and antioxidative activity of flavonoids has not yet been completely elucidated. In this work, the antioxidative activity of apigenin derivatives with different substituents at the C3 position was determined by density functional theory (DFT) calculations. The bond dissociation enthalpy (BDE), ionization potential (IP), and proton affinity (PA) were calculated. Donator acceptor map (DAM) analysis illustrated that the studied compounds are worse electron acceptors than F and also are not better electron donors than Na. The strongest antioxidative group of apigenin derivatives was the same as apigenin. Excellent correlations were found between the BDE/IP/PA and Hammett sigma constants. Therefore, Hammett sigma constants can be used to predict the antioxidative activity of substituted apigenin and to design new antioxidants based on flavonoids. In non-polar phases, the antioxidative activity of apigenin was increased by the electron-withdrawing groups, while it was reduced by the electron-donating groups. Contrary results occurred in the polar phase. The electronic effect of the substituents on BDE(4′-OH), BDE(5-OH), PA(4′-OH), and IP is mainly controlled by the resonance effect, while that on BDE(7-OH), PA(5-OH), and PA(7-OH) is governed by the field/inductive effect.

Free radical scavenging activity and cytotoxicity assay of Cissus sicyoides berries

BACKGROUND: The leaves of Cissus sicyoides has been utilized in traditional medicine. The berries however are underutilized and do not appear to be widely consumed. OBJECTIVE: This study was undertaken to further evaluate the antioxidant properties of C. sicyoides berries. METHODS: The free radical scavenging activity and IC50 value (inhibitory concentration) of Cissus sicyoides berries was determined utilizing the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Aqueous two-phase partitioning was utilized for preliminary purification of phenylalanine ammonia-lyase (PAL). PAL activity was determined using an endpoint spectrophotometric assay. The cytotoxicity of the berries was assessed by use of the Brine shrimp assay. RESULTS: C. sicyoides berries exhibit excellent free radical scavenging activity with an IC50 value of 0.99 mg/mL which is intermediate to that of raspberries and blackberries. The berries are a potential source of PAL with enzyme activity of 0.10±0.01 U/mg protein. CONCLUSION: Preliminary investigations suggest that the fruits are non toxic and may be utilized as a source of antioxidants. It is evident that the plant is a good source of bioactive compounds with significant potential for food, beverage and medical applications.

Gallic Acid Protects 6-OHDA Induced Neurotoxicity by Attenuating Oxidative Stress in Human Dopaminergic Cell Line.

Gallic acid is one of the most important polyphenolic compounds, which is considered an excellent free radical scavenger. 6-Hydroxydopamine (6-OHDA) is a neurotoxin, which has been implicated in mainly Parkinson's disease (PD). In this study, we investigated the molecular mechanism of the neuroprotective effects of gallic acid on 6-OHDA induced apoptosis in human dopaminergic cells, SH-SY5Y. Our results showed that 6-OHDA induced cytotoxicity in SH-SY5Y cells was suppressed by pre-treatment with gallic acid. The percentage of live cells (90%) was high in the pre-treatment of gallic acid when compared with 6-OHDA alone treated cell line. Moreover, gallic acid was very effective in attenuating the disruption of mitochondrial membrane potential, elevated levels of intracellular ROS and apoptotic cell death induced by 6-OHDA. Gallic acid also lowered the ratio of the pro-apoptotic Bax protein and the anti-apoptotic Bcl-2 protein in SH-SY5Y cells. 6-OHDA exposure was up-regulated caspase-3 and Keap-1 and, down-regulated Nrf2, BDNF and p-CREB, which were sufficiently reverted by gallic acid pre-treatment. These findings indicate that gallic acid is able to protect the neuronal cells against 6-OHDA induced injury and proved that gallic acid might potentially serve as an agent for prevention of several human neurodegenerative diseases caused by oxidative stress and apoptosis.

Phytochemical screening and In-vitro antioxidant activity of &lt;em&gt;Centella asiatica&lt;/em&gt; extracts

&lt;p&gt;&lt;em&gt;Centella asiatica&lt;/em&gt; also known as &lt;em&gt;mandukparni &lt;/em&gt;or Indian pennywort or &lt;em&gt;jalbrahmi&lt;/em&gt;, which has been used as a medicine in the Ayurveda from ancient times and mentioned in many classical texts of Ayurveda. &lt;em&gt;Centella asiatica&lt;/em&gt; has long been used to improve memory and cognitive function.&lt;/p&gt;&lt;p&gt;The study aimed to identify the phytochemicals present in different solvent extracts of &lt;em&gt;Centella asiatica &lt;/em&gt;(i.e. PECA- Petroleum ether extract of &lt;em&gt;C. asiatica, &lt;/em&gt;CCA- Chloroform extract of &lt;em&gt;C. asiatica, &lt;/em&gt;EACA- Ethyl acetate extract of &lt;em&gt;C. asiatica,&lt;/em&gt; ECA- Ethanolic extract of &lt;em&gt;C. asiatica, &lt;/em&gt;HACA- Hydro-alcoholic extract of &lt;em&gt;C. asiatica&lt;/em&gt;)&lt;em&gt; &lt;/em&gt;and evaluate the respective in-vitro antioxidant potentials. &lt;em&gt;&lt;/em&gt;&lt;/p&gt;&lt;p&gt;The phytochemical screening of extracts was done with standardized procedures and the antioxidant potential of different solvent extracts of &lt;em&gt;Centella asiatica&lt;/em&gt; was assessed by its free radical scavenging activity 2, 2-diphenyl -1- picrylhydrazyl (DPPH) as well as hydrogen peroxide scavenging assay respectively for reducing capability.&lt;/p&gt;&lt;p&gt;In all different solvent extracts of &lt;em&gt;C. asiatica&lt;/em&gt; revealed excellent free radical scavenging activity as revealed by 2-2- diphenyl-1-picryl-hydrazyl (DPPH) assay with EC&lt;sub&gt;50&lt;/sub&gt; values for ECA=128.752±1.85 μg/ml, HACA=274.884±1.21 μg/ml and hydrogen peroxide assay against the standard (Butylated hydroxytoluene) BHT, with the EC&lt;sub&gt;50&lt;/sub&gt; values ECA=429.69±0.92 μg/ml HACA=458.08±0.58 μg/ml while rest solvent extracts shown very less antioxidant activity.&lt;/p&gt;&lt;p&gt; The present study indicates that the &lt;em&gt;Centella asiatica&lt;/em&gt; extracts have good antioxidant activity which can be used in stress and anxiety and also a good source to be used as natural drugs.&lt;/p&gt;

Characterization, antioxidativity, and anti-carcinoma activity of exopolysaccharide extract from Rhodotorula mucilaginosa CICC 33013

The water-soluble exopolysaccharide REPS2-A was isolated and characterized from R. mucilaginosa CICC 33013. REPS2-A was composed of galactose, arabinose, glucose, and mannose at a molar ratio of 63.1:0.2:18.3:18.3, respectively, with a molecular weight of 7.125×106Da. Based on FT-IR, NMR, and methylation analysis, REPS2-A was identified to be a highly branched polysaccharide with a backbone of (1→3)-linkedGal with Man, Gal, and Ara terminals. The branches were identified as (1→2)-linked Glc, (1→4)-linked Man, (1→3)-linked Glc, (1→4,6)-linked Man, and (1→2,3,4)-linked Ara. In addition, REPS2-A exhibited excellent free radical scavenging (DPPH, ABTS, and reducing power) and antitumor activities. These results indicate its activity against growth of the human hepatocarcinoma cell HepG2 with IC50 values of 1.0mg/mL, compared to lower cytotoxic effects on normal human hepatocyte cell L02. Studying the underlying mechanisms indicated that REPS2-A induced both dose- and time-dependent cell cycle arrest at the G1/S phase.

Protective Role of Acacia Nilotica Extracs and Silymarin against Mutagenic and Hepatic Injuries Induced by 2-Butoxyethanol in Male Mice

2-Butoxyethanol (2-BE) is a clear colorless liquid that smells like ether. It is used as a solvent in spray lacquers, varnishes, varnish removers, herbicides, liquid soaps, cosmetics, industrial and household cleaners, and dry-cleaning compounds. 2-BE causes cellular damage via formation of reactive oxygen species. Acacia nilotica (A.nilotica) leaf extract exhibited significant antimutagenic and DNA-protective effects against oxidative damage due to the presence of alkaloids, volatile essential oils, phenols and phenolic glycosides; it is considered an excellent free radical scavenging antioxidant owing to the high number of hydroxyl groups. Silymarin (SIL) is a standardized mixture of antioxidant flavonolignans (silybin and silibinin). Silybum marianum (Milk thistle) family Asteraceae is an ancient medicinal plant from which SIL is extracted. It is a free radical scavenger and a membrane stabilizer that prevents lipid peroxidation. In the present study, we investigated the effects of extracts of A.nilotica leaves and SIL on the toxicity of 2-BE. Materials and Methods: 2-BE was given orally to male albino mice for 28 days at dose (450μl/kg b.wt). A. nilotica leaf extract (25 mg/kg b.wt) was dissolved in water and was administered orally for 14 days prior to 28 days treatment of 2-BE and during the 28 days. Also SIL (20 mg/kg b.wt) was administered orally for 14 days prior to 28 days treatment of 2BE and during the 28 days. Result: In the present work, genotoxic effects were induced by 2-BE through oral administration, and the protective effect of A. nilotica and SIL are studied. 2-BE induced a significant increase in the structural as well as numerical chromosomal aberrations. The frequency of chromosomal aberrations showed significant decrease when mice treated with A. nilotica extract and SIL. Also, there were significant increases in micronuclei. A. nilotica extract and SIL administration significant decreases micronuclei induced by 2-BE. However 2-BE induced a significant decrease in mitotic index. Administration of both A. nilotica extract and SIL significant increase mitotic index in mice treated with 2-BE. Exposure of mice to 2-BE caused significant changes in the hematological paramters as well as significant increases in the activities of serum enzymes alanine aminotransferases (ALAT), aspartate aminotransferases (ASAT) and alkaline phosphatase (ALP). Also, 2-BE induced a significant decrease in the content of liver reduced glutathione (GSH), however, induced a significant increase in the level of hepatic lipid peroxidation end product (MDA) of male mice. Co-administration of both A. nilotica extract and SIL to 2-BE-intoxicated mice ameliorated the above-mentioned parameters. Conclusion: 2-BE induced mutagenic and liver injury in male mice. A.nilotica and SIL are found to reduce the percentage of chromosomal aberration and micronuclei cells as they are a powerful antioxidant, they are able to scavenger reactive oxygen species (free radicals) formed by 2-BE in the cells, these free radicals damage DNA and hence cause defects in the chromosomes. A. nilotica extract and SIL could be used as a protective agent against mutagenic and hepatic injuries resulting from 2-BE. The protective action ofSILis more effective than A. nilotica.

Poly(2-hydroxyethylmethacrylate-co-2-folate ethylmethacrylate) and Folic acid/Poly(2-hydroxyethylmethacrylate) Solid Solution: Preparation and Drug Release Investigation

ABSTRACTPoly(2-hydroxyethylmethacrylate-co-2-folatethylmethacrylate) was synthesized by free radical polymerization of 2-hydroxyethylmethacrylate with 2-folatethylmethacrylate and folic acid/poly(2-hydroxyethylmethacrylate) solid solutions was prepared by mixing folic acid with poly(2-hydroxyethylmethacrylate) using the solution casting method. The structure and the homogeneity distribution of folic acid in the polymer matrix are characterized by different methods. The diffusion behaviors of water and folic acid through poly(2-hydroxyethylmethacrylate-co-2-folatethylmethacrylate) and poly(2-hydroxyethylmethacrylate) matrixes were found obey to the Fick models. The in vitro cytotoxicity assessed by microculture tetrazolium test assay and the antioxidant activity of poly(2-hydroxyethylmethacrylate-co-2-folatethylmethacrylate) systems determined by 1,1-diphenyl-2-picryl-hydrazyl method revealed no significant toxicity of these systems and has excellent free radical scavenger property which can be as safe candidate in drug-carrier system. The solubility enhancement of folic acid in different pH media is also investigated and the results obtained reveal a maximum of 399–400 mg L−1. The release dynamic of folic acid from the poly(2-hydroxyethylmethacrylate-co-2-folatethylmethacrylate) containing 5 mol% of folic acid and that from folic acid/poly(2-hydroxyethylmethacrylate) system containing 10 mol% of folic acid have the best intestine/stomach ratio.

Synthesis and Antioxidant Properties of 5,6,7,8-Tetrahydroxyflavone

Flavones are a group of plant secondary metabolites with multiple biological properties. In the present study, 5,6,7,8-tetrahydroxyflavone (5,6,7,8-THF) was synthesized and characterized. In vitro antioxidant study, the effect of 5,6,7,8-THF on total antioxidant activity, reducing power, DPPH radical scavenging, ABTS radical scavenging, superoxide radical scavenging, hydroxyl radical scavenging, nitric oxide radical scavenging, and ferrous chelating activities was examined. According to the results, 5,6,7,8-THF showed excellent free radical scavenging effect and reducing power but weak the ferrous chelating activity. In conclusion, 5,6,7,8-THF can be regarded as an excellent source of antioxidants.

In vitro Antioxidant and Antiproliferative Activities of Various Solvent Fractions from Clerodendrum viscosum Leaves.

Background:Free radicals such as reactive oxygen and nitrogen species, generated in the body, play an important role in the fulfillment of various physiological functions but their imbalance in the body lead to cellular injury and various clinical disorders such as cancer, neurodegenaration, and inflammation.Objective:The objective of this study is to fight this problem, natural antioxidant from plants can be considered as possible protective agents against various diseases such as cancer which might also modify the redox microenvironment to reduce the genetic instability. This study was designed to evaluate the antioxidant and antiproliferative potential of Clerodendrum viscosum fractions against various carcinomas.Materials and Methods:In this present study, 70% methanolic extract of C. viscosum leaves have been fractionated to obtain hexane, chloroform, ethyl acetate, butanol, and water fractions, which were tested for their antioxidant and anticancer properties.Results:It was observed that chloroform and ethyl acetate fractions showed good free radical scavenging properties as well as inhibited the proliferation of human lung cancer (A459), breast (MCF-7), and brain (U87) cells. Moreover, they arrested the cell cycle at G2/M phase of breast and brain cancer. These inhibitory effects were further confirmed by bromodeoxyuridine uptake imaging. Phytochemical investigations further indicate the presence of tannic acid, quercetin, ellagic caid, gallic acid, reserpine, and methyl gallate which might be the reason for these fractions’ antioxidant and antiproliferative activities.Conclusion:Clerodendrum viscosum leaf chloroform and Clerodendrum viscosum leaf ethyl acetate fractions from C. viscosum showed good reactive oxygen species and reactive nitrogen species scavenging potential. Both the fractions arrested cell cycle at G2/M phase in MCF-7 and U87 cells which lead to induce apoptosis.SUMMARY Crude extract of Clerodendrum viscosum leaves was fractionated using different solventsAmong them, chloroform and ethyl acetate fractions exhibited excellent free radical scavenging propertiesThe same fractions inhibited the proliferation of human lung cancer (A459), breast (MCF-7), and brain (U87) cellsChloroform and ethyl acetate fractions arrested the cell cycle at G2/M phase of breast and brain cancerPhytochemical investigations further indicate the presence of several bioactive principles present in them. Abbreviations used: CVLME: Clerodendrum viscosum leaf methanolic extract; CVLH: Clerodendrum viscosum leaf hexane; CVLC: Clerodendrum viscosum leaf chloroform; CVLE: Clerodendrum viscosum leaf ethyl acetate; CVLB: Clerodendrum viscosum leaf butanol; CVLW: Clerodendrum viscosum leaf water; BrdU: Bromodeoxyuridine; WST-1: Water soluble tetrazolium salt.

Antioxidant and Cholinesterase Inhibitory Activities of Ethyl Acetate Extract of Terminalia chebula: Cell-free In vitro and In silico Studies.

Background:Alzheimer's disease (AD) is a progressive neurodegenerative disorder clinically characterized by memory loss and impaired cognitive function. Cholinergic enzyme deficiency and oxidative stress are the two major factors implicated in the pathogenesis of AD. The symptomatic treatment, as of now, is the use of cholinesterase inhibitors toward cholinergic “downturn.” Therefore, there is a search for compounds that will be useful in focused therapies. There has been suggestion that Terminalia chebula fruit would be a potential source.Objective:To assess the anticholinesterase and antioxidant activities of T. chebula fruit which is widely practiced in the Ayurvedic medicines for memory enhancement.Materials and Methods:Ethyl acetate extract of T. chebula fruit (TCEA) was subjected to phytochemical investigation of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities and cell-free antioxidant activity. TCEA was further subjected to gas chromatography-mass spectrum (GC-MS) analysis. The bioactive compounds were analyzed for molecular docking with AChE and BuChE proteins.Results:TCEA exhibited potent AChE and BuChE inhibitory activities comparable to the standard drug donepezil. In vitro cell-free antioxidant assays demonstrated that TCEA possesses excellent free radical scavenging activity, reducing power, and potent metal-chelating activity. Total polyphenolic content of TCEA was 596.75 ± 0.35 µg gallic acid equivalents/mg of extract, which correlates with the antioxidant activity of TCEA. Molecular docking of compounds expounded in GC-MS analysis for AChE and BuChE enzyme activities revealed that methyl N-(N-benzyloxycarbonyl-beta-l-aspartyl)-beta-d-glucosaminide as the most potent compound with good predicted activities.Conclusion:Overall, the results revealed that the bioactive molecule methyl N-(N-benzyloxycarbonyl-beta-l-aspartyl)-beta-d-glucosaminide present in TCEA is a potential depressant for the treatment of AD and related neurodegenerative disorders.SUMMARY The present study was carried out to assess the neuroprotective effect of Terminalia chebula fruit and its phytoconstituent. Phytochemical analysis of fruit ethyl acetate extract of T. chebula (TCEA) showed the presence of alkaloid, cardiac glycoside, and tannin. TCEA showed potent acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities when compared to standard drug donepezil. Results of in vitro antioxidant assays revealed excellent free radical scavenging activity, reducing power, and potent metal-chelating activity. Gas chromatography-mass spectrum analysis illustrated the presence of 22 active compounds, among which methyl N-(N-benzyloxycarbonyl-beta-l-aspartyl)-beta-d-glucosaminide exhibited potent AChE and BuChE inhibition analyzed through in silico studies. Abbreviations used: AD: Alzheimer's disease; TCEA: Ethyl acetate extract of Terminalia chebula; GC-MS: Gas chromatography-mass spectrum; ROS: Reactive oxygen species; RNS: Reactive nitrogen species; AChE: Acetylcholinesterase; BuChE: Butyrylcholinesterase; NFT: Neurofibrillary tangles; Aμ: μ-amyloid; NSAIDS: Nonsteroidal anti-inflammatory drugs; FDA: Food and Drug Administration; RT: Room temperature; HCl: Hydrochloric acid; ATCI: Acetylthiocholine iodide; BTCI: Butyrylthiocholine iodide; BHT: Butylated hydroxytoluene; DPPH: 2,2-diphenyl-1-picrylhydrazyl; TCA: Trichloroacetic acid; GAE: Gallic acid equivalent; NICT: National Institute of Information and Communications Technology; 3D: Three-dimensional; PDB: Protein data bank; OPLS: Optimized potentials for liquid simulations; XP: Extra precision; SD: Standard deviation; ANOVA: Analysis of variance; EDTA: Ethylenediaminetetraacetic acid.

Nitrobacter sp. extract mediated biosynthesis of Ag2O NPs with excellent antioxidant and antibacterial potential for biomedical application.

In this study, extracellular extract of plant growth promoting bacterium, Nitrobacter sp. is used for the bioconversion of AgNO3 (silver nitrate) into Ag2O (silver oxide nanoparticles). It is an easy, ecofriendly and single step method for Ag2O NPs synthesis. The bio-synthesized nanoparticles were characterized using different techniques. UV-Vis results showed the maximum absorbance around 450 nm. XRD result shows the particles to have faced centered cubic (fcc) crystalline nature. FTIR analysis reveals the functional groups that are involved in bioconversion such as C-N, N-H and C=O. Energy-dispersive X-ray spectroscopy (EDAX) spectrum confirms that the prepared nanoparticle is Ag2O NPs. Particle size distribution result reveals that the average particle size is around 40 nm. The synthesized Ag2O NPs found to be almost spherical in shape. Biosynthesized Ag2O NPs possess good antibacterial activity against selected Gram positive and Gram negative bacterial strains namely Salmonella typhimurium, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae when compared to standard antibiotic. In addition, Ag2O NPs exhibits excellent free radical scavenging activity with respect to dosage. Thus, this study is a new approach to use soil bacterial extract for the production of Ag2O NPs for biomedical application.

In vitro and In vivo Antioxidant, Anti-hyperlipidemic Properties and Chemical Characterization of Centella asiatica (L.) Extract.

The study aimed to identify the phenolic compounds present in Centella asiatica (L.) (C. asiatica) extract and evaluate the respective antioxidant potential as well as its cholesterol-lowering effects in the experimental animal model. Herein, the antioxidant potential of extracts was assessed by its free radical scavenging activity such as 2, 2-diphenyl -1- picrylhydrazyl as well as reducing capability. The anti-hyperlipidemic effects of C. asiatica extract (CAE) were evaluated in high cholesterol-fed (HCF) rats for 4 weeks, where different concentrations of extracts (0.25, 0.5, and 1 g/kg/day) were orally administrated daily. Lipid and antioxidant profiles, including total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and superoxide dismutase (SOD), together with the indices of hepatic functions were also examined. C. asiatica revealed excellent free radical scavenging activity as revealed by 2-2- diphenyl-1-picryl-hydrazyl (DPPH) assay, with the IC50 values (9.62 ± 0.88 μg/mL). Furthermore, C. asiatica extracts and fenofibrate remarkably lowered the level of TC, TG, LDL-C, and showed elevated levels of HDL-C, SOD. The histopathological observations further demonstrated clear differentiation and structural changes in liver of HCF and CAE treated group. Furthermore, gulonic acid, ferulic acid, kaempferol, chlorogenic acid, and asiatic acid were identified to be the major components which might be responsible for the antioxidant activity of the C. asiatica extract as evidenced from an ultra-high performance liquid chromatography–mass spectrometer. Taken together, these results signifies the excellent antioxidant and anti-hyperlipidemic properties of C. asiatica leaf extracts, which might be useful for the treatment of oxidative-stress related diseases such as hyperlipidemia.

Chemical composition and biological activities of essential oil and extracts from Ocimum sanctum

ABSTRACTThe objective of the present research work was to evaluate the antioxidant, antimicrobial and antimalarial activities of essential oil and various extracts from O. sanctum. Gas chromatography-mass spectrometry analysis identified the following major compounds with their quantification as: eugenol (22.0%), β-elemene (19.2%), β-caryophyllene (19.1%), and Germacrene D (5.03%). HPLC analysis of O. sanctum extracts revealed that gallic acid, chlorogenic acid, p-hydroxy benzoic acid, caffeic acid, vanillic acid, p-coumeric acid, sinapic acid, and ferulic acid were the important phenolic acids. The methanol extract exhibited highest level of total phenolic (1.36 g/100 g dry plant material) and total flavonoid (0.67 g/100 g dry plant material) followed by ethanol and n-hexane extracts. The oil and extracts exhibited excellent free radical scavenging potential as measured by 2,2-diphenyl-1-picrylhydrazyl radical free radical-scavenging ability, and antioxidant activity as measured by inhibition of linoleic acid oxidation. Essential oil, n-hexane, methanol, and ethanol extracts exhibited moderate antimalarial potential in term of anti-haem biocrystallization activity. In the resazurin microtitre plate and disc diffusion assays, the essential oil of O. sanctum showed better antibacterial activity than various extracts. The results of the present investigation demonstrated significant (p < 0.05) variations in the antioxidant, antimicrobial, and antimalarial activities of essential oil and extracts from O. sanctum.

Multifunctional mussel-inspired copolymerized epigallocatechin gallate (EGCG)/arginine coating: the potential as an ad-layer for vascular materials.

Surface properties are considered to be important factors in addressing proper functionalities. In this paper, a multifunctional mussel-inspired coating was prepared via the direct copolymerization of epigallocatechin gallate (EGCG) and arginine. The coating formation was confirmed by X-ray photoelectron spectroscopy and Fourier transform infrared spectra. The EGCG/arginine coating contained diverse functional groups like amines, phenols and carboxyls, whose densities were also tunable. Such mussel-inspired coating could also be applied as an ad-layer for its secondary reactivity, demonstrated by quartz crystal microbalance technique. Moreover, the tunable surface density of phenols showed potential ability in modulating endothelial cell and smooth muscle cell viability. The coatings rich in phenols presented excellent free radical scavenging property. Current results strongly indicated the potential of EGCG/arginine coatings to be applied as an ad-layer for vascular materials.

Role of Quercetin against 2-Butoxyethanol Induced Micronucleus and Chromosome Aberrations in Mice

EGBE is also known as 2-butoxyethanol (2BE). EGBE is widely used as a solvent in various applications, such as in surface coatings, spray lacquer, quick-dry lacquers, enamels, varnishes, varnish removers, latex paint, metal cleaners, and in commercially available cleaning products. 2-Butoxyethanol causes cellular damage via formation of reactive oxygen species. Quercetin, a flavonol group of plant flavonoid, has generated interest because of its potential antioxidant, anti-proliferative, chemoprotective and anti-inflammatory properties. Quercetin exhibited significant antimutagenic and DNA-protective effects against oxidative damage due to the presence of hydroxyl groups in the molecule; it is considered an excellent free radical scavenging antioxidant owing to the high number of hydroxyl groups. Materials and Methods: 2BE was given orally to male mice for seven days at two doses (450µl &900µl/kg b.w.). Quercetin was dissolved in corn oil. The animals in positive control group were treated with only corn oil. Quercetin (20 mg/kg b.w.) was administered orally for 7 days prior to 7 days treatment of 2BE for the two doses. Quercetin (20 mg/kg b.w.) was also administered for 14 days (7 days before and 7 days during the period of treatment with two doses of 2BE). Result: the two doses of 2BEinduced both micronuclei (2.88% and 12.77%) and chromosomal aberration in (50% & 72.8%, respectively) of cells. Quercetin administration lowered the frequency of micronuclei and chromosome aberration. Conclusion: These effects of quercetin are to be taken into consideration while evaluating the possible use of quercetin as a protective agent.

Lanthanide Coordination Polymer Nanoparticles as an Excellent Artificial Peroxidase for Hydrogen Peroxide Detection

Lanthanide coordination polymer nanoparticles (Ln-CPNs) have been recently demonstrated as excellent platforms for biomolecule detection. In this work, we synthesized novel cerium coordination polymer nanoparticles ATP-Ce-Tris CPNs in a simple and quick way using ATP molecules as the biocompatible ligands to Ce(3+) ions in tris(hydroxymethyl)aminomethane hydrochloric (Tris-HCl) solution. In view of the excellent free radical scavenging property of cerium compounds, which is ascribed to the mixed valence state (Ce(3+), Ce(4+)) and the reversible switch from Ce(3+) to Ce(4+), the synthesized ATP-Ce-Tris CPNs was used as artificial peroxidase to selectively and sensitively detect H2O2. The sensing mechanism depends on the oxidation of the fluorescent ATP-Ce(III)-Tris CPNs to nonfluorescent ATP-Ce(IV)-Tris CPNs by H2O2. Compared with those inorganic cerium oxide sensors, this kind of fluoresence ATP-Ce-Tris CPNs sensor needs no additional organic redox dye, such as ABTS (2,20-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), TMB (3,3,5,5-tetramethylbenzidine), or fluorescein as signal molecules. Moreover, such ATP-Ce-Tris CPNs sensor exhibited a more sensitive response to H2O2 with a detection limit down to 0.6 nM, which is 2 orders of magnitude lower than those of cerium oxide sensors. This sensing platform was further extended to the detection of glucose in combination with the specific catalytic effect of glucose oxidase (GOx) for the oxidation of glucose and formation of H2O2.

A strategy for screening active lead compounds and functional compound combinations from herbal medicines based on pharmacophore filtering and knockout/knockin chromatography

Screening and deciphering active natural products of herbal medicines are of great importance for modern drug discovery. In this study, a novel strategy was proposed to rapidly filter ineffective compounds and target the most potential leads. The aim is to answer the key question of what components are responsible for the holistic bioactivity of an herbal product. To support the strategy, the pharmacophore-guided knockout/knockin chromatography was established for the first time. The greatest advantage of this method is that any interesting components could be automatically fished or knocked out. The method validation shows that the herbal extract was accurately reconstructed according to the experimental design. By combining with bioactivity assays, we demonstrated that “functional compound combination (FCC)”, which is the core and indispensable effective part, could be discovered from an herbal medicine and suitable as marker compounds for quality control. The applicable objects of the strategy include single herbs, herbal formulas and commercially herbal preparations. As an illustrative case study, the strategy was successfully applied to simultaneously determine active leads and the FCC in Dan-Qi formula which shows excellent free radical scavenging activity. The potential mechanisms of compounds in Dan-Qi formula reacting with three different free radicals were systematically reported for the first time. This strategy was expected to unveil the mystery of herbal medicines and inspire a natural product-based drug discovery.