Lipid Peroxidation Inhibitory Assay Research Articles

Dextran-Chitosan Composites: Antioxidant and Anti-Inflammatory Properties.

This study presents the development of new formulations consisting of dextran (Dex) and chitosan (Ch) matrices, with fillings such as chitosan stearate (MCh), citric acid, salicylic acid, or ginger extract. These materials were characterized using Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and mechanical tests, and evaluated for antioxidant properties, including scavenging activities, metal chelation, and ferric ion reducing power, as well as anti-inflammatory properties, measuring the binding affinity between serum albumin and the bioactive substances, which can influence their bioavailability, transport, and overall anti-inflammatory effect. Compounds in ginger such as 6-gingerol reduce inflammation by inhibiting the production of inflammatory substances, such as prostaglandin, cytokines, interleukin-1β, and pro-inflammatory transcription factor (NF-κB) and, alongside citric and salicylic acids, combat oxidative stress, stabilizes cell membranes, and promote membrane fluidity, thereby preserving membrane integrity and function. Incorporating chitosan stearate in chitosan:dextran samples created a dense, stiff film with an elastic modulus approximately seventeen times higher than for the chitosan:dextran matrix. The Dex:Ch:MCh sample exhibited low compressibility at 48.74 ± 1.64 kPa, whereas the Dex:Ch:MCh:citric acid:salicylic acid composite had a compact network, allowing for 70.61 ± 3.9% compression at 109.30 kPa. The lipid peroxidation inhibitory assay revealed that Dex:Ch:MCh:citric acid had the highest inhibition value with 83 ± 0.577% at 24 h. The study highlights that adding active substances like ginger extract and citric acid to Dex:Ch composites enhances antioxidant properties, while modified chitosan improves mechanical properties. These composites may have potential medical applications in repairing cell membranes and regulating antioxidant enzyme activities.

A New Class of Water‐Soluble Aryl Sulfonium Decavanadates and Their Antioxidant Activity: Effects of Cluster Reduction and Counter Ion Substitution on Activity

AbstractThe development of biocompatible and water‐soluble inorganic antioxidants is important, given the increasing demand for antioxidants worldwide. Polyoxovanadate (POV) clusters have been extensively explored for several biological applications, but the antioxidant properties of POVs remain largely unexplored. Herein, we developed a series of water‐soluble aryl sulfonium decavanadate ([V10O28]6−) hybrids and studied their antioxidant properties. The hybrids were characterized by several analytical and spectroscopic techniques such as ESI‐MS, XPS, and single‐crystal XRD analyses. The antioxidant properties of these hybrids were explored under native and photochemically reduced conditions using standard in vitro antioxidant assays such as H2O2 scavenging assay, lipid peroxidation inhibitory assay, DPPH radical scavenging assay, and reducing power assay. These analyses showed that these aryl sulfonium POV hybrids exhibit comparable or better antioxidant activities than the parent [V10O28]6− cluster and the standard ascorbic acid in some of the assays studied. The cytotoxicity studies using MG‐63 cells revealed that these hybrids exhibit moderate cytotoxicity. Further, it was found that introducing a phenolic functional group on the counter ion moiety helps to improve the overall antioxidant properties of the POV‐based hybrids. The present study, therefore, reports a series of water‐soluble aryl sulfonium polyoxometalate hybrids‐based antioxidants for the first time. However, more toxicological studies using similar hybrids are required to fully understand the biocompatible nature of these systems before considering their potential biological applications.

Phytochemical Screening, gc-ms Analysis and Antioxidant Activity of Methanol Stem Bark Extract of Cassia Sieberiana DC

The over production of free radicals in the human body is known to cause oxidative stress which plays an important role in the pathogenesis of many diseases. Therefore, the search for natural antioxidants would continue to be a major area of research for many decades. This study was to investigate the in vitro antioxidant activities and to determine the phytochemicals present in Cassia sieberiana. The methanol stem bark extract of C. sieberiana was subjected to phytochemical screening and Gas Chromatography-Mass Spectrometry (GC-MS) analysis. Its antioxidant activities were assayed in vitro using nitric oxide scavenging assay, ferric reducing antioxidant potential assay, lipid peroxidation inhibitory assay and 2-diphenyl-1-picrylhydrazyl scavenging assay. The phytochemical screening of the stem bark extract of C. sieberiana showed saponins, alkaloids, flavonoids, steroids, tannins, phlobatannins, terpernoids, cardiac glycosides, phenolics and reducing sugar. The GC-MS Table revealed that the methanol extract has 51 bioactive compounds with 3-0-Methyl-d-glucose having the highest percentage of 12.16 % while 5.alpha-Androstan-3-beta-ol,4,4-dimethyl- having the lowest percentage of 0.09 %. The antioxidant study showed concentration-dependent radical scavenging activity of the methanol stem bark extract of C. sieberiana. This concentration-dependent result was also observed when compared with ascorbic acid used as the standard drug. The presence of different phytochemicals such as alkaloids, saponins, tannins, phenols, flavonoids, among other things, might be responsible for C. sieberiana antioxidant activity. The study concluded that the methanol stem bark extract of C. sieberiana contains 51 bioactive compounds and showed good antioxidant activity which could be therapeutic in several human diseases. Key words: Cassia sieberiana, Phytochemical, Antioxidant, Pharmaceuticals

New Insights on Hemp Oil Enriched in Cannabidiol: Decarboxylation, Antioxidant Properties and In Vitro Anticancer Effect.

This study aimed to obtain and characterize extracted hemp oil enriched in cannabidiol (CBD) by decarboxylation of cannabidiolic acid (CBDA) and to give new insights into its antioxidant and anticancer effects. Optimization of CBDA decarboxylation in hemp oil was performed, and CBD and CBDA contents and purities were determined by flash chromatography, 1H- and 13C-NMR. The antioxidant properties of CBD-enriched oil were investigated by Fe2+ chelating activity, Fe3+ reducing antioxidant power assay, O2●− scavenging activity, HO● scavenging ability and lipid peroxidation inhibitory assay, and its cytotoxicity, apoptosis- and oxidative stress-inducing effects on NHDF, MeWo, HeLa, HepG2 and HOS cells were determined. The CBD concentration in hemp oil was increased by CBDA soft decarboxylation optimized at 90 °C, for 1 h and the resulting oil was capable of reducing iron, scavenging free radicals and inhibiting lipid peroxidation in cell-free oxidative conditions. CBD-enriched oil promoted NHDF proliferation at up to 15 µg CBD/mL, while inducing apoptosis and ROS production and modulating antioxidant enzymes’ gene expression in cancer cells, being selective for osteosarcoma cells, and induced apoptosis by p53- and ROS-independent mechanisms. CBD-enriched hemp oil demonstrated antioxidant properties in oxidative conditions and promoted normal fibroblasts’ proliferation, while inducing apoptosis and ROS production in cancer cells.

Antioxidant and Anticholinesterase Activities of Some Dialkylamino Substituted 3-Hydroxyflavone Derivatives.

Flavones, are a class of naturally occuring polyphenolic compounds which have 2-phenylchromen-4-one structure. Various studies showed that flavones have several pharmacological activities such as antioxidant, anti-inflammatory, antimicrobial, cytotoxic, antitumour and antiallergic. In the present study, 3-hydroxyflavones also called flavonols, posessing 4'-dialkylamino moiety were synthesized, and their antioxidant and anticholinesterase activities were investigated by comparison with unmodified 3-hydroxflavone. For investigation of antioxidant potential, radical scavenging assays (DPPH•, ABTS+_, O2.-) were used along with CUPRAC and lipid peroxidation inhibitory assays, as well as anticholinesterase activity by Ellman method. The best results were obtained for 4'-N,N-dimethyl flavonol (1) in both antioxidant and anticholinesterase activity tests, possibly due to its least steric hinderance effect. It exhibited remarkable DPPH free radical scavenging activity (2.43±0,09 μg/mL) competing with a standard compound quercetin (2.10±0,10 μg/mL). Moreover, the other tested flavonols also showed high antioxidant activities. Compounds 5 and 6 exhibited close IC50 values to those of compound 1. Antioxidant activity test results were found to be well correlated with anticholinesterase activity test results indicating possible role of antioxidant compounds in the treatment of Alzheimer's disease.

Mitigating effect of Indian propolis against mitomycin C induced bone marrow toxicity.

A major drawback with cancer chemotherapy is its severe toxic effects on non-target tissues. Assessment of natural products for their protective effect against anticancer drugs-induced toxicity is gaining importance in cancer biology. The present study was aimed at assessing the protective effect of hydroethanolic extract of Indian propolis (HEIP) against mitomycin C (MMC)-induced genotoxicity and cytotoxicity. Swiss albino mice were injected with various doses of HEIP (100, 200, 300, 400, 600 and 800mg/kg b. wt., i.p) 1h prior to MMC (8mg/kg, i.p.) injection. The geno- and cyto-toxicities were evaluated in mice by performing bone marrow micronucleus and TUNEL assays. In vitro antioxidant and lipid peroxidation inhibitory assays were carried out to understand the mechanism of the protective effects. The significant increase in the frequency of micronculeated cells (12.51±0.48), apoptotic cells (23.43±1.86) and reduction in P/N ratio (0.69±0.04) compared with control indicated the potential geno- and cytotoxic effects of MMC in bone marrow. Pretreatment with HEIP resulted in the significant recovery of the toxic effects induced by MMC. HEIP at 400mg/kgb. wt. was found to be the optimum dose imparting the maximum protective effects. The in vitro antioxidant and lipid peroxidation inhibitory assays suggest that the extract possesses substantial free radical scavenging activities. In conclusion, HEIP possesses substantial geno- and cyto-protective properties against MMC, which could be mediated through efficient free radical scavenging and inhibitory effect on lipid peroxidation.

Comparative Analysis of Phenolics, Flavonoids, and Antioxidant and Antibacterial Potential of Methanolic, Hexanic and Aqueous Extracts from Adiantum caudatum Leaves.

In the quest for new medicines, the methanolic, hexanic, and aqueous extracts of Adiantum caudatum leaves, obtained by Soxhlet extraction, were analyzed for phenolic and flavonoid contents, and antioxidant and antimicrobial potential. TPCs (total phenolic content) of the methanolic, aqueous and hexanic extracts were 27.7, 21.1, and 16.7 μg of gallic acid equivalents per mL, respectively, while TFCs (total flavonoid content) were 13.2, 11.6, and 10.0 μg of rutin equivalents per mL, respectively. Antioxidant activities of the extracts in reducing power, FRAP (ferric reducing antioxidant power), phosphomolybdate and ABTS assays follow the same order of methanolic ˃ aqueous ˃ hexanic. In the DPPH assay, however, the aqueous extract exhibited a slightly higher antioxidant activity than the methanolic one. Methanol is therefore a better solvent to extract most of the antioxidant components from A. caudatum leaves. In lipid peroxidation inhibitory assay, the extracts showed almost similar behavior and their activity decreased gradually with time. The aqueous extract was the strongest inhibitor after two days, but the hexanic became the most potent after about three days. The antibacterial potential of the extracts was determined against Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. Towards all the microbes, the aqueous extract was the most potent and the hexanic the least. P. aeruginosa was the most susceptible strain, while the aqueous and methanolic extracts exhibited a slightly higher efficacy against this pathogen than the drug amoxicillin. In conclusion, A. caudatum can potentially provide a remedy against disorders caused by oxidative stress and infections.

Phenolic and flavonoid contents and anti-oxidative potential of epicarp and mesocarp of Lagenaria siceraria fruit: a comparative study

ObjectiveTo conduct a comparative analysis of the phenolic and flavonoid contents and anti-oxidative potential of epicarp and mesocarp of Lagenaria siceraria fruit. MethodsThe dried methanolic extracts of mesocarp and epicarp of the fruit and their hexane, chloroform, ethyl acetate, n-butanolic and aqueous fractions were subjected to antioxidant assays including ferric reducing antioxidant potential, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid, reducing power capacity, 2,2-diphenyl-1-picrylhydrazyl, lipid peroxidation inhibitory and phosphomolybdate assays. Total phenolic and flavonoid contents were also determined. ResultsEthyl acetate fractions of epicarp and mesocarp had considerable amounts of phenolics (243.50 and 109.50 μg/mL of gallic acid equivalents, respectively). 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of ethyl acetate fractions of both the plant parts showed higher activity than vitamin C with IC50 (0.75 and 3.91 mg, respectively). In phosphormolybdate assay, the hexane fractions of both the parts showed highest activity [1.16 and 2.99 μg/mL of ascorbic acid equivalents (AAE) for epicarp and mesocarp, respectively], mesocarp being much potent than epicarp. The n-butanolic fraction of mesocarp also showed much higher activity (1.13 μg/mL AAE) than that of epicarp (0.74 μg/mL AAE), while the chloroform and ethyl acetate fractions of epicarp were also considerably potent. In ferric reducing antioxidant potential assay, the chloroform fractions of both the fruit parts were most active. The hexane fractions of both the parts showed highest activity in reducing power assay, epicarp being more potent than mesocarp. In 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid assay, the antioxidant activities of ethyl acetate and chloroform fractions of both the parts were comparable to gallic acid and vitamin C. In lipid peroxidation inhibitory assay, all the samples were moderate to good activity sustainable over the period of 72 h, indicating the presence of both slow and fast releasing antioxidants. ConclusionsThe findings of the study suggest that epicarp is a better source of antioxidants than the mesocarp, and the ethyl acetate fractions of both the parts contain higher contents of antioxidants.

Chromenone and quinolinone derivatives as potent antioxidant agents

The antioxidant activity (AOA) of three different classes of phenolic compounds viz chromen-2-ones, chromen-4-ones, and quinolin-2-ones was systematically studied using DPPH, ABTS, FRAP, and in vitro lipid peroxidation inhibition assays. The effect of incorporation of hydrophobic group on AOA was also studied. In DPPH, ABTS, and FRAP assays, the highest AOA was registered for the dihydroxy chromenones among all the phenolic derivatives. Presence of alkyl group led to reduction in AOA in the above three assays. However, in lipid peroxidation inhibition assay for selected compounds, incorporation of alkyl group led to enhancement in AOA. The AOA of few compounds was observed to be more than three times higher in comparison to standard “Trolox” in lipid peroxidation inhibitory assay.

Stemodin-derived analogues with lipid peroxidation, cyclooxygenase enzymes and human tumour cell proliferation inhibitory activities

A series of analogues, derived from the antiviral and cytotoxic diterpene stemodin, were prepared and evaluated for their lipid peroxidation (LPO), cyclooxygenase enzyme-1 (COX-1) and -2 (COX-2), and tumour cell proliferation inhibitory activities. Oxidation of stemodin produced stemodinone, which was then converted to stemod-12-en-2-one. Reaction of the latter under Petrow conditions (bromine; silver acetate/pyridine) yielded mainly dibrominated abeo-stachanes. Solvolysis of the dibromo compounds gave products of hydrolysis, some with rearranged skeleta. In the lipid peroxidation inhibitory assay three of the compounds exhibited prominent activity. Interestingly, all the analogues showed higher COX-1 enzyme inhibition than COX-2. Although a few of the diterpenes limited the growth of some human tumour cell lines, most compounds induced proliferation of such cells.

An Efficient and Economical MTT Assay for Determining the Antioxidant Activity of Plant Natural Product Extracts and Pure Compounds

Antioxidants scavenge free radicals, singlet oxygen, and electrons in cellular redox reactions. The yellow MTT [3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide] is reduced to a purple formazan by mitochondrial enzymes. NADPH is the basis of established in vitro cell viability assays. An antioxidant assay has been developed utilizing the redox reaction between MTT and selected natural product extracts and purified compounds. This simple, fast, and inexpensive MTT antioxidant assay is comparable with the lipid peroxidation inhibitory assay and can be mechanized to achieve high throughput.

Anti-oxidative Properties of Lipids Extracted from Rainbow Trout (Oncorhynchus mykiss) Fed with Carotenoids and Conjugated Linoleic Acid

A commercial diet supplemented with carotenoids and conjugated linoleic acid was fed to rainbow trout (Oncorhynchus mykiss) for 8 weeks. To investigate the anti-oxidative properties of these compounds, lipids from the muscle and viscera of the fish were subjected to different assays. At <TEX>$10\;{\mu}g/mL$</TEX>, L-ascorbic acid exhibited 95% 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, while the tissue lipids showed little radical scavenging activity. At 50 and <TEX>$100\;{\mu}g/mL$</TEX>, the lipids of the muscles and viscera showed 11.7-22.6% and 11.3-24.9% DPPH radical-scavenging activity, respectively. A lipid peroxidation inhibitory assay using the ferric thiocyanate method was also performed in comparison with <TEX>$\alpha$</TEX>-tocopherol at a concentration of 6.0 mg/mL. Our results indicate that the anti-oxidative property of the lipids in fish muscle, which was 85.2% compared to 85.3% for the visceral lipids, was stronger than that of <TEX>$\alpha$</TEX>-tocopherol (74.3%) following 3 days of storage at <TEX>$40^{\circ}C$</TEX>.

Leaf extracts from Moricandia arvensis promote antiproliferation of human cancer cells, induce apoptosis, and enhance antioxidant activity

The in vitro antiproliferative, apoptotic, and antioxidant activities from leaf extracts of Moricandia arvensis, which are used in traditional cooking and medicines, were investigated. The MTT assay revealed that only TOF (total oligomer flavonoids), ethyl acetate (EA), chloroform (Chl), and petroleum ether (PE) extracts inhibited the proliferation of K562 cells. Apoptosis plays a very important role in the treatment of cancer by promoting the apoptosis of cancer cells and limiting the concurrent death of normal cells. Thus, the possible effects of M. arvensis extracts on the induction of apoptosis in human leukemic cells (K562 cells) were investigated. The electrophoretic analysis of DNA fragmentation confirms that TOF, Chl, PE, and EA extracts provoke DNA fragmentation. Using the lipid peroxidation inhibitory assay, the antioxidant capacity of M. arvensis extracts was evaluated by the ability of each extract to inhibit malondialdehyde formation. It was revealed that EA and TOF extracts are the most active in scavenging the hydroxyl radicals.

Quantification and characterisation of cyclo-oxygenase and lipid peroxidation inhibitory anthocyanins in fruits ofAmelanchier

The levels of bioactive anthocyanins in the fruits of Amelanchier alnifolia, A. arborea and A. canadensis have been determined by HPLC. Cyanidin 3-galactoside (1) was present in the fresh fruit of the three species at concentrations of 155, 390 and 165 mg/100 g, respectively. Cyanidin 3-glucoside (2) was present only in A. alnifolia and A. canadensis at concentrations of 54 and 48 mg/100 g, respectively. The anthocyanins were confirmed by LC-ESI/MS and NMR studies. At 100 ppm, anthocyanin mixtures from the three species inhibited cyclo-oxygenase (COX)-1 and -2 enzymes at 66 and 67%, 60 and 72%, and 51 and 76%, respectively. The positive controls used in the COX assays were aspirin, Celebrex and Vioxx at 180, 1.67 and 1.67 ppm, respectively, and showed 74 and 69%, 5 and 82% and 0 and 85% COX-1 and COX-2 inhibition, respectively. Anthocyanins 1 and 2 and cyanidin (3) inhibited COX-1 enzyme 50.5, 45.62 and 96.36%, respectively, at 100 ppm, whereas COX-2 inhibition was the highest for 3 at 75%. In the lipid peroxidation inhibitory assay, anthocyanin mixtures at 10 ppm from the three species showed activities of 72, 73 and 68%, respectively, compared with 89, 87 and 98% for commercial anti-oxidants butylated hydoxyanisole, butylated hydroxytoluene, and tert-butylhydroxyquinone at 1.67, 2.2 and 1.67 ppm, respectively. At 10 ppm, compounds 1-3 inhibited lipid peroxidation by 70, 75 and 78%, respectively.

Constituents in Easter lily flowers with medicinal activity

Easter lily ( Lilium longiflorum) flowers have been used in traditional medicine for alleviating many ailments. However, the chemical basis of its bioactivity has not been investigated. We have determined bioactive components in Easter lily flowers using lipid peroxidation and cyclooxygenase enzyme inhibitory assays and found to be kaempferol ( 1), kaempferol glycosides ( 2, 3, 4, 8, 9 and 10), quercetin glycosides ( 5, 6 and 7), a regaloside ( 11), a chalcone ( 12) and a fatty acid fraction ( 13). The structures of compounds were determined by NMR, IR, UV/VIS and mass spectroscopic studies. Compound 1 showed the highest COX-1 inhibition (94.1%) followed by 3, 8 and 12 with 38.7, 30.8 and 32.4%, respectively. Only compound 1 inhibited COX-2 enzyme by 36.9% at 80 ppm. In lipid peroxidation inhibitory assay, kaempferol showed 37 and 100 % inhibitions at 1 and 10 ppm, respectively. At 10 ppm, more than 20% inhibition was observed for compounds 4, 7, 10, 11 and 12 and 53% for compound 3. The compounds reported in here are isolated for the first time from Easter lily flowers including novel compounds 10, 11 and 12. Our results suggest that kaempferol and quercetin flavonoids contributed to the anecdotal medicinal properties of Easter lily flowers.