Ascorbic Acid Antioxidant Activity Research Articles

Synthesis and antioxidant properties of novel hybrid molecules containing gallic acid and thiazolidinone moieties

Thiazolidinones, are characterized by a thiazolidine ring structure, have highly biological applications. So, novel hybrid thiazolidinone moieties containing gallic acid were synthesized via cyclo-condensation process or standard Knoevenagel reactions. Hydrazineyl-thiazol-4(5H)-one 2 derivative was synthesized to condensed with benzaldehydes to afford benzylidene thiazolidinone derivatives 3a-c. Also, the product 2 reacted with benzyl bromide or nitro benzyl bromide to give their corresponding methylene active derivatives 4a,b which were readily reacted with aromatic aldehydes to produce 5-arylidene derivatives 5a-f via Knoevenagel reactions. The new thiazolidine derivatives were elucidated according to their spectroscopic and elemental analyses. Two thiazolidinone derivatives 4a,b were elucidated via X-ray analysis. Also, antioxidant activity of the new products were run by DPPH assay and in comparison with reference antioxidants (ascorbic acid and BHT). The results revealed that eight compounds was higher than BHT and was increasing in the following order 4a < 5f < 5a< 3c < 5b < 5d < 3a< 5c. The antioxidant activity of ascorbic acid was higher than all compounds in which compound 5c was very close in its activity with the ascorbic acid.

Comparative study of the chemical composition, antioxidant, and antimicrobial activity of the essential oils extracted from Lavandula abrialis and Lavandula stoechas: in vitro and in silico analysis.

This work aims to add value to the Lavandula genus by identifying the chemical composition, antioxidant, and antimicrobial activities of two species lavender from Oulmès in Morocco; Lavandula abrialis and Lavandula stoechas. The uniqueness lies in the integrated approach that combines in vitro and in silico analyses to assess the biological properties of the essential oils (EO). The objective of this study is to enhance the significance of the Lavandula genus by analyzing the chemical composition, antioxidant properties, and antimicrobial effects of two lavender species found in Oulmès, Morocco: Lavandula abrialis and Lavandula stoechas. The distinctiveness is in the comprehensive methodology that merges in vitro and in silico investigations to evaluate the biological characteristics of the essential oils (EO). The extraction of essential oils (EO) by hydrodistillation from the aerial parts of Lavandula abrialis gave a high yield of essential oils (2.9%) compared to Lavandula stoechas (2.3%). A GC-MS analysis of the chemical composition revealed 56 chemical compounds, with some variation in the predominant components, representing between 99.98% and 100% of the EOs of the studied lavenders. Their antioxidant activity was assessed using the DPPH test. This method revealed that L. stoechas EO has a higher percentage of free radical inhibition than L. abrialis. The IC50 values demonstrate that the antioxidant activity of ascorbic acid is higher (1.62g/mL) than the EOs of tested plants. Noteworthy, the EO of L. stoechas is more potent (12.94g/mL) than that of Lavandula tibialis (34.71g/mL). Regrading, the antibacterial tests, the EO of L. abrialis was particularly active against Staphylococcus aureus BLACT, which is inhibited at a concentration of 6.25g/mL, while L. stoechas EO has a strong effect on Escherichia coli, with a MIC of 1.56g/mL. Concerning the antifungal activity of the EOs, yeasts showed sensitivity toward EOs extracted from both L. tibialis and L. stoechas. Moreover, an in silico study was conducted targeting sarA protein of S. aureus (PDB ID: 2fnp) and NADPH oxidase from Lavandula sanfranciscensis (PDB: 2CDU) and results showed that Ishwarone and Selina-3,7 (11)-diene exhibited highest binding energy with -9.8 and -10.8kcal/mol respectively. Therefore, these two compounds could be used as an antibacterial and antioxidant agents however more experimental and molecular study should be required.

Easy-to-Use Chemiluminescent-Based Assay for a Rapid and Low-Cost Evaluation of the Antioxidant Activity of Cosmetic Products

New cosmetic formulations are continuously requested by the market and the ingredients are constantly evolving. Recently the use of antioxidants has gained success and, in this context, analytical methods able to quickly and easily assess the antioxidant activity of cosmetics would make it possible to carry out analyses on new formulations even within the manufacturing process without the need for specialized laboratories and personnel, thus evaluating directly on-site the effectiveness and the shelf life of products. In this work, a chemiluminescent inhibition assay was developed for determining the total antioxidant activity in cosmetic products. The method was based on the luminol/enhancers/hydrogen peroxide/horseradish peroxidase chemiluminescent system, which generates light signals measurable through simple and compact instrumentation. The formation of the chemiluminescent signal is inhibited by the presence of antioxidant substances while it is restored once all the antioxidant molecules have been oxidized. The time of appearance of the light signal is related to the total antioxidant activity. The assay was carried out exploiting an integrated device comprising a microwell plate coupled with an array of amorphous silicon hydrogenated photosensors enclosed in a mini-dark box. The method was optimized in terms of concentrations and volumes of the required reagents and sample pre-treatment. A calibration curve was generated taking as a reference the antioxidant activity of ascorbic acid obtaining a detection limit of 10 µM. The developed method was applied to cosmetic products currently on the market as well as on spiked samples in order to evaluate the performance of the methods in terms of sensitivity, accuracy, and reproducibility.

Synthesis and Biological Properties of Polyphenol-Containing Linear and Dendrimeric Cationic Peptides.

Natural polyphenols are promising compounds for the pharmacological control of oxidative stress in various diseases. However, low bioavailability and rapid metabolism of polyphenols in a form of glycosides or aglycones have stimulated the search for the vehicles that would provide their efficient delivery to the systemic circulation. Conjugation of polyphenols with cationic amphiphilic peptides yields compounds with a strong antioxidant activity and ability to pass through biological barriers. Due to a broad range of biological activities characteristic of polyphenols and peptides, their conjugates can be used in the antioxidant therapy, including the treatment of viral, oncological, and neurodegenerative diseases. In this work, we synthesized linear and dendrimeric cationic amphiphilic peptides that were then conjugated with gallic acid (GA). GA is a non-toxic natural phenolic acid and an important functional element of many flavonoids with a high antioxidant activity. The obtained GA-peptide conjugates showed the antioxidant (antiradical) activity that exceeded 2-3 times the antioxidant activity of ascorbic acid. GA attachment had no effect on the toxicity and hemolytic activity of the peptides. GA-modified peptides stimulated the transmembrane transfer of the pGL3 plasmid encoding luciferase reporter gene, although GA attachment at the N-terminus of peptides reduced their transfection activity. Several synthesized conjugates demonstrated the antibacterial activity in the model of Escherichia coli Dh5α growth inhibition.

Exploring antioxidant potential in two basidiomycetous mushrooms using high-performance thin-layer chromatography–DPPH–videodensitometry

The antioxidant activity of the methanol extracts of fruiting bodies of two basidiomycetous mushroom species (Cyclocybe cylindracea and Leccinum duriusculum) was evaluated by high-performance thin-layer chromatography (HPTLC) combined with 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and videodensitometry. The HPTLC separation was achieved on a silica gel layer with acetonitrile–water–acetic acid (75:25:3, V/V). The results were compared with those obtained by the conventional microplate-based DPPH assay. The two methods provided similar results showing that the extract of the C. cylindracea had higher total antioxidant activity than the extract of the L. duriusculum, and the antioxidant activities of both extracts were much weaker than the antioxidant activities of ascorbic acid or gallic acid. Mushroom components in one zone of L. duriusculum extract and three zones of C. cylindracea extract assigned using HPTLC–DPPH–videodensitometry were mainly responsible for the antioxidant activity. Based on a previous study the β-carboline alkaloid C1-S diastereomer of brunnein B in C. cylindracea at hRF 49 contributed to the antioxidant effect the most, which corresponded to 52.0 ± 3.1 ng of ascorbic acid equivalent and 51.7 ± 3.7 ng of gallic acid equivalent.

Metrological Characteristics of the Potentiometric Assay Developed for Determining the Antioxidant Activity of Ascorbic Acid

The potentiometric assay for determining the antioxidant activity of ascorbic acid has been developed and validated according to the following parameters: specificity, linearity, accuracy, repeatability, intermediate precision. The linearity was in the concentration range of 0.002 – 0.02 mol L–1 (r2 = 0.9993). The percentage of recovery was found to be in the range from 95.38 to 105.00 %. The values of %RSD for repeatability and intermediate precision were 1.86 and 1.95 %, respectively. The method is accurate and reliable, with the relative standard deviation of less than 2 %. It has been proven that the method developed is express, rapid, highly sensitive, accurate and sufficiently reliable.

Comparative Study on Phytochemical Screening and Antioxidant Activity of Aqueous Extract from Various Parts of Bauhinia purpurea

In this study, we conducted a comparative investigation into the phytochemical screening and antioxidant activity of aqueous extracts from various parts of the Bauhinia purpurea plant, including leaf, flower, stem bark, and root. The qualitative analysis was performed to screen the phytochemical content of each extract, followed by quantitative analysis to determine the total phenolic and total flavonoid contents. Our findings revealed that different parts of the B. purpureaplant yielded distinct natural products upon extraction. Both the leaf and flower extracts contained alkaloids, flavonoids, saponins, carbohydrates, polyphenols, and phenolics. On the other hand, the aqueous extracts of the stem barks and rootparts of B. purpurea only contained alkaloids, flavonoids, and phenolics. Consistent with the phytochemical assay, the flower extract exhibited the highest total phenolic content (40.14 ± 0.65 µg/mL GAE) and the highest flavonoid content (387.57 ± 0.63 µg/mL CE) compared to the other parts. Consequently, the flower extract displayed the highest antioxidant activity (51.76 ± 0.32%) with DPPH radical assay, closely approaching the antioxidant activity of ascorbic acid (70.54 ± 0.51%), which served as the positive control. This significant finding highlights the potential of the B. purpurea flower as a potent source of antioxidant agents for future applications.

Antioxidant and anti-α-glucosidase activities of biotransformable dragon’s blood via predicted data mining approach

Bacillus megaterium tyrosinase (BmTYR) has been proven an applicable biocatalyst in the ortho-hydroxylation of flavonoids, which usually possess higher antioxidant activity than their precursors. With a predicted data mining approach (PDMA), putative novel bioactive flavonoids from known precursors may be good candidates for biotransformation by BmTYR. Two flavonoid precursors (loureirin A and loureirin B) were confirmed via this approach, which are the commercial constituents of the Chinese medicine dragon’s blood. These two flavonoids were then biotransformed by BmTYR for validation. The results found two novel flavonoids (3′-hydroxyloureirin A and 3′-hydroxyloureirin B), which gained 2.5 and 1.6 times of the antioxidant activity of ascorbic acid, respectively. In addition, all four flavonoids—loureirin A, loureirin B, and the two 3′-hydroxyl derivatives—possessed 4–22 times the anti-α-glucosidase activity of acarbose, a clinical anti-diabetes drug. A further kinetic analysis revealed that the inhibition mode of the four α-glucosidase inhibitors was non-competitive, and their kinetic constants (Ki values) were 64.3 ± 2.5 μM, 308.7 ± 10.4 μM, 69.4 ± 2.8 μM, and 325.3 ± 12.6 μM, respectively. The high antioxidant and anti-α-glucosidase activity suggest that the two novel flavonoids have potential future applications in pharmacology and biotechnology.

Characterization and Antioxidant Activity of Banana Peels, Pineapple Peels, and Combination Extracts of both Peels as Raw Materials in the Development of Hard Candy

Kepok banana and pineapple are horticultural commodities found in West Kalimantan. The two fruits are generally used as processed foods such as fried bananas and pineapple jam. The use of fruit as food often leaves the peel as a by-product, which can produce waste twice the weight of the food consumed. Meanwhile, waste utilization is an innovation in food processing into functional products which are developed into hard candy. Therefore, this research aims to the specific and non-specific characterization of raw materials for making candy, namely the combination of banana and pineapple peel extract (KP-KN). The characterization is organoleptic tests on the content of ethanol-soluble and water-soluble extracts. The Total phenolic content was determined by the Follin ciocalticeu method with UV/Vis spectrophotometry. Furthermore, antioxidant activity tests with DPPH and FRAP methods using UV/Vis spectrophotometry and ELISA to determine antioxidant activity. The mineral content was observed using the molybdate vandalate method with UV/vis spectrophotometry and ICP-MS, Heavy metal contamination using the ICP-MS tool, and microbial contamination using the plate method. Moreover, the infundation process was carried out on banana and pineapple peels, and the results were evaporated using a food dehydrator to obtain a combination extract. The results showed that the organoleptically KP-KN combination extract had a bitter taste, pineapple smells, 15.57% ash content, ethanol soluble extract content of 55.10%, and 47.99% water-soluble extract. Also, the total phenolic of 6.22 g/Kg, as well as the mineral content of Potassium (K), Calcium (Ca), Iron (Fe), Magnesium (Mg), Zinc (Zn), and Phosphorus (P), which were 47.23 g/Kg, 291.43 mg/Kg, &lt;1x10-6 g/Kg, 2.59x10-3 g/Kg, and 2.38 g/Kg, respectively. Meanwhile, the heavy metal and bacterial contamination test showed that Arsenic (As), Sn, Mercury (Hg), and lead (Pb) were &lt;1x10-6 g/Kg and Cadmium (Cd) was 0.0293. In the microbial contamination test with bacterial components including the ALT test, a value of 4.83 x 103 cfu/g was found, and there was no contamination from E.coli, mold, and yeast bacteria, DPPH and FRAP methods showed antioxidant activity combination extract banana peels and pineapple peels with values of 1390.96±2.83 mg/L and 4542.81±1.10 mg/L compare antioxidant activity of ascorbic acid as standard is 2.13 mg/L and 4.83 mg/L. The test with the KP-KN combined extract can be used as a raw material for making hard candy because it contains minerals needed by the body, meets the safety and quality requirements of traditional medicines, and has antioxidant activity in vitro.

Lantana camara L. essential oil mediated nano-emulsion formulation for biocontrol application: anti-mosquitocidal, anti-microbial and antioxidant assay.

Mosquitoes play an important role in the spread of vector-borne diseases and their management is highly essential. Plant extracts have been explored for their mosquitocidal activity against different types of vectors. The present work aimed to determine the larvicidal and pupicidal activity of Lantana camara L. essential oil-loaded nano-emulsion formulation for the control of pests. The synthesized essential oil-loaded nano-emulsion was subjected to evaluate the antioxidant potential and mosquito larvicidal properties. GC-MS analysis revealed that the essential oil of Lantana camara L. leaf contained 12 bioactive components. Caryophyllene oxide (15.81), n-Hexadecanoic acid (4.22), Davanone (6.49) and beta-Sesquiphellandrene (2.32) are the major compounds identified. The nano-emulsion was effective against A. aegypti immature stage (larvae and pupae) and adult mosquitoes in laboratory conditions. The LC50 was found to be 18.183ppm (I), 23.337ppm (II), 29.731ppm (III), 38.943ppm (IV) instars and 45.295ppm (pupae), respectively. The LD50 and LD90 values for adult mosquitoes were 11.947mg/cm2 and 47.716mg/cm2, respectively. The antioxidant activity of ascorbic acid (55.9%), glutathione (67.7%) and quercetin (48.6%) was recorded, respectively. The level of acetylcholinesterase (0.06mM) and alkaline phosphatase (0.05mM) activity significantly decreased from the control (0.12mM) which revealed the efficacy of essential oil-loaded nano-emulsion to treat larvae. This study suggested that using an essential oil-loaded nano-emulsion formulation effectively controlled the mosquito vectors. It was also evidenced that the use of nano-emulsion has a great role in near future, especially in vector management.

Antioxidant activity and the survival-enhancing effect of ascorbic acid on Limosilactobacillus reuteri KUB-AC5 microencapsulated with lactose by spray drying

To improve cell survival during spray drying and storage, an antioxidant has been exploited as a coencapsulant. In this study, ascorbic acid at various concentrations was used to complement the protective ability of lactose for encapsulation of Limosilactobacillus reuteri KUB-AC5. Ascorbic acid at 24 mg/mL had a negative impact on physicochemical properties of microcapsules. Increasing the ascorbic acid concentration reduced the glass transition temperature determined using differential scanning electron calorimetry and promoted agglomeration observed by scanning electron microscopy. After 2 months of storage at 37 °C, X-ray diffraction studies showed that the treatment with 24 mg/mL ascorbic acid had a 314.40% increase in crystallinity. Malondialdehyde before storage decreased with increasing ascorbic acid concentrations, and the highest and lowest survival was found in the samples prepared with 12 and 24 mg/mL ascorbic acid, respectively. A loss of ascorbic acid along with an increase in the half maximal inhibitory concentration was observed during storage, especially at 37 °C. An increase in malondialdehyde and a decrease in viability were found. After storage, the samples with 12 mg/mL ascorbic acid showed the highest survival. The results demonstrate the antioxidant activity of ascorbic acid by hydrogen atom transfer that promotes cell survival under stress conditions.

A Comparative Study on Phytochemical Screening and Antioxidant Activity of Aqueous Extract from Various Parts of Moringa oleifera

In this work, we reported a comparative study on the phytochemical screening and antioxidant activity of aqueous extract from different parts of Moringa oleifera plant, i.e. leaves, twigs, stem barks, and woods. The phytochemical content of each extract was screened through qualitative analysis and followed by quantitative analysis for the determination of total phenolic content and total flavonoid content. The results showed that different parts of Moringa oleifera plant would give different extracted natural products. Either leaf or twig part of Moringa oleifera contained alkaloids, flavonoids, saponins, carbohydrates, polyphenols, proteins, amino acids, and phenolics. Meanwhile, only flavonoids, carbohydrates, and phenolics were found in the aqueous extract of the wood part of Moringa oleifera. In agreement to the phytochemical assay, the aqueous extract of leaf part of Moringa oleifera gave the highest total phenolic content (684 ± 16.7 µg GAE mL-1) and the highest flavonoid content (514 ± 26.1 µg CE mL-1) than other parts. Consequently, the leaf extract exhibited the highest antioxidant activity (64.6 ± 0.69%) which is close to the antioxidant activity of ascorbic acid (71.7 ± 0.56%) as the positive control. This finding is critical for the utilization of Moringa oleifera leaf part as the most potent source of antioxidant agents in the future.

AN EXPERIMENTAL AND THEORETICAL STUDY OF THE REACTIVITY OF SELECTED CATECHOLAMINES AND THEIR PRECURSORS TOWARDS ASCORBYL RADICAL

Ascorbyl radical is often used as a biomarker of oxidative stress in human organism. It is a product of the antioxidant activity of ascorbic acid and it is not expected to react further with biologically important molecules. For the first time, the reactivity of catecholamines and their precursors was investigated theoretically and experimentally towards ascorbyl radical and the main structural parameters governing activity were analyzed. It was shown that catechol moiety plays an important role, which classifies norepinephrine and 3,4-dihydroxyphenylacetic acid as the most reactive when compared to homovanillic acid, vanillylmandelic acid, and octopamine. DFT methods have been employed to determine the most probable mechanism of the reaction. Based on the change in reaction enthalpy it was concluded that Hydrogen Atom Transfer (HAT) is a preferred mechanism both in water and pentyl ethanoate. The stabilization interactions in ascorbic acid, its anion and radical are carefully analyzed in order to understand the preferability of the mentioned mechanism. The stability of the ascorbyl radical is explained in detail. The results prove that ascorbyl radical is not just a product of antioxidant activity, but also a potentially harmful species in an organism.

Determination of Diffusion Coefficients and Antioxidant Activities of Ascorbic Acid in Guava Juice using Cyclic Voltammetry

Ascorbic acid is the most abundant antioxidant present in guava (Psidiumguajava L.). There had only been few studies concerning the determination of diffusion coefficient and antioxidant activity of ascorbic acid in guava juice using cyclic voltammetry specifically at varying temperatures. Thus, this study on the effect of temperature on diffusion coefficient and antioxidant activity on ascorbic acid found in guava was done using cyclic voltammetry. The temperatures tested were at 15°C, 25°C, 36°C, and 45°C. Electrodes used in the experiment were glassy carbon as the working electrode, platinum wire as the counter electrode, and Ag/AgCl electrode as the reference electrode. The results showed that the peak currents of ascorbic acid in guava juice at 15°C, 25°C, 36°C, and 45°C were -0.5720, -0.5380, -0.5000, and -0.4760 μA, respectively. The diffusion coefficients of the ascorbic acid were obtained using the Randles-Sevcik equation at all given temperatures and the values were 2.1489 x10−5, 2.1711 x10−5, 2.2070 x10−5, and 2.2250 x10−5 cm2/s, respectively. The antioxidant activities, in terms of concentration, at the said temperatures were found to be 0.3374, 0.3212, 0.3015, and 0.2899 mM, respectively. It is concluded that at higher temperature, ascorbic acid in guava juice has a higher diffusion coefficient but lower antioxidant activity. The present results can be used by other researchers doing similar work on fate and transport of the studied system.

Utilization of 5‐Chloro‐2‐(cyanoacetamido)pyridines in the Synthesis of Biologically Active Heterocyclic Hybrids

AbstractA simple synthesis for a series of chloropyridine derivatives incorporating heterocyclic hybrids has been accomplished. The key reaction involving employment of 5‐chloro‐2‐(cyanoacetamido)pyridines 3 in the synthesis of chloropyridinyl‐pyridone, chloropyridinyl‐pyrazole, chloropyridinyl‐thiazole and chloropyridinyl‐thiophene hybrids. The newly synthesized heterocycles were evaluated for their antioxidant and antibacterial activities against Gram‐positive and Gram‐negative bacterial strains. 3‐Amino‐N‐(3,5‐dichloropyridin‐2‐yl)‐1H‐pyrazole‐4‐carboxamide (12 b) was found to be the most potent compound against Escherichia coli and Staphylococcus aureus exhibiting inhibition percent of 92.3 % and 100 %, respectively, when compared to the standard drug ampicillin. Moreover, compound 12 b displayed the most significant antioxidant activity with percent inhibition 87.8 % which is close to the antioxidant activity of ascorbic acid.

Antioxidant Effects of Vitamin C on Biomedical UHMWPE Compounds

The aim of the present study is to evaluate the antioxidant activity of ascorbic acid (Vitamin C) at concentrations of 0.5, 1.0, and 2.0% wt on Biomedical Ultra High Molecular Weight Polyethylene (B‐UHMWPE), using a stable free radical 2,2‐diphenyl‐1‐picryl‐hydrazyl (DPPH). The compounds are prepared by compression molding at 160 °C for 6 min, and pressure of 10 MPa. Infrared spectroscopy indicated a weak interaction between the compound constituents, at 3600, 1800, and 1500 cm−1 bands attributed to Vitamin C. Atomic force microscopy (AFM) revealed that the addition of 2.0% wt. of Vitamin C promoted B‐UHMWPE crystalline particle size decreases and molecular disorder. In the presence of the vitamin, Raman spectroscopy suggested a decrease in the degree of polymer crystallinity which may be attributable to modifications in morphological aspects of the polymer. Vitamin C acted as an antioxidant agent, an important result; an increasing amount of radical is scavenged with the addition of the vitamin to the compounds. Thus, Vitamin C presents potential as an antioxidant for B‐UHMWPE compounds.

Anti-inflammatory, anti-nociceptive and antipyretic activity of young and old leaves of Vernonia amygdalina

BackgroundBoth young and old leaves of Vernonia amygdalina (VA) are traditionally used to treat inflammation, pain and fever. However, the efficacy of young and old leaves for treating these ailments have not been compared till date. AimTo ascertain the effect of young and old leaves of VA in managing inflammation, pain and fever. MethodsBoth quantitative and qualitative phytochemical screening of ethanol extracts of young (EthYL) and old (EthOL) leaves of VA were performed. The anti-inflammatory activity of orally administered EthYL and EthOL (50–200 mg/kg) and Diclofenac (10 mg/kg) were evaluated in carrageenan-induced inflammation model in rats. Antipyretic activity of EthYL, EthOL and Aspirin (25 mg/kg) were assessed in the Baker’s yeast-induced pyrexia model. Anti-allodynic effect of both extracts were evaluated by inserting inflamed paws of rats in cold water. Antinociceptive property of the extracts were assessed using tail withdrawal and formalin-induced nociception test. Histopathological examination of the paws was performed, in addition to formalin test to understand the possible mechanism of action of the extracts. Negative control rats received 2 ml/kg normal saline in all tests. ResultsThe amount of flavonoids, alkaloids, tannins, and phenolics were significantly (p < 0.05) higher in EthOL than EthYL, while saponins were significantly higher (p < 0.05) in EthYL than EthOL. The antioxidant ability and total antioxidant capacity were significantly (p < 0.05) higher in EthYL than EthOL. However, this was significantly (p < 0.05) lower than the anti-oxidant activity of Ascorbic acid. A dose-dependent increase in anti-inflammatory, antipyretic and antinociceptive properties were observed in both EthYL and EthOL, similar to the standard drugs. Mast cell degranulation accompanied by vasodilatation and high leukocytosis were observed in the negative control, but were markedly low in extract treated groups. Both extracts mediated their analgesic effect through opioidergic and nitric oxide pathways with EthYL additionally implicating the muscarinic cholinergic system. ConclusionAlthough both EthYL and EthOL alleviate inflammation, pyrexia and nociception, EthYL of VA was found to be more potent than EthOL.

POTENSI AKTIVITAS ANTIOKSIDAN METABOLIT SEKUNDER DARI BAKTERI ENDOFIT PADA DAUN Moringa oleifera L

[POTENTIAL ANTIOXIDANT ACTIVITY OF SECONDARY METABOLITES FROM ENDOPHYTE BACTERIA ON Moringa oleifera L LEAF] This research aims to know the similarities between secondary compound metabolites produced by endophyte bacterial on host leaves and from Moringa oleifera L (kelor) leaves as well as determine the magnitude of antioxidant activity compounds of secondary metabolites produced by bacterial endophyte. Based on the results of the test compound is secondary metabolite in both samples, for secondary metabolite compounds in the extract of the leaves of M. oleifera L. contains identified steroid compounds, flavonoids, saponins, tannins and phenolic compounds, while for metabolites secondary bacterial endophyte undetectable on the existence of any secondary metabolite compounds.For testing of antioxidants on endophyte bacterial extracts of leaves of M. oleifera L is done using the DPPH method, performed on variations of the concentration of 200, 400, 600, 800, and 1000 ppm with Ascorbic acid as a comparison. The results of the test get an IC50 of M. oleifera L leaf extract at 243.67 ppm, and supernatan extract from endophyte bacterial at 492 ppm. The IC50 values showed antioxidant activity in secondary metabolite compounds derived from extracts of the leaves of M. oleifera L which has an extreme antioxidant category. The amount of antioxidant activity for secondary metabolite compound extracts of bacterial endophyte on leaves of M. oleifera L category is feeble, and to extract the supernatan activity is weak compared to the value of the antioxidant activity of Ascorbic acid.

The Effect of Ultrasound Pre-treatment on the Yield, Chemical Composition and Antioxidant Activity of Essential Oil from Wild Lavandula stoechas L.

In this present work, the aim is to evaluate the effect of different times of ultrasound pretreatment prior to hydrodistillation (US-HD) on the yield, chemical composition and antioxidant activity of essential oils of two wild Lavandula stoechas L. from the North of Algeria. The results indicate that ultrasound treatment engenders a rapid release of essential oils (1.59 %) recovery after only 10 min of sample of Adekar treated by ultrasound and followed by 90 min of hydrodistillation (HD) versus 180 min of hydrodistillation of untreated sample (1.17 %). However, the yields of Keddara sample treated by 45 min versus untreated samples were 0.87 % versus 0.62 %. 94.30 % and 88.26 % of total compounds were identified using chromatographymass spectrometry (GC-MS) in samples of Adekar and Keddara treated by ultrasound versus untreated samples (92.64 % and 88.75 % respectively). A difference in chemical composition between the essential oils of the two harvesting sites and between the extracts obtained by HD and by US-HD was found. The percentage of the most of the major compounds (fenchone, camphor, 1,8-cineole, bornyl-acetate, myrtenyl-acetate and viridiflorol) and other compounds identified is higher in treated L. stoechas L. than untreated L. stoechas L. The study of antioxidant power was carried out by 2, 2 diphenyl-1-picrylhydrazyl (DPPH) method. The results showed that antioxidant power of treated samples is superior to antioxidant power of untreated samples. Antioxidant activity of both samples (treated and untreated) is less effective compared with antioxidant activity of ascorbic acid.

The immunomodulatory potential of Leonurus cardiaca extract in relation to endothelial cells and platelets.

The immunomodulatory activity of Leonurus cardiaca L. polyphenol-rich extract (LCE) was tested invitro on HUVECs to explore its potential therapeutic usefulness in the treatment of inflammatory lesions. The phytochemical composition of LCE, its antioxidant and cytotoxic activity, and the influence of LCE on NO and platelet-activating factor (PAF) secretion by HUVECs and platelet aggregation were all assessed. Total polyphenol contents in LCE reached 137.0 ± 0.8 mg/g, with hydroxycinnamic acid derivatives as the predominant phenolic compounds. LCE expressed antioxidant capacity, which was, however, 13- to 16-fold lower than the antioxidant activity of ascorbic acid. The plant extract was not cytotoxic up to a concentration 4500 µg/ml and did not exhibit proapoptotic activity. LCE significantly increased NO production in HUVECs in a concentration-dependent manner and led to the inhibition of PAF secretion induced by staphylococcal peptidoglycan. The extract used at the concentration of 100 µg/ml significantly reduced platelet aggregation in the presence of arachidonic acid. We provide invitro data demonstrating the immunomodulatory potential of LCE, which may be beneficial in preventing the development of difficult-to-treat inflammatory lesions within chronically infected tissues.