Free Radical Scavenging Activity Assay Research Articles

Preliminary Characterization, Antioxidant and Antiproliferative Properties of Polysaccharide from Caulerpa taxifolia

Macroalgae are abundant sources of bioactive polysaccharides and prospective candidates for effective and non-toxic substances. This study aims to preliminary characterize and determine the in vitro antioxidant activity and cancer cell growth inhibitory activity against human lung adenocarcinoma cell (A549) of the polysaccharide from an invasive green alga, Caulerpa taxifolia. Crude polysaccharide (CP) was extracted from the dried algal sample of C. taxifolia by hot water extraction followed by absolute ethanol precipitation. CP was subjected to preliminary chemical characterization, including protein, carbohydrate, and sulfate content analysis by Kjeldahl titrimetry, acid hydrolysis, gravimetry, and ashing-acid water digestion ion chromatography, respectively. Functional groups present in the CP were determined by Fourier transform infrared spectroscopy (FT-IR). Antioxidant activity was evaluated by 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH) free radical scavenging activity assay. The cancer cell growth inhibitory activity against A549 cells was evaluated by MTT assay. Chemical composition of the CP shows 68.4 % (w/w) carbohydrate, 9.4% (w/w) protein, and 0.74% (w/w) sulfate. FT-IR showed the presence of -OH group, C-H stretch groups, C=O groups, and C-O groups and suggested a pyranose configuration of the sugar structure. MTT assay showed the highest inhibition at 25 μg/mL concentration with 35.50% ± 1.66 SEM with a relative IC50 of 45.44 μg/mL. However, the DPPH assay did not exhibit remarkable free radical scavenging capacity than other studies of polysaccharides with only 18.33% at 1 mg/mL. This exploratory study paves the way to explore the mechanism of action of polysaccharides from marine algae as a possible anticancer treatment.

Formononetin Production by Large-Scale Cell Suspension Cultures of Medicago sativa L.

In this study, calli of Medicago sativa L. cv. Elçi (alfalfa Elçi) were inoculated in cell suspension culture and analyzed for aggregate assay, cell viability test, total phenolic content assay, DPPH free radical scavenging activity and formononetin assay by means of High-Performance Liquid Chromatography (HPLC). Hypocotyl, cotyledon and apical meristem explants were taken from 15-day-old aseptic seedlings and germinated in MS medium. 10 g calli were grown for each explant and then transferred into cell suspension culture. The highest cell viability rate, which was 75%, and the highest DPPH free radical scavenging activity with 51.36% was measured in 1000 mL cell suspension culture, while the highest total phenolic content, i.e. 40.2 mg/g, was quantified in 250 mL cell suspension culture. In accordance with the findings of the study, the production of formononetin was higher in the calli derived from cell suspension cultures than in herb samples of M. sativa. Moreover, in 1000 mL cell suspension culture, 4.99 mg/g of formononetin concentration was quantified, which scored the highest. In large-scale cell suspension cultures of M. sativa, it was possible to increase the production of formononetin production. Hence, due to its medicinal significance, a method has been tested to obtain higher amounts of this compound.

PHYTOCHEMICAL SCREENING AND ANTIOXIDANT POTENTIAL OF PTEROCARPUS SANTALINUS L.F. PLANT PARTS

Objective: Oxidation is a normal process in many biological metabolisms in living beings, but in this technology era radiation, pollution, irregular life style, and unhealthy diet leads to excessive oxidation resulting in imbalance between antioxidants and free radicals in body called oxidative stress, which may result in cardiac problems, diabetes, and carcinogenic diseases. Therefore, exploration of natural antioxidants in flora and fauna is becoming important. In this motive a phytochemical study was taken up on various parts of Pterocarpus santalinus L.f. plant belonging to Leguminosae family to check the presence of antioxidant activity (AA).
 Methods: The leaves, flowers, fruits, and roots of this plant were extracted with six different organic solvents from polar to non-polar. To estimate the AA of these extracts, four types of antioxidant tests were done on them, namely, α, α – Diphenyl – β – Picryl - Hydrazyl free radical scavenging activity (DPPH RSA) assay, relative reducing power (RRP) assay, Ferric thiocyanate (FTC) assay, and β - carotene bleaching assay with Butylated Hydroxy Toluene (BHT) as synthetic standard.
 Results: In extraction, Me extracts showed highest yields. Qualitative phytochemical screening has revealed many bioactive components in the Me and Et extracts of plant parts majorly. In DPPH RSA assay, Me extracts of leaves showed RSA activity almost equal to reference standard. In RRP assay, Me floral extracts showed AA higher than standard. FTC and β – Carotene assays showed that Me sample extracts possess good AA than BHT. In FTC assay, lower absorption values specify high AA, whereas in β – Carotene assay, high absorption values indicate high AA of the sample extracts.
 Conclusion: Among six solvents methanol showed highest extraction efficiency and also revealed highest number of phytochemicals in its extracts. These four AA assays revealed that the methanol extracts of all plant parts, that is., leaves, roots, fruits, and flowers possess better AA compared other solvent extracts.

English

The present study was conducted to evaluate the in vitro antioxidant activity of Ficus carica, commonly known as fig. Methanol and ethanol extracts of F. carica leaves were subjected to 2, 2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging activity assay where ascorbic acid being positive control had an IC50 value of 3.98±0.26 while methanol and ethanol fractions showed an IC50 of 101.76±1.12 and 93.12±1.17 respectively exhibiting their high antioxidant potential. DPPH assay was also performed on high performance liquid chromatography (HPLC) elutions. Most active antioxidant components in ethanol extract were eluted between 17–18 min, and those in methanol were eluted over 14–15 min and upon ultra-high performance liquid chromatography-mass spectrometery (Orbitrap Liquid Chromatography-Mass Spectrometry) were identified to be 13-Docosenamide, (Z)- for ethanol and ficusin for methanol fraction. Thus, it is concluded that these two components are most probable determinants of antioxidant potential of F. carica leaf extracts. © 2021 Friends Science Publishers

In vitro antioxidant, antibacterial, and antihyperlipidemic potential of ethanolic Avicennia marina leaves extract supported by metabolic profiling

This study aimed to examine the impact of ethanolic Avicennia marina (A. marina) leaves extract against seven pathogenic bacteria and the protective effect of this plant against hyperlipidemia caused by dexamethasone (DEX)-treated rats. Forty-eight male rats weighing between 150 and 200 g were randomly selected into six groups containing eight rats in each group. Moreover, in vitro antioxidant DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free radical scavenging activity, FRAP (ferric reducing antioxidant power), and ABTS assay were also analyzed for leaf extract. Results showed that the IC50 values were observed as 193.9 ± 1.03 μg/mL, 340.29 ± 8.16 μM TE/mg, and 326.8 ± 6.14 μM TE/mg for DPPH, FRAP, and ABTS radical scavenging activities, respectively. A. marina leaves ethanolic extract exhibited higher activity against Candida albicans and Bacillus subtilis, moderate activity against Salmonella typhimurium, and Vibrio damsel. The administration of DEX resulted in significant (P < 0.05) increase in the levels of MDA concentration, TG, TC, LDL, LDH, and glucose but decreased significantly in HDL. Treatment with A. marina extract positively reversed the distorted lipid profile and peroxidation and improved MDA, GSH, NO, and SOD activities in DEX-administered rats. Histological investigation of liver tissue sections showed that the treatment with A. marina leaves extract moderate the fatty change caused by DEX. It is concluded that A. marina leaves extract improved the hypolipidemic property of DEX administration in comparison with standard treatment with atorvastatin.

MELICA UNIFLORA YAPRAKLARININ ETANOLİK ÖZÜTLERİNİN IN VITRO BİYOLOJİK AKTİVİTESİNİN DEĞERLENDİRİLMESİ

Melica uniflora is part of the omnivore and herbivore animal diets and there is not enough study about this plant. The aim of the study is to provide the antimicrobial and antioxidant potential of ethanol extract of M. uniflora leaves. Total phenolic and flavonoid contents and antioxidant potential based on different methods and antimicrobial activity of M. uniflora leaves ethanol extract were examined. Disk diffusion method against to eight bacteria strains, the Folin-Ciocalteu method, DPPH free radical scavenging activity and ferric reducing antioxidant power assays were used. Mean diameters of inhibition zones were found in the range of 14.93 mm to 26.32 mm. The total phenolic content of ethanol extract of M. uniflora leaves was determined as 0.466 mg GAE/g. Total antioxidant activity value of the extract was calculated 4.54 mg AAE/g. IC50 value was calculated 18.798 mg/mL for DPPH free radical scavenging activity. The FRAP value indicated that the reducing power of 1 gram of sample was equivalent to 3.33 µmol of trolox. The flavonoid content of the extract was calculated as 4.44 mgQE/g. According to the obtained results, the analyzed M. uniflora leaves ethanol extracts demonstrated antioxidant and antimicrobial activity level can be considered effective.

Antioxidant activity and solar protection factor of two Vismia species colleted from Venezuelan Andean

Long lasting exposure to UVA and UVB radiation might lead to premature aging and the appearance of skin cancer. The use of photoprotectors that contain oxygenated aromatic chemical compounds obtained from natural sources has been established. Species of Vismia genus (Hypericaceae), distributed mainly in the tropical zone of Central and South America, has been used in traditional medicine to alleviate several ailments. Present investigation aims to evaluate the free radical scavenging capacity, total phenolic, flavonoids content, solar protect factor and the qualitative phytochemical screening of methanol extracts obtained from Vismia baccifera (VB) and Vismia macrophylla (VM). Free radical scavenging activity, total phenolic and total flavonoid content assays were performed in order to determine antioxidant activity on the extracts under investigation. Methanol extracts of VB and VM showed by means of phytochemical screening the presence of polyoxygenated compounds like anthraquinones, xanthones, anthrones and flavonoids. The antioxidant activity study carried out with DPPH and total phenol content assays showed similar values for both species, IC50 5.90 µg mL-1 (VB) and 5.65 µg mL-1 (VM); 375.32 and 381.23 mg Eq ÁG/g Ext, respectively. However, VB showed a higher amount of flavonoids with 267.07 mg Eq Q/g Ext. On the other hand, the In Vitro study to determine the solar protection factor displayed values of 25.3 for VB and 20.7 for VM, being these considered as medium protection capacity according to FDA and COLIPA data. Results obtained are considered as contribution to Vismia genus activity investigation.

Chemical Composition and Antioxidant Activities of Leaf and Flower Essential Oils of Origanum onites L. Growing in Mount Ida-Turkey

The chemical composition of leaf and flower essential oils of Origanum onites L. were analyzed using Thermo Scientific TSQ GC-MS/MS. Also, antioxidant activities of the leaf and flower essential oils were investigated by using DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging activity and β-carotene linoleic acid assays. BHA (Butylated hydroxyanisole) and BHT (Butylated hydroxytoluene) were used as standards. The essential oil yields of O. onites were 1.75 % for leaves, and 4.25 % for flowers. A total of twenty-three compounds representing 99.9 % of leaf oil and twenty-four compounds constituted 99.6 % of the flower oil were determined. Oxygenated monoterpenes were detected at a high percentage (69.2 %) in leaf essential oil and carvacrol (64.9 %) was determined as the main compound. Also, flower essential oil was dominated by sesquiterpene hydrocarbons (73.5 %) and α-cubebene (36.4 %) was determined as major compound. For leaf oil, a high antioxidant capacity was determined, primarily due to carvacrol and p-cymene.

Bioactivity evaluation of commercial root samples of Hemidesmus indicus (L.) R.Br.

Four commercial root samples (CS1, CS2, CS3 and CS4) of Hemidesmus indicus alongside an authentic sample (HI) were evaluated following antibacterial potential, cytototoxicity and DPPH free radical scavenging activity assay. The inhibition zones produced by commercial samples ranged between 9.5 to 13.5 mm against the tested bacteria in antibacterial sensitivity test. HI produced highest inhibition zone recorded as 20.63 mm against Staphylococcus aureus followed by 17.4 mm against Bacillus subtilis at 150 μg/ml concentration. HI also showed highest cytotoxicity with LC50 value of 1.726 mg/ml, 4.754 mg/ml and 13.247 mg/ml after 6 hours, 12 hours and 24 hours respectively in brine shrimp lethality assay. Sample CS1 and CS2 showed less cytotoxicity compared to CS3 and CS4. Depending on the concentration of extracts, the DPPH free radical scavenging activities of commercial samples were in close proximity with HI. The total phenolic content in HI was 54.52 mg/ml while in four commercial sample, it ranged between 52.28 to 75.37 mg/ml gallic acid equivalent (GAE) per 100 mg extract.&#x0D; Jahangirnagar University J. Biol. Sci. 8(2): 61-69, 2019 (December)

Aktywność przeciwutleniająca i przeciwbakteryjna miodu, propolisu oraz pyłku kwiatowego

Introduction. Honey, propolis and pollen belong to bee products that have beneficial biological properties. These products exhibit e.g. antibacterial, antifungal and antioxidant properties. Due to biological activity and natural origin, bee products are used, e.g. in the food industry, cosmetology and pharmacy. Aim. The aim of the study was to compare the antioxidant and antibacterial activity of honey, propolis and pollen from an apiary located in Wielkopolska Province. Material and methods. Honey, propolis and pollen used in this study came from the same apiary located in Wielkopolska Province. The antioxidant potential of bee products was evaluated applying DPPH· free radical scavenging activity assay. The antimicrobial activity of the tested bee products was determined by the point-diffusion method against 13 strains of pathogenic and potentially pathogenic bacteria. In addition, the total content of phenolic compounds in honey, propolis and pollen was determined by the colorimetric method. Results. Propolis exhibited higher antioxidant activity, in comparison to honey and pollen. The antiradical activity of propolis was equal to 80% approx. activity of Trolox, the standard antioxidant. Among tested bee products, propolis was characterized by the highest total phenols content. In addition, honey, propolis and pollen showed antagonistic activity against tested bacterial strains. Conclusions. The obtained results indicate that among the tested bee products of native origin, i.e. honey, propolis and pollen, propolis characterized by the highest antioxidant activity and the total content of phenolic compounds. In addition, all bee products showed bactericidal activity against the tested bacterial strains.

Seasonal variation of fatty acid composition, tocopherol content and antioxidant activity of lipid extracts from Centaurea sp.

The changes in fatty acid (FA) composition, and total tocopherol content (TTC) of leaves, roots and roots' bark of Cenaurea sp. grown on the Algerian coast were studied. Moreover, the change within the same season in antioxidant activity of lipid fractions was also measured using the DPPH free radical scavenging activity assay. Results showed quantitative and qualitative changes of the contents of saturated, monounsaturated, polyunsaturated fatty acids and TTC from January until June with different patterns for the different plant parts. The highest TTC were obtained for both roots and roots' bark, and changed differently with the month of collection. The antioxidant IC50 values also showed different pattern changes during the season for roots and roots' bark. Cluster analysis using Agglomerative Hierarchical Clustering showed differences in FA amounts for C18:2 and C18:3 between roots’ bark and both roots and leaves parts, which were totally independent of the month of collection.

Evaluation of Antioxidant Activity and Inhibition of Tyrosinase Activity of Raphanus sativus var. caudatus Alef Extract

This study was aimed to determine antioxidant and tyrosinase inhibition effects of the pod of Raphanus sativus L. var. caudatus Alef extract. The compounds consisted in the extracts were identified by HPLC from standard peak comparison. Pod was extracted by using 2 different solvents-dichloromethane (DCM) and water. The antioxidant activity was evaluated based on free radical scavenging (DPPH) activity and ferric reducing ability (FRAP) assay. The lightening effect was determined from the inhibition of mushroom tyrosinase in vitro. The results showed that DCM extract contained sulforaphene, protocatechuic acid, p-hydroxybenzoic acid, caffeic acid, and ferulic acid. The aqueous extract contained sulforaphene, protocatechuic acid, p-hydroxybenzoic acid, caffeic acid, vanillic acid, and p-coumaric acid. The DPPH· scavenging effect expressed as the IC50 values for DCM and aqueous extracts were 883.38 ± 22.9 and 1,160.49 ± 22.30 µg/mL, respectively. The reducing power of aqueous extract (218.27 ± 0.010 µM FeSO4 equivalent) was greater than DCM extract (166.34 ± 0.018 µM FeSO4 equivalent) at the same concentration (2,000 µg/mL). However, both extracts showed lesser antioxidant activity than gallic acid, a positive control. DCM extract showed higher tyrosinase inhibitory effect than aqueous extract but lesser than kojic acid, a positive control. Both extracts at 2,000 µg/mL concentration exerted 42 and 19 % tyrosinase inhibition, respectively. In conclusion, the extraction solvent yielded different chemical constituents and thus the activities. The DCM extract exerted greater antioxidant activity and tyrosinase inhibition activity than the aqueous extract. The extract fractionation is required to get higher yields of bioactive compounds prior to further study and for cosmetics product development.

Effects of Mass Selection on Husk and Cob Color in Five Purple Field Corn Populations Segregating for Purple Husks

Improvement of anthocyanin levels in husks and cobs of field corn may add economic value to corn coproducts in commercial production. This study aimed to evaluate the response to four cycles of modified mass selection (MMS) for yield, agronomic traits, total anthocyanin yield (TAY), total anthocyanin content (TAC), total phenolic content (TPC) and antioxidant activity determined by 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity assay (DPPH) and trolox equivalent antioxidant capacity assay (TEAC) in corn husk and cob of five purple field corn populations. The improved populations and check varieties were evaluated at two locations for two seasons in 2017/2018. Selection cycle contributed to a large portion of the total variations for TAC, TPC, DPPH and TEAC in corn husk and cob. All tested populations showed progress for days to anthesis, TAY, TAC, TPC, DPPH and TEAC across four cycles of selection. Lack of significant correlation between agronomic traits and anthocyanin concentrations suggested the independent segregation of these traits. MMS was successfully used to develop field corn populations with improved anthocyanin, antioxidant activities and early flowering without significant yield loss. The populations with the highest selection gains for anthocyanin in husk and cob were identified. Visual selection for dark purple husks and cobs boosted anthocyanin levels and antioxidant activity in selected populations.

Synthesis, characterization and SAR studies of bis(imino)pyridines as antioxidants, acetylcholinesterase inhibitors and antimicrobial agents

In this study we synthesized a series of sixteen bis(imino)pyridines (BIPs) starting from 2,6-diaminopyridine and various aromatic aldehydes, and evaluated their antioxidant, antibacterial, antifungal and acetylcholinesterase (AChE) inhibitory activity. The chemical structures were elucidated by FTIR, elemental analysis, ESR and HRMS. 1H and 13C NMR spectra couldn’t be acquired due to the formation of stable, carbon-centered radical cations in a solution, as confirmed by ESR spectroscopy and DFT calculations. The in vitro antioxidant potency was evaluated using four assays: free radical scavenging activity (DPPH and ABTS), reducing power and total antioxidant capacity assay. BIPs demonstrated excellent antioxidant properties, and two derivatives proved to be more potent than reference antioxidants (ascorbic acid and Trolox) in all assays. DFT calculations on ωB97XD/6-311++g(d,p) level of theory provided valuable insights into the radical scavenging mechanism of BIPs. For hydroxyl-substituted BIPs, hydrogen atom transfer (HAT) is a predominant mechanism, while the single electron transfer coupled with proton transfer (SET-PT) governs the antioxidant activity of other derivatives. Intramolecular hydrogen bonding (IHB) plays an important role in the mechanism of antioxidant activity as revealed by noncovalent interaction analysis and rotational barrier calculations. The spin density of radical cations is localized on carbon atoms of a pyridine ring, which corroborates with g-factors and multiplicity obtained from ESR analysis. The most potent BIP exhibited moderate inhibitory activity toward AChE (IC50 = 20 ± 4 μM), while molecular docking suggested binding at the peripheral anionic site of AChE with the MMFF94 binding enthalpy of −43.4 kcal/mol. Moderate in vitro antimicrobial activity of BIPs have been determined against several pathogenic bacterial strains: Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus and clinical isolate of methicillin resistant S. aureus (MRSA). The antifungal activity of BIPs toward Candida albicans was also confirmed. The similarity ensemble approach combined with molecular docking suggested leucyl aminopeptidase as the probable antimicrobial target for the three most potent BIP derivatives.

Aktywność biologiczna roślinnych produktów pszczelich pochodzących z Gór Sowich

Introduction. Herbal bee products, including honey, propolis and pollen, are wide applied in various branches of industry due to their natural origin and biological activities. Bee products exhibit e.g. antioxidant, antibacterial and antifungal activity. In addition, honey, propolis and pollen characterize diverse and complex chemical composition. Aim. The aim of the study was to determine antioxidant and antibacterial activity of honey, propolis and pollen from the Sowie Mountains. Material and methods. In the study, honey, propolis and pollen collected from an apiary located in the Sowie Mountains were used. The tested bee products were extracted with ethanol, and the obtained extracts from bee products were used to determine their antioxidant and antibacterial activity. The antioxidant potential of bee products were evaluated applying DPPH· free radical scavenging activity assay. The antimicrobial activity of the tested bee products was determined by the point-diffusion method against 13 strains of pathogenic and potentially pathogenic bacteria. In addition, the total content of phenolic compounds in the tested bee products was determined by the Folin-Ciocalteu method. Results. Among the tested bee products, propolis exhibited the highest antioxidant activity. The antiradical activity of propolis was equal to 96% approx. activity of Trolox, the standard antioxidant used in this study. Propolis had the highest total phenol content. All bee products showed antagonistic activity against all tested bacterial strains, however, propolis was characterized by the highest antibacterial activity. Conclusions. The obtained results indicate that among the tested bee products (honey, propolis and pollen), the highest antioxidant and antibacterial activity showed propolis. The high biological activity of propolis is associated with the high content of phenolic compounds.

English

In Asian subcontinent, Caryota urens L. plant is well known. Its leaf has antioxidant and antimicrobial properties. The work aims to analyze the composition of the plant&rsquo;s fruit extract and its aqueous and organic soluble fractions for its cytotoxic, thrombolytic, antioxidant, membrane stabilizing and antimicrobial properties. 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity assay, phosphomolybdenum total antioxidant assay and total phenolic content were used to evaluate the antioxidant activity. Brine shrimp lethality bioassay was used to determine the cytotoxic property. In thrombolytic activity assay, streptokinase was the standard. The samples were exposed to membrane stabilizing activity assay under heat and hypotonic solution-induced conditions. The samples&rsquo; antimicrobial potential was evaluated with Disc diffusion assay. The crude methanol extract showed&nbsp;&nbsp; the highest free radical scavenging activity (IC50 = 62.74&plusmn;0.16 &mu;g/mL) that can correlate with its total phenolic content of 106.88&plusmn;0.19 mg of GAE / g of sample. The crude methanol extract showed the highest cytotoxic potential (LC50 = 0.59&plusmn;0.34 &mu;g/mL). The carbon tetrachloride soluble materials revealed 20.48&plusmn;0.44% of clot lysis in the assay for thrombolytic activity. The crude methanol extract prevented haemolysis of human erythrocytes in hypotonic solution-induced condition by 64.17&plusmn;0.26%. Key words: Caryota urens L., free radical scavenging activity, brine shrimp lethality, thrombolysis, membrane stabilization. &nbsp

GC-MS Analysis of Phytochemical Composition, Antibacterial and Antioxidant Properties of Ethanolic Extract of Detarium microcarpum (OFOR)

The increasing use of Detarium microcarpum as food and in treatment of different ailment and the understudy of its bioactive and chemical composition resulted to this work on GCMS studies of phytochemical composition, antibiotic and antioxidant properties of ethanolic extract of ofor (Detarium microcarpum). Ethanol extract of seed of Detarium microcarpum showed the presence of the various phytochemicals; saponin, flavonoids, steroid, proteins, anthraquinnones and alkaloids. The following phytochemicals were absence from the sample; tannins, terpenoids, cardiac glycoside, phulobactanins, phenolic compounds and reducing sugars. GCMS analysis showed the presence of 9, 12-Octadecadienoic acid (Z,Z)- as a main compound in the extraction. The aqueous extraction showed 28.59% and the least compound showed methyl tetradecanoate and the aqueous extraction is 1.13%. The activities of 10mg/2ml of the seed extract on selected bacterial organisms with Minimium Inhibition Concentration (MIC) of Eseterichia coli (10μl), Pseudomonas aeruginosa (100μl) Staphylococcus aureus (50μl) and Bacillus suptili (20μl) justified the use of the plant seeds for various treatments by local traditional practitioners. Antioxidant activities of Detarium microcarpum seed determined by the free radical scavenging activity (DPPH) assay method indicated a steady increase in the scavenging activity of free radicals in all extracts from 322 to 1011μg/mL. The usage of this ornamental plant should be promoted as an alternative for synthetic chemicals as it is easily available, grown and maintained, accessible and affordable. The high antioxidant potential, free radical scavenging activity and anti-oxidative enzymes of Detarium microcarpum should be utilized to develop new drug candidates for antioxidant therapy

Comparison of Total Phenolic Contents and Antioxidant Activities of Centella asiatica Extracts Obtained by Three Extraction Techniques

Through different extraction techniques, the potential of Centella asiatica as a natural source of antioxidant was investigated. The C. asiatica aqueous extracts were obtained via infusion, decoction and ultrasonic-assisted extraction (UAE) techniques. The effects of different extraction techniques were studied on the extraction yield, total phenolic contents and antioxidant activity. The total phenolic contents of the extracts and antioxidant activity were examined using the Folin-Ciocalteu’s reagent and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity assay, respectively. Results indicated that the UAE exhibited the highest extraction yield, highest total phenolic contents, as well as highest antioxidant activity. The yield of the extracts increased in the order of infusion &lt; decoction &lt; UAE which were 18.2 %, 23.6% and 25.4 %, respectively. All extraction techniques had a significant effect (p &lt;0.05) on the total phenolic contents and antioxidant activity of C. asiatica extracts. The total phenolic contents was ranged from 3.42 ± 0.030 to 8.32 ± 0.105 mg GAE/g dry extract while the antioxidant activity was in the range of 75 to 86 %. This study confirms that C. asiatica has the potential to be a good resource for the future development of natural antioxidant. In addition, extraction via UAE can be an ideal technique to obtain phytochemical-rich extracts from medicinal plants.

Edible films based on chitosan-flaxseed mucilage: in vitro antimicrobial and antioxidant properties and their application on survival of food-borne pathogenic bacteria in raw minced trout fillets

Various natural oils/extracts and their constituents incorporated into biopolymer-based edible films as a promising technology with the knowledge that these compounds have been able to reduce microbial growth and chemical changes of packed foodstuffs. The objective of this study was to evaluate the effect of incorporation of Ziziphora clinopodioides essential oil (ZEO; 0, 0.25 and 0.5%) and sesame oil (SO; 0, 0.5 and 0.75%) into chitosan-flaxseed mucilage (CH-FM) film against Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus and Escherichia coli O157:H7 in vitro condition and raw minced trout fillets during refrigerated condition. The in vitro antibacterial and antioxidant properties of CH-FM films were evaluated using agar disk diffusion method and free radical scavenging activity assay, respectively. The most important constituents of ZEO were found to be carvacrol (65.22%), thymol (19.51%), ɣ-terpinene (4.63%) and p-cymene (4.86%). The lowest and highest antimicrobial effect against S. aureus, L. monocytogenes, E. coli O157:H7 and S. typhimurium were found for CH-FM films enriched with SO 0.5% (0.98-1.24 mm) and ZEO 0.5% + SO 0.75% (5.01-6.25 mm), respectively. The antioxidant property of CH-FM based films were found to be ranged 5.45% ± 0.04-37% ± 0.45. In treated trout fillets, the counts of L. monocytogenes, S. aureus, E. coli O157:H7 and S. typhimurium were 1.54-4.18, 0.34-3.35, 0.29-1.45 and 0.19-1.27 log CFU/g significantly lower than control groups after two weeks of refrigerated storage, respectively. The designated films had good antibacterial effect against some food borne pathogenic bacteria including L. monocytogenes, S. aureus, S. typhimurium and E. coli O157:H7 in raw rainbow trout fillets.

Antioxidant Activity of Avicennia alba Blume, (1826) Family Avicenniaceae, Leaf Extracts Using DPPH Assay

The antioxidant activity of Avicennia alba Blume, (1826) leaf extract was determined using 1,1-Diphenyl-2-picrylhydrazyl (DPPH) Free Radical Scavenging Activity Assay. Petroleum ether and 95 % ethanol were used as solvents in two separate macerations. Only the ethanolfree extract (TSB) exhibited antioxidant activity; it showed a color change from purple to light yellow similar to positive control (ascorbic acid solution) and a decrease in absorbance relative to negative control (95% ethanol). The results of the DPPH free radical scavenging activity assay was subjected to statistical analysis using one way ANOVA then post hoc analysis results of TSB showed no significant difference vs positive control, a percentage antioxidant activity of 68.24% ± 12.23 and 76.43% ± 9.22 respectively. The ethanol-free extract (TSB) underwent phytochemical screening by test tube method where it revealed the presence of saponins, tannins, flavonoids, and glycosides. It was then subjected to column chromatography for partial purification of its chemical compounds; fractions from the eulates were collected and were pooled according to their TLC profile specifically Rf values. The fractions that showed significant spots under UV light were fractions 1 and 2; and fractions 4 and 5. These two sets of fractions were tested to DPPH free radical scavenging assay. Both fractions showed similar color change as the positive control and a decrease in absorbance relative to the negative control. Fractions 1&amp;2 showed 69.97% ± 2.439 percentage antioxidant activity which had no significant difference to the positive control with the highest antioxidant activity of 87.88% ± 3.357 .The p-value (&lt;0.01) obtained manifested that there was significant difference between the test solutions with their antioxidant activity. After DPPH assay, the most active fractions 1 &amp; 2, were subjected to FT-IR and GC-MS. Infrared spectrum showed the presence of aliphatic C-H bonds, C=O bond, and –OH bonds while the GC-MS analysis revealed five compounds which were based on the molecular ion showed at m/z = 537.4. The functional groups present in the compounds from FT-IR and GC-MS analyses and the secondary metabolites present in phytochemical screening seemed to be responsible for the antioxidant activity of Avicennia alba leaf extracts.