Determined Using The 1,1-diphenyl-2-picrylhydrazyl Research Articles

In silico molecular docking and comparative in-vitro analysis of ethyl 3, 4, 5-trihydroxybenzoate and its derivative isolated from Hippophae rhamnoides leaves as free radical scavenger and anti-inflammatory compound

Background: Excessive production of reactive oxygen species (ROS) associated with oxidative stress induce tissue injury that might trigger the inflammatory process. Superoxide dismutase (SOD) and cyclooxygenase 2 (COX-2) play a significant role in the inflammation prompt after the overproduction of ROS. Polyphenols compound play an important role in alleviating problem associated with oxidative stress. Hippophae rhamnoides leaves extract contain major bioactive polyphenol compound Ethyl 3,4,5-trihydroxybenzoate (gallic acid ethyl ester [GAE]), Gallic acid (GA) and need to be investigate for its anti-oxidant and anti-inflammatory properties. Objective: The objective of this study is to determine the antioxidant and anti-inflammatory potential of GAE and GA derivatives isolated from H. rhamnoides leaves, in vitro and in silico approach target on COX-2 and SOD receptor. Materials and Methods: The isolated compounds GAE, GA, and derivatives 4-O methyl gallic acid (4-OMGA), pyrogallol (PG) were docked using Schrodinger's (LLC, Cambridge, USA) tools. Further in vitro antioxidant activity was determined using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radical anion scavenging activity. The anti-inflammatory activity was evaluated using COX-2 inhibitory assay in lipopolysaccharide-stimulated RAW 264.7 cell line. Results: In silico result showed notable binding affinity of GAE with the SOD and COX-2 receptors followed by GA > PG > 4-OMGA. Experimentally, GAE confirmed promising antioxidant potential (DPPH; half-maximal inhibitory concentration 20.3 ± 2.65), SOD anion at 50 μM as well anti-inflammatory activity by inhibiting the COX-2 activity in RAW 264.7 cell line. Conclusion: The result demonstrated the potential biological activities of GAE, GA, and derivatives. In silico finding may act as precious tools to further unlock these potential therapeutic agents against oxidative stress.

Formulation of Antioxidant Gel from Black Mulberry Fruit Extract (Morus nigra L.).

Background:Ultraviolet (UV) radiation from the sun that is composed of UVA and UVB can cause premature aging when exposed to the skin. Black mulberry fruit (Morus nigra L.) contains anthocyanins as antioxidants that can be protective against UV exposure. The aim of this research was to produce gel formulation from the extract of black mulberry as an antioxidant and sunscreen.Materials and Methods:This research started with the maceration process using 96% ethanol solvent. Later, antioxidant activity of the extract was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and compared with vitamin C. Furthermore, the extracts were formulated into gel with variations of hydroxypropyl methylcellulose, sodium carboxymethyl cellulose, Carbopol 934, and extract concentrations. The products were then physically evaluated, including organoleptic evaluation, homogeneity, pH, viscosity, and dispersion, as well as the hedonic test, irritation test, and antioxidant activity test.Results:The results showed that black mulberry extract had antioxidant activity with the half maximal inhibitory concentration (IC50) value of 146.73ppm and its antioxidant strength was 39.6 times lower than that of vitamin C. The formulation with best physical evaluation results was given by formula 4 (Carbopol 934, 1.5%) with extract concentration 0.61%. This formula showed antioxidant activity with an IC50 value of 104.659ppm. Furthermore, on the basis of hedonic test and irritation test, this formula was the most popular and was categorized as a safe topical gel.Conclusion:The gel of black mulberry extract had antioxidant activity and was categorized as a safe topical gel.

Antioxidant activity of different species and varieties of turmeric (Curcuma spp): Isolation of active compounds

There are >80 species of turmeric (Curcuma spp.) and some species have multiple varieties, for example, Curcuma longa (C. longa) has 70 varieties. They could be different in their chemical properties and biological activities. Therefore, we compared antioxidant activity, total phenolic and flavonoid content of different species and varieties of turmeric namely C. longa [variety: Ryudai gold (RD) and Okinawa ukon], C. xanthorrhiza, C. aromatica, C. amada, and C. zedoaria. The antioxidant activity was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, oxygen radical absorbance capacity (ORAC), reducing power and 2-deoxyribose (2-DR) oxidation assay. Our results suggested that RD contained significantly higher concentrations of total phenolic (157.4 mg gallic acid equivalent/g extract) and flavonoids (1089.5 mg rutin equivalent/g extract). RD also showed significantly higher DPPH radical-scavenging activity (IC50: 26.4 μg/mL), ORAC (14,090 μmol Trolox equivalent/g extract), reducing power absorbance (0.33) and hydroxyl radical scavenging activity (IC50: 7.4 μg/mL). Therefore, RD was chosen for the isolation of antioxidant compounds using silica gel column, Toyopearl HW-40F column, and high-performance liquid chromatography. Structural identification of the compounds was conducted using 1H NMR, 13C NMR, and liquid chromatography-tandem mass spectrometry. The purified antioxidant compounds were bisabolone-9-one (1), 4-methyllene-5-hydroxybisabola-2,10-diene-9-one (2), turmeronol B (3), 5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)-1-hepten-3-one (4), 3-hydroxy-1,7-bis(4-hydroxyphenyl)-6-hepten-1,5-dione (5), cyclobisdemethoxycurcumin (6), bisdemethoxycurcumin (7), demethoxycurcumin (8) and curcumin (9). The IC50 for DPPH radical-scavenging activity were 474, 621, 234, 29, 39, 257, 198, 47 and 18 μM and hydroxyl radical-scavenging activity were 25.1, 24.4, 20.2, 2.1, 5.1, 17.2, 7.2, 3.3 and 1.5 μM for compound 1, 2, 3, 4, 5, 6, 7, 8 and 9, respectively. Our findings suggested that the RD variety of C. longa, developed by the University of the Ryukyus, Okinawa, Japan, is a promising source of natural antioxidants.

Antioxidant, anti-inflammatory, and antiproliferative activity of extracts obtained from Tabebuia Rosea (Bertol.) DC

Background: Tabebuia rosea (Bertol.) DC. is a neotropical tree used in traditional medicine in the Northern coast of Colombia as well as Latin America for infectious diseases treatment. Few studies have evaluated the biological activity of this species. Objective: The objective of this study is to determine the antioxidant, anti-inflammatory, and antiproliferative potential of leaf and inner bark extracts from T. rosea. Materials and Methods: The antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) methods. The anti-inflammatory activity was evaluated in lipopolysaccharide-stimulated murine macrophages. In vitro antiproliferative effect was determined in HepG2, HeLa, MCF-7, and B16F10 cell lines. Results: The highest DPPH radical scavenging activity was observed for T. rosea ethyl acetate leaf extract (IC50of 157.5 ± 2.4 μg/mL). This extract also induced the best antioxidant activity as determined by ORAC (11,112.2 ± 1,255.3 μmol TE/g of extract). Moreover, T. rosea leaf n-hexane, chloroform, and aqueous extracts, in addition to inner bark aqueous extract did inhibit nitric oxide production by over 90%. In addition, inner bark extracts markedly inhibited prostaglandins E2 and tumor necrosis factor alpha (>90%). The best antiproliferative activity was displayed by the inner bark chloroform extract against HepG2 (selectivity index [SI] = 5.50) and B16F10 (SI = 3.18) cell lines. Conclusion: These results demonstrate the potential biological activity of T. rosea extracts. Abbreviations used: DPPH: 2,2-diphenyl-1-picrylhydrazyl; ORAC: Oxygen radical absorbance capacity; LPS: Lipopolysaccharide; NO: Nitric oxide; TNF-a: Tumor Necrosis Factor Alpha; PGE2: Prostaglandin E2; TAC: Total antioxidant content; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide.

Determination of antioxidant activity of surface‐treated PET films coated with rosemary and clove extracts

Commercial PET films were surface treated and subsequently coated with either rosemary (RME) or clove (CE) extracts. Surface treatments involved (1) corona treatment, (2) chemical modification, and (3) plasma treatment. Radical scavenging activity (RSA) of both pure plant extracts and coated film extracts were determined using the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) method. RME‐coated films showed a % RSA of 25.6%, 22.4%, and 24.1% for plasma, chemical modification, and corona treatment, respectively, at an extract concentration of 1402 ppm, respectively, while pure RME showed a %RSA of 16.0%. Respective %RSA values for CE were 25.0% for plasma, 25.2% for chemically modified, and 25.2% for corona‐treated films at 1402 ppm, while pure CE showed a %RSA of 47.6%. Thiobarbituric acid (TBA) test, performed on ground fish muscle wrapped in all types of employed films, showed a remarkable decrease in the degree of fish oxidation ranging between 50.0 and 80.0% after 6 days of storage. Contact angle measurements confirmed that surface chemically modified films had the highest adhesion strength followed by corona and plasma‐treated films. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X‐ray photoelectron spectroscopy (XPS) data also supported contact angle measurements. Finally, the oxygen permeability of surface‐treated films did not differ from untreated films indicating that surface treatment did not affect film barrier properties.

Phytochemical analysis with free radical scavenging, nitric oxide inhibition and antiproliferative activity of Sarcocephalus pobeguinii extracts

BackgroundFree radicals have been implicated in the pathogenesis of diverse metabolic disorders including cancer. Therefore, fighting against free radicals has become an important strategy in the prevention or treatment of such diseases, in addition to direct or indirect anticancer chemotherapy. Sarcocephalus pobeguinii has been used traditionally to treat various diseases in which excess production of free radicals is implicated, warranting investigation of its free radical scavenging, anticancer and anti-inflammatory activity.MethodsIn the present study, extracts from leaves, fruits, roots and bark of Sarcocephalus pobeguinii were evaluated on four human cancer cell lines (MCF-7, HeLa, Caco-2 and A549 cells) and a non-cancerous cell line for their antiproliferative potential. The cells were incubated with the plant extracts for 48 h at 37 °C in a 5% CO2 humidified environment and their cytotoxic effect was determined using the tetrazolium-based colorimetric (MTT) assay. The radical inhibition was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging techniques. The nitric oxide inhibitory activity was determined using LPS-activated RAW 264.7 macrophages. The correlation between radical scavenging capacity and antiproliferative activity was also analysed.ResultsThe extract from leaves of Sarcocephalus pobeguinii (LSP) exhibited the highest cytotoxic effect on all four of the human cancer cell lines but with some cytotoxicity to the normal Vero cells. However, the LSP extract had the best selectivity index, ranging from 3.15 to 18.28. Also, antioxidant and anti-inflammatory assays indicated that the LSP extract had the highest radical scavenging capacity of all the extracts. A positive linear correlation was found between free radical scavenging ability and antiproliferative activity against the four cancer cell lines, with the highest correlation factor (R2 = 0.9914) obtained between DPPH inhibition and antiproliferative activity against A549 cells.ConclusionsThe high selectivity index of the Sarcocephalus pobeguinii leaf extract indicates the potential of using this extract in cancer therapy. Furthermore, the positive correlation between free radical scavenging and antiproliferative activity suggests that the radical scavenging capacity of extracts may contribute to a prediction of their anticancer property.

English

This study aimed to assess the rootstocks influence over total phenolic compound content, antioxidant activity and its correlation in different red and white grapes cultivars for wine production. This study conducted an experimental three-year-old vineyard, located in Jundiai, in the State of Sao Paulo, Brazil, from July 2013 to January 2014. Red and white grapes from Vitis vinifera L. (Cabernet Sauvignon, Cabernet Franc, Merlot, Syrah and Sauvignon Blanc), V. labrusca L. (Isabel and Bordo) and hybrid cultivars (IAC 138-22 Maximo, BRS Violeta, IAC 116-31 Rainha, IAC 21-14 Madalena and BRS Lorena) were grafted on IAC 766 and 106-8 Mgt rootstocks. Samples of grapes were collected and the total carotenoids, chlorophyll, anthocyanin, flavonoid, and phenolic content, and the in vitro antioxidant activity determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. The rootstocks effects on red grape were mainly observed on the anthocyanins content. The total polyphenols content and the grapes antioxidant activity was virtually not affected by the rootstocks, especially on grapes of BRS Violeta and IAC 138-22 Maximo kinds, which presented the highest content of this compost. Among the white grapes, the 106-8 Mgt rootstock favored the increase of total phenolic compounds content on grapes of Sauvignon Blanc, IAC 116-31 Rainha and IAC 21-14 Madalena kinds. Although the hybrid grapes of IAC 116-31 Rainha e IAC 21-14 Madalena kinds are white grapes, the total phenolic compounds content on them were higher than the ones found on the red grape Isabel. Key words: Vitis vinifera, Vitis labrusca, hybrid grapes, total anthocyanin, Folin-Ciocalteau, 2,2-diphenyl-1-picrylhydrazyl (DPPH).

Antioxidant Properties of Popular Turmeric(Curcuma longa)Varieties from Bangladesh

We investigated the aqueous and ethanolic extracts of different forms (local names:muraandchora) of turmeric(Curcuma longa)from the Khulna and Chittagong divisions of Bangladesh for their antioxidant properties and polyphenol, flavonoid, tannin, and ascorbic acid contents. The antioxidant activity was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity and ferric reducing antioxidant power (FRAP) values. The ethanolic extract of Chittagong’s mura contained the highest concentrations of polyphenols (16.07%), flavonoids (9.66%), and ascorbic acid (0.09 mg/100 g) and chora resulted in high yields (17.39%). The ethanolic extract of Khulna’s mura showed a higher DPPH radical-scavenging activity with the lowest 50% inhibitory concentration (IC50) (1.08 μg/mL), while Khulna’s chora had the highest FRAP value (4204.46±74.48 μM Fe[II]per 100 g). Overall, the ethanolic extract had higher antioxidant properties than those in the aqueous extract. However, the tannin concentration was lower in the ethanolic extract. We conclude that the turmeric varieties investigated in this study are useful sources of natural antioxidants, which confer significant protection against free radical damage.

The anti-arthritic, anti-inflammatory, antioxidant activity and relationships with total phenolics and total flavonoids of nine South African plants used traditionally to treat arthritis.

BackgroundOxidative stress predisposes the human and animal body to diseases like cancer, diabetes, arthritis, rheumatoid arthritis, atherosclerosis and chronic inflammatory disorders. Hence, this study seeks to determine the antioxidant, anti-inflammatory and anti-arthritic activities of acetone leaf extracts of nine South African medicinal plants that have been used traditionally to treat arthritis and inflammation.MethodsThe anti-inflammatory activity of the extracts was determined by investigating inhibition of nitric oxide production in lipopolysaccharide activated RAW 264.7 macrophages as well as 15-lipoxygenase enzyme inhibition. An anti-protein denaturation assay was used to determine the anti-arthritic properties of the extracts. The antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethyl-benzthiazoline-6-sulfonic acid) (ABTS) radical scavenging assays and ferric reducing antioxidant power (FRAP). The total phenolic and total flavonoid concentration of extracts were determined by using standard methods.ResultsAll extracts inhibited nitric oxide production in a dose-dependent manner in the LPS-stimulated RAW 264.7 macrophages. Extracts of Maesa lanceolata and Heteromorpha arborescens inhibited NO production by 99.16 % and 89.48 % at a concentration of 30 μg/ml respectively. Elaeodendron croceum and Calpurnia aurea extracts had strong activity against 15-lipoxygenase activity with IC50 values of 26.23 and 34.70 μg/ml respectively. Morus mesozygia and Heteromorpha arborescens extracts had good in vitro anti-arthritic activity with IC50 values of 11.89 and 53.78 μg/ml, the positive control diclofenac sodium had IC50 value of 32.37 μg/ml. The free radical scavenging activity of the extracts in DPPH assays ranged between 7.72 and 154.77 μg/ml. Trolox equivalent antioxidant capacity (TEAC) and FRAP values ranged from 0.06 to 1.32 and 0.06 to 0.99 respectively.ConclusionsResults from this study support the traditional use of the selected medicinal plants in the management of arthritis and other inflammatory conditions. The free radical scavenging capacity of the extracts may be related to an immune boosting potential.

Variations in Essential Oil Yield, Composition, and Antioxidant Activity of Different Plant Organs from Blumea balsamifera (L.) DC. at Different Growth Times

Blumea balsamifera, also named Ainaxiang, is widely used as an ancient medicinal herb in tropical and subtropical Asia. It is rich in essential oils. In this work the essential oils of B. balsamifera from different plant organs and in different months were extracted, and then analyzed by gas chromatography-mass spectrometry. The results showed that essential oil yield of young leaves was the highest (0.65 mL/100 g), followed by mature leaves (0.57 mL/100 g), and the oil yield was higher in October (0.47 mL/100 g) than other months. A total of 44 compounds were identified, representing 92.64%–96.71% of the oil. Eighteen common chemical components were found among the six plant organs, representing >80% of the oil constituents. l-borneol was the main ingredient in leaves, and its content was the highest in senescent leaves and in December. In the essential oils of young shoots and young stems, the main component was dimethoxydurene. Antioxidant activity was also determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene bleaching (BCB) assays. The results indicated that the β-carotene bleaching activity was far stronger than the DPPH radical-scavenging capacity, and the young leaves and young shoots showed stronger antioxidant activity. Dimethoxydurene, β-caryophyllene, and α-caryophyllene play a positive role in good antioxidant activity, while β-eudesmol, phytol, and tetradecanal play a negative role. The antioxidant activity revealed in this study might help in developing this promising bioresource for use in the medicinal and cosmetic industries.

Characterization of the natural products in cocoyam (Colocasia esculenta) using GC–MS

Context: There is paucity of information in literature on the natural products in cocoyam [Colocasia esculenta Linn (Araceae)] that confer it with biological properties.Objectives: This study investigated the antioxidant properties of C. esculenta and also reported for the first time the natural products in C. esculenta that justify its biological properties.Materials and methods: The antioxidant activity of the methanol extract (50–250 μg/mL) of C. esculenta was determined using the 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical and reducing power assays. Characterization of the natural products in C. esculenta was done using the gas chromatographic–mass spectrometric (GC–MS) technique. The experiment lasted for 3 months.Results: GC–MS analysis of methanol/chloroform extract of the flour of C. esculenta indicated the presence of eight compounds, namely hexadecanoic acid methyl ester (0.43%), octadecanoic acid (20.91%), 9,12-octadecadienoyl chloride (0.77%), 11-octadecenoic acid methyl ester (2.12%), 9-octadecenoic acid (64.37%), 3-hexadecyloxycarbonyl-5-(2-hydroxylethyl)-4-methylimidazolium(1.36%), hexanedioic acid, bis(2-ethylhexyl)ester (1.36%) and 3,5-di-t-butyl phenol (3.27%). The total phenolic content of C. esculenta was 15.15 ± 0.35 mg Gallic Acid Equivalence/g and it was significantly higher (p < 0.05) than the total flavonoid (8.50 ± 0.42 mg Quercetin Equivalence/g) and condensed tannin (4.40 ± 0.14 mg Catechin Equivalence/g) contents, respectively. C. esculenta possessed strong antioxidant capacity though it was lower than that of standard quercetin.Discussion and conclusion: Results showed that C. esculenta possesses strong antioxidant activity and also contains some important bioactive compounds that justify its medicinal properties as used in ethno-medicine.

Antioxidant activities of Pistacia atlantica extracts modeled as a function of chromatographic fingerprints in order to identify antioxidant markers

Pistacia atlantica belongs to the Anacardiaceae family, and originated from the Atlas mountains of north Africa, which has been employed in traditional medicine for the treatment of various diseases. There are many limitations regarding their activities. The bioactive compounds present in the extract of P. atlantica leaves are not well defined. For these identifications HPLC fingerprint methodology can be used. In the present study, 28 extracts were obtained from male and female leaves of P. atlantica, collected monthly during 6months, in two different growing regions. The total antioxidant capacity (TAC) values of P. atlantica extracts were determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical method and the potassium ferricyanide (PFC) reduction method. The fingerprints were pre-treated using several techniques, such as column centering; normalization followed by column centering, and standard normal variate (SNV) transformation followed by column centering; each after initial alignment of the chromatographic profiles with Correlation Optimized Warping (COW). The multivariate calibration methods, Partial Least Squares (PLS) and Orthogonal Projections to Latent Structures (O-PLS), were employed to model TAC. The regression coefficients of the best models were evaluated to indicate the peaks probably responsible for the antioxidant activity. The O-PLS model seems preferable because of its better predictive and describing abilities, and its good interpretability of the contribution of compound peaks to the TAC. Several peaks in the chromatograms were recognized as importantly contributing to the model due to their large regression coefficients. The structural elucidation of the relevant peaks was achieved by negative ionization LC–QTOF–MS. The phenolic compounds galloylquinic acid, quinic acid and gallic acid mainly seemed to be responsible for scavenging the DPPH radical, while glucogallin, trigalloylglucose, gallic acid and tetragalloylquinic acid were considered specifically important for the prediction of TAC determined by the PFC method.

Evaluation of in Vitro Anti-inflammatory and Antioxidant Activity of Selected Zimbabwean Plant Extracts

ABSTRACTThe in vitro anti-inflammatory and antioxidant activities of Zimbabwean medicinal plant extracts were investigated by COX-1 and COX-2 enzyme inhibitory activity, the erythrocyte membrane stabilization, and albumin denaturation inhibition assays; free-radical scavenging activity of the plant extracts was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and tetramethoxy azobismethylene quinone (TMAMQ) radical scavenging assays. Combretum zeyheri, C. molle, and Parinari curatellifolia inhibited COX-2, inhibiting COX-1 the least with inhibitions of 42, 68, and 77%, respectively, for COX-2. C. platypetalum selectively inhibited COX-2 by 85% and COX-1 inhibition by 42%. IC50 of C. platypetalum and indomethacin for COX-2 were 571 and 414 µg.mL–1, respectively. C. platypetalum, C. molle, and Brachystegia boehmii stabilized the erythrocyte membrane and inhibited the precipitation of proteins in vitro. Plant extracts that inhibited the COX enzymes were tested for antioxidant activity using the DPPH and the TMAMQ free-radical scavenging assays. P. curatellifolia extract showed potent antioxidant activity in both assays with 100% of the radicals quenched at 16 and 18 µg.mL–1, respectively.

Mineral, Nutritional, and Phytochemical Profile, Total Phenolic Content, and Radical Scavenging Activity of Philippine Bamboo "Bolo"Gigantochloa levis(Blanco) Merr. Leaves

The study is a pioneering effort to determine the mineral, nutritional, and phytochemical composition and phenolic content and to determine the free radical scavenging activity of Gigantochloa levis (Blanco) Merr, a native bamboo species (locally known as “bolo”) in the Philippines. Proximate analysis showed that air-dried G. levis leaves contain 15.8% ash, 22.6% crude protein, 1.2% crude fat, 29.3% crude fiber, and 19.7% total sugar. Phytochemical tests indicated the presence of diterpenes, triterpenes, saponins, phenols, tannins, and flavonoids in both the ethanolic and aqueous leaf extracts, while phytosterols were only detected in the ethanolic extract. Folin-Ciocalteu assay determined the total phenolic content in gallic acid equivalents (GAE) to be 85.86 ± 3.71 and 32.32 ± 1.01 mg GAE/100 g dried sample for the ethanolic and aqueous extracts, respectively. The total phenolic content in quercetin equivalents (QE) was 74.44 ± 3.11 and 29.43 ± 0.85 mg QE/100g dried sample for the ethanolic and aqueous extracts, respectively. The radical scavenging activity of the different solvent fractions containing varying concentrations of the extract was determined using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. The ethyl acetate and 1-butanol fractions were found to have the highest radical scavenging activity. Mineral analysis via Energy Dispersive X-Ray Spectrometry (EDS) of the ash of G. levis leaves showed that Si is the major component, followed by K and Mg. These results point to the potential of G. levis leaves as a source of minerals and bioactive compounds with medicinal value.

Evaluation of Total Phenolic Content and Antioxidant Activity in Ten Selected Mahaleb (Prunus mahaleb L.) Genotypes

Mahaleb (Prunus mahaleb L.) is an important rootstock for P. avium and P. cerasus cultivars. The present study has compared the phenolic contents and antioxidant activity of the methanolic extracts of the barks, leaves and fruits of ten selected mahaleb genotypes. The total phenolic content (5.11-131.77 mg GA g-1) in barks and the total flavonoid (54.06-180.6 mg QE g-1) and proanthocyanidin (8.89-25.33 mg CA g-1) contents in fruits were greater than the other parts of the plants. The maximum contents of total phenol and total proanthocyanidin were in the stem bark and fruit of the genotype '249' (131.77 mg GA g-1, 25.33 mg CA g-1, respectively), while the maximum contents of flavonoid, and anthocyanin were in the fruits of genotype 271 (180.6 mg QE g-1 and 260.81 mg CY g-1, respectively). Antioxidant activity of the samples was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and reducing power assay (RPA). The antioxidant activity was the highest with the genotype '249', which showed 80.9% and 89.3% in DPPH and RPA assays, respectively. This study showed that total phenolic, flavonoid, proanthocyanidin, and anthocyanin contents were affected by mahaleb genotypes. This information may be of assistance in the production of mahaleb genotypes with maximum levels of desired phenolic.

SHELF-LIFE AND FREE RADICAL SCAVENGING ACTIVITY OF HARVESTED EGGPLANT (SOLANUM MELONGENA L.) COATED WITH PHYTOCHEMICAL EXTRACTS

The study was conducted to evaluate the shelf-life of harvested eggplant coated with phytochemical extracts and to assess the free radical scavenging activity (FRSA) of the coated fruits upon storage. ‘Morena’ hybrid eggplant fruits were coated with phytochemical extracts derived from cat’s whisker (Orthosiphon aristatus (Blume) L), hagimit (Ficus minahasse Miq.), and turmeric (Curcuma longa L.). The extraction of phytochemicals was accomplished using distilled water, ethanol, and acetic acid solvents. The concentration of the phytochemical extracts as coating solutions was set at 1% and the fruits were coated for a dipping time of 1 minute only. FRSA was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay with Trolox as the standard. The results showed that the shelf-life of eggplant was significantly enhanced by the phytochemical coatings. The acetic acid turmeric and ethanolic cat’s whisker extracts best enhanced the shelf-life of eggplant fruits for eight and 7.7 days, respectively. The untreated eggplants and those treated by the extracting solvents showed a shelf-life of about four days only. This significant difference in the shelf-life of coated fruits can spell a big leap on the profitability of the said vegetable. The freshly harvested mature fruit of eggplant has an average free radical scavenging activity of 338.2 µmol TE/100 g sample.

Radical Scavenging and Antioxidant Activities of Essential Oil Components – An Experimental and Computational Investigation

The antioxidant activities of eighteen different essential oil components have been determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay, the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical cation assay, and the ferric reducing antioxidant power (FRAP) assay. The phenolic compounds, carvacrol, thymol, and eugenol, showed the best antioxidant activities, while camphor, menthol, and menthone were the least active. The structural and electronic properties of the essential oil components were assessed using density functional theory (DFT) at the B3LYP/6-311++G** level. Correlations between calculated electronic properties and antioxidant activities were generally poor, but bond-dissociation energies (BDEs) seem to correlate with DPPH radical-scavenging activities, and the ferric reducing antioxidant power (FRAP) assay correlated with vertical ionization potentials calculated at the Hartree-Fock/6-311++G** level.

Antioxidant Activity and Chemical Constituents of Microalgae Oil of &lt;i&gt;Schizochytrium aggregatum&lt;/i&gt;

Abtrast: This research aimed to explore the antioxidant activity of microalgae oil through in vitro experiment and investigate the constituents of microalgae oil. The antioxidant activity was determined using the 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical scavenging assay,2,2-Azinobis (3-ehtylbenzothiazolin-6-sulfnicAcid)(ABTS)radical scavenging assay, the reducing power,β-Carotene bleaching assay and Oxygen Radical Absorption Capacity(ORAC)assay. BHT、α-tocopherol or Vc were compared as the reference. It can be confirmed that microalgae oil has moderate antioxidant ability. According to GC-MS analysis, the most abundant compounds in microalgae oil were palmitic acid, docosahexaenoic acid and tetradecanoic,constituting 38.1%, 34.24% and 3.39%, respectively.

Polarity of extracts and fractions of four Combretum (Combretaceae) species used to treat infections and gastrointestinal disorders in southern African traditional medicine has a major effect on different relevant in vitro activities

Ethnopharmacological importanceGastrointestinal disorders and infections are the major pathoaetiologies of diarrhoea causing many problems in human health and animal production. Many Combretum species are used in traditional medicine to treat infectious diseases including diarrhoea and many other ailments by rural people in Africa and Asia. Much of the work done to date on this genus was on the non-polar or intermediate polarity components. Some parameters that may cause diarrhoea and the evaluation of more polar extracts have apparently not been investigated. AimsThe polar components were extracted and fractionated by solvent–solvent fractionation to yield fractions with different polarities. The activity of these fractions on different parameters that could be involved in factors associated with diarrhoea was investigated. The cytotoxic activities of the extracts were also determined to evaluate the potential of these extracts to combat diarrhoea in production animals. Materials and methodsPhenolic-enriched leaf extracts of Combretum bracteosum (COB), Combretum padoides (COP), Combretum vendae (COV) and Combretum woodii (COW) were obtained by extracting with a mixture of 70% acetone acidified with 1% HCl and n-hexane. Acetone was removed from a portion of the 70% acetone extract and it was sequentially treated by solvent–solvent fractionation with dichloromethane, ethyl acetate, and butanol to yield fractions with a large variation in polarity. The phenolic constituents of the extracts and fractions were determined using standard procedures The antioxidant activities were determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH); 2,2′-azino-bis (3-ethylbenzothiazoline)-6-sulphonic acid (ABTS+) radical scavenging, ferric reducing antioxidant power (FRAP) methods and lipid peroxidation inhibitory capacity standard methods. The ferric reducing antioxidant activities of the fractions were also determined. The minimum inhibitory concentrations (MICs) of the crude extracts and fractions against four bacterial and three fungal strains were assessed with a microplate serial dilution method. Cyclooxygenase (COX) and lipoxygenase (LOX) enzyme inhibitory assays and cytotoxicity studies against Vero cells were also carried out. ResultSome of the fractions had much higher antioxidant activity than the positive controls. The average EC50 values of the extracts for the DPPH and ABTS antioxidant assays were 0.21–12µg/ml (COP), 0.25–16µg/ml (COV), 0.33–9.41µg/ml (COW) and 4.97–85µg/ml (COB) respectively while the mean EC50 values for the positive controls ascorbic acid and trolox were 1.28–1.51 and 1.02–1.19µg/ml respectively. All the crude extracts inhibited lipid peroxidation of linoleic acid by more than 80% at a concentration of 64 µg/ml. COP had the highest antibacterial activity with MICs ranging between 19–2500µg/ml, followed by COV with MICs ranging between 39–625µg/ml; COW and COB had similar MICs ranging between 39–2500µg/ml. COP also had the highest antifungal activity with MICs between 19–625µg/ml. The MIC for COW and COV ranged from 19 to 1250 µg/ml. COB had the lowest antifungal activity (MIC values were between 39 and 625 µg/ml). In general non-polar fractions had a high antimicrobial activity and polar fractions had a high antioxidant activity. The extracts had no activity against COX 1 and 2 enzymes in the anti-inflammatory assay but had good lipoxygenase inhibition. The crude extracts had high concentration of hydrolysable tannin (gallotannin). A good correlation (R2= 0.99) was found between the antioxidant activity and total tannin content indicating that, gallotannins may be responsible for the antioxidant activity. ConclusionThe results obtained in this study with more polar extracts indicate that the use of extracts of these plant species as antidiarrhoeal agents may have a scientific basis. The extractant used here extracted a much higher percentage of the phytochemicals than acetone. It was better for isolating antioxidant compounds (polar) but not good for isolating antimicrobial compounds (non-polar) from the same species compared to acetone, ethyl acetate, dichloromethane, and hexane.

Anti-rheumatoid arthritic activity of flavonoids from Daphne genkwa

The aim of the study was to investigate the anti-rheumatoid arthritic activity of four flavonoids from Daphne genkwa (FFD) in vivo and in vitro. Flavonoids of D. genkwa were extracted by refluxing with ethanol and purified by polyamide resin. An in vivo carrageenan-induced paw edema model, tampon-granuloma model and Freund's complete adjuvant (FCA)-induced arthritis mouse model were used to evaluate the anti-rheumatoid arthritic activities of FFD. Moreover, nitric oxide (NO) release and neutral red uptake (NRU) in lipopolysaccharide (LPS)-induced murine macrophage RAW264.7 cells were used to evaluate the anti-inflammatory effect in vitro. In addition, antioxidant effect of FFD was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. A high dose of FFD significantly reduced the degree of acute inflammatory paw edema in mice as a response to carrageenan administration (p<0.01). FFD displayed a dose-dependent inhibition of granuloma formation in mice (p<0.05). FFD also inhibited chronic inflammation in adjuvant-induced arthritis rats when administered orally at the dose of 50mg/kg/day (p<0.001). In addition, FFD suppressed the production of NO and exhibited immunoregulatory function in LPS-activated RAW264.7 cells in a dose-related manner. Simultaneously, FFD revealed conspicuous antioxidant activity with IC50 values of 18.20μg/ml. FFD possesses significant anti-inflammatory and antioxidant activity, which could be a potential therapeutic agent for chronic inflammatory disorders such as rheumatoid arthritis.