Beta-carotene Bleaching Assay Research Articles

Study on biological activity of Lavandula angustifolia and Citrus aurantiifolia essential oils

Abstract The essential oils of Lavandula angustifolia (lavender) and Citrus aurantiifolia (lime), have been used in several applications such as food industry, pharmacy, and cosmetics industries. In this report, we examined the biological activities of lavender and lime essential oils through several studies using β-carotene bleaching assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, antidiabetic assay, antibacterial assay, and also measure its total phenolic content (TPC). The functional group of lavender and lime was studied using Fourier transform infrared spectroscopy (FTIR), while the volatile compound was evaluated using Gas chromatography–mass spectrometry (GC-MS) analysis. The result showed that in DPPH assay, both of lavender and lime essentials oil have low activity with IC 50 of 1966.02 ppm and 4303.42 ppm, respectively, while in beta-carotene bleaching assay, lime has higher antioxidant activity of 39.03% compared to lavender as of 17.55%. Antibacterial activity against S. aureus showed that both lavender and lime have good activity as of 18.13 mm and 18.06 mm, respectively. The antidiabetic activity using α-glucosidase inhibitory activity presented that lavender and lime had high activity of 89.58 % and 88.30 %, respectively. Furthermore, the total phenolic content of lavender was slightly higher as of 480.00 mg GAE/g compared to lime as of 393.33 mg GAE/g. The GC-MS analysis of essential oils showed that lavender contains linalyl acetate (38.78%), linalool (36.12%), and 1,8-cineole (8.38%), while lime contains d-limonene (73.72%), beta-pinene (9.83%) and gamma-terpinene (8.24%), respectively. The present study showed the potential use of lavender and lime essential oils for antidiabetic, antimicrobial, and antioxidant agents.

Nutritional and Phenolic Antioxidant Properties of Pakistani Wheat Varieties as Influenced by Planting Period and Variety

The objective of this study was to investigate the effects of variety and plant environment on nutritional composition, phenolic contents and antioxidant activities from commercial wheat cultivars grown in Pakistan. Chemical composition, total phenolic contents and antioxidant activities were measured in twenty-seven spring wheat varieties grown for two cropping years. Preliminary assessment of antioxidant strength of the extracts was carried out by the evaluation of total phenolic contents (TPC), antioxidant activity (AA) and free radical scavenging activity (FRSA). The grain length, width and a thousand kernel weight of different wheat varieties ranged from 6.75-6.77 mm, 3.44-3.45 mm and 42.95-45.16 g respectively. Similarly, the moisture, ash, crude fat, crude fiber, crude protein, wet gluten, dry gluten, flour gliadins, flour glutenins contents and SDS-sedimentation value varied from 10.23-10.61%, 1.47-1.48%, 1.16-1.21%, 1.37-1.40%, 11.86-12.02%, 25.39-25.46%, 8.85-8.87%, 0.46-0.52%, 0.46-0.49% and 24.99-25.85 ml respectively among different wheat varieties. In the same way, the results for total phenolic contents, free radical scavenging activity (DPPH assay) and antioxidant activity via beta carotene bleaching assay varied from 12.40-11.73 mg GE/g, 18.48-18.99% and 14.23-15.97% respectively. Our research clearly indicated that wheat variety, input conditions, environmental and genotypic variations gave effects on the phenolic antioxidant properties.

Effects of extraction solvent and time on the oil yield, total phenolic content, carotenoid and antioxidant activity of Australian chia seed (Salvia hispanica L.) oil

The oil yield, total phenolic content (TPC), total carotenoid content (TCC) and antioxidant activity of Australian chia seed (Salvia hispanica L.) oil under solvents polarity and extraction times were studied. The chia seed oils were obtained by using organic solvents in the Soxhlet method with different extraction times including acetone 4 hrs (A4), acetone 8 hrs (A8) and hexane 8 hrs (H8) as a control. The oil yield for the control sample (36.1%) showed significant (p ≤ 0.05) higher than A4 (33.53%) and A8 (33.73%). TPC for chia seed oil (A4) was significantly higher (p ≤ 0.05) than A8 and H8. Meanwhile, chia seed oil (A8) contained the highest TCC over A4 and H8. The antioxidant activity of chia seed oil was determined by DPPH (2-diphenyl-1-picrylhydrazyl) scavenging activity, FRAP (Ferric reducing antioxidant power assay), BCBA (Beta-carotene bleaching assay) and TBA (Lipid Peroxidation Inhibition Assay), respectively. Chia seed oil obtained by acetone extraction for 4 hrs revealed higher antioxidant capacities (DPPH, BCBA and TBA) compared to chia seed oils from A8 and H8. However, chia seed oil (H8) showed the lowest total (phenolic and carotenoid contents) and antioxidant capacities. The correlation between the antioxidant content and the antioxidant activities were conducted to determine their relationship. TPC and TCC were strongly correlated with BCBA (r = 0.999) and TBA (r = 0.997). The results found Australian chia seed oil extracted by acetone for 4 hrs (A4) had higher contents of phenolic and antioxidant activity than control (H8) due to high polarity of acetone to the antioxidant compounds. In conclusion, acetone can be applied as an alternative extraction solvent to increase the total phenolic and carotenoid contents as well as antioxidant activity of Australian chia seed oil.

In vitro Antioxidant Potentiality of Purified Anthocyanin from Floral Petals of Wild Balsam Species

Phenolics are the largest group of phytochemicals ubiquitous in plant species with considerable interest economically. Recently, search of novel polyphenols increasingly becomes an area of intensive pharmacological research due to their multiple bioactive features such as antioxidant, antimicrobial, anti-carcinogenic, anti-viral and anti-inflammatory potentialities. Anthocyanins are flavonoid group of polyphenols, a group predominant in flowers, fruits and vegetables. The flavonoids, perhaps the unique single group of phenolics in foods, comprise a group of over 4200 C15 aromatic molecules with multiple structural patterns. The functions of anthocyanins as medicinal have been well-accepted in folk medicine throughout the world. In fact, these molecules are connected to an amazingly broad-based range of health benefits. In this juncture, the aim of this work was to evaluate the antioxidant activities of purified anthocyanin from wild balsam species. Initially, anthocyanin was extracted from floral leaves of wild balsam species and purified by chromatographic techniques. Subsequently, it was subjected to NMR and LC MS analysis. The major fractions identified were hesperidin, dimethoxy antirrhinin and trimethoxy antirrhinin. Further, the anthocyanin extracts were subjected to in vitro protocols like 2,2’-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical cation, DPPH scavenging assay, ferric reducing antioxidant power (FRAP), beta carotene bleaching assay, metal chelating and H2O2 scavenging power. Interestingly, ABTS, FRAP analyzes yielded significant results as compared to others. The data were comparable with that of synthetic antioxidants like ascorbate and catechin. Meanwhile, beta carotene and H2O2 scavenging assay showed moderate results. DPPH and metal chelating protocols displayed the values 71% and 64% respectively at 25 µg/ml concentration. This study provides model systems for the evaluation of natural antioxidants like anthocyanin. Future in vivo clinical studies are warranted to confirm the obtained data.

Central Composite Design as a Tools for Optimization of Antioxidant Activity on Cocoa Shell Extract

This study seeks to analyze and optimize the antioxidant activity thru beta carotene bleaching assay influenced by different extraction condition on extracts obtained from Malaysia Cocoa Shell. The condition was optimized by response surface methodology with five levels of the model. There are three variables involved in this study, namely: ethanol concentration (70-90 v/v %), temperature (45-65 ºC), and ultrasound irradiation time (30-60 min). The optimum condition obtains for temperature, duration of extraction and solvent concentration were 55 ºC, 45 minutes and 63.18% respectively at a constant frequency of 40 kHz. In this condition, the antioxidant activity experimental was 98.91±0.5% and predicted 98.44%. The ANOVA shows the coefficient of determination (R2) and the lack of fit test was 0.9846 and 0.6105 respectively. The desirability function from T-test data, modeled equation fits the data, reveals that the design can be used to predicting future observation within the design range.

Effects of thermo-vacuum treatment on secondary metabolite content and antioxidant activity of poplar (Populus nigra L.) wood extracts

A renewed interest in producing thermo-treated wood extracts and the potential applications of these extracts was observed in chemical, pharmaceutical, and food industries. Poplar (Populus spp.), belonging to the Salicaceae family, is one of the most cultivated woody plant for industrial purposes, one of the least expensive hardwoods, rarely used in the production of fine furniture, but extensively used for pulp and panel productions and have therefore an important economic impact worldwide. The aim of this study was to verify the influence of thermo-vacuum treatment (at 180, 200, and 220°C) on wood extracts obtained via three different extraction techniques: maceration, ultrasound-assisted extraction and accelerated-solvent extraction. Effect of temperature on extraction was verified by measuring the total contents of polyphenols, tannins and flavonoids. Secondary metabolites are often related to antioxidant activity measured by several in vitro tests, including the 2,2-diphenyl-1-picrylhydrazyl radical-scavenging method, the ferric-reducing-ability power test, and the beta-carotene bleaching assay. Our results showed the presence and the effect of heat treatments and extraction techniques on polyphenol and flavonoid contents. Extracts obtained from wood heated at 200 and 220°C showed the highest flavonoid and polyphenol contents, and, we observed a relationship with the shown antioxidant activity levels. Our study clearly showed the differential effects of temperature and extraction technique on both antioxidant activity and secondary metabolite contents. The detailed knowledge about the extractives from poplar wood can contribute, on the one hand, to better understand the effect of temperature during thermo treatment, and, on the other demonstrates the potential of this species as a source of bioactive compounds for nutraceutical or pharmaceutical applications by identifying appropriate extraction techniques.

Nutritional Compositions and Antiproliferative Activities of Different Solvent Fractions from Ethanol Extract of Cyphomandra betacea (Tamarillo) Fruit.

This study aims to examine various solvent extracts of Cyphomandra betacea (tamarillo) also known as the tree tomato, for their bioactive constituents and antioxidant activity. The study also aims to examine its effect on cancer cell death using two types of cancer cell lines (liver and breast cancer cell). The first part of the study evaluates the nutritional composition of tamarillo. Then, phytochemical profiling using GC-MS analysis in ethanolic tamarillo extract was conducted. Different fractions of n-butanol, ethyl acetate and aqueous fractions were obtained from the ethanolic extract of tamarillo. Then, the fractions were subjected to the quantification of total phenol (TPC) and flavonoid contents (TFC), free radical scavenging activity (SA) and also antioxidant activity (AOX) assayed by beta-carotene bleaching (BCB) assay. Finally, the capability of the ethanolic extract of tamarillo and different fractions were evaluated for their anticancer properties. Findings from this study revealed that the nutritional composition (ash, protein, carbohydrate and total dietary fiber), and mineral levels (calcium, magnesium, potassium and iron) of tamarillo were moderate. The crude ethanol extract of tamarillo contained the highest phenolic and total flavonoid content. FT-IR analysis revealed the presence of alkanes, carboxylic acid, phenol, alkanes, carboxylic acids, aromatics and nitro compounds. Twelve bioactive constituents in tamarillo have been identified through GC-MS analysis. Cytotoxic activity suggests the potential of ethanolic extracts of tamarillo having a chemopreventive effect on breast and liver cancer cells. This study reveals that tamarillo has substantial antioxidant activity as well as anticancer properties.

COMPARISON OF FIVE ANTIOXIDANT ASSAYS FOR ESTIMATING ANTIOXIDANT CAPACITY FROM THREE SOLANUM SP. EXTRACTS

<p>ABSTRACT<br />Objectives: The aims of this research were to determine antioxidant capacity of various extracts from black nightshade, turkey berry, and round<br />green eggplant using five antioxidant assays which were ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC),<br />H<br />2<br />O<br /> scavenging, phosphomolybdenum assay, and beta-carotene bleaching (BCB), correlation of total phenolic, flavonoid, and carotenoid content with<br />their inhibitory concentration 50% (IC<br />2<br />50<br />) and exhibitory concentration 50% (EC<br />) of five antioxidant assay and correlation between five antioxidant<br />assays.<br />50<br />Methods: Extraction was conducted by reflux using gradient polarity solvents. The extracts were evaporated using rotary evaporator. The antioxidant<br />capacity study, determination of phenolic, flavonoid, and carotenoid content were performed by ultraviolet-visible spectophotometry, while its<br />correlation with IC<br />50<br /> and EC<br />50<br /> of five methods were analyzed by Pearson’s method.<br />Results: Ethanolic and ethyl acetate fruit extracts of turkey berry denoted the highest antioxidant capacity using FRAP (EC<br />41.32 µg/ml),<br />H<br />2<br />O<br />2<br /> scavenging assay (IC<br />50: <br />1.01 µg/ml), and CUPRAC (EC<br />117.56 µg/ml). While ethyl acetate fruit extract of round green eggplant gave the<br />highest phosphomolybdenum capacity (EC<br />50<br />50: <br />: 375.47 µg/ml), and ethyl acetate fruit extract of black nightshade showed the highest BCB capacity<br />(EC<br />50: <br />158.66 µg/ml). Phenolic content of all fruit extracts had a tendency to correlate with FRAP and H<br />2<br />O<br /> scavenging antioxidant capacity, meanwhile<br />flavonoid and carotenoid content had a tendency to correlate with CUPRAC, phosphomolybdenum, and BCB antioxidant capacity.<br />2<br />Conclusions: Phenolic compounds were a major contributor in antioxidant capacity of black nightshade, turkey berry, and round green eggplant<br />extracts using FRAP and H<br />2<br />O<br /> scavenging, meanwhile flavonoid and carotenoid compounds were a major contributor in antioxidant capacity using<br />CUPRAC, phosphomolybdenum and BCB assays. FRAP assay had linear correlation with H<br />2<br />2<br />O<br /> scavenging, meanwhile CUPRAC had linear correlation<br />with phosphomolybdenum and BCB.<br />Keywords: Antioxidant, Antioxidant assays, Solanum fruits.<br />2</p><p>50:</p>

Production of fucoxanthin-rich fraction (FxRF) from a diatom, Chaetoceros calcitrans (Paulsen) Takano 1968

Fucoxanthin is the major carotenoid produced by diatoms and shown to exhibit potent anti-obesity and anti-cancer activities. This study presents a simple protocol for the preparation of fucoxanthin-rich fraction (FxRF) with high antioxidative properties from a selected marine diatom, Chaetoceros calcitrans. Fucoxanthin concentrates were prepared from crude methanolic extract (CME) with liquid–liquid partitioning of three types of solvent systems (i.e. diethyl ether–water, dichloromethane–water and ethyl acetate–water), followed by comparative antioxidant evaluation. Dichloromethane fraction (DCMF) was found to contain significantly higher (p<0.05) level of carotenoid (7.13±0.01mg·g−1DW) and fucoxanthin (5.25±0.03mgFX·g−1DW) contents accompanied with elevated (p<0.05) antioxidant activities (DPPH and ABTS+ radical scavenging, and beta carotene bleaching assays) as compared to other tested fractions. This study showed that FxRF with enhanced antioxidant properties could be effectively produced and concentrated through the DCM–H2O partition of CME.

Involvement of Calcium ion in Enhancement of antioxidant and antidiabetic Potential of Fenugreek Sprouts

Introduction: Calcium ion (Ca 2+ ) is considered as a key signal transducer in plants which is involved in various physiological processes. The aim of the present study was to evaluate the influence of Ca 2+ in enhancement of antioxidant as well as anti-diabetic activity of the fenugreek seedlings during developmental phase. Methods: The fenugreek seeds primed with Calcium chloride (CaCl 2 ), Calcium chelator EGTA [Ethylene glycol-bis(2-aminoethylether)-N,N,N´, N, tetra acetic acid] and calcium channel blocker LaCl 3 (lanthanum chloride) and germinated for 3 days. The sprout extracts were investigated for their antioxidant potential by DPPH, ABTS + , metal chelating, reducing power, nitric oxide scavenging capacity and anti-lipid peroxidation as well beta-carotene bleaching assays along with in vitro antidiabetic activity by α-amylase and α-glucosidase inhibition. Along with this, phytochemicals such as phenol, flavonol and carotene were also estimated. Results: The results demonstrated that the seeds treated with calcium chloride showed enhanced antioxidant as well as antidiabetic potential over control; on the other hand the action was reversed by EGTA and LaCl 3 . Similar trend was observed in the phytochemical contents of the sprouts. Conclusion: Our data suggested that the improvement in nutraceutical value of fenugreek sprouts by calcium chloride could be due to the involvement of Ca 2+ in signaling

Protective Effect of Bauhinia variegata Leaf Extracts Against Oxidative Damage, Cell Proliferation and Bacterial Growth

Present communication describes the therapeutic potential of Bauhinia variegata leaf extracts. Protection against oxidative damage was observed with several extracts as indicated by their antioxidant potential. Polar extracts namely, ethyl acetate, acetone and aqueous exhibited appreciable ferric reducing antioxidant power. Aqueous and benzene extracts accounted for significant free radical scavenging activity in beta carotene bleaching assay. Inhibition of lipid peroxidation was also displayed by aqueous extract in rat liver homogenate. Aqueous fraction demonstrated remarkable antiproliferative activity (91–99 %) against colon (Colo-205 and HCT-116) and lung (A549) cancer cell lines. However, lower activity was observed against prostate (PC-3), breast (T47D) and lung (NCI-H322) cancer cell lines. Low to moderate antibacterial activity was manifested by hexane, benzene, ethyl acetate and aqueous extracts against Proteus vulgaris (MTCC 7299), Salmonella typhi (MTCC 3917), Bordetella bronchiseptica (MTCC 6838), Bacillus cereus (MTCC 6840) and Streptococcus mutant (MTCC 497). The study revealed noticeable antioxidant, radical scavenging, anticancer and antibacterial potential in B. variegata leaf extracts.

Antioxidant and proapoptotic activities of Sclerocarya birrea [(A. Rich.) Hochst.] methanolic root extract on the hepatocellular carcinoma cell line HepG2.

The main goal of this study was to characterize the in vitro antioxidant activity and the apoptotic potential of S. birrea methanolic root extract (MRE). Among four tested extracts, obtained with different solvents, MRE showed the highest content of polyphenols, flavonoids, and tannins together with antioxidant activities tested with superoxide, nitric oxide, ABTS, and beta-carotene bleaching assays. Moreover, the cytotoxic effect of MRE was evaluated on the hepatocarcinoma cell line HepG2. In these cells, MRE treatment induced apoptosis and generated reactive oxygen species (ROS) in dose-dependent manner. The cytotoxic effect promoted by MRE was prevented by pretreatment of HepG2 cells with N-acetyl-L-cysteine (NAC), suggesting that oxidative stress was pivotal in MRE-mediated cell death. Moreover, we showed that the MRE treatment induced the mitochondrial membrane depolarization and the cytochrome c release from mitochondria into the cytosol. It suggests that the apoptosis occurred in a mitochondrial-dependent pathway. Interestingly, MRE showed a sensibly lower cytotoxicity, associated with a low increase of ROS, in normal human dermal fibroblasts compared to HepG2 cells. It is suggested that the methanolic root extract of S. Birrea is able to selectively increase intracellular ROS levels in cancer cells, promoting cell death.

Antioxidant and Cytoprotective Effects of an Ethanol Extract of Acalypha wilkesiana var. macafeana from Malaysia

In the annals of biomedical theory perhaps no single class of natural product has enjoyed more ingenious speculation than antioxidants formally aimed at counteracting oxidative insults which are involved in the pathophysiology of Alzheimer's and Parkinson's disease, cancer, amyotrophic lateral sclerosis, skin ageing and wound healing. In pursuing our study of Malaysian traditional medicines with antioxidant properties, we became interested in Acalypha wilkesiana var. macafeana hort., used traditionally to heal wounds. To examine whether Acalypha wilkesiana var. macafeana hort. could suppress oxidation an ethanol extract was tested by conventional chemical in vitro assays i.e., ferric reducing antioxidant potential assay (FRAP), DPPH scavenging assay and beta-carotene bleaching (BCB) assay. To explore whether Acalypha wilkesiana var. macafeana hort. protected cells against oxidative injuries, we exposed human hepatocellular liver carcinoma (HepG2) cells to tert-butylhydroperoxide (t-BHP). In all the aforementioned experiments, the ethanol extracts elicited potent antioxidant and cytoprotective activities. To gain a better understanding of the phytochemical nature of the antioxidant principle involved, five fractions (F1-F5) obtained from the ethanol extract were tested using FRAP, DPPH and BCB assays. Our results provided evidence that F5 was the most active fraction with antioxidant potentials equal to 2.090 +/- 0.307 microg/mL, 0.532 +/- 0.041 microg/mL, 0.032 +/- 0.025 microg/mL in FRAP, DPPH and BCB assay, respectively. Interestingly, F5 protected HepG2 against t-BHP oxidative insults. To further define the chemical identity of the antioxidant principle, we first performed a series of phytochemical tests, followed by liquid-chromatography and mass spectrometry (LC/MS) profiling which showed that the major compound contained in F5 was geraniin. To the best of our knowledge, this is the first report showing that the wound healing property of Acalypha wilkesiana var. macafeana hort. is mediated by a geraniin containing extract. Furthermore, our data leads us to conclude that geraniin could be used as a potential pharmaceutical and/or cosmetic topical agent.

Bauhinia variegata leaf extracts exhibit considerable antibacterial, antioxidant, and anticancer activities.

The present study reports the phytochemical profiling, antimicrobial, antioxidant, and anticancer activities of Bauhinia variegata leaf extracts. The reducing sugar, anthraquinone, and saponins were observed in polar extracts, while terpenoids and alkaloids were present in nonpolar and ethanol extracts. Total flavonoid contents in various extracts were found in the range of 11–222.67 mg QE/g. In disc diffusion assays, petroleum ether and chloroform fractions exhibited considerable inhibition against Klebsiella pneumoniae. Several other extracts also showed antibacterial activity against pathogenic strains of E. coli, Proteus spp. and Pseudomonas spp. Minimum bactericidal concentration (MBC) values of potential extracts were found between 3.5 and 28.40 mg/mL. The lowest MBC (3.5 mg/mL) was recorded for ethanol extract against Pseudomonas spp. The antioxidant activity of the extracts was compared with standard antioxidants. Dose dependent response was observed in reducing power of extracts. Polar extracts demonstrated appreciable metal ion chelating activity at lower concentrations (10–40 μg/mL). Many extracts showed significant antioxidant response in beta carotene bleaching assay. AQ fraction of B. variegata showed pronounced cytotoxic effect against DU-145, HOP-62, IGR-OV-1, MCF-7, and THP-1 human cancer cell lines with 90–99% cell growth inhibitory activity. Ethyl acetate fraction also produced considerable cytotoxicity against MCF-7 and THP-1 cell lines. The study demonstrates notable antibacterial, antioxidant, and anticancer activities in B. variegata leaf extracts.

Simulated Gastrointestinal pH Condition Improves Antioxidant Properties of Wheat and Rice Flours

The present study was conducted to evaluate the antioxidant properties of wheat and rice flours under simulated gastrointestinal pH condition. After subjecting the wheat and rice flour slurries to simulated gastrointestinal pH condition, both slurries were centrifuged to obtain the crude phenolic extracts for further analyses. Extraction yield, total contents of phenolic and flavonoids were determined as such (untreated) and under simulated gastrointestinal pH condition (treated). 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•) scavenging activity, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radical cation (ABTS•+) scavenging activity, ferric reducing antioxidant power (FRAP), beta-carotene bleaching (BCB) and iron chelating activity assays were employed for the determination of antioxidant activity of the tested samples. In almost all of the assays performed, significant improvements in antioxidant properties (p < 0.05) were observed in both flours after treatment, suggesting that wheat and rice flours contain considerably heavy amounts of bound phenolics, and that their antioxidant properties might be improved under gastrointestinal digestive conditions.

Antioxidant Activities of Essential Oil of Psidium Guajava L. Leaves

The antioxidant potential of guava leaves essential oil (EO) was evaluated by using free radical (DPPH) scavenging assay, reducing power assay and also beta-carotene bleaching assay. Here, butylated hydroxytoulene (BHT) and ascorbic acid were used as standard antioxidants. Guava leaves EO showed a concentration-dependent free radical scavenging activity by inhibiting the DPPH radicals but served as a moderate antioxidant with IC50 value of 460.37 ± 1.33μg/mL. Guava leaves EO possess moderate inhibition of oxidation of beta-carotene with percentage of inhibition (I %) value of 81.67 ± 1.48% in beta-carotene bleaching assay. The total phenolic content of guava leave EO was also evaluated spectrophotometrically according to Folin-Ciocalteu's phenol method and expressed in gallic acid equivalents (GAE). Remarkably high total phenolic content 495.93 ± 7.88mg of GAE/g of EO was obtained. This study revealed that guava leaves EO comprise moderate potential source of natural antioxidants.

Screening of Endophytic Fungi Having Ability for Antioxidative and α-Glucosidase Inhibitor Activities Isolated from Taxus sumatrana

Endophytic microbes are considered as an important source of natural products. They show antibiotic, anticancer, antioxidative and antidiabetic activities. Therefore, there are many reports on the isolation and bioactivity screening of endophytic fungi from various plants including Taxus species. Taxus sumatrana (Miq.) de Laub is found in Indonesia. The objective of this study is to conduct an in vitro screening of 14 endophytic fungi isolated from Taxus sumatrana having antioxidative and alpha-glucosidase inhibitor activities. Each endophytic fungus was cultured for 7 days and the fungal mycelium and medium were extracted with methanol and ethyl acetate, respectively, to produce each extract. The antioxidative activity of each extract was tested by DPPH free radical scavenging activity and beta-carotene bleaching assays, whereas antidiabetic activity was tested based on alpha-glucosidase inhibitor activity. The screening results showed that fungal mycelia of TSC 13 had the best alpha-glucosidase inhibitor activity and TSC 24 had the best antioxidative activity. Isolation of bioactive compounds from TSC 13 and TSC 24 is being conducted. This is the first report that endophytic fungi isolated from T. sumatrana exhibited anti alpha-glucosidase inhibitory and anti oxidative activities.

Fatty acid composition and antioxidant activity of oils from two cultivars of Cantaloupe extracted by supercritical fluid extraction

The effect of supercritical fluid extraction (SFE) fractionation of three oil fractions (1 st , 2 nd , 3 rd fraction) on the fatty acid composition and antioxidant activity of oils from two cultivars of cantaloupe were investigated. Rock melon oil (RMO) and Golden Langkawi oil (GLO) were extracted using SFE and the major fatty acids for both cultivars were linoleic, oleic, palmitic, and stearic acid. The SFA decreased from 15.78 to 14.14% in RMO 1 st fraction, and MUFA decreased from 18.30 to 16.56% in RMO 2 nd fraction, while PUFA increased from 65.9 to 69.30% in RMO 3 rd fraction. On the other hand SFA decreased from 16.35 to 13.91% in GLO 1 st fraction, and MUFA decreased from 17.50 to 15.57% in GLO 2 nd fraction, while PUFA increased from 66.15 to 70.52% in GLO 3 rd fraction. The different fractions of the two oils showed high antioxidant activity in reducing the oxidation of β-carotene in beta-carotene bleaching assay (BCB) and the quenching of 1,1-diphenyl-2-picrylhydrazyl (DPPH).

In vitro Antioxidative Activities and Polyphenol Content of Eugenia polyantha Wight Grown in Indonesia

Antioxidative activities of three bark extracts (methanol, methanol-water and water) from Eugenia polyantha Wight grown in Indonesia were evaluated using various in vitro assays; 2, 2-diphenyl-1-picrylhydrazyl radical-scavenging, hydrogen peroxide-scavenging and beta-carotene bleaching assays. From the assays, Eugenia polyantha bark extracts were found to be potential antioxidative activities. The methanol-water extract showed the highest level of free radical-scavenging activity (Effective dose (ED50) = 0.18 mg mL-1) and protection from beta-carotene bleaching (85.7% at 100 microg mL-1). The methanol-water extracts showed the highest total phenolic content (856 mg gallic acid equivalent (GAE)/g and 161 mg catechin equivalent (CE)/g) and total antioxidative capacity (449 mg ascorbic acid equivalent (AAE)/g). Furthermore, it exhibited dose-dependent antioxidative activities. A relationship between total antioxidative capacity and total phenolic content was recognized in the three extracts from Eugenia polyantha bark.

Phenolic Content and Antioxidant Activity of Primitivo Wine: Comparison among Winemaking Technologies

The aim of this study was to assess the influence of 9 winemaking technologies (traditional, delestage, saignée, delayed punching-down, addition of grape seed tannins, addition of ellagic-skin-seed tannins, heating of must-wine, cryo-maceration, and prolonged maceration) on the phenolic content and antioxidant activity of Primitivo musts and wines. Three methods for the determination of the antioxidant activity were compared: DPPH, beta-carotene bleaching assay, and ABTS. Oenological parameters and composition of the phenolic fraction of 1-y-aged wines was also determined. The addition of tannins allowed the increase of the phenolic content of musts and wines in a greater amount than the other technologies. The results concerning the antioxidant activity depended on the method applied. Concerning musts, the DPPH assay did not highlight great differences among technologies, whereas the addition of tannins allowed the obtainment of the highest antioxidant activity according to beta-carotene and ABTS assays. The wine aging determined an increase of the antioxidant activity, independently on the method applied. Wine obtained through traditional technology, saignée, and addition of tannins showed the highest antioxidant activities according to DPPH and beta-carotene. The highest correlation coefficients (0.961 and 0.932) were calculated between phenolic content and ABTS values of musts whereas the lowest values (0.413 and 0.517) were calculated between phenolic content and ABTS values of wines. Wines produced through traditional technology were the richest in anthocyanins. The addition of tannins allowed to obtain high content in monomeric anthocyanins, flavonoids, flavans reactive to vanillin, and coumaroylated malvidin and a low content in acetylated malvidin. Practical Applications: It is well known that a moderate consumption (equivalent to 2 glasses per day) of red wine is actually recommended since it appears associated with a decreased incidence of cardiovascular diseases. The mechanisms involved in this protective effect are not completely understood although they appear related to the presence of phenolic compounds. To increase the intake of these compounds without increase of the wine consumption, it is necessary to improve their extraction during maceration. This study could represent a helpful tool for wineries aimed to know the way to increase the antioxidant content of their wines, thus changing them in functional beverages and prolonging their shelf life.