Photochemiluminescence Research Articles

Antioxidant content and volatile composition of seedless table grape (Vitis vinifera L.) varieties

Grapes are important sources of phenolics, which are recognized to possess high biological value. In this work, we evaluated the total phenol content (TPC), total anthocyanin content (TAC), antioxidant activity (AA) and volatile composition of unstudied seedless table grape varieties (i.e., Autumn Crisp and Pristine as white cultivars, Scarlotta and Crimson as red cultivars and Adora and Melody as black cultivars). As a result, Adora and Melody exhibited higher TPCs, TACs and AA, measured by the 2,2-diphenyl-2-picrylhydrazil (DPPH) and photochemiluminescence (PCL) assays, than the rest of the varieties. A comparison between the two black cultivars proved that Adora possessed higher TPC (62.70 mg GAE 100 g−1), DPPH radical scavenging activity (IC50 of 3.69 mg ml−1) and PCL antiradical activity (72.14 µg Trolox ml−1) than Melody (47.30 mg GAE 100 g−1, IC50 of 5.0 mg ml−1 and 42.36 µg Trolox ml−1, respectively). The volatile composition, determined by solid phase microextraction (SPME)–gas chromatography/mass spectrometry (GC/MS), indicated a similar qualitative aroma profile for all varieties. However, quantitative differences were measured among them, which were reflected in distinct sensory perception by sensorial testing. From these results, Adora was selected for its antioxidant properties and flavor characteristics.

Antioxidant Activity, Probiotic Survivability, and Sensory Properties of a Phenolic-Rich Pulse Snack Bar Enriched with Lactiplantibacillus plantarum

Pulse-based snack bars incorporated with probiotics were developed to provide an overview for the preparation of simple functional food concerning the antioxidant load and iron status improvement. The study focused on the application of microencapsulated probiotics in dry matrices, such as chickpeas and green lentils, in snack bars. The study aims to analyse the products’ antioxidative activities, chemical and sensory properties, as well as the probiotic survivability in the dry matrices. The basic chemical composition showed that 100 g of product can fulfil up to 4.4% and 3.3% of the daily iron value from chickpeas and green lentils, respectively (assuming the iron bioavailability is 23%). Sensory evaluation and hedonic analysis of the fresh pulse snack bar showed that panelists preferred the chickpea snack bar over the green lentil snack bar. For storage analysis, snack bars were stored at 20 °C and were vacuum packaged in sealed low density polyethylene (LDPE) pouches with no light exposure for two months. Hedonic analysis during storage showed significant differences in the aroma of the snack bars (p < 0.05). Generally, the antioxidant activities decreased during the two months of storage. A strong correlation was observed between total phenolic content (TPC) and antioxidant activity assays: ORAC (Oxygen Radical Absorbance Capacity), DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), PCL (Photochemiluminescence,). Moreover, after two months of storage, a 1-log decrease of probiotic viable cells was observed in both snack bars. To meet the dietary requirement of probiotics, it is suggested that people consume five portions and 9.4 portions of the chickpea and green lentil snack bars, respectively. The resulting products have promising properties with respect to probiotics and antioxidant potential in an unconventional way.

Characterisation of Muffins with Upcycled Sunflower Flour.

There is an increased interest and need to make our economy more circular and our diets healthier and more sustainable. One way to achieve this is to develop upcycled foods that contain food industry by-products in their formulation. In this context, the aim of this study was to develop muffins containing upcycled sunflower flour (a by-product from the sunflower oil industry) and assess the effects of sunflower flour addition on the fibre, protein, amino acid, mineral content, and antioxidant activity measured by a Ferric Reducing Antioxidant Power (FRAP) assay and Photo chemiluminescence (PCL) assay. Results show that the sunflower flour inclusion significantly improved all the parameters analysed as part of this study. A more balanced muffin amino acid profile was achieved, thanks to the increased levels of lysine, threonine, and methionine, the limiting essential amino acids of wheat flour. We can conclude that upcycled ingredients, such as sunflower flour, could be used for the nutritional improvement of baked goods, such as muffins. Their addition can result in several nutritional advantages that could be communicated on packaging through the use of the appropriate EU nutrition claims, such as those on protein, fibre, and mineral content.

Determinación de la capacidad antioxidante total de alimentos y plasma humano por fotoquimioluminiscencia: Correlación con ensayos fluorométricos (ORAC) y espectrofotométricos (FRAP)

La determinación de la capacidad antioxidante es útil para valorar la calidad de un alimento, la cantidad de antioxidantes presentes en un sistema, o la biodisponibilidad de compuestos antioxidantes en el cuerpo humano. Los métodos disponibles realizan la determinación del efecto potencial de las sustancias antioxidantes, presentes en los alimentos y en el organismo humano, contra las reacciones de oxidación. El objetivo fue comparar los resultados de la detección de la capacidad antioxidante total (CAT) en muestras de alimentos y plasma humano, mediante la quimioluminiscencia por fotosensibilización (PCL), en contraste con métodos que cuantifican la capacidad de absorbancia del radical de oxígeno (ORAC) y el poder antioxidante reductor del hierro (FRAP). Se obtuvieron extractos hidrosolubles y liposolubles de salvado de arroz estabilizado (SAE) y de harina de Ulva clathrata (HUC). El plasma se obtuvo de muestras de sangre humana (PHU). Se procesaron tres muestras en cada caso. Los resultados se analizaron mediante análisis de varianza de una vía y correlación de Pearson, p &lt; 0.05. La CAT determinada mediante PCL fue: SAE 246.37 ± 5.37, HUC 21.05 ± 0.41 y PHU 90.59 ± 1.17 equivalentes Trolox (ET) μmol /100 g ó 100 mL, p &lt; 0.05; ORAC: SAE 5015.62 ± 12.83, HUC 852.37 ± 3.45 y PHU 2563.31 ± 39.47 ET μmol /100 g ó 100 mL, p &lt; 0.05. FRAP: SAE 519.37 ± 0.04, HUC 52.78 ± 0.01 y PHU 90.26 ± 0.01 equivalentes Fe2+ (EFe2+) µmol /100 g ó 100 mL. Se observaron correlaciones entre PCL y ORAC, r = 0.99; y la PCL y FRAP, r = 0.94, ambas estadísticamente significativas (p &lt; 0.05). La PCL mostró ser un método confiable y alternativo para cuantificar la CAT, que se puede aplicar en estudios de alimentos y de intervenciones en salud.

DPPH free-radical scavenging activity, total phenolic contents and chemical composition analysis of forty-two kinds of essential oils

Forty-two commonly used essential oils were investigated for the antioxidant capabilities by DPPH free-radical scavenging activity, total phenolic contents and photochemiluminescence (PCL) assay. At the concentration of 5 mg/mL, cinnamon bark (91.4 ± 0.002%), origanum (86.66 ± 0.008%) and thyme wild (52.54 ± 0.016%) were shown to own the strongest DPPH free-radical scavenging activity. Their total phenolic contents were 658.40 ± 4.383, 1107.20 ± 0.768 and 275.50 ± 0.607 (μg GAE / 5 mg essential oil), respectively. To compare with the standard reference BHA (μg/mL), their EC50 were in the order: BHA (25.11 μg/mL) < cinnamon bark (90.63 μg/mL) origanum (62.63 ± 1.73 μmol trolox/g) > theme wild (5.88 ± 0.16 μmol trolox/g). The chemical compositions of cinnamon bark, origanum and thyme wild were analyzed by GC-MS and followed by DPPH free-radical scavenging activity assay to confirm that eugenol, carvacrol and thymol were the major compositions contributing the antioxidative capabilities of the essential oils.

Characterisation of the total phenolic, vitamins C and E content and antioxidant properties of the beebread and honey from the same batch

The aim of this study was to compare total phenolic and flavonoid content, antioxidant and reducing activity, as well as vitamin C and E content in beebread and honey. The antioxidant activity of samples was determined by photochemiluminescence (PCL) assay, while reducing potential was measured using FRAP and ORAC assays. Vitamin C was analysed by HPLC–MS-TripleTOF method and vitamin E by HPLC-DAD. Beebread was characterised by the higher level of the total phenolic (~90%), flavonoid (~97%), vitamin C (~99%) and E (~98%) as compared to the honey. The data showed that beebread had also higher values of antioxidant activity and reducing potential by ~99% and ~41–98%, respectively, than honey. Our findings indicate that beebread is valuable source of bioactive substances, with the high beneficial properties.

Chemical Composition and Biological Activity of Five Essential Oils from the Ecuadorian Amazon Rain Forest.

The chemical composition and biological activity of essential oils isolated from the leaves of Siparuna aspera, Siparuna macrotepala, Piper leticianum, Piper augustum and the rhizome of Hedychium coronarium were evaluated. These species are used medicinally in different ways by the Amazonian communities that live near the Kutukú mountain range. Chemical studies revealed that the main components for the two Siparuna species were germacrene D, bicyclogermacrene, α-pinene, δ-cadinene, δ-elemene, α-copaene and β-caryophyllene; for the two Piper species β-caryophyllene, germacrene D, α-(E,E)-farnesene, β-elemene, bicyclogermacrene, δ-cadinene and for H. coronarium 1,8-cineole, β-pinene, α-pinene and α-terpineol. The antioxidant activity of all essential oils was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), photochemiluminescence (PCL) quantitative assays, and DPPH and ABTS bioautographic profiles, with different results for each of them. Antimicrobial activity studies were carried out on three yeasts, six Gram positive and four Gram negative bacteria, by means of the disc diffusion method. The essential oil of H. coronarium showed the most relevant results on L. grayi, K. oxytoca and S. mutans, P. augustum and P. leticianum on S. mutans. An antibacterial bioautographic test for H. coronarium was also carried out and highlighted the potential activity of terpinen-4-ol and 1,8-cineole.

Inhibition of Advanced Glycation End-Product Formation by High Antioxidant-Leveled Spices Commonly Used in European Cuisine.

Spices and herbs, as good sources of polyphenols, could be strong inhibitors of advanced glycation end-product (AGE) formation. The aim of this research was to measure the ability of various spices to inhibit AGEs and to study the correlation of AGE inhibition with total phenolic (TP) content and antioxidant capacity. Fourteen spices commonly used in European cuisine were extracted with a 50% ethanol solution, and their water and total phenolic contents and antioxidant capacities were examined. Antioxidant capacity was evaluated using three methods: (1) Measurement of the radical scavenging ability of 2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and (2) 2,2-diphenyl-1-picrylhydrazyl (DPPH●); and (3) photochemiluminescence (PCL) assay. Antiglycation properties were studied in vivo using two model systems: Bovine serum albumin-glucose (BSA-glucose) and bovine serum albumin-methylglyoxal (BSA-MGO). The most potent glycation inhibitors, according to the BSA-MGO assay, were star anise (88%), cinnamon (85%), allspice (81%), and cloves (79%), whereas in the BSA-glucose measurement, oregano was noted to be a very effective inhibitor of the glycation process. The ability to inhibit glycation was highly correlated with TP values in the BSA-MGO and BSA-glucose assay (r = 0.84 and 0.76, respectively). Our research showed the high antiglycation ability of cinnamon, cloves, and allspice, and we suggest, for the first time, that anise could also be considered a good glycation inhibitor.

The Prognostic Value of Vitamin D Insufficiency &amp;amp; Vitamin D Receptor Gene Polymorphism in Adult Acute Myeloid Leukemia Patients

Background: Vitamin D regulates many aspects of cellular growth and differentiation in normal and cancer cells. There is growing evidence for both serum vitamin D level and VDR gene polymorphism as prognostic factors in hematologic malignancies. Aim of this work: Evaluation of vitamin D serum level and VDR FOKI polymorphism as prognostic factors in adult AML patients. Patients & Methods: Eighty subjects were included in this study, 50 adult patients with newly diagnosed AML and 30 apparently healthy controls matched for age and sex. Venous blood samples were withdrawn from all subjects for measurement of serum 25(OH) vitamin D using competitive photo chemiluminescence and molecular detection of VDR (FOKI) polymorphism, which was done by RFLP PCR. All patients received the standard induction chemotherapy regimen 3 & 7. Results: The rate of vitamin D insufficiency was significantly higher in AML patients compared to controls (58% vs 16%, p = 0.03). The mutant FOKI genotype (FF & Ff) was found in 52 % of patients compared to 23 % of controls (p = 0.02). Patient with sufficient vitamin D level showed a significantly higher complete response rate compared to those with insufficient level (90% vs 44%, p = 0.02), while none of the other clinical features showed significant relation. Patients with wild type FOKI polymorphism (FF) were more likely to have favorable cytogenetics, while patient with mutant FOKI polymorphism were more likely to have poor cytogenetics (p = 0.03). The CR rate was highest in the wild type FF group (87.5%) followed by the heterozygous Ff group (50%), while none of the patients in the homozygous ff group achieved CR (p = 0.04). Conclusion: VDR FOKI polymorphism and serum vitamin D level showed a significant impact on the treatment outcome of adult AML patients suggesting their potential role as prognostic factors in these patients. Longer follow up will be needed to study the impact on overall and disease free survival.

Antioxidant Activity as Biomarker of Honey Variety.

Honey variety is commonly defined by beekeepers based on nectar flow availability and the only laboratory method to provide verification is the melissopalynological analysis. Therefore, a quick and simple method for accurate assessment of honey variety is still being researched. The aim of the study was to evaluate the antioxidant activity of honey as an indicator of variety through the use of multivariate statistical analysis. Materials for the study consisted of 90 samples of varietal Polish honeys (rape-12, tilia-10, goldenrod-11, dandelion-5, buckwheat-6, multifloral-17, nectar-honeydew-8 and coniferous honeydew-16 and leafy honeydew-5) obtained directly from apiaries. Honeys were investigated in aspect of antioxidant capacity by photochemiluminescence (PCL) methods using standard ACW and ACL kits. As the reference FRAP and DPPH methods were used. The total phenolics content (TPC) was determined through the Folin-Ciocalteu method. The strongest antioxidant activity was found for buckwheat, while the weakest was found for rape honeys regardless of the used method. Results of the used methods were positively correlated (r = 0.42 to 0.94). Analysis conducted by PCL method confirmed that the minor fraction of honey antioxidants exhibits hydrophobic properties. Clear separation of honey varieties using PCA and Clustering method indicate that antioxidant activity can be a useful parameter for determining the botanical origin of honey.

Extractability of Polyphenols from Black Currant, Red Currant and Gooseberry and Their Antioxidant Activity

In this study, we analyzed extracts of Ribes (black currant, red currant and gooseberry) fruits obtained with methanol, methanol 50% and water. For each extract total polyphenol content, total favonoid content and total anthocyanin content was assessed. The antioxidant activity of extracts was evaluated by 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging capacity and by the photo-chemiluminescence (PCL) method. Identifcation and quantifcation of individual phenolic compounds was performed by means of high performance liquid chromatograph coupled with diode array detector (HPLC-DAD) analyses. From each fruit, best extraction of polyphenols was obtained with methanol 50%. In case of red currants and gooseberry there was no signifcant difference in favonoids and anthocyanins extraction rate by the different extraction solvents. For black currants the methanol and methanol 50% extract presented the highest antioxidant activity. For red currants extracts with methanol 50% showed stronger antioxidant activity (IC50 = 5.71 mg/ml for DPPH, IC50 = 1.17 mg/ml for ABTS) than those with methanol or water. In case of gooseberry by the DPPH test the water extract proved to be the most active (IC50 = 5.9 mg/ml). In the PCL test black currants methanol 50% extract was over 6 times more powerful as the ones from red currants. In case of gooseberries, water extract presented the highest antioxidant activity (41.84 μmol AAE/g). In black currant cyanidin-3-glucoside was the major compound. Quercetin 3-O-glucoside was identifed in each sample. From cinnamic acid derivatives neochlorogenic acid was present in black currants in the highest amount (356.33 μg/g).

Antimicrobial and antioxidant effects of combined high pressure processing and sage in beef burgers during prolonged chilled storage

Abstract The combined effect of sage (0.3 and 0.6%) and high pressure processing (HPP) [300 MPa (10 min, 9.9 °C) and 600 MPa (10 min, 10.2 °C)] on the antimicrobial and antioxidant characteristics of beef burgers during prolonged chilled storage (60 days) was analysed. Sage powder showed antioxidant and antimicrobial activities, but the addition of sage powder to burgers had no apparent effect on antimicrobial activity; however, antioxidant activity was detected as measured by TBARS, hexanal and photochemiluminescence (PCL). In general, lipid oxidation increased in all samples during storage. HPP at 600 MPa had no effect on lipid oxidation but caused mesophilic and psychrotrophic counts to remain close to the detection limit for at least 6 days. Significant correlations were found between lipid oxidation measured by TBARS and PCL and between TBARS with hexanal over the storage period. Sage had no detrimental effects on sensory attributes of burgers. Industrial relevance Sage is an aromatic plant with excellent antimicrobial and antioxidant properties. High pressure processing (HPP) is an efficient non-thermal preservation technology. As far as the authors are aware, very few studies have holistically addressed the question of stability (microbial spoilage and oxidation of lipids) of traditionally-prepared burgers as affected by HPP and addition of a natural plant. This paper examines the possible application of both treatments so as to obtain beef burgers with suitable oxidative and microbiological stability over prolonged chilled storage without this affecting sensory attributes.

The Use of the PHOTOCHEM Device in Evaluation of Antioxidant Activity of Polish Honey

Forty samples of varietal Polish honeys were investigated in order to assess their antioxidant capacity by photochemiluminescence (PCL) methods using standard ACW and ACL kits. The reference methods, FRAP and DPPH, were used. The total phenolics content (TPC) by Folin-Ciocalteau method was determined. The antioxidant properties of honeys as well as TPC were mainly dependent on honey botanical origin. The highest phenolic content and antioxidant activity for dark honeys, while the lowest for white honeys, were found. Moreover, the results obtained by used analytical methods were comparable and the best correlation between PCL and FRAP (r > 0.81) and DPPH (r = 0.74) methods was observed. The TPC in honeys was positively correlated with its antioxidant activity measured by PCL (r > 0.76). Used for the first time, PCL assay demonstrated usefulness in determining the antioxidant capacity of honey, divided into water-and lipid-soluble fractions, measured by ACW and ACL kits, respectively.

Interactions between lipophilic antioxidants measured by photochemiluminescence assay and α-tocopherol equivalent antioxidant capacity assay as well as the influence of matrix compounds on the lipophilic antioxidant capacity

Antioxidant capacity as sum parameter necessarily includes interactions between antioxidants. Thus, two compounds out of α-tocopherol, lycopene, β-carotene and lutein were mixed and measured by lipophilic photochemiluminescence (PCL) assay and α-TEAC assay. In the α-TEAC assay, all mixtures showed an antagonistic effect. The highest antagonistic effect was found for all mixtures of β-carotene and lutein. In contrast, in the PCL system antagonistic, synergistic and additive effects were detected. The mixture β-carotene and lutein 2:1 had the highest synergistic effects. The presence of functional hydroxyl groups and hydrogen bonding effects may have an influence on the interactions. In both assays used, we observed a concentration-dependent effect.The influences of glucose, fructose, saccharose and starch on the antioxidant capacity were determined by PCL and α-TEAC, too. All sugars can have an effect on the lipophilic antioxidant capacity depending on the extraction solvent. The sugar samples, extracted with n-hexane, did not show any antioxidant capacity in α-TEAC assay. In the PCL, the antioxidant potentials of sugars were dependent on the extraction solvent and reflected the dissolubility of sugars in methanol. The better the solubility the higher the antioxidant capacity. Additionally, sugars did not interact with antioxidants, with exception of the methanolic fructose extract.

Antioxidant activities of tocopherols/tocotrienols and lipophilic antioxidant capacity of wheat, vegetable oils, milk and milk cream by using photochemiluminescence

The purpose of this study was to measure the antioxidant activity (AOA) of tocopherols and tocotrienols by using photochemiluminescence (PCL). This method enables to detect total lipophilic antioxidants. The AOA of all vitamin E isomers depended on number and position of methyl groups in the chroman ring. Correlation between the AOA and the redox potential and the biological activity of the tocochromanols was observed. The second aim was to analyse different kinds of wheat, vegetable oils, milk and milk cream on their antioxidant capacity (AOC) by using PCL and α-TEAC. The contents of vitamin E and carotenoids were analysed by HPLC. Correlations between the sum of carotenoids and vitamin E and the AOC were detected. Based on high vitamin E contents, the oils had the highest and in contrast, the product macaroni showed the lowest AOC. A concentration-dependent effect was observed in both assays, PCL and α-TEAC.

Multivariate Analysis for Kinetic Modeling of Oxidative Stability and Shelf Life Estimation of Sunflower Oil Blended with Sage (Salvia officinalis) Extract Under Rancimat Conditions

In this research, sunflower oil-sage (Salvia officinalis) extract blends (SOSB) at nine different concentrations (200–2000 ppm), sunflower oil-tertiary butyl hydroquinone (TBHQ) (SOTBHQ) at 200 ppm, and control (no added antioxidant) were oxidized using Rancimat (temperature 100, 110, 120, and 130 °C; airflow rate 20 L/h). The resistance of the oil samples against oxidative stability was measured by induction period (IP). Oxidative stability index (OSI) and % antioxidant activity (AA) of oil samples were calculated and compared with photochemiluminescence (PCL) assay. The linear regression models were generated by plotting ln IP vs. temperature to estimate the shelf life as IP at 20 °C (R 2 > 0.90). The Arrhenius equation adequately described the temperature-dependent kinetics (R 2 > 0.90, p 0.90, p < 0.05) was obtained between OSI and PCL assay. The kinetic parameters together with multivariate analysis effectively screened 1200–1500 ppm of sage extract as the best concentration range conferring the highest oxidative stability to sunflower oil.

Fatty acid, carotenoid and tocopherol compositions of 20 Canadian lentil cultivars and synergistic contribution to antioxidant activities

Understanding the profile of lipophilic phytochemicals in lentils is necessary to better understand the health benefits of lentils. The fatty acid, carotenoid and tocopherol compositions and antioxidant activities of the lipophilic extracts of 20 lentil cultivars (10 red and 10 green) were therefore examined. Lentils contained 1.52–2.95% lipids, of which 77.5–81.7% were unsaturated essential fatty acids. Total tocopherols ranged from 37 to 64μg/g DW, predominantly γ-tocopherol (96–98% of the tocopherol content), followed by δ- and α-tocopherol. trans-Lutein was the primary and major carotenoid (64–78%) followed by trans-zeaxanthin (5–13%). Carotenoids and tocopherols showed weak correlation with 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity (r=0.4893 and 0.3259, respectively), but good correlation when combined (r=0.6688), suggesting they may act synergistically. Carotenoids were found to contribute the most to the strong antioxidant activity measured by photochemiluminescence (PCL) assay. Results from this study contribute to the development of lentil cultivars and related functional foods with increased health benefits.

SCREENING OF BIOLOGICAL ACTIVITIES FROM NOSTOC SPP. (CYANOPHYTA)

Screening of antioxidant activity (AA), total polysaccharide content (TPC) and angiotensin I-converting enzyme (ACE) inhibitor from Nostoc spp., maintained at TISTR Algal Culture Collection (TISTR-ACC) was conducted. The AA was tested by free radical scavenging of lipid phase (antioxidant capacity of lipid-soluble compounds-ACL) against superoxide anion (O2) using photochemiluminescence (PCL) assay. From seventy-one samples of crude extracts, N. punctiforme TISTR 8167 showed the best AA of 481.55 µmol (Trolox equivalent)/g (crude extract), followed by N. parmelioides TISTR 8174, Nostoc sp. TISTR 9102, N. paludosum TISTR 9004, Nostoc sp. TISTR 9073 and N. commune TISTR 8870, the activities of which were in the range of 348-390 µmol (Trolox equivalents)/g (crude extract). The total polysaccharide content (TPC) was determined by phenol-sulfuric acid assay. From fifty-two samples, the high TPC at ≥120 mg g-1 (dry cell weight), were found in three strains. The highest TPC at 130 mg g-1 was obtained from N. commune TISTR 8299. Angiotensin I-converting enzyme inhibitory activity (ACE-IA) and soluble protein content (SPC) of Nostoc strains were determined from 70 to 58 samples, respectively. The ACE-IA was tested by the detection of hippuric acid (HA) content from the reaction between hippuryl-histidyl-leucine (HHL) and ACE in the presence or absence of ACE inhibitor through simulated digestion of the samples. The results revealed that the high activities in the range 78-86% were obtained from N. commune TISTR 8160, N. muscorum TISTR 8164, N. paludosum TISTR 8890, N. entophylum TISTR 8161 and N. punctiforme TISTR 8167, by which N. commune TISTR 8160 expressed the highest inhibitory activity at 86%. The results of SPC quantified by Bradford assay were in the range 0.03-1.41 mg ml-1, N. micro-scopicum TISTR 9078, exhibited the highest SPC among the tested samples. However, these results show no relationship between ACE-IA and SPC.

ANTI-OXIDANT ACTIVITY AND NON-GENOTOXIC PROPERTY OF EXTRACTS OF 'LONGKONG' LANSIUM DOMESTICUM FRUITS

Lansium domesticum (Meliaceae) is an economic plant grown in the Southern, Eastern and Northern parts of Thailand. Fruit of L. domesticum (LD) is very popular in Thailand and commonly called ‘Longkong’. The aim of this study was to investigate anti-oxidant activity and genotoxicity property of L. domesticum fruits, particularly the skins and seeds. The air-dried samples of skin (SK) and seed (SD) were extracted with 50 and 95% ethanol. The ethanolic extracts were partitioned between dichloromethane (DCM) and 50% aqueous ethanol. The aqueous phase was further extracted with ethyl acetate (EA) to yield a total of 12 fractions. Their anti-oxidant capacity was determined on superoxide anion (O2-∙) scavenging by photochemiluminescence (PCL) assay, of both lipid (ACL) and water (ACW) soluble substance systems. The deoxyribose assay was also performed to assess their hydroxyl radicals (OH-∙) scavenging activity. Our results suggested that skin of L. domesticum fruits possessed higher antioxidant potential than seeds, particularly when extracted with 50% ethanol and partitioned with ethyl acetate, which had high potential both hydrophilic and lipophilic antioxidant substances. The genotoxicity effect of ethanolic extract of L. domesticum was investigated in TK6 human lymphoblasts using cytokinesis-blocked micronucleus (CBMN) assay. Mitomycin C (MMC) served as a positive control and results were analyzed on micronucleus (MN) frequencies in binucleated cells (BNC). We found that there was no significant increase in MN frequencies in L. domesticum-treated cells whereas MMC-treated cells clearly exhibited a marked increase in MN frequency (40-72 MN/1000 BNC). It indicated that the ethanolic extracts of L. domesticum seeds were non- genotoxic to TK6 cells.

Blood Pressure and Lipid Lowering Effects of Nigella sativa Seeds and Honey Mixture

The aim of this study was to investigate the effect(s) of a mixture ofNigella sativaseeds (N. sativa; black cumin or fennel) and honey on (i) the modulation of cardiovascular disease (CVD) risks among hypercholesterolemic and healthy subjects; and (ii) to assess the lipid-soluble antioxidants capacity of samples using the photochemiluminescence (PCL) method. Sixty-five subjects, aged twenty-five to fifty-eight, were enrolledand assigned to three groups. Two groups of healthy andhypercholesterolemic subjects were supplemented with N. sativa seeds and honey at 50 mg/kg (body weight) daily for three months. The third group served as control (healthy subjects without supplementation). Fasting blood samples were taken at baseline and again after three months of supplementation to measure (i) total cholesterol (TC), (ii) triglycerides (TG), (iii) low density lipoprotein-cholesterol (LDL-c), (iv) high density lipoprotein-cholesterol (HDL-c), (v) blood glucose, and (vi) hemoglobin concentrations. The findings were significant (p  0.05),indicatingthat N. sativa seeds mixed with honey had hypolipidemic, antiobesity and hypotensive effects.Results showed significant reductions in TG (20.1%), TC:HDL-c (12.3%),accompanied by increased HDL-c (15.0%) among healthy subjects.Supplementation also significantly decreased TC (6.2%), TG (13.3%), TC:HDL-c (19.5%),with increased HDL-c (8.4%) in the hypercholesterolemic group. Furthermore, there were significant reductions in body weight, body mass index and body fat by 2.3%, 2.2%, 4.5%, and by 1.8%, 1.9%, 4.5% in healthy and hypercholesterolemic subjects, respectively. Blood pressureslowering werealso observed in hypercholesterolemic subjects with significant reductions in systolic blood pressure (3.9%) and diastolic blood pressure (5.5%). There were no significant effectsfromsupplementation on blood glucose or hemoglobin concentrations. It is postulated that the positive effects observed may be due to antioxidant activity. The combination of of N. sativa seeds with honey showed higher synergistic effectswhen compared withsupplementation ofN. sativa seeds or honey on their own. Overall, these findings suggest that a mixture of N. sativa seeds with honey hasbeneficial effects in loweringthe citedrisk indicators for cardiovascular disease as a natural source of antioxidant activity; thus aidingthe maintainence of health bylowering CVD risk factors.