IN VITRO ANTIOXIDANT AND ANTICANCER ACTIVITIES OF EXTRACTS FROM A FERMENTED FOOD

Solvent extracts were prepared from Manda Enzyme®, one of the fermented health foods, and their activities of radical scavenging and cancer cell growth inhibition were evaluated. Manda Enzyme® was extracted with 55% ethanol, and then fractionated into n‐hexane, chloroform, ethyl acetate, methanol‐soluble and methanol‐insoluble fractions. The antioxidant activities were in the order chloroform > ethyl acetate > other fractions and of each fraction were positively related to the amount of total phenolics and the intensity of brown color. The cancer cell growth inhibitory activities were in the order n‐hexane > chloroform > other fractions. Proliferation of HRT‐18, HCT‐48 and HepG2 human cancer cells was inhibited by the treatment of the n‐hexane fraction of Manda Enzyme® at a concentration of 400 μg/mL to the extent of 75, 89 and 90%, respectively. From these results, it is considered that Manda Enzyme® has chemically different ingredients showing strong antioxidant and anticancer activity in vitro.     

ANTIOXIDATIVE AND ANTIBACTERIAL POTENTIALS OF ESSENTIAL OILS AND EXTRACTS ISOLATED FROM VARIOUS SPICE MATERIALS†

The antioxidant and antibacterial potentials of essential oils and acetone extracts of black pepper, cumin, black cumin and mace were carried out by different techniques. The antioxidative capacity of the essential oils and acetone extracts were evaluated against mustard oil by measuring peroxide and thibarbituric acid values at fixed intervals. In addition, their antioxidant potential was evaluated by 2, 2′‐diphenyl‐1‐picrylhydracyl radical and conjugated diene assays. Their reducing power was determined with standards, which proved the strong antioxidant capacity of essential oils and extracts. The antioxidant activity of essential oils and extracts exerted by all the antioxidant assays can be compared with synthetic antioxidants such as butylated hydroxyanisole and butylated hydroxytoluene. The antibacterial activity was studied by disk diffusion and poison food methods. Black cumin essential oil showed complete zone of inhibition (P < 0.05) against tested bacterial strains of Staphylococcus aureus, Bacillus cereus and Bacillus subtilis at 2 and 6 µL level by disk diffusion method. Black cumin and black pepper extracts showed complete reduction of colonies against tested bacterial strains of S. aureus, B. cereus and B. subtilisat 5 and 10 µL level by poison food method. Poison food method exhibited good results for the tested essential oils and extracts. Essential oils of black pepper, cumin, black cumin and mace may be used to stabilize mustard oil after screening.     

罗汉果叶黄酮抗氧化能力研究

采用磷钼络合物法研究了罗汉果叶总黄酮提取物的抗氧化能力。结果表明，该提取物具有很强的抗氧化活性，其抗氧化活性优于人工合成抗氧化剂BHT，是一种值得进一步开发利用的天然抗氧化剂。     

ANTIOXIDANT ACTIVITIES OF ENDEMIC SIDERITIS LEPTOCLADA AND MENTHA DUMETORUM AQUEOUS EXTRACTS USED IN TURKEY FOLK MEDICINE

Total phenolic contents, hydroxyl radicals and one 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activities, antioxidant capacities and reducing powers of Sideritis leptoclada, which is an endemic plant to Turkey, and Mentha × dumetorum were investigated in water extracts. Total phenolic contents were detected to be 0.32 µg gallic acid/µg dry biomass in the presence of 1.33 and 9.82 µg/mL, respectively. Fifty percent scavenging activities of hydroxyl and DPPH radical were determined with 0.03 and 0.16 mg/mL extracts of S. leptoclada and 0.21 and 1.6 mg/mL extracts of Mxdumetorum. In addition, total antioxidant capacities of S. leptoplada were also higher than Mxdumetorum and there was a significant difference between the controls. The result of this study suggests that extracts of S. leptoclada and Mxdumetorum can be used as potential source of natural antioxidants and as a possible food supplement or in the pharmaceutical industry.

PRACTICAL APPLICATIONS

The research is focused on the determination of new potential plant sources of antioxidants that can be used as food. Antioxidants are vital substances that possess the ability to protect the body from damage caused by reactive oxygen species induced oxidative stress. In this study, infusions in boiled water of Sideritis leptoclada , which is a plant endemic to Turkey, and Mentha x dumetorum have high levels of antioxidant capacity. The results of the study show that extracts of S. leptoclada and Mxdumetorum can be used as a supplement agent to increase in quality of food and for the pharmaceutical industry.     

香菜乙醇提取液的体外抗氧化活性

采用Fenton反应体系产生羟自由基和邻苯三酚自氧化产生超氧阴离子自由基,研究香菜乙醇提取液对两者的清除作用.并以芦丁为时照品,测定其总黄酮含量.结果表明:香菜中总黄酮含量为8.493 mg/g.香菜乙醇提取液对羟自由基和超氧阴离子自由基均有清除作用,半数清除量(IC50)分剐为122.331 mg/L和71.535 mg/L,提取物浓度的添加量在试验范围内与其抗氧化活性呈正相关.     

BIOCHEMICAL CHARACTERIZATION OF BORAGE (BORAGO OFFICINALIS L.) SEEDS

Gas chromatography–mass spectrometry analysis of seed Borago officinalis essential oil (EO) revealed the presence of 16 volatile components. β-Caryophyllene (26%) and p-cymene-8-ol (19.7%) represented the major components, while nonadecane (0.7%) and hexanol (0.7%) were the minor ones. The EO composition was characterized by higher abundance of oxygenated monoterpenes (27.7%), followed by sesquiterpenes (26%). Fatty acid composition showed the predominance of linoleic (35.4%), oleic (24.2%) and γ-linolenic (20.4%) acids. Polyphenols were analyzed by reversed-phase high-performance liquid chromatography after acid hydrolysis of phenolic acid esters. Six phenolic acids were identified in seed extract and rosmarinic acid was the predominant one with 1.65 mg/g dry matter weight equivalent to 33% of total phenolic acids.

PRACTICAL APPLICATIONS

Borage ( Borago officinalis L.) is of great interest because of its medicinal and nutritional properties. In fact, thanks to its characteristic composition in fatty acids, particularly high levels of gamma-linolenic acid in its seed oil, borage has gained importance. The potent consumers of this medicinal plant are hypertensive and hypercholesterolemic people. Borage consumption is also recommended for people suffering from rheumatism and eczema.
Unfortunately, the knowledge about antioxidative/antiradical properties of borage is very scanty. So, recently, an extensive investigation was focused on the antioxidant properties of borage extracts. These extracts showed excellent antioxidant properties and their effects were attributed to their phenolic constituents. These antioxidants can be concentrated, either as crude extracts or individual phenolic compounds, to be used in highly unsaturated oils such as marine oils. Furthermore, borage consumption has been reported as a possible gastric cancer protective factor.     

ANTIOXIDANT ACTIVITY OF WHEAT CARYOPSES AND EMBRYOS EXTRACTS

Phenolic compounds were extracted with 80% methanol from caryopses and embryos of wheat (cv. Alba and Elena). In extracts the content of total phenolics was determined and UV spectra recorded. For all extracts the antioxidant activity in a β-carotene-linoleate model system, scavenging effect on DPPH radical, and reducing power were examined. Extracts of wheat embryos were characterized by a higher content of total phenolics. UV spectra of phenolic compounds extracted from wheat caryopses were characterized by maxima close to 320 nm due to phenolic acids, and by maxima at shorter wavelengths (272–280 nm) attributed to other phenolic compounds. The antioxidant activities of extracts from caryopses in a β-carotene-linoleate model system were higher than those from embryos. The results so obtained were similar to those observed previously for extracts of rye and triticale grains and leguminous seeds. The scavenging effect of wheat extracts on DPPH radical and their reduction power were weak, but those for embryos extracts were somewhat stronger.     

ANTIOXIDANT ACTIONS OF FRUIT, HERB AND SPICE EXTRACTS

The antioxidant properties of extracts of five fruits (apple, pear, peach, plum and grapefruit), three herbs (rosemary, tarragon and basil) and one spice (black pepper) were evaluated in a series of assays involving reactive oxygen species (ROS). In general, the crude extracts possessed potent antioxidant properties in vitro . Rosemary extract was 50-times more effective at preventing microsomal lipid peroxidation of human liver microsomes induced by NADPH/iron compared to peroxidation induced by iron/ascorbate, but tarragon was more effective in the iron/ascorbate dependent peroxidation. Analysis of the content of hydroxycinnamic acids of the pear, apple, plum and peach extracts measured after hydrolysis with sodium hydroxide showed that caffeic acid, p-coumaric and ferulic acids were the principal hydroxycinnamic acids present. Although the hydroxycinnamic acids and naringin do not contribute to the inhibition of lipid peroxidation by fruit extracts, they were able to inhibit deoxyribose degradation by 30% suggesting ability to weakly scavenge hydroxyl radicals (OH). Nevertheless, extracts of herbs and spices are increasingly of interest in the food industry because they retard oxidative degradation to lipids.     

PHYSICAL CHARACTERISTICS AND ANTIOXIDANT ACTIVITIES OF ORGANIC GRAPES

Studies on antioxidative activities of fruits have focused mainly on grapes, which have been reported to inhibit oxidation of human low‐density lipoprotein (LDL) at a level comparable to wine. With regard to consumer attitude on the health benefits of the product, organic grapes were selected for study. Organic grapes of Vitis vinifera origin var. Semillon, Columbard, Cabernet sauvignon, Merlot, Grenache and Carignan produced under the control of International Nutrition and Agriculture Certification Company in Kemalpasa/Ulucak were studied. The order of grape varieties concerning grape cluster, stem and number (100) values from the highest to the lowest was determined as: Semillon > Merlot > Cabernet sauvignon > Carignan > Columbard > Grenache. Positive correlation was determined between antioxidant activities (AOA) and total phenols (r = 0.845; P = 0.034). The highest AOA were determined in Merlot (86.55%) and Cabernet sauvignon (83.60%) varieties. Considering LDL, low‐density lipoprotein‐diene values for Cabernet sauvignon and Merlot varieties were 82.73 and 65.48%, respectively. The values of low‐density lipoprotein‐malondialdehyde were different, with the highest percentage found for Semillon (80%). The highest value of total phenols was found in Merlot (4,200 mg/L gallic acid equivalents) variety. Evaluating all analyzed parameters, principal component analysis results demonstrated the similarities between Carignan and Grenache, between Merlot and Cabernet sauvignon and between Columbard and Semillon grape varieties.     

ANTIOXIDANT PROPERTIES OF LENTINUS EDODES AND AGARICUS BLAZEI EXTRACTS

ABSTRACT

This work aimed to evaluate the antioxidant activity of Lentinus edodes and Agaricus blazei mushrooms, as well as to measure the content of total phenolic compounds of mushroom extracts and verify the oxidative stability of soybean oil added with mushroom extracts that showed higher antioxidant activity according to the methods of the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH^•) free radical scavenging and the β‐carotene/linoleic acid system. According to the DPPH^• method, the maximum antioxidant activity for L. edodes and A. blazei methanol extracts was 92.84 and 95.10%, respectively. For the β‐carotene/linoleic acid system, the highest values of antioxidant activity were 93.06% for L. edodes and 78.96% for A. blazei. The content of total phenolic compounds ranged from 7.21 to 128.44 and 26.67 to 134.67 mg gallic acid equivalent/g for L. edodes and A. blazei, respectively. The oxidative stability values provided by the Rancimat method indicated that the two varieties presented similar induction period of 19.85 h.

PRACTICAL APPLICATIONS

Mushrooms present high content of antioxidant compounds that are capable of reducing the harmful effects of free radicals. Among the antioxidants present in mushrooms, phenolic compounds stand out as phenolic acids, flavonoids and tocopherols. To decrease or prevent lipid oxidation, synthetic antioxidants are used as food additives. Nevertheless, studies have revealed that these compounds are likely to pose risks to human health. The concern regarding the safety of synthetic antioxidants has motivated the search of natural antioxidants that can substitute them totally or partially.

     

酶法降解小麦面筋蛋白制备抗氧化产物的研究

采用12种不同来源、不同性质的蛋白酶对小麦面筋蛋白进行酶解改造，通过考察水解液体外抗氧化活性、酶解蛋白的水解度和回收率等指标，筛选最适降解小麦蛋白的蛋白酶。结果表明：木瓜蛋白酶（精）效果最佳，其酶解蛋白含量为2．81％，回收率为76，60％，水解度为58．22％，经稀释5倍后的DPPH自由基的清除率为76．5％，还原力为3，00％。