Maria Leontowicz

Comparative content of some bioactive compounds in apples, peaches and pears and their influence on lipids and antioxidant capacity in rats

The aim of this study was to compare some bioactive compounds in apples, peaches and pears and their influence on lipids and antioxidant capacity in rats. The content of total polyphenols (g/100g) was 0.23 +/- 0.03; 0.22 +/- 0.03 and 0.68 +/- 0.1 in peeled fruits and 0.48 +/- 0.04, 0.47 +/- 0.04 and 1.2 +/- 0.12 in peels of peaches, pears and apples, respectively. Caffeic, p-coumaric and ferulic acids and the total radical-trapping antioxidative potential (TRAP) values in peeled apples and their peels were significantly higher than in peaches and pears, respectively. Contrarary, no significant differences in the content of dietary fiber among the studied fruits were found. The content of all studied indices in peels was significantly higher than peeled fruits (p < 0.05 ). A good correlation between the total polyphenols and the TRAP values was found in all fruits. Diets supplemented with apples and to a less extent with peaches and pears have improved lipid metabolism and increased the plasma antioxidant potential especially in rats fed with added cholesterol. The highest content of biologically active compounds and the best results in the experiment on rats makes apple preferable for dietary prevention of atherosclerosis and other diseases.

Comparison of the Main Bioactive Compounds and Antioxidant Activities in Garlic and White and Red Onions after Treatment Protocols

Polish garlic and white and red onions were subjected to blanching, boiling, frying, and microwaving for different periods of time, and then their bioactive compounds (polyphenols, flavonoids, flavanols, anthocyanins, tannins, and ascorbic acid) and antioxidant activities were determined. It was found that blanching and frying and then microwaving of garlic and onions did not decrease significantly the amounts of their bioactive compounds and the level of antioxidant activities ( P > 0.05). The HPLC profiles of free and soluble ester- and glycoside-bound phenolic acids showed that trans-hydroxycinnamic acids (caffeic, p-coumaric, ferulic, and sinapic) were as much as twice higher in garlic than in onions. Quercetin quantity was the highest in red onion among the studied vegetables. The electrophoretic separation of nonreduced garlic and onion proteins after boiling demonstrated their degradation in the range from 50 to 112 kDa.

Sugar beet pulp and apple pomace dietary fibers improve lipid metabolism in rats fed cholesterol

The eAect of diets supplemented with sugar beet pulp fiber (SBP, 10%) and apple pomace fiber (AP, 10%) on lipids and lipids peroxides was investigated in 60 male Wistar rats. The rats were divided into six groups of 10 and adapted to cholesterol-free or 0.3% cholesterol diets. The basal diet (BD) contained wheat meal, barley meal, wheat hulls, meat-bone meal, barley sprouts, skimmed milk, fodder yeast, mineral and vitamin mixtures. The Control group (Control) consumed BD only. To the BD were added 3 g/kg cholesterol (Chol), 100 g/kg dry sugar beet pulp fiber (SBP), both 100 g/kg sugar beet pulp fiber and 3 g/kg cholesterol (SBP+Chol), 100 g/kg apple pomace fiber (AP), both 100 g/kg apple pomace fiber and 3 g/kg cholesterol (AP+Chol). The experiment lasted 40 days. Plasma total cholesterol (TC), LDL cholesterol (LDL-C), HDL cholesterol (HDL-C), triglycerides (TG), total phospholipids (TPH), HDL phospholipids (HDL-PH), lipid peroxides (LP) and liver TC concentration were measured. Groups did not diAer before the experiment. In the Chol+SBP and the Chol+AP vs. Chol group the sugar beet pulp and apple pomace dietary fiber supplemented diet significantly (P<0.05) hindered the rise of plasma lipids: (a) TCˇ2.97 vs. 3.69 mmol/l, ˇ20% and 3.01 vs 3.69 mmol/l, ˇ18.4%, respectively; (b) LDL-C ˇ1.36 vs. 2.02 mmol/l, ˇ32.6% and 1.39 vs. 2.02 mmol/l, ˇ31.2%, respectively; (c) TGˇ0.73 vs. 0.88 mmol/l, and 0.75 vs. 0.88 mmol/l;ˇ17 andˇ14.8%, respectively, and TC in liver (17.1 vs. 24.3 mmol/g,ˇ29.6% and 17.9 v. 24.3 mmol/g,ˇ26.3%, respectively. Sugar beet and apple pomace fiber-supplemented diets significantly hindered the decrease in HDL-PH (0.79 vs. 0.63 mmol/l,ˇ25.3%, P<0.025 and 0.75 vs. 0.63 mmol/l,ˇ19%, P<0.05, respectively) and decreased the level of TPH (1.34 vs. 1.74 mmol/l,ˇ23%, P<0.005 and 1.37 vs. 1.74 mmol/l,ˇ21.3%, P<0.01, respectively). Both sugar beet pulp fiber and apple pomace fiber, in rats fed the basal diet without cholesterol, did not significantly aAect the variables measured. Neither sugar beet pulp fiber or apple pomace fiber-supplemented diets influenced the level of lipid peroxides. These results demonstrate that sugar beet pulp fiber and to a lesser degree apple pomace fiber possess hypolipidemic properties. This is more evident when sugar beet pulp fiber or apple pomace fiber are added to the diet of rats fed cholesterol. The hypolipidemic eAects of both sugar beet pulp fiber and apple pomace fiber can be attributed to their water-soluble parts. The sugar beet pulp and apple pomace fibers have no antioxidant properties. # 2000 Elsevier Science Ltd. All rights reserved.

The effects of diets, supplemented with either whole persimmon or phenol-free persimmon, on rats fed cholesterol.

The purpose of this study was to compare the hypolipidemic and antioxidant effects of two diets in rats fed cholesterol (NOC). The experiment was performed on 3 groups of growing male Wistar rats. In each group there were 12 animals and during 4 weeks they were fed different diets: the control group (CG) fed semipurified diet with 1% of NOC, and two experimental groups (EG1) and (EG2) fed the same diet fortified with 7% of whole dry persimmon and 7% of phenol-free dry persimmon, respectively. Before and after the 4 week trial period, in rats of all groups, total cholesterol (TC), LDL-C, HDL-C, tryglicerides (TG) and lipid peroxides (LP) were studied. The results of the experiment showed a statistically significant increase in plasma TC and LDL-C only in CG (P < 0.0005) and EG2 (P < 0.0025). The increase of TC and LDL-C in the EG-1 fed diet, supplemented with whole persimmon, was statistically not significant (P for both < 0.1). Only in EG1 was a statistically not significant increase in HDL-C registered (P < 0.1). The decrease in HDL-C/TC ratio in this group of rats was minimal (from 0.57 to 0.54). A significant increase of LP was found in all three groups. An increase of LP with the EG2-fed diet, supplemented with phenol-free persimmon, was equal to the increase of LP in CG. For the EG1-fed diet supplemented with whole persimmon, a statistically less significant increase of LP was found (P < 0.05 versus both EG2 and CG). The results of this experiment show that both diets fortified with 7% of whole dry persimmon and with 7% of phenol-free dry persimmon improve lipid levels. But only diet supplemented with whole persimmon exerts an antioxidant effect. Therefore, the antioxidant effect of this fruit is associated mainly with persimmon phenols and not with the persimmon fibre.

Some analytical assays for the determination of bioactivity of exotic fruits.

INTRODUCTION The consumption of new exotic fruits, with their high nutritional and sensory value, has significantly increased in the past few years. Among the tropical fruits durian (Durio zibethinus Murr.) is less known than mango (Mangifera indica L.) and avocado (Persea americana). It has been shown that durian, mango and avocado possessed high nutritional and bioactive properties, but these data were determined using different methods. In order to obtain reliable results we investigated samples of durian, mango and avocado of the same stage of ripeness and unified methods were used for determination of the antioxidant potential. As far as we know, no results of such comparative investigation of three tropical fruits (durian, mango and avocado) and the use of such tests for phytochemical control have been published. OBJECTIVE Lyophilised durian, mango and avocado samples harvested in 2008 in Thailand and Israel were investigated. METHODOLOGY The contents of crude protein, fat, carbohydrate, dietary fibre, total polyphenols, flavonoids, tannins and flavanols were determined by elemental analysis and UV spectroscopy. The presence of polyphenols (flavonoids and phenolic acids) in the investigated samples was studied by Fourier transform infrared (FT-IR) spectroscopy and three-dimensional fluorometry. Four complementary radical scavenging assays were used for antioxidant determination: ferric reducing antioxidant power (FRAP), 2, 2-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) diamonium salt (ABTS(*+)), 1-diphenyl-2-picrylhydrazyl method (DPPH) and cupric reducing antioxidant capacity (CUPRAC). Chemometrical processing was used for statistical comparison of the fruits. RESULTS All spectrometric measurements were highly correlated. The contents of total fibre, proteins and fats were significantly higher (p < 0.05) in avocado, and carbohydrates were significantly lower in avocado (p > 0.05) than in the two other fruits. The wavelength numbers of FTIR spectra for three investigated fruits were in the same range (1700-600 cm(-1)) as for catechin and gallic acid, used as standards. One main peak could be easily observed at the approximate location of ex/em 275/305 nm and the other one at ex/em 350/430 nm in the methanol polyphenol extracts of investigated fruits in three-dimensional fluorescence, in contour and cross fluorescence maps. Similarity was found between durian, mango and avocado in polyphenols (9.88 +/- 1.0, 12.06 +/- 1.3 and 10.69 +/- 1.1, mg gallic acid equivalents/g dry weight, d.w.), and in antioxidant assays such as CUPRAC (27.46 +/- 2.7, 40.45 +/- 4.1 and 36.29 +/- 3.7, microM Trolox equivalent (TE)/g d.w.) and FRAP (23.22 +/- 2.0, 34.62 +/- 3.4 and 18.47 +/- 1.9, microM TE/g d.w.), respectively. The multisample median test between all possible pairs of groups is a Tukey-HSD type comparison and denotes the different groups in a case when a pair-wise test is significant and its q statistical value is greater than the table q parameter. The multisample median test of FRAP values were chosen from the compared fruits triplets as similar or homogenous subsets durian and avocado. CONCLUSION Nutritional and bioactive values of durian are comparable with these indices in mango and avocado. These fruits contain high, comparable quantities of basic nutritional and antioxidant compounds, and possess high antioxidant potentials. All fruits show a high level of correlation between the contents of phenolic compounds and the antioxidant potential. The methods used (three-dimensional fluorescence, FTIR spectroscopy, radical scavenging assays) are suitable for bioactivity determination of these fruits. In order to receive best results, a combination of these fruits has to be included in the diet. The methods used are applicable for bioactivity determination in phytochemical analysis in general.

Antioxidative Properties of Jaffa Sweeties and Grapefruit and Their Influence on Lipid Metabolism and Plasma Antioxidative Potential in Rats

The effective substances (polyphenols, phenolic and ascorbic acids, flavonoids and dietary fibers) and antioxidative activities, using different radical-scavenging tests, were determined for Jaffa sweeties and grapefruit. The antioxidative activities comprised the contributions from polyphenols, phenolic acids, flavonoids and ascorbate components, and were well-correlated with polyphenols and flavonoids. The correlation coefficient between the polyphenols and antioxidative activity varied from 0.73 to 0.99. All applied methods showed that sweeties had higher antioxidative activity than grapefruit. Experiments on laboratory animals show that diets supplemented with sweeties, and to a lesser extent with grapefruit, increased the plasma antioxidative potential and improved the lipid metabolism, especially in the rats fed with added cholesterol. These findings provide additional characterization of the nutritional value of citrus fruits and their influence on the lipid metabolism in rats.

Nutritional and Pharmaceutical Properties of Bioactive Compounds in Organic and Conventional Growing Kiwifruit

The bioactivity of two kiwifruit’s cultivars growing under organic and conventional conditions were studied and compared. The bioactive compounds were extracted with water and ethanol using similar conditions which are applied in pharmaceutical applications and for daily fruit consumption such as tea drink. Antioxidant radical scavenging assays [ferric-reducing/antioxidant power (FRAP); cupric reducing antioxidant capacity (CUPRAC); 2, 2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS)], fourier transform infrared (FT-IR) and ultraviolet spectroscopy, two (2D-FL) and three-dimensional (3D-FL) fluorometry were used for the detection of biologically active metabolites derived from kiwifruits (total phenols, flavonoids, chlorophylls, carotenoids and ascorbic acid). The correlation between the total phenol content (TPC) and other bioactive compounds, and their total antioxidant capacities (TAC) was calculated for studied kiwifruit’s extracts. The interaction between drugs and human serum albumin (HSA) plays an important role in the distribution and metabolism of drugs. The properties of kiwifruit’s phenol extracts showed their ability to quench HSA, forming the complexes similar to the ones between the proteins and pure flavonoids such as quercetin. The cultivar ‘Bidan’ exhibited significantly higher TAC than the classic ‘Hayward’. In conclusion, for the first time ‘Bidan’ organic kiwifruit was analyzed and compared with widely consumed ‘Hayward’, using its bioactive and fluorescence properties. The influence of physiologically active kiwifruit’s compounds on human health, through our investigations in vitro and scientifically proven information, was explained. Relatively high content of bioactive compounds, high antioxidant and fluorescence properties of kiwifruit justify its use as a source of valuable antioxidants.

Bioactivity of beer and its influence on human metabolism

Extracted total phenols, flavanols and flavonoids were measured in beer samples and their quality as antioxidants was measured by two modified antioxidant methods: the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) radical cation (ABTS •+) and the β-carotene-linoleate model system (β-carotene). It was found that the antioxidant potential of beer was well correlated with flavanols and flavonoids and was slightly lower with total polyphenols (R2 values from 0.8203 to 0.9393). Forty-two male non drinkers, hypercholesterolaemic volunteers ages 43–71 after coronary bypass surgery, were randomly divided into experimental (EG) and control (CG) groups, each of 21 participants. The antiatherosclerotic diet of the EG group was supplemented for 30 consecutive days with 330 ml beer per day. Could short-term beer consumption affect not only the risk factors of coronary atherosclerosis, but also the markers of this process: plasma albumin and its antioxidant activity? For this goal, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, plasma albumin and fibrinogen, and the antioxidant activity were determined. After the trial a significant improvement in the plasma lipid levels, and an increase in the plasma antioxidant and anticoagulant activities in patients of the EG group was registered. A parallel increase in the plasma albumin concentration and its antioxidant activity was observed. In conclusion, short-term beer consumption on the basis of the bioactivity of the beverage positively affects plasma lipid levels, plasma antioxidant and anticoagulant activities. The increase in the plasma albumin concentration and its antioxidant activity could be the markers of atherosclerosis status.

Seed oils improve lipid metabolism and increase antioxidant potential in rats fed diets containing cholesterol

Abstract The goal of this investigation was to find the most valuable among four often-used seed oils for atherosclerosis preventing diets. Fatty acids, sterols, antioxidant compounds, stability and total radical-trapping antoxidative potential (TRAP) in sunflower, sunflower high oleic, rapeseed and grapeseed oils were determined. The highest stability and the highest TRAP (3.8 Rancimat 120°C, hours and 324 nmol/ml) and the lowest stability and the lowest TRAP (2.4 Rancimat 120°C, hours and 201 nmol/ml) were in rapeseed and sunflower oils, respectively. The effect of these two seed oils on lipid metabolism and antioxidant activity was investigated on 60 (divided in six diet groups of 10) male Wistar rats adapted to cholesterol-free or 1% cholesterol diets. The control group (Control) consumed basal diet (BD) only. To the BD were added 10g/100g rapeseed (Rapeseed group) or sunflower (Sunflower group) oils, 1 g/100 g cholesterol (Chol group) or both (Chol/Rapeseed group) and (Chol/Sunflower group). The experiment lasted 4 weeks. In the Chol/Rapeseed and Chol/Sunflower vs. Chol group, the oil supplemented diets significantly ( P

The influence of raw and processed garlic and onions on plasma classical and non-classical atherosclerosis indices: investigations in vitro and in vivo.

Garlic and white and red varieties of onion were subjected to processing by a variety of culinary methods, and bioactive compounds then determined. For in vivo studies, 84 male Wistar rats were randomly divided into 14 diet groups, each of six rats, including two control groups (one with no supplementation and one with cholesterol supplementation only). During the 30‐day trial, the basal diets of the other 12 groups were supplemented with 1% cholesterol and raw or processed vegetables.