The effect of solar radiation on flavonoid biosynthesis was studied in bilberry ( Vaccinium myrtillus L.) leaves. Expression of flavonoid pathway genes of bilberry was studied in the upper leaves of bilberry, exposed to direct sunlight, in the shaded leaves growing lower in the same plants and in fruits. Bilberry-specific digoxigenin-dUTP-labeled cDNA fragments of five genes from the general phenylpropanoid pathway coding phenylalanine ammonia-lyase and from the flavonoid pathway coding chalcone synthase, flavanone 3-hydroxylase, dihydroflavonol 4-reductase, and anthocyanidin synthase were used as probes in gene expression analysis. Anthocyanins, catechins, proanthocyanidins, flavonols and hydroxycinnamic acids from the leaves and fruits were identified and quantified using high-performance liquid chromatography combined with a diode array detector. An increase in the expression of the studied flavonoid pathway genes was observed in leaves growing under direct sun exposure. Also, the concentrations of anthocyanins, catechins, flavonols and hydroxycinnamic acids were higher in the leaves exposed to direct sunlight. However, the concentration of polymeric procyanidins was lower in sun-exposed leaves, whereas that of prodelphinidins was slightly increased. The results give further support for the protective role of flavonoids and hydroxy cinnamic acids against high solar radiation in plants. Also, the roles of different flavonoid compounds as a defense against stress caused by sun exposure is discussed.
The experience gained in the aftermath of serious radiation accidents shows that forests are an important source of external and internal exposure of the affected population. This paper presents the results of an assessment of the major radiological consequences for forests of Russia, most heavily contaminated after the Chernobyl nuclear power plant (ChNPP) accident. Illustrated in the Novozybkovsky district of the Russian Federation, the significance of different forest exposure pathways is estimated and the doses resulting from forest pathways are compared with the doses from agricultural products. It has been found that the contribution of mushrooms and berries to the internal doses of the population, relative to the doses from agricultural products, varied from 10-15% in 1987 to 40-45% in 1996. The results indicate large differences in internal exposure of members of the "critical groups" and "normal population", increasing with time after deposition. Data are presented that give information on the contribution of forests to the collective doses of inhabitants of the area under consideration. It has been shown that for 10 years after the accident (1987-1996), the contribution of forest products to the collective dose of the rural population living in contaminated forests of the Novozybkovsky district, amounts to about 20% (213 person Sv) of the total collective dose of internal and external exposures. However, a potential impact of these products including the dose from exported products is much higher and might reach 659 person Sv. It has been found that in the long-term after the ChNPP accident, serious attention should be given to forest countermeasures, and restoration strategies should be selected on the basis of a combined analysis of the effectiveness of forest and agricultural countermeasures.
An isotope dilution method based on solvent extraction followed by GC-MS analysis was developed and used to determine aniline in vegetable and fruit samples collected from the Canadian total diet study. Aniline was not detected in any of the 23 vegetable samples from the 2005 total diet study at a method detection limit of 0.01 mg kg(-1). Among the 16 fruit samples, it was detected only in apple samples, with an average concentration of 0.278 mg kg(-1). Aniline was not detected in apple samples collected in the 2002, 2003, 2006 or 2007 total diet studies, but it was detected in the apple samples collected from the 2001 and 2004 studies, at concentrations of 0.085 and 0.468 mg kg(-1), respectively. The average aniline concentration for the 2001, 2004 and 2005 apple samples was 0.277 mg kg(-1). Good repeatability of the method was observed with replicate analysis of apple samples, with relative standard deviations (RSD) ranging 3.8-21% and an average of 11%.
It has been estimated that up to one-third of patients with diabetes mellitus use some form of complementary and alternative medicine. Momordica charantia (bitter melon) is a popular fruit used for the treatment of diabetes and related conditions amongst the indigenous populations of Asia, South America, India and East Africa. Abundant pre-clinical studies have documented the anti-diabetic and hypoglycaemic effects of M. charantia through various postulated mechanisms. However, clinical trial data with human subjects are limited and flawed by poor study design and low statistical power. The present article reviews the clinical data regarding the anti-diabetic potentials of M. charantia and calls for better-designed clinical trials to further elucidate its possible therapeutic effects.
In Finland, berries are part of the traditional diet significantly contributing to the intake of flavonoids and other phenolic compounds. Compositional data on phenolic compounds in berries has been rapidly accumulating and included in the national food composition database. Among the different bioactive substances in berries, phenolic compounds including flavonoids, tannins, and phenolic acids have received considerable interest due to their effects in food and health. A great amount of in vitro evidence exists showing that berry phenolics are powerful antioxidants. However, the antioxidant effect of berry phenolics is strongly dependent on the choice of berry raw material, as the antioxidant activity differs between the different phenolic constituents, including anthocyanins, ellagitannins, and proanthocyanidins. In foods, the antioxidant effect is also influenced by the structure of food. Tannin-containing berries exhibit antimicrobial properties against pathogenic bacteria, thus offering many new applications for food industry. Much of the interest in berry phenolics has focused on cranberries and both cultivated and wild blueberries, although also other berries including black currants, cloudberries, lingonberries, and red raspberries possess promising bioactivities that may have relevance to human health. Antioxidant activity of berry phenolics, in addition to other mechanisms, may contribute to human health, but the possible relationship remains yet to be scientifically substantiated.
Selection, collection and preparation of 35 plant species used by traditional healers in the boreal regions of Canada for treatment of the symptoms of diabetes were supported empirically by antioxidant activity of the plants. Because antioxidants fluctuate with growth parameters and environmental factors, these remedies were evaluated in relation to the affect of plant part, life form and growing condition on the level of activity. The parts used here more frequently as medicines were roots and bark. Activity (IC(50)) of the bark extracts used medicinally averaged to 21.38+/-3.84 ppm while root extracts used medicinally had an IC(50) of 185.11+/-32.18 ppm in a free radical DPPH assay. In contrast the analysis of extracts of overall parts (medicinal or not) in these species found leaves and bark to have the least activity (112.22+/-30.63 ppm and 123.02+/-21.13 ppm, respectively). The highest activity was found in tree extracts (24.88+/-3.32 ppm) as compared to herbs and shrubs, and increased activity was found in plant extracts from growing conditions of decreased water/fertility. The antioxidant activity of these traditional plant remedies have the potential to be partially deduced through environment signals interpreted by the traditional herbalist.
Lonicera caerulea is a species of bush native to the Kamchatka Peninsula (Russian Far East) whose berries have been extensively studied due to their potential high antioxidant activity. The aim of our work was to investigate the in vivo effects of the antioxidant action of Lonicera caerulea berry extracts on the dynamics of experimentally-induced tumors. Our data showed that aqueous Lonicera caerulaea extracts reduced the tumor volume when administered continuously during the tumor growth and development stages, but augmented the tumor growth when the administration of extracts started three weeks before tumor grafting. Prolonged administration of Lonicera caerulaea berry extracts induced the antioxidant defense mechanism in the tumor tissues, while surprisingly amplifying the peripheral oxidative stress.
The Danish Fitness and Nutrition Council has evaluated the basis for recommendations on the intake of antioxidants and has found limited basis for increasing the recommended intake levels for the antioxidants vitamin C and E. Evidence was insufficient to support recommendations for polyphenol or carotenoid supplementation. Supplementation with high doses of vitamin E and beta-carotene may present a health risk. A high intake of fruit and vegetables is associated with a reduced risk of lifestyle diseases, but there is no evidence that this association is due to an antioxidant effect.
Comment In: Ugeskr Laeger. 2006 Oct 9;168(41):3537; author reply 353717066533
INTRODUCTION: The aim of the present study was to quantify the impact of different dietary factors on the mortality from ischaemic heart disease in Denmark. METHODS: Relative risks and knowledge on the distribution of different dietary factors were used to estimate etiological fractions. RESULTS: It is estimated that an intake of fruit and vegetables and saturated fat as recommended would prevent 12 and 22%, respectively, of deaths from ischaemic heart disease in Denmark. An intake of fish among those at high risk for ischaemic heart disease, would lead to a 26% lower mortality, while alcohol intake among abstainers would have no significant quantitative effect. DISCUSSION: These results suggest that changes in dietary habits according to current recommendations would have an impact on public health in Denmark.