TY - JOUR A1 - Shi, Jiang A1 - Xie, Dongchao A1 - Qi, Dandan A1 - Peng, Qunhua A1 - Chen, Zongmao A1 - Schreiner, Monika A1 - Lin, Zhi A1 - Baldermann, Susanne T1 - Methyl jasmonate-induced changes of flavor profiles during the processing of Green, Oolong, and Black Tea JF - Frontiers in plant science N2 - Tea aroma is one of the most important factors affecting the character and quality of tea. Here we describe the practical application of methyl jasmonate (MeJA) to improve the aroma quality of teas. The changes of selected metabolites during crucial tea processing steps, namely, withering, fixing and rolling, and fermentation, were analyzed. MeJA treatment of tea leaves (12, 24, 48, and 168 h) greatly promotes the aroma quality of green, oolong, and black tea products when comparing with untreated ones (0 h) and as confirmed by sensory evaluation. MeJA modulates the aroma profiles before, during, and after processing. Benzyl alcohol, benzaldehyde, 2-phenylethyl alcohol, phenylacetaldehyde, and trans-2-hexenal increased 1.07- to 3-fold in MeJA-treated fresh leaves and the first two maintained at a higher level in black tea and the last two in green tea. This correlates with a decrease in aromatic amino acids by more than twofold indicating a direct relation to tryptophan- and phenylalanine-derived volatiles. MeJA-treated oolong tea was characterized by a more pleasant aroma. Especially the terpenoids linalool and oxides, geraniol, and carvenol increased by more than twofold. KW - methyl jasmonate KW - aroma quality KW - volatile compounds KW - amino acids KW - tea processing Y1 - 2019 U6 - https://doi.org/10.3389/fpls.2019.00781 SN - 1664-462X VL - 10 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Frede, Katja A1 - Schreiner, Monika A1 - Baldermann, Susanne T1 - Light quality-induced changes of carotenoid composition in pak choi Brassica rapa ssp. chinensis N2 - Carotenoids as part of the photosystems are crucial for their assembly, light-harvesting, and photoprotection. Light of different wavelengths impacts the composition and structure of photosystems, thus offering the possibility to influence the carotenoid concentrations and composition in photosystems by illumination with specific narrow-banded light spectra. Key components involved in the regulation of gene transcription are still poorly characterized, particularly in leafy vegetables as compared to model plants. In particular, the effect of different light qualities and its connection to redox control mechanisms, which also determine the photosystem composition and structure, is not yet well understood. Furthermore, light quality effects are species-dependent, and thus, increase the need to perform research on individual vegetable species such as pak choi Brassica rapa ssp. chinensis. Here, we investigated the carotenoid concentrations and composition of pak choi sprouts grown for 6 days under blue, red, or white light emitting diodes (LEDs) as light source. After 6 days, the total carotenoid content was the highest under white and slightly reduced under blue or red LEDs. Blue, red, and white light differently affected the carotenoid composition mainly due to variations of the beta-carotene content which could be correlated to changes in the transcript levels of beta-carotene hydroxylase 1 (beta-OHASE1). Further investigations implied a redox controlled gene expression of beta-OHASE1. In addition, transcription factors related to light signaling and the circadian clock differed in their transcriptional abundance after exposure to blue and red light. RNA-Seq analysis also revealed increased transcript levels of genes encoding the outer antenna complex of photosystem II under red compared to blue light, indicating an adjustment of the photosystems to the different light qualities which possibly contributed to the alternations in the carotenoid content and composition. KW - Brassica rapa ssp. chinensis KW - beta-carotene hydroxylase KW - Carotenoids KW - LEDs KW - Light quality KW - Redox control Y1 - 2019 U6 - https://doi.org/10.1016/j.jphotobiol.2019.02.001 SN - 1011-1344 VL - 193 SP - 18 EP - 30 PB - Elsevier CY - Lausanne ER - TY - JOUR A1 - Odongo, Grace Akinyi A1 - Schlotz, Nina A1 - Baldermann, Susanne A1 - Neugart, Susanne A1 - Ngwene, Benard A1 - Schreiner, Monika A1 - Lamy, Evelyn T1 - Effects of Amaranthus cruentus L. on aflatoxin B1- and oxidative stress-induced DNA damage in human liver (HepG2) cells JF - Food bioscience N2 - Amaranth is presently an underutilized crop despite its high content of micronutrients/bioactive phytochemicals and its capacity to thrive in harsh environmental condition. The present study aimed at determining the health benefits of Amaranthus cruentus L. in terms of protection against DNA damage induced by the mycotoxin aflatoxin B1 (AFB1) and oxidative stress using comet assay. The antioxidant potential was further investigated using electron paramagnetic resonance spectroscopy (EPR) and an ARE/Nrf2 reporter gene assay in vitro in a human liver model using the HepG2 cell line. Ethanolic extracts from fresh leaves grown under controlled conditions were used and additionally analyzed for their phytochemical content using liquid chromatography-mass spectrometry (LC-MS). The extracts inhibited both AFB1- and oxidative stress-induced DNA damage in a concentration dependent way with a maximum effect of 57% and 81%, respectively. Oxidative stress triggered using ferrous sulfate was blocked by up to 38% (EPR); the potential to induce antioxidant enzymes using ARE/Nrf2-mediated gene expression was also confirmed. Based on these in vitro findings, further studies on the health-protecting effects of A. cruentus are encouraged to fully explore its health promoting potential and provide the scientific basis for encouraging its cultivation and consumption. KW - African indigenous vegetables KW - Aflatoxin B1 KW - Amaranthaceae KW - Amaranth KW - Aspergillus KW - Cancer prevention Y1 - 2018 U6 - https://doi.org/10.1016/j.fbio.2018.09.006 SN - 2212-4292 SN - 2212-4306 VL - 26 SP - 42 EP - 48 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Klopsch, Rebecca A1 - Baldermann, Susanne A1 - Hanschen, Franziska S. A1 - Voss, Alexander A1 - Rohn, Sascha A1 - Schreiner, Monika A1 - Neugart, Susanne T1 - Brassica-enriched wheat bread: Unraveling the impact of ontogeny and breadmaking on bioactive secondary plant metabolites of pak choi and kale JF - Food chemistry N2 - Consumption of Brassica vegetables is linked to health benefits, as they contain high concentrations of the following secondary plant metabolites (SPMs): glucosinolate breakdown products, carotenoids, chlorophylls, and phenolic compounds. Especially Brassica vegetables are consumed as microgreens (developed cotyledons). It was investigated how different ontogenetic stages (microgreens or leaves) of pak choi (Brassica rapa subsp. chinensis) and kale (Brassica oleracea var. sabellica) differ in their SPM concentration. The impact of breadmaking on SPMs in microgreens (7 days) and leaves (14 days) in pak choi and kale as a supplement in mixed wheat bread was assessed. In leaves, carotenoids, chlorophylls, and phenolic compounds were higher compared to those of microgreens. Breadmaking caused a decrease of SPMs. Chlorophyll degradation was observed, leading to pheophytin and pyropheophytin formation. In kale, sinapoylgentiobiose, a hydroxycinnamic acid derivative, concentration increased. Thus, leaves of Brassica species are suitable as natural ingredients for enhancing bioactive SPM concentrations in bread. KW - Ontogeny KW - Brassica KW - Glucosinolate breakdown product KW - Flavonoid KW - Carotenoid KW - Thermal processing Y1 - 2019 U6 - https://doi.org/10.1016/j.foodchem.2019.05.113 SN - 0308-8146 SN - 1873-7072 VL - 295 SP - 412 EP - 422 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Schröter, David A1 - Neugart, Susanne A1 - Schreiner, Monika A1 - Grune, Tilman A1 - Rohn, Sascha A1 - Ott, Christiane T1 - Amaranth’s 2-Caffeoylisocitric Acid—An Anti-Inflammatory Caffeic Acid Derivative That Impairs NF-κB Signaling in LPS-Challenged RAW 264.7 Macrophages JF - Nutrients N2 - For centuries, Amaranthus sp. were used as food, ornamentals, and medication. Molecular mechanisms, explaining the health beneficial properties of amaranth, are not yet understood, but have been attributed to secondary metabolites, such as phenolic compounds. One of the most abundant phenolic compounds in amaranth leaves is 2-caffeoylisocitric acid (C-IA) and regarding food occurrence, C-IA is exclusively found in various amaranth species. In the present study, the anti-inflammatory activity of C-IA, chlorogenic acid, and caffeic acid in LPS-challenged macrophages (RAW 264.7) has been investigated and cellular contents of the caffeic acid derivatives (CADs) were quantified in the cells and media. The CADs were quantified in the cell lysates in nanomolar concentrations, indicating a cellular uptake. Treatment of LPS-challenged RAW 264.7 cells with 10 µM of CADs counteracted the LPS effects and led to significantly lower mRNA and protein levels of inducible nitric oxide synthase, tumor necrosis factor alpha, and interleukin 6, by directly decreasing the translocation of the nuclear factor κB/Rel-like containing protein 65 into the nucleus. This work provides new insights into the molecular mechanisms that attribute to amaranth’s anti-inflammatory properties and highlights C-IA’s potential as a health-beneficial compound for future research. KW - inflammation KW - caffeic acid derivatives KW - RAW 264 KW - 7 macrophages KW - NF-kappa B KW - amaranth Y1 - 2019 U6 - https://doi.org/10.3390/nu11030571 SN - 2072-6643 VL - 11 IS - 3 PB - MDPI CY - Basel ER - TY - JOUR A1 - Wiesner-Reinhold, Melanie A1 - Barknowitz, Gitte A1 - Florian, Simone A1 - Mewis, Inga A1 - Schumacher, Fabian A1 - Schreiner, Monika A1 - Glatt, Hansruedi T1 - 1-Methoxy-3-indolylmethyl DNA adducts in six tissues, and blood protein adducts, in mice under pak choi diet: time course and persistence JF - Archives of toxicology : official journal of EUROTOX N2 - We previously showed that purified 1-methoxy-3-indolylmethyl (1-MIM) glucosinolate, a secondary plant metabolite in Brassica species, is mutagenic in various in vitro systems and forms DNA and protein adducts in mouse models. In the present study, we administered 1-MIM glucosinolate in a natural matrix to mice, by feeding a diet containing pak choi powder and extract. Groups of animals were killed after 1, 2, 4 and 8 days of pak choi diet, directly or, in the case of the 8-day treatment, after 0, 8 and 16 days of recovery with pak choi-free diet. DNA adducts [N-2-(1-MIM)-dG, N-6-(1-MIM)-dA] in six tissues, as well as protein adducts [tau N-(1-MIM)-His] in serum albumin (SA) and hemoglobin (Hb) were determined using UPLC-MS/MS with isotopically labeled internal standards. None of the samples from the 12 control animals under standard diet contained any 1-MIM adducts. All groups receiving pak choi diet showed DNA adducts in all six tissues (exception: lung of mice treated for a single day) as well as SA and Hb adducts. During the feeding period, all adduct levels continuously increased until day 8 (in the jejunum until day 4). During the 14-day recovery period, N-2-(1-MIM)-dG in liver, kidney, lung, jejunum, cecum and colon decreased to 52, 41, 59, 11, 7 and 2%, respectively, of the peak level. The time course of N-6-(1-MIM)-dA was similar. Immunohistochemical analyses indicated that cell turnover is a major mechanism of DNA adduct elimination in the intestine. In the same recovery period, protein adducts decreased more rapidly in SA than in Hb, to 0.7 and 37%, respectively, of the peak level, consistent with the differential turnover of these proteins. In conclusion, the pak choi diet lead to the formation of high levels of adducts in mice. Cell and protein turnover was a major mechanism of adduct elimination, at least in gut and blood. KW - 1-Methoxy-3-indolylmethyl glucosinolate KW - Neoglucobrassicin KW - DNA adducts KW - Blood protein adducts KW - Pak choi Y1 - 2019 U6 - https://doi.org/10.1007/s00204-019-02452-3 SN - 0340-5761 SN - 1432-0738 VL - 93 IS - 6 SP - 1515 EP - 1527 PB - Springer CY - Heidelberg ER -