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Masoud Hashemi - One of the best experts on this subject based on the ideXlab platform.
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Accumulation of silymarin in milk thistle seeds under drought stress
Planta, 2015Co-Authors: Reza Keshavarz Afshar, Mohammad Reza Chaichi, Mahya Ansari Jovini, Emad Jahanzad, Masoud HashemiAbstract:Main conclusion According to the results obtained in this study, drought stress can enhance the accumulation of silymarin in milk thistle seeds. Moreover, under drought stress, the share of silybin increased which possess the greatest degree of biological activity among the silymarin components. Silymarin, an isomeric mixture of flavonolignans found in milk thistle ( Silybum marianum (L.) Gaertn) seeds, has been used for its hepatoprotective effects for more than 2,000 years. Biosynthesis and accumulation of active substances like silymarin in plant tissues highly interacts with the environmental conditions. Effects of moderate and severe drought stress (based on soil moisture depletion) on silymarin content and composition in milk thistle seeds were evaluated in a field study. Averaged across treatments, milk thistle seeds contained 19.3 g kg^−1 silymarin. Drought stress enhanced silymarin accumulation in milk thistle seeds. Plants grown under moderate and severe drought stress treatments contained 4 and 17 % greater silymarin than those grown in well-watered condition, respectively. Greater content of sylimarin in stressed plants was attributed to more contents of silybin, isosilybin and silychristin, while silydianin content was lower under drought condition. According to the results obtained in this study, drought stress enhanced accumulation of silymarin in milk thistle seeds and improved its quality by increasing the share of silybin, which possess the greatest degree of biological activity among the silymarin components.
Jitka Ulrichova - One of the best experts on this subject based on the ideXlab platform.
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A pilot study of the UVA-photoprotective potential of dehydrosilybin, isosilybin, silychristin, and silydianin on human dermal fibroblasts
Archives of Dermatological Research, 2019Co-Authors: Alena Rajnochová Svobodová, David Biedermann, Jitka Ulrichova, Eva Gabrielová, Bohumil Zálešák, Jitka VostalovaAbstract:The exposure of naked unprotected skin to solar radiation may result in numerous acute and chronic undesirable effects. Evidence suggests that silymarin, a standardized extract from Silybum marianum (L.) Gaertn. seeds, and its major component silybin suppress UVB-induced skin damage. Here, we aimed to investigate the UVA-protective effects of silymarinʼs less abundant flavonolignans, specifically isosilybin (ISB), silychristin (SC), silydianin (SD), and 2,3-dehydrosilybin (DHSB). Normal human dermal fibroblasts (NHDF) pre-treated for 1 h with flavonolignans were then exposed to UVA light using a solar simulator. Their effects on reactive oxygen species (ROS), carbonylated proteins and glutathione (GSH) level, caspase-3 activity, single-strand breaks’ (SSBs) formation and protein level of matrix metalloproteinase-1 (MMP-1), heme oxygenase-1 (HO-1), and heat shock protein (HSP70) were evaluated. The most pronounced preventative potential was found for DHSB, a minor component of silymarin, and SC, the second most abundant flavonolignan in silymarin. They had significant effects on most of the studied parameters. Meanwhile, a photoprotective effect of SC was mostly found at double the concentration of DHSB. ISB and SD protected against GSH depletion, the generation of ROS, carbonylated proteins and SSBs, and caspase-3 activation, but had no significant effect on MMP-1, HO-1, or HSP70. In summary, DHSB and to a lesser extent other silymarin flavonolignans are potent UVA-protective compounds. However, due to the in vitro phototoxic potential of DHSB published elsewhere, further studies are needed to exclude phototoxicity for humans as well as to confirm our results on human skin ex vivo and in vivo.
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Skin Protective Activity of Silymarin and its Flavonolignans.
Molecules, 2019Co-Authors: Jitka Vostalova, Eva Tinková, David Biedermann, Jitka Ulrichova, Pavel Kosina, Alena Rajnochova SvobodovaAbstract:Silybum marianum (L.) is a medicinal plant traditionally used in treatment of liver disorders. In last decades, silymarin (SM), a standardized extract from S. marianum seeds has been studied for its dermatological application, namely for UVB-protective properties. However, information on SM and its polyphenols effect on activity of enzymes participating in the (photo)aging process is limited. Therefore, evaluation of SM and its flavonolignans potential to inhibit collagenase, elastase, and hyaluronidase in tube tests was the goal of this study. The antioxidant and UV screening properties of SM and its flavonolignans silybin, isosilybin, silydianin, silychristin and 2,3-dehydrosilybin (DHSB) were also evaluated by a DPPH assay and spectrophotometrical measurement. DHSB showed the highest ability to scavenge DPPH radical and also revealed the highest UVA protection factor (PF-UVA) that corresponds with its absorption spectrum. SM and studied flavonolignans were found to exhibit anti-collagenase and anti-elastase activity. The most potent flavonolignan was DHSB. None of studied flavonolignans or SM showed anti-hyaluronidase activity. Our results suggest that SM and its flavonolignans may be useful agents for skin protection against the harmful effects of full-spectrum solar radiation including slowing down skin (photo)aging.
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Biotransformation of silymarin flavonolignans in human hepatocytes
Journal of the International Society of Antioxidants in Nutrition & Health, 2016Co-Authors: Jitka Ulrichova, David Biedermann, Barbora Papoušková, Martina Zatloukalova, Jan Vacek, Jiří VrbaAbstract:Silymarin, an extract from the seeds of Silybum marianum (milk thistle), is widely used in human medicine due to its antioxidant and hepatoprotective effects1. Silymarin consists primarily of a mixture of flavonolignans, which belong among phenolic compounds. To date, the biotransformation of the main flavonolignan silybin has only been investigated in more detail2. This study therefore examined the metabolic profiles of minor silymarin flavonolignans in human hepatocytes. We included in our experiments silybin, silychristin, silydianin, and their 2,3-dehydroderivatives, i.e. dehydrosilybin, dehydrosilychristin and dehydrosilydianin. Suspensions of human hepatocytes were incubated for up to 2 hrs with the tested compounds, and the cells and cell supernatants were analyzed using high-performance liquid chromatography/mass spectrometry method. We found that silybin, dehydrosilybin, silychristin and dehydrosilychristin were metabolized by sulfation or glucuronidation. In contrast, silydianin and dehydrosilydianin appeared to undergo reduction (i.e. hydrogenation) and/or glucuronidation. Moreover, dehydrosilydianin was the only compound which underwent the cycle fragmentation. We conclude that silymarin flavonolignans and 2,3-dehydro-flavonolignans are primarily metabolized by phase II conjugation enzymes in human hepatocytes.
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flavonolignan 2 3 dehydroderivatives preparation antiradical and cytoprotective activity
Free Radical Biology and Medicine, 2016Co-Authors: Michaela Pyszkova, David Biedermann, Jitka Ulrichova, Jiří Vrba, Michal Biler, Kateřina Valentova, Marek Kuzma, Romana Sokolova, Milos Mojovic, Ana PopovicbijelicAbstract:Abstract The protective constituents of silymarin, an extract from Silybum marianum fruits, have been extensively studied in terms of their antioxidant and hepatoprotective activities. Here, we explore the electron-donor properties of the major silymarin flavonolignans. Silybin (SB), silychristin (SCH), silydianin (SD) and their respective 2,3-dehydroderivatives (DHSB, DHSCH and DHSD) were oxidized electrochemically and their antiradical/antioxidant properties were investigated. Namely, Folin–Ciocalteau reduction, DPPH and ABTS+ radical scavenging, inhibition of microsomal lipid peroxidation and cytoprotective effects against tert-butyl hydroperoxide-induced damage to a human hepatocellular carcinoma HepG2 cell line were evaluated. Due to the presence of the highly reactive C3-OH group and the C-2,3 double bond (ring C) allowing electron delocalization across the whole structure in the 2,3-dehydroderivatives, these compounds are much more easily oxidized than the corresponding flavonolignans SB, SCH and SD. This finding was unequivocally confirmed not only by experimental approaches, but also by density functional theory (DFT) calculations. The hierarchy in terms of ability to undergo electrochemical oxidation (DHSCH~DHSD>DHSB > > SCH/SD>SB) was consistent with their antiradical activities, mainly DPPH scavenging, as well as in vitro cytoprotection of HepG2 cells. The results are discussed in the context of the antioxidant vs. prooxidant activities of flavonolignans and molecular interactions in complex biological systems.
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primary cultures of human hepatocytes as a tool in cytotoxicity studies cell protection against model toxins by flavonolignans obtained from silybum marianum
Toxicology Letters, 2003Co-Authors: Zdeněk Dvořak, Pavel Kosina, Daniela Walterova, Vilim Simanek, Petr Bachleda, Jitka UlrichovaAbstract:Abstract The aim of this study was to evaluate the cytoprotective effects upon primary human hepatocytes of silymarin extract and its main flavonolignans following exposure to the cytotoxic actions of model toxins. The conditions for the hepatocyte intoxication were optimised for allyl alcohol, carbon tetrachloride, d -galactosamine and paracetamol. Silymarin extract, silychristin and silydianin did not exert cytotoxicity (10–100 μM), whereas silybin and isosilybin at higher concentrations and after longer incubation periods were cytotoxic. All main flavonolignans of silymarin tested displayed concentration-dependent cytoprotection against the toxic effects of both allyl alcohol and carbon tetrachloride but neither paracetamol nor galactosamine. The best protection was achieved by silydianin and silychristin and to a lesser degree by silymarin, while silybin and isosilybin were less effective. It is concluded that these differing outcomes result from the varying abilities of the Silybum marianum substances tested to stabilize the cell membrane, exert antioxidant properties and exhibit intrinsic toxicity.
Edgar C. Clausen - One of the best experts on this subject based on the ideXlab platform.
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Extraction of Co-Products from Biomass: Example of Thermal Degradation of Silymarin Compounds in Subcritical Water
Applied Biochemistry and Biotechnology, 2009Co-Authors: Lijun Duan, Edgar C. Clausen, Sunny N. Wallace, Abigail Engelberth, Justin K. Lovelady, Jerry W. King, Danielle-julie CarrierAbstract:In an effort to increase revenues from a given feedstock, valuable co-products could be extracted prior to biochemical or thermochemical conversion with subcritical water. Although subcritical water shows significant promise in replacing organic solvents as an extraction solvent, compound degradation has been observed at elevated extraction temperatures. First order thermal degradation kinetics from a model system, silymarin extracted from Silybum marianum , in water at pH 5.1 and 100, 120, 140, and 160 °C were investigated. Water pressure was maintained slightly above its vapor pressure. Silymarin is a mixture of taxifolin, silichristin, Silidianin, silibinin, and isosilibinin. The degradation rate constants ranged from 0.0104 min^−1 at 100 °C for silichristin to a maximum of 0.0840 min^−1 at 160 °C for silybin B. Half-lives, calculated from the rate constants, ranged from a low of 6.2 min at 160 °C to a high of 58.3 min at 100 °C, both for silichristin. The respective activation energies for the compounds ranged from 37.2 kJ/gmole for Silidianin to 45.2 kJ/gmole for silichristin. In extracting the silymarin with pure ethanol at 140 °C, no degradation was observed. However, when extracting with ethanol/water mixtures at and 140 °C, degradation increased exponentially as the concentration of water increased.
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pretreatment of milk thistle seed to increase the silymarin yield an alternative to petroleum ether defatting
Bioresource Technology, 2008Co-Authors: Senthil Subramaniam, Katherine Vaughn, Danielle-julie Carrier, Edgar C. ClausenAbstract:Abstract Milk thistle ( Silybum marianum L.) seed meal is extracted for the flavonolignans, silychristin, silydianin, silybinin A, silybinin B, isosilybinin A and isosilybinin B, which are collectively known as the silymarin complex. To obtain the flavonolignans, the meal is usually treated with successive washes of petroleum ether to remove the lipids, followed by extraction of the flavonolignans with ethanol. This work examines the possible replacement of petroleum ether and ethanol by water or other aqueous solutions in these processes. To replace petroleum ether, pretreatments with 1.2% NaOH (w/w), 1.5% H 2 SO 4 (w/w), 2% NaHCO 3 (w/w), 0.14% cellulase and water were investigated. Of these pretreatments, 1.5% H 2 SO 4 and water produced similar flavonolignan yields as petroleum ether. Results established that pretreating the milk thistle seed meal with 1.5% H 2 SO 4 (w/w) at 50 °C for 18 h could replace the petroleum ether pretreatment. In addition, it was shown that similar amounts of flavonolignan could be recovered with a 1.5% H 2 SO 4 /water (100 °C) extraction as with a petroleum ether/ethanol extraction. Although cellulase pretreatment was not examined extensively, significant advances in cellulase effectiveness and cost have occurred in the past few years by companies such as Genencor International and Novozymes. These advances should help to make enzyme use for cellulose conversion, as well as extraction pretreatment, technically and economically feasible.
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Milk thistle extracts inhibit the oxidation of low-density lipoprotein (LDL) and subsequent scavenger receptor-dependent monocyte adhesion.
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Sunny N. Wallace, Katherine Vaughn, Edgar C. Clausen, Bradford W. Stewart, Tito Viswanathan, Shanmugam Nagarajan, Danielle-julie CarrierAbstract:Silymarin encompasses a group of flavonolignans that are extracted from Silybum marianum (Asteraceae) fruits. The silymarins have previously been reported to lower low-density lipoprotein (LDL) levels associated with high-fat diets. The present study reports the efficacy of the silymarins in inhibiting oxidized low-density lipoprotein (oxLDL) generation and subsequent scavenger receptor (SR) mediated monocyte adherence to oxLDL. The flavonolignans that comprise silymarin include silichristin (SC), Silidianin (SD), silibinin (SBN), and isosilibinin (IS). These flavonolignans (300 µM) lowered oxLDL generation, measured by the thiobarbituric acid-reacting substances (TBARS) assay, by 60.0, 28.1, 60.0, and 30.1%, respectively. SBN treatment of LDL in the presence of copper sulfate (CuSO4) resulted in a significant dose-dependent inhibition of monocyte adhesion. Inhibition was paralleled by a decrease in binding of anti-oxLDL antibodies recognized by U937 monocyte Fc gamma receptors (FcγR). These results showe...
John S Markowitz - One of the best experts on this subject based on the ideXlab platform.
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an assessment of pharmacokinetics and antioxidant activity of free silymarin flavonolignans in healthy volunteers a dose escalation study
Drug Metabolism and Disposition, 2013Co-Authors: Bryan J Brinda, Kenneth D Chavin, Hilary J Bernstein, Kennerly S Patrick, John S MarkowitzAbstract:Milk thistle (Silybum marianum) extracts, one of the most widely used dietary supplements, contain a mixture of six major flavonolignans (silybin A, silybin B, isosilybin A, isosilybin B, silychristin, and silydianin) and other components. However, the pharmacokinetics of the free individual flavonolignans have been only partially investigated in humans. Furthermore, antioxidant effects of the extract, which may underlie the basis of many therapeutic effects, have not been thoroughly assessed. The present study evaluated the pharmacokinetics of the six major flavonolignans in healthy volunteers receiving single doses of either one (175 mg), two (350 mg), or three (525 mg) milk thistle capsule(s) on three separate study visits. Additionally, the steady-state pharmacokinetic parameters were determined after the subjects were administered one capsule three times daily for 28 consecutive days. Our results demonstrated that all six flavonolignans were rapidly absorbed and eliminated. In order of abundance, the exposure to free flavonolignans was greatest for silybin A followed by silybin B, isosilybin B, isosilybin A, silychristin, and silydianin. The systemic exposure to these compounds appeared linear and dose proportional. The disposition of flavonolignans was stereoselective, as evidenced by the apparent clearance of silybin B, which was significantly greater than silybin A, whereas the apparent clearance of isosilybin B was significantly lower than isosilybin A. The concentrations of urinary 8-epi-prostaglandin F2α, a commonly used biomarker of oxidative status in humans, were considerably decreased in study subjects after a 28-day exposure to the extract (1.3 ± 0.9 versus 0.8 ± 0.9 ng/mg creatinine) but failed to reach statistical significance (P = 0.076).
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a sensitive lc ms ms assay for the simultaneous analysis of the major active components of silymarin in human plasma
Journal of Chromatography B, 2012Co-Authors: Bryan J Brinda, John S MarkowitzAbstract:Abstract Silymarin, an extract of crushed achenes of the milk thistle plant Silybum marianum is a multi-constituent mixture, 70–80% of which consists of a complex assortment containing the flavonolignans silybin A and B, isosilybin A and B, silydianin, and silychristin, and the flavonoid taxifolin. To date, numerous pharmacological actions of the silymarin extract have been documented in the biomedical literature, including hepatoprotective, anti-inflammatory, anti-tumor, and anti-fibrotic activities. The present study describes a novel liquid chromatographic–tandem mass spectrometric method for simultaneous analysis of silychristin, silydianin, silybin A and silybin B, isosilybin A and isosilybin B, and taxifolin in human plasma employing liquid–liquid extraction. This assay provides excellent resolution of the individual silymarin constituents via utilization of a 100 A 250 mm × 2 mm, 5 μm C18 column with the mobile phase consisting of 51% methanol, 0.1% formic acid, and 10 mM ammonium acetate. The lower limit of quantification was 2 ng/ml for each constituent. Calibration curves were linear over the range from 2 ng/ml to 100 ng/ml for all analytes (r2 > 0.99). The intra- and inter-day accuracies were 91–106.5% and 95.1–111.9%, respectively. The intra- and inter-day precision was within 10.5%. Additionally, recovery, stability, and matrix effects were fully validated as well. This method was successfully applied to human plasma samples from subjects treated with the milk thistle extract Legalon®.
Reza Keshavarz Afshar - One of the best experts on this subject based on the ideXlab platform.
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Accumulation of silymarin in milk thistle seeds under drought stress
Planta, 2015Co-Authors: Reza Keshavarz Afshar, Mohammad Reza Chaichi, Mahya Ansari Jovini, Emad Jahanzad, Masoud HashemiAbstract:Main conclusion According to the results obtained in this study, drought stress can enhance the accumulation of silymarin in milk thistle seeds. Moreover, under drought stress, the share of silybin increased which possess the greatest degree of biological activity among the silymarin components. Silymarin, an isomeric mixture of flavonolignans found in milk thistle ( Silybum marianum (L.) Gaertn) seeds, has been used for its hepatoprotective effects for more than 2,000 years. Biosynthesis and accumulation of active substances like silymarin in plant tissues highly interacts with the environmental conditions. Effects of moderate and severe drought stress (based on soil moisture depletion) on silymarin content and composition in milk thistle seeds were evaluated in a field study. Averaged across treatments, milk thistle seeds contained 19.3 g kg^−1 silymarin. Drought stress enhanced silymarin accumulation in milk thistle seeds. Plants grown under moderate and severe drought stress treatments contained 4 and 17 % greater silymarin than those grown in well-watered condition, respectively. Greater content of sylimarin in stressed plants was attributed to more contents of silybin, isosilybin and silychristin, while silydianin content was lower under drought condition. According to the results obtained in this study, drought stress enhanced accumulation of silymarin in milk thistle seeds and improved its quality by increasing the share of silybin, which possess the greatest degree of biological activity among the silymarin components.