Scavenging of reactive oxygen species by silibinin dihemisuccinate

Ameliorative effects of silymarin on aflatoxin B1 toxicity in weaned rabbits: impact on growth, blood profile, and oxidative stress

Natural plant extracts offer numerous health benefits for rabbits, including improved feed utilization, antimycotic and antiaflatoxigenic effect, antioxidants, immunological modulation, and growth performance. The aim of the current study was to investigate the effects of silymarin on the performance, hemato-biochemical indices, antioxidants, and villus morphology. A total of 45 Moshtohor 4 weeks old weaned male rabbits were randomly allocated into three groups (15 rabbit/each) each group with 5 replicates. The first group served as the control group feed on an infected diet by aflatoxin B1 (AFB1) 0.02 mg/kg BW, while the second and third groups received an infected diet by AFB1 (0.02 mg/kg BW) and was treated with Silymarin 20 mg/kg BW/day or 30 mg/kg BW/day, respectively. Regarding the growth performance, silymarin supplementation significantly improved the final body weight compared with the control group. Physiologically, silymarin induced high level of dose-dependent total red blood cell count, hematocrit, eosinophils, high-density lipoprotein cholesterol, superoxid dismutase, catalase activity, total antioxidant capacityand intestinal villi width and length. Moreover, silymarin significantly restricted oxidative stress indicators, malondialdehyde, Alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglyceridein rabbits treated with (AFB1). In conclusion, silymarin supplementation to AFB1 contaminated rabbit diet may mitigate the negative effect of AFB1 on the rabbit performance and health status and increase growth performance, average daily gain, immunological modulation and antioxidants and provide a theoretical basis for the application of silymarin in livestock production.

Formulation and Characterization of Silibinin Entrapped Nano-Liquid Crystals for Activity against Aβ1-42 Neurotoxicity in In-Vivo Model

Silibinin (SIL) Encapsulated Nanoliquid Crystalline (SIL-NLCs) particles were prepared to study neuroprotective effect against amyloid beta (Aβ1-42) neurotoxicity in Balb/c mice model. Theses NLCs were prepared through hot emulsification and probe sonication technique. The pharmacodynamics was investigatigated on Aβ1-42 intracerebroventricular (ICV) injected Balb/c mice. The particle size, zeta potential and drug loading were optimized to be 153 ± 2.5 nm, -21 mV, and 8.2%, respectively. Small angle X-ray (SAXS) and electron microscopy revealed to crystalline shape of SIL-NLCs. Thioflavin T (ThT) fluroscence and circular dichroism (CD) technique were employed to understand monomer inhibition effect of SIL-NLCs on Aβ1-4. In neurobehavioral studies, SIL-NLCs exhibited enhanced mitigation of memory impairment induced on by Aβ1-42 in T-maze and new object recognition test (NORT). Whereas biochemical and histopathological estimation of brain samples showed reduction in level of Aβ1-42 aggregate, acetylcholine esterase (ACHE) and reactive oxygen species (ROS). SIL-NLCs treated animal group showed higher protection against Aβ1-42 toxicity compared to free SIL and Donopezil (DPZ). Therefore SIL-NLCs promises great prospect in neurodegenerative diseases such as Alzheimer's disease.

Combined use of dasatinib and quercetin alleviates overtraining-induced deficits in learning and memory through eliminating senescent cells and reducing apoptotic cells in rat hippocampus

Excessive physical exercise (overtraining, OT) charactered by long-term and excessive training results in the damage of multiple vital tissues including hippocampus which plays a critical role in learning and memory. A combination of dasatinib (D) plus quercetin (Q) (D+Q) belongs to senolytic drugs which selectively kill senescent cells in vitro and vivo. In this study, the rats that suffered a five-week excessive swimming training were subjected to the oral administration of D+Q. D+Q alleviated the decline in exercise performance of OT rats during the swimming training, and prevented learning and memory deficits in Morris water maze, Y-maze and novel object recognition tests after excessive swimming training. Analytical results by SA-β-gal staining and western blotting showed that D+Q significantly reduced senescent cells with repressed expression of senescence-related proteins, p53 and p21, in hippocampus. Nissl and immunohistochemical staining showed that D+Q significantly attenuated neuronal loss caused by apoptosis. Interestingly, we observed elevated level of cleaved caspase 3, an apoptosis executor protein, in p21 positive hippocampus cells by D+Q treatment in immunofluorescent staining, suggesting that senescent cells were induced to apoptosis in D+Q-treated rats. The positive control drug, silibinin, showed similar protective effect against OT, but did not induce the apoptosis of senescent cells, suggesting a difference in the protective mechanisms. These results indicated that D+Q alleviates overtraining-induced deficits in learning and memory through elimination of senescent cells and reduction of apoptotic cell number.

Nanoparticles derived from naturally occurring metal chelators for theranostic applications

Metals are indispensable for the activities of all living things, from single-celled organisms to higher organisms, including humans. Beyond their intrinsic quality as metal ions, metals help creatures to maintain requisite biological processes by forming coordination complexes with endogenous ligands that are broadly distributed in nature. These types of naturally occurring chelating reactions are found through the kingdoms of life, including bacteria, plants and animals. Mimicking these naturally occurring coordination complexes with intrinsic biocompatibility may offer an opportunity to develop nanomedicine toward clinical applications. Herein, we introduce representative examples of naturally occurring coordination complexes in a selection of model organisms and highlight such bio-inspired metal-chelating nanomaterials for theranostic applications.

Free radical biology in neurological manifestations: mechanisms to therapeutics interventions

Recent advancements and growing attention about free radicals (ROS) and redox signaling enable the scientific fraternity to consider their involvement in the pathophysiology of inflammatory diseases, metabolic disorders, and neurological defects. Free radicals increase the concentration of reactive oxygen and nitrogen species in the biological system through different endogenous sources and thus increased the overall oxidative stress. An increase in oxidative stress causes cell death through different signaling mechanisms such as mitochondrial impairment, cell-cycle arrest, DNA damage response, inflammation, negative regulation of protein, and lipid peroxidation. Thus, an appropriate balance between free radicals and antioxidants becomes crucial to maintain physiological function. Since the 1brain requires high oxygen for its functioning, it is highly vulnerable to free radical generation and enhanced ROS in the brain adversely affects axonal regeneration and synaptic plasticity, which results in neuronal cell death. In addition, increased ROS in the brain alters various signaling pathways such as apoptosis, autophagy, inflammation and microglial activation, DNA damage response, and cell-cycle arrest, leading to memory and learning defects. Mounting evidence suggests the potential involvement of micro-RNAs, circular-RNAs, natural and dietary compounds, synthetic inhibitors, and heat-shock proteins as therapeutic agents to combat neurological diseases. Herein, we explain the mechanism of free radical generation and its role in mitochondrial, protein, and lipid peroxidation biology. Further, we discuss the negative role of free radicals in synaptic plasticity and axonal regeneration through the modulation of various signaling molecules and also in the involvement of free radicals in various neurological diseases and their potential therapeutic approaches. The primary cause of free radical generation is drug overdosing, industrial air pollution, toxic heavy metals, ionizing radiation, smoking, alcohol, pesticides, and ultraviolet radiation. Excessive generation of free radicals inside the cell R1Q1 increases reactive oxygen and nitrogen species, which causes oxidative damage. An increase in oxidative damage alters different cellular pathways and processes such as mitochondrial impairment, DNA damage response, cell cycle arrest, and inflammatory response, leading to pathogenesis and progression of neurodegenerative disease other neurological defects.

Severe acute respiratory syndrome coronavirus 2 ORF3a induces the expression of ACE2 in oral and pulmonary epithelial cells and the food supplement Vita Deyun® diminishes this effect

The coronavirus disease 2019 (COVID-19) pandemic has become a serious global health problem and numerous studies are currently being conducted to improve understanding of the components of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, as well as to identify solutions that mitigate the effects of COVID-19 symptoms. The nutritional supplement Vita Deyun^® is composed of silymarin, glutathione, vitamin C and selenium. Studies of its individual components have demonstrated their benefits as anti-inflammatory agents, antioxidants and enhancers of the immune response. Therefore, the present study aimed to evaluate the in vitro effects of Vita Deyun on the expression of angiotensin-converting enzyme 2 (ACE2) in diverse cell lines, as well as in the presence or absence of the SARS-CoV-2 open reading frame (ORF)3a protein. Through reverse transcription-quantitative PCR, the use of viral particles containing SARS-CoV-2 ORF3a and bioinformatics analysis via the National Center for Biotechnology Information databases, ACE2 was determined to be highly expressed in oral and skin epithelial cells, with a lower expression observed in lung cells. Notably, the expression of SARS-CoV-2 ORF3a increased the level of ACE2 expression and Vita Deyun treatment diminished this effect. In addition, Vita Deyun treatment markedly decreased interleukin-18 mRNA levels. The combination of phytonutrients in Vita Deyun may help to boost the immune system and could reduce the effects of COVID-19. Ongoing clinical studies are required to provide evidence of the efficacy of Vita Deyun.

Radioprotective Potential of Nutraceuticals and their Underlying Mechanism of Action

Radiations are an efficient treatment modality in cancer therapy. Besides the treatment effects of radiations, the ionizing radiations interact with biological systems and generate reactive oxygen species that interfere with the normal cellular process. Previous investigations of synthetic radioprotectors have shown less effectiveness, mainly owing to some limiting effects. The nutraceuticals act as efficient radioprotectors to protect the tissues from the deleterious effects of radiation. The main radioprotection mechanism of nutraceuticals is the scavenging of free radicals while other strategies are involved modulation of signaling transduction of pathways like MAPK (JNK, ERK1/2, ERK5, and P38), NF-kB, cytokines, and their protein regulatory genes expression. The current review is focused on the radioprotective effects of nutraceuticals including vitamin E, -C, organosulphur compounds, phenylpropanoids, and polysaccharides. These natural entities protect against radiation-induced DNA damage. The review mainly entails the antioxidant perspective and mechanism of action of their radioprotective activities on a molecular level, DNA repair pathway, anti-inflammation, immunomodulatory effects, the effect on cellular signaling pathways, and regeneration of hematopoietic cells.

Milk thistle (Silybum Marianum) as an antidote or a protective agent against natural or chemical toxicities: a review

Biological and chemical agents cause dangerous effects on human health via different exposing ways. Recently, herbal medicine is considered as a biological and safe treatment for toxicities. Silybum marianum (milk thistle), belongs to the Asteraceae family, possesses different effects such as hepatoprotective, cardioprotective, neuroprotective, anti-inflammatory and anti-carcinogenic activities. Several studies have demonstrated that this plant has protective properties against toxic agents. Herein, the protective effects of S. marianum and its main component, silymarin, which is the mixture of flavonolignans including silibinin, silydianin and silychristin acts against different biological (mycotoxins, snake venoms, and bacterial toxins) and chemical (metals, fluoride, pesticides, cardiotoxic, neurotoxic, hepatotoxic, and nephrotoxic agents) poisons have been summarized. This review reveals that main protective effects of milk thistle and its components are attributed to radical scavenging, anti-oxidative, chelating, anti-apoptotic properties, and regulating the inflammatory responses.

Natural Compounds as Beneficial Antioxidant Agents in Neurodegenerative Disorders: A Focus on Alzheimer's Disease

The positive role of nutrition in chronic neurodegenerative diseases (NDs) suggests that dietary interventions represent helpful tools for preventing NDs. In particular, diets enriched with natural compounds have become an increasingly attractive, non-invasive, and inexpensive option to support a healthy brain and to potentially treat NDs. Bioactive compounds found in vegetables or microalgae possess special properties able to counteract oxidative stress, which is involved as a triggering factor in neurodegeneration. Here, we briefly review the relevant experimental data on curcuminoids, silymarin, chlorogenic acid, and compounds derived from the microalga Aphanizomenon flos aquae (AFA) which have been demonstrated to possess encouraging beneficial effects on neurodegeneration, in particular on Alzheimer's disease models.

Nanotherapeutic silibinin: An insight of phytomedicine in healthcare reformation

Most of the herbal origin drugs possess water insoluble active constituents which lower the bioavailability and increase systemic clearance after administration of repeated or higher dose of drug. Silymarin is extracted from the seeds and fruits of milk thistle plant Silybum marianum which consists of main biologically active component as silibinin. However, the clinical applications of silibinin show some limitations due to low aqueous solubility, poor penetration into the epithelial cells of intestine, high metabolism and rapid systemic elimination. But nanotechnology-based drug delivery system explores great potential for phytochemicals to enhance the aqueous solubility and bioavailability of BCS class II and IV drugs, improve stability and modify the pharmacological activity. This review focuses on the therapeutic properties of silibinin and discusses the benefits, challenges and applications of silibinin nanoformulations. Such nanotherapeutic system as a regular medicine will be an attractive approach to reduce the adverse events and toxicities of current therapies.

Silymarin in non-cirrhotics with non-alcoholic steatohepatitis: A randomized, double-blind, placebo controlled trial

The botanical product silymarin, an extract of milk thistle, is commonly used by patients to treat chronic liver disease and may be a treatment for NASH due to its antioxidant properties. We aimed to assess the safety and efficacy of higher than customary doses of silymarin in non-cirrhotic patients with NASH. This exploratory randomized double-blind placebo controlled multicenter Phase II trial tested a proprietary standardized silymarin preparation (Legalon^®, Rottapharm|Madaus, Mylan) and was conducted at 5 medical centers in the United States. Eligible adult patients had liver biopsy within 12 months showing NASH without cirrhosis with NAFLD Activity Score (NAS) ≥4 per site pathologist’s assessment. Participants were randomized to Legalon^® 420 mg, 700 mg, or placebo t.i.d. for 48 weeks. The primary endpoint was histological improvement ≥2 points in NAS. Of 116 patients screened, 78 were randomized. There were no significant differences in adverse events among the treatment groups. After 48–50 weeks, 4/27 (15%) in the 700 mg dose, 5/26 (19%) participants randomized to 420 mg, and 3/25 (12%) of placebo recipients reached the primary endpoint (p = 0.79) among all randomized participants, indicating no benefit from silymarin in the intention to treat analysis Review by a central pathologist demonstrated that a substantial number of participants (49, 63%) did not meet histological entry criteria and that fibrosis stage improved most in the placebo treated group, although not significantly different from other groups. Silymarin (Legalon^®) at the higher than customary doses tested in this study is safe and well tolerated. The effect of silymarin in patients with NASH remains inconclusive due to the substantial number of patients who entered the study but did not meet entry histological criteria, the lack of a statistically significant improvement in NAS of silymarin treated patients, and the unanticipated effect of placebo on fibrosis indicate the need for additional clinical trials.

Trial Registration: clinicaltrials.gov, Identifier: NCT00680407.

Hepatoprotective effects of silymarin on CCl4-induced hepatic damage in broiler chickens model

This study was conducted to investigate the hepatoprotective effects of silymarin on CCl₄-induced oxidative stress in broiler chickens model. A total of 240 day-old broilers were divided into 4 equal groups (n = 60) composed of a control group (receiving 1 mL/Kg BW saline) and 3 groups treated with silymarin (receiving 100 mg/Kg BW silymarin), CCl₄ (receiving 1 mL/Kg BW CCl₄), and combination of silymarin + CCl₄. Results indicated that silymarin has potential to mitigate the deleterious effects of CCl₄ on protein and lipid metabolism. The protective activity of silymarin against CCl₄-mediated lipid peroxidation was demonstrated by the lower serum content of MDA, as lipid peroxidation marker. CCl₄-induced hepatotoxicity was demonstrated by the elevation of serum contents of ALP, AST, ALT, and GGT enzymes, whereas silymarin decreased serum activity of ALP and AST hepatic enzymes. The CCl₄-challenged birds revealed considerable hepatic injures characterized by moderate to severe hepatocellular degeneration around the portal vein, aggregation of inflammatory cells, granulomatosis, cytolytic necrosis, periportal space fibrosis, and sinusoidal dilatation. However, liver damages were amended by the silymarin. In line with molecular study, a remarkable down-regulation was detected in the expression of CAT, GPx, and Mn-SOD hepatic genes in CCl₄-challenged birds, whereas silymarin significantly up-regulated aforementioned genes. In general, current study showed that silymarin has potential to alleviate the adverse effects of oxidative stress in poultry farms.

Silibinin Alleviates the Learning and Memory Defects in Overtrained Rats Accompanying Reduced Neuronal Apoptosis and Senescence

Excessive physical exercise (overtraining; OT) increases oxidative stress and induces damage in multiple organs including the brain, especially the hippocampus that plays an important role in learning and memory. Silibinin, a natural flavonoid derived from milk thistle of Silybum marianum, has been reported to exert neuroprotective effect. In this study, rats were subjected to overtraining exercise, and the protective effects of silibinin were investigated in these models. Morris water maze and novel object recognition tests showed that silibinin significantly attenuated memory defects in overtrained rats. At the same time, the results of Nissl, TUNEL and SA-β-gal staining showed that silibinin reversed neuronal loss caused by apoptosis, and delayed cell senescence of the hippocampus in the overtrained rats, respectively. In addition, silibinin decreased malondialdehyde (MDA) levels which is associated with reactive oxygen species (ROS) generation. Silibinin prevented impairment of learning and memory caused by excessive physical exercise in rats, accompanied by reduced apoptosis and senescence in hippocampus cells.

Antiviral Activities of Silymarin and Derivatives

Silymarin flavonolignans are well-known agents that typically possess antioxidative, anti-inflammatory, and hepatoprotective functions. Recent studies have also documented the antiviral activities of silymarin and its derivatives against several viruses, including the flaviviruses (hepatitis C virus and dengue virus), togaviruses (Chikungunya virus and Mayaro virus), influenza virus, human immunodeficiency virus, and hepatitis B virus. This review will describe some of the latest preclinical and clinical studies detailing the antiviral profiles of silymarin and its derivatives, and discuss their relevance for antiviral drug development.

The Milk Thistle (Silybum marianum) Compound Silibinin Inhibits Cardiomyogenesis of Embryonic Stem Cells by Interfering with Angiotensin II Signaling

The milk thistle (Silybum marianum (L.) Gaertn.) compound silibinin may be an inhibitor of the angiotensin II type 1 (AT₁) receptor which is expressed in differentiating embryonic stem (ES) cells and is involved in the regulation of cardiomyogenesis. In the present study, it was demonstrated that silibinin treatment decreased the number of spontaneously contracting cardiac foci and cardiac cell areas differentiated from ES cells as well as contraction frequency and frequency of calcium (Ca²⁺) spiking. In contrast, angiotensin II (Ang II) treatment stimulated cardiomyogenesis as well as contraction and Ca²⁺ spiking frequency, which were abolished in the presence of silibinin. Intracellular Ca²⁺ transients elicited by Ang II in rat smooth muscle cells were not impaired upon silibinin treatment, excluding the possibility that the compound acted on the AT₁ receptor. Ang II treatment activated extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH₂-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) pathways in embryoid bodies which were abolished upon silibinin pretreatment. In summary, our data suggest that silibinin inhibits cardiomyogenesis of ES cells by interfering with Ang II signaling downstream of the AT₁ receptor.

Silybum marianum provides cardioprotection and limits adverse remodeling post-myocardial infarction by mitigating oxidative stress and reactive fibrosis

AIMS

Milk thistle (Silybum marianum; SM) is an herb commonly used for hepatoprotection with antioxidant and antifibrotic properties. We investigated in pigs the cardiac effects of SM intake during the acute phase of myocardial infarction (MI) and remodeling period post-MI.

METHODS

Study-1 tested the effect of SM use on the acute phase of MI. Hence, animals were distributed to a control group or to receive SM prior infarction (1.5 h ischemia). Animals were sacrificed after 2.5 h of reperfusion. Study-2 tested the effect of SM use in the cardiac remodeling phase. Accordingly, animals received for 10 d diet ± SM prior MI and followed the same regime for 3 weeks and then sacrificed. Study-3 tested the effect of SM in a non-infarcted heart; therefore, animals received for 10 d diet ± SM and then sacrificed.

RESULTS

Animals taking SM before MI showed a reduction in cardiac damage (decreased oxidative damage, ROS production and xanthine oxidase levels; preserved mitochondrial function; and increased myocardial salvage; p < 0.05) versus controls. Animals that remained on chronic SM intake post-MI improved left ventricular remodeling. This was associated with the attenuation of the TGFß1/TßRs/SMAD2/3 signaling, lower myofibroblast transdifferentiation and collagen content in the border zone (p < 0.05 vs. all other groups). Cardiac contractility improved in animals taking SM (p < 0.05 vs. post-MI-control). No changes in cardiac function or fibrosis were detected in animals on SM but without MI.

CONCLUSION

Intake of SM protects the heart against the deleterious effects of an MI and favors cardiac healing. These benefits may be attributed to the antioxidant and antifibrotic properties of SM.

Protective effects of silibinin on insulin amyloid fibrillation, cytotoxicity and mitochondrial membrane damage

A growing body of evidence suggests that secretion and assembly of insulin to amyloid fibrils reduce its efficacy in treating type II diabetes and may lead to dysfunctioning of several organs. The research presented here explores the effects of silibinin on the in vitro amyloid fibrillation and cytotoxicity of bovine insulin fibrils on SH-SY5Y human neuroblastoma cells. Interaction of the resulting structures with rat brain mitochondria was also investigated. Using a range of methods for amyloid detection we showed that insulin fibrillation was significantly inhibited by silibinin in a dose-dependent fashion. Moreover, we found that silibinin was very effective in attenuating insulin fibril-induced neuronal toxicity characterized by decrease of cell viability, the release of lactate dehydrogenase, intracellular reactive oxygen species enhancement, morphological alterations, and apoptotic cell death induction. While insulin fibrillation products showed the capacity to damage mitochondria, the resultant structures produced in the presence of silibinin were totally ineffective. Together, results demonstrate the capacity of insulin fibrils to cause SH-SY5Y cell death by inducing necrosis/apoptosis changes and suggest how silibinin may afford protection. It is concluded that elucidation of such protection may provide important insights into the development of preventive and therapeutic agents for amyloid-related diseases.

Silibinin Improves TNF-α and M30 Expression and Histological Parameters in Rat Kidneys After Hepatic Ischemia/Reperfusion

BACKGROUND

Remote kidney damage is a sequel of hepatic ischemia-reperfusion (I/R) injury. Silibinin is the main ingredient of the milk thistle plant seed extract with known antioxidant and hepatoprotective activity. Our study investigates the nephroprotective potential of intravenously administered silibinin, as a lyophilized SLB-hydoxypropyl-beta-cyclodextrin product, in hepatic I/R injury.

MATERIAL AND METHODS

63 Wistar rats were divided into three groups: Sham (virtual intervention); Control (45 min ischemia and reperfusion); and Silibinin (200 μL intravenous silibinin administration after 45 min of ischemia). Kidney tissues were collected to determine TNF-α, M30 and histopathological changes at predetermined time intervals.

RESULTS

Comparing Sham vs. Control groups, proved that hepatic I/R injury increased renal TNF-α and M30 expression. Deterioration was observed in hyperemia/filtration of renal parenchyma and tubules, cortical filtration, tubular necrosis and edema (tissue swelling index). Intravenous silibinin administration and comparison of the Control vs. Silibinin groups showed a statistically significant decrease in TNF-α levels at 240 min following I/R (p < 0.0001), and in M30 at 180 min (p = 0.03) and 240 min (p < 0.0001). Renal parameters have significantly decreased in: hyperemia/filtration of renal parenchyma at 120 min (p = 0.003), 180 min (p = 0.0001) and 240 min (p = 0.0002); hyperemia/filtration of renal tubules at 120 min (p = 0.02), 180 min (p = 0.0001) and 240 min (p = 0.0005); cortical filtration (240 min - p = 0.005); tubular necrosis (240 min - p = 0.021); and edema (240 min - p = 0.001).

CONCLUSION

Our study confirms that hepatic I/R injury causes remote renal damage while the intravenous administration of silibinin leads to statistically significant nephroprotective action.

Effects of milk thistle meal on performance, ileal bacterial enumeration, jejunal morphology and blood lipid peroxidation in laying hens fed diets with different levels of metabolizable energy

This study was conducted to evaluate the effects of different levels of milk thistle meal on performance, blood biochemical indices, ileal bacterial counts and intestinal histology in laying hens fed diets containing different levels of metabolizable energy. A total number of 200 Leghorn laying hens (Hy-Line W-36) were randomly assigned to eight experimental treatments with five cage replicates of five birds each. Dietary treatments consisted of four levels of milk thistle meal (0%, 15%, 30% and 60%) and two levels of AMEn (11.09 and 12.34 MJ/kg) fed over a period of 80 days. In vitro studies revealed that the total phenolic component of milk thistle meal was 470.64 mg gallic acid equivalent/g of the sample, and its antioxidant activity for inhibiting the 2-2-diphenyl-1-picrichydrazyl free radical and reducing ferric ions was about 21% higher than that of butylated hydroxyltoluene (p < .05). Diets containing high level of AMEn led to improved egg production (p < .05), egg weight (p < .05), egg mass (p < .01) and feed conversion ratio (p < .01). In addition, offering diets containing high energy significantly enhanced (p < .01) serum triglyceride and malondialdehyde (MDA) concentrations as well as jejunal villus height. Dietary supplementation of 3% milk thistle meal resulted in the best feed conversion ratio (p < .05), reduction of ileal Escherichia coli enumeration (p < .01) and an enhancement in the villus height-to-crypt depth ratio (p < .05). Furthermore, feeding incremental levels of this meal led to remarkable decrease in serum cholesterol, triglyceride and MDA (p < .01) concentrations while significant increase in blood high-density lipoprotein content and goblet cell numbers (p < .05). The present findings indicate that milk thistle meal with high antioxidant and antibacterial properties in laying hen diets may improve health indices and productive performance.

Intraperitoneal Administration of Silymarin Protects End Organs from Multivisceral Ischemia/Reperfusion Injury in a Rat Model

Objective

To determine whether intraperitoneal silymarin administration has favorable effects on the heart, lungs, kidney, and liver and on oxidative stress in a rat model of supraceliac aorta ischemia/reperfusion injury.

Methods

Thirty male Wistar albino rats were divided equally into three groups: sham, control, and silymarin. The control and silymarin groups underwent supraceliac aortic occlusion for 45 min, followed by a 60 min period of reperfusion under terminal anesthesia. In the silymarin group, silymarin was administered intraperitoneally during ischemia at a dose of 200 mg/kg. Rats were euthanized using terminal anesthesia, and blood was collected from the inferior vena cava for total antioxidant capacity, total oxidative status, and oxidative stress index measurement. Lungs, heart, liver and kidney tissues were histologically examined.

Results

Ischemia/reperfusion injury significantly increased histopathological damage as well as the total oxidative status and oxidative stress index levels in the blood samples. The silymarin group incurred significantly lesser damage to the lungs, liver and kidneys than the control group, while no differences were observed in the myocardium. Furthermore, the silymarin group had significantly lower total oxidative status and oxidative stress index levels than the control group.

Conclusion

Intraperitoneal administration of silymarin reduces oxidative stress and protects the liver, kidney, and lungs from acute supraceliac abdominal aorta ischemia/reperfusion injury in the rat model.

Assessment of the Antioxidant Activity of Silybum marianum Seed Extract and Its Protective Effect against DNA Oxidation, Protein Damage and Lipid Peroxidation

Antioxidant properties of ethanol extract of Silybum marianum (milk thistle) seeds was investigated. We have also investigated the protein damage activated by oxidative Fenton reaction and its prevention by Silybum marianum seed extract. Antioxidant potential of Silybum marianum seed ethanol extract was measured using different in vitro methods, such as lipid peroxidation, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing power assays. The extract significantly decreased DNA damage caused by hydroxyl radicals. Protein damage induced by hydroxyl radicals was also efficiently inhibited, which was confirmed by the presence of protein damage markers, such as protein carbonyl formation and by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The present study shows that milk thistle seeds have good DPPH free radical scavenging activity and can prevent lipid peroxidation. Therefore, Silybum marianum can be used as potentially rich source of antioxidants and food preservatives. The results suggest that the seeds may have potential beneficial health effects providing opportunities to develop value-added products.

The Anti-Cancer Effect of Polyphenols against Breast Cancer and Cancer Stem Cells: Molecular Mechanisms

The high incidence of breast cancer in developed and developing countries, and its correlation to cancer-related deaths, has prompted concerned scientists to discover novel alternatives to deal with this challenge. In this review, we will provide a brief overview of polyphenol structures and classifications, as well as on the carcinogenic process. The biology of breast cancer cells will also be discussed. The molecular mechanisms involved in the anti-cancer activities of numerous polyphenols, against a wide range of breast cancer cells, in vitro and in vivo, will be explained in detail. The interplay between autophagy and apoptosis in the anti-cancer activity of polyphenols will also be highlighted. In addition, the potential of polyphenols to target cancer stem cells (CSCs) via various mechanisms will be explained. Recently, the use of natural products as chemotherapeutics and chemopreventive drugs to overcome the side effects and resistance that arise from using chemical-based agents has garnered the attention of the scientific community. Polyphenol research is considered a promising field in the treatment and prevention of breast cancer.

Is Silybin the Best Free Radical Scavenger Compound in Silymarin?

Silymarin is a natural mixture with beneficial properties for health, specifically due to its antiradical characteristics. The major components of this mixture are silybin (SIL), silychristin (SILYC), isosilybin (ISOSIL), silydianin (SILYD), and taxifolin (TAX). In this report, the electronic properties of these substances are investigated using density functional theory calculations, mainly in order to fully understand the free radical scavenger properties of these compounds. Optimized geometries and Raman spectra are reported. These results could be experimentally useful for identifying some of the major components of the mixture. The relative abundance of deprotonated species under physiological conditions is also included. The free radical scavenger capacity is studied in relation to three mechanisms: the single electron transfer (SET), the radical adduct formation (RAF), and the hydrogen atom transfer (HAT). According to this investigation, the HAT mechanism is the most efficient mechanism for scavenging free radicals for these compounds followed by the RAF mechanism where intramolecular hydrogen bonds are formed in order to stabilize the (•)OOH free radical. A particularly important factor is that none of the compounds being studied showed an outstanding antiradical capacity performance compared to the others. In this sense, silymarin is an interesting mixture with antiradical properties and we now know that one single component should be as effective as the mixture.

Drug-Induced Liver Toxicity and Prevention by Herbal Antioxidants: An Overview

The liver is the center for drug and xenobiotic metabolism, which is influenced most with medication/xenobiotic-mediated toxic activity. Drug-induced hepatotoxicity is common and its actual frequency is hard to determine due to underreporting, difficulties in detection or diagnosis, and incomplete observation of exposure. The death rate is high, up to about 10% for drug-induced liver damage. Endorsed medications represented >50% of instances of intense liver failure in a study from the Acute Liver Failure Study Group of the patients admitted in 17 US healing facilities. Albeit different studies are accessible uncovering the mechanistic aspects of medication prompted hepatotoxicity, we are in the dilemma about the virtual story. The expanding prevalence and effectiveness of Ayurveda and natural products in the treatment of various disorders led the investigators to look into their potential in countering drug-induced liver toxicity. Several natural products have been reported to date to mitigate the drug-induced toxicity. The dietary nature and less adverse reactions of the natural products provide them an extra edge over other candidates of supplementary medication. In this paper, we have discussed the mechanism involved in drug-induced liver toxicity and the potential of herbal antioxidants as supplementary medication.

Arsenic cardiotoxicity: An overview

Arsenic, a naturally ubiquitous element, is found in foods and environment. Cardiac dysfunction is one of the major causes of morbidity and mortality in the world. Arsenic exposure is associated with various cardiopathologic effects including ischemia, arrhythmia and heart failure. Possible mechanisms of arsenic cardiotoxicity include oxidative stress, DNA fragmentation, apoptosis and functional changes of ion channels. Several evidences have shown that mitochondrial disruption, caspase activation, MAPK signaling and p53 are the pathways for arsenic induced apoptosis. Arsenic trioxide is an effective and potent antitumor agent used in patients with acute promyelocytic leukemia and produces dramatic remissions. As2O3 administration has major limitations such as T wave changes, QT prolongation and sudden death in humans. In this review, we discuss the underlying pathobiology of arsenic cardiotoxicity and provide information about cardiac health effects associated with some medicinal plants in arsenic toxicity.

Silybin and 2,3-Dehydrosilybin Flavonolignans as Free Radical Scavengers

The electronic properties of six derivatives of silybin (characterized by the absence of the 2,3 double bond) and six derivatives of 2,3-dehydrosilybin (characterized by the presence of the 2,3 double bond) have been studied by applying density functional theory to fully understand the free radical scavenger's mechanism for action and the relationship between reactivity and chemical structure. Optimized geometries, Raman spectra, and λmax values are reported, enabling us to characterize the systems. These spectra may be useful for monitoring the oxidation between silybin and 2,3-dehydrosilybin, thus providing important experimental information. The relative abundance of deprotonated species under physiological conditions is also reported. Under physiological conditions (pH 7.4), ∼70% of silybin is protonated, but 60% of 2,3-dehydrosilybin is deprotonated. The free radical scavenger capacity is analyzed in terms of two mechanisms: electron transfer and adduct formation. Deprotonated molecules are better electron donors and worse electron acceptors than non-deprotonated species. The conclusions derived from this investigation completely concur with previous experimental results. The free radical scavenging activity of 2,3-dehydrosilybin derivatives is higher than that for silybin derivatives. What was not previously considered was the importance of the deprotonated species, which is remarkable and may be important for future experiments.

Nano-silymarin provides protection against γ-radiation-induced oxidative stress in cultured human embryonic kidney cells

Radiation can produce biological damage, mainly oxidative stress, via production of free radicals, including reactive oxygen species (ROS). Nanoparticles are of interest as radioprotective agents, particularly due to their high solubility and bioavailability. Silymarin is a hepatoprotective agent but has poor oral bioavailability. Silymarin was formulated as a nanoemulsion with the aim of improving its bioavailability and therapeutic efficacy. In the present study, we evaluated self-nanoemulsifying drug delivery systems (SNEDDS) formulated with surfactants and co-surfactants. Nano-silymarin was characterized by estimating % transmittance, globule size, and polydispersity index, and by transmission electron microscopy (TEM). The nano-silymarin obtained was in the range of 3-8nm diameter. With regard to DNA damage, measured by a plasmid relaxation assay, maximum protection was obtained at 10μg/mL. Cytotoxicity of nano-silymarin to human embryonic kidney (HEK) cells was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Protective efficacy against γ-radiation was assessed by reduction in micronucleus frequency and ROS generation, using the 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) assay. Radiation-induced apoptosis was estimated by microscopic analysis and cell-cycle estimation. Nano-silymarin was radioprotective, supporting the possibility of developing new approaches to radiation protection via nanotechnology.

Silibinin potentially attenuates arsenic-induced oxidative stress mediated cardiotoxicity and dyslipidemia in rats

Cardiac dysfunction is one of the major causes of mortality and morbidity throughout the world. Chronic exposure of arsenic (As) mainly leads to cardiotoxic effect. Cardiotoxicity was induced by the sodium arsenite as the source of As (5 mg/kg BW, PO) for 4 weeks. As intoxication significantly (p < 0.05) increased the serum cardiac markers, viz. creatine kinase-MB, lactate dehydrogenase, aspartate transaminase, alanine transaminase and alkaline phosphatase, oxidative stress markers in heart, plasma total cholesterol (TC), triglycerides (TG), phospholipids (PL), free fatty acids (FFA), low density lipoprotein cholesterol, very low density lipoprotein cholesterol as well as cardiac lipid profile (TC, TG and FFA) and significantly (p < 0.05) decreased the level of serum high density lipoprotein cholesterol, cardiac PL, mitochondrial enzymes such as ICDH, SDH, MDH, α-KDH and NADH dehydrogenase, levels of enzymatic antioxidant, nonenzymatic antioxidants and membrane-bound ATPases in heart. In addition, As-intoxicated rats showed a significant (p < 0.05) up-regulation of myocardial NADPH (NOX) oxidase sub units such as NOX2 and NOX4 as well as Keap-1 and down-regulation of Nrf2 and HO-1 protein expressions. Pre-administration of silibinin (SB) (75 mg/kg BW) remarkably recovered all these altered parameters to near normalcy in As-induced cardiotoxic rat. Moreover, the light microscopic and transmission electron microscopic study further supports the protective efficacy of SB on the heart mitochondria. In conclusion, our data demonstrate that SB has a potential to extenuate the arsenic-induced cardiotoxicity and dyslipidemia in rat.

Protective effect of silymarin against cisplatin-induced ototoxicity

OBJECTIVES

Silymarin is a plant extract with strong antioxidant properties in addition to anti-inflammatory and anticarcinogenic actions. The aim of this study was to investigate the potential preventive effect of silymarin on cisplatin ototoxicity in an auditory cell line, HEI-OC1 cells.

METHODS

Cultured HEI-OC1 cells were exposed to cisplatin (30 μM) with or without pre-treatment with silymarin (50 μM). Cell viability was evaluated using MTT assay. Hoechst 33258 staining was used to identify cells undergoing apoptosis. Western blot analysis was done to evaluate whether silymarin inhibits cisplatin-induced caspase and PARP activation. Cell-cycle analysis was done by flow cytometry to investigate whether silymarin is capable of protecting cisplatin-induced cell cycle arrest.

RESULTS

Cell viability significantly increased in cells pretreated with silymarin compared with cells exposed to cisplatin alone. Pre-treatment of silymarin appeared to protect against cisplatin-induced apoptotic features on Hoechst 33258 staining. Cisplatin increased cleaved caspase-3 and PARP on Western blot analysis. However, pre-treatment with silymarin inhibited the expression of cleaved caspase-3 and PARP. Silymarin did attenuate cell cycle arrest and apoptosis in HEI-OC1 cells.

CONCLUSIONS

Our results demonstrate that silymarin treatment inhibited cisplatin-induced cytotoxicity in the auditory cell line, HEI-OC1. Silymarin may be a potential candidate drug to eliminate cisplatin induced ototoxicity.

Protective effect of silymarin on noise-induced hearing loss in Guinea pigs

Background

Hearing capability plays a principal role on human's communication. Noise-induced hearing loss (NIHL) caused by exposure to high noise levels is a serious socio-economic problem in modern societies. NIHL can either be reversible, resulting in a temporary threshold shifts (TTS) or irreversible, resulting in a permanent threshold shifts (PTS). PTS is often confirmed in the time span of between 2 - 6 weeks. NIHL may be prevented by avoidance of excessive amounts of noise or reducing the sound energy entering the inner ear using hearing protective devices. However, there are some conditions that such prevention is not possible such as noise exceeding the protective capabilities of the hearing protection device, working in military or the person does not tolerate the protection device. Thus the protective agent for preventing NIHL would be useful.

Objective

Free radical molecules and consequence oxidative stress have been shown to play a significant role in noise-induced hearing loss. Silymarin is an antioxidant flavonoid complex derived from the herb milk thistle has ability to mitigating the oxidative stress, scavenge free radicals. In the current study, we aimed to evaluate the protective effect of silymarin on noise induced hearing loss in guinea pig by auditory brain stem response.

Materials and Methods

Twenty guinea pigs randomly divided into 2 groups. The animals in the experimental group were intraperitoneally injected with 100 mg/kg/day silymarin dissolved in propylene glycol for 6 consecutive days. The control subjects were intraperitoneally injected with propylene glycol for 6 consecutive days. All animals were exposed to 4 kHz octave band noise at 120 dB SPL for 6 hours. Auditory brainstem responses (ABRs) at frequencies of 2, 4, 6, 8, 12, 16 and 20 kHz were precisely recorded before intervention and then on intervals of 0, 3, 10 and 15 days after noise exposure. Data were analyzed using repeated measures ANOVA.

Results

Threshold shifts for the experimental group at all frequencies immediately, 3, 10 and 15 days after noise exposure were significantly reduced compared to the control group (P < 0.01).

Conclusions

The findings indicate a protective effect of silymarin on temporary and permanent noise-induced hearing loss.

Autophagy, polyphenols and healthy ageing

Autophagy is a lysosomal degradation process that evolved as a starvation response in lower eukaryotes and has gained numerous functions in higher organisms. In animals, autophagy works as a central process in cellular quality control by removing waste or excess proteins and organelles. Impaired autophagy and the age-related decline of this pathway favour the pathogenesis of many diseases that occur especially at higher age such as neurodegenerative diseases and cancer. Caloric restriction (CR) promotes longevity and healthy ageing. Currently, the contributing role of autophagy in the context of CR-induced health benefits is being unravelled. Furthermore recent studies imply that the advantages from polyphenol consumption may be also connected to autophagy induction. In this review, the literature on autophagy regulation by (dietary) polyphenols such as resveratrol, catechin, quercetin, silibinin and curcumin is discussed with a focus on the underlying molecular mechanisms. Special attention is paid to the implications of age-related autophagy decline for diseases and the possibility of dietary countermeasures.

Silibinin modulates lipid homeostasis and inhibits nuclear factor kappa B activation in experimental nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is associated with increased liver-related mortality. Disturbances in hepatic lipid homeostasis trigger oxidative stress and inflammation (ie, lipotoxicity), leading to the progression of NASH. This study aimed at identifying whether silibinin may influence the molecular events of lipotoxicity in a mouse model of NASH. Eight-week-old db/db mice were fed a methionine-choline deficient (MCD) diet for 4 weeks and treated daily with silibinin (20 mg/kg intraperitoneally) or vehicle. Liver expression and enzyme activity of stearoyl-CoA desaturase-1 and acyl-CoA oxidase, and expression of liver fatty acid-binding protein were assessed. Hepatic levels of reactive oxygen species, thiobarbituric acid-reactive substances (TBARS), 3-nitrotyrosine (3-NT), inducible nitric oxide synthase (iNOS), and nuclear factor kappa B (NFkB) activities were also determined. Silibinin administration decreased serum alanine aminotransferase and improved liver steatosis, hepatocyte ballooning, and lobular inflammation in db/db mice fed an MCD diet. Gene expression and activity of stearoyl-CoA desaturase-1 were reduced in db/db mice fed an MCD diet compared with lean controls and were increased by silibinin; moreover, silibinin treatment induced the expression and activity of acyl-CoA oxidase and the expression of liver fatty acid-binding protein. Vehicle-treated animals displayed increased hepatic levels of reactive oxygen species and TBARS, 3-NT staining, and iNOS expression; silibinin treatment markedly decreased reactive oxygen species and TBARS and restored 3-NT and iNOS to the levels of control mice. db/db mice fed an MCD diet consistently had increased NFkB p65 and p50 binding activity; silibinin administration significantly decreased the activity of both subunits. Silibinin treatment counteracts the progression of liver injury by modulating lipid homeostasis and suppressing oxidative stress-mediated lipotoxicity and NFkB activation in experimental NASH.

Silibinin improves hepatic and myocardial injury in mice with nonalcoholic steatohepatitis

BACKGROUND

Nonalcoholic fatty liver disease is a chronic metabolic disorder with significant impact on cardiovascular and liver mortality.

AIMS

In this study, we examined the effects of silibinin on liver and myocardium injury in an experimental model of nonalcoholic fatty liver disease.

METHODS

A four-week daily dose of silibinin (20 mg/kg i.p.) was administrated to db/db mice fed a methionine-choline deficient diet. Hepatic and myocardial histology, oxidative stress and inflammatory cytokines were evaluated.

RESULTS

Silibinin administration decreased HOMA-IR, serum ALT and markedly improved hepatic and myocardial damage. Silibinin reduced isoprostanes, 8-deoxyguanosine and nitrites/nitrates in the liver and in the heart of db/db fed the methionine-choline deficient diet, whereas glutathione levels were restored to lean mice levels in both tissues. Consistently, liver mitochondrial respiratory chain activity was significantly impaired in untreated mice and was completely restored in silibinin-treated animals. TNF-α was increased whereas IL-6 was decreased both in the liver and heart of db/db fed methionine-choline deficient diet. Silibinin reversed heart TNF-α and IL-6 expression to control mice levels. Indeed, liver JNK phosphorylation was reduced to control levels in treated animals.

CONCLUSIONS

This study demonstrates a combined effectiveness of silibinin on improving liver and myocardial injury in experimental nonalcoholic fatty liver disease.

Green tea extract supplementation ameliorates CCl4-induced hepatic oxidative stress, fibrosis, and acute-phase protein expression in rat

BACKGROUND/PURPOSE

We evaluated the long-term effects of green tea extract (GTE) supplementation on oxidative stress, biliary acute phase protein expression, and liver function in CCl(4)-induced chronic liver injury.

METHODS

We evaluated the antioxidant activity of GTE in comparison with those of vitamin C, vitamin E, and β-carotene in vitro by using an ultrasensitive chemiluminescence analyzer. Chronic liver injury was induced by intraperitoneally administering carbon tetrachloride (CCl(4)) (1 mL/kg body weight, twice weekly) to female Wistar rats for 8 weeks. The effects of low (4 mg/kg body weight per day) and high (20 mg/kg body weight per day) doses of intragastric GTE on CCl(4)-induced liver dysfunction and fibrosis were examined by measuring the bile and blood reactive oxygen species levels and biochemical parameters by using Western blot and two-dimensional polyacrylamide gel electrophoresis techniques.

RESULTS

GTE has greater scavenging activity against O(2)(-), H(2)O(2), and Hypochlorous acid (HOCl) in vitro than vitamin C, vitamin E, and β-carotene do. In vivo, CCl(4) markedly increased bile and blood reactive oxygen species production, lipid accumulation, number of infiltrated leukocytes, fibrosis, hepatic hydroxyproline content, and plasma alanine aminotransferase and aspartate aminotransferase activities, and reduced plasma albumin levels. Two-dimensional polyacrylamide gel electrophoresis revealed that CCl(4) increased the acute-phase expression of six biliary proteins and decreased hepatic B-cell lymphoma 2 (Bcl-2), catalase, and CuZn superoxide dismutase protein expression. GTE supplementation attenuated CCl(4)-enhanced oxidative stress, levels of biochemical parameters, pathology, and acute-phase protein secretion, and preserved antioxidant/antiapoptotic protein expression.

CONCLUSION

GTE supplementation attenuates CCl(4)-induced hepatic oxidative stress, fibrosis, acute phase protein excretion, and hepatic dysfunction via the antioxidant and antiapoptotic defense mechanisms.

Silibinin induced-autophagic and apoptotic death is associated with an increase in reactive oxygen and nitrogen species in HeLa cells

Silibinin, as the major active constituent of silymarin, has its various biological effects. Here, we investigated the inhibitory effects of silibinin on HeLa cell growth in relation to autophagy and apoptosis induced by reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation. Silibinin dose and time-dependently decreased cell growth cultured in medium containing 10% fetal bovine serum or in serum free media (SFM) with an IC(50) of approximately 80-100 and 40-60 μM at 24 h, respectively. Silibinin induced autophagy at 12 h, confirmed by monodansylcadervarine (MDC) staining and up-regulation of beclin-1, and induced apoptosis at 24 h, detected by observation of apoptotic bodies and activation of caspase-3. 3-methyladenine (3-MA) inhibited silibinin-induced autophagy and attenuated the silibinin's inhibitory effect on cell viability, suggesting that autophagy enhanced silibinin-induced cell death. Silibinin increased ROS levels at 12 h, and ROS scavenger, N-acetylcysteine (NAC), significantly reversed the cytotoxicity of silibinin through inhibiting both autophagy and apoptosis. Specific antioxidants were applied and results indicated that hydroxyl radical (·OH) was the major ROS induced by silibinin, and OH scavenger glutathione (GSH) inhibited apoptosis and autophagy. Silibinin also generated RNS production in the cells at 12 h. High concentration of N omega-nitro-l-arginine methyl ester (L-NAME) as nitric oxide synthase (NOS) inhibitor attenuated the cytotoxicity of silibinin by decreasing ROS levels, leading to down-regulation of apoptosis. Silibinin also could interrupt the respiring functions of mitochondria, leading to ROS production and oxidative damage.