Silymarin and Its Role in Chronic Diseases

Bioactive Flavonoids in Protecting Against Endothelial Dysfunction and Atherosclerosis

Atherosclerosis is a common cardiovascular disease closely associated with factors such as hyperlipidaemia and chronic inflammation. Among them, endothelial dysfunction serves as a major predisposing factor. Vascular endothelial dysfunction is manifested by impaired endothelium-dependent vasodilation, enhanced oxidative stress, chronic inflammation, leukocyte adhesion and hyperpermeability, endothelial senescence, and endothelial-mesenchymal transition (EndoMT). Flavonoids are known for their antioxidant activity, eliminating oxidative stress induced by reactive oxygen species (ROS), thereby preventing the oxidation of low-density lipoprotein (LDL) cholesterol, reducing platelet aggregation, alleviating ischemic damage, and improving vascular function. Flavonoids have also been shown to possess anti-inflammatory activity and to protect the cardiovascular system. This review focuses on the protective effects of these naturally-occuring bioactive flavonoids against the initiation and progression of atherosclerosis through their effects on endothelial cells including, but not limited to, their antioxidant, anti-inflammatory, anti-thrombotic, and lipid-lowering properties. However, more clinical evidences are still needed to determine the exact role and optimal dosage of these compounds in the treatment of atherosclerosis.

Effects of silymarin supplementation on liver and kidney functions: A systematic review and dose-response meta-analysis

It is suggested that supplementation with silymarin (SIL) has beneficial impacts on kidney and liver functions. This systematic review and dose-response meta-analysis assessed the impact of SIL administration on certain hepatic, renal, and oxidative stress markers. A systematic search was conducted in various databases to identify relevant trials published until January 2023. Randomized controlled trials (RCTs) that evaluated the effects of SIL on kidney and liver markers were included. A random-effects model was used for the analysis and 41 RCTs were included. The pooled results indicated that SIL supplementation led to a significant reduction in serum levels of alkaline phosphatase, alanine transaminase, creatinine, and aspartate aminotransferase, along with a substantial elevation in serum glutathione in the SIL-treated group compared to their untreated counterparts. In addition, there was a nonsignificant decrease in serum levels of gamma-glutamyl transferase, malondialdehyde (MDA), total bilirubin, albumin (Alb), total antioxidant capacity, and blood urea nitrogen. Sub-group analyses revealed a considerable decline in MDA and Alb serum values among SIL-treated participants with liver disease in trials with a longer duration (≥12 weeks). These findings suggest that SIL may ameliorate certain liver markers with potential hepatoprotective effects, specifically with long-term and high-dose supplementation. However, its nephroprotective effects and impact on oxidative stress markers were not observed. Additional high-quality RCTs with longer durations are required to determine the clinical efficacy of SIL supplementation on renal and oxidative stress markers.

Silymarin inhibits dermal gelatinolytic activity and reduces cutaneous inflammation

Milk thistle (Silybum marianum) is well-known for its antioxidant activity due to the presence of silymarin. Albeit some studies show a potential for skin inflammation, its activity against dermal MMP-9 and MMP-2 remains to be studied. Silymarin isolated from an S. marianum herbal extract was tested for gelatinase inhibition in the presence of isolated MMP-9 and in dermal adenocarcinome HaCaT cells. Silymarin was then further tested in vivo, using a cutaneous inflammation mice model mediated by reactive oxygen species. Silymarin was able to significantly inhibit gelatinolytic activity in vitro without impairing cell growth and viability. Furthermore, inhibition was more pronounced in cells than with the isolated gelatinase, suggesting an additional effect upon metabolic pathways. In vivo, silymarin was able to reduce ear edema up to 74% and attenuated histological lesions. Results highlight silymarin potential for application in skin inflammatory disorders via gelatinase inhibition.

Impacts of Supplementation with Silymarin on Cardiovascular Risk Factors: A Systematic Review and Dose-Response Meta-Analysis

It has been suggested that silymarin (SIL) supplementation has positive effects on cardiovascular health and reduces the risk of cardiometabolic syndrome (CMS). This systematic review and dose-response meta-analysis assessed the impacts of SIL administration on cardiovascular risk factors. A systematic search of multiple databases was performed to identify eligible controlled trials published up to January 2023. The analysis used a random-effects model and included 33 trials with 1943 participants. It was revealed that SIL supplementation led to a notable reduction in serum levels of fasting blood glucose (FBG) (weighted mean difference (WMD): -21.68 mg/dL, 95% CI: -31.37, -11.99; p < 0.001), diastolic blood pressure (DBP) (WMD: -1.25 mmHg; 95% CI: -2.25, -0.26; p = 0.013), total cholesterol (TC) (WMD: -13.97 mg/dL, 95% CI: -23.09, -4.85; p = 0.003), triglycerides (TG) (WMD: -26.22 mg/dL, 95% CI: -40.32, -12.12; p < 0.001), fasting insulin (WMD: -3.76 mU/mL, 95% CI: -4.80, -2.72; p < 0.001), low-density lipoprotein (LDL) (WMD: -17.13 mg/dL, 95% CI: -25.63, -8.63; p < 0.001), and hemoglobin A1C (HbA1c) (WMD: -0.85%, 95% CI: -1.27, -0.43; p < 0.001) in the SIL-treated groups compared to their untreated counterparts. In addition, there were no substantial differences in body mass index (BMI), systolic blood pressure (SBP), C-reactive protein (CRP), body weight, and high-density lipoprotein (HDL) between the two groups. These outcomes suggest that SIL consumption reduces certain CMS risk factors and has favorable impacts on lipid and glycemic profiles with potential hypotensive effects. These findings should be supported by additional trials with larger sample sizes and longer durations.

Pharmaceutical prospects of Silymarin for the treatment of neurological patients: an updated insight

Background

Silymarin is a polyphenolic flavonoid complex extricated from dried fruits and seeds of the plant Silybum marianum L. Chemically, it is a mixture of flavonolignan complexes consisting of silybin, isosilybin, silychristin, silydianin, a minor quantity of taxifolin, and other polyphenolic compounds, which possess different bio medicinal values.

Purpose

This review critically looks into the current status, pharmaceutical prospects and limitations of the clinical application of Silymarin for treating neurological disorders. In particular, Silymarin's medicinal properties and molecular mechanisms are focused on providing a better-compiled understanding helpful in its neuro-pharmacological or therapeutic aspects.

Methods

This review was compiled by the literature search done using three databases, i.e., PubMed (Medline), EMBASE and Science Direct, up to January 2023, using the keywords-Silymarin, neurological disorders, cognitive disorders, Type 2 Diabetes, pharmaceutical prospects and treatment. Then, potentially relevant publications and studies (matching the eligible criteria) were retrieved and selected to explain in this review using PRISMA 2020 (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) study flow chart.

Result

Since its discovery, it has been widely studied as a hepatoprotective drug for various liver disorders. However, in the last 10-15 years, several research studies have shown its putative neuroprotective nature against various brain disorders, including psychiatric, neurodegenerative, cognitive, metabolic and other neurological disorders. The main underlying neuroprotective mechanisms in preventing and curing such disorders are the antioxidant, anti-inflammatory, anti-apoptotic, pro-neurotrophic and pro-estrogenic nature of the bioactive molecules.

Conclusion

This review provides a lucid summary of the well-studied neuroprotective effects of Silymarin, its underlying molecular mechanisms and current limitations for its usage during neurological disorders. Finally, we have suggested a future course of action for developing it as a novel herbal drug for the treatment of brain diseases.

The novel hepatoprotective mechanisms of silibinin-phospholipid complex against d-GalN/LPS-induced acute liver injury

BACKGROUND & AIMS

Silibinin-phospholipid complex (SPC) has been utilized to treat acute liver injury clinically. Nevertheless, the hepatoprotective mechanism of SPC remains to be further dissected in response to new insights into the pathogenesis of acute liver injury. Very recently, we have documented, for the first time, that M2-like macrophages exert the hepatoprotection against acute insult through inhibiting necroptosis-S100A9-necroinflammation. In the present work, we integrated this new finding into the mechanism of action of SPC, and attempted to dissect the hepatoprotective mechanism of SPC from this new perspective.

METHODS

SPC and corresponding controls were administered intragastrically into control mice subjected to d-GalN/LPS challenge. The hepatic damage was assessed, and the expression of necroptosis-S100A9-necroinflammation signaling molecules was detected. The correlation between SPC and macrophage activation was investigated. The expression of miR-223-3p and its regulation on macrophage activation were analyzed. The targeted inhibitory effects of miR-223-3p on necroptosis and necroinflammation signaling molecules were confirmed.

RESULTS

SPC alleviated remarkably the hepatic damage triggered by d-GalN/LPS. The administration of SPC inhibited the expression of necroptosis-S100A9-necroinflammation signaling molecules. The levels of M2-like macrophage markers were increased significantly in SPC-treated mice or macrophages. miR-223-3p expression was enhanced in SPC-treated mice. miR-223-3p transfer led to up-regulated expression of M2-like macrophage markers. miR-223-3p directly targeted 3' UTR of RIPK3 and NLRP3, and the expression of necroptosis and necroinflammation signaling molecules was inhibited in miR-223-3p-transferred hepatocytes and macrophages.

CONCLUSIONS

SPC alleviates acute liver injury through up-regulating the expression of miR-223-3p. MiR-223-3p further promotes M2-like macrophage activation and the targeted inhibition of necroptosis and necroinflammation. Our findings provide novel insight into the hepatoprotective mechanism of SPC against acute liver injury.

Anticancer natural products targeting immune checkpoint protein network

Normal cells express surface proteins that bind to immune checkpoint proteins on immune cells to turn them off, whereby the immune system does not attack normal healthy cells. Cancer cells can also utilize this same protective mechanism by expressing surface proteins that can interact with checkpoint proteins on immune cells to overcome the immune surveillance. Immunotherapy is making the best use of the body's own immune system to reinforce anti-tumor responses. The most generally used immunotherapy is the control of immune checkpoints including the cytotoxic T lymphocyte-associated molecule 4 (CTLA-4), programmed cell deathreceptor 1 (PD-1), or programmed cell death ligand-1 (PD-L1). In spite of the clinical effectiveness of immune checkpoint inhibitors, the overall response rate still remains low. Therefore, there have been considerable efforts in searching for alternative immune checkpoint proteins that may work as new therapeutic targets for treatment of cancer. Recent studies have identified several additional novel immune checkpoint targets, including lymphocyte activation gene-3, T cell immunoglobulin and mucin-domain containing-3, T cell immunoglobulin and immunoreceptor tyrosine-based inhibition motif domain, V-domain Ig suppressor of T cell activation, B7 homolog 3 protein, B and T cell lymphocyte attenuator, and inducible T cell COStimulator. Natural compounds, especially those present in medicinal or dietary plants, have been investigated for their anti-tumor effects in various in vitro and in vivo models. Some phytochemicals exert anti-tumor activities based on immunoregulatioby blocking interaction between proteins involved in immune checkpoint signal transduction or regulating their expression/activity. Recently, synergistic anti-cancer effects of diverse phytochemicals with anti-PD-1/PD-L1 or anti-CTLA-4 monoclonal antibody drugs have been continuously reported. Considering an increasing attention to noteworthy therapeutic effects of immune checkpoint inhibitors in the cancer therapy, this review focuses on regulatory effects of selected phytochemicals on immune checkpoint protein network and their combinational effectiveness with immune checkpoint inhibitors targeting tumor cells.

A randomized trial assessing the efficacy of Silymarin on endometrioma-related manifestations

To study the effect of silymarin on the Interleukin-6 (IL-6) level, size of endometrioma lesion, pain, sexual function, and Quality of Life (QoL) in women diagnosed with endometriosis. This randomized, double-blind placebo-controlled clinical trial was performed on 70 women with endometriosis which was divided into two groups of intervention and control. The intervention was 140 mg silymarin (or matching placebo) administered twice daily for 12 weeks. The volume of endometrioma lesions, the level of IL-6 concentration in serum, pain, sexual function, and QoL were analyzed before and after the intervention. The means of endometrioma volume (P = 0.04), IL-6 (P = 0.002), and pain (P < 0.001) were reduced significantly in the silymarin group after intervention. However, the QoL and female sexual function did not improve substantially in the two groups (P > 0.05). Silymarin significantly reduced interleukin-6 levels, sizes of endometrioma lesions, and pain-related symptoms. The trial has been registered in the Iranian Registry of Clinical Trials (IRCT20150905023897N5) on 4th February 2020 (04/02/2020) ( https://en.irct.ir/trial/42215 ) and the date of initial participant enrollment was 2nd March 2020 (02/03/2020).

Mechanistic Insights into the Pharmacological Significance of Silymarin

Medicinal plants are considered the reservoir of diverse therapeutic agents and have been traditionally employed worldwide to heal various ailments for several decades. Silymarin is a plant-derived mixture of polyphenolic flavonoids originating from the fruits and akenes of Silybum marianum and contains three flavonolignans, silibinins (silybins), silychristin and silydianin, along with taxifolin. Silybins are the major constituents in silymarin with almost 70–80% abundance and are accountable for most of the observed therapeutic activity. Silymarin has also been acknowledged from the ancient period and is utilized in European and Asian systems of traditional medicine for treating various liver disorders. The contemporary literature reveals that silymarin is employed significantly as a neuroprotective, hepatoprotective, cardioprotective, antioxidant, anti-cancer, anti-diabetic, anti-viral, anti-hypertensive, immunomodulator, anti-inflammatory, photoprotective and detoxification agent by targeting various cellular and molecular pathways, including MAPK, mTOR, β-catenin and Akt, different receptors and growth factors, as well as inhibiting numerous enzymes and the gene expression of several apoptotic proteins and inflammatory cytokines. Therefore, the current review aims to recapitulate and update the existing knowledge regarding the pharmacological potential of silymarin as evidenced by vast cellular, animal, and clinical studies, with a particular emphasis on its mechanisms of action.

Silybum marianum seed extract supplementation positively affects the body weight of weaned piglets by improving voluntary feed intake

This study was conducted to evaluate the effects of dietary supplementation of Silybum marianum seed (SMS) extract on the growth performance, nutrient digestibility, fecal noxious gas emission, and hematology parameters in weaned piglets. A total of 120, 21-day-old weaned piglets ([Yorkshire × Landrace] × Duroc) were randomly assigned to 3 groups based on the average initial body weight (6.46 ± 0.45 kg). There were 8 replicate pens per treatment and 5 pigs (mixed sex) per pen. The experimental period was 42 days. Dietary groups included a basal diet, and a basal diet supplemented with 0.05% or 0.10% SMS extract. Feeding weaned piglets with SMS extract containing diet significantly increased average daily gain and average daily feed intake. Additionally, the supplementation of SMS extract had no significant effects on nutrient digestibility, serum hematology, and fecal noxious gas emission parameters. We considered that the supplementation of SMS extract had positive effects on the voluntary feed intake in weaned piglets, thus improving growth performance.

Nanoparticles as phytochemical carriers for cancer treatment: News of the last decade

INTRODUCTION

The development and application of novel therapeutic medicines for the treatment of cancer are of vital importance to improve the disease's outcome and survival rate. One noteworthy treatment approach is the use of biologically active compounds present in natural products. Even though these phytocompounds present anti-inflammatory, antioxidant, and anticancer properties, their use is limited essentially due to poor systemic delivery, low bioavailability, and water solubility concerns. To make full use of the anticancer potential of natural products, these limitations need to be technologically addressed. In this sense, nanotechnology emerges as a promising drug delivery system strategy.

AREAS COVERED

In this review, the benefits and potential of nanodelivery systems for natural products encapsulation as promising therapeutic approaches for cancer, which were developed during the last decade, are highlighted.

EXPERT OPINION

The nanotechnology area has been under extensive research in the medical field given its capacity for improving the therapeutic potential of drugs by increasing their bioavailability and allowing a targeted delivery to the tumor site. Thereby, the nanoencapsulation of phytocompounds can have a direct impact on the recognized therapeutic activity of natural products towards cancer.

The Effects of Silymarin on Acetaminophen-Induced Acute Hepatic and Renal Toxicities in Domestic Pigeons (Columba livia)

This study evaluated the effects of silymarin on acetaminophen-induced acute liver and kidney toxicities in domestic pigeons (Columba livia). Standard colorimetric methods with commercial kits were used to measure the serum activities or levels of biomarkers associated with liver and kidney damage, such as aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, urea, uric acid, total protein, albumin, and total cholesterol, in 21 pigeons randomly assigned into 3 groups (A, B, and C). Groups A and B were administered acetaminophen 3000 mg/ kg PO q24h at the beginning of the experiment (hour 0). Group B pigeons were further treated with silymarin 35 mg/kg, starting at 12 hours after acetaminophen exposure (post-AA), with the silymarin treatment continuing q12h for 3 days. Group C pigeons served as the control group and were given tap water as the placebo. Blood was collected from the pigeons at hours 0, 12, 24, 48, and 72 of the experiment for serum biochemistry analyses. The results showed that treatment of group B pigeons with silymarin decreased the serum levels of aspartate aminotransferase, alanine aminotransferase, urea, and uric acid compared with the untreated control (group A). It also prevented decreases in serum alkaline phosphatase, total protein, albumin, and cholesterol seen in Group A. Mortality, which was 86% in the untreated control (group A), was completely prevented in group B. It was concluded that silymarin remediated the effects of acetaminophen-induced acute toxic liver and kidney injuries, which may result in pigeon mortality.

Therapies with Antioxidant Potential in Psoriasis, Vitiligo, and Lichen Planus

Oxidative stress plays an important pathogenetic role in many chronic inflammatory diseases, including those of dermatological interest. In particular, regarding psoriasis, vitiligo, and lichen planus, excess reactive oxygen species and a decline in endogenous antioxidant systems are observed. In this regard, treatments with antioxidant properties could be appropriate therapeutic options. To date, clinical trials in dermatology on these treatments are limited. We reviewed the available studies on the efficacy of antioxidant therapies in psoriasis, vitiligo, and lichen planus. The role of herbal derivatives, vitamins, and trace elements was analyzed. The antioxidant properties of conventional therapies were also evaluated. Data from the literature suggest that antioxidants might be useful, but available studies on this topic are limited, heterogeneous, not completely standardized, and on small populations. Furthermore, in most cases, antioxidants alone are unable to induce significant clinical changes, except perhaps in mild forms, and must be used in conjunction with standard drug treatments to achieve measurable results. Further studies need to be conducted, considering larger populations and using internationally validated scales, in order to compare the results and clinical efficacy.

Protective Effects of Silymarin Against D-Gal/LPS-Induced Organ Damage and Inflammation in Mice

AIM

Silymarin contains various flavonoids and exhibits antioxidative, anti-inflammatory, and anticancer effects, in addition to other pharmacological properties. This study explored the alleviating effect of silymarin on multiple-organ damage induced by D-galactose/lipopolysaccharide in Kunming mice.

METHODS

Kunming mice were injected intraperitoneally with D-galactose (30 mg/kg·BW)/LPS (3 μg/kg·BW) and then treated using silymarin with different doses (75 mg/kg·bw and 150 mg/kg·bw) via intragastric administration. Changes in organ indexes, pathological changes, liver-function index, biochemical indexes, molecular biological indexes, and genes related to the oxidation and inflammation of main organs were evaluated.

RESULTS

After the mice were treated with silymarin, their body weight showed no significant change, and the liver, kidney, and lung indexes of the treated mice were higher than those of the model group; meanwhile, the corresponding histopathological formation was reduced. Compared with the model group, the silymarin-treated group showed reductions in ALT, AST, and liver function indexes in the mouse serum. Silymarin treatment also increased the SOD, CAT, GSH, GSH-Px, T-AOC, IL-10, and IL-12 levels, as well as reduced the MDA, NO, IL-6, IL-1β, TNF-α, IFN-γ levels in the mouse serum and liver tissues. In addition, quantitative polymerase chain reaction analysis indicated that the mRNA expression levels of SOD1, SOD2, CAT, GSH-Px, IL-10, Nrf2, HO-1, NQO1, Trx, and IκB-α were higher in the liver tissue of the silymarin-treated mice than in those of the model group; meanwhile, the mRNA expression levels of IL-6, IL-1β, TNF-α, IFN-γ, NF-κB, NLRP3, COX2, and p38 were lower than those in the model group.

CONCLUSION

Silymarin, which exhibits antioxidative and anti-inflammatory effects, can alleviate the liver, lung, and kidney damage induced by D-galactose/lipopolysaccharide. High-dose (150 mg/kg·bw) silymarin can more effectively inhibit organ damage, compared with low-dose silymarin (75 mg/kg·bw) in Kunming mice.

Phyto-pharmacological perspective of Silymarin: A potential prophylactic or therapeutic agent for COVID-19, based on its promising immunomodulatory, anti-coagulant and anti-viral property

Coronavirus disease 2019 (COVID‐19) triggered by a new viral pathogen, named severe acute respiratory syndrome Coronavirus‐2 (SARS‐CoV‐2), is now a global health emergency. This debilitating viral pandemic not only paralyzed the normal daily life of the global community but also spread rapidly via global travel. To date there are no effective vaccines or specific treatments against this highly contagious virus; therefore, there is an urgent need to advocate novel prophylactic or therapeutic interventions for COVID‐19. This brief opinion critically discusses the potential of Silymarin, a flavonolignan with diverse pharmacological activity having antiinflammatory, antioxidant, antiplatelet, and antiviral properties, with versatile immune‐cytokine regulatory functions, that able to bind with transmembrane protease serine 2 (TMPRSS2) and induce endogenous antiviral cytokine interferon‐stimulated gene 15, for the management of COVID‐19. Silymarin inhibits the expression of host cell surface receptor TMPRSS2 with a docking binding energy corresponding to −1,350.61 kcal/mol and a full fitness score of −8.11. The binding affinity of silymarin with an impressive virtual score exhibits significant potential to interfere with SARS‐CoV‐2 replication. We propose in‐depth pre‐clinical and clinical review studies of silymarin for the development of anti‐COVID‐19 lead, based on its clinical manifestations of COVID‐19 and multifaceted bioactivities.

Silymarin mitigates bile duct obstruction-induced cholemic nephropathy

Bile duct obstruction or cholestasis can occur by several diseases or xenobiotics. Cholestasis and the accumulation of the bile constituents in the liver primarily damage this organ. On the other hand, extrahepatic organs are also affected by cholestasis. The kidney is the most affected tissue during cholestatic liver injury. Cholestasis-associated renal injury is known as cholemic nephropathy (CN). Several lines of evidence specify the involvement of oxidative stress and mitochondrial impairment in the pathogenesis of CN. The current study aimed to assess the role of silymarin as a potent antioxidant on CN-induced oxidative stress and mitochondrial dysfunction in the kidney. Bile duct ligated (BDL) rats were treated with silymarin (10 and 100 mg/kg, oral) for seven consecutive days. A significant increase in reactive oxygen species (ROS), lipid peroxidation, protein carbonylation, and oxidized glutathione (GSSG) levels were evident in the kidney of BDL animals. Moreover, reduced glutathione (GSH) content and total antioxidant capacity were significantly decreased in the kidney of cholestatic rats. Mitochondrial depolarization, decreased mitochondrial dehydrogenases activity, mitochondrial permeabilization, and depleted ATP stores were detected in the kidney mitochondria isolated from BDL animals. Kidney histopathological alterations, as well as serum and urine levels of renal injury biomarkers, were also significantly different in the BDL group. It was found that silymarin treatment significantly ameliorated CN-induced renal injury. The antioxidant effects of silymarin and its positive impact on mitochondrial indices seem to play a significant role in its renoprotective effects during cholestasis.

Enhancing TNBC Chemo-immunotherapy via combination reprogramming tumor immune microenvironment with Immunogenic Cell Death

Tumor-associated fibroblasts (TAFs) play an important role in tumor progression and therapeutic response, especially in the immunosuppressive tumor microenvironment (TME). To remodel immunosuppressive TME of 4T1 tumor, we developed a nano liposome to deliver silybin (SLN, an anti-liver fibrosis Chinese Traditional Medicine). Liposomal silybin (SLN/LIP) possessed a spherical shape with particle sizes of 75.2 nm, high stability, and good accumulation in the tumor site. After treated with SLN/LIP, α-SMA positive TAFs and the deposition of stroma were decreased significantly. SLN/LIP also changed the tumor immune microenvironment through the increase of IFN-γ and IL-12, as well as reduced of TGF-β, SDF-1, IL6 and TNF-α. Importantly, SLN/LIP enhanced the infiltration of cytotoxic T cells (CTLs) and transformed a "cold" tumor into a "hot" tumor. To achieve the higher antitumor efficacy, an immunogenic cell death (ICD) inducer, liposomal doxorubicin (DOX/LIP) was combined with SLN/LIP. The combination treatment led to trigger immunogenic tumor apoptosis, and enhance antitumor immunity, therefore, improved anti-tumor efficiency, and further prolonged survival duration. The combination of liposomal silybin and liposomal doxorubicin might be a new chemo-immunotherapy approach for triple negative breast cancer (TNBC) tumor treatment.

Protective effects of medicinal plant against diabetes induced cardiac disorder: A review

ETHNOPHARMACOLOGY RELEVANCE

Nowadays, there is an increase in global tendency to use medicinal plants as preventive and therapeutic agents to manage diabetes and its long-term complications such as cardiovascular disorders owing to their availability and valuable traditional background.

AIM OF STUDY

This review aims to introduce common medicinal plants, which have been demonstrated to have cardioprotective effects on diabetes and their mechanisms of action.

MATERIALS AND METHODS

Online literature databases, including Web of Sciences, PubMed, Science Direct, Scopus and Google Scholar were searched without date limitation by May 2020. The following keywords (natural products or medicinal plants or herbal medicine or herb or extract) and (diabetes or antidiabetic or hyperglycemic) and (cardiomyopathy or heart or cardioprotective or cardiac or cardio) were used, and after excluding non-relevant articles, 81 original English articles were selected.

RESULTS

The surveyed medicinal plants induced cardioprotective effects mostly through increasing antioxidant effects leading to attenuating ROS production as well as by inhibiting inflammatory signaling pathways and related cytokines. Moreover, they ameliorated the Na+/K + ATPase pump, the L-type Ca₂⁺ channel current, and the intracellular ATP. They also reduced cardiac remodeling and myocardial cell apoptosis through degradation of caspase-3, Bax, P53 protein, enhancement of Bcl-2 protein expression as well as downregulation of TGFβ1 and TNFα expression. In addition, the extracts improved cardiac function through increasing EF% and FS% as well as restoring hemodynamic parameters.

CONCLUSIONS

The reviewed medicinal plants demonstrated cardioprotective manifestations in diabetes through intervention with mechanisms involved in the diabetic heart to restore cardiovascular complications.

The combination of atorvastatin with silymarin enhances hypolipidemic, antioxidant and anti-inflammatory effects in a rat model of metabolic syndrome

Hypolipidemic and cardioprotective effects of statins can be associated with the development of myopathies and new-onset type 2 diabetes. These adverse effects may be related to increased oxidative stress. The plant extract silymarin (SM) is known for its antioxidant and anti-inflammatory actions. We tested the hypothesis that the combination of atorvastatin (ATV) with SM could improve therapy efficacy and eliminate some negative effects of statin on hypertriglyceridemia-induced metabolic disorders. Hereditary hypertriglyceridemic rats were fed a standard diet for four weeks without supplementation; supplemented with ATV (5 mg/kg b. wt./day) or a combination of ATV with 1 % micronized SM (ATV+SM). ATV treatment elevated plasma levels of HDL-cholesterol (p<0.01), glucose and insulin and decreased triglycerides (p<0.001). The combination of ATV+SM led to a significant reduction in insulin, an improvement of glucose tolerance, and the hypolipidemic effect was enhanced compared to ATV alone. Furthermore, ATV supplementation increased skeletal muscle triglycerides but its combination with SM decreased triglycerides accumulation in the muscle (p<0.05) and the liver (p<0.01). In the liver, ATV+SM treatment increased the activities of antioxidant enzymes, glutathione and reduced lipid peroxidation (p<0.001). The combined administration of ATV with SM potentiated the hypolipidemic effect, reduced ectopic lipid accumulation, improved glucose metabolism, and increased antioxidant and anti-inflammatory actions. Our results show that SM increased the effectiveness of statin therapy in a hypertriglyceridemic rat model of metabolic syndrome.

Hawthorn Herbal Preparation from Crataegus oxyacantha Attenuates In Vivo Carbon Tetrachloride -Induced Hepatic Fibrosis via Modulating Oxidative Stress and Inflammation

Hawthorn (HAW) is a herbal preparation extracted from Crataegus oxyacantha. HAW has cardioprotective, antioxidants, anti-inflammatory, and anti-hypotensive effects. HAW’s effect on hepatic fibrosis remains, however, unknown. This study evaluated the impact of HAW on carbon tetrachloride (CCl4)-induced hepatic fibrosis in rats and elucidated its mechanisms. HAW reduced liver index and the serum liver enzyme markers and reduced liver damage, and fibrosis as confirmed by histopathological scoring of hematoxylin-eosin staining. Collagen deposition was reduced in HAW group compared to CCl4 group as confirmed by Masson staining, hydroxyproline content, and both mRNA and protein levels of alpha-smooth muscle actin, collagen 1 and 3. HAW also down regulated the gene expressions of inflammatory markers including interleukin-IL-1β, tumor necrosis factor-α, transforming growth factor-β 1, nuclear factor kappa-B, and cyclooxygenase-2 and decreased the myeloperoxidase activity. The effects of HAW was also associated with decreased levels of hepatic oxidative stress markers (malondialdehyde and P.Carbonyl) and with increased activity of superoxide dismutase. Those effects are possibly mediated by blocking the pro-oxidant machinery and down regulating the inflammatory and profibrotic responses. Finally, chlorogenic acid, epicatechin, rutin, vitexin quercetin, and iso quercetin were identified as the major species of polyphenols of the HAW herbal preparation used here. Therefore, HAW’s potent protecting effects against liver fibrosis predicts a significant beneficial application.

Ethyl acetate extract of Ceiba pentandra (L.) Gaertn. reduces methotrexate-induced renal damage in rats via antioxidant, anti-inflammatory, and antiapoptotic actions

Methotrexate (MTX) is a chemotherapeutic agent and an immunosuppressant used to treat cancer and autoimmune diseases. However, its use is limited by its multi-organ toxicity, including nephrotoxicity, which is related to MTX-driven oxidative stress. Silencing oxidative stressors is therefore an important strategy in minimizing MTX adverse effects.Medicinal plants rich in phenolic compounds are probable candidates to overcome these oxidants. Herein, C. pentandra ethyl acetate extract showed powerful in vitro radical-scavenging potential (IC50 = 0.0716) comparable to those of the standard natural (ascorbic acid, IC50 = 0.045) and synthetic (BHA, IC50 = 0.056) antioxidants. The effect of C. pentandra ethyl acetate extract against MTX-induced nephrotoxicity in rats was evaluated by administering the extract (400 mg/kg/day) or the standard antioxidant silymarin (100 mg/kg/day) orally for 5 days before and 5 days after a single MTX injection (20 mg/kg, i.p.).C. pentandra showed slight superiorities over silymarin in restoring the MTX-impaired renal functions, with approximately twofold decreases in overall kidney function tests. C. pentandra also improved renal antioxidant capacity and reduced the MTX-induced oxidative stress. Moreover, C. pentandra inhibited MTX-initiated apoptotic and inflammatory cascades, and attenuated MTX-induced histopathological changes in renal tissue architecture.Phytochemical investigation of the extract led to the purification of the phenolics quercitrin (1), cinchonains 1a (2) and 1b (3), cis-clovamide (4), trans-clovamide (5), and glochidioboside (6); a structurally similar with many of the reported antioxidant and nephroprotective agents. In conclusion, these data demonstrate that C. pentandra exhibits nephroprotective effect against MTX-induced kidney damage via its antioxidant, antiapoptotic and anti-inflammatory mechanisms.

TAXONOMY

Functional Disorder, Traditional Medicine, Herbal Medicine.

The effect of combined diet containing n-3 polyunsaturated fatty acids and silymarin on metabolic syndrome in rats

The risk of development of metabolic syndrome can be increased by hypertriglyceridemia. A search for effective therapy is a subject of considerable attention. Therefore, our hypothesis is that the fish oil (containing polyunsaturated fatty acids; n-3 PUFA) in a combination with silymarin can more effectively protect against hypertriglyceridemia-induced metabolic disturbances. The study was conducted using a unique non-obese strain of rats with hereditary hypertriglyceridemia an accepted model of metabolic syndrome. Adult male rats were treated with n-3 PUFA (300 mg/kg/day) without or with 1 % micronized silymarin in a diet for 4 weeks. The treatment with the diet containing n-3 PUFA and silymarin significantly reduced concentrations of serum triglycerides (-45 %), total cholesterol (-18 %), non-esterified fatty acids (-33 %), and ectopic lipid accumulation in skeletal muscle (-35 %) compared to controls. In addition, an increase in Abcg5 and Abcg8 mRNA expression (as genes affecting lipid homeostasis) as well as in protein content of ABCG5 (+78 %) and ABCG8 (+232 %) transporters have been determined in the liver of treated rats. Our findings suggest that this combined diet could be used in the prevention of hypertriglyceridemia-induced metabolic disorders.

Modulatory Effects of Silymarin on Benzo[a]pyrene-Induced Hepatotoxicity

Benzo[a]pyrene (B[a]P), a polycyclic aromatic hydrocarbon, is a group 1 carcinogen that introduces mutagenic DNA adducts into the genome. In this study, we investigated the molecular mechanisms underlying the involvement of silymarin in the reduction of DNA adduct formation by B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), induced by B[a]P. B[a]P exhibited toxicity in HepG2 cells, whereas co-treatment of the cells with B[a]P and silymarin reduced the formation of BPDE-DNA adducts, thereby increasing cell viability. Determination of the level of major B[a]P metabolites in the treated cells showed that BPDE levels were reduced by silymarin. Nuclear factor erythroid 2-related factor 2 (Nrf2) and pregnane X receptor (PXR) were found to be involved in the activation of detoxifying genes against B[a]P-mediated toxicity. Silymarin did not increase the expression of these major transcription factors, but greatly facilitated their nuclear translocation. In this manner, treatment of HepG2 cells with silymarin modulated detoxification enzymes through NRF2 and PXR to eliminate B[a]P metabolites. Knockdown of Nrf2 abolished the preventive effect of silymarin on BPDE-DNA adduct formation, indicating that activation of the Nrf2 pathway plays a key role in preventing B[a]P-induced genotoxicity. Our results suggest that silymarin has anti-genotoxic effects, as it prevents BPDE-DNA adduct formation by modulating the Nrf2 and PXR signaling pathways.

Ameliorative effects of silymarin on HCl-induced acute lung injury in rats; role of the Nrf-2/HO-1 pathway

OBJECTIVES

Aspiration is a common cause of acute lung injury (ALI), which lacks an effective treatment. Inflammation and oxidative stress play key roles in ALI development. Silymarin is an active extract of Silybum marianum plant seeds (milk thistle). Silymarin has potent anti-inflammatory and antioxidant effects; however its role in aspiration induced ALI has not been investigated. The aim of this study is to investigate the role of silymarin in the treatment of hydrochloric acid (HCl) aspiration induced ALI and explores its mechanisms of action.

MATERIALS AND METHODS

The study included three groups of rats: Control non-treated group, ALI group (intra-tracheal HCl injected), and silymarin treated ALI group. White blood cells (WBCs) with differential count, oxidative stress parameters, B-cell lymphoma 2 (Bcl-2), transforming growth factor-beta (TGF-β), cyclooxygenase 2 (COX-2), nuclear factor erythroid 2-related factor-2 (Nrf-2), and heme oxygenase-1 (HO-1) were investigated. Lung tissue histopathology and immunohistochemical expression of survivin and proliferating cell nuclear antigen (PCNA) were also examined.

RESULTS

The results of the study showed that HCL caused histopathological changes in ALI with leukocytopenia and increased oxidative stress biomarkers. It increased TGF-β, up-regulated mRNA expression of COX-2, Nrf-2, and HO-1 and increased survivin and PCNA but decreased Bcl-2. Silymarin ameliorated the histopathological lung injury with further up-regulation of Nrf-2 and HO-1 mRNA and decreased the inflammatory and fibrotic parameters together with up-regulation of the anti-apoptotic and the proliferation parameters.

CONCLUSION

The protective effect of silymarin against ALI is mediated by Nrf-2/HO-1 pathway with subsequent antioxidant, anti-inflammatory, antiapoptotic, and proliferating activities.

Silymarin antiproliferative and apoptotic effects: Insights into its clinical impact in various types of cancer

Silymarin is a complex extract isolated from the plant Silybum marianum, widely known for its prominent antioxidant and hepatoprotective effects, although increasing evidences have reported extraordinary antiproliferative and apoptotic abilities. As a result, several signaling pathways involved in cell cycle control, cell proliferation, and cell death have been deconvoluted as critical mechanisms. In this regard, cyclin and cyclin-dependent pathways have been the most studied ones. Following that, apoptotic pathways, such as p53, Akt, STAT-3, Ras, and caspases pathways, have been extensively studied, although other mechanisms involved in inflammation and angiogenesis have also been highlighted as silymarin-likely targets in cancer therapy. Therefore, the main challenge of this review is to discuss the diverse molecular mechanisms for silymarin antiproliferative and apoptotic effects; most of them largely studied in various types of cancers so far. Clinical trials and combination therapies related to silymarin application in cancer prevention and treatment are presented as well.

Hepatitis C: From inflammatory pathogenesis to anti-inflammatory/hepatoprotective therapy

Hepatitis C virus (HCV) infection commonly causes progressive liver diseases that deteriorate from chronic inflammation to fibrosis, cirrhosis and even to hepatocellular carcinoma. A long-term, persistent and uncontrolled inflammatory response is a hallmark of these diseases and further leads to hepatic injury and more severe disease progression. The levels of inflammatory cytokines and chemokines change with the states of infection and treatment, and therefore, they may serve as candidate biomarkers for disease progression and therapeutic effects. The mechanisms of HCV-induced inflammation involve classic pathogen pattern recognition, inflammasome activation, intrahepatic inflammatory cascade response, and oxidative and endoplasmic reticulum stress. Direct-acting antivirals (DAAs) are the first-choice therapy for effectively eliminating HCV, but DAAs alone are not sufficient to block the uncontrolled inflammation and severe liver injury in HCV-infected individuals. Some patients who achieve a sustained virologic response after DAA therapy are still at a long-term risk for progression to liver cirrhosis and hepatocellular carcinoma. Therefore, coupling with anti-inflammatory/hepatoprotective agents with anti-HCV effects is a promising therapeutic regimen for these patients during or after treatment with DAAs. In this review, we discuss the relationship between inflammatory mediators and HCV infection, summarize the mechanisms of HCV-induced inflammation, and describe the potential roles of anti-inflammatory/hepatoprotective drugs with anti-HCV activity in the treatment of advanced HCV infection.

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.

Baicalein Enhances the Oral Bioavailability and Hepatoprotective Effects of Silybin Through the Inhibition of Efflux Transporters BCRP and MRP2

Although hepatoprotective properties of silybin are well documented, the clinical therapeutic efficacy is limited by its low bioavailability due to absorption rates, extensive phase II metabolism, and biliary excretion. As our previous study indicated that metabolic enzymes may have limited effects on the pharmacokinetic (PK) behavior of silymarin, here, we intended to increase the oral bioavailability and bio-efficacy of silybin through the inhibition of active efflux. In Caco-2 and transfected MDCKII cell models, flavone baicalein significantly inhibited the efflux of silybin as a BCRP and MRP2 inhibitor. In addition, baicalein reduced the biliary excretion index (BEI) and biliary clearance of silybin conjugates in the sandwich-cultured rat hepatocyte (SCH) model, indicating the inhibition of baicalein in biliary excretion of conjugated silybin metabolites. PK study demonstrated that baicalein significantly increased the area under the curve (AUC) and C_max of silybin and its conjugates, suggesting enhanced absorption in vivo. Moreover, coadministration of silybin with baicalein boosted the liver protective, antioxidant, and anti-inflammatory effects of silybin in the carbon tetrachloride (CCl₄)-induced liver injury model in comparison with silybin given alone. In summary, efflux transporters play a critical role in the low bioavailability of silybin, while inhibition of breast cancer resistance protein (BCRP) and multi-drug resistance protein 2 (MRP2) by baicalein can significantly increase the absorption and bio-efficacy of silybin, which provides a new combination therapeutic approach for the treatment of chronic liver diseases.

Lower glycemic indices and lipid profile among type 2 diabetes mellitus patients who received novel dose of Silybum marianum (L.) Gaertn. (silymarin) extract supplement: A Triple-blinded randomized controlled clinical trial

OBJECTIVE

This randomized clinical trial was conducted to evaluate the effects of silymarin supplementation on glycemic indices and serum lipid profile in type 2 diabetes mellitus (T2DM) patients.

METHODS

40 T2DM patients (twenty male and twenty female), 25-50 years of age and on stable medication, were recruited for the present paralleled, randomized, triple-blinded, placebo-controlled clinical trial. The participants were randomly assigned to the silymarin or placebo groups, in which the patients either received 140 mg of silymarin, thrice daily (n = 20) or placebo (n = 20) for 45 days. Anthropometric and dietary intake data were collected at the baseline and end of the trial. Fasting blood samples were collected, and glycemic indices and lipid profile were determined at baseline, as well as the end of the study.

RESULTS

Silymarin supplementation led to significant reduction in fasting blood sugar, serum insulin, homeostatic model assessment for insulin resistance, serum triglyceride and triglyceride to high-density lipoprotein cholesterol ratio as compared to the placebo, by 11.01, 14.35, 25.92, 23.7 and 27.67% respectively. There was significant increase in high-density lipoprotein cholesterol levels and quantitative insulin sensitivity check index in the silymarin group as compared to the placebo group, by 6.88 and 5.64% respectively, (p < 0.05). Total cholesterol and low-density lipoprotein cholesterol concentrations significantly decreased in the silymarin group as compared to the baseline, by 7.93 (p = 0.001) and 7.15% (p = 0.02), respectively.

CONCLUSION

Silymarin supplementation may improve the glycemic indices and lipid profiles of T2DM patients. More studies are needed to validate the adjunct use of silymarin for metabolic control of T2DM patients.

Silymarin/Silybin and Chronic Liver Disease: A Marriage of Many Years

Silymarin is the extract of Silybum marianum, or milk thistle, and its major active compound is silybin, which has a remarkable biological effect. It is used in different liver disorders, particularly chronic liver diseases, cirrhosis and hepatocellular carcinoma, because of its antioxidant, anti-inflammatory and antifibrotic power. Indeed, the anti-oxidant and anti-inflammatory effect of silymarin is oriented towards the reduction of virus-related liver damages through inflammatory cascade softening and immune system modulation. It also has a direct antiviral effect associated with its intravenous administration in hepatitis C virus infection. With respect to alcohol abuse, silymarin is able to increase cellular vitality and to reduce both lipid peroxidation and cellular necrosis. Furthermore, silymarin/silybin use has important biological effects in non-alcoholic fatty liver disease. These substances antagonize the progression of non-alcoholic fatty liver disease, by intervening in various therapeutic targets: oxidative stress, insulin resistance, liver fat accumulation and mitochondrial dysfunction. Silymarin is also used in liver cirrhosis and hepatocellular carcinoma that represent common end stages of different hepatopathies by modulating different molecular patterns. Therefore, the aim of this review is to examine scientific studies concerning the effects derived from silymarin/silybin use in chronic liver diseases, cirrhosis and hepatocellular carcinoma.