Silybin regulates P450s activity by attenuating endoplasmic reticulum stress in mouse nonalcoholic fatty liver disease.

Cytochrome P450s are important phase I metabolic enzymes located on endoplasmic reticulum (ER) involved in the metabolism of endogenous and exogenous substances. Our previous study showed that a hepatoprotective agent silybin restored CYP3A expression in mouse nonalcoholic fatty liver disease (NAFLD). In this study we investigated how silybin regulated P450s activity during NAFLD. C57BL/6 mice were fed a high-fat-diet (HFD) for 8 weeks to induce NAFLD, and were administered silybin (50, 100 mg ·kg-1 ·d-1, i.g.) in the last 4 weeks. We showed that HFD intake induced hepatic steatosis and ER stress, leading to significant inhibition on the activity of five primary P450s including CYP1A2, CYP2B6, CYP2C19, CYP2D6, and CYP3A in liver microsomes. These changes were dose-dependently reversed by silybin administration. The beneficial effects of silybin were also observed in TG-stimulated HepG2 cells in vitro. To clarify the underlying mechanism, we examined the components involved in the P450 catalytic system, membrane phospholipids and ER membrane fluidity, and found that cytochrome b5 (cyt b5) was significantly downregulated during ER stress, and ER membrane fluidity was also reduced evidenced by DPH polarization and lower polyunsaturated phospholipids levels. The increased ratios of NADP+/NADPH and PC/PE implied Ca2+ release and disruption of cellular Ca2+ homeostasis resulted from mitochondria dysfunction and cytochrome c (cyt c) release. The interaction between cyt c and cyt b5 under ER stress was an important reason for P450s activity inhibition. The effect of silybin throughout the whole course suggested that it regulated P450s activity through its anti-ER stress effect in NAFLD. Our results suggest that ER stress may be crucial for the inhibition of P450s activity in mouse NAFLD and silybin regulates P450s activity by attenuating ER stress.

Liposomal Silybin Improves Glucose and Lipid Metabolisms in Type 2 Diabetes Mellitus Complicated with Non-Alcoholic Fatty Liver Disease via AMPK/TGF-ß1/Smad Signaling.

Improving hepatic glucose and lipid metabolisms is an important strategy to treat type 2 diabetes mellitus complicated with non-alcoholic fatty liver disease (T2DM-NAFLD). Silybin (SLB) has the potential hepatoprotection, while its oral bioavailability is poor. This study aims to investigate the functional role and mechanism of liposomal SLB in modulating glucose/lipid metabolism in T2DM-NAFLD. SLB was prepared by thin film dispersion method and characterized using dynamic light scattering, scanning electron microscope, high performance liquid chromatography and zeta potential analyzer. A rat model of T2DM-NAFLD was used to determine the role of liposomal SLB in regulating glycolipid metabolism and hepatic damage. Rat primary hepatocytes were used to demonstrate the hepatoprotection mechanism of liposomal SLB. The encapsulation efficiency was more than 80%, which showed the average particle size of 119.76 nm. Also, the average Zeta potential was -4.76 mV. These liposomes were spherical. In rats with T2DM-NAFLD, liposomal SLB alleviated insulin resistance and lipid metabolism, thereby improving hepatic lipid accumulation, inflammation and fibrosis. Besides, liposomal SLB elevated AMPK phosphorylation, and decreased collagen I/III, α-smooth muscle actin (α-SMA), transforming growth factor-ß1 (TGF-ß1) and the phosphorylation of Smad2/3. In hepatocyte model, compound C partially reversed the effects of liposomal SLB on cell viability, glycolipid metabolism and AMPK/TGF-ß1/Smad pathway activation. Liposomal SLB ameliorates hepatic glucose and lipid metabolisms in T2DM-NAFLD via activating AMPK/TGF-ß1/Smad pathway, providing an efficient strategy for treating T2DM-NAFLD.

Production of phenylpropanoids and flavonolignans from glycerol by metabolically engineered Escherichia coli.

Phenylpropanoids are a group of plant natural products with medicinal importance derived from aromatic amino acids. Here, we report the production of two representative phenylpropanoids-coniferyl alcohol (CA) and dihydroquercetin (DHQ)-from glycerol by engineered Escherichia coli. First, an E. coli strain capable of producing 187.7 mg/L of CA from glycerol was constructed by the introduction of hpaBC from E. coli and OMT1, 4CL4, and CCR1 from Arabidopsis thaliana to the p-coumaric acid producer. Next, an E. coli strain capable of producing 239.4 mg/L of DHQ from glycerol was constructed by the introduction of F3H, TT7, and CPR from A. thaliana to the naringenin producer, followed by engineering the signal peptide of a cytochrome P450 TT7. Furthermore, to demonstrate the production of flavonolignans, a group of heterodimeric phenylpropanoids, from glycerol, ascorbate peroxidase 1 from Silybum marianum was employed and engineered to produce 0.04 µg/L of silybin and 1.29 µg/L of isosilybin from glycerol by stepwise culture. Finally, a single strain harboring all the 16 necessary genes was constructed, resulting in 0.12 µg/L of isosilybin production directly from glycerol. The strategies described here will be useful for the production of pharmaceutically important yet complex natural products.

Danshao Shugan Granule therapy for non-alcoholic fatty liver disease.

BACKGROUND: Danshao Shugan Granules (DSSG), a traditional Chinese medicine (TCM), is given to protect the liver. The objective is to evaluate the mechanisms of the effects of DSSG on non-alcoholic fatty liver disease (NAFLD). METHODS: 260 patients with NAFLD were randomly allocated to positive control drugs rosiglitazone (n = 30) and Silibinin (n = 50) as well as DSSG (n = 130) and combined DSSG/Silibinin (n = 50) groups, from which 90 patients in the DSSG group were further subdivided into 3 groups (n = 30, each) depending on the severity of symptoms. In total 33 Sprague-Dawley rats were assigned to normal (n = 10) or 45% high-fat diet (n = 23) groups, from which 9 rats served as negative controls, 10 as model controls and 10 were treated with DSSG. RESULTS: DSSG medications had significantly highest effects on B-ultrasonography finding improvements, and reductions of total cholesterol, triglyceride, aspartate transaminase and γ-glutamyl transpeptidase in NAFLD patients. Silibinin application only led to significantly highest alanine transaminase reductions and rosiglitazone medication to significantly highest fasting plasma glucose reductions. In a murine in vivo NAFLD model glucose (GLU), total cholesterol (TC) triacylglycerol (TG) as well as glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT) and gamma-glutamyl transferase (GGT) serum concentrations were all significantly reduced (P < 0.001) and the expression of nuclear factor-κB (NF­κB) was significantly decreased in DSSG treated compared to untreated NAFLD animals (P < 0.001). In addition, the DSSG treated rats exhibited increased superoxide dismutase activity and reduced malondialdehyde values. CONCLUSIONS: DSSG was effective for treating NAFLD patients, which could be attributed to increased activity of superoxide dismutase, a decrease of malondialdehyde as well as reduced NF­κB activity in a NAFLD rat model.

Metabolic profiling of emodin drug-induced liver injury and silybin treatment in rats using ultra-performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry: A metabolomic and mechanistic approach.

Silybin, an active component in the plant Silybum marianum (L.) Gaertn., is commonly used to protect against liver disease. We investigated silybin's protective potential in rat liver against emodin-induced liver injury 4 weeks. It was found that aspartate aminotransferase and direct bilirubin serum biomarkers for liver toxicity significantly increased, and liver histopathology revealed cholestasis and necrosis in rats administered emodin alone, whereas aspartate aminotransferase and total bile acid levels in rats administered emodin and silybin simultaneously were changed compared to rats administered emodin alone. Liver mRNA and protein levels of Cyp7a1-which plays roles in cholesterol metabolism and bile acid synthesis-and Abcb11 (Bsep)-which facilitates bile salt secretion in hepatocyte canaliculi-were significantly altered with emodin, whereas cotreatment with silybin attenuated emodin's adverse effect. Metabolomic analysis using ultra-performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry determined eight potential metabolite biomarkers in serum, urine, and liver tissue. Network analysis was conducted to conceptualize the interplay of genes, metabolites, and metabolic pathways for cholesterol metabolism and bile acid synthesis for liver injury. Overall, rats administered only emodin were shown to be a sound model to investigate fat-associated drug-induced hepatoxicity or liver injury and cotreatment of emodin with silybin prevents fatty liver injury. This metabolomic study revealed that emodin-induced fatty liver injury disrupted bile acid synthesis, vitamin B6 , and glycerophospholipid metabolism pathways and that silybin ameliorates liver injury on these compromised pathways.

Silybin Restored CYP3A Expression through the Sirtuin 2/Nuclear Factor κ-B Pathway in Mouse Nonalcoholic Fatty Liver Disease.

Silybin is widely used as a hepatoprotective agent in various liver disease therapies and has been previously identified as a CYP3A inhibitor. However, little is known about the effect of silybin on CYP3A and the regulatory mechanism during high-fat-diet (HFD)-induced liver inflammation. In our study, we found that silybin restored CYP3A expression and activity that were decreased by HFD and conditioned medium (CM) from palmitate-treated Kupffer cells. Moreover, silybin suppressed liver inflammation in HFD-fed mice and inhibited nuclear factor κ-B translocation into the nucleus through elevation of SIRT2 expression and promotion of p65 deacetylation. This effect was confirmed by overexpression of SIRT2, which suppressed p65 nuclear translocation and restored CYP3A transcription affected by CM. The hepatic NAD+ concentration markedly decreased in HFD-fed mice and CM-treated hepatocytes/HepG2 cells but increased after silybin treatment. Supplementing nicotinamide mononucleotide as an NAD+ donor inhibited p65 acetylation, decreased p65 nuclear translocation, and restored cyp3a transcription in both HepG2 cells and mouse hepatocytes. These results suggest that silybin regulates metabolic enzymes during liver inflammation by a mechanism related to the increase in NAD+ and SIRT2 levels. In addition, silybin enhanced the intracellular NAD+ concentration by decreasing poly-ADP ribosyl polymerase-1 expression. In summary, silybin increased NAD+ concentration, promoted SIRT2 expression, and lowered p65 acetylation both in vivo and in vitro, which supported the recovery of CYP3A expression. These findings indicate that the NAD+/SIRT2 pathway plays an important role in CYP3A regulation during nonalcoholic fatty liver disease. SIGNIFICANCE STATEMENT: This research revealed the differential regulation of CYP3A by silybin under physiological and fatty liver pathological conditions. In the treatment of nonalcoholic fatty liver disease, silybin restored, not inhibited, CYP3A expression and activity through the NAD+/ sirtuin 2 pathway in accordance with its anti-inflammatory effect.

Computational hunting of natural active compounds as an alternative for Remdesivir to target RNA-dependent polymerase.

The hunt for potential lead/drug molecules from different resources, especially from natural resources, for possible treatment of COVID-19 is ongoing. Several compounds have already been identified, but only a few are good enough to show potential against the virus. Among the identified druggable target proteins of SARS-CoV-2, this study focuses on non-structural RNA-dependent RNA polymerase protein (RdRp), a well-known enzyme for both viral genome replication and viral mRNA synthesis, and is therefore considered to be the primary target. In this study, the virtual screening followed by an in-depth docking study of the Compounds Library found that natural compound Cyclocurcumin and Silybin B have strong interaction with RdRp and much better than the remdesivir with free binding energy and inhibition constant value as êzŒ-6.29 kcal/mol and 58.39 µMêzŒ, and êzŒ-7.93kcal/mol and 45.3 µMêzŒ, respectively. The finding indicated that the selected hits (Cyclocurcumin and Silybin B) could act as non-nucleotide anti-polymerase agents, and can be further optimized as a potential inhibitor of RdRp by benchwork experiments.

Intercalation of a flavonoid, silibinin into DNA base pairs: Experimental and theoretical approach.

Polyphenols are secondary plant metabolites, which have received much attention because of their potential health benefits. Silibinin (SIL) is a well-known naturally occurring flavonolignan, which is extensively used in treating a wide variety of diseases as a dietary supplement as well as a prescribed drug. The mechanism of binding of SIL to calf thymus DNA (ctDNA) was investigated by employing multispectroscopic techniques, viz., absorption, fluorescence, and circular dichroism besides viscosity measurements and docking studies. Analysis of fluorescence results indicated that SIL has interacted with ctDNA and quenched its intensity through static quenching mechanism. The binding constant at room temperature was found to be 2.48×104 mol-1 , suggesting moderate binding affinity between SIL and ctDNA. The hypochromicity observed in the absorption spectra of ctDNA in the presence of SIL revealed the intercalation of SIL into ctDNA base pairs. Further, the intercalative mode of binding between SIL and ctDNA was confirmed by viscosity measurements and molecular docking studies. The outcome of present study helps to decipher the interaction mechanism between SIL and DNA at physiological pH, which further assists in the design of a new analogue for better therapeutic effects.

Green production of silybin and isosilybin by merging metabolic engineering approaches and enzymatic catalysis.

Silymarin extracted from milk thistle seeds, is used for treating hepatic diseases. Silybin and isosilybin are its main components, and synthesized from coupling of taxifolin and coniferyl alcohol. Here, the biosynthetic pathways of taxifolin and coniferyl alcohol were reconstructed in Saccharomyces cerevisiae for the first time. To alleviate substantial burden caused by a great deal of genetic manipulation, expression of the enzymes (e.g. ZWF1, TYR1 and ARO8) playing multiple roles in the relevant biosynthetic pathways was selectively optimized. The strain YT1035 overexpressing seven heterologous enzymes and five native enzymes and the strain YC1053 overexpressing seven heterologous enzymes and four native enzymes, respectively produce 336.8 mg/L taxifolin and 201.1 mg/L coniferyl alcohol. Silybin and isosilybin are synthesized from taxifolin and coniferyl alcohol under catalysis of APX1t (the truncated milk thistle peroxidase), with a yield of 62.5%. This study demonstrates an approach for producing silybin and isosilybin from glucose for the first time.

Silibinin down-regulates PD-L1 expression in nasopharyngeal carcinoma by interfering with tumor cell glycolytic metabolism.

The upregulation of checkpoint inhibitor PD-L1 expression has recently been associated with nasopharyngeal carcinoma (NPC) resistance to therapy. The mechanism of induction of PD-L1 has also been linked to enhanced aerobic glycolysis promoted by HIF1-α dysregulation and LDH-A activity in cancer. Here, we investigated the effect of the anti-tumoral compound Silibinin on HIF-1α/LDH-A mediated cancer cell metabolism and PD-L1 expression in NPC. Our results demonstrate that exposure to Silibinin potently inhibits tumor growth and promotes a shift from aerobic glycolysis toward oxidative phosphorylation. The EBV + NPC cell line C666-1 and glycolytic human tumor explants treated with Silibinin displayed a reduction in LDH-A activity which consistently associated with a reduction in lactate levels. This effect was accompanied by an increase in intracellular citrate levels in C666-1 cells. Accordingly, expression of HIF-1α, a critical regulator of glycolysis, was down-regulated after treatment. This event associated with a down-regulation in PD-L1. Altogether, our results provide evidence that silibinin can alter PD-L1 expression by interfering with HIF-1α/LDH-A mediated cell metabolism in NPC. These results provide a new perspective for Silibinin use to overcome PD-L1 mediated NPC resistance to therapy.

Silibinin treatment results in reducing OPA1&MFN1 genes expression in a rat model hepatic ischemia-reperfusion.

The mitochondrial damage has a pivotal role in triggering apoptosis and cell death. This study assessed the effect of silibinin on optical atrophy-1 (OPA1) and mitofusin-1 (MFN1) gene expression in liver tissue during hepatic warm ischemia-reperfusion (IR). Four groups of rats, eight rats each were designed: Vehicle: the rats received normal saline and encountered to laparotomy, Sili: silibinin (60 mg/kg) was administered to animals, IR: the rats received the normal saline and insulted by liver IR procedure, and IR + Sili: silibinin was injected to rats. All groups were subjected to the same process of injection of the solvent or silibinin (30 min before laparotomy or ischemia and immediately after the reperfusion), intraperitoneally (IP). After 3 h of reperfusion, blood and liver tissue samples were collected for future examinations. Our results showed no significant differences between the Vehicle and Sili groups in all assessed parameters. In IR + Sili, the increased serum levels of AST and ALT in comparison with the control group were markedly reduced by silibinin treatment. Silibinin lowered the elevated expression of OPA1 and MFN1 mRNAs in the IR group. Histology revealed silibinin could decline tissue degeneration compared to the IR group. Electron microscopy of control and silibinin groups showed no fusion of mitochondria and tissue degradation both of which were observed in the IR group. The extent of tissue destruction and mitochondrial fusion decreased significantly with silibinin treatment. Silibinin has a protective effect on liver cells against IR induced injuries by preserving mitochondrial membrane.

Gene Expression Analysis and Metabolite Profiling of Silymarin Biosynthesis during Milk Thistle (Silybum marianum (L.) Gaertn.) Fruit Ripening.

Mature fruits (i.e., achenes) of milk thistle (Silybum marianum (L.) Gaertn., Asteraceae) accumulate high amounts of silymarin (SILM), a complex mixture of bioactive flavonolignans deriving from taxifolin. Their biological activities in relation with human health promotion and disease prevention are well described. However, the conditions of their biosynthesis in planta are still obscure. To fill this gap, fruit development stages were first precisely defined to study the accumulation kinetics of SILM constituents during fruit ripening. The accumulation profiles of the SILM components during fruit maturation were determined using the LC-MS analysis of these defined developmental phases. The kinetics of phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS) and peroxidase (POX) activities suggest in situ biosynthesis of SILM from l-Phenylalanine during fruit maturation rather than a transport of precursors to the achene. In particular, in contrast to laccase activity, POX activity was associated with the accumulation of silymarin, thus indicating a possible preferential involvement of peroxidase(s) in the oxidative coupling step leading to flavonolignans. Reference genes have been identified, selected and validated to allow accurate gene expression profiling of candidate biosynthetic genes (PAL, CAD, CHS, F3H, F3'H and POX) related to SILM accumulation. Gene expression profiles were correlated with SILM accumulation kinetic and preferential location in pericarp during S. marianum fruit maturation, reaching maximum biosynthesis when desiccation occurs, thus reinforcing the hypothesis of an in situ biosynthesis. This observation led us to consider the involvement of abscisic acid (ABA), a key phytohormone in the control of fruit ripening process. ABA accumulation timing and location during milk thistle fruit ripening appeared in line with a potential regulation of the SLIM accumulation. A possible transcriptional regulation of SILM biosynthesis by ABA was supported by the presence of ABA-responsive cis-acting elements in the promoter regions of the SILM biosynthetic genes studied. These results pave the way for a better understanding of the biosynthetic regulation of SILM during the maturation of S. marianum fruit and offer important insights to better control the production of these medicinally important compounds.

Evaluation of Mogroside V as a Promising Carrier in Drug Delivery: Improving the Bioavailability and Liver Distribution of Silybin.

The objective of this work was to investigate the capacity of mogroside V (MOG-V), a food additive, as a novel carrier to improve the bioavailability and liver distribution of silybin (SLY). Solid dispersion particles (SDPs) of SLY/MOG-V were prepared utilizing the solvent evaporation method. The physicochemical characterizations of SDPs were evaluated by using dynamic light scattering (DLS), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) measurements. DLS results demonstrated the formation of nanoparticles (206 nm) of SDPs in water. DSC and PXRD analysis revealed that SLY was in amorphous form or molecularly dispersed in SDPs. SDPs also exhibited a major increase in both dissolution rate and saturation solubility, as evidenced by a 1931-fold improvement (2201 µg/mL) in solubility compared with pure SLY (1.14 µg/mL). The pharmacokinetic study in rats showed that oral absorption of SLY/MOG-V SDPs was dramatically increased. The mean value of AUC until 12 h for SLY/MOG-V SDPs (27,481 ng·min/mL) was 24.5-fold higher than that of pure SLY (1122 ng·min/mL). In vivo tissue distribution experiment in mice confirmed that the major distribution tissue was changed from lungs to liver after SLY was loaded into MOG-V. In addition, even orally administrated to mice at a high dose (4.2 g/kg), MOG-V exhibited no undesirable effect on the plasma glucose concentrations. Thus, MOG-V may have the applicability to serve as an ideal excipient for solubilization or as a novel liver targeting carrier for the delivery of SLY.

Characterization of glutathione conjugates derived from reactive metabolites of seven silymarin isomers.

1. Silymarin refers to a class of flavonoid lignans occurring in the fruits and seeds of the Silybum manalttlm (L). Gaertn, and is widely used in dietary supplements. 2. The main active ingredients of silymarin are silychristins A and B, silydianin, silybins A and B, and isosilybins A and B. However, the metabolism of silymarin has never been investigated. The major objectives of the present study were to investigate the metabolic pathways of silymarin isomers and to identify reactive metabolites. 3. Fourteen glutathione (GSH) conjugates were detected in rat/human liver microsomes incubations containing NADPH, GSH and seven individual isomers. Seven GSH conjugates (M1-M7) resulted from demethylated silymarin. M8-M14 originated from hydroxylated silymarin. Moreover, we found that GSH was probably conjugated on either ring A or ring E of silymarin based on the mass spectrometric fragments. In addition, recombinant enzyme incubation experiments demonstrated that CYP3A4 was the predominant P450 responsible for the metabolism of silymarin. 4. Several P450 enzymes were reportedly inactivated by some of bioactive constituents of silymarin to some extent. Our findings facilitate the understanding of mechanisms of the reported inactivation of P450 enzymes induced by silymarin.

Intestinal Permeability Study of Clinically Relevant Formulations of Silibinin in Caco-2 Cell Monolayers.

An ever-growing number of preclinical studies have investigated the tumoricidal activity of the milk thistle flavonolignan silibinin. The clinical value of silibinin as a bona fide anti-cancer therapy, however, remains uncertain with respect to its bioavailability and blood⁻brain barrier (BBB) permeability. To shed some light on the absorption and bioavailability of silibinin, we utilized the Caco-2 cell monolayer model of human intestinal absorption to evaluate the permeation properties of three different formulations of silibinin: silibinin-meglumine, a water-soluble form of silibinin complexed with the amino-sugar meglumine; silibinin-phosphatidylcholine, the phytolipid delivery system Siliphos; and Eurosil85/Euromed, a milk thistle extract that is the active component of the nutraceutical Legasil with enhanced bioavailability. Our approach predicted differential mechanisms of transport and blood⁻brain barrier permeabilities between the silibinin formulations tested. Our assessment might provide valuable information about an idoneous silibinin formulation capable of reaching target cancer tissues and accounting for the observed clinical effects of silibinin, including a recently reported meaningful central nervous system activity against brain metastases.

Metabolism, Transport and Drug-Drug Interactions of Silymarin.

Silymarin, the extract of milk thistle, and its major active flavonolignan silybin, are common products widely used in the phytotherapy of liver diseases. They also have promising effects in protecting the pancreas, kidney, myocardium, and the central nervous system. However, inconsistent results are noted in the different clinical studies due to the low bioavailability of silymarin. Extensive studies were conducted to explore the metabolism and transport of silymarin/silybin as well as the impact of its consumption on the pharmacokinetics of other clinical drugs. Here, we aimed to summarize and highlight the current knowledge of the metabolism and transport of silymarin. It was concluded that the major efflux transporters of silybin are multidrug resistance-associated protein (MRP2) and breast cancer resistance protein (BCRP) based on results from the transporter-overexpressing cell lines and MRP2-deficient (TR-) rats. Nevertheless, compounds that inhibit the efflux transporters MRP2 and BCRP can enhance the absorption and activity of silybin. Although silymarin does inhibit certain drug-metabolizing enzymes and drug transporters, such effects are unlikely to manifest in clinical settings. Overall, silymarin is a safe and well-tolerated phytomedicine.

Albumin-Based Silibinin Nanocrystals Targeting Activated Hepatic Stellate Cells for Liver Fibrosis Therapy.

Activated hepatic stellate cells (aHSCs) are critical during the development and progression of liver fibrosis. Once liver fibrosis occurs, aHSCs highly express secreted protein, acidic and rich in cysteine (SPARC), a typical albumin-binding protein. We designed a nano platform, silibinin albumin nanocrystals (SLB-HSA NCs), to target aHSCs for liver fibrosis therapy. The prepared SLB-HSA NCs showed uniform particle size distribution of approximately 60 nm with PDI < 0.15 and high loading efficiency up to 49.4%. Albumin coated on the surface of nanocrystals was demonstrated to increase cellular uptake by aHSCs through SPARC-mediated endocytosis. In addition, SLB-HSA NCs significantly improved the bioavailability compared with free SLB in pharmacokinetic study. Following tail-vein injection, SLB-HSA NCs were massively accumulated in the fibrotic liver and exhibited enhanced antifibrotic effects in hepatic fibrosis mice. Overall, our findings prove the great potential of SLB-HSA NCs in the targeted treatment of liver fibrosis.

Silibinin supplementation ameliorates the toxic effects of butyl benzyl phthalate on porcine oocytes by eliminating oxidative stress and autophagy.

Butyl benzyl phthalate (BBP) is a common environmental pollutant, it is high in paints, adhesives and other decorative materials, food packaging bags, cleaning agents, is a plasticizer is very widely used in daily life. However, it remains unknown whether BBP causes damage to oocytes cultured in vitro and whether there is an effective rescue strategy. Here, we evaluated the effects of exposure to different concentrations of BBP (10, 50, and 100 µM) on the meiosis of porcine oocytes. The results showed that exposure to BBP (100 µM) severely impaired expansion of cumulus-oocyte complex (COCs) and PBE (control:71.6% vs 100 µM: 48.8%). Spindle conformation and chromosome alignment were also significantly abnormal (34.8% and 46.0%, respectively) compared to the control (11.1% and 17.5%, respectively), and BBP caused damage to microfilaments and cortical granules (CGs). In addition, oocyte exposure to BBP induced impaired mitochondrial function and disrupted mitochondrial integrity. Silibinin is a natural active substance isolated from the seeds of Silybum marianum (L.) Gaertneri with strong antioxidant and anti-inflammatory effects. Noteworthy, we added different concentrations of silibinin (10, 20, and 50 µM) to BBP-exposed oocytes for rescue experiments, where 50 µM effectively rescued BBP-induced meiotic failure (70.6%). It also prevented the generation of excessive autophagy and apoptosis in oocytes by inhibiting the production of ROS. In a word, our results suggest that supplementation of silibinin attenuates the impaired oocyte development caused by BBP exposure，which provides a potential strategy to protect oocytes from environmental pollutants.

Silibinin alleviates inflammation-induced bone loss by modulating biological interaction between human gingival fibroblasts and monocytes.

BACKGROUND: Silibinin has shown various pharmacological effects that could be attributed to its antioxidant, anti-inflammatory, and immunoregulatory properties. However, the therapeutic potential of silibinin for periodontitis has not been investigated. METHODS: The therapeutic effects of silibinin in ligation-induced experimental periodontitis were investigated using biochemical, histological, and immunohistochemical methods. The effects of silibinin on the osteoclastogenesis of RAW264.7 cells were investigated using TRAP staining, quantitative polymerase chain reaction (qPCR), pit formation, and immunoblotting. Moreover, its effects on inflammatory cytokine production, RANKL expression, and oxidative stress in lipopolysaccharide (LPS)-stimulated human gingival fibroblasts (HGFs) were evaluated using qPCR and flow cytometry. A coculture system was established to elucidate the effects of silibinin on the crosstalk between LPS-stimulated HGFs and undifferentiated monocytes. RESULTS: Silibinin significantly reduced the alveolar bone loss, decreased the gingival inflammation and RANKL expression, and decreased the RANKL/osteoprotegerin ratio in gingival tissues in experimental periodontitis. The in vitro results showed that silibinin inhibited RANKL-induced osteoclast differentiation and function of RAW264.7 cells and suppressed RANKL-induced nuclear factor of activated T cells 1 (NFATc1) induction and translocation through the nuclear factor-κB and mitogen-activated protein kinase signaling pathways. Silibinin decreased the inflammatory cytokine level and oxidative stress production in LPS-stimulated HGFs; significantly suppressed membrane-bound RANKL expression on LPS-stimulated HGFs; and significantly disrupted TRAP+ cell differentiation in the coculture system. CONCLUSIONS: Silibinin effectively inhibits inflammation-induced bone loss in experimental periodontitis based on the regulation of stimulated HGFs by inhibiting the expression of inflammatory and osteoclastogenic mediators. Collectively, targeting the inflamed HGF resolution that mediates osteogenesis may use silibinin as a potential drug-repurposing candidate for modulating alveolar bone destruction in periodontitis. SUMMARY: Silibinin effectively inhibits inflammation-induced bone loss in experimental periodontitis based on the regulation of stimulated HGFs by inhibiting the expression of inflammatory and osteoclastogenic mediators.

Inhibition of UGT1A1*1 and UGT1A1*6 catalyzed glucuronidation of SN-38 by silybins.

UGT1A1 is the main enzyme that catalyzes the metabolic elimination and detoxification of SN-38, the active form of the drug irinotecan. Milk thistle products have been used widely to protect the liver from injury associated with the use of chemotherapeutic agents. To evaluate whether SN-38 metabolism can be affected by milk thistle products, the inhibitory effects of silybins on UGT1A1*1 and UGT1A1*6 were evaluated in the present investigation. Both silybin A and silybin B potently inhibited SN-38 glucuronidation catalyzed by UGT1A1*1 or UGT1A1*6. It was noteworthy that silybin A and silybin B showed synergistic effect in UGT1A1*1 microsomes at concentration around IC50, while additive effect in UGT1A1*6. According to the predicted AUCi/AUC ratios (the ratio of the area under the plasma concentration-time curve of SN-38 in the presence and absence of silybins), the coadministration of irinotecan and several milk thistle products, including silybin-phosphatidylcholine complex, two Legalon capsules, four Silymarin tablets or four Liverman capsules, may lead to clinically significant herb-drug interactions (HDI) via UGT1A1 inhibition. Meanwhile, Rgut values were much higher than 11 in all the groups, indicating potential HDI due to intestinal UGT1A1 inhibition.