Lipid peroxidation and irreversible damage in the rat hepatocyte model. Protection by the silybin-phospholipid complex IdB 1016

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.

The food plant Silybum marianum (L.) Gaertn.: Phytochemistry, Ethnopharmacology and clinical evidence

ETHNOPHARMACOLOGICAL RELEVANCE

Silybum marianum (L.) Gaertn. or Milk thistle is a medicinal plant native to Northern Africa, Southern Europe, Southern Russia and Anatolia. It also grows in South Australia, North and South America. In traditional knowledge, people have used S. marianum for liver disorders such as hepatitis, liver cirrhosis and gallbladder diseases. The main active compound of the plant seeds is silymarin, which is the most commonly used herbal supplement in the United States for liver problems. Nowadays, S. marianum products are available as capsules, powders, and extracts.

AIM OF STUDY

The aim of our study is to draw a more comprehensive overview of the traditional heritage, pharmacological benefits and chemical fingerprint of S. marianum extracts and metabolites; as well as their metabolism and bioavailability.

MATERIALS AND METHODS

An extensive literature search has been conducted using relavant keywords and papers with rationale methodology and robust data were selected and discussed. Studies involving S. marianum or its main active ingredients with regards to hepatoprotective, antidiabetic, cardiovascular protection, anticancer and antimicrobial activities as well as the clinical trials performed on the plant, were discussed here.

RESULTS

S. marianum was subjected to thousands of ethnopharmacological, experimental and clinical investigations. Although, the plant is available for use as a dietary supplement, the FDA did not yet approve its use for cancer therapy. Nowadays, clinical investigations are in progress where a global evidence of its real efficiency is needed.

CONCLUSION

S. marianum is a worldwide used herb with unlimited number of investigations focusing on its benefits and properties, however, little is known about its clinical efficiency. Moreover, few studies have discussed its metabolism, pharmacokinetics and bioavailability, so that all future studies on S. marianum should focus on such areas.

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 potential of Malvaviscus arboreus against carbon tetrachloride-induced liver injury in rats

Malvaviscus arboreus Cav. is a medicinal plant belonging to family Malvaceae with both ethnomedical and culinary value; however, its phytochemical and biological profiles have been scarcely studied. Accordingly, this work was designed to explore the chemical composition and the hepatoprotective potential of M. arboreus against carbon tetrachloride (CCl4)-induced hepatotoxicity. The total extract of the aerial parts and its derived fractions (petroleum ether, dichloromethane, ethyl acetate, and aqueous) were orally administered to rats for six consecutive days, followed by injection of CCl4 (1:1 v/v, in olive oil, 1.5 ml/kg, i.p.) on the next day. Results showed that the ethyl acetate and dichloromethane fractions significantly alleviated liver injury in rats as indicated by the reduced levels of alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total bilirubin (TB), and malondialdehyde (MDA), along with enhancement of the total antioxidant capacities of their livers, with the maximum effects were recorded by the ethyl acetate fraction. Moreover, the protective actions of both fractions were comparable to those of silymarin (100 mg/kg), and have been also substantiated by histopathological evaluations. On the other hand, liquid chromatography-high resolution electrospray ionization mass spectrometry (LC‒HR‒ESI‒MS) metabolomic profiling of the crude extract of M. arboreus aerial parts showed the presence of a variety of phytochemicals, mostly phenolics, whereas the detailed chemical analysis of the most active fraction (i.e. ethyl acetate) resulted in the isolation and identification of six compounds for the first time in the genus, comprising four phenolic acids; β-resorcylic, caffeic, protocatechuic, and 4-hydroxyphenylacetic acids, in addition to two flavonoids; trifolin and astragalin. Such phenolic principles, together with their probable synergistic antioxidant and liver-protecting properties, seem to contribute to the observed hepatoprotective potential of M. arboreus.

A Long-term Treatment with Silybin in Patients with Non-alcoholic Steatohepatitis Stimulates Catalase Activity in Human Endothelial Cells

AIM

To compare levels of oxidative stress markers in patients' sera with non-alcoholic steatohepatitis (NASH) treated for 12 months (T₁₂) with silybin conjugated with phosphatidylcholine (Realsil®) (R) or placebo (P) and investigate oxidative stress responses in human endothelial cells conditioned with patients' sera.

PATIENTS AND METHODS

We recruited twenty-seven patients with histological NASH. We measured thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD) and catalase (CAT) activities in human endothelial cells conditioned with patients' sera exposed or not to H₂O₂ Results: We found in decreased-TBARS patients' sera, at T₁₂, a decrease of alanine aminotransferase (p=0.038), transforming growth factor-beta (p=0.009) and procollagen I (p=0.001). By dividing patients into two groups, increased (P-I/R-I) and decreased TBARS (P-II/R-II) at T₁₂ compared to T₀, we found an increased CAT activity in conditioned endothelial cells at T12 in both groups (p=0.05 and p=0.001, respectively).

CONCLUSION

Realsil® may be effective against endothelial dysfunction by stimulating the cellular antioxidant defense.

Phytosomal curcumin: A review of pharmacokinetic, experimental and clinical studies

Curcumin, a hydrophobic polyphenol, is the principal constituent extracted from dried rhizomes of Curcuma longa L. (turmeric). Curcumin is known as a strong anti-oxidant and anti-inflammatory agent that has different pharmacological effects. In addition, several studies have demonstrated that curcumin is safe even at dosages as high as 8g per day; however, instability at physiological pH, low solubility in water and rapid metabolism results in a low oral bioavailability of curcumin. The phytosomal formulation of curcumin (a complex of curcumin with phosphatidylcholine) has been shown to improve curcumin bioavailability. Existence of phospholipids in phytosomes leads to specific physicochemical properties such as amphiphilic nature that allows dispersion in both hydrophilic and lipophilic media. The efficacy and safety of curcumin phytosomes have been shown against several human diseases including cancer, osteoarthritis, diabetic microangiopathy and retinopathy, and inflammatory diseases. This review focuses on the pharmacokinetics as well as pharmacological and clinical effects of phytosomal curcumin.

Silymarin induces cyclin D1 proteasomal degradation via its phosphorylation of threonine-286 in human colorectal cancer cells

Silymarin from milk thistle (Silybum marianum) plant has been reported to show anti-cancer, anti-inflammatory, antioxidant and hepatoprotective effects. For anti-cancer activity, silymarin is known to regulate cell cycle progression through cyclin D1 downregulation. However, the mechanism of silymarin-mediated cyclin D1 downregulation still remains unanswered. The current study was performed to elucidate the molecular mechanism of cyclin D1 downregulation by silymarin in human colorectal cancer cells. The treatment of silymarin suppressed the cell proliferation in HCT116 and SW480 cells and decreased cellular accumulation of exogenously-induced cyclin D1 protein. However, silymarin did not change the level of cyclin D1 mRNA. Inhibition of proteasomal degradation by MG132 attenuated silymarin-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in the cells treated with silymarin. In addition, silymarin increased phosphorylation of cyclin D1 at threonine-286 and a point mutation of threonine-286 to alanine attenuated silymarin-mediated cyclin D1 downregulation. Inhibition of NF-κB by a selective inhibitor, BAY 11-7082 suppressed cyclin D1 phosphorylation and downregulation by silymarin. From these results, we suggest that silymarin-mediated cyclin D1 downregulation may result from proteasomal degradation through its threonine-286 phosphorylation via NF-κB activation. The current study provides new mechanistic link between silymarin, cyclin D1 downregulation and cell growth in human colorectal cancer cells.

Inhibitory effect of silybin on pharmacokinetics of imatinib in vivo and in vitro

The objective of this work was to investigate the effect of orally administered silybin on the pharmacokinetics of imatinib in rats and the metabolism of imatinib in human liver microsome and rat liver microsomes. Eighteen healthy male SD rats were randomly divided into 3 groups: group A (control group), group B (received multiple doses of 50 mg·kg−1 silybin for 15 consecutive days), and group C (received a single dose of 50 mg·kg−1 silybin). A single dose of imatinib was administered orally 30 min after administration of silybin (50 mg·kg−1). Imatinib plasma levels were measured by UPLC-MS/MS, and pharmacokinetic parameters were calculated by DAS 3.0 software (Bontz Inc., Beijing, China). In addition, human and rat liver microsome were performed to determine the effects of silybin metabolism of imatinib in vitro. The multiple doses or single dose of 50 mg·kg−1 silybin significantly decreased the area under the curve (0-t) of imatinib (p < 0.01). And the half-life (t1/2) of imatinib is significantly increased (p < 0.05 and p < 0.01, respectively). Also, silybin showed inhibitory effect on human and rat microsomes, the IC50 of silybin were 26.42 μmol·L−1 and 49.12 μmol·L−1 in human and rat liver microsomes, respectively. These results indicate that more attention should be paid to when imatinib is administrated combined with silybin.

Review of natural products with hepatoprotective effects

The liver is one of the most important organs in the body, performing a fundamental role in the regulation of diverse processes, among which the metabolism, secretion, storage, and detoxification of endogenous and exogenous substances are prominent. Due to these functions, hepatic diseases continue to be among the main threats to public health, and they remain problems throughout the world. Despite enormous advances in modern medicine, there are no completely effective drugs that stimulate hepatic function, that offer complete protection of the organ, or that help to regenerate hepatic cells. Thus, it is necessary to identify pharmaceutical alternatives for the treatment of liver diseases, with the aim of these alternatives being more effective and less toxic. The use of some plants and the consumption of different fruits have played basic roles in human health care, and diverse scientific investigations have indicated that, in those plants and fruits so identified, their beneficial effects can be attributed to the presence of chemical compounds that are called phytochemicals. The present review had as its objective the collecting of data based on research conducted into some fruits (grapefruit, cranberries, and grapes) and plants [cactus pear (nopal) and cactus pear fruit, chamomile, silymarin, and spirulina], which are consumed frequently by humans and which have demonstrated hepatoprotective capacity, as well as an analysis of a resin (propolis) and some phytochemicals extracted from fruits, plants, yeasts, and algae, which have been evaluated in different models of hepatotoxicity.

Treatment with essential oil of Achyrocline satureioides in rats infected with Trypanosoma evansi: relationship between protective effect and tissue damage

The aim of this study was to evaluate the effects of treatment with free and nanoencapsulated essential oil of Achyrocline satureioides on trypanosomosis and its oxidative/antioxidants variables in liver and kidney of rats infected experimentally with Trypanosoma evansi. For that, 48 rats were divided into six groups (A-F), eight animals each group. Groups A, C and D were composed of uninfected animals, while animals in groups B, E and F were inoculated intraperitoneally with T. evansi. Groups A and B were used as controls, negative and positive, respectively. Groups C and E receive oil (orally), as well as the animals in groups D and F were treated with nanoencapsulated essential oil. The treatment was not able to eliminate the parasites, but it remained the levels of parasitemia low. The carbonyl levels in liver and kidney did not differ between groups. Infected animals (group B) showed an increase in the TBARS levels and a decrease in the CAT activity and NPSH levels in liver and kidney, compared with the same parameters in the control (group A). Treatment with A. satureioides (groups C and D) did not influence the TBARS levels and CAT activity in the liver, but it increased the CAT activity in kidneys of the animals of group C. NPSH levels decreased in liver in the groups treated with nanoencapsulated essential oil (groups D and F). An interesting result observed was that the animals infected and then treated with essential oil of A. satureioides (groups E and F) did not differ from animals of group A for TBARS, CAT and NPSH, unlike what happened with the animals of group B. Therefore, the treatment with essential oil did not eliminate the parasites from the bloodstream, but it reduced the number of trypanosomes, mainly by its nanoencapsulated form. The same occurred with the lipid peroxidation in the liver. However, the treatments reduced the oxidative damage, and it led to the activation of the antioxidant enzymes. We believe that the association of this natural product with a trypanocidal drug may enhance its curative effect.

Silibinin regulates matrix metalloproteinase 3 (stromelysine1) gene expression, hexoseamines and collagen production during rat skin wound healing

Silibinin (SB), a flavonoid isolated from the milk thistle, Silybum marianum, has been shown to exhibit protective effects against skin damage. The objective of the present study was to investigate the effect of topical application of SB on levels of stromelysine 1 (STM1) gene expression, acetyl hexoseamines and collagen production during skin wound healing. Full-thickness skin wounds were topically treated with 10% and 20% SB extract in acetonitril:olive oil (AOO) (4:1) for 30 days, and expression level of STM1 transcript, n-acetyl glucoseamine (NAGLA), n-acetyl galactoseamine (NAGAA) and collagen contents were analyzed on the 10th, 20th and 30th days post wounding. SB in dose- and time-dependent manner accelerated wound closure time and increased levels of STM1 mRNA, hydroxyproline, NAGLA and NAGAA compared to the untreated and vehicle (AOO)-treated rats. The current study provides evidence that SB, by increasing STM1 gene expression and extracellular matrix constituents including glycosaminoglycans and collagen contents, promotes a faster wound healing process and can be used as a healing agent in future.

Silymarin loaded liposomes for hepatic targeting: in vitro evaluation and HepG2 drug uptake

Silymarin has hepatoprotective properties and is used in treatment of various liver diseases, but its bioavailability from oral products is very poor. In order to overcome its poor oral bioavailability we have prepared silymarin loaded hepatic targeting liposomes suitable for parenteral administration. The liposomal formulations were composed of hydrogenated soy phosphatidylcholine and cholesterol with or without distearoylphosphoethanolamine-(polyethyleneglycol)-2000 and various amounts of β-sitosterol β-D-glucoside (Sito-G) as the hepatic targeting moiety. Increasing the amount of Sito-G in the liposomes gradually decreased drug encapsulation efficiencies from ∼70% to ∼60%; still showing promising drug encapsulation efficiencies. Addition of Sito-G to non-PEGylated liposomes clearly affected their drug release profiles and plasma protein interactions, whereas no effect on these was seen for the PEGylated liposomes. Non-PEGylated liposomes with 0.17 M ratio of Sito-G exhibited the highest cellular drug uptake of 37.5% for all of the studied liposome formulations. The highest cellular drug uptake in the case of PEGylated liposomes was 18%, which was achieved with 0.17 and 0.33 M ratio of added Sito-G. The liposome formulations with the highest drug delivery efficacy in this study showed hemolytic activities around 12.7% and were stable for at least 2 months upon storage in 20 mM HEPES buffer (pH 7.4) containing 1.5% Polysorbate 80 at 4 °C and room temperature. These results suggest that the Sito-G containing liposomes prepared in this work have hepatic targeting capability and that they are promising candidates for delivering silymarin to the liver.

DPPH free radical scavenging activity and phenotypic difference in hepatoprotective plant (Silybum marianum L.)

Silybum marianum L. is medicinally important for its active principle component silymarin. Silymarin regenerates damaged hepatic tissues. On the basis of such regenerative properties, the radical scavenging activity (1,1-diphenyl-2-picrylhydrazyl (DPPH)) of different tissues and the phenotypic difference of the hepatoprotective species, S. marianum L. were evaluated. There was less phenotypic difference in purple and white varieties of S. marianum. Assay of the antioxidant potential of different parts of the plant revealed that significantly higher activity (78.2%) was observed in seeds of the purple flowering plant than seeds of white flowering plant (49%) after different time intervals. Young leaves collected from white flowering plant exhibit 64.8% activity, which is higher than the purple flowering plant (55.1%). Significantly, same activity was observed in mature leaves of white (52%) and purple flowering plants (50%). The main stem collected from both the varieties exhibits similar activity from 50 to 52%. A 67.2% activity was recorded for mature roots of white flowering plant followed by roots of the purple variety (65%). The present study revealed that seeds and roots of both the varieties scavenge and detoxify more DPPH free radicals than other plant parts and can be used as a source of natural antioxidants and food additives.

Anti-HBV agents derived from botanical origin

There are 350,000 hepatitis B virus (HBV) carriers all over the world. Chronic HBV infection is at a high risk of developing liver cirrhosis and hepatocelluar carcinoma (HCC), and heavily threatened people's health. Two kinds of drugs approved by FDA for anti-HBV therapy are immunomodulators (interferon α, pegylated-interferon α) and nucleos(t)ide analogues (lamivudine, adefovir dipivoxil, entecavir, telbivudine, and tenofovir disoproxil fumarate). These drugs have been proved to be far from being satisfactory due to their low specificity, side effects, and high rate of drug resistance. There is an urgent need to discover and develop novel effective anti-HBV drugs. With vast resources, various structures, diverse biological activities and action mechanisms, as well as abundant clinical experiences, botanical agents become a promising source of finding new anti-HBV drugs. This review summarizes the recent research and development of anti-HBV agents derived from botanical origin on their sources and active components, inhibitory effects and possible toxicities, as well as action targets and mechanisms, and also addresses the advantages and the existing shortcomings in the development of botanical inhibitors. This information may not only broaden the knowledge of anti-HBV therapy, and offer possible alternative or substitutive drugs for CHB patients, but also provides considerable information for developing new safe and effective anti-HBV drugs.

Effects of Phyllanthus acidus (L.) Skeels fruit on carbon tetrachloride-induced acute oxidative damage in livers of rats and mice

OBJECTIVE

The present study was undertaken with a view to validate the traditional use of Phyllanthus acidus (L.) Skeels fruit as a hepatoprotective agent.

METHODS

The 70% ethanolic extract of P. acidus fruit (100, 200 and 400 mg/kg, p.o.), and reference drug silymarin (100 mg/kg, p.o.) were given to rats of different groups respectively once a day for 5 d and the carbon tetrachloride (CCl4) (2 mL/kg, subcutaneously) was given on days 2 and 3. Serum levels of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin (TB) and total protein (TP) were assessed along with liver histopathological examination. The effects on oxidative stress markers such as lipid peroxidation (LPO), reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were also assessed in liver tissue homogenate to evaluate in vivo antioxidant activity. In addition, the effects on hexobarbitone-induced sleeping time were observed and the free radical-scavenging potential was determined by using 2, 2-diphenyl-1-picrylhydrazil (DPPH) in mice.

RESULTS

P. acidus extracts and silymarin exhibited a significant hepatoprotective effect as evident from the decreases of serum AST, ALT and ALP levels and LPO and increases in the levels of TP, GSH, SOD, CAT, and GPx compared with control group (P<0.01 or P<0.05). The biochemical results were supplemented with results of histopathological sections of the liver tissues. P. acidus extracts considerably shortened the duration of hexobarbitone-induced sleeping time in mice compared with control group (P<0.01) and showed remarkable DPPH-scavenging activity.

CONCLUSION

The present findings suggest that the hepatoprotective effect of P. acidus against CCl4-induced oxidative damage may be related to its antioxidant and free radical-scavenging potentials.

Silybin and the liver: From basic research to clinical practice

Herbal products are increasingly used, mainly in chronic liver disease. Extracts of milk thistle, Silymarin and silybin, are the most prescribed natural compounds, with different indications, but with no definitive results in terms of clinical efficacy. This review analyzes the available studies on the effects of the purified product silybin, both as a free and a conjugated molecule, on liver cells or on experimentally induced liver damage, and in patients with liver disease. We searched PUBMED for articles pertaining to the in vitro and in vivo effects of silybin, its antifibrotic, anti-inflammatory, and antioxidant properties, as well as its metabolic effects, combined with the authors’ own knowledge of the literature. Results indicate that the bioavailability of silybin phytosome is higher than that of silymarin and is less influenced by liver damage; silybin does not show significant interactions with other drugs and at doses < 10 g/d has no significant side effects. Experimental studies have clearly demonstrated the antifibrotic, antioxidant and metabolic effects of silybin; previous human studies were insufficient for confirming the clinical efficacy in chronic liver disease, while ongoing clinical trials are promising. On the basis of literature data, silybin seems a promising drug for chronic liver disease.

Silybin inhibits interleukin-1β-induced production of pro-inflammatory mediators in canine hepatocyte cultures

Hepatocytes are highly susceptible to cytokine stimulation and are fundamental to liver function. We established primary canine hepatocyte cultures to study effects of anti-inflammatory agents with hepatoprotective properties. Hepatocyte cultures were incubated with control media alone, silybin (SB), or the more bioavailable silybin-phosphatidylcholine complex (SPC), followed by activation with interleukin-1 beta (IL-1β; 10 ng/mL). Inflammatory response was measured by prostaglandin E2 (PGE(2) ), interleukin-8 (IL-8), and monocyte chemotactic protein-1 (MCP-1) production and also nuclear factor-kappa B (NF-κB) translocation. Hepatocyte cultures continued production of the phenotypic marker albumin for more than 7 days in culture. IL-1β exposure increased PGE(2) , IL-8, and MCP-1 production, which was paralleled by NF-κB translocation from the cytoplasm to the nucleus. Pretreatment with SB and SPC significantly inhibited IL-1β-induced production of pro-inflammatory markers and attenuated NF-κB nuclear translocation. We demonstrate for the first time that primary canine hepatocyte cultures can be maintained in culture without phenotypic loss. The observation that hepatocyte cultures respond to pro-inflammatory IL-1β activation indicates hepatocytes as primary cellular targets of extrinsic IL-1β. The ability of SB and SPC to inhibit hepatocyte culture activation by IL-1β reinforces the notion of their hepatoprotective effects. Our primary canine hepatocyte culture model facilitates identification of hepatoprotective agents and their mechanism of action.

Applications of novel drug delivery system for herbal formulations

Over the past several years, great advances have been made on development of novel drug delivery systems (NDDS) for plant actives and extracts. The variety of novel herbal formulations like polymeric nanoparticles, nanocapsules, liposomes, phytosomes, nanoemulsions, microsphere, transferosomes, and ethosomes has been reported using bioactive and plant extracts. The novel formulations are reported to have remarkable advantages over conventional formulations of plant actives and extracts which include enhancement of solubility, bioavailability, protection from toxicity, enhancement of pharmacological activity, enhancement of stability, improved tissue macrophages distribution, sustained delivery, and protection from physical and chemical degradation. The present review highlights the current status of the development of novel herbal formulations and summarizes their method of preparation, type of active ingredients, size, entrapment efficiency, route of administration, biological activity and applications of novel formulations.

In vitro effects of plant and mushroom extracts on immunological function of chicken lymphocytes and macrophages

1. The present study was conducted to examine the effects of organic extracts from milk thistle (Silybum marianum), turmeric (Curcuma longa), reishi mushroom (Ganoderma lucidum), and shiitake mushroom (Lentinus edodes) on innate immunity and tumor cell viability. 2. Innate immunity was measured by lymphocyte proliferation and nitric oxide production by macrophages, and the inhibitory effect on tumor cell growth was assessed using a non-radioactive assay. For measuring the cytokine levels in the HD11 macrophages which were treated with extracts of turmeric or shiitake mushroom, the levels of mRNAs for interferon-alpha (IFN- alpha), interleukin-1beta (IL-1beta), IL-6, IL-12, IL-15, IL-18, and tumor necrosis factor superfamily 15 (TNFSF15) were quantified by real time RT-PCR. 3. In vitro culture of chicken spleen lymphocytes with extracts of milk thistle, turmeric, and shiitake and reishi mushrooms induced significantly higher cell proliferation compared with the untreated control cells. Stimulation of macrophages with extracts of milk thistle and shiitake and reishi mushrooms, but not turmeric, resulted in robust nitric oxide production to levels that were similar with those induced by recombinant chicken interferon-gamma. All extracts uniformly inhibited the growth of chicken tumor cells in vitro at the concentration of 6.3 through 100 microg/ml. Finally, the levels of mRNAs encoding IL-1beta, IL-6, IL-12, IL-18, and TNFSF15 were enhanced in macrophages that were treated with extracts of turmeric or shiitake mushroom compared with the untreated control. 4. These results document the immunologically-based enhancement of innate immunity in chickens by extracts of plants and mushrooms with known medicinal properties in vitro. In vivo studies are being planned to delineate the cellular and molecular mechanisms responsible for their mechanism of action.

A silybin-phospholipid complex prevents mitochondrial dysfunction in a rodent model of nonalcoholic steatohepatitis

Mitochondrial dysfunction and oxidative stress are determinant events in the pathogenesis of nonalcoholic steatohepatitis. Silybin has shown antioxidant, anti-inflammatory, and antifibrotic effects in chronic liver disease. We aimed to study the effect of the silybin-phospholipid complex (SILIPHOS) on liver redox balance and mitochondrial function in a dietary model of nonalcoholic steatohepatitis. To accomplish this, glutathione oxidation, mitochondrial oxygen uptake, proton leak, ATP homeostasis, and H(2)O(2) production rate were evaluated in isolated liver mitochondria from rats fed a methionine- and choline-deficient (MCD) diet and the MCD diet plus SILIPHOS for 7 and 14 weeks. Oxidative proteins, hydroxynonenal (HNE)- and malondialdehyde (MDA)-protein adducts, and mitochondrial membrane lipid composition were also measured. Treatment with SILIPHOS limited glutathione depletion and mitochondrial H(2)O(2) production. Moreover, SILIPHOS preserved mitochondrial bioenergetics and prevented mitochondrial proton leak and ATP reduction. Finally, SILIPHOS limited the formation of HNE- and MDA-protein adducts. In conclusion, SILIPHOS is effective in preventing severe oxidative stress and preserving hepatic mitochondrial bioenergetics in nonalcoholic steatohepatitis induced by the MCD diet. The modifications of mitochondrial membrane fatty acid composition induced by the MCD diet are partially prevented by SILIPHOS, conferring anti-inflammatory and antifibrotic effects. The increased vulnerability of lipid membranes to oxidative damage is limited by SILIPHOS through preserved mitochondrial function.

Enhancing bioavailability and hepatoprotective activity of andrographolide from Andrographis paniculata, a well-known medicinal food, through its herbosome

BACKGROUND

Andrographis paniculata is a health food used extensively in Southeast Asia, India and China and contains the pharmacologically important phytochemical andrographolide. Although andrographolide has antihepatotoxic activity, its bioavailability from A. paniculata is restricted by its rapid clearance and high plasma protein binding. The aim of this study was to formulate a herbosome of andrographolide with a naturally occurring phospholipid in order to enhance the bioavailability and hepatoprotective activity of andrographolide in rats.

RESULTS

Andrographolide herbosome equivalent to 25 and 50 mg kg(-1) andrographolide significantly protected the liver of rats, restoring hepatic enzyme activities with respect to carbon tetrachloride-treated animals (P < 0.05 and P < 0.01 respectively). The rat plasma concentration of andrographolide obtained from the complex equivalent to 25 mg kg(-1) andrographolide (C(max) = 9.64 microg mL(-1)) was higher than that obtained from 25 mg kg(-1) andrographolide (C(max) = 6.79 microg mL(-1)), and the complex maintained its effective plasma concentration for a longer period of time.

CONCLUSION

The results proved that the andrographolide complex produced by this method has better bioavailability and hence improved hepatoprotective activity compared with andrographolide at the same dose. Andrographolide complexation is therefore helpful in solving the problem of rapid clearance and low elimination half-life associated with andrographolide from A. paniculata.

Antioxidant and antiviral activities of silybin fatty acid conjugates

Two selective acylation methods for silybin esterification with long-chain fatty acids were developed, yielding a series of silybin 7-O- and 23-O-acyl-derivatives of varying acyl chain lengths. These compounds were tested for their antioxidant (inhibition of lipid peroxidation and DPPH-scavenging) and anti-influenza virus activities. The acyl chain length is an important prerequisite for both biological activities, as they improved with increasing length of the acyl moiety.

Cosmeceuticals and silibinin

Cosmeceuticals are used for nourishing and improving the appearance of the skin and are also documented as effective agents for treating various dermatologic conditions. Cosmeceutical preparations from herbal origin are most popular among consumers because these agents are mostly nontoxic and possess strong antioxidant activity. Because oxidative stress is one of the major mechanisms for skin aging and dermatologic conditions, phytochemicals with proven antioxidant activity, such as silibinin, could be useful for treating many dermatologic conditions as well as skin aging. Silibinin is a flavonolignan compound from Silybum marianum (milk thistle plant) that possesses strong antioxidant activity and also modulates many molecular changes caused by xenobiotics and ultraviolet radiation to protect the skin. This contribution reviews the evidence generated from laboratory studies to support the scientific rationale for the effective use of silibinin in cosmeceutical preparations.

Supramolecular phospholipids-polyphenolics interactions: the PHYTOSOME strategy to improve the bioavailability of phytochemicals

The poor and/or erratic oral bioavailability of polyphenolics can be improved using the PHYTOSOME delivery system, a strategy that enhances the rate and the extent of solubilization into aqueous intestinal fluids and the capacity to cross biomembranes. Phospholipids show affinity for polyphenolics, and form supramolecular adducts having a definite stoichiometry. This article reviews the preparation and characterization of PHYTOSOME complexes and their activity in various medicinal (cardiovascular, anti-inflammatory, hepatoprotective, anticancer) and cosmetic (skin aging) realms of application.

Silybin, a component of sylimarin, exerts anti-inflammatory and anti-fibrogenic effects on human hepatic stellate cells

BACKGROUND/AIMS

Hepatic fibrogenesis, a consequence of chronic liver tissue damage, is characterized by activation of the hepatic stellate cells (HSC). Silybin has been shown to exert anti-fibrogenic effects in animal models. However, scant information is available on the fine cellular and molecular events responsible for this effect. The aim of this study was to assess the mechanisms regulating the anti-fibrogenic and anti-inflammatory activity of Silybin.

METHODS

Experiments were performed on HSC isolated from human liver and activated by culture on plastic.

RESULTS

Silybin was able to inhibit dose-dependently (25-50 microM) growth factor-induced pro-fibrogenic actions of activated human HSC, including cell proliferation (P < 0.001), cell motility (P < 0.001), and de novo synthesis of extracellular matrix components (P < 0.05). Silybin (25-50 microM), inhibited the IL-1-induced synthesis of MCP-1 (P < 0.01) and IL-8 (P < 0.01) showing a potent anti-inflammatory activity. Silybin exerts its effects by directly inhibiting the ERK, MEK and Raf phosphorylation, reducing the activation of NHE1 (Na+/H+ exchanger, P < 0.05) and the IkBalpha phosphorylation. In addition, Silybin was confirmed to act as a potent anti-oxidant agent.

CONCLUSION

The results of the study provide molecular insights into the potential therapeutic action of Silybin in chronic liver disease. This action seems to be mostly related to a marked inhibition of the production of pro-inflammatory cytokines, a clear anti-oxidant effect and a reduction of the direct and indirect pro-fibrogenic potential of HSC.

Drug-drug interactions of silymarin on the perspective of pharmacokinetics

Silymarin, which is extracted from the milk thistle (Silybum marianum), has been used for centuries for treating hepatic disorders and its hepatoprotective effects have been known for hundreds of years. Silymarin is a mixture of polyphenoic flavonoids, which include silibinin (silybin A and silybin B), isosilyin A and B, silychristin A and B, silydianin and other phenol compounds. The pharmacokinetics of silibinin shows fast absorption and elimination. Silymarin undergoes phase I and phase II metabolism, especially phase II conjugation reactions, it undergoes multiple conjugation reactions, and is primarily excreted into bile and urine. Silymarin has a good safety profile, but little is known regarding its potential for drug interaction. Silymarin has limited effect on the pharmacokinetics of several drugs in vivo; despite silymarin decreasing the activity of cytochrome P-450 (CYPs) enzymes, UDP-glucuronosyltransferase (UGT) enzyme, and reducing P-glycoprotein (P-gp) transport. Health-care practitioners should caution patients against co-administration of silymarin and pharmaceutical drugs.

Topical application of silymarin reduces chemical-induced irritant contact dermatitis in BALB/c mice

Irritant contact dermatitis (ICD) is a non-allergic local inflammatory reaction of a skin and one of the most frequent occupational health problems. Silymarin has been clinically used in Europe for a long time to treat liver diseases and also known to have anti-cancer and anti-inflammatory activities. In the present study, we report that topical application of silymarin reduces chemical-induced ICD. Topical application of 2,4-dinitrochlorobenzene (DNCB) induced an ear swelling in BALB/c mice and silymarin suppressed DNCB-induced increase in ear thickness. Prophylactic and therapeutic application of silymarin showed similar effect on DNCB-induced increase in ear thickness and skin water content. In addition, phobor ester- or croton oil-induced increase in ear thickness was also inhibited by silymarin treatment. Silymarin also blocked neutrophil accumulation into the ear induced by these irritants. Further study demonstrated that DNCB-induced tumor necrosis factor-alpha (TNF-alpha) expression in mouse ear was suppressed by silymarin. DNCB-induced expression of KC, one of the main attractors of neutrophil in mice, and adhesion molecules, including intercellular adhesion molecule-1 (ICAM-1) and E-selectin in mouse ear were also inhibited by silymarin. Moreover, TNF-alpha-induced expression of cytokines, such as TNF-alpha and IL-1beta, and a chemokine, IL-8, were suppressed by silymarin treatment in human keratinocyte cell line, HaCaT. Silymarin also blocked TNF-alpha- and DNCB-induced NF-kappaB activation in HaCaT. Collectively, these results demonstrate that topically applied silymarin inhibits chemical-induced ICD in mice and this might be mediated, at least in part, by blocking NF-kappaB activation and consequently inhibiting the expression of cytokines and adhesion molecules.

Protective effect of silymarin on oxidative stress in rat brain

Brain is susceptible to oxidative stress and it is associated with age-related brain dysfunction. Previously, we have pointed out a dramatic decrease of glutathione levels in the rat brain after acetaminophen (APAP) oral administration overdose. Silymarin (SM) is a mixture of bioactive flavonolignans isolated from Silybum marianum (L.) Gaertn., employed usually in the treatment of alcoholic liver disease and as anti-hepatotoxic agent in humans. In this study, we have evaluated the effect of SM on enzymatic and non enzymatic antioxidant defensive systems in rat brain after APAP-induced damage. Male albino Wistar rats were treated with SM (200 mg/kg/die orally) for three days, or with APAP single oral administration (3 g/kg) or with SM (200 mg/kg/die orally) for 3 days and APAP single oral administration (3 g/kg) at third day. Successively the following parameters were measured: reduced and oxidized glutathione (GSH and GSSG), ascorbic acid (AA), enzymatic activity variations of superoxide dismutase (SOD) and malondialdehyde levels (MDA). Our results showed a significant decrease of GSH levels, AA levels and SOD activity and an increase of MDA and GSSG levels after APAP administration. After SM administration GSH and AA significantly increase and SOD activity was significantly enhanced. In the SM+APAP group, GSH values significantly increase and the others parameters remained unchanged respect to control values. These results suggest that SM may to protect the SNC by oxidative damage for its ability to prevent lipid peroxidation and replenishing the GSH levels.

(+)-Silybin, a pharmacologically active constituent of Silybum marianum: fragmentation studies by atmospheric pressure chemical ionization quadrupole time-of-flight tandem mass spectrometry

The fragmentation behavior of (+)-silybin (1) and (+)-deuterosilybin (2), as well as of their flavanone-3-ol-type building blocks, such as 3,5,7-trihydroxy-2-phenyl-4-chromanone (3) and 2-(1,4-benzodioxolanyl)-3,5,7-trihydroxy-4-chromanone (4), were investigated by atmospheric pressure chemical ionization quadropole time-of-flight tandem mass spectrometry in the positive ion mode (APCI(+)-QqTOF MS/MS). The product ion spectra of the protonated molecules of 1 revealed a rather complicated fragmentation pattern with product ions originating from consecutive and competitive loss of small molecules such as H2O, CO, CH2O, CH3OH and 2-methoxyphenol, along with the A+- and B+-type ions arising from the cleavage of the C-ring of the flavanone-3-ol moiety. The elucidation of the fragmentation behavior of 1 was facilitated by acquiring information on the fragmentation characteristics of the flavanone-3-ol moieties and 2. The capability of the accurate mass measurement on the quadrupole time-of-flight mass spectrometer allowed us to determine the elemental composition of each major product ion. Second-generation product ion spectra obtained by combination of in-source collision induced dissociation (CID) with selective CID (pseudo-MS(3)) was also helpful in elaborating the fragmentation pathways and mechanism. Based on the experimental results, a fragmentation mechanism as well as fragmentation pathways for 1 and its flavanone-3-ol building blocks (3, 4) are proposed and discussed.

Effects of the plant flavonoids silymarin and quercetin on arsenite-induced oxidative stress in CHO-K1 cells

Chronic toxic effects of arsenic resulting from drinking water are a human health problem, especially in South-America and Asia. Arsenic is capable of influencing various cellular processes, causing adverse effects, including cancer. Although the exact mechanism of the action is not known, a correlation between oxidative stress, tumour promotion and arsenic exposure has been observed. We examined the effects of silymarin and quercetin, in counteracting oxidative stress produced by acute or sub-chronic sodium arsenite exposure. The stress responses to arsenite included an increase in the heat shock protein 70 kDa expression, lipid peroxidation assayed by conjugated dienes measure, and gamma-glutamyl-transpeptidase activity. We found that all these stress responses were eliminated by silymarin and quercetin in acute experiments. Both flavonoids diminished the conjugated dienes formation during sub-chronic cultures. Our results suggest that these antioxidant flavonoids, which may be easily incorporated into the diet, may afford a protective effect against arsenite-induced cytotoxicity.

Curcumin-phospholipid complex: Preparation, therapeutic evaluation and pharmacokinetic study in rats

A novel formulation of curcumin in combination with the phospholipids was developed to overcome the limitation of absorption and to investigate the protective effect of curcumin-phospholipid complex on carbon tetrachloride induced acute liver damage in rats. The antioxidant activity of curcumin-phospholipid complex (equivalent of curcumin 100 and 200 mg/kg body weight) and free curcumin (100 and 200 mg/kg body weight) was evaluated by measuring various enzymes in oxidative stress condition. Curcumin-phospholipid complex significantly protected the liver by restoring the enzyme levels of liver glutathione system and that of superoxide dismutase, catalase and thiobarbituric acid reactive substances with respect to carbon tetrachloride treated group (P < 0.05 and <0.01). The complex provided better protection to rat liver than free curcumin at same doses. Serum concentration of curcumin obtained from the complex (equivalent to 1.0 g/kg of curcumin) was higher (Cmax 1.2 microg/ml) than pure curcumin (1.0 g/kg) (Cmax 0.5 microg/ml) and the complex maintained effective concentration of curcumin for a longer period of time in rat serum. The result proved that curcumin-phospholipid complex has better hepatoprotective activity, owe to its superior antioxidant property, than free curcumin at the same dose level.

Dietary antioxidant compounds and liver health

Chronic liver damage is a widespread pathology characterized by a progressive evolution from steatosis to chronic hepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. As the oxidative stress plays a central role in liver diseases pathogenesis and progression, the use of antioxidants have been proposed as therapeutic agents, as well as drug coadjuvants, to counteract liver damage. In this work in vitro and in vivo studies, with emphasis on humans and animals experiments, have been considered and reviewed according to antioxidant typologies. Great differences emerge as far as ingested doses, bioavailability and liver ability to accumulate the various compounds. Results available up to now suggest that lycopene-rich foods could be proposed in therapeutic treatment of some liver pathologies. On the other hand contradictory results have been obtained with alpha-tocopherol, beta-carotene and trans-resveratrol. Quercetin, silymarin, esculetin and thyme and rosemary among phenolic compounds need further studies.

Silybin inactivates cytochromes P450 3A4 and 2C9 and inhibits major hepatic glucuronosyltransferases

Silybin, a major constituent of the milk thistle, is used to treat several liver disorders. Silybin inactivated purified, recombinant cytochromes P450 (P450) 3A4 and 2C9 in a mechanism-based manner. The inactivations were time-, concentration-, and NADPH-dependent. The inactivation of the 7-benzyloxy-4-(trifluoromethyl-)coumarin O-debenzylation activity (P450 3A4) was characterized by a K(I) of 32 microM, a k(inact) of 0.06 min(-1), and a t(1/2) of 14 min. Testosterone metabolism to 6-beta-hydroxytestosterone (P450 3A4) was also inactivated with a K(I) of 166 microM, a k(inact) of 0.08 min(-1), and a t(1/2) of 9 min. The 7-ethoxy-4-(trifluoromethyl)coumarin O-deethylation activity of purified human P450 2C9 was inactivated with a K(I) of 5 microM, a k(inact) of 0.14 min(-1), and a t(1/2) of 7 min. Parallel loss of heme was observed with both P450s. Activity of both P450 enzymes was not recovered after removal of silybin either by dialysis or by spin gel filtration. In addition, silybin inhibited the glucuronidation of 7-hydroxy-4-trifluoromethylcoumarin catalyzed by recombinant hepatic UDP-glucuronosyltransferases (UGTs) 1A1, 1A6, 1A9, 2B7, and 2B15, with IC(50) values of 1.4 microM, 28 microM, 20 microM, 92 microM, and 75 microM, respectively. Silybin was a potent inhibitor of UGT1A1 and was 14- and 20-fold more selective for UGT1A1 than for UGT1A9 and UGT1A6, respectively. Thus, careful administration of silybin with drugs primarily cleared by P450s 3A4 or 2C9 is advised, since drug-drug interactions cannot be excluded. The clinical significance of in vitro UGT1A1 inhibition is unknown.

Herbal modulation of P-glycoprotein

P-glycoprotein (Pgp) is a 170 kDa phosphorylated glycoprotein encoded by human MDR1 gene. It is responsible for the systemic disposition of numerous structurally and pharmacologically unrelated lipophilic and amphipathic drugs, carcinogens, toxins, and other xenobiotics in many organs, such as the intestine, liver, kidney, and brain. Like cytochrome P450s (CYP3A4), Pgp is vulnerable to inhibition, activation, or induction by herbal constituents. This was demonstrated by using an ATPase assay, purified Pgp protein or intact Pgp-expressing cells, and proper probe substrates and inhibitors. Curcumin, ginsenosides, piperine, some catechins from green tea, and silymarin from milk thistle were found to be inhibitors of Pgp, while some catechins from green tea increased Pgp-mediated drug transport by heterotropic allosteric mechanism, and St. John's wort induced the intestinal expression of Pgp in vitro and in vivo. Some components (e.g., bergamottin and quercetin) from grapefruit juice were reported to modulate Pgp activity. Many of these herbal constituents, in particular flavonoids, were reported to modulate Pgp by directly interacting with the vicinal ATP-binding site, the steroid-binding site, or the substrate-binding site. Some herbal constituents (e.g., hyperforin and kava) were shown to activate pregnane X receptor, an orphan nuclear receptor acting as a key regulator of MDR1 and many other genes. The inhibition of Pgp by herbal constituents may provide a novel approach for reversing multidrug resistance in tumor cells, whereas the stimulation of Pgp expression or activity has implication for chemoprotective enhancement by herbal medicines. Certain natural flavonols (e.g., kaempferol, quercetin, and galangin) are potent stimulators of the Pgp-mediated efflux of 7,12-dimethylbenz(a)-anthracene (a carcinogen). The modulation of Pgp activity and expression by these herb constituents may result in altered absorption and bioavailability of drugs that are Pgp substrates. This is exemplified by increased oral bioavailability of phenytoin and rifampin by piperine and decreased bioavailability of indinavir, tacrolimus, cyclosporine, digoxin, and fexofenadine by coadministered St. John's wort. However, many of these drugs are also substrates of CYP3A4. Thus, the modulation of intestinal Pgp and CYP3A4 represents an important mechanism for many clinically important herb-drug interactions. Further studies are needed to explore the relative role of Pgp and CYP3A4 modulation by herbs and the mechanism for the interplay of these two important proteins in herb-drug interactions.

Structure elucidation and antioxidant activity of (-)-isosilandrin isolated from Silybum marianum L

A regioisomer of the known flavanolignan (-)-silandrin (3a), named (-)-isosilandrin (8a), was isolated from the fruits of a white-flowered variant of Silybum marianum L. populated in Hungary. Its structure was established both by spectroscopic methods and total synthesis, and its absolute configuration was determined by means of circular dichroism. This compound showed stronger inhibitory activity on the superoxide anion (O2*-) release by human polymorphonuclear leukocytes (PMNL) than (+)-silybin (1a,b).

Protection against lipopolysaccharide-induced sepsis and inhibition of interleukin-1β and prostaglandin E2 synthesis by silymarin

Silymarin is known to have hepatoprotective and anticarcinogenic effects. Recently, anti-inflammatory effect of silymarin is attracting an increasing attention, but the mechanism of this effect is not fully understood. Here, we report that silymarin protected mice against lipopolysaccharide (LPS)-induced sepsis. In this model of sepsis, silymarin improved the rate of survival of LPS-treated mice from 6 to 38%. To further investigate the mechanism responsible for anti-septic effect of silymarin, we examined the inhibitory effect of silymarin on interleukin-1beta (IL-1beta) and prostaglandin E2 (PGE2) production in macrophages. Silymarin dose-dependently suppressed the LPS-induced production of IL-1beta and PGE2 in isolated mouse peritoneal macrophages and RAW 264.7 cells. Consistent with these results, the mRNA expression of IL-1beta and cyclooxygenase-2 was also completely blocked by silymarin in LPS-stimulated RAW 264.7 cells. Moreover, the LPS-induced DNA binding activity of nuclear factor-kappaB/Rel was also inhibited by silymarin in RAW 264.7 cells. Taken together, these results demonstrate that silymarin has a protective effect against endotoxin-induced sepsis, and suggest that this is mediated, at least in part, by the inhibitory effect of silymarin on the production of IL-1beta and PGE2.