Inhibition of cyclooxygenase-2 and inducible nitric oxide synthase by silymarin in proliferating mesenchymal stem cells: comparison with glutathione modifiers

Rosuvastatin attenuates total-tau serum levels and increases expression of miR-124-3p in dyslipidemic Alzheimer's patients: a historic cohort study

microRNAs are candidate diagnostic biomarkers for Alzheimer's disease. This study aimed to compare Silymarin with Rosuvastatin and placebo on total-Tau protein level and expression levels of microRNAs and TGF-β and COX-2 in Alzheimer's patients with secondary dyslipidemia. 36 mild AD patients with dyslipidemia were divided into three groups of 12. The first group received silymarin (140mg), the second group received placebo (140mg), and the third group recieved Rosuvastatin (10mg). Tablets were administered three times a day for Six months. The blood samples of the patients were collected before and after the intervention and the serum was separated. Using the RT-qPCR method, the expression levels of miR-124-3p and miR-125b-5p were assessed, and the serum levels of total-Tau, TGF-β, and COX-2 enzyme were measured using the ELISA method. Data were analyzed with SPSS software. In this study, the level of Δtotal-Tau was significantly lower in the Rosuvastatin group compared to the placebo (P = 0.038). Also, a significant reduction in the level of ΔTGF-β was observed in the Silymarin to Rosuvastatin group (p = 0.046) and ΔmiR-124-3p was significantly increased in the Rosuvastatin compared to the placebo group (p = 0.044). Rosuvastatin outperformed silymarin in decreasing Δtotal-Tau serum levels and enhancing expression of ΔmiR-124-3p, attributed to Rosuvastatin's capacity to lower cholesterol levels and inflammation concurrently. Conversely, silymarin was more effective than Rosuvastatin in reducing levels of ΔTGF-β. Serum miR-124-3p could serve as a promising diagnostic biomarker and a new therapeutic focus in AD.

Synthesis, characterization and hepatoprotective effect of silymarin phytosome nanoparticles on ethanol-induced hepatotoxicity in rats

Introduction

Silymarin proved to be a beneficial herbal medicine against many hepatic disorders such as alcoholic liver disease (ALD). However, its application is restricted due to its low bioavailability and consequently decreased efficacy. We herein used a nano-based approach known as "phytosome", to improve silymarin bioavailability and increase its efficacy.

Methods

Phytosome nanoparticles (NPs) were synthesized using thin film hydration method. NPs size, electrical charge, morphology, stability, molecular interaction, entrapment efficiency (EE %) and loading capacity (LC %) were determined. Moreover, in vitro toxicity of NPs was investigated on mesenchymal stem cells (MSCs) viability using MTT assay. In vivo experiments were performed using 24 adult rats that were divided into four groups including control, ethanol (EtOH) treatment, silymarin/EtOH treatment and silymarin phytosome/EtOH, with 6 mice in each group. Experimental groups were given 40% EtOH, silymarin (50 mg/kg) and silymarin phytosome (200 mg/kg) through the gastric gavage once a day for 3 weeks. Biochemical parameters, containing ALP, ALT, AST, GGT, GPx and MDA were measured before and after experiment to investigate the protective effect of silymarin and its phytosomal form. And histopathological examination was done to evaluate pathological changes.

Results

Silymarin phytosome NPs with the mean size of 100 nm were produced and were well tolerated in cell culture. These NPs showed a considerable protective effect against ALD through inverting the biochemical parameters (ALP, ALT, AST, GGT, GPx) and histopathological alterations.

Conclusion

Silymarin phytosomal NPs can be used as an efficient treatment for ALD.

Effects of silymarin and mesenchymal stem cells on hematological and some biochemical changes induced by gamma radiation in albino rats

Purpose: The present study was undertaken to evaluate the protective and therapeutic effects of silymarin and mesenchymal stem cells (MSCs) to ameliorate the damage caused by gamma radiation.Materials and methods: MSCs were given by intravenous injection to male rats (1.4 × 10⁷ cells), 1 day next to gamma radiation (4Gy). While, silymarin was administered orally at a dose of 70 mg/kg b. wt., 3 days before irradiation and continued for 21 days post irradiation.Results: After 1 and 3 weeks post-irradiation, the results revealed a significant decline in red blood corpuscles (RBCs), white blood corpuscles (WBCs) and platelets count with rising in serum lipid profile [total lipids (TL), total glycerides (TG), total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C) and very low density lipoprotein-cholesterol (VLDL-C) levels] and total bilirubin; while significant decreases in serum total protein and high density lipoprotein-cholesterol (HDL-C) levels were observed. In irradiated animals receiving double treatment with MSCs and silymarin; amelioration of the changes observed in hematological and biochemical parameters when comparing with the irradiated group.Conclusions: Treatment with a radio-protector (such as silymarin) in addition to MSCs transplantation was recommended to protect against gamma radiation injury.

Natural Compounds as a Strategy to Optimize "In Vitro" Expansion of Stem Cells

The efficient use of stem cells for transplantation is often limited by the relatively low number of stem cells collected. The ex vivo expansion of human stem cells for clinical use is a potentially valuable approach to increase stem cell number. Currently, most of the procedures used to expand stem cells are carried out using a 21% oxygen concentration, which is about 4- to 10-fold greater than the concentration characteristic of their natural niches. Hyperoxia might cause oxidative stress with a deleterious effect on the physiology of cultured stem cells. In this review, we investigate and critically examine the available information on the ability of natural compounds to counteract hyperoxia-induced damage in different types of stem cells ex vivo. In particular, we focused on proliferation and stemness maintenance in an attempt to draw up useful indications to define new culture media with a promoting activity on cell expansion in vitro.

Modulatory effect of silymarin on inflammatory mediators in experimentally induced benign prostatic hyperplasia: emphasis on PTEN, HIF-1α, and NF-κB

The current study aimed to investigate the potential role of the anti-inflammatory effects of silymarin (SIL) in inhibiting experimentally induced benign prostatic hyperplasia (BPH) in rats. Rats were injected testosterone (3 mg/kg/day, subcutaneously (s.c.)) for 2 weeks. In the treatment group, SIL (50 mg/kg, per orally (p.o.)) was administered daily to rats concomitantly with testosterone. Rats were killed 72 h after the last testosterone injection. Then, prostate tissues were dissected out, weighed, and subjected to histological, immunohistochemical, and biochemical examinations. Rats treated with testosterone showed marked increase in prostate weight and prostate weight/body weight with histopathological picture of inflammation and hyperplasia as well as increased collagen deposition. Co-treatment with SIL significantly alleviated these pathological changes. Further, SIL attenuated testosterone-induced nuclear factor-kappa B (NF-κB), cyclooxygenase-II (COX-II), and inducible nitric oxide synthase (iNOS) upregulation, and blunted testosterone-mediated increase in nitric oxide level and messenger RNA (mRNA) expression of interleukin-6 (IL-6) and IL-8. Testosterone-induced downregulation of phosphatase and tensin homolog (PTEN) and upregulation of hypoxia-inducible factor 1α (HIF-1α) were alleviated by SIL. Our findings highlight the anti-inflammatory properties of SIL as a crucial mechanism of its preventive actions against experimental BPH. This can be attributed to, at least partly, attenuating the expression of NF-kB and the subsequent inflammatory cascade, ameliorating the expression of PTEN, and mitigating that of HIF-1α. These data warrant further investigations for the potential use of SIL in the management of BPH.

Nitrosative stress and nitrated proteins in trichloroethene-mediated autoimmunity

Exposure to trichloroethene (TCE), a ubiquitous environmental contaminant, has been linked to a variety of autoimmune diseases (ADs) including SLE, scleroderma and hepatitis. Mechanisms involved in the pathogenesis of ADs are largely unknown. Earlier studies from our laboratory in MRL+/+ mice suggested the contribution of oxidative/nitrosative stress in TCE-induced autoimmunity, and N-acetylcysteine (NAC) supplementation provided protection by attenuating oxidative stress. This study was undertaken to further evaluate the contribution of nitrosative stress in TCE-mediated autoimmunity and to identify proteins susceptible to nitrosative stress. Groups of female MRL +/+ mice were given TCE, NAC or TCE + NAC for 6 weeks (TCE, 10 mmol/kg, i.p., every 4^th day; NAC, ∼250 mg/kg/day via drinking water). TCE exposure led to significant increases in serum anti-nuclear and anti-histone antibodies together with significant induction of iNOS and increased formation of nitrotyrosine (NT) in sera and livers. Proteomic analysis identified 14 additional nitrated proteins in the livers of TCE-treated mice. Furthermore, TCE exposure led to decreased GSH levels and increased activation of NF-κB. Remarkably, NAC supplementation not only ameliorated TCE-induced nitrosative stress as evident from decreased iNOS, NT, nitrated proteins, NF-κB p65 activation and increased GSH levels, but also the markers of autoimmunity, as evident from decreased levels of autoantibodies in the sera. These findings provide support to the role of nitrosative stress in TCE-mediated autoimmune response and identify specific nitrated proteins which could have autoimmune potential. Attenuation of TCE-induced autoimmunity in mice by NAC provides an approach for designing therapeutic strategies.

Treated effect of silymarin on vascular function of aged rats: Dependant on nitric oxide pathway

Abstract Context: Aging leads to endothelial dysfunction and vascular stiffness which are the main causes of many cardiovascular diseases. Previous reports have shown that the cell protective effect of silymarin (SM) is dependent on its antioxidant properties. Objectives: We investigated the effect of SM on vascular functions of aged rats and the involvement of nitric oxide or cyclooxygenase (COX) activity in this effect. Materials and methods: Isolated rat aortas were obtained from 22-month old rats. Each ring was incubated with SM (50 mg/L), SM/l-nitro-arginine methyl ester (100 μM, l-NAME) or SM/indomethacin (10 μM, INDO) in tissue bath. Three- to four-month-old rats were used as young controls. Endothelium-intact rings were precontracted with α-receptor agonist phenylephrine (0.001-30 µM) or voltage-dependent high potassium (40 mM), endothelium dependent/independent relaxant responses were obtained using acetylcholine (0.001-30 µM) and sodium nitroprusside (0.0001-3 µM), respectively. Results: Aging increased phenylephrine sensitivity (6.45 ± 0.08; 6.88 ± 0.09) and decreased KCl contraction (882 ± 118.4; 499 ± 80.4). SM treatment decreased the Emax of both agents (548 ± 109; 223 ± 48.9). Aging deteriorated acetylcholine relaxation (93.9 ± 2.09; 72.0 ± 2.56) and SM improved the response (86.3 ± 1.90). l-NAME prevented the SM effect whereas INDO was ineffective. Discussion and Conclusion: Immediate SM treatment partially restored endothelial dysfunction and vascular tone in aging. The possible mechanism might not be mediated by prostacyclin or the COX pathway in acute administration; the nitric oxide pathway and calcium antagonistic features of SM relate to its action on the vessel.

Potential roles of metallothioneins I and II in protecting bone growth following acute methotrexate chemotherapy

Metallothioneins (MTs) are known to participate in protection against oxidative stress. This study assessed the effects of MT-I&II gene knockout on methotrexate (MTX)-induced bone damage in growing mice. MT-I&II knockout (MT⁻/⁻) and wild type (MT⁺/⁺) male mice were injected with saline or 12.5 mg kg⁻¹ MTX for three consecutive days. MTX treatment was shown to cause more severe damage in MT⁻/⁻ mice when compared to MT⁺/⁺ mice, as demonstrated by the more obvious thinning of growth plate, reduced proliferation and increased apoptosis of chondrocytes, and reduced metaphysis heights in the knockout mice. Analysis of total liver glutathione (the most abundant intracellular antioxidant) also revealed significant lower glutathione levels in all MT⁻/⁻ mice. In conclusion, MT⁻/⁻ mice were more susceptible than MT⁺/⁺ mice to MTX-induced bone damages, which may be associated with the reduction of basal antioxidant defence, suggesting a protective role of MTs in the growing skeleton against damages caused by MTX chemotherapy.

Silymarin improves vascular function of aged ovariectomized rats

Both aging and estrogen depletion lead to endothelial dysfunction, which is the main reason of many cardiovascular diseases. Previous reports have shown that cell protective effect of silymarin (SM) depends on its antioxidant and phytoestrogenic properties. We investigated the effect of SM on vascular stiffness of aged menopausal rats and the involvement of estrogenic activity in this effect. Isolated rat aortas were obtained from 22-month-old rats, after 18 months of ovariectomy (OVX) follow-up. Each ring was incubated in tissue bath either with SM (50 mg/L) and 17β-estradiol (10 μM, E2) or in the presence of SM/fulvestrant (50 mg/L, 10 μM). Endothelium-intact rings were precontracted with phenylephrine (0.001-30 μM) or high potassium (40 mM); endothelium-dependent/independent relaxant responses were obtained using acetylcholine (0.001-30 μM) and sodium nitroprusside (0.0001-3 μM), respectively. While phenylephrine sensitivity was significantly increased in OVX rats, relaxations were significantly less in aged OVX rats compared with young rats. In spite of the presence of estrogen antagonist, immediate SM treatment restored the endothelial function and vascular tone better than estrogen replacement. Additionally, as a complementary and alternative medicine, it does not cause estrogenic side effects when taken acutely.