Nahla N. Younis

Silymarin-loaded Eudragit(®) RS100 nanoparticles improved the ability of silymarin to resolve hepatic fibrosis in bile duct ligated rats.

UNLABELLED Some nano-formulations of silymarin (SM), a drug commonly used for liver diseases, were developed to overcome its poor solubility and poor bioavailability; antifibrotic effect of these formulations has not been tested yet. In this study we aimed to formulate and evaluate silymarin-loaded Eudragit(®) RS100 nanoparticles (SMnps) and to test the capability of SMnps to reverse an established fibrosis model. SMnps were prepared by solvent evaporation and nano-precipitation techniques. The influence of drug:polymer ratio, concentration of surfactant in the aqueous phase on particle size, drug entrapment efficiency (EE) % and in vitro drug releases were investigated. For in vivo evaluation, bile duct ligated (BDL)-rats were treated with either SM or SMnps every other day (125mg/kg) orally for 3 weeks started 3 weeks after BDL. Liver function tests, oxidative stress and fibrosis/fibrogenesis process were evaluated using biochemical and histopathological techniques. The formulation No (F4) of SMnps showed an average particle size of 632.28±12.15nm, a drug EE% of 89.47±1.65% and released the drug in a prolonged manner over 24h. The prepared SMnps were nearly spherical with smooth surfaces. In BDL-rats, treatments with either SM or SMnps corrected liver function and oxidative stress. Only SMnps was able to reverse the induced fibrosis; SMnps significantly decreased serum tumor necrosis factor- α (TNF-α), serum transforming growth factor- β1 (TGF-β1), hepatic hydroxyproline and downregulated the hepatic expression of tissue inhibitor metalloproteinase-1 (TIMP-1) and cytokeratin-19 (CK-19), whilst increased hepatic hepatocytes growth factor (HGF) and upregulated the hepatic expression of matrix metalloproteinase-2 (MMP-2) and increased MMP-2/TIMP-1 ratio at mRNA level. Livers of rats treated with SMnps showed very little collagen in ECM and restored hepatic architecture as compared to either BDL rats or rats treated with SM. CONCLUSION Formulation of silymarin as nanoparticles improved its ability to resolve cholestasis-induced liver fibrosis by restoring hepatic regenerative capabilities. Therefore, formulation of SMnps may represent a step forward in the field of anti-fibrotic drug development.

Pyridoxamine, an inhibitor of protein glycation, in relation to microalbuminuria and proinflammatory cytokines in experimental diabetic nephropathy

Diabetic nephropathy (DN) is one of the major complications that develop as consequence of chronic and uncontrolled hyperglycaemia. Hyperglycaemia initiates various processes, one of which is protein glycation, leading to the formation of advanced glycation end products. Alteration of intracellular signalling, gene expression, release of proinflammatory molecules and free radicals are examples of such changes and they contribute to the initiation of diabetic complications. In the current manuscript, we studied the effect of pyridoxamine (PM) on protein glycation, oxidative stress, interleukin-1α (IL-1α), IL-6, C-reactive protein (CRP), gene expression of tumour necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1) in relation to microalbuminuria and kidney functions in a model of alloxan-induced diabetic rats. We have observed that onset of microalbuminuria has preceded the gradual increase of blood sugar level in diabetic rats. In diabetic rats, gene expression of TNF-α and TGF-β1 recorded a gradual increase and marked increase was observed after one and two weeks of alloxan administration, in comparison with normal rats. PM induced significant decrease in kidney malondialdehyde content and the gene expression of TNF-α and TGF-β1, in addition to levels of serum glucose, fructosamine, urea, creatinine, IL-1α, IL-6, CRP and urine microalbumin. Histopathological examination of kidney tissues showed certain improvements as compared with diabetic control. In conclusion, our results may provide a supporting evidence for the therapeutic benefit of PM in DN.

10-Dehydrogingerdione raises HDL-cholesterol through a CETP inhibition and wards off oxidation and inflammation in dyslipidemic rabbits

OBJECTIVE To investigate the CETP suppression by 10-dehydrogingerdione, a compound in Zingiber officinale, and its effect on the progression of atherosclerosis in dyslipidemic rabbits and the underlying oxidative and inflammatory consequences. METHODS Twenty-four New Zealand male rabbits were fed either a normal diet or an atherogenic diet. The rabbits on the atherogenic diet received treatments of atorvastatin or 10-dehydrogingerdione and placebo concurrently (n = 6/group). Blood samples were collected after three and six weeks for biochemical analysis. RESULTS 10-Dehydrogingerdione-treated rabbits showed a significant improvement in serum lipids especially HDL-C in a time-dependant manner. This effect was correlated to its ability to lower CETP. Lp(a), ox-LDL, hsCRP, homocysteine and MMP9 decreased significantly in both 10-dehydrogingerdione- and atorvastatin-treated rabbits compared with placebo (p < 0.001). Lp(a) achieved normal values by both treatments, while homocysteine did not reach normal values by either treatments. Conversely, MMP9 returned below normal values by 10-dehydrogingerdione (p < 0.001), hsCRP and ox-LDL were slightly below normal values (hsCRP: p < 0.001; ox-LDL: p < 0.001 and p < 0.05 in 10-dehydrogingerdione and atorvastatin groups, respectively). The effect achieved by 10-dehydrogingerdione was similar to that of atorvastatin on hsCRP and Lp(a). However, 10-dehydrogingerdione exerted better effect than atorvastatin on homocysteine, MMP9 (p < 0.001) and ox-LDL (p < 0.05). CONCLUSIONS In a rabbit dyslipidemic model, 10-dehydrogingerdione lowers LDL-C and raises HDL-C by suppressing CETP; an effect that modulates inflammatory and oxidative risk factors of CVD. These findings suggested that the naturally occurring 10-dehydrogingerdione might be a potential CETP inhibitor for the treatment of atherosclerosis and residual risk in CVD.

Bone marrow-derived mesenchymal stem cells effectively regenerate fibrotic liver in bile duct ligation rat model

Mesenchymal stem cells (MSCs) have attracted lots of attention for the treatment of acute liver failure and end-stage liver diseases. This study aimed at investigating the fundamental mechanism by which bone marrow-derived MSCs (BM-MSCs) induce liver regeneration of fibrotic liver in rats. Rats underwent bile duct ligation (BDL) surgery and four weeks later they were treated with either BM-MSCs (3 × 106 cells /rat, once, tail vein injection) or silymarin (100 mg/kg, daily, orally) for four weeks. Liver function tests and hepatic oxidative stress were determined. Hepatic injury and fibrosis were assessed by H and E, Sirus red staining and immunohistochemical expression of α-smooth muscle actin (α-SMA). Hepatocyte growth factor (HGF) and the gene expression of cytokeratin-19 (CK-19) and matrix metalloproteinase-2 (MMP-2) in liver tissue were determined. BDL induced cholestatic liver injury characterized by elevated ALT and AST activities, bilirubin and decreased albumin. The architecture damage was staged as Metavir score: F3, A3. Fibrosis increased around proliferating bile duct as indicated by sirus red staining and α-SMA immunostaining. Fibrogenesis was favored over fibrolysis and confirmed by decreased HGF with increased expression of CK-19, but decreased MMP-2 expression. BM-MSCs treatment restored deteriorated liver functions and restored the histological changes, resolved fibrosis by improving liver regenerative capabilities (P < 0.001), increases in HGF and MMP-2 mRNA and downregulating CK-19 mRNA. Sliymarin, however, induced similar but less prominent effects compared to BM-MSCs. In conclusion, liver regenerative capabilities can be stimulated by BM-MSCs via augmentation of HGF that subsequently up-regulate MMP-2 mRNA while downregulating CK-19 mRNA.

Atheroprotective potentials of curcuminoids against ginger extract in hypercholesterolaemic rabbits

The anti-atherogenic potentials of total ginger (Zingiber officinale) extract (TGE) or curcuminoids extracted from turmeric (Curcuma longa), members of family Zingiberaceae, were compared in hypercholesterolaemia. Rabbits were fed either normal or atherogenic diet. The rabbits on atherogenic diet received treatments with TGE or curcumenoids and placebo concurrently for 6 weeks (n = 6). The anti-atherogenic effects of curcuminoids and ginger are mediated via multiple mechanisms. This effect was correlated with their ability to lower cholesteryl ester transfer protein activity. Ginger extract exerted preferential effects on plasma lipids, reverse cholesterol transport, cholesterol synthesis and inflammatory status. Curcuminoids, however, showed superior antioxidant activity.

The synergistic effect between vanillin and doxorubicin in ehrlich ascites carcinoma solid tumor and MCF-7 human breast cancer cell line.

Despite the remarkable anti-tumor activity of doxorubicin (DOX), its clinical application is limited due to multiple organ toxicities. Products with less side effects are therefore highly requested. The current study investigated the anti-cancer activities of vanillin against breast cancer and possible synergistic potentiation of DOX chemotherapeutic effects by vanillin. Vanillin (100mg/kg), DOX (2mg/kg) and their combination were administered i.p. to solid Ehrlich tumor-bearing mice for 21days. MCF-7 human breast cancer cell line was treated with vanillin (1 and 2mM), DOX (100μM) or their combination. Protection against DOX-induced nephrotoxicity was studied in rats that received vanillin (100mg/kg, ip) for 10days with a single dose of DOX (15mg/kg) on day 6. Vanillin exerted anticancer effects comparable to DOX and synergesticlly potentiated DOX anticancer effects both in-vivo and in-vitro. The anticancer potency of vanillin in-vivo was mediated via apoptosis and antioxidant capacity. It also offered an in-vitro growth inhibitory effect and cytotoxicity mediated by apoptosis (increased caspase-9 and Bax:Bcl-2 ratio) along with anti-metasasis effect. Vanillin protected against DOX-induced nephrotoxicity in rats. In conclusion, vanillin can be a potential lead molecule for the development of non-toxic agents for the treatment of breast cancer either alone or combined with DOX.

10-DHGD ameliorates cisplatin-induced nephrotoxicity in rats.

Organs subjected to chronic injuries may develop tissue fibrosis. Several factors contribute to the combat injurious stimuli to repair, heal and alleviate any disturbance. Secretion of chemokines, migration of inflammatory cells to the affected site and activation of fibroblast for production of extracellular matrix (ECM) are examples. Recently, few studies have delt with 10-dehydrogingerdione (10-DHGD), one of the active constituent of ginger extracts that has been published. This constituent proved to be potent antioxidant, anti-inflammatory, cholesterol ester transfer protein (CETP) inhibitor, indeed, a hypolipemic agent. It has been selected in the present study as a natural anti-inflammatory agent to combat inflammation, nephrotoxicity and renal fibrosis-induced by cisplatin. Renal fibrosis state demonstrated a significant increase in creatinine, urea, nuclear factor kappa (NF-kB), insulin like growth factor I (IGF-I), fibroblast growth factor-23 (FGF-23) along with a significant decrease of hepatocytes growth factor (HGF), renal glutathione (GSH) and in confirm to histopathological examination of kidney tissue. Administration of 10-DHGD orally daily for 4 weeks resulted in a significant improvement of both the biomarkers studied in addition to the histopathological profile of the renal tissues. CONCLUSION 10-DHGD exhibited a marked anti-inflammatory potential, alleviated to a great extent of nephrotoxicity and renal fibrosis induced by cisplatin.

Modulation of brain insulin signaling in Alzheimer’s disease: New insight on the protective role of green coffee bean extract

Objective: Alzheimers disease (AD), a neurodegenerative disorder, involves brain insulin signaling cascades and insulin resistance (IR). Because of limited treatment options, new treatment strategies are mandatory. Green coffee bean extract (GCBE) was reported to attenuate IR and improve brain energy metabolism. We aimed to investigate the possible use of GCBE as a prophylactic strategy to delay the onset of AD or combined with pioglitazone (PIO) as a strategy to retard the progression of AD. Methods: Rats received 10% fructose in drinking water for 18 weeks to induce AD. GCBE-prophylactic group received GCBE for 22 weeks started 4 weeks prior to fructose administration. The PIO group treated with PIO for 6 weeks started on week 12 of fructose administration. The GCBE+PIO group received GCBE for 22 weeks started 4 weeks prior to fructose administration and treated with PIO for the last 6 weeks of fructose administration. Results: Pretreatment with GCBE, either alone or combined with PIO, alleviated IR-induced AD changes. GCBE improved cognition, decreased serine phosphorylation of insulin receptor substrate, increased phosphoinositol-3 kinase (PI3K) activity and protein kinase B (Akt) gene expression, decreased glycogen synthase kinase-3β (GS3Kβ) gene expression and Tau hyperphosphorylation. Discussion: GCBE exerted neuroprotective effects against IR-induced AD mediated by alleviating IR and modulating brain insulin signaling cascade.