COMPARATIVE ANALYSIS OF BIOLOGICAL ACTIVITY OF SILYBUM MARIANUM L. FOOD SUPPLEMENTS AVAILABLE ON MARKET: INVITRO STUDY

Objective: Silybum marianum L. Food Supplements that contain silymarin is widely used as a therapeutic agent in liver diseases. Many brands are available on the market in USA, Egypt, Europe and other countries. The objective of this study was to compare the biological activity in different preparations of silymarin available on the market in USA and Egypt using paracetamol-induced oxidative stress injury on primary cultured rat hepatocytes. Methods: Forty four silymarin samples available on the market were collected from USA (24) and Egypt (20) and tested for hepat protective antioxidant effects on primary cultured rat hepatocytes. Cytotoxicity was measured by MTT [3-(4, 5-dimethyl-thiazol-2)-2,5-diphenyl tetrazolium bromide] assay and lactate dehydrogenase (LD) leakage into culture medium. Antioxidant effects were determined by glutathione reductase (GR), and Nitric oxide (NO) assays in silymarin, pretreated rat hepatocytes for 2 h followed by incubation with 25 mM paracetamol over a period of 1 h. Therapeutic index was calculated for each tested sample for comparative analysis. Results: Silymarin preparations significantly decreased toxicity induced by paracetamol in rat hepatocytes, decreased lactate dehydrogenase leakage and prevented GSH depletion (P<0.01) and returned NO to basal levels in rat hepatocytes. The therapeutic index was 80, 40 and 20 for samples No. 20, 19 and 5 respectively. Conclusions: The 44 different silymarin preparations tested in this study exhibited variation in antioxidant capacity and in reducing nitric oxide produced as a result of paracetamol injury. This variation in biological activity did not always correspond to the amount of silymarin recorded on samples

Injury-induced alterations in newly synthesized sulphated proteoglycans from rabbit arterial neointima covered by regenerated endothelium

Proteoglycan (PG) synthesis is a highly regulated, dynamic process that is known to be altered during atherogenesis. Endothelial injury, which may be the primary event in atherosclerosis, has been reported to stimulate PG synthesis and accumulation in the arterial extracellular matrix. The objective of this investigation was to study injury-induced alterations in PG synthesis and accumulation in the neointima, developed in response to a selective balloon catheter de-endothelialization of aortas of normocholesterolaemic rabbits. One group of rabbit aortas was incubated with 35S-Na2SO4 for 8 h, to study in vitro the de novo synthesis of sulphated PG. Another group of rabbit aortas was used to study PG accumulated in aortic neointima vs. PG present in intima-media of normal aortas. Newly synthesized sulphated PG was characterized by light microscopic radioautography and size exclusion chromatography. Purified intimal-medial PG extracts from unlabelled aortas were analysed for protein and glycosaminoglycan (GAG) content and GAG distribution pattern. Results from this study revealed that the neointima of injured aortas synthesized sulphated PG at a significantly higher concentration than the intima of normal aortas. Size exclusion chromatography revealed that neointima synthesized higher molecular weight PG, and in a higher proportion, than its counterpart PG from normal aortas. PG accumulated in neointima of injured aortas showed a significantly altered GAG distribution pattern. These data confirm that neointima developed in response to injury synthesizes and accumulates PG which is altered compared to PG present in the intima-media of normal aorta

The Role of Monocyte/Macrophage and CXCR3 in Differentiation between Recurrent Hepatitis C and Acute Cellular Rejection Postliver Transplantation

Objective. Liver transplantation (LT) is the recommended treatment for patients with advanced liver disease and cirrhosis in all guidelines, mostly as a complication of HCV. The distinction between reinfection of the graft with HCV and acute cellular rejection (ACR) is essential because they are managed differently. Hepatic macrophages, which can either arise from circulating blood-derived monocytes (BDM) or from resident tissue Kupffer cells, are central in the pathogenesis of chronic liver injury. The aim of this work was to evaluate whether the origin of macrophages and the immune mediator CXCR3 could help in differentiating between acute recurrent HCV and ACR after liver transplantation. Methods. Twenty-nine cases of recurrent hepatitis C and 26 cases of ACR were included in this study. The expression of CD 68 (macrophage marker), CD11b (BDM marker), and CxCR3 in the postliver transplant biopsy using immunohistochemistry was determined. Results. CD11b expression highlighting macrophages of BDM origin was in favor of recurrent hepatitis C (P<0.001) than in ACR (P=0.44), while CXCR3 expression by hepatocytes was in favor of ACR (P=0.001). Conclusion. Macrophage infiltrating liver tissue post LT can distinguish between ACR by upregulation of CXCR3 and recurrent hepatitis C by predominant CD11b