Sulphated polysaccharides: new insight in the prevention of cyclosporine A-induced glomerular injury

Natural Reno-Protective Agents against Cyclosporine A-Induced Nephrotoxicity: An Overview

CA (cyclosporine A) is a powerful immunosuppressing agent that is commonly utilized for treating various autoimmune illnesses and in transplantation surgery. However, its usage has been significantly restricted because of its unwanted effects, including nephrotoxicity. The pathophysiology of CA-induced kidney injury involves inflammation, apoptosis, tubular injury, oxidative stress, and vascular injury. Despite the fact that exact mechanism accountable for CA's effects is inadequately understood, ROS (reactive oxygen species) involvement has been widely proposed. At present, there are no efficient methods or drugs for treating CA-caused kidney damage. It is noteworthy that diverse natural products have been investigated both in vivo and in-vitro for their possible preventive potential in CA-produced nephrotoxicity. Various extracts and natural metabolites have been found to possess a remarkable potential for restoring CA-produced renal damage and oxidative stress alterations via their anti-apoptosis, anti-inflammatory, and antioxidative potentials. The present article reviews the reported studies that assess the protective capacity of natural products, as well as dietary regimens, in relation to CA-induced nephrotoxicity. Thus, the present study presents novel ideas for designing and developing more efficient prophylactic or remedial strategies versus CA passive influences.

Sulphated polysaccharide from Sargassum myriocystum confers protection against gentamicin-induced nephrotoxicity in adult zebrafish

The beneficial effect of purified fraction of sulphated polysaccharide extracted from Sargassum myriocystum (SMP) was examined on the gentamicin-induced nephrotoxicity in adult zebrafish. The major purified fractions (SMP1, SMP2 and SMP3) were obtained by anion-exchange and size-exclusion chromatography and characterized by FTIR, GCMS and NMR. The in vitro antioxidant activities of all purified SMP fractions were analysed. The SMP2 showed maximum carbohydrate, sulphate and fucose content with strong antioxidant activity than other fractions. Further, we evaluated the efficacy of SMP2 against gentamicin-induced nephrotoxicity in zebrafish model. The SMP2 administered group showed a significant attenuation in oxidative stress and histopathological alterations observed in renal tissues of gentamicin treated group. Moreover, the SMP2 supressed renal mRNA expression levels of KIM-1, NF-κB, TNF-α and IL-6 in dose-dependent manner. Thus, the present study suggests that the SMP2 is a potent antioxidant with anti-inflammatory and renoprotective properties that ameliorated the GEN induced nephrotoxicity in adult zebrafish.

Hepatoprotective effect of fucoidan isolated from the seaweed Turbinaria decurrens in ethanol intoxicated rats

Fucoidan is the sulfated polysaccharide which is present in the cell wall of the brown seaweeds with high nutritive value. It is widely known for its pharmacological activity and hence it is added as a main ingredient in the food supplements. A water soluble crude polysaccharide was extracted from Turbinaria decurrens. Ethanol has been used as a hepatotoxin in vivo and its administration increased oxidative stress, decreased antioxidant defence and liver injury. Fucoidan treatment increased the body weight, food intake and serum protein levels, it decreases the level of hepatic markers. Fucoidan improved the antioxidant status of alcoholic rats, which is evaluated by the decreased levels of lipid peroxidation markers and increased level of enzymatic antioxidants were observed in liver. Histopathological observations and protein expression were also in correlation with the biochemical parameters. The hepatoprotective effect of fucoidan is probably due to its antioxidant effect.

Antioxidant and antiproliferative activities of heterofucans from the seaweed Sargassum filipendula

Fucan is a term used to denominate a type of polysaccharide which contains substantial percentages of l-fucose and sulfate ester groups. We obtained five heterofucans from Sargassum filipendula by proteolytic digestion followed by sequential acetone precipitation. These heterofucans are composed mainly of fucose, glucose, glucuronic acid, galactose and sulfate. These fucans did not show anticoagulant activity in PT and aPTT tests. Their antioxidant activity was evaluated using the follow tests; total antioxidant capacity, scavenging hydroxyl and superoxide radicals, reducing power and ferrous ion [Fe(II)] chelating. All heterofucans displayed considerable activity, especially SF-1.0v which showed the most significant antioxidant potential with 90.7 ascorbic acid equivalents in a total antioxidant capacity test and similar activity when compared with vitamin C in a reducing power assay. The fucan antiproliferative activity was performed with HeLa, PC3 and HepG2 cells using MTT test. In all tested conditions the heterofucans exhibited a dose-dependent effect. The strongest inhibition was observed in HeLa cells, where SF-1.0 and SF-1.5 exhibited considerable activity with an IC50 value of 15.69 and 13.83 μM, respectively. These results clearly indicate the beneficial effect of S. filipendula polysaccharides as antiproliferative and antioxidant. Further purification steps and additional studies on structural features as well as in vivo experiments are needed to test the viability of their use as therapeutic agents.

Evaluation of the marine alga Ulva rigida as a food supplement: effect of intake on intestinal, hepatic, and renal enzyme activities in rats

The use of seaweeds as a food is more widespread in Eastern than in Western countries, although demand for these plants has increased in the West because their possible usefulness as dietary supplements. However, very little is known about the effects of regular consumption of algae. The aim of the present study was to determine the composition of Ulva rigida and to evaluate the effects of dietary supplementation of the diet with 10% alga for 4 weeks on dietary intake, growth, protein efficiency ratio, diet conversion ratio, and some organ weights in growing male rats. We also studied the effect of inclusion of the alga in the diet on intestinal, hepatic, and renal enzymatic activities. U. rigida was found to be a good source of protein and carbohydrates. Food intake was higher in the U. rigida group than in the control group, but ingestion of alga did not have any effect on the other trophic parameters. The intestinal disaccharidase and leucine aminopeptidase activities were lower in rats fed with alga than in control rats, but γ-glutamyl transpeptidase activity was higher in the kidneys of alga-fed rats than in control rats. U. rigida contains high amounts of protein, carbohydrates, vitamins, and minerals and low amounts of lipids. Analysis of the amino acid composition revealed good-quality protein. The addition of alga to the diet inhibited disaccharidase activities, which suggested that alga consumption could be useful in some chronic disorders associated with pertubations of glucose homeostasis caused by carbohydrate absorption.

In vitro cancer chemopreventive properties of polysaccharide extract from the brown alga, Sargassum latifolium

Polysaccharides of edible algae attracted extensive interest due to their numerous biological activities. Sargassum latifolium (Turner) C. Agardh, belongs to Sargassaceae, is a brown algae in red sea shores in Egypt. This work is a novel attempt to explore the cancer chemopreventive activity of different fractions of water-soluble polysaccharide extract derived from S. latifolium. Estimation of cancer chemopreventive activity, specifically anti-initiation, including the modulation of carcinogen metabolism and the antioxidant capacity, revealed that E1 and E4 were potent anti-initiators, where they lead not only to an inhibition in the carcinogen activator cytochrome P450 1A (IC50 2.54 and 10.30 microg/ml, respectively), but also to an induction in the carcinogen detoxification enzymes glutathione-S-transferases (144% and 225% of the control, respectively). E1 and E4 inhibited 59% and 63% of the induced-DNA damage, as measured by comet assay. Similarly both E1 and E4 possessed potential anti-promoting properties as indicated by their anti-inflammatory activity. E1 and E4 enhanced the macrophage proliferation; however they dramatically inhibited the stimulated NO (30.7% and 59.3%), TNF-alpha (38.2% and 54.9) and COX-2 (20% and 18%), respectively. E3 showed a selective cytotoxicity against lymphoblastic leukemia (1301 cells), while other fraction extracts had no cytotoxic effect against all tested cell lines. E3 led to a major disturbance in cell cycle including arrest in both S-phases in 1301 cells. This disturbance was associated with an induced-cell death due to apoptosis, but not necrosis. In conclusion, E1 and E4 are promising cancer chemopreventive fractions, since they had tumor anti- initiating activity via their protective modulation of carcinogen metabolism, and tumor anti-promoting activity via their anti-inflammatory activity, while E3 can be considered as a promising anti-cancer agent against leukemia.

Beneficial effects of sulfated polysaccharides from Sargassum wightii against mitochondrial alterations induced by Cyclosporine A in rat kidney

Sulfated polysaccharides from marine seaweeds are receiving continuous attention owing to their wide therapeutic applications and are known to inhibit free radical generation. It has been well known that mitochondria are the major sources as well as the target of free radicals. The renal tubules have high density of mitochondria and therefore show structural and functional defects in acute renal failure. Hence, the present study is designed to appraise the mitochondrial status during Cyclosporine A (CsA)-induced nephrotoxicity and the effect of sulfated polysaccharides over it. Sulfated polysaccharides (5 mg/kg body weight, subcutaneously) treatment significantly prevented the CsA-induced (25 mg/kg body weight, orally) mitochondrial damage. CsA-induced mitochondrial oxidative stress in rat kidney was evident from increased reactive oxygen species level, decreased antioxidant defense system, coupled with enhanced lipid peroxidation. Further, the activities of tricarboxylic acid cycle and electron transport chain enzymes were decreased in CsA-induced rats, along with a significant increase in the activities of urinary enzymes, thus indicating renal tubular injury. Ultrastructural changes were also in accord with the above aberrations. The above abnormalities were favorably modulated by sulfated polysaccharides supplementation, thus highlighting the significance of sulfated polysaccharides in preventing the renal mitochondrial dysfunction allied with CsA-provoked nephrotoxicity.