Protective effect of Spirulina on lead induced deleterious changes in the lipid peroxidation and endogenous antioxidants in rats

Preclinical antitoxic properties of Spirulina (Arthrospira)

CONTEXT

Spirulina (Arthrospira) exerts a wide spectrum of pharmacological activities which are mainly attributed to its antioxidant effect. However, Spirulina has also been reported (both in preclinical and in clinical scenarios) to exhibit other bioactive effects, including an antitoxic potential.

OBJECTIVE

We performed a systematic review of the literature, conducted in TOXNET, PubMed/MEDLINE, and Science Direct-Scopus; all available years were included. Searching criteria included the effects of Spirulina on experimental poisonings from arsenic, cadmium, carbon tetrachloride, deltamethrin, fluoride, hexachlorocyclohexane, iron, lead, lindane, and mercury.

RESULTS

In all cases, it was established that the blue-green alga, and its isolated compounds, effectively counteracted these pollutants toxic effects on the exposed organisms. Some molecular mechanisms are proposed, although they have not been fully elucidated yet.

CONCLUSION

Spirulina could be a useful coadjuvant agent within clinical practice for treatment of these or other pollutants poisonings.

The antioxidant, immunomodulatory, and anti-inflammatory activities of Spirulina: an overview

Spirulina is a species of filamentous cyanobacteria that has long been used as a food supplement. In particular, Spirulina platensis and Spirulina maxima are the most important. Thanks to a high protein and vitamin content, Spirulina is used as a nutraceutical food supplement, although its other potential health benefits have attracted much attention. Oxidative stress and dysfunctional immunity cause many diseases in humans, including atherosclerosis, cardiac hypertrophy, heart failure, and hypertension. Thus, the antioxidant, immunomodulatory, and anti-inflammatory activities of these microalgae may play an important role in human health. Here, we discuss the antioxidant, immunomodulatory, and anti-inflammatory activities of Spirulina in both animals and humans, along with the underlying mechanisms. In addition, its commercial and regulatory status in different countries is discussed as well. Spirulina activates cellular antioxidant enzymes, inhibits lipid peroxidation and DNA damage, scavenges free radicals, and increases the activity of superoxide dismutase and catalase. Notably, there appears to be a threshold level above which Spirulina will taper off the antioxidant activity. Clinical trials show that Spirulina prevents skeletal muscle damage under conditions of exercise-induced oxidative stress and can stimulate the production of antibodies and up- or downregulate the expression of cytokine-encoding genes to induce immunomodulatory and anti-inflammatory responses. The molecular mechanism(s) by which Spirulina induces these activities is unclear, but phycocyanin and β-carotene are important molecules. Moreover, Spirulina effectively regulates the ERK1/2, JNK, p38, and IκB pathways. This review provides new insight into the potential therapeutic applications of Spirulina and may provide new ideas for future studies.

Evaluating the ameliorative efficacy of Spirulina platensis on spermatogenesis and steroidogenesis in cadmium-intoxicated rats

The present study was conducted to evaluate the ameliorative efficacy of Spirulina platensis (SP) on reproductive dysfunctions induced by cadmium chloride (CdCl2) in male rats. Rats (n = 40) were divided into five groups (eight rats/each). Group 1: served as control without any treatment. Group 2: Rats were administered SP (150 mg/kg body weight (BW)) in drinking water for 10 days. Group 3: Rats were subcutaneously injected with CdCl2 (2 mg/kg BW) daily for 10 days. Group 4: Rats were co-treated with both CdCl2 (2 mg/kg BW) and SP (150 mg/kg BW) daily for 10 days (SP prophylactic group). Group 5: Rats received CdCl2 for 10 days followed by administration of SP alone in drinking water daily for another 30 days with the same mentioned routes and doses (SP treatment group). From our findings, the administration of SP alone or co-administration with Cd significantly attenuated the harmful effects of Cd, suggesting its beneficial role in improving spermatogenesis and steroidogenesis after Cd exposure.

Nephroprotective and antioxidant significance of selenium and α-tocopherol on lead acetate-induced toxicity of Nile Tilapia (Oreochromis niloticus)

The kidney plays an important physiological function, maintaining the osmoregulation and electrolyte balance of Nile tilapia (Oreochromis niloticus). Selenium and α-tocopherol (α-toc) are potent antioxidants, which improve the aquaculture health. In this study, we tested the potential ability of selenium and α-toc to alleviate the oxidative stress in the kidney induced by lead toxicity. Two hundred and twenty-five O. niloticus were divided into five groups. The control group received a basal diet. Lead nephrotoxicity was induced by daily application of 73.40 mg lead acetate/liter water for up to 10 weeks. Selenium and α-tocopherol were given 1 week before lead intoxication. Selenium was administered as sodium selenite, 4 mg/kg dry diet. Alpha-tocopherol acetate was administered as α-toc, 200 mg/kg dry diet. The last group received a mixture of selenium and α-toc in diet. Fish treated with selenium and/or α-toc (groups III-V) showed an amelioration of the adverse effects of lead toxicity and significant improvement in serum electrolytes (calcium, inorganic phosphate, and magnesium) and creatinine level compared with the positive control group (P ≤ 0.05). Treated groups showed significant decrease in superoxide dismutase (SOD) and reduced glutathione (GSH) activity with significant increase in malondialdehyde (MDA; P ≤ 0.05). It could be concluded that selenium and α-toc have a potential antioxidant effect and have the ability to improve the kidney function after lead intoxication of O. niloticus.

The Remedial Efficacy of Spirulina platensis versus Chromium-Induced Nephrotoxicity in Male Sprague-Dawley Rats

This study was conducted to investigate the possible protective effect of Spirulina platensis against chromium-induced nephrotoxicity. A total of 36 adult male Sprague-Dawley rats were divided into 4 equal groups (Gps). Gp1 served as control, rats of Gps 2, 3, and 4 were exposed to Spirulina platensis (300 mg/kg b.wt per os) and sodium dichromate dihydrate (SDD) via drinking water at concentration of 520 mg /l respectively. Chromium administration caused alterations in the renal function markers as evidenced by significant increase of blood urea and creatinine levels accompanied with significant increase in kidney’s chromium residues and MDA level as well as decreased catalase activity and glutathion content in kidney tissue. Histologically, Cr provoked deleterious changes including: vascular congestion, wide spread tubular epithelium necrobiotic changes, atrophy of glomerular tuft and proliferative hyperplasia. The latter was accompanied with positive PCNA expression in kidney tissues as well as DNA ploidy interpretation of major cellular population of degenerated cells, appearance of tetraploid cells, high proliferation index and high DNA index. Morphometrical measurements revealed marked glomerular and tubular lumen alterations. On contrary, spirulina co-treatment with Cr significantly restored the histopathological changes, antioxidants and renal function markers and all the previously mentioned changes as well.

Modulating Effects of Spirulina platensis against Tilmicosin-Induced Cardiotoxicity in Mice

Objective

Tilmicosin (TIL) is a long-acting macrolide antibiotic used to treat cattle for pathogens that cause bovine respiratory disease. However, overdoses of this medication have been reported to induce cardiac damage. Our experimental objective was to evaluate the protective effects of Spirulina platensis (SP) administration against TIL-induced cardiotoxicity in mice.

Materials and Methods

Our experimental in vivo animal study used 40 male albino mice that were divided into five groups of eight mice per group. The first group served as a control group and was injected with saline. The second group received SP at dose of 1000 mg/kg body weight for five days. The third group received a single dose of TIL (75 mg/kg, subcutaneously). Groups 4 and 5 were given SP at doses of 500 and 1000 mg/kg body weight for five consecutive days just before administration of TIL at the same dose and regimen used for group 3.

Results

TIL treated animals showed a significant increase in serum cardiac injury biomarkers as well as cardiac lipid peroxidation, however they had evidence of an inhibition in antioxidant biomarkers. SP normalized elevated serum levels of lactate dehydrogenase (LDH), creatine kinase (CK), and CK-MB. Furthermore, SP reduced TIL-induced lipid peroxidation and oxidative stress in a dose-dependent manner.

Conclusion

Administration of SP minimized the toxic effects of TIL by its free radicalscavenging and potent antioxidant activity.

Lead poisoning in Nile tilapia (Oreochromis niloticus): oxidant and antioxidant relationship

Selenium and vitamin E are very effective antioxidant agents which play important roles in improving and development of aquaculture sector. This study was conducted to determine the protective and treatment effects of vitamin E and selenium against lead toxicity. Administration of both vitamin E and selenium ameliorated the adverse effects of lead acetate toxicity through significant increase in hemoglobin, packed cell volume, RBC count, WBC count, and lymphocytes compared to lead acetate-exposed groups especially after the 10th week. Also, it is revealed that severe decrease of total protein, calcium, phosphorous, and magnesium in lead acetate intoxicated group. On contrary, significant increase of blood parameters upon addition of vitamin E and selenium combined with/without lead. On the other hand, insignificant decreases of sAST, sALT, urea, and creatinine in group fed on vitamin E and selenium, while increase in lead acetate intoxicated group. Lead acetate caused increasing of lipid peroxidation level (malondialdehyde) and decreasing of superoxide dismutase activity and reduced glutathione level. From these results, it is concluded that exposure to lead acetate is considered as hepatotoxic environmental pollutant. Exposure to lead acetate induced significant effects on antioxidant status. Antioxidants (vitamin E and selenium) showed important roles to protect body against lipid peroxidation, which considered as the first step of cell membrane damage, in addition to the improvement of the endogenous antioxidant enzyme activities.

Pharmacodynamic interaction of Spirulina platensis and deltamethrin in freshwater fish Nile tilapia, Oreochromis niloticus: impact on lipid peroxidation and oxidative stress

Spirulina platensis (SP) is one of the most commonly used dietary supplements in human and many animal species, including fish. Recently, it has gained more attention in fish not only for its growth-promoting and immunomodulatory effects but also for its antioxidant potential. The present study was conducted to investigate the protective role of two different dietary levels of SP on freshwater Nile tilapia; Oreochromis niloticus exposed to subacute deltamethrin (DLM) intoxication. Spirulina was supplemented at levels of 0.5 and 1 % in the diet along with DLM at a concentration of 1.46 μg/l for 28 days. Serum biochemical parameters, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total protein, albumin, cholesterol, urea, uric acid and creatinine, were estimated. In addition, the level of malondialdehyde (MDA) was analysed as a lipid peroxidation marker. Reduced glutathione (GSH) content and glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) activities were analysed as antioxidant biomarkers in liver, kidney and gills. The results revealed that DLM intoxication increased serum AST, ALT, ALP, cholesterol, urea, uric acid, creatinine and tissue MDA, while decreased serum total protein and albumin as well as tissue GSH level and GSH-Px, SOD and CAT activities. SP supplementation at the two tested levels enhanced all altered serum biochemical parameters as well as tissue lipid peroxidation and antioxidant biomarkers. Therefore, it could be concluded that SP administration could minimize DLM-induced toxic effects by its free radical scavenging and potent antioxidant activity.

Bioactive compounds from macroalgae in the new millennium: implications for neurodegenerative diseases

Marine environment has proven to be a rich source of structurally diverse and complex compounds exhibiting numerous interesting biological effects. Macroalgae are currently being explored as novel and sustainable sources of bioactive compounds for both pharmaceutical and nutraceutical applications. Given the increasing prevalence of different forms of dementia, researchers have been focusing their attention on the discovery and development of new compounds from macroalgae for potential application in neuroprotection. Neuroprotection involves multiple and complex mechanisms, which are deeply related. Therefore, compounds exerting neuroprotective effects through different pathways could present viable approaches in the management of neurodegenerative diseases, such as Alzheimer's and Parkinson's. In fact, several studies had already provided promising insights into the neuroprotective effects of a series of compounds isolated from different macroalgae species. This review will focus on compounds from macroalgae that exhibit neuroprotective effects and their potential application to treat and/or prevent neurodegenerative diseases.

Protective role of Spirulina platensis against acute deltamethrin-induced toxicity in rats

Deltamethrin is a broad-spectrum synthetic pyrethroid insecticide and acaricide widely used for agricultural and veterinary purposes. However, its human and animal exposure leads to hepatonephrotoxicity. Therefore, the present study was undertaken to examine the hepatonephroprotective and antioxidant potential of Spirulina platensis against deltamethrin toxicity in male Wistar albino rats. Deltamethrin treated animals revealed a significant increase in serum biochemical parameters as well as hepatic and renal lipid peroxidation but caused an inhibition in antioxidant biomarkers. Spirulina normalized the elevated serum levels of AST, ALT, APL, uric acid, urea and creatinine. Furthermore, it reduced deltamethrin-induced lipid peroxidation and oxidative stress in a dose dependent manner. Therefore, it could be concluded that spirulina administration able to minimize the toxic effects of deltamethrin by its free radical-scavenging and potent antioxidant activity.

Recent developments in production and biotechnological applications of C-phycocyanin

An extensive range of pigments including phycobiliproteins are present in algae. C-phycocyanin (C-PC), a phycobiliprotein, is one of the key pigments of Spirulina, a microalgae used in many countries as a dietary supplement. Algal pigments have massive commercial value as natural colorants in nutraceutical, cosmetics, and pharmaceutical industries, besides their health benefits. At present, increasing awareness of harmful effects of synthetic compounds and inclination of community towards the usage of natural products have led to the exploitation of microalgae as a source of natural pigments/colors. This review describes recent findings about the sources and production of C-PC, with emphasis on specific techniques for extraction and purification, along with potential industrial applications in diagnostics, foods, cosmetics, and pharmaceutical industries.

The effect of occupational lead exposure on lipid peroxidation, protein carbonylation, and plasma viscosity

The aim of the study was to investigate the influence of occupational lead (Pb) exposure on lipid peroxidation, protein carbonylation, and plasma viscosity in workers. The examined group included 283 healthy male employees of manufacturing facilities using zinc and Pb. The mean blood concentrations of Pb and zinc protoporphyrin as well as the mean urine δ-aminolevulinic acid levels were used as markers of exposure for the examined group. Taking into account the obtained mean values of blood lead level, the examined group was divided into three subgroups. When comparing the control group with the subgroups, Pb exposure markers were significantly elevated in all the three subgroups. Concentrations of conjugated dienes (CD), lipid hydroperoxides, malondialdehyde (MDA), and protein carbonyl groups were also significantly increased. Conversely, the levels of total protein and protein sulfhydryls were significantly decreased in the subgroups compared with the controls. The plasma viscosity was significantly elevated in the subgroups. A dose-response between Pb levels and plasma viscosity was not observed. Pb supposedly elevates MDA and CD in a dose-dependent manner. In conclusion, occupational Pb exposure induces oxidative stress that results in lipid and protein damage. Moreover, Pb-induced oxidative stress is likely the primary factor that elevates plasma viscosity, despite decreased protein levels.

Anti-oxidative and anti-inflammatory effects of spirulina on rat model of non-alcoholic steatohepatitis

The pathogenesis of nonalcoholic steatohepatitis (NASH) remains unclear, but accumulating data suggest oxidative stress and the relationship between inflammation and immunity plays a crucial role. The aim of this study is to investigate the spirulina, which is a blue-green algae rich in proteins and other nutritional elements, and its component-phycocyanin effect on a rat model of NASH. NASH model rats were established by feeding male Wistar rats with choline-deficient high-fat diet (CDHF) and intermittent hypoxemia by sodium nitrite challenge after 5 weeks of CDHF. After experimental period of 10 weeks, blood and liver were collected to determine oxidative stress injuries and efficacies of spirulina or phycocyanin on NASH model rats. In the NASH model rats, increase in plasma liver enzymes and liver fibrosis, increases in productions of reactive oxygen species from liver mitochondria and from leukocytes, the activation of nuclear factor-kappa B, and the change in the lymphocyte surface antigen ratio (CD4(+)/CD8(+)) were observed. The spirulina and phycocyanin administration significantly abated these changes. The spirulina or phycocyanin administration to model rats of NASH might lessen the inflammatory response through anti-oxidative and anti-inflammatory mechanisms, breaking the crosstalk between oxidative stress and inflammation, and effectively inhibit NASH progression.

Protective effects of Spirulina maxima on hyperlipidemia and oxidative-stress induced by lead acetate in the liver and kidney

BACKGROUND

Oxidative damage has been proposed as a possible mechanism involved in lead toxicity, specially affecting the liver and kidney. Previous studies have shown the antioxidant effect of Spirulina maxima in several experimental models of oxidative stress. The current study was carried out to evaluate the antioxidant activity of Spirulina maxima against lead acetate-induced hyperlipidemia and oxidative damage in the liver and kidney of male rats. Control animals were fed on a standard diet and did not receive lead acetate (Control group). Experimental animals were fed on a standard laboratory diet with or without Spirulina maxima 5% in the standard laboratory diet and treated with three doses of lead acetate (25 mg each/weekly, intraperitoneal injection) (lead acetate with Spirulina, and lead acetate without Spirulina groups).

RESULTS

The results showed that Spirulina maxima prevented the lead acetate-induced significant changes on plasma and liver lipid levels and on the antioxidant status of the liver and kidney. On the other hand, Spirulina maxima succeeded to improve the biochemical parameters of the liver and kidney towards the normal values of the Control group.

CONCLUSIONS

It was concluded that Spirulina maxima has protective effects on lead acetate-induced damage, and that the effects are associated with the antioxidant effect of Spirulina.

Spirulina platensis protects against renal injury in rats with gentamicin-induced acute tubular necrosis

The present study was carried out to evaluate the renoprotective antioxidant effect of Spirulina platensis on gentamicin-induced acute tubular necrosis in rats. Albino-Wistar rats, (9male and 9 female), weighing approximately 250 g, were used for this study. Rats were randomly assigned to three equal groups. Control group received 0,9 % sodium chloride intraperitoneally for 7 days at the same volume as gentamicin group. Gentamicin group was treated intraperitoneally with gentamicin, 80 mg/kg daily for 7 days. Gentamicin+spirulina group received Spirulina platensis 1000 mg/kg orally 2 days before and 7 days concurrently with gentamicin (80 mg/kg i.p.). Nephrotoxicity was assessed by measuring plasma nitrite concentration, stabile metabolic product of nitric oxide with oxygen. Plasma nitrite concentration was determined by colorimetric method using Griess reaction. For histological analysis kidney specimens were stained with hematoxylin-eosin (HE) and periodic acid-Schiff (PAS) stain. Plasma nitrite concentration and the level of kidney damage were significantly higher in gentamicin group in comparison both to the control and gentamicin+spirulina group. Spirulina platensis significantly lowered the plasma nitrite level and attenuated histomorphological changes related to renal injury caused by gentamicin. Thus, the results from present study suggest that Spirulina platensis has renoprotective potential in gentamicin-induced acute tubular necrosis possibly due to its antioxidant properties.

The effects of Panax ginseng and Spirulina platensis on hepatotoxicity induced by cadmium in rats

Cadmium is an environmental and industrial cumulative pollutant that affects many organs, specially the liver. The protective effect of Spirulina platensis and Panax ginseng on cadmium-induced oxidative stress and hepatotoxicity was evaluated in adult female Wistar albino rats. At the end of the 1-month experimental period, all animals were fasted for 12h and liver samples were taken for the determination of malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and nitric oxide (NO) levels. S. platensis and P. ginseng treatments showed marked decrease lipid peroxidation and increase of the endogenous antioxidants levels. The cadmium-induced histopathological changes were also minimized with the tested extracts. These results suggest that S. platensis and P. ginseng might play a role in reducing the toxic effect of cadmium and its antioxidant properties seem to mediate such a protective effect.

Spirulina platensis protects against gentamicin-induced nephrotoxicity in rats

The present study aimed to investigate the protective effect of Spirulina platensis (SP) on gentamicin sulphate (GS)-induced changes in the levels of lipid peroxidation and endogenous antioxidants in the kidney of rats. Sprague-Dawley rats were treated in separate groups as follows for 7 consecutive days: control (C), gentamicin sulphate (100 mg/kg i.p.) (GS), Spirulina platensis (1000 mg/kg orally) (SP) and Spirulina platensis (1000 mg/kg orally) plus gentamicin sulphate (100 mg/kg i.p.) (SP + GS). The degree of protection was evaluated by determining the effects of Spirulina platensis on malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPX) and nitric oxide (NO), and plasma creatinine and urea levels were estimated in kidney homogenates to evaluate antioxidant activity, and the kidney was histologically examined as well. Spirulina platensis elicited significant nephroprotective activity by decreasing lipid peroxidation (MDA) and elevated the levels of GSH, SOD, GPX, NO, creatinine and urea. Furthermore, these biochemical observations were supplemented by histological examination of the rat kidneys. In conclusion, the present study indicates a very important role of reactive oxygen species (ROS) and the relation to renal dysfunction and point to the therapeutic potential of Spirulina platensis in gentamicin sulphate induced nephrotoxicity.

Antioxidant potential of selected Spirulina platensis preparations

Recent studies suggest that Spirulina, a unicellular blue-green alga, may have a variety of health benefits and therapeutic properties and is also capable of acting as an antioxidant and antiinflammatory agent. In this study, a cell-free and a cell-based test assay were used to examine the antioxidant and antiinflammatory properties of four selected Spirulina platensis preparations: (1) Biospirulina, (2) SpiruComplex, a preparation with naturally bound selenium, chromium and zinc, (3) SpiruZink, a preparation with naturally bound zinc, (4) Zinkspirulina + Acerola, a preparation with naturally bound zinc and acerola powder. The cell-free test assay used potassium superoxide as a donor for superoxide radicals, whereas the cell-based test assay used the formation of intracellular superoxide radicals of functional neutrophils upon stimulation by phorbol-12-myristate-13-acetate as a model to investigate the potential of Spirulina preparations to inactivate superoxide radicals. In accordance with the recommended daily dosage, test concentrations ranging from 50 to 1000 microg/mL were chosen. The results showed a dose-dependent inactivation of free superoxide radicals (antioxidant effect) as well as an antiinflammatory effect characterized by a dose-dependent reduction of the metabolic activity of functional neutrophils and a dose-dependent inactivation of superoxide radicals generated during an oxidative burst. The results demonstrate that the tested Spirulina preparations have a high antioxidant and antiinflammatory potential. Especially SpiruZink and Zinkspirulina + Acerola might be useful as a supportive therapeutic approach for reducing oxidative stress and/or the generation of oxygen radicals in the course of inflammatory processes.

Neuroprotection by Spirulina platensis protean extract and phycocyanin against iron-induced toxicity in SH-SY5Y neuroblastoma cells

We investigated the effect of Spirulina platensis protean extract and the biliprotein phycocyanin isolated from this microalga, on the activities of the antioxidant enzymes SOD, CAT, GPx, and GR, lipid peroxidation inhibitory activity and glutathione levels after the iron induced oxidative stress in SH-SY5Y neuroblastoma cells. Iron is one of the most important agents that produce oxidative stress and decline of neuronal functions. S. platensis protean extract and phycocyanin exert the antioxidant activity by protecting the activity of the cellular antioxidant enzymes total GPx, GPx-Se and GR and by increasing reduced glutathione in cells against oxidative stress induced by iron. These results suggested that S. platensis protean extract is a powerful antioxidant through a mechanism related to antioxidant activity, capable of interfering with radical-mediated cell death. S. platensis may be useful in diseases known to be aggravated by reactive oxygen species and in the development of novel treatments for neurodegenerative disorders as long as iron has been implicated in the neuropathology of several neurodegenerative disorders such as Alzheimer's or Parkinson diseases.

''Iatrogenic Gilbert syndrome''--a strategy for reducing vascular and cancer risk by increasing plasma unconjugated bilirubin

The catabolism of heme, generating biliverdin, carbon monoxide, and free iron, is mediated by heme oxygenase (HO). One form of this of this enzyme, heme oxygenase-1, is inducible by numerous agents which promote oxidative stress, and is now known to provide important antioxidant protection, as demonstrated in many rodent models of free radical-mediated pathogenesis, and suggested by epidemiology observing favorable health outcomes in individuals carrying high-expression alleles of the HO-1 gene. The antioxidant impact of HO-1 appears to be mediated by bilirubin, generated rapidly from biliverdin by ubiquitously expressed biliverdin reductase. Bilirubin efficiently scavenges a wide range of physiological oxidants by electron donation. In the process, it is often reconverted to biliverdin, but biliverdin reductase quickly regenerates bilirubin, thereby greatly boosting its antioxidant potential. There is also suggestive evidence that bilirubin inhibits the activity or activation of NADPH oxidase. Increased serum bilirubin is associated with reduced risk for atherogenic disease in epidemiological studies, and more limited data show an inverse correlation between serum bilirubin and cancer risk. Gilbert syndrome, a genetic variant characterized by moderate hyperbilirubinemia attributable to reduced hepatic expression of the UDP-glucuronosyltransferase which conjugates bilirubin, has been associated with a greatly reduced risk for ischemic heart disease and hypertension in a recent study. Feasible strategies for boosting serum bilirubin levels may include administration of HO-1 inducers, supplementation with bilirubin or biliverdin, and administration of drugs which decrease the efficiency of hepatic bilirubin conjugation. The well-tolerated uricosuric drug probenecid achieves non-competitive inhibition of hepatic glucuronidation reactions by inhibiting the transport of UDP-glucuronic acid into endoplasmic reticulum; probenecid therapy is included in the differential diagnosis of hyperbilirubinemia, and presumably could be used to induce an ''iatrogenic Gilbert syndrome''. Other drugs, such as rifampin, can raise serum bilirubin through competitive inhibition of hepatocyte bilirubin uptake--although unfortunately rifampin is not as safe as probenecid. Measures which can safely achieve moderate serum elevations of bilirubin may prove to have value in the prevention and/or treatment of a wide range of disorders in which oxidants play a prominent pathogenic role, including many vascular diseases, cancer, and inflammatory syndromes. Phycobilins, algal biliverdin metabolites that are good substrates for biliverdin reductase, may prove to have clinical antioxidant potential comparable to that of bilirubin.

Renoprotective effect of Spirulina fusiformis on cisplatin-induced oxidative stress and renal dysfunction in rats

Cisplatin is an effective chemotherapeutic agent used in the treatment of a wide array of both pediatric and adult malignancies. Dose-dependent and cumulative nephrotoxicity is the major toxicity of this compound, sometimes requiring a reduction in dose or discontinuation of treatment. Recent evidences have implicated oxidative and nitrosative stress in cisplatin-induced nephrotoxicity. Spirulina fusiformis, blue-green algae, is claimed to be a potential antioxidant. The present study was designed to explore the renoprotective potential of Spirulina fusiformis against cisplatin-induced oxidative stress and renal dysfunction. Spirulina fusiformis (500,1000,1500 mg/kg(-1) p.o.) was administered 2 days before and until 3 days after cisplatin challenge (5 mg/kg(-1) i.p.). Renal injury was assessed by measuring serum creatinine, blood urea nitrogen, creatinine and urea clearance, and serum nitrite levels. Renal oxidative stress was determined by renal TBARS levels, reduced glutathione levels, and by enzymatic activity of superoxide dismutase and catalase. A single dose of cisplatin produced marked renal oxidative and nitrosative stress and significantly deranged renal functions. Chronic Spirulina fusiformis treatment significantly and dose-dependently restored renal functions, reduced lipid peroxidation, and enhanced reduced glutathione levels, superoxide dismutase, and catalase activities. The results of the present study clearly demonstrate the pivotal role of reactive oxygen species and their relation to renal dysfunction and point to the therapeutic potential of Spirulina fusiformis in cisplatin-induced nephrotoxicity.

Spirulina attenuates cyclosporine-induced nephrotoxicity in rats

Cyclosporine (CsA) causes a dose-related decrease in renal function in experimental animals and humans. The generation of reactive oxygen species (ROS) has been implicated in CsA-induced nephrotoxicity. It was previously shown that Spirulina, a blue-green algae, with antioxidant properties effectively attenuated the doxorubicin-induced cardiotoxicity in mice and cisplatin-induced nephrotoxicity in rat. The present study investigated the nephroprotective role of Spirulina against CsA-induced nephrotoxicity in rats. Spirulina (500 mg kg(-1) b.w.) was administered orally for 3 days before and 14 days concurrently with CsA (50 mg kg-1 b.w.). Rats treated with CsA showed nephrotoxicity as evidenced from a significant elevation in plasma urea, creatinine, urinary N-acetyl-beta-D-glucosaminidase (beta-NAG) and a decrease in creatinine and lithium clearance. Pretreatment with Spirulina protected the rats from CsA-induced nephrotoxicity. The CsA-induced rise in plasma urea and creatinine and the decrease in creatinine and lithium clearance were attenuated by Spirulina. There was a significant increase in plasma and kidney tissue MDA with CsA. Spirulina prevented the rise in plasma and kidney tissue MDA. Histopathology of the kidney from CsA-treated rats showed severe isometric vacuolization and widening of the interstitium. However, pretreatment with Spirulina prevented such changes, and the kidney morphology was comparable to that of the control. Spirulina treatment did not alter the blood CsA levels. These results suggest that Spirulina has a protective effect against nephrotoxicity induced by CsA. This study further supports the crucial role of the antioxidant nature of Spirulina in protecting against CsA-induced oxidative stress.

Effect of Spirulina, a blue green algae, on gentamicin-induced oxidative stress and renal dysfunction in rats

Gentamicin (GM), an aminoglycoside, is widely employed in clinical practice for the treatment of serious Gram-negative infections. The clinical utility of GM is limited by the frequent incidence of acute renal failure. Experimental evidences suggest that oxidative and nitrosative stress play an important role in GM nephrotoxicity. Spirulina fusiformis is a blue green algae with potent free radical scavenging properties. The present study was designed to investigate renoprotective potential of S. fusiformis, against GM-induced oxidative stress and renal dysfunction. Spirulina fusiformis (500, 1000, 1500 mg/kg, p.o.) was administered 2 days before and 8 days concurrently with GM (100 mg/kg, i.p.). Renal injury was assessed by measuring serum creatinine, blood urea nitrogen and creatinine clearance and serum nitrite levels. Renal oxidative stress was determined by renal malondialdehyde levels, reduced glutathione levels and by enzymatic activity of superoxide dismutase (SOD) and catalase. Chronic GM administration resulted in marked renal oxidative and nitrosative stress and significantly deranged renal functions. Treatment with S. fusiformis significantly and dose-dependently restored renal functions, reduced lipid peroxidation and enhanced reduced glutathione levels, SOD and catalase activities. The results of present study clearly demonstrate the pivotal role of reactive oxygen species and their relation to renal dysfunction and point to the therapeutic potential of S. fusiformis in GM-induced nephrotoxicity.

Protective effect of volatile oil, alcoholic and aqueous extracts of Origanum majorana on lead acetate toxicity in mice

Natural dietary antioxidants are extensively studied for their ability to protect cells from miscellaneous damages. Origanum majorana L., Lamiaceae, is a potent antioxidant. The effect of administration of O. majorana (volatile oil, alcoholic and aqueous extracts) on oral administration of lead acetate in the diet of mice at concentration 0.5% (W/W) for one month were studied by measuring serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), urea and creatinine, histopathological changes of the liver and kidney and genotoxicity including, rate of micronucleus and chromosomal aberrations in bone marrow cells. Mice were treated with the 3 different forms of O. majorana, one month before and maintained with lead acetate administration. The 3 forms of O. majorana induced a significant decrease in serum activities of transaminases (AST & ALT), ALP, urea and creatinine and improved the liver and kidney histology in comparison with lead acetate treated group. Alcoholic extracts of O. majorana significantly reduced the rate of micronucleus, number of aberrant cells and different kinds of chromosomal aberrations. Volatile oil extract significantly reduced the rate of micronucleus and chromosomal fragments. Aqueous extract and volatile oil also of O. majorana significantly reduced number of gaps, ring chromosome and stickiness. It could be concluded that O. majorana plays an important role in ameliorating liver and kidney functions and genotoxicity induced by lead toxicity.

Effects of spirulina on the number of ovary mast cells in lead-induced toxicity in rats

The present study investigated the protective effect of Spirulina against the lead-induced increase in mast cells in the ovary during the oestrous cycle of rats. In the ovary cortex and medulla of lead-exposed animals, there was a significant increase in the number of mast cells; however, when also treated with Spirulina, a decrease was observed. The number of mast cells when Spirulina (300 mg/kg) was used alone was not significantly different from that of the control group. These results indicate that Spirulina decreases the number of mast cells induced by lead in the cortex and medulla of rat ovary.

Melatonin protects against lead-induced hepatic and renal toxicity in male rats

The present study was designed to investigate the potential protective effect of melatonin against the hepatic and renal toxicity of lead in male rats. Three groups of animals were used in this study (control, lead acetate-treated (100 mg/kg), and lead acetate plus melatonin (10 mg/kg) for 30 days. Levels of lipid peroxidation (LPO) products, superoxide dismutase (SOD) activity, total glutathione (GSH), histopathological changes in the liver and kidneys were investigated. In addition, nuclear area (NA), nuclear volume (NV) and the ratio of nuclear volume/cellular volume (N/C) were measured in the liver. The results revealed increased LPO and decreased SOD, GSH, NA, NV and N/C in the studied organs of lead-treated rats. Histopathological observations showed severe damage in the liver and kidneys. Melatonin co-treatment to the lead-administered rats attenuated the increase of LPO and restored the activity of SOD and levels of GSH as well as the mean values of NA, NV and N/C. Also, the morphological damage in the liver and kidneys was reduced and the tissues appeared like those of controls. The present study suggests that melatonin may be useful in combating free radical-induced damage due to lead toxicity.

Effects of a Spirulina-based dietary supplement on cytokine production from allergic rhinitis patients

Spirulina represents a blue-green alga that is widely produced and commercialized as a dietary supplement for modulating immune functions, as well as ameliorating a variety of diseases. We have previously shown that the in vitro culture of Spirulina with human peripheral blood mononuclear cells (PBMCs) modulated the production of cytokines. In the present study, we evaluated the impact of a Spirulina-based dietary supplement (Earthrise Nutritionals, Inc., Irvine, CA) on patients with allergic rhinitis by assessing the production of cytokines [interleukin (IL)-4, interferon (IFN)-gamma, and IL-2] critical in regulating immunoglobulin E-mediated allergy. In a randomized double-blinded crossover study versus placebo, allergic individuals were fed daily with either placebo or Spirulina, at 1,000 mg or 2,000 mg, for 12 weeks. PBMCs isolated before and after the Spirulina feeding were stimulated with phytohemagglutinin (PHA) prior to determining the levels of cytokine from cell culture supernatants. Although Spirulina seemed to be ineffective at modulating the secretion of Th1 cytokines (IFN-gamma and IL-2), we discovered that Spirulina, administered at 2,000 mg/day, significantly reduced IL-4 levels by 32% from PHA-stimulated cells. These results indicate that Spirulina can modulate the Th profile in patients with allergic rhinitis by suppressing the differentiation of Th2 cells mediated, in part, by inhibiting the production of IL-4. To our knowledge, this is the first human feeding study that demonstrates the protective effects of Spirulina towards allergic rhinitis.

Radioprotection by plant products: present status and future prospects

The development of radioprotective agents has been the subject of intense research in view of their potential for use within a radiation environment, such as space exploration, radiotherapy and even nuclear war. However, no ideal, safe synthetic radioprotectors are available to date, so the search for alternative sources, including plants, has been on going for several decades. In Ayurveda, the traditional Indian system of medicine, several plants have been used to treat free radical-mediated ailments and, therefore, it is logical to expect that such plants may also render some protection against radiation damage. A systematic screening approach can provide leads to identifying potential new candidate drugs from plant sources, for mitigation of radiation injury. This article reviews some of the most promising plants, and their bioactive principles, that are widely used in traditional systems of medicine, and which have rendered significant radioprotection in both in vitro and in vivo model systems. Plants and their constituents with pharmacological activities that may be relevant to amelioration of radiation-mediated damage, including antiemetic, antiinflammatory, antioxidant, cell proliferative, wound healing and haemopoietic stimulatories are also discussed.

Antioxidant and antiproliferative activities of Spirulina and Chlorella water extracts

Liver fibrosis is a chronic liver disease that will further develop to cirrhosis if severe damage continues to form. A potential treatment for liver fibrosis is to inhibit activated hepatic stellate cell (HSC) proliferation and, subsequently, to induce HSC apoptosis. It has been reported that antioxidants are able to inhibit the proliferation of HSCs. In this study, the aqueous extract of spirulina was chosen as the source of antioxidant to investigate the inhibitory effect on the proliferation of HSC. The growth inhibitory effects of aqueous spirulina and chlorella extract on human liver cancer cells, HepG2, were also studied and compared in pairs. Results indicated that the total phenol content of spirulina was almost five times greater than that of chlorella (6.86 +/- 0.58 vs 1.44 +/- 0.04 mg tannic acid equivalent/g of algae powder, respectively). The antioxidant activity of spirulina determined by the ABTS*+ method was higher than chlorella (EC50: 72.44 +/- 0.24 micromol of trolox equivalent/g of spirulina extract vs 56.09 +/- 1.99 micromol of trolox equivalent/g of chlorella extract). Results of DPPH* assay also showed a similar trend as the ABTS*+ assay (EC50: 19.39 +/- 0.65 micromol of ascorbic acid equivalent/g of spirulina extract vs 14.04 +/- 1.06 micromol of ascorbic acid equivalent/g of chlorella extract). The aqueous extracts of these two algae both showed antiproliferative effects on HSC and HepG2, but spirulina was a stronger inhibitor than chlorella. Annexin-V staining showed that aqueous extract of spirulina induced apoptosis of HSC after 12 h of treatment. In addition, the aqueous extract of spirulina triggered a cell cycle arrest of HSC at the G2/M phase.

Medicinal herbal extracts - renal friend or foe? Part two: Herbal extracts with potential renal benefits

In this second of two articles regarding the renal toxicities or benefits of medicinal herbs, herbs are reported as being 'potentially beneficial' to the kidneys if there is strong in vivo evidence of renal protection from toxic substances or drugs; potent, specific renal anti-oxidant effects; in vivo cancer antiproliferative effects specific to the kidneys; or in vivo evidence of being beneficial in renal disease or failure. Among the herbs, polyherbal formulae and fungi with potential renal benefits are Cordyceps sinensis, Sairei-to, Rheum spp., Salvia miltiorrhiza and its component, magnesium lithospermate B and others.