Spirulina maxima prevents fatty liver formation in CD-1 male and female mice with experimental diabetes

Spirulina reduces diet-induced obesity through downregulation of lipogenic genes expression in Psammomys obesus

The present study evaluates the protective effect of spirulina against diet-induced obesity and metabolic disorders in Psammomys obesus, an animal model of metabolic syndrome. Psammomys obesus lives on a low-energy diet, in order to remain healthy. However, under a standard laboratory chow diet (SLCD), this animal exhibits insulin resistance, which occurs as a result of obesity. Psammomys obesus was maintained on SLCD, in order to evaluate the effect of spirulina on obesity development with a particular focus on glucose and lipid metabolism, as well as the mRNA expression of some pro-inflammatory cytokines. After 12 weeks of treatment with spirulina, there was a significant reduction in body weight gain, plasma glucose, insulin and triglyceride levels. There was also a significant reduction in the mRNA expression of genes involved in lipogenesis and inflammation. Spirulina improved insulin sensitivity, glucose and lipid metabolism. These findings highlight the positive effect of spirulina on weight maintenance.

Effect of Microalgae Arthrospira on Biomarkers of Glycemic Control and Glucose Metabolism: A Systematic Review and Meta-analysis

Diabetes mellitus and insulin resistance are associated with an increased risk of cardiovascular disease (CVD) incidence and a higher rate of CVD-related death. In this study, the effects of Arthrospira (Spirulina) a blue-green algae supplementation on biomarkers of glycemic control and glucose metabolism has been evaluated. PubMed, Scopus, and ISI Web of Science were searched systematically of English human subjects and PubMed for pre-clinical animal studies (rats and mice) from January 2008 until November 2020. The pooled weighted mean difference (MD) and its 95% confidence interval (CI) were calculated and pooled using a random-effect model. Seven clinical and 27 preclinical studies were included. Pooled results of the clinical studies showed that Arthrospira supplementation significantly reduced the fasting blood sugar (FBS): (0.63- 2.90-) 1.77-, total cholesterol (TC): (0.46- ، 4.61-) 2.54-, triglycerides (TG): (0.89- ، 6.54-) 3.71- and increased the high-density lipoprotein cholesterol (HDL-C): (3.86 ، 0.67) 2.27; however, Arthrospira was not significantly effective in terms of reducing the glycated hemoglobin A1c (HbA1C): (1.04 ، 2.23-) 0.59- and low-density lipoprotein cholesterol (LDL-C). Pooled results of preclinical studies showed that Arthrospira supplementation reduced FBS [-10.31 (-12.49, -8.13)] and HbA1C [-5.12 (-8.06, -2.19)] significantly in diabetic animals. Sub-group analysis of clinical studies showed that intervention duration less than 2 months [-2.52 (-4.37, -0.67)] and the dose less than 2 gram [-3.22 (-5.67, -0.76)] showed significant improvement in terms of reducing the FBS in humans. It can be concluded that Arthrospira can be considered as an effective FBS, TG, TC, and HDL-C adjusting nutraceutical agent for diabetes mellitus. Due to the differences in the results of clinical and animal studies in terms of HbA1c, more studies are needed for a definitive conclusion.

Spirulina liquid extract prevents metabolic disturbances and improves liver sphingolipids profile in hamster fed a high-fat diet

PURPOSE

Metabolic syndrome is characterized by hyperglycemia, hyperlipemia and exacerbated oxidative stress. The aim of the study was to determine whether Spirulysat^®, a Spirulina liquid extract (SLE) enriched in phycocyanin, would prevent metabolic abnormalities induced by high-fat diet.

METHODS

The effect of acute SLE supplementation on postprandial lipemia and on triton-induced hyperlipidemia was studied in hamster fed control diet (C). The effect of chronic SLE supplementation on lipid content in plasma, liver and aorta, and on glycemia and oxidative stress was studied in hamster fed control (C) or high-fat diet (HF) for two weeks and then treated with SLE for two weeks (CSp and HFSp) or not (C and HF).

RESULTS

The acute SLE supplementation lowered plasma cholesterol and non-esterified fatty acid concentrations after olive oil gavage (P < 0.05) in CSp, while no effect was observed on triglyceridemia. HFD increased plasma MDA, basal glycemia, triglyceridemia, total plasma cholesterol, VLDL, LDL and HDL cholesterol, ceramide, sphingomyelin and glucosylceramide content in liver in HF compared to C (P < 0.05). SLE did not affect SOD and GPx activities nor total antioxidant status in HFSp group but lowered glycemia, glucoceramide and cholesterol in liver and cholesterol in aorta compared to HF (P < 0.05). SLE also decreased HMGCoA and TGF-β1 gene expression in liver (P < 0.05) and tended to lower G6Pase (P = 0.068) gene expression in HFSp compared to HF.

CONCLUSION

Although 2-week SLE supplementation did not affect oxidative stress, it protected from hyperglycemia and lipid accumulation in liver and aorta suggesting a protective effect against metabolic syndrome.

Effects of spirulina on weight loss and blood lipids: a review

Spirulina, a cyanobacteria commonly referred to as a blue-green algae, is one of the oldest lifeforms on Earth. Spirulina grows in both fresh and saltwater sources and is known for its high protein and micronutrient content. This review paper will cover the effects of spirulina on weight loss and blood lipids. The currently literature supports the benefits of spirulina for reducing body fat, waist circumference, body mass index and appetite and shows that spirulina has significant benefits for improving blood lipids.

Spirulina maxima extract prevents cell death through BDNF activation against amyloid beta 1-42 (Aβ1-42) induced neurotoxicity in PC12 cells

Spirulina maxima is a blue-green micro alga that contains abundant amounts of proteins (60-70%), vitamins, chlorophyll a, and C-phycocyanin (C-PC). It has been shown to reduce oxidative stress, and prevent diabetes and non-alcoholic fatty liver disease. However, it is unclear whether Spirulina maxima 70% ethanol extract (SM70EE), chlorophyll a, and C-PC prevent Aβ_1-42-induced neurotoxicity in PC12 cells. The aim of this study was to investigate whether SM70EE, chlorophyll a, and C-PC prevent Aβ_1-42-induced cell death. SM70EE, chlorophyll a, and C-PC suppressed the Aβ_1-42-induced increase in poly-ADP ribose polymerase-1 (PARP-1) cleavage and reduced Aβ_1-42-induced decreases in glutathione and its associated factors. The level of brain-derived neurotrophic factor (BDNF), which plays a critical role in neuronal survival and neuroprotection, was increased by SM70EE, chlorophyll a, and C-PC in Aβ_1-42-treated cells. SM70EE treatment decreased oxidative stress and cell death in response to Aβ_1-42 treatment, while simultaneously suppressing PARP cleavage and increasing the levels of glutathione (GSH) and its associated factors. Moreover, SM70EE lowered the levels of APP and BACE1, two major factors involved in APP processing, and increased BDNF expression during Aβ_1-42-induced neurotoxicity in PC12 cells. We suggest that SM70EE prevents cell death caused by Aβ_1-42 -induced neurotoxicity via the activation of BDNF signaling.

Spirulina maxima Extract Ameliorates Learning and Memory Impairments via Inhibiting GSK-3β Phosphorylation Induced by Intracerebroventricular Injection of Amyloid-β 1-42 in Mice

Spirulina maxima, a microalga containing high levels of protein and many polyphenols, including chlorophyll a and C-phycocyanin, has antioxidant and anti-inflammatory therapeutic effects. However, the mechanisms where by Spirulina maxima ameliorates cognitive disorders induced by amyloid-β 1–42 (Aβ_1–42) are not fully understood. In this study, we investigated whether a 70% ethanol extract of Spirulina maxima (SM70EE) ameliorated cognitive impairments induced by an intracerebroventricular injection of Aβ_1–42 in mice. SM70EE increased the step-through latency time in the passive avoidance test and decreased the escape latency time in the Morris water maze test in Aβ_1–42-injected mice. SM70EE reduced hippocampal Aβ_1–42 levels and inhibited amyloid precursor protein processing-associated factors in Aβ_1–42-injected mice. Additionally, acetylcholinesterase activity was suppressed by SM70EE in Aβ_1–42-injected mice. Hippocampal glutathione levels were examined to determine the effects of SM70EE on oxidative stress in Aβ_1–42-injected mice. SM70EE increased the levels of glutathione and its associated factors that were reduced in Aβ_1–42-injected mice. SM70EE also promoted activation of the brain-derived neurotrophic factor/phosphatidylinositol-3 kinase/serine/threonine protein kinase signaling pathway and inhibited glycogen synthase kinase-3β phosphorylation. These findings suggested that SM70EE ameliorated Aβ_1–42-induced cognitive impairments by inhibiting the increased phosphorylation of glycogen synthase kinase-3β caused by intracerebroventricular injection of Aβ_1–42 in mice.

Spirulina maxima Extract Prevents Neurotoxicity via Promoting Activation of BDNF/CREB Signaling Pathways in Neuronal Cells and Mice

Spirulina maxima is a microalgae which contains flavonoids and other polyphenols. Although Spirulina maxima 70% ethanol extract (SM70EE) has diverse beneficial effects, its effects on neurotoxicity have not been fully understood. In this study, we investigated the neuroprotective effects of SM70EE against trimethyltin (TMT)-induced neurotoxicity in HT-22 cells. SM70EE inhibited the cleavage of poly-ADP ribose polymerase (PARP). Besides, ROS production was decreased by down-regulating oxidative stress-associated enzymes. SM70EE increased the factors of brain-derived neurotrophic factor (BDNF)/cyclic AMP-responsive element-binding protein (CREB) signalling pathways. Additionally, acetylcholinesterase (AChE) was suppressed by SM70EE. Furthermore, we investigated whether SM70EE prevents cognitive deficits against scopolamine-induced neurotoxicity in mice by applying behavioral tests. SM70EE increased step-through latency time and decreased the escape latency time. Therefore, our data suggest that SM70EE may prevent TMT neurotoxicity through promoting activation of BDNF/CREB neuroprotective signaling pathways in neuronal cells. In vivo study, SM70EE would prevent cognitive deficits against scopolamine-induced neurotoxicity in mice.

Hyperglycemia, oxidative stress, liver damage and dysfunction in alloxan-induced diabetic rat are prevented by Spirulina supplementation

Medicinal plants have long been used against life-threatening diseases including diabetes, with more or less success. Some of these plants have been shown to possess antioxidant activities, which could help improving diabetes inconveniences. In that context, we investigated the effects of spirulina supplementation on alloxan-induced diabetic rats, hypothesizing that co-administration of spirulina with rat diet could ameliorate diabetes complications and provide as benefits as the common antidiabetic insulin. Following alloxan treatment, male Wistar rats were fed daily with 5% spirulina-enriched diet or treated with insulin (0.5 IU/rat) for 21 days. Both spirulina and insulin treatments of diabetic rats resulted in a significant reduction in fasting blood glucose and an increase of glycogen level. Spirulina supplementation also impeded loss of body weight and ameliorated hepatic toxicity indices, i.e. alkaline phosphatases and transaminases activities, bilirubin levels and lipid peroxidation. Besides, triglycerides, total cholesterol, and low-density lipoprotein cholesterol levels decreased in the serum. Moreover, diabetic rats fed with spirulina exhibited sig changes in antioxidant enzyme activities in the liver (ie, decrease in superoxide dismutase and increase in catalase and glutathione peroxidase activities). The beneficial effects of spirulina or insulin were confirmed by histological study of the liver of diabetic rats. Overall, this study indicates that treatment with spirulina decreased hyperglycemia and oxidative stress in diabetic rats, this amelioration being even more pronounced than that provided by insulin injection. Therefore, administration of this alga would be very helpful in the prevention of diabetic complications.

Development and Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Quantitation of Microcystins in Blue-Green Algal Dietary Supplements

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous detection and quantitation of seven microcystin congeners (1-7) and nodularin-R (8) in blue-green algal dietary supplements. Single-laboratory method validation data were collected in four supplement matrices (capsule, liquid, powder, and tablet) fortified at toxin concentrations from 0.25-2.00 μg/g (ppm). Average recoveries and relative standard deviations (RSD) using matrix-corrected solvent calibration curves were 101% (6% RSD) for all congeners and supplements investigated. Limits of detection (0.006-0.028 μg/g) and quantitation (0.018-0.084 μg/g) were sufficient to confirm the presence of microcystin contamination at the Oregon-mandated guidance concentration of 1.0 μg of microcystin-LReq/g. Quantitated concentrations of microcystin contamination in market-available Aphanizomenon flos-aquae blue-green algal supplements ranged from 0.18-1.87 μg of microcystin-LReq/g for detected congeners microcystin-LR, microcystin-LA, and microcystin-LY (3-5). Microcystin-RR, -YR, -LW, and -LF and nodularin-R (1, 2, and 6-8) were not detected in the supplements examined.

Selenium-enriched Spirulina protects INS-1E pancreatic beta cells from human islet amyloid polypeptide-induced apoptosis through suppression of ROS-mediated mitochondrial dysfunction and PI3/AKT pathway

PURPOSE

Human islet amyloid polypeptide (hIAPP) aggregation is linked to loss of pancreatic beta cells in type 2 diabetes, in part due to oxidative stress. Currently, little is known about the effects of selenium-enriched Spirulina on beta cells with the presence of hIAPP. In this study, INS-1E rat insulinoma cells were used as a model to evaluate in vitro protective effects of Se-enriched Spirulina extract (Se-SE) against hIAPP-induced cell death, as well as the underlying mechanisms.

METHODS

Flow cytometric analysis was used to evaluate cell apoptosis, mitochondrial membrane potential (ΔΨm) and ROS generation. Caspase activity was measured using a fluorometric method. Western blotting was applied to detect protein expression.

RESULTS

Our results showed that exposure of INS-1E cells to hIAPP resulted in cell viability loss, LDH release and appearance of sub-G peak. However, cytotoxicity of hIAPP was significantly attenuated by co-treatment with Se-SE. Se-SE also inhibited hIAPP-induced activation of caspase-3, -8 and -9. Additionally, hIAPP-induced accumulation of ROS and superoxide was suppressed by co-treatment with Se-SE. Moreover, Se-SE was able to prevent hIAPP-induced depletion of ΔΨm and intracellular ATP, reduction in mitochondrial mass, changes in the expression of Bcl-2 family members, release of mitochondrial apoptogenic factors. Furthermore, hIAPP-mediated AKT inhibition was restored by co-treatment with Se-SE.

CONCLUSION

Our results showed that Se-SE protects INS-1E cells from hIAPP-induced cell death through preventing ROS overproduction, mitochondrial dysfunction and modulating PI3K/AKT pathway.

Effects of Spirulina, a Blue-Green Alga, on Bone Metabolism in Ovariectomized Rats and Hindlimb-Unloaded Mice

The safety and effectiveness were examined of the spirulina alga on bone metabolism in ovariectomized estrogen-deficient rats and hindlimb-unloaded mice. The dosage range was from an amount equal to that recommended in so-called health foods for humans (0.08 g/kg BW/day) to a 100-fold higher dose. The bone mineral density (BMD) of the whole femur and tibia of ovariectomized rats in the any spirulina-treated groups was not significantly different from that of the ovariectomized group, although BMD of the distal femur and proximal tibia was significantly lower in the spirulina-treated groups than in the ovariectomized group after a 6 week-experimental period. BMD of the femur and tibia was not affected by treatment with any dose of spirulina in hindlimb-unloaded mice. These results suggest that the intake of spirulina decreased BMD in the trabecular bone of rodents under estrogen-deficient conditions.

Inhibitory effects of dietary Spirulina platensis on UVB-induced skin inflammatory responses and carcinogenesis

Reactive oxygen species produced in response to UVR are important in skin tumor development. We have previously reported that deficiency of the Ogg1 gene, encoding the repair enzyme for 8-oxo-7,8-dihydroguanine (8-oxoG), increases skin tumor incidence in mice upon repetitive UVB exposure and modulation of UVB-induced inflammatory response. Spirulina platensis is used as a human food supplement because it contains abundant nutritional and antioxidant components. Therefore, we investigated the inhibitory effects of S. platensis on UVB-induced skin tumor development in Ogg1 knockout-(KO) mice and the wild-type (WT) counterpart. Dietary S. platensis suppressed tumor induction and development in both genotypes compared with our previous data without S. platensis. Induction of erythema and ear swelling, one of the hallmarks of UVB-induced inflammatory responses, was suppressed in the skin of Ogg1-KO mice and albino hairless mice fed with dietary S. platensis. Compared with untreated mice, S. platensis-administered mice showed significantly reduced 8-oxoG formation in the skin after UVB exposure. Moreover, we found that S. platensis effectively downregulated the signal proteins p38 mitogen-activated protein kinase, stress-activated protein kinase/c-Jun N-terminal kinase, and extracellular signal-regulated kinase after UVB exposure especially in Ogg1-KO mice. Our results suggest that S. platensis exerts antitumor effects against UVB irradiation in the skin through its anti-inflammatory and antioxidant effects.

Effects of Long-Term Supplementation of Blue-Green Algae on Lipid Metabolism in C57BL/6J mice

Dyslipidemia is a primary risk factor for cardiovascular disease. In this study, we investigated the effect of long-term supplementation of two blue-green algae (BGA) species, i.e., Nostoc commune var. sphaeroides Kützing (NO) and Spirulina platensis (SP), on lipid metabolism in vivo. Male C57BL/6J mice were fed an AIN-93G/M diet supplemented with 2.5 or 5% (wt/wt) NO or SP for 6 months. Mice fed NO and SP showed lower plasma total cholesterol (TC) and triglyceride (TG) concentrations than control at certain months during 6 month experimental period. Both BGA supplementation for 6 months significantly increased hepatic TC contents whereas SP-fed groups had significantly less TG levels in the liver compared with control and NO groups. None of BGA-fed animals showed significantly different mRNA levels of sterol regulatory element binding protein 2, while 3-hydroxy-3-methylglutaryl coenzyme A reductase and low-density lipoprotein receptor (LDLR) expression was higher in NO groups than the other groups in the liver. Furthermore, NO supplementation increased the hepatic expression of acetyl-CoA carboxylase 1, stearoyl CoA desaturase 1, carnitine palmitoyltransferase 1α, and acyl-CoA oxidase 1 but SP did not elicit any significant changes in mRNA levels of the genes compared with control. LDLR protein level was significantly higher in NO 2.5% and SP 5%, as compared to the control and NO 5% groups; while the level of fatty acid synthase protein in the liver was significantly higher in NO 5% and SP 5%, than that in the control group. In conclusion, our results suggest that long-term supplementation of NO and SP decreased plasma TC and TG concentrations. Therefore, supplementation of NO and SP may be potentially beneficial for preventing dyslipidemia-associated chronic diseases.

Health benefits of blue-green algae: prevention of cardiovascular disease and nonalcoholic fatty liver disease

Blue-green algae (BGA) are among the most primitive life forms on earth and have been consumed as food or medicine by humans for centuries. BGA contain various bioactive components, such as phycocyanin, carotenoids, γ-linolenic acid, fibers, and plant sterols, which can promote optimal health in humans. Studies have demonstrated that several BGA species or their active components have plasma total cholesterol and triglyceride-lowering properties due to their modulation of intestinal cholesterol absorption and hepatic lipogenic gene expression. BGA can also reduce inflammation by inhibiting the nuclear factor κ B activity, consequently reducing the production of proinflammatory cytokines. Furthermore, BGA inhibit lipid peroxidation and have free radical scavenging activity, which can be beneficial for the protection against oxidative stress. The aforementioned effects of BGA can contribute to the prevention of metabolic and inflammatory diseases. This review provides an overview of the current knowledge of the health-promoting functions of BGA against cardiovascular disease and nonalcoholic fatty liver disease, which are major health threats in the developed countries.

Edible blue-green algae reduce the production of pro-inflammatory cytokines by inhibiting NF-κB pathway in macrophages and splenocytes

BACKGROUND

Chronic inflammation contributes to the development of pathological disorders including insulin resistance and atherosclerosis. Identification of anti-inflammatory natural products can prevent the inflammatory diseases.

METHODS

Anti-inflammatory effects of blue-green algae (BGA), i.e., Nostoc commune var. sphaeroides Kützing (NO) and Spirulina platensis (SP), were compared in RAW 264.7 and mouse bone marrow-derived macrophages (BMM) as well as splenocytes from apolipoprotein E knockout (apoE(-/-)) mice fed BGA.

RESULTS

When macrophages pretreated with 100μg/ml NO lipid extract (NOE) or SP lipid extract (SPE) were activated by lipopolysaccharide (LPS), expression and secretion of pro-inflammatory cytokines, such as tumor necrosis factor α (TNFα), interleukin 1β (IL-1β), and IL-6, were significantly repressed. NOE and SPE also significantly repressed the expression of TNFα and IL-1β in BMM. LPS-induced secretion of IL-6 was lower in splenocytes from apoE(-/-) fed an atherogenic diet containing 5% NO or SP for 12weeks. In RAW 264.7 macrophages, NOE and SPE markedly decreased nuclear translocation of NF-κB. The degree of repression of pro-inflammatory gene expression by algal extracts was much stronger than that of SN50, an inhibitor of NF-κB nuclear translocation. Trichostatin A, a pan histone deacetylase inhibitor, increased basal expression of IL-1β and attenuated the repression of the gene expression by SPE. SPE significantly down-regulated mRNA abundance of 11 HDAC isoforms, consequently increasing acetylated histone 3 levels.

CONCLUSION

NOE and SPE repress pro-inflammatory cytokine expression and secretion in macrophages and splenocytes via inhibition of NF-κB pathway. Histone acetylation state is likely involved in the inhibition.

GENERAL SIGNIFICANCE

This study underscores natural products can exert anti-inflammatory effects by epigenetic modifications such as histone acetylation.

[Spirulina, exercise and serum glucose control in diabetic rats]

OBJECTIVE

The objective of this study was to analyze the effect of Spirulina and/or exercise training in the control of serum glucose homeostasis in diabetic rats.

MATERIALS AND METHODS

Young Wistar rats were induced to diabetes by intravenous alloxan administration and separated into four groups: diabetic control (DC), diabetic Spirulina (DS), diabetic exercise (DE) and diabetic exercise Spirulina (DES).

RESULTS

There were no differences between groups with respect to: body weight, food intake, glucose tolerance, insulin tolerance and blood lactate concentrations during a swimming effort test. DS group showed lower insulin concentrations when compared with DC (pancreas) and DE and DES (serum).

CONCLUSION

The protocols of exercise and supplementation with Spirulina used in the present study were not able to improve serum glucose homeostasis in diabetic rats.

Contamination by Microcystis and microcystins of blue-green algae food supplements (BGAS) on the Italian market and possible risk for the exposed population

Blue green algae supplements (BGAS) are generally proposed as health-promoting natural products for their purported beneficial effects. Spirulina spp. and Aphanizomenon flos aquae are mainly used in BGAS production. They are usually collected from the natural environment, where other potentially toxic cyanobacteria can be present, making possible BGAS contamination by cyanotoxins, with potential risk for human health. In this work we apply a combined approach, by using chemical and molecular techniques, on BGAS of 17 brands available in Italy. Samples containing Spirulina-only were free of contamination. The Aphanizomenon flos aquae-based samples were contaminated by highly variable levels of microcystins (MC-LR and MC-LA congeners), up to 5.2 μg MC-LR equivalents per gram product. The highest variability (up to 50 fold) was among batches of the same brand, although intra-batch differences were also evidenced. PCR analyses were positive only for the presence of Microcystis sp., identified as the toxin-producing species responsible for contamination. At the maximum contamination levels found, a risk for consumers can be expected following chronic or sub-chronic exposure to a reasonable daily BGAS consumption of 4 g. The need for a strict monitoring by producers and Health Authority to assure an adequate protection for consumers is underscored.

Spirulina improves non-alcoholic steatohepatitis, visceral fat macrophage aggregation, and serum leptin in a mouse model of metabolic syndrome

BACKGROUND

Nutritional approaches are sought to overcome the limits of pioglitazone in metabolic syndrome and non-alcoholic fatty liver disease. Spirulina, a filamentous unicellular alga, reduces serum lipids and blood pressure while exerting antioxidant effects.

AIM

To determine whether Spirulina may impact macrophages infiltrating the visceral fat in obesity characterizing our metabolic syndrome mouse model induced by the subcutaneous injection treatment of monosodium glutamate.

METHODS

Mice were randomized to receive standard food added with 5% Spirulina, 0.02% pioglitazone, or neither. We tested multiple biochemistry and histology (both liver and visceral fat) readouts at 24 weeks of age.

RESULTS

Data demonstrate that both the Spirulina and the pioglitazone groups had significantly lower serum cholesterol and triglyceride levels and liver non-esterified fatty acid compared to untreated mice. Spirulina and pioglitazone were associated with significantly lower leptin and higher levels, respectively, compared to the control group. At liver histology, non-alcoholic fatty liver disease activity score and lipid peroxide were significantly lower in mice treated with Spirulina.

CONCLUSIONS

Spirulina reduces dyslipidaemia in our metabolic syndrome model while ameliorating visceral adipose tissue macrophages. Human studies are needed to determine whether this safe supplement could prove beneficial in patients with metabolic syndrome.

Exercise and spirulina control non-alcoholic hepatic steatosis and lipid profile in diabetic Wistar rats

BACKGROUND

Diabetes mellitus is associated with metabolic dysfunctions, including alterations in circulating lipid levels and fat tissue accumulation, which causes, among other pathologies, non-alcoholic fatty liver disease (NAFLD).

AIM OF THE STUDY

The objective of this study was to analyse the effects of physical exercise and spirulina intake on the control of NAFLD in diabetic Wistar rats.

METHODS

Diabetes was induced in the animals through intravenous administration of alloxan. The rats were divided into four groups: Diabetic Control (DC) - diabetic rats fed with a control diet and no physical exercise; Diabetic Spirulina (DS) - diabetic rats fed with a diet that included spirulina; Diabetic Spirulina and Exercise (DSE) - diabetic rats fed with a diet that included Spirulina and that exercised; and Diabetic Exercise (DE) - diabetic rats fed with a control diet and that exercised.

RESULTS

The groups DS, DSE, and DE presented lower plasma concentrations of LDL cholesterol than DC, as well as lower levels of total liver lipids in groups DS, DSE, and DE in comparison to DC.

CONCLUSION

Thus, spirulina appears to be effective in reducing total circulating levels of LDL-cholesterol and hepatic lipids, alone or in conjunction with physical exercise in diabetic rats.

In vitro and in vivo safety assessment of edible blue-green algae, Nostoc commune var. sphaeroides Kützing and Spirulina plantensis

Blue-green algae (BGA) have been consumed as food and herbal medicine for centuries. However, safety for their consumption has not been well investigated. This study was undertaken to evaluate in vitro and in vivo toxicity of cultivated Nostoc commune var. sphaeroides Kützing (NO) and Spirulina platensis (SP). Neither NO nor SP contained detectable levels of microcystin (MC)-LA, MC-RR, MC-LW and MC-LR by LC/MS/MS. Cell viability remained ∼70-80% when HepG2 cells were incubated with 0-500 μg/ml of hexane, chloroform, methanol and water-extractable fractions of NO and SP. Four-week-old male and female C57BL/6J mice were fed an AIN-93G/M diet supplemented with 0%, 2.5% or 5% of NO and SP (wt/wt) for 6 months. For both genders, BGA-rich diets did not induce noticeable abnormality in weight gain and plasma alanine aminotransferase (ALT) and aspartate aminotransferase concentrations except a significant increase in plasma ALT levels by 2.5% NO supplementation in male mice at 6 month. Histopathological analysis of livers, however, indicated that BGA did not cause significant liver damage compared with controls. In conclusion, our results suggest that NO and SP are free of MC and the long-term dietary supplementation of up to 5% of the BGA may be consumed without evident toxic side-effects.

The effects of Spirulina on anemia and immune function in senior citizens

Anemia and immunological dysfunction (i.e. immunosenescence) are commonly found in older subjects and nutritional approaches are sought to counteract these phenomena. Spirulina is a filamentous and multicellular bule-green alga capable of reducing inflammation and also manifesting antioxidant effects. We hypothesized that Spirulina may ameliorate anemia and immunosenescence in senior citizens with a history of anemia. We enrolled 40 volunteers of both sexes with an age of 50 years or older who had no history of major chronic diseases. Participants took a Spirulina supplementation for 12 weeks and were administered comprehensive dietary questionnaires to determine their nutritional regimen during the study. Complete cell count (CCC) and indoleamine 2,3-dioxygenase (IDO) enzyme activity, as a sign of immune function, were determined at baseline and weeks 6 and 12 of supplementation. Thirty study participants completed the entire study and the data obtained were analyzed. Over the 12-week study period, there was a steady increase in average values of mean corpuscular hemoglobin in subjects of both sexes. In addition, mean corpuscular volume and mean corpuscular hemoglobin concentration also increased in male participants. Older women appeared to benefit more rapidly from Spirulina supplements. Similarly, the majority of subjects manifested increased IDO activity and white blood cell count at 6 and 12 weeks of Spirulina supplementation. Spirulina may ameliorate anemia and immunosenescence in older subjects. We encourage large human studies to determine whether this safe supplement could prove beneficial in randomized clinical trials.

Hypolipidemic, antioxidant, and antiinflammatory activities of microalgae Spirulina

Spirulina is free-floating filamentous microalgae growing in alkaline water bodies. With its high nutritional value, Spirulina has been consumed as food for centuries in Central Africa. It is now widely used as nutraceutical food supplement worldwide. Recently, great attention and extensive studies have been devoted to evaluate its therapeutic benefits on an array of diseased conditions including hypercholesterolemia, hyperglycerolemia, cardiovascular diseases, inflammatory diseases, cancer, and viral infections. The cardiovascular benefits of Spirulina are primarily resulted from its hypolipidemic, antioxidant, and antiinflammatory activities. Data from preclinical studies with various animal models consistently demonstrate the hypolipidemic activity of Spirulina. Although differences in study design, sample size, and patient conditions resulting in minor inconsistency in response to Spirulina supplementation, the findings from human clinical trials are largely consistent with the hypolipidemic effects of Spirulina observed in the preclinical studies. However, most of the human clinical trials are suffered with limited sample size and some with poor experimental design. The antioxidant and/or antiinflammatory activities of Spirulina were demonstrated in a large number of preclinical studies. However, a limited number of clinical trials have been carried out so far to confirm such activities in human. Currently, our understanding on the underlying mechanisms for Spirulina's activities, especially the hypolipidemic effect, is limited. Spirulina is generally considered safe for human consumption supported by its long history of use as food source and its favorable safety profile in animal studies. However, rare cases of side-effects in human have been reported. Quality control in the growth and process of Spirulina to avoid contamination is mandatory to guarantee the safety of Spirulina products.

Isolation of an antihypertensive peptide from alcalase digest of Spirulina platensis

An angiotensin I-converting enzyme (ACE) inhibitory peptide Ile-Gln-Pro with an IC(50) value of 5.77 +/- 0.09 microM was purified from the alcalase digests of Spirulina platensis by gel filtration chromatography and two steps of reverse-phase high-performance liquid chromatography (RP-HPLC). The peptide was synthesized and showed resistance to in vitro digestion by gastrointestinal proteases. Kinetics studies indicated that the peptide was a noncompetitive inhibitor and that the K(i) value was 7.61 +/- 0.16 microM. Oral administration of Ile-Gln-Pro at a dosage of 10 mg/kg showed significant decreases of the weighted systolic blood pressure (SBP) and diastolic blood pressure (DBP) in spontaneously hypertensive rats (SHR) at 4, 6, and 8 h after treatment. The results showed that the ACE inhibitory peptide from Spirulina platensis may have potential for use in the prevention and treatment of hypertension.

Hypocholesterolemic effect of Nostoc commune var. sphaeroides Kützing, an edible blue-green alga

BACKGROUND

Intake of an edible blue-green alga Nostoc commune var. sphaeroides Kützing (N. Commune) has been shown to lower plasma total cholesterol concentration, but the mechanisms behind the hypocholesterolemic effect have not been elucidated.

AIM OF THE STUDY

To elucidate the mechanisms underlying the cholesterol-lowering effect of N. commune in mice.

METHODS

Male C57BL/6J mice were fed the AIN-93 M diet supplemented with 0 or 5% (wt/wt) dried N. Commune for 4 weeks. Lipid levels in the plasma and liver, intestinal cholesterol absorption and fecal sterol excretion were measured. Expression of hepatic and intestinal genes involved in cholesterol metabolism was evaluated by quantitative realtime PCR.

RESULTS

N. commune supplementation significantly reduced total plasma cholesterol and triglyceride concentrations by approximately 20% compared to controls. Intestinal cholesterol absorption was significantly decreased, while fecal neutral sterol output was significantly increased in N. commune-fed mice. mRNA levels of the cholesterol transporters such as Niemann Pick C1 Like 1, scavenger receptor class B type 1, ATP-binding cassette transporters G5 and A1 in small intestine were not significantly different between two groups. Hepatic lipid contents including total cholesterol, triglyceride and free cholesterol in N. commune-fed mice were not significantly altered. However, the expression of cholesterol modulating genes including sterol regulatory element binding protein-2 and 3-hydroxy-3-methylglutaryl coenzyme A reductase were significantly increased in mice fed N. commune.

CONCLUSIONS

N. commune supplementation exerted a hypocholesterolemic effect in mice, largely in part, by reducing intestinal cholesterol absorption and promoting fecal neutral sterol excretion.

A randomized study to establish the effects of spirulina in type 2 diabetes mellitus patients

Spirulina is a microscopic and filamentous cyanobacterium that contains essential amino acids, essential fatty acids, vitamins, minerals and anti-oxidative components. The purpose of this study was to examine effects of spirulina intervention in Korean patients with type 2 diabetes. The subjects were 37 type 2 diabetic patients who visited a diabetic clinic in Seoul and randomly assigned into spirulina (8 g/day) or control group. During the intervention period of 12 weeks, subjects were asked to keep usual diet and prohibited to take any functional foods or dietary supplements. Spirulina supplementation for 12 weeks did not affect anthropometric parameters, however, lowered plasma triglycerides level significantly (p<0.05). Spirulina supplementation also resulted in a significant reduction in plasma malondialdehyde level (p<0.05) and an increase in plasma adiponectin level (p<0.1). The lipid lowering effect of spirulina supplementation was different according to serum lipid levels of the subjects before entering the intervention. The subjects with higher initial triglyceride level showed higher reduction in plasma triglyceride and blood pressure. The subjects with higher initial total cholesterol and LDL-cholesterol level showed higher reduction in plasma concentrations of total cholesterol, LDL-cholesterol, IL-6, and blood pressure. It seems that spirulina supplementation is more effective in subjects with dyslipidemia. This study provides the evidence for beneficial effects of spirulina supplementation on blood lipid profiles, inflammatory variables, and antioxidant capacity in Korean patients with type 2 diabetes. The results suggest that spirulina is a promising agent as a functional food for diabetes management.

Interleukin-10 to tumor necrosis factor-alpha ratio is a predictive biomarker in nonalcoholic fatty liver disease: interleukin-10 to tumor necrosis factor-alpha ratio in steatohepatitis

OBJECTIVES

Fatty liver disease is commonly associated with diabetes mellitus (DM). Insulin resistance (IR) as an investigative biomarker is only concerned with fatty liver that results from DM type 2 associated with metabolic syndrome. Irrespective of IR, DM is generally characterized by overproduction of the proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha), whereas action of the latter is modulated by the anti-inflammatory cytokine interleukin-10 (IL-10). The aim of this study was to investigate the efficacy of using TNF-alpha alone or IL-10/TNF-alpha ratio compared to IR, as a promising biomarker for fatty liver assessment in DM. Furthermore, we hypothesized that using garlic as an immunomodulator may decrease TNF-alpha and increase IL-10 production to improve steatohepatitis.

METHODS

DM was induced metabolically by a high-fat diet to bring about IR, or chemically by alloxan, producing insulin deficiency, in male albino rats. Garlic powder was supplemented (15 mg/kg per day) for 3 weeks. Fatty liver was depicted histologically and biochemically (aspartic aminotransferase, alanine aminotransferase, HOMA-IR, TNF-alpha, IL-10, IL-10/TNF-alpha ratio).

RESULTS

We found that, in contrast to obese rats, garlic decreased IL-10/TNF-alpha ratio, despite decreasing TNF-alpha in alloxan diabetic rats in agreement with the histology, which revealed more prominent improvement in the obese group. Moreover, the effect of garlic was not linked to improvement of IR in obese rats.

CONCLUSION

We conclude that IL-10/TNF-alpha ratio may be considered as a convenient biomarker for investigation of fatty liver of different grades, apart from being associated with IR, and immunomodulation of this ratio in favor of increasing it may exert significant improvement.

Effect of Shilianhua extract and its fractions on body weight of obese mice

Five commercial botanical products (Shilianhua [SLH] tablets, Shiu Huo pills, Fenulyn, Bitter Melon, and Glucose Metabolic Support), available in the US market, with reported claims for regulation of metabolism were screened for their effect on body weight gain in high-fat diet-induced obese mice. Pilot results suggested that SLH tablets attenuated body weight gain, whereas Shiu Huo pills and Fenulyn tended to promote weight gain in the mice on the high-fat diet. To investigate the bioactive components in the SLH tablet, the wild SLH plant (Sinocrassula indica Berge) was collected from China and used to make a variety of extracts including aqueous extract, ethanol extract (SLH-E), and subfraction F100. In the study of metabolic activities, the extracts were administrated through food intake by incorporating them into the diet. A rigorous evaluation of the extracts on body weight was conducted in 2 animal models. The aqueous extract and SLH-E were tested in dietary obese mice, while F100 together with SLH-E was tested in KK-Ay mice, a genetic diabetic model. In the 12- to 16-week study, body weight was not significantly altered by the SLH extracts in the 2 animal models. The results suggest that neither the total extract nor the purified components from the SLH plant have a clear effect in the regulation of body weight. The weight reduction observed with the over-the-counter SLH tablet in the pilot studies may be secondary to other components in the tablet, but not from the SLH extract.

Preventive effects of Spirulina platensis on skeletal muscle damage under exercise-induced oxidative stress

The effects of spirulina supplementation on preventing skeletal muscle damage on untrained human beings were examined. Sixteen students volunteered to take Spirulina platensis in addition to their normal diet for 3-weeks. Blood samples were taken after finishing the Bruce incremental treadmill exercise before and after treatment. The results showed that plasma concentrations of malondialdehyde (MDA) were significantly decreased after supplementation with spirulina (P < 0.05). The activity of blood superoxide dismutase (SOD) was significantly raised after supplementation with spirulina or soy protein (P < 0.05). Both of the blood glutathione peroxidaes (GPx) and lactate dehydrogenase (LDH) levels were significantly different between spirulina and soy protein supplementation by an ANCOVA analysis (P < 0.05). In addition, the lactate (LA) concentration was higher and the time to exhaustion (TE) was significantly extended in the spirulina trail (P < 0.05). These results suggest that ingestion of S. platensis showed preventive effect of the skeletal muscle damage and that probably led to postponement of the time of exhaustion during the all-out exercise.

Dietary supplementation with blueberries, spinach, or spirulina reduces ischemic brain damage

Free radicals are involved in neurodegenerative disorders, such as ischemia and aging. We have previously demonstrated that treatment with diets enriched with blueberry, spinach, or spirulina have been shown to reduce neurodegenerative changes in aged animals. The purpose of this study was to determine if these diets have neuroprotective effects in focal ischemic brain. Adult male Sprague-Dawley rats were fed with equal amounts of diets (blueberry, spinach, and spirulina) or with control diet. After 4 weeks of feeding, all animals were anesthetized with chloral hydrate. The right middle cerebral artery was ligated with a 10-O suture for 60 min. The ligature was later removed to allow reperfusional injury. Animals were sacrificed and brains were removed for caspase-3 enzymatic assays and triphenyltetrazolium chloride staining at 8 and 48 h after the onset of reperfusion. A subgroup of animals was used for locomotor behavior and biochemical assays. We found that animals which received blueberry, spinach, or spirulina enriched diets had a significant reduction in the volume of infarction in the cerebral cortex and an increase in post-stroke locomotor activity. There was no difference in blood biochemistry, blood CO2, and electrolyte levels among all groups, suggesting that the protection was not indirectly mediated through the changes in physiological functions. Animals treated with blueberry, spinach, or spirulina had significantly lower caspase-3 activity in the ischemic hemisphere. In conclusion, our data suggest that chronic treatment with blueberry, spinach, or spirulina reduces ischemia/reperfusion-induced apoptosis and cerebral infarction.

Influência da ingestão de espirulina sobre o metabolismo de ratos exercitados

No presente estudo foram comparadas as respostas metabólicas agudas ao exercício em ratos alimentados com dieta padrão e à base de espirulina. Ratos Wistar jovens foram divididos em dois grupos de acordo com a dieta: controle (C) (dieta padrão) e espirulina (S) (dieta à base de espirulina). Ao final do período experimental (cinco semanas) os animais foram submetidos a uma sessão aguda de exercício de natação (20 minutos, suportando sobrecarga equivalente a 5% do peso corporal) para avaliação do lactato sanguíneo, glicose, insulina, proteínas, albumina e ácidos graxos livres (AGL) séricos. Amostras do músculo gastrocnêmio e fígado foram utilizadas para determinação dos teores de glicogênio e lipídeos. Ambos os grupos C e S apresentaram aumento da glicemia e dos AGL, queda da insulinemia e redução dos teores de glicogênio muscular e hepático pós-exercício. A lactacidemia durante o exercício foi superior no grupo S em relação ao C. Conclui-se que o padrão de respostas ao exercício agudo dos grupos C e S foi semelhante. Contudo, a proteína da dieta pareceu influenciar aspectos do metabolismo glicídico.

Anticlastogenic effect of Spirulina maxima extract on the micronuclei induced by maleic hydrazide in Tradescantia

The aim of this investigation was to determine if extracts of Spirulina maxima reduce the genotoxic damage induced by maleic hydrazide (MH) using the Tradescantia biosssay. Two types of extracts from the alga were prepared: an aqueous extract with two different concentrations, 100 and 500 mg/ml, and a second one, the extract of a 1% solution of dimethyl sulfoxide (DMSO) which corresponded to 100 mg/ml of the alga. The capacity of MH to induce micronuclei (MN) was initially established by administering 0.005, 0.01, and 0.015 mg/ml of the chemical to the Tradescantia inflorescences, and observing its effect after 24 h.The results of this experiment showed a significant MN increase with the two high concentrations tested, although no dose-response effect was observed. For the anticlastogenic assay, the extracts of Spirulina were applied to the inflorescences alone or immediately before the application of MH (0.01 mg/ml) and the induced MN were observed 24 h later. We found that none of the extracts increased the MN level with respect to the untreated plants; also, that MH more or less doubled the basal micronuclei frequency, and finally, that all tested extracts reduced the genotoxic damage caused by MH. The inhibitory indices obtained for the aqueous extracts (100 and 500 mg/ml) and for the DMSO extract were respectively 59, 85, and 56.3%. These data indicate that Spirulina is an anticlastogenic agent and suggest that it is advisable to extend studies on this matter using other biological models.

Arthrospira maxima prevents the acute fatty liver induced by the administration of simvastatin, ethanol and a hypercholesterolemic diet to mice

An evident fatty liver, corroborated morphologically and chemically, was produced in CD-1 mice after five daily doses of simvastatin 75 mg/Kg body weight, a hypercholesterolemic diet and 20 percent ethanol in the drinking water. After treating the animals, they presented serum triacylglycerols levels five times higher than the control mice, total lipids, cholesterol and triacylglycerols in the liver were 2, 2 and 1.5 times higher, respectively, than in control animals. When Arthrospira maxima was given with diet two weeks prior the onset of fatty liver induction, there was a decrement of liver total lipids (40%), liver triacylglycerols (50%) and serum triacylglycerols (50%) compared to the animals with the same treatment but without Arthrospira maxima. In addition to the mentioned protective effect, the administration of this algae, produced a significant increase (45%) in serum high density lipoproteins. The mechanism for this protective effect was not established in these experiments.