Abstract
Background
It is well documented that biologically active components of microalgae can be utilized for treatment of different diseases. This study was conducted to evaluate the antihyperglycemic and antihyperlipidemic activities and weight control of Nannochloropsis oculata microalgae (NOM) in Streptozotocin-induced diabetic male rats.
Methods
Diabetes was induced by intraperitoneal administration of Streptozotocin (55 mg/kg). Healthy and diabetic rats were divided in to six groups. Healthy and diabetic rats orally received distilled water or NOM (10 and 20 mg/kg) for three weeks.
Results
Oral administration of NOM to diabetic rats significantly reduced the serum concentrations of glucose, cholesterol, triglycerides, LDL and increased the serum concentration of insulin and HDL-C (P<0.05). Treatment with NOM had no significant effect on blood parameters in healthy rats (P>0.05). Also, NOM maintained body weight in diabetic rats (P<0.05).
Conclusion
It can be concluded that NOM has antihyperglycemic and antihyperlipidemic activities in diabetic rats.
Introduction
Diabetes is one of most common cause of death in the world, that is mainly caused by persistent hyperglycemia due to disturbance in insulin secretion (type 1 diabetes – T1DM and insulin activity (type 2 diabetes- T2DM) [1, 2]. Reactive oxygen species (ROS) are produced in diabetes mellitus [3]. Today researchers are trying to find natural products such as herbs and algae which can be used to normalize the blood glucose and dyslipidemia in diabetes mellitus. Natural antioxidants in microalgae structure have been extensively considered for treatment of diabetes because they decrease the risk of chronic diseases and promote human health [4, 5]. Microalgae are tiny photosynthetic components that convert solar energy to biomass. It is well known that algae products especially cyanobacteria have therapeutic properties [6, 7]. Therapeutic potential of microalgae may be associated to biological compounds such as essential amino acids, vitamins, pigments, and lipid profile [8]. Nannochloropsis oculata, marine unicellular microalgae, is a member of the Eustigmatophyceae class and are known to have nutritional values [9, 10, 11]. Nannochloropsis microalgae (NOM) contain some components including soluble and insoluble polysaccharide, protein and eicosapentaenoic acid [12, 13]. Studies have also shown that eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) regulate levels of blood lipids [18, 19, 20]. In addition, NOM protects the activity of EPA and DHA [14, 15] due to its antioxidant pigments and polyunsaturated fatty acids [13, 16]. On the other hand, previous studies have shown that the EPA in NOM compound can efficiently be used into the blood, liver, and brain lipids of rats [21, 22]. Thus, NOM prevent EPA and DHA oxidation by their antioxidant properties. Werman et al. [17] reported that male rats fed with Nannochloropsis oculata showed lower level of cholesterol in comparison to control group. NOM also contains insoluble fibers that decrease plasma cholesterol by modification of bile acid absorption and metabolism [23]. Moreover, Pandey et al. [24] reported that treatment with other microalgae (Spirulina maxima) decreased the serum concentration of glucose in diabetic rats. The S. platensis microalga interacts with ROS and quenches them during oxidative process [25, 26]. Since the most studies have used Streptozotocin (STZ) in order to induce diabetes [8, 24, 27], as we have used in this study. Therefore, this study aimed to evaluate the antihyperglycemic or antihyperlipidemic activities of NOM in healthy and diabetic rats.
Methods
Experimental animals
The current study was conducted in Birjand University (South Khorasan-Iran). Male Wistar rats (n=60, 200 ± 20 g) were kept at room temperature (25°C). A lighting diet (12h light/12h dark) was considered. All the rats fed a standard pellet diet (Javeneh Khorasan Company) and water ad libitum. The rats were separated into two groups (healthy and diabetic) and treated with microalgae (10 and 20 mg/kg BW, orally for three weeks). A control group received distilled water. Thus rats were divided into 6 groups with 10 animals per group. Experimental treatments are presented in Table 1. The Nannochloropsis oculata microalga was purchased from Ghazaye Sabze Khalij (Bandar Abbas-Iran). Weight was recorded weekly in order to evaluate the weight changes. All the experiments were approved by the Animal Ethics Committee of Birjand University (Ethics Code: BU/94-D-12661). The experiments were conducted in accordance with the National Institutes of Health Guide for the Care and Use of Laboratory Animals.
Experimental groups (BW= body weight).
| Healthy | Diabetic |
|---|---|
| Control (0.3 ml of distilled water) | Control (0.3 ml of distilled water) |
| Microalgae 10 mg.kg-1 BW | Microalgae 10 mg.kg-1 BW |
| Microalgae 20 mg.kg-1 BW | Microalgae 20 mg.kg-1 BW |
Ethical approval: The research related to animals use has been complied with all the relevant national regulations and institutional policies for the care and was approved by Birjand University Research Ethical Committee (Ethics Code: BU/94-D-12661), Birjand University, Birjand, Iran, on the use of animals, and conformed to the Guide for the Care and Use of Laboratory Animals published by the U. S. National Institutes of Health (NIH Publication No. 85–23, revised 1996) for studies involving experimental animals.
Induction of experimental diabetes
Streptozotocin (Sigma-Aldrich) was dissolved in citrate buffer, pH 4.5 (0.1 mol/l trisodium citrate, 0.1 mol/l citric acid) and used to induce diabetes mellitus (55 mg/kg BW) in rats [27]. Diabetes was confirmed by measuring of blood glucose levels three days after the STZ injection. Animals with serum glucose level higher than 250 mg/dl were considered as diabetic [27].
Biochemical analysis
On 21 d of trial and after a 12-h fasting, animals were anesthetized then decapitated and 3 ml blood of per rat were collected and centrifuged at 3000×g for 15min in order to obtain the sera. Blood samples were analyzed to determine the levels of glucose, insulin, albumin, cholesterol, HDL-C, LDL-C, total protein, total bilirubin, triglycerides, creatinine, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and uric acid by auto-analyzer apparatus (Gesun Chem 200. Italy).
Statistical analysis
The analysis was performed using the statistical software package Graph Pad Prism version 5.0 for Windows (Graph Pad Software, San Diego, CA). The data was analyzed using one-way analysis of variance (ANOVA) followed by Dunnett’s Multiple Range Test. Animals in healthy group and diabetic group were separately compared by ANOVA way. Healthy and diabetic rats were also compared by dose by T-test. The results show the mean ± standard deviation, with a P value of <0.05 being considered statistically significant.
Results
Our findings show that the serum concentrations of glucose, insulin, triglycerides, cholesterol, LDL-C and HDL-C were not influenced by NOM administration in healthy rats (Tables 3 and 4; P>0.05). Administration of NOM in diabetic rats significantly decreased the serum concentration of glucose, triglycerides, cholesterol, and LDL-C in comparison to diabetic control rats. As demonstrated in Tables 2 and 3, HDL and insulin levels remarkably decreased in STZ diabetes in comparison to healthy control. Administration of NOM (20 mg/kg) in diabetic rats effectively prevented HDL and decreased insulin. Significant differences were seen between diabetic rats and healthy rats for total protein, albumin, alkaline phosphatase, aspartate amino transferase and alanine amino transferase (P<0.05; Tables 4 and 5). Oral administration of NOM had no significant effects on the mentioned parameters in diabetic rats (Tables 4 and 5). There were no significant differences between diabetic rats and healthy rats for total bilirubin, uric acid and creatinine (P>0.05). Results indicated that diabetic rats had lower final weight compared with healthy rats
Effect of Nannochloropsis oculata microalgae (NOM) at levels of 10 and 20 mg.kg-1 of body weight on the serum concentrations of glucose and insulin in healthy and diabetic rats.
| Glucose (mg/dl) | Insulin (mIU/ml) | |||||
|---|---|---|---|---|---|---|
| Groups | Healthy | Diabetic | P | Healthy | Diabetic | P |
| Control | 180±11B | 380±21A,a | * | 1.12±0.26A | 0.32±0.06B,c | * |
| NOM 10 | 175±19B | 250±24A,b | * | 1.1±0.3A | 0.6±0.11B,b | * |
| NOM 20 | 173±19 | 180±18c | NS | 1.13±0.14 | 1.0±0.25a | NS |
| P | NS | * | NS | * | ||
A-B shows significant differences at per row at P<0.05 and a-c shows significant differences in per column at level of 0.05*. NS: nonsignificant.
Column comparisons were performed by ANOVA and row comparisons were done with T-test.
Effects of Nannochloropsis oculata microalgae (NOM) at rates of 10 and 20mg.kg-1 of body weight on the serum concentrations of triglycerides, cholesterol or LDL-C and HDL-C in healthy and diabetic rats.
| Triglycerides (mg/dl) | Cholesterol (mg/dl) | LDL-C (mg/dl) | HDL-C (mg/dl) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Groups | Healthy | Diabetic | P | Healthy | Diabetic | P | Healthy | Diabetic | P | Healthy | Diabetic | P |
| Control | 32±5B | 63±4A,a | * | 51±4B | 80±7A,a | * | 32±4B | 70±8A,a | * | 36±5A | 19±3B,b | * |
| NOM 10 | 34±7B | 60±6 A,a | * | 53±10 | 61±9b | NS | 34±5B | 55±7A,b | * | 31±5A | 21±5B,b | * |
| NOM 20 | 36±4 | 42±10b | NS | 54±9 | 60±9b | NS | 36±6 | 41±4c | NS | 32±4 | 26±9a | NS |
| P | NS | * | NS | * | NS | * | NS | * | ||||
A-B shows significant differences at per row at P<0.05 and a-b shows significant differences in per column at level of 0.05*. NS: non-significant.
Column comparisons were performed by ANOVA and row comparisons were done with T-test.
Effects of Nannochloropsis oculata microalgae (NOM) at rates of 10 and 20mg.kg-1 of body weight on the serum concentrations of total protein, albumin, uric acid and creatinine in healthy and diabetic rats.
| Total protein (g/dl) | Albumin (g/dl) | Uric acid (mg/dl) | Creatinine (mg/dl) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Groups | Healthy | Diabetic | P | Healthy | Diabetic | P | Healthy | Diabetic | P | Healthy | Diabetic | P | |
| Control | 3.5±0.5B | 5.2±0.6A | * | 3.1±0.4B | 4.5±0.6A | * | 2.1±0.4 | 2.3±0.4 | NS | 0.5±0.05 | 0.5±0.07 | NS | |
| NOM 10 | 3.3±0.4B | 5.5±0.5 A | * | 2.9±0.5B | 4.7±0.5A | * | 1.9±0.5B | 2.2±0.2 | NS | 0.6±0.1 | 0.6±0.1 | NS | |
| NOM 20 | 3.6±0.5B | 5.0±0.6A | * | 2.8±0.3B | 5.0±0.5A | * | 2.2±0.8 | 2.4±0.2 | NS | 0.7±0.2 | 0.7±0.1 | NS | |
| P | NS | NS | NS | NS | NS | NS | NS | NS | |||||
A-B shows significant differences at per row at P<0.05 *. NS: non-significant. Column comparisons were performed by ANOVA and row comparisons were done with T-test.
Effects of Nannochloropsis oculata microalgae (NOM) at rates of 10 and 20mg.kg-1 of body weight on the serum concentrations of total bilirubin, alkaline phosphatase (ALP), aspartate amino transferase (ASAT) and alanine amino transferase (ALAT) in healthy and diabetic rats.
| Total bilirubin (mg/dl) | ALP (U/l) | ASAT (U/l) | ALAT (U/l)) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Groups | Healthy | Diabetic | P | Healthy | Diabetic | P | Healthy | Diabetic | P | Healthy | Diabetic | P |
| Control | 0.17±0.04 | 0.17±0.05 | NS | 86±15B | 431±19A | * | 97±25B | 420±31A | * | 80±5.5 B | 154±6.4 A | * |
| NOM 10 | 0.17±0.05 | 0.18±0.05 | NS | 89±11B | 440±18A | * | 101±14B | 430±65A | * | 75±5.3 B | 156±8.6 A | * |
| NOM 20 | 0.18±0.05 | 0.19±0.04 | NS | 97±17B | 483±85A | * | 113±28B | 442±67A | * | 84±9.1 B | 153±6.0A | * |
| P | NS | NS | NS | NS | NS | NS | NS | NS | ||||
A-B shows significant differences at per row at P<0.05 NS: non-significant. Column comparisons were performed by ANOVA and row comparisons were done with T-test.
(P<0.05). Our findings in Table 6 show that treatment with NOM increased final weight in healthy rats and helped to maintain the weight in diabetic rats (P<0.05).
Effects of Nannochloropsis oculata microalgae (NOM) at rates of 10 and 20mg.kg-1 of body weight on final body weight (g) in healthy and diabetic rats.
| Final Weight (g) | |||
|---|---|---|---|
| Groups | Healthy | Diabetic | P |
| Control | 225±13A,c | 170±13B,b | * |
| NOM 10 | 250±13A,b | 185±11B,a | * |
| NOM 20 | 270±17 A,a | 190±13B, a | * |
| P | * | * | |
A-B shows significant differences at per row at P<0.05 and a-c shows significant differences in per column at level of 0.05*. NS: non-significant. Column comparisons were performed by ANOVA and row comparisons were done with T-test.
Discussion
There were significant differences between healthy and diabetic rats (control and NOM10) for insulin and glucose concentration. It is well known that STZ increases glucose concentration. Our findings were confirmed by other researchers who showed that administration of STZ increased glucose and decreased insulin concentration in rats [21, 23, 28]. Montilla et al. [29] believed that hyperglycemia induced injuries in tissues and brain, urinary glucose excretion and decreased plasma insulin. These injuries create physiologic changes in some tissues, where oxidative stress induced by hyperglycemia plays an important role in the etiology [25, 30, 31]. In this regard, Gu et al. [32] stated that STZ damages pancreatic β-cells by induction of ROS and thus it reduces capability of insulin secretion. ROS play a key role in development and progression of diabetes and levels of ROS were increased in pancreatic islets of diabetic rats [27]. Our results showed that NOM has protective effects on insulin and glucose concentration, but significant differences were not observed between diabetic rats treated with NOM 20 and healthy. Unfortunately, we could not find any study showing effects of NOM on glucose and insulin in healthy and diabetic rats. Other studies showed that treatment of diabetic rats with Spirulina microalgae [28, 29] and Chlorella microalgae [30, 31] reduced glucose levels and increased insulin concentration. It seems NOM reduces glucose levels by insulin secretion from β-cell islet or prevention of pancreatic injuries or increase transport of glucose to peripheral tissues. The idea was supported by Yanardag et al. [33] who showed that treatment with insulin had protective effects against STZ in rats. We believed that antioxidant pigments present in NOM [34], protect cellular damage induced by ROS and may increase insulin secretion in diabetic rats. In the current study, NOM not only contains antioxidant pigments but also contains selenium and possible antioxidant vitamins which may protect pancreas. Selenium modulates the antioxidant system through cooperating in glutathione peroxidases, thioredoxin reductase, and iodothyronine deiodinase structure. Our theory is confirmed by other researchers who showed that S. platensis microalgae interacts with ROS during the oxidative process and quenches free radicals [6, 22]. Glucose and lipid metabolism are associated other. Similar to glucose and insulin findings, administration of STZ increased lipid profile in rats when compared with normal rats (healthy control vs diabetic control), i.e. an increase in the serum concentrations of triglycerides, cholesterol, LDL-C and a decrease in HDL-C.
In present study, diabetic rats showed abnormalities in lipid metabolism as proved by increased the plasma total triglycerides, cholesterol, LDL-C and decreased HDL-C levels. Treatment with NOM, for three weeks, markedly reduced plasma TG, total cholesterol, and LDL-C associated with significant increased HDL-C levels in diabetic rats indicating its potent antihyperlipidemic and anti-atherogenic activity. Insulin suppresses the release of free fatty acids by inhibition the activity of hormone sensitive lipases and subsequently inhibits lipolysis. Since the activity of this enzyme is to be increased in diabetes, more fatty acid releases to the circulation by lipolysis, therefore more β-oxidation of FA which produces more acetyl-CoA and cholesterol in diabetics. The hypoinsulinemia in diabetes plays an important role in disturbance of lipid profile. This study indicated that NOM supplementation improved lipid profile in diabetic rats. The hypocholesterolaemic activity of NOM may be due to the prevention of absorption of cholesterol from the intestines (similar to Spirulina) [10, 35, 36, 37, 38] or inhibition of oxidation and the uptake of LDL-C. There are reports documenting an improvement in lipid profile and oxidative status in diabetic animals and humans treated with other microalgae [28, 39, 40, 41, 42, 43]. Markovits et al. [44] reported that dietary fibers present in Nannochloropsis, especially insoluble fibers, prevent intestinal cholesterol absorption [45] and have anti-hypercholestromic activity. EPA is extensively founds in NOM and has protective effects against atherogenesis and lipid abnormalities [11]. Moreover, EPA and DHA regulate levels of blood lipids [18, 19, 20]. In addition, Mokady and Sukenik [30] reported that EPA and DHA act as lowering lipid and cholesterol in blood, liver, and brain. Some studies showed that hypoinsulinemia caused significant changes in lipids turnover [29, 41] and since NOM increased insulin concentration and an increase in insulin concentration may be factor for improvement in lipid profile in diabetic rats treated with NOM (20 mg/kg). On the other hand, oxygen free radical initiates peroxidation of lipids, which it stimulates glycation of protein and inactivation of enzymes. There are clinical studies that show production of ROS is to be increased in both types of diabetes. Normally, the level of oxidative stress is modulated by antioxidant defense systems [37]. Thus, present antioxidant pigments in NOM may decrease negative effects of ROS on lipid profiles. The oxygen species, as oxidants are known to increase the lipids and glucose. Antioxidant pigments, vitamins and minerals may interact with oxidants and thus decrease their negative effects on lipid parameters.
In the present study STZ increased the serum concentrations of albumin and protein in diabetic rats (P<0.05) without significant changes in uric acid, total bilirubin, and creatinine concentrations (P>0.05). Administration of NOM did not have any effect on albumin and protein in diabetic rats. Although diabetes mellitus disturbs albumin and protein metabolism [43], but Montilla et al. [29] did not observe significant changes in albumin and creatinine in STZ-induced diabetic rats. Partly similar to our observation, Kagan et al. [45, 46] showed EPA-rich polar lipid obtained from NOM had no significant effect on the plasma concentration of albumin, protein, bilirubin and creatinine in male rats.
In our STZ induced hepatotoxicity which is proved by increased levels of ALP, ALT and AST in the serum [47]. Our findings were confirmed by other researchers who showed STZ increases levels of ALP, ALT and AST in serum [44] and kidney [48]. Treatment of rats with NOM had no significant effect on mentioned parameters. Parallel to our findings, Kagan et al. [45] reported that EPA-rich polar lipid oil, produced from NOM, does not change ALP, ALAT and ASAT concentration in male rats.
Diabetic rats (control group) showed lower body weight compared with control healthy rats (P<0.05). Our observations were confirmed by others [23, 31, 49]. It is well known that diabetes is accompanied with some metabolic diseases that increase weight loss [29, 41]. Oral administration of NOM prevented weight loss in diabetic rats. In contrast to our findings, Nuno et al. [26] documented that NOM administration did not change weight in diabetic rats. In agreement with our findings, treatment with other microalgae (Spirulina microalgae; 5-15 mg.kg-1 BW) maintained weight in diabetic rats [50, 51, 52, 53, 54]. NOM may maintain weight by increased insulin and decreased glucose level that alleviate metabolic disorders. In addition, antioxidant pigments and EPA, present in NOM, may maintain levels of glucose, insulin and lipid profile that subsequently improve metabolism in body, resulting in weight maintain. Interestingly, NOM increased weight in healthy rats without affecting on blood biochemical parameters. It is may be related to NOM components that increases body weight and prevents disturb in blood parameters.
Conclusion
In conclusion, STZ decreased body weight and the serum concentration of HDL-C or insulin and also increased other lipid parameters, glucose, ALP, AST and ALT concentrations in diabetic rats when compared with healthy rats, but NOM reduced lipid profile except HDL-C, glucose and it also increased insulin and HDL-C in diabetic rats. Thus, NOM has anti-hyperlipidemic and anti-hyperglycemic activity in diabetic rats. Oral administration of NOM controlled body weight in diabetic rats. These potentials may be explained by some components present in NOM such as fibers, lipid profile and antioxidant pigments. These findings suggest using NOM for treatment of diabetes mellitus. The relation between NOM and diabetes will be needed more studies.
Acknowledgment
This work was supported by Birjand University (South Khorasan-Iran). Their support is thankfully appreciated. In addition, Ms. Fariba Nasirian carried out this work in partial project fulfillment of the requirements to obtain the MS.c degree in Physiology.
Abbreviations
- NOM
Nannochloropsis oculata microalgae
- T2DM
Type 2 Diabetes Mellitus
- AST
Aspartate aminotransferase
- ALT
Alanine aminotransferase
- DHA
Docosahexaenoic acid
- EPA
Eicosapentaenoic acid
- ALP
Alkaline phosphatase
- STZ
Streptozotocin
- BW
Body weight
- HR
Healthy rats
- DR
Diabetic rats
Authors’ contributions: NM & HS designed and supervised the study. FN conducted all experiments, statistical analysis, interpreted the results and wrote a draft of the manuscript while NM & HS critically revised and finalized the manuscript for submission. All authors equally contributed. They read and approved the final manuscript.
Conflict of interest: Authors state no conflict of interest.
References
1 Olokoba AB, Obateru OA, Olokoba LB. Type 2 Diabetes Mellitus: A Review of Current Trends. Oman Med J. 2012;27(4):269-273.10.5001/omj.2012.68Search in Google Scholar PubMed
2 Kahn SE, Cooper ME, Del Prato S. Pathophysiology and treatment of type 2 diabetes: perspectives on the past, present, and future. Lancet. 2014;383(9922):1068-1083.10.1016/S0140-6736(13)62154-6Search in Google Scholar PubMed
3 Maritim, AC, Sanders RA, Watkins JB. Diabetes, oxidative stress and antioxidants. A Review. J Biochem Mol Toxicol. 22003;17;24-38.10.1002/jbt.10058Search in Google Scholar
4 Degirolamo C, Kelley KL, Wilson MD, Rudel LL. Dietary n-3 LCPUFA from fish oil but not alpha-linolenic acid-derived LCPUFA confers atheroprotection in mice. J Lipid Res. 2010;51(7):1897-1905.10.1194/jlr.M005058Search in Google Scholar PubMed
5 Jagtap U, Bapat V. Artocarpus: a review of its traditional uses, phytochemistry and pharmacology. J Ethnopharmacol. 2010;129(2):142-166.10.1016/j.jep.2010.03.031Search in Google Scholar PubMed
6 Belay A. The potential application of Spirulina (Arthrospira) as a nutritional and therapeutic supplement in health management. J Functional Food. 2002;5:1521-4524.Search in Google Scholar
7 Karpov L, Brown II, Poltavtseva NV, Ersova ON, Karakis SG, Vasileve TV. The postradiation use of vitamin-containing complexes and a phycocyanin extract in a radiation lesion in rats. Radiatsionnaia biologiia, radioecologiia/Rossiiskaia akademiia nauk. J Alg Biomass utiliz. 1999;40(3):310-314.Search in Google Scholar
8 Pandey JP, Tiwari A, Mishra G, Mishra RM. Role of Spirulina maxima in the Control of Blood Glucose Levels and Body Weight in Streptozotocin induced Diabetic Male Wistar rats. J Alg Biomass utiliz. 2011;2(4):35- 37.Search in Google Scholar
9 Durmaz, Y. Vitamin E (α-tocopherol) production by the marine microalgae Nannochloropsis oculata (Eustigmatophyceae) in nitrogen limitation. Aquacul. 2007;272(1–4):717-22.10.1016/j.aquaculture.2007.07.213Search in Google Scholar
10 Ratih P, Se-Kwon K. Biological activities and health benefit effects of natural pigments derived from marine algae. J Functional Food. 2011;3:255-266.10.1016/j.jff.2011.07.001Search in Google Scholar
11 Saxena AK, Srivastava P, Kale RK, Baquer NZ. Impaired antioxidant status in diabetic rat liver. Effect of vanadate. Biochem Pharmacol.1993;45:539-542.10.1016/0006-2952(93)90124-FSearch in Google Scholar
12 Samuels R, Mani UV, Iyer UM, Naiak US. Hypocholesterolemic Effect of Spirulina in Patients with Hyperlipidemic Nephrotic Syndrome. J Medic Food. 2002;5(2):91-96.10.1089/109662002760178177Search in Google Scholar
13 Brown MR, Jeffrey SW, Volkman JK, Dunstan GA. Nutritional properties of microalgae for mariculture. Aquaculture. 1997;151: 315-331.10.1016/S0044-8486(96)01501-3Search in Google Scholar
14 Seto A, Kumasaka K, Hosaka M, Kojima E, Kashiwakura M, Kato T. Production of eicosapentaenoic acid by marine microalgae and its commercial utilization for aquaculture. Industrial appl single cell oil. Am Oil Chem Soci Champaign.1992;2:219-234.Search in Google Scholar
15 Sandnes JM, Källqvist T, Wenner D, Gislerød HR. Combined influence of light and temperature on growth rates of Nannochloropsis oceanica: linking cellular responses to large-scale biomass production. J Appl Phycol. 2005;17(6):515-25.10.1007/s10811-005-9002-xSearch in Google Scholar
16 Ramamoorthy A, Premakumari S. Effect of supplementation of Spirulina on hypercholesterolemic patients. J Food Sci Technol. 1996;33:124-128.Search in Google Scholar
17 Werman MJ, Sukenik A, Mokady S. Effects of the marine unicellular alga nannochloropsis sp. to reduce the plasma and liver cholesterol levels in male rats fed on diets with cholesterol. Biosci Biotechnol Biochem. 2003;67(10):2266-2268.10.1271/bbb.67.2266Search in Google Scholar PubMed
18 Sublette ME, Ellis SP, Geant AL, Mann JJ. Meta-analysis of the effects of eicosapentaenoic acid (EPA) in clinical trials in depression. J Clin Psychiatry. 2011;72(12):1577-1584.10.4088/JCP.10m06634Search in Google Scholar PubMed
19 Harris WS. Fish oil and plasma lipid and lipoprotein metabolism in human: a critical review. J Lipid Res. 1989;30:785-807.10.1016/S0022-2275(20)38310-3Search in Google Scholar
20 Herold PM, Kinsella JE. Fish oil consumption and decreased risk of cardiovascular disease: a comparison of findings from animal and human feeding trials. Am J Clin Nutr. 1989;43:566-598.10.1093/ajcn/43.4.566Search in Google Scholar PubMed
21 Kinsella JE, Lokesh B, Stone RA. Dietary n-3 polyunsaturated fatty acids and amelioration of cardiovascular disease: possible mechanisms. Am J Clin Nutr. 1990;52: 1-28.10.1093/ajcn/52.1.1Search in Google Scholar PubMed
22 Sukenik A, Takahashi H, Mokady S. Dietary lipids from marine unicellular algae enhance the amount of liver and blood omega-3 fatty acids in rats. Ann Nutr Metab. 1994;38:85-96.10.1159/000177797Search in Google Scholar PubMed
23 Mokady S, Sukenik A. A marine unicellular alga in diets of pregnant and lactating rats as a source of omega-3 fatty acids for the developing brain of their progeny. J Sci Food Agric. 1995;68:133-139.10.1002/jsfa.2740680202Search in Google Scholar
24 Pandey JP, Tiwari A, Mishra G, Mishra RM. Role of Spirulina maxima in the Control of Blood Glucose Levels and Body Weight in Streptozotocin induced Diabetic Male Wistar rats. J Alg Biomass utiliz. 2011;2(4):35-37.Search in Google Scholar
25 Eastwood MA. The physiological effect of dietary fiber: an update. Ann Rev Nutr. 1992;12:19-35.10.1146/annurev.nu.12.070192.000315Search in Google Scholar PubMed
26 Nuno K, Villarruel-Lopez A, Puebla-Perez AM, Romero-Velarde E, Puebla-Mora AG, Ascencio F. Effects of the marine microalgae Isochrysis galbana and Nannochloropsis oculata in diabetic rats. J Funct Foods. 2013;5:106-115.10.1016/j.jff.2012.08.011Search in Google Scholar
27 Sadri H, Taghi Goodarzi M, Salemi Z, Seifi M. Antioxidant effects of biochanin a in streptozotocin induced diabetic rats. Braz Arch Biol Technol. 2017;60:1-10.10.1590/1678-4324-2017160741Search in Google Scholar
28 Estrada JEP, Bescós PB, Fresno AMV. Antioxidant activity of different fractions of Spirulina platensis protean extract. Il Farmaco. 2001;56:497-500.10.1016/S0014-827X(01)01084-9Search in Google Scholar
29 Montilla PP, Barcos M, Munoz MC, Bujalance I, Tunez I. Red wine prevents brain oxidative stress and nephropathy in streptozotocin-induced diabetic rats. J Biochem Molecul Biol. 2005;5:539-544.10.5483/BMBRep.2005.38.5.539Search in Google Scholar PubMed
30 Mokady S, Sukenik A. A marine unicellular alga in diets of pregnant and lactating rats as a source of v3 fatty acids for the developing brain of their progeny. J Sci Food Agric. 1995;68:133-139.10.1002/jsfa.2740680202Search in Google Scholar
31 Baynes JW, Thorpe SR. The role of oxidative stress in diabetic complications. Curr Opinion Endocrinol. 1996;3:277-284.10.1097/00060793-199608000-00001Search in Google Scholar
32 Gu D, Arnush M, Sarvetnic N. Endocrine/exocrine intermediate cells in Streptozotocin treated Ins-IFN-gamma transgenic mice. Pancreas. 1997;15(3):246-50.10.1097/00006676-199710000-00005Search in Google Scholar PubMed
33 Yanardag R, Simmon L, Wolf A. Hypoglycemic activity of insulin in STZ induced diabetic rats. 1999. http://www.diabetes.org/diabetesstatistics.>Search in Google Scholar
34 Ihara Y, Toyokuni S, Uchida K, Odaka H, Tanaka T, Ikeda H, Hiai H, Seino Y, Yamada Y. Hyperglycemia causes oxidative stress in pancreatic beta- cells of GK rats a model of type 2 diabetes. Diabetes. 1999;48:927-932.10.2337/diabetes.48.4.927Search in Google Scholar PubMed
35 Anitha L, Chandralekha K. Effect of Supplementation of Spirulina on Blood Glucose, Glycosylated Hemoglobin and Lipid Profile of Male Non- Insulin Dependent Diabetics. Asi J Exp Biol Sci. 2016;136-46.Search in Google Scholar
36 Hotta N, KOH, N, Sakakibara F, Nakaruma J, Hamada Y, Hara T. Effect of beraprost sodium and insulin on the electroretinogram, nerve conduction and blood flow in rats with streptozotocin induced diabetes. Diabetes. 1996;4(3):361-366.10.2337/diab.45.3.361Search in Google Scholar PubMed
37 Amin A, Lotfy M, Mahmoud-Ghoneim D, Adeghate E A, Al-Akhras M, Al-Saadi M, et al. Pancreas-protective effects of chlorella in STZ-induced diabetic animal model: insights into the mechanism. J Diabetes Mellitus. 2011;1(3):36-45.10.4236/jdm.2011.13006Search in Google Scholar
38 Kafaie S, Loh SP, Mohtarrudin N. Acute and sub-chronic toxicological assessment of Nannochloropsis oculata in rats. Afr J Agric Res. 2012;7(7):1220-1225.10.5897/AJAR11.1793Search in Google Scholar
39 Kent M, Welladsen HM, Mangott A, Li Y. Nutritional evaluation of Australian microalgae as potential human health supplements. Plos One. 2015;10(2):e0118985.10.1371/journal.pone.0118985Search in Google Scholar PubMed
40 Nagarchi K, Ahmed S, Sabus A, Saheb SH. Effect of Streptozotocin on Glucose levels in Albino Wister Rats. J Pharm Sci Res. 2015;7(2):67-69.Search in Google Scholar
41 Mani UV, Desai S, Iyer U. Studies on the longterm effect of Spirulina supplementation on serum lipid profile and glycated proteins in NIDDM patients. J Nutraceutic Function Medic Food. 2000;2:25-32.10.1300/J133v02n03_03Search in Google Scholar
42 Saxena AK, Srivastava P, Kale RK, Baquer NZ. Impaired antioxidant status in diabetic rat liver. Effect of vanadate. Biochem Pharmacol. 1993;45:539-542.10.1016/0006-2952(93)90124-FSearch in Google Scholar PubMed
43 Seto A, Kumasaka K, Hosaka M, Kojima E, Kashiwakura M, Kato T. Production of eicosapentaenoic acid by marine microalgae and its commercial utilization for aquaculture. Industrial appl single cell oil. Am Oil Chem Soci Champaign. 1992;2:219-234.10.1201/9781439821855.ch12Search in Google Scholar
44 Markovits A, Conejeros R, Lopez L, Lutz M. Evaluation of marine microalga Nannochloropsis sp. as a potential dietary supplement. Chemical, nutritional, and short term toxicological evaluation in rats. Nutr Res. 1992;12:1273-1284.10.1016/S0271-5317(05)80784-5Search in Google Scholar
45 Kagan ML, Sullivan DW, Gad SC, Ballou CM. Safety assessment of EPA-rich polar lipid oil produced from the microalgae Nannochloropsis oculata. Int J Toxicol. 2014;33(6):459-74.10.1177/1091581814553453Search in Google Scholar PubMed
46 Kagan ML, Sullivan, DW, Gad SC, Ballou CM. Spirulina attenuates cyclosporine-induced nephrotoxicity in rats. J Appl Toxicol. 2006;26:444-451.10.1002/jat.1159Search in Google Scholar PubMed
47 Eastwood MA. The physiological effect of dietary fiber: an update. Ann Rev Nutr. 1992;12:19-35.10.1146/annurev.nu.12.070192.000315Search in Google Scholar
48 Maged MY, Rahiem A, Nehad ER. Alterations in body weight, protein profile, nonprotein nitrogen constituents and kidney structure in diabetic rats under glibenclamide treatment. J Islam Univers Gaza. 2004;12(1):37-54.Search in Google Scholar
49 Estrada JEP, Bescós PB, Fresno AMV. Antioxidant activity of different fractions of Spirulina platensis protean extract. Il Farmaco. 2001;56:497-500.10.1016/S0014-827X(01)01084-9Search in Google Scholar
50 Betteridge DJ. Diabetes, lipoprotein metabolism and atherosclerosis. Br Med Bull. 2004;45:285-311.10.1093/oxfordjournals.bmb.a072317Search in Google Scholar PubMed
51 Sublette ME, Ellis SP, Geant AL, Mann JJ. Meta-analysis of the effects of eicosapentaenoic acid (EPA) in clinical trials in depression. J Clin Psychiatry. 2011;72(12):1577-1584.10.4088/JCP.10m06634Search in Google Scholar PubMed PubMed Central
52 Nasirian F, Dadkhah M, Moradi-kor N, Obeidavi Z. Effects of Spirulina platensis microalgae on antioxidant and anti-inflammatory factors in diabetic rats. Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy. 2018;11:375-380.10.2147/DMSO.S172104Search in Google Scholar PubMed PubMed Central
53 Mesbahzadeh B, Rajaei SA, Tarahomi P, et al. Beneficial effects of Spirogyra Neglecta Extract on antioxidant and anti-inflammatory factors in streptozotocin-induced diabetic rats. BioMol Concepts. 2018;9:184-189.10.1515/bmc-2018-0015Search in Google Scholar PubMed
54 Nasirian F, Mesbahzadeh B, Maleki SA, Mogharnasi M, Kor NM. The effects of oral supplementation of spirulina platensis microalgae on hematological parameters in streptozotocin-induced diabetic rats. Am J Transl Res. 2017;9(12):5238-5244.Search in Google Scholar PubMed
© 2019 Fariba Nasirian, Hadi Sarir, Nasroallah Moradi-kor, published by De Gruyter
This work is licensed under the Creative Commons Attribution 4.0 Public License.
