Antihyperglycemic and antihyperlipidemic activities of Nannochloropsis oculata microalgae in Streptozotocin-induced diabetic rats.

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.

Effects of Spirulina platensis microalgae on antioxidant and anti-inflammatory factors in diabetic rats.

OBJECTIVES: Lipid peroxidation and hyperglycemia are common signs for diabetes. Natural antioxidants such as Spirulina platensis microalgae (SPM) may prevent lipid peroxidation and hyperglycemia. This study aimed to evaluate the effects of SPM on antioxidant and anti-inflammatory in diabetic rats. MATERIALS AND METHODS: Sixty-four rats were divided into eight groups (n=8) and orally treated with 0, 10, 20 and 30 mg/kg body weight of SPM extract. Experimental groups included diabetic rats fed with 0 (DC), 10, 20 and 30 mg/kg SPM. Healthy rats were treated with 0 mg/kg SPM (HC), 10 mg/kg SPM, 20 mg/kg SPM and 30 mg/kg SPM. At the end of the trial, blood samples were collected and the plasma concentrations of trace minerals (TMs), biochemical parameters, and antioxidant enzymes in liver were evaluated. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), TNF-α (tumor necrosis factor-alpha) and IL-6 (interleukin-6) were evaluated. RESULTS: Our findings showed that diabetes significantly lowered the plasma concentration of TMs and antioxidant enzymes in liver and also increased the levels of malondialdehyde, glucose, lipid profile, AST, ALT, TNF-α and IL-6 (DC vs HC). However, an oral supplement of SPM (20 and 30 mg/kg body weight) lowered levels of malondialdehyde level, glucose, lipid parameters, AST, ALT, TNF-α and IL-6. The same levels increased the plasma contents of zinc, iron, copper and selenium and activity of antioxidant enzymes (P<0.05). CONCLUSION: It can be concluded that diabetes decreases TM concentration and antioxidant enzymes and also increases lipid profile, glucose, AST, ALT, TNF-α and IL-6 concentrations. Inclusion of SPM supplementing (20 and 30 mg/kg body weight) increased some TMs and antioxidant enzymes. SPM may provide TMs for synthesis of antioxidant enzymes which subsequently reduce lipid profile, glucose concentration and anti-inflammatory responses.