Sulphated galactopyran derived fromGracilaria opuntia, a marine macroalgae restores the antioxidant metabolic enzymes during STZ induced diabetic rats

Objective:To screen the effect of sulphated galactopyran fraction isolated from Gracilaria opuntia (G. opuntia) (FM4) in streptozotocin (STZ) induced diabetic rats. Methods:In vitro antioxidant assays of FM4 were estimated byDPPH,ABTS, hydroxyl free radical and Nitric oxide free radical activities.FM4 was purified and characterized by1H-NMR spectra andFTIR as sulphated galactopyran. Diabetes was induced intraperitonially by single dose ofSTZ (55 mg/kg body weight).FM4 was administrated orally (80, 100, 125 mg/kgBW) to diabetic rats for 60 days. The enzymatic and non-enzymatic antioxidants such as superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione-S-transferase (GST), lipid peroxidase (LPx), glutathione reduced (GSH), vitamin-C (VIT-C) and vitamin-E (VIT-E) levels were estimated. Glibenclamide was used as standard drug. Results:Our results demonstrated that the aqueous extract ofG. opuntia possess free radical scavenging activity. During FM4 fraction treatment (100 mg/kgBW), theSOD,GPx,CAT,GST, GSH,VIT-C and VIT-E levels were significantly (P < 0.05) increased, and theLPx levels were decreased in different organs such as liver, kidney, brain and pancreas of diabetic rats. Conclusions: The sulphated galactopyran fraction of the marine macroalgae (G. opuntia) possesses the antioxidant activity which might help in the prevention of oxidative damage that occurs during diabetes.

Protective role of marine macroalgae extracts against STZ induced diabetic rats

Objective: To study the anti-diabetic activity of marine macroalgae extracts (n = 31), purification and characterization of sulphated galactopyran (SGP) from Gracilaria opuntia (FM4) in diabetic rats. Methods: The animals were separated into groups and STZ (55 mg/kg body weight) was used to induce diabetics. Glucose, HbA1c, insulin, C-peptide levels and in vivo antioxidant levels were estimated and histopathological studies were done in STZ-induced diabetic and marine macroalgae treated rats. Results: Based on glucose and HbA1c levels and in vivo antioxidant levels, among the 31 marine macroalgae extracts, FM4 has showed high anti-diabetic activity. Hence, FM4 was purified and characterized by 1H-NMR spectra and FT-IR as sulphated galactopyran. During the survival analysis, SGP at dose of 100 mg/kg showed significant (P < 0.05) survival rate and elevations in C-peptide and insulin levels. The histopathological modulations of SGP were observed in diabetic rat tissues such as liver, kidney and brain. Hence obtained results reveal that SGP treated diabetic rats has significant changes in C-peptide and insulin levels which regulates the blood glucose levels and recovered the histopathological changes. Conclusions: Marine macroalgae have significant anti-diabetic activity. Hence, they could be used as nutraceutical supplement or natural green remedy against diabetes mellitus.