Independent and synergistic activity of the flavonoids of Gracilaria corticata as promising antidiabetic agents

The therapeutic approaches for Type 2 Diabetes Mellitus rely most on the usage of oral hypoglycaemic drugs. These drugs have adverse side effects and hence alternative medicines are continuously explored. The present study intends to investigate the antidiabetic potential of the flavonoids present in Gracilaria corticata. The flavonoids were isolated (FEGC) and their inhibitory activity on the carbohydrate hydrolysing enzymes such as α-amylase and α-glucosidase was analysed. The flavonoids were found to inhibit α-amylase and α-glucosidase with an IC50 value of 302 µg and 75 µg respectively. The synergistic effect of FEGC and luteolin was also investigated and the results show that both FEGC and luteolin inhibited synergistically at half their IC50 values. The observations of this study reveal that the flavonoids of G. corticata have potential antidiabetic activity and can act independently or synergistically in the management of Type 2 Diabetes Mellitus

Chemical analysis and toxicity of seaweed extracts with inhibitory activity against tropical fruit anthracnose fungi.

BACKGROUND: Banana and papaya are among the most important crops in the tropics, with a value amounting to millions of dollars per year. However, these fruits suffer significant losses due to anthracnose, a fungal disease. It is well known that certain seaweed extracts possess antifungal activity, but no published data appear to exist on the practical application of this property. In the present study, five organic Brazilian seaweed extracts were screened for their activity against banana and papaya anthracnose fungi. Furthermore, cytotoxic and mutagenic effects of the extracts were evaluated by the brine shrimp lethality assay and the Allium cepa root-tip mutagenicity test respectively, while their major components were identified by gas chromatography/mass spectrometry. RESULTS: Strong fungus-inhibitory effects of Ochtodes secundiramea and Laurencia dendroidea extracts were observed on both papaya (100 and 98% respectively) and banana (89 and 78% respectively). This impressive activity could be associated with halogenated terpenes, the major components of both extracts. Only Hypnea musciformis extract showed cytotoxic and mutagenic effects. CONCLUSION: The results of this study suggest the potential use of seaweed extracts as a source of antifungal agents with low toxicity to control anthracnose in papaya and banana during storage.