Phytochemical analysis, antibacterial and anti-diabetic activity of three different seaweed extracts

Aim: Marine seaweed contains potential phytochemical compounds that could able to cure different health issues in humans naturally. Hence the research was aimed to investigate the antibacterial and in vitro anti-diabetic activity of three different seaweed extracts. Methods: Phytochemical compounds like phenol, flavonoids, tannins and alkaloids were quantitatively identified. Antibacterial activity of the seaweed extracts were determined against five different test bacteria. In vitro anti-diabetic activity of the extracts were investigated based on its inhibition effect on the alpha-amylase and alpha-glucosidase activity. Findings: Phytochemical analysis showed more phenolic and flavonoid content in green and brown seaweed extracts and lesser content in red seaweed extract. Antibacterial activity of green and brown seaweed extracts showed good inhibitory zones against all test bacteria ranging from 22.9 ± 0.57 mm to 24.9 ± 0.57 mm (green seaweed extract) and 17.9 ± 0.57 mm to 21.6 ± 0.75 mm (brown seaweed extract) respectively. In vitro anti-diabetic activity of seaweed on the inhibition of enzymes showed promising results. Among the three types, green seaweed extracts showed maximum inhibition of α-Amylase and α-glucosidase activity of 86.6 ± 0.76 % and 82.9 ± 0.57 % respectively. Conclusion: Findings showed that the phytochemicals present in the methanolic extract of seaweeds attribute positively for different pharmacological properties like antibacterial, anti-oxidant and anti-diabetic activity. Optimizing the production factors would able to commercialize the seaweeds in drug forms and could be used for the treatment of various diseases in humans.