Rabia Alghazeer1*, Ahmed Ibrahim2, Arwa Abdulaziz1, Karima Abouamer1
1Chemistry Department, Faculty of Sciences, University of Tripoli, Tripoli, Libya
2Chemistry Department, Azzawiya University, Azzawiya, Libya
A B S T R A C T
The main objective of this study was to investigate the in vitro antioxidant activities of three selected green (Codium tomentosum, Enteromorpha linza), red (Gelidium sesquipedale) and brown (Cystoseira spicata, Padina pavonica) seaweeds from western of Tripoli coast, Libya. After methanol extraction, polyphenol, flavonoids, and condensed tannins contents were assessed. Methanol extracts of the seaweeds were investigated for their total antioxidant activity, reducing power, DPPH radical scavenging activity, NO radical scavenging activity, deoxyribose scavenging activity, and nitric oxide radical inhibition assay. Brown seaweed especially C. spicata exhibited good antioxidant activity when compared to red and green seaweeds. The maximum antioxidant activity was shown by the methanol extract of C. spicata for DPPH and nitric oxide radicals scavenging assay (66%, and 53% respectively). Also C. spicata extract showed a noticeable protection levels against lipid peroxidation. However, extract of E. linza exhibited the lowest antioxidant activity. Macroalgae can be considered as a good source of natural antioxidants.
Keywords: Seaweeds, brown algae, red algae, green algae, Free radicals, antioxidant activity.