Preliminary assessment of the antioxidant, anti-inflammatory, antidiabetic, and anti-carcinogenic attributes of Australian red seaweeds

Red seaweeds contain an assortment of valuable phytochemical; however, while their pharmaceutical and therapeutic potential has been previously recognized, many aspects of their bioactive properties remain underexplored, especially among the Australian species. An ultrasonic-assisted extraction method was used to obtain polyphenol-rich extracts from thirteen Australian red seaweeds. Antioxidant activity and antiinflammatory potential, assessed through assays such as urease inhibition and nitric oxide scavenging, as well as anti-diabetic capacity through alpha-amylase and alpha-glucosidase inhibition, were evaluated. Rhodophyllis sp. demonstrated the greatest antioxidant capacity with relative antioxidant capacity index score of 1.43, while Crouania attenuata exhibited superior antidiabetic effects through alpha-glucosidase and alpha-amylase inhibition. Notable anti-inflammatory potential was observed in Plocamium and Asparagopsis samples, with A. armata excelling in protease inhibition. Moreover, LC-ESI-QTOF-MS/MS analysis of the extracts tentatively identified 26 polyphenols, indicating the rich bioactive profile of these marine resources. The in vitro assays and phenolic composition highlight the considerable biological potential of Australian Rhodophyta, emphasizing the need for further exploration of these red seaweeds as promising candidates for therapeutic and pharmaceutical applications.