Hydraclathratus clathratus was assessed for phytochemical fingerprinting and multifunctional bioactivity, including antioxidant, antibacterial, and carbohydrate hydrolysing enzyme inhibition.

Abstract

Marine macroalgae represent a valuable source of natural bioactive compounds with potential applications in pharmaceutical, biomedical, and nutraceutical research. The present study investigated the preliminary phytochemical composition and antioxidant, antibacterial, and antidiabetic activities of the hydroalcoholic extract of Hydraclathrus clathratus (HCAE). Preliminary phytochemical screening revealed the presence of several major classes of secondary metabolites and other biologically relevant constituents, including saponins, glycosides, tannins, flavonoids, proteins, amino acids, phenolic compounds, lipids, and steroids. The antioxidant potential of HCAE was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging assays. The extract exhibited concentration-dependent radical-scavenging activity, with IC₉₀ values of 67.970 µg/mL for DPPH and 58.718 µg/mL for ABTS, indicating its capacity to neutralize free radicals under the experimental conditions. The antibacterial activity of HCAE was assessed against four bacterial pathogens, namely Escherichia coli, Klebsiella pneumoniae, Vibrio cholerae, and Staphylococcus aureus. The observed antibacterial effects suggest that the extract contains constituents with potential inhibitory activity against both Gram-negative and Gram-positive bacteria. Furthermore, the antidiabetic potential of HCAE was investigated by evaluating its inhibitory effects on α-amylase and α-glucosidase, two carbohydrate-hydrolysing enzymes involved in postprandial glucose regulation. The extract demonstrated enzyme-inhibitory activity, with IC₉₀ values of 56.562 µg/mL for α-amylase and 59.006 µg/mL for α-glucosidase. These findings indicate that HCAE possesses multiple biological activities that may be associated with its diverse phytochemical composition. In particular, its antioxidant activity, antibacterial effects, and inhibition of carbohydrate-digesting enzymes highlight the potential of H. clathratus as a candidate for further natural-product research. However, isolation and structural characterization of individual bioactive compounds, toxicity assessment, mechanistic investigations, and in vivo validation are necessary to establish its efficacy, safety, and potential therapeutic applications. Overall, this study provides a preliminary scientific basis for exploring H. clathratus as a marine-derived source of biologically active compounds for future pharmaceutical and functional-product development.