Multifunctionality of Ulvan derived from Ulva lactuca: Biochemical, Organoleptic, Structural characterization and Biomedicinal Properties

Santhiyagu Prakash^1*Sonalismita Mahapatra¹RAMASAMY RAMASUBBURAYAN²Thirumurugan Durairaj³Ethiraj Kannapiran⁴Grasian Immanel⁵Chandran Aanad¹Selvaraj Bharathi⁶

• ¹Tamil Nadu Dr J Jayalalithaa Fisheries University, Nagapattinam, India
• ²SIMATS Deemed University Saveetha Dental College, Chennai, India
• ³SRM Institute of Science and Technology (Deemed to be University) Research Kattankulathur, Kattankulathur, India
• ⁴Alagappa University, Karaikudi, India
• ⁵Manonmaniam Sundaranar University, Tirunelveli, India
• ⁶Sathyabama Institute of Science and Technology (Deemed to be University), Chennai, India

The increasing prevalence of antimicrobial resistance (AMR), alongside the heightened level of cancer, diabetes and adverse effects associated with antibiotics, chemotherapy and synthetic drugs, encourages researchers to find out natural products as a potential solution. In this context, an attempt has been made to extract, partially purify, and ulvan from the green algae Ulva lactuca and determine its biomedicinal properties. The organoleptic characteristics of ulvan revealed that it is odourless, whitish in colour, polar, powdery, and possesses gelling ability. Biochemical analyses indicated that ulvan exhibited high thermal stability under conditions ranging from 103.6 to 600°C, with a near-neutral pH of 6.7–7.4, and contained substantial amounts of carbohydrates (47.04%), alongside sulfate groups (20.1%), uronic acids (19.03%), and proteins (11.84%). Spectroscopic analysis, including TLC, UV-Vis, FT-IR, NMR, XRD and TGA, demonstrated the structural makeup and functional groups in the ulvan. The extracted ulvan exhibited promising radical scavenging properties, as evidenced by DPPH (IC50: 29.5 µg/mL), FRAP (IC50: 23.44 µg/mL), HPO (IC50: 77.15 µg/mL), and TAA tests. Antimicrobial studies revealed that ulvan inhibited both bacterial and Candida strains, with MICs in the range of 50 to 90 µg/mL. It also exhibited notable antibiofilm activity, as confirmed by the inhibition of exopolysaccharide, enhanced protein leakage, and ROS production in the tested pathogens. Antibiofilm study by microscopic visualization revealed a substantial eradication of bacterial adherence. The in vitro antidiabetic property of ulvan, as demonstrated by its α-amylase inhibitory activity, showed an IC₅₀ value of 78.43 µg/mL. The safety assessment of ulvan indicated a low level of hemolysis (IC50:12.1 µg/mL) as evidenced by the hemolytic index and minimal Artemia salina nauplii toxicity. Cytotoxic evaluation of ulvan on A431 human skin carcinoma cells recorded an IC₅₀ value of 82.44 µg/mL. Overall, the present study demonstrated the structural characterization of ulvan and its notable biomedicinal and biocompatibility, emphasize their potential application in pharmacology and therapeutics.