Evaluation of the Antioxidative and Hepatoprotective Activity of Ulva lactuca in a CCl4-Induced Liver Injury Model

Background: Ulva lactuca is abundant in bioactive components that provide antioxidative, anti-inflammatory and hepatoprotective properties against oxidative stress. Objectives: This study aimed to explore the nutritional composition, antioxidative potential and hepatoprotective efficacy of U. lactuca in a CCl4-induced liver injury model. Methods: Proximate analysis, phytochemical profiling (phenolic and flavonoid content, GC-MS and LC-MS) and antioxidant assays (DPPH and FRAP) were performed, followed by an in vivo efficacy trial. Hepatotoxicity was induced using CCl4, and U. lactuca methanolic extract (1000 mg/kg body weight) was administered for four weeks. Results: The proximate analysis demonstrated 10.5% ash, 10.83% protein and 39.43% fibre. GC-MS and LC-MS identified hexadecanoic acid methyl ester, gallic acid, quercetin, quercitrin, 4-hydroxybenzoic acid and syringic acid. TPC was higher in aqueous (2015.1 mgGAE/100 mL) and TFC in ethanolic (750.5 µgQE/mL) extract. Aqueous extract (170.1 ± 0.1 µmol/g) displayed superior reducing power while ethanolic extract (77.7%) exhibited the highest radical scavenging activity. U. lactuca promoted weight recovery, improved lipid profiles, decreased hepatic and oxidative stress biomarkers (p-value < 0.05), and restored liver histology. Conclusions: U. lactuca showed promising effects against sub-chronic liver injury, primarily due to its rich nutritional profile. Thus, its incorporation into the Pakistani diet may reduce disease and economic burden while supporting functional food and nutraceutical industries.