Ultrasound-assisted extraction and purification of <i>B. harveyi</i> for the development of bioactive wound healing gel: In vitro evaluation

Marine macroalgal biomass is abundant and contains multifunctional bioactive components. Bostrychia harveyi, one of the underutilized seaweeds, was collected and extracted by the ultrasonication process. UV-visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and high-performance liquid chromatography (HPLC) were carried out to confirm functional groups and structural features. A novel wound healing gel was prepared using carrageenan incorporated with a flavonoid-rich extract from B. harveyi. The bioactivity of the extract and gel was assessed with standard in vitro assays. 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH) of the gel and ascorbic acid (standard) showed inhibitory concentrations (IC50) of 67.05 µg/mL and 50.48 µg/mL. The phosphomolybdenum reduction activity of gel and ascorbic acid showed inhibitory concentrations (IC50) of 61.71 and 48.51 µg/mL. The bovine serum albumin denaturation by the gel and diclofenac sodium exhibited a maximum inhibition of 83.47% and 93.6% at 100 µg/mL, confirming a significant anti-inflammatory property. The antibacterial activity was confirmed using an agar well diffusion assay, indicating maximum inhibition of E. coli compared to S. aureus. The scratch wound assay using the L929 fibroblast showed 98.25% scratch closure after 48 hours, highlighting the preliminary effectiveness of the gel through its natural bioactive compounds and serving as a sustainable alternative in wound healing.