Background/Objectives: Cancer remains one of the leading causes of mortality worldwide, while natural antioxidants have emerged as promising therapeutic agents in cancer treatment. Although fucoidan from brown algae shows anticancer potential, its efficacy is limited by bioavailability challenges, and the synergistic effects of combining it with gold nanoparticles remain unexplored. Methods: Fucoidan was extracted from Sargassum cinereum and Turbinaria decurrens. F-AuNPs were produced utilizing fucoidan as both a reducing and stabilizing agent. The nanoparticles were analyzed by UV-Vis spectroscopy, FTIR, TEM, XRD, DLS, TAG, and zeta potential evaluation. The antioxidant activity was evaluated by DPPH and FRAP tests. Cytotoxicity was determined against HepG2, THP-1, and BNL cells, utilizing MTT and SRB tests. Flow cytometry was utilized to assess the cell cycle, while molecular docking was carried out to examine binding to oncogenic proteins. Results: T. decurrens produced higher polysaccharides rich in fucoidan content (235.9 mg/g dry weight) and stated higher antioxidant activity (FRAP: 9.21 μg TE mg⁻¹; DPPH: 4.48 μg TE mg⁻¹) in comparison to S. cinereum. F-AuNPs showed potent cytotoxicity toward HepG2 cells, with IC₅₀ values and cytotoxicity toward HepG2 cells, with IC₅₀ values of 377.6 μg/mL for S. cinereum and 449.5 μg mL⁻¹ for T. decurrens. Molecular docking revealed robust binding of fucoidan to COX-2 (−7.1 kcal mol⁻¹) and TERT (−5.4 kcal mol⁻¹). Conclusions: Fucoidan and F-AuNPs reveal remarkable antioxidant and anticancer properties. Nanoparticle formulation greatly improves bioactivity, underscoring its promise as a synergistic approach for cancer treatment by influencing oxidative stress and cancer-associated pathways.

Hepatitis C virus (HCV) has infected 3% of the population worldwide and 20% of the population in Egypt. HCV infection can lead to hepatocellular carcinoma and death. The presently available treatment with interferon plus ribavirin, has limited benefits due to adverse side effects. Seaweeds have become a major source of new compounds to treat viral diseases. This work aimed to study the effect of four species of seaweeds as anti- HCV. The inhibition of lipid peroxidation was measured by evaluating the ability of seaweed extracts to scavenge the free radicals. The HepG2 cells were infected with the HCV and treated with each seaweed polysaccharide. Inhibition of viral replication was detected using the Real Time PCR (RT) qPCR. To explain the mode of the seaweed action on HCV, three modes of virus infections and seaweed polysaccharide treatments were applied. All treatments had the ability to inhibit the HCV with priority to Laurencia obtusa (82.36%), while the potentiality to scavenge the free radicals reached up to 81.5% with the Sargassum vulgare. Seaweed polysaccharide extracts may be helpful in exploring further gateways for antiviral therapy against HCV.

Background: Cancer remains one of the leading causes of mortality worldwide, while natural antioxidants have emerged as promising therapeutic agents in cancer treatment. Although fucoidan from brown algae shows anticancer potential, its efficacy is limited by bioavailability challenges, and the synergistic effects of combining it with gold nano-particles remain unexplored. Methods: Fucoidan was extracted from Sargassum cinereum and Turbinaria decurrens using acid precipitation. Gold nanoparticles (AuNPs) were manufactured by a green technique that employed fucoidan as both a reducing and stabilizing agent. The nanoparticles were analyzed utilizing UV-Vis spectroscopy, FTIR, TEM, XRD, and zeta potential assessment. Antioxidant activities were evaluated utilizing DPPH and FRAP assays. Cytotoxicity was assessed against HepG2, THP-1, and BNL cells utilizing MTT and SRB tests. Flow cytometry was utilized for cell cycle analysis, and molecular docking was applied to examine interactions with cancer-associated proteins. Results: T. decurrens yielded higher fucoidan extraction (235.9 mg/g dry weight) and demonstrated superior antioxidant activity in Ferric Reducing Antioxidant Power (FRAP) (9.21 μg Trolox Equivalents /mg) and 2, 2-Diphenyl-1-Picryl-Hydrazyl-Hydrate (DPPH) (4.48 μg Trolox Equivalents /mg) assays compared to S. cinereum. Molecular docking revealed strong binding of fucoidan to cancer-related proteins, particularly COX-2 (-7.1 kcal/mol) and TERT (-5.4 kcal/mol), while the fucoidan-gold nanoparticle complex (F-AuNPs) showed enhanced cellular uptake and improved cytotoxicity against HepG2 cells (IC50: 392.81 μg/mL and 459.75 μg/mL for S. cinereum and T. decurrens formulations, respectively). Conclusions: These findings suggest a promising synergistic approach for enhancing fucoidan-gold nanoparticle therapeutic potential in cancer treatment through combined in vitro and in silico analyses.

Purpose: This study sought to extract and characterize fucoidan from brown seaweed Padina tetrastromatica for the synthesis of fucoidan–gold nanoparticles (F-AuNPs) and to assess their physicochemical properties, as well as their antioxidant, anti-inflammatory, and anticancer activities, alongside potential molecular interactions with specific cancer-related targets. Methods: The extracted fucoidan-rich fraction was characterized for its sulfate content. Citrate-stabilized plain gold nanoparticles (plain AuNPs) were prepared and characterized as non-fucoidan nanoparticle controls. Comprehensive physicochemical characterization, including UV–Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic light scattering (DLS), zeta-potential analysis, and thermogravimetric analysis (TGA), was performed on the resultant fucoidan-functionalized AuNPs (F-AuNPs). Biological activities were assessed using different techniques: antioxidant potential (Ferric Reducing Antioxidant Power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays), anti-inflammatory effects (NO inhibition in macrophages), and anticancer efficacy against HepG2 cells (MTT and flow cytometry). Potential molecular targets relevant to these activities were further explored in silico using molecular docking against key cancer-related proteins, providing hypotheses for future experimental validation. Results: The fucoidan-rich fraction showed a sulfate content of 10.08%. Strong antioxidant activity was observed, especially in FRAP (11.20 ± 0.29 mg TE g⁻¹ DW). F-AuNPs exhibited enhanced cytotoxicity against HepG2 cells (IC₅₀ 138.1 µg mL⁻¹) compared to plain AuNPs (IC₅₀ 271.2 µg mL⁻¹) and the fucoidan-rich fraction (IC₅₀ 390.2 µg mL⁻¹), inducing G1 phase arrest. In addition, F-AuNPs reduced nitric oxide production in LPS-stimulated RAW 264.7 macrophages, reaching 21.42 ± 1.29% inhibition at 100 µg mL⁻¹. As an exploratory, hypothesis-generating step, an in silico target-prioritization screen identified HPSE and MMP-2 as the highest-scoring candidate proteins, proposed solely as targets for future experimental validation. Conclusions: F-AuNPs represent a promising multifunctional nanoplatform with antioxidant, anti-inflammatory, and antiproliferative activities. The integration of in vitro biological evaluation with in silico target prediction supports the potential biomedical relevance of F-AuNPs and generates testable hypotheses regarding their molecular targets, which require experimental validation.

This special issue of IJCBR “Role of postgraduate researchers in advancing cancer and biomedical research” aims to raise awareness of the importance of postgraduate scientific research in the fields of cancer and biomedical research among scholars and junior researchers. There is always a need to discover safe natural materials or novel synthetic compounds to treat different types of cancer as well as other diseases.The research works presented in this special issue include abstracts from masters' and PhD theses on six topics Anticancer therapeutics, Cancer biology and immunology, Drug discovery, Biological activities of biochemicals, Nanotechnology, and Medicine and Nursing. Overall, I do believe that the scientific findings from the thesis are of great importance and added new values for the biomedical research in general and cancer research in particular. The studies presented several natural and chemical compounds with different biological activities, including anti-diabetic, anti-microbial, anti-cancer, as well as immune enhancer, opening new avenue for drug discovery. These studies highlight that fundamental role of postgraduate students in advancing biomedical research and innovation.