Uzma Ghani ¹ Fareeha K. Ghori ^1* Muhammad Usman Qamar ² Hina Khan ¹ Basit Azad ^1* Sabahat Habib ^1* Saira Justin ¹ Ishaq N. Khan ^3* Tawaf Ali Shah ⁴ YOUSEF A BIN JARDAN ⁵ Mohammed Bourhia ⁶ Fouzia Perveen ^1* Aneela Javed ^1*

• ¹ National University of Sciences and Technology (NUST), Islamabad, Pakistan
• ² University of Geneva, Geneva, Geneva, Switzerland
• ³ Khyber Medical University, Peshawar, Khyber Pakhtunkhwa, Pakistan
• ⁴ Shandong University of Technology, Zibo, Shandong, China
• ⁵ King Saud University, Riyadh, Riyadh, Saudi Arabia
• ⁶ Faculty of Medicine and Pharmacy, Ibn Zohr University, Agadir, Morocco

Glioblastoma is a grade IV solid brain tumor and has a 15-month survival rate even after treatment. Glioblastoma development is heavily influenced by Retinoblastoma protein (pRB) pathway changes. The Blood-brain barrier (BBB), drug resistance, and severe toxicity of Temozolamide (TMZ) are key obstacles in treating Glioblastoma. Innovative treatments targeting the pRB pathway with efficient delivery vehicles are required to treat Glioblastoma. For this purpose, a library of 691 plant extracts previously tested in-vitro for anti-cancerous, antiinflammatory, and anti-proliferative characteristics was created after thorough literature investigations. Compounds were docked against pRB pathway protein ligands using MOE and Chimera. Their nuclear structure and drug-like properties were predicted through Lipinski rule and DFT analysis. Silymarin (Sil) was identified as the most potent compound against CDK4 which was then encapsulated in Stearic acid solid lipid nanoparticles (SLNP-Sil). Physiochemical characterizations of naked and drug-encapsulated SLNPs assessed size, stability, entrapment efficiency, and drug release rate. Anti-cancer potential of drug and drug loaded SLNPs were evaluated using U87, U251 and HEK cell lines. Sil showed decreased cell viability 72hrs post treatment, against both U87 and U251 cell lines but had negligible cytotoxic effect on HEK-293. IC50 value of Sil was 155.14mu for U87 and 195.93mu for U251. Formulations were tested for cancer cell metastatic potential using cell migration assays. Sil and SLNP-Sil effectively inhibited U87 and U251 cell migration 24hrs after treatment. In conclusion, our results indicated Sil and SLNP-Sil are promising therapeutic approaches against Glioblastoma, merit in-vivo experimental verification using orthotropic xenograft mouse models against Glioblastoma.