Marrubiin-loaded solid lipid nanoparticles' impact on TNF-α treated umbilical vein endothelial cells: A study for cardioprotective effect.

Oxidative stress possesses a key role in the onset and development of cardiovascular diseases (CVDs), thus it can be an efficient target to tackle such ailment. Marrubiin, a bioactive diterpene, is a potent antioxidant against oxidative stress. Herein, we aimed to formulate marrubiin loaded solid lipid nanoparticles (SLNs) to improve its pharmacokinetics and bioavailability and also to investigate free drug and formulation's protective impact against intracellular reactive oxygen species (ROS) generation in HUVECs. Marrubiin-SLNs were formulated using hot homogenization/solidification method and then were subjected to physicochemical characterizations, i.e. size, zeta potential, morphology, polydispersity index (PDI), encapsulation efficiency (% EE), drug loading/content and physical stability assessments. MTT assay was performed to study the cytotoxicity of the intact and SLN incorporated marrubiin on HUVECs. Further, the antioxidant property of marrubiin and formulations was evaluated using DPPH radical scavenging assay and their protective effect against TNF-α induced oxidative stress was assessed by the means of intracellular ROS assessment, and also apoptosis/necrosis, cell cycle, and DNA fragmentation assays. Electron microscopy analysis showed spherical monodispersed SLNs with the size less than 100 nm, particle/zeta size analyses also approved the size of particles with a zeta potential of -1.28 ± 0.17 mV. Results also showed high EE (98%), drug loading (31.74 mg/g) with 3.15% drug content. In vitro release studies revealed about 90% of marrubiin cumulative release during 24 h. The stability of marrubiin-SLNs in terms of size, zeta potential, polydispersity index, EE and drug leakage was approved. Marrubiin antioxidant stability after formulation was approved by DPPH analysis. MTT cell survival assay showed no significant cytotoxicity after 24 h and 48 h. Intracellular ROS detection assay revealed that marrubiin and marrubiin-SLNs, play protective effect against TNF-α induced oxidative stress in HUVECs which was further approved by apoptosis assessment. Conclusively, based on our findings, marrubiin nanoparticles are proposed as a preventive/therapeutic remedy against disorders elicited by increased levels of intracellular ROS in CVDs.