Potential of CME@ZIF-8 MOF Nanoformulation: Smart Delivery of Silymarin for Enhanced Performance and Mechanism in Albino Rats

Silymarin, an antioxidant, is locally used for kidney and heart ailments. However, its limited water solubility and less oral bioavailability limit its therapeutic efficiency. The present study investigated the enhancement of solubility and bioavailability of silymarin by loading it in <i>Cordia myxa</i> plant extract-coated zeolitic imidazole framework (CME@ZIF-8) against carbon tetrachloride (CCl₄)-induced nephrotoxicity and cardiac toxicity in albino rats. The synthesized PEG-coated silymarin drug-loaded CME@ZIF-8 MOFs (PEG-Sily@CME@ZIF-8) were characterized by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, UV-visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and zeta potential. The average crystal size of CME@ZIF-8 and PEG-Sily@CME@ZIF-8 was 12.69 and 16.81 nm, respectively. The silymarin drug loading percentage in PEG-Sily@CME@ZIF-8 was 33.05% (w/w). In the animal model with CCl₄ treatment, different parameters like serum profile, enzymatic level, genotoxicity, and histopathology were assessed. Treatment with PEG-Sily@CME@ZIF-8 with different doses of 500, 1000, and 1500 μg/kg body weight efficiently ameliorated the alterations in the antioxidant defenses, biochemical parameters, and histopathological alterations and DNA damage in comparison to silymarin drug in a CCl₄-induced toxicity rat model via alleviating the cellular abnormalities and attenuation of normal antioxidant enzymes levels. Moreover, the molecular mechanism of drug-silymarin interaction with the target protein was investigated. It involves the binding pockets of silymarin molecules with VEGFR, TNF-α, NLRP3, AT1R, NOX1, RIPK1, Caspase-3, CHOP, and MMP-9 proteins, elucidating the silymarin-protein interactions by the formation of hydrogen bonds and hydrophobic interactions. This study suggests that the nanodrug PEG-Sily@CME@ZIF-8 MOFs protect the kidneys and heart possibly by mitigating oxidative stress more efficiently than the conventional drug silymarin.