Thymoquinone loaded zinc oxide Nanoformulations synthesis, characterization and evaluation of their efficacy against carbon tetrachloride induced Hepatorenal toxicity in rats

Thymoquinone (THQ), a strong antioxidant and anti-inflammatory bioactive compound has been reported in numerous studies to prevent the hepatorenal toxicity caused by various xenobiotics. Similarly, the zinc oxide nanoparticles (ZnONPs) have been used to protect against the hepatorenal damages caused by oxidative stress due to their potent antioxidant properties. The aim of this study was to synthesize and investigate the possible protective effects of THQ, ZnONPs and THQ-loaded ZnONPs against CCl₄ induced hepatorenal toxicity in albino rats. ZnONPs and THQ-loaded ZnONPs were synthesized and characterized by various techniques. For the in-vivo study, thirty albino rats were randomly divided into five groups of six rats each. The control group received normal saline and 2^nd group (injury group) received CCl₄ only. The 3^rd group (T1-group) received CCl₄ + ZnONPs, the 4^th group (T2-group) received CCl₄ + THQ, and the 5^th group (T3-group) received CCl₄ + THQ-loaded ZnONPs. Renal and hepatic biomarkers (total bilirubin, AST, ALT, ALP, blood urea nitrogen and creatinine), lipid profiles, antioxidant levels and histopathological studies were investigated. The synthesized NPs showed a spherical shape with an average size of 16-30 nm and exhibited hexagonal structures. Results showed that THQ-loaded ZnONPs resulted in a decrease in liver and kidney biomarkers as well as a reduction in TC, TG, and LDL levels compared to groups received ZnONPs and THQ alone. CAT, SOD, GR and DPPH-radical scavenging ability were maintained at normal levels in group T3, which received THQ-loaded ZnONPs compared to T1 and T2 groups. Hepatic histopathological analysis revealed a reduction in hydropic degeneration and hepatocyte congestion in the central veins, alongside a decrease in tubular cell swelling and normalization of renal histology in the THQ-loaded ZnONPs groups. In conclusion, results of this investigation demonstrate that THQ-loaded ZnONPs can act as an efficient protectant and antioxidant against oxidative stress and hepatorenal toxicity caused by various xenobiotics.