In the present study, we examined the protective effects of CaD treatment against hepatorenal damages caused by CCL4 in mice. In line with former studies, it has been shown that CCL4 treatment causes significant hepatorenal injuries as indicated by the heightened levels of liver and kidney indices, namely BUN, ALT, AST, and Cr (Venkatanarayana et al., 2012, Mohseni et al., 2019). Our results also showed that CCL4 increases the MDA levels as well as GPx, SOD, and TAC activities in the liver and kidney. Moreover, the liver and kidney histological results are in accord with the abovementioned changes in the biochemical and oxidative factors. The results of our study confirm that administration of CaD at the dose of 100 mg/kg reduced the hepatorenal injuries induced by CCL4 via reducing the levels of BUN, Cr, AST, ALP, and MDA as well as increasing the activities of GPx, SOD, and TAC. Still, all biochemical and oxidative results were corroborated by histological findings of liver and kidney tissues. Hepatorenal damages can be verified via changes in serum biochemical parameters and tissue histopathology.
In accordance with our results, it has been reported that CCL4 induces pathological lesions that are related to biochemical alterations such as increased serum ALT, AST, ALP, Cr, and BUN quantities in the liver and kidney (Venkatanarayana et al., 2012, Mohseni et al., 2019). In the present study, renal tubular necrosis, glomerular atrophy, renal leukocyte infiltration, hepatic congestion, sinusoid dilatation, and pyknosis of hepatocytes, in addition to increased abovementioned biochemical parameters in mice getting CCL4, can be regarded as proof of hepatorenal damage.
In our study, CaD treatment could reverse abnormal situation of serum Cr, BUN, ALT, and AST to normal levels, as well as histopathological lesions of liver and kidney tissues in CCL4 administered mice treated with CaD (100 mg/kg). Previous reports revealed that CaD has antioxidant properties (Garay et al., 2005). Seker et al. found that CaD has protective effects against intestinal ischemia-reperfusion injury via increasing the TAC indicator (Seker et al., 2016). CaD is a potent free radical scavenger and reduces the level of MDA (as a marker of lipid peroxidation) (Unal et al., 2019b). Besides, over-generation of MDA could result in functional and pathological changes in the kidneys and liver (Mehrzadi et al., 2018, Kaeidi et al., 2020b). The process of renal damage caused by CCl4 entails peroxidation of the cell membrane fatty acids, which initiates destruction of the cell and their intracellular organelles (Boll et al., 2001). It is widely recognized that oxidative stress triggers apoptosis (Hassanshahi et al., 2020), which results in liver and kidney degeneration (Hagen, 2003). Our results showed that CCL4 could induce apoptosis (via increasing Bax protein expression and lowering Bcl-2 protein expression level) in the kidney and liver organs (Figs. 1 and 2). However, CaD (100 mg/kg) could attenuate apoptosis in these organs (Figs. 1 and 2). In agreement with our study, Zhang et al. reported that CaD has an important role in inhibiting apoptosis factors in these organs (Zhang et al., 2015). Sola-Adell et al. found that CaD prevents neurodegeneration in diabetic retinopathy (Solà-Adell et al., 2017). In another study, it was revealed that treatment of diabetic rats with CaD reduced the retinal injury induced by ischemia/reperfusion by increasing the content of reduced glutathione and oxidized glutathione (Szabo et al., 2001). In another study, CaD increased kidney ferric reducing antioxidant power in nephrotoxicity induced by gentamicin (Jafarey et al., 2014). Besides, latest studies have verified that CAD exerts protective effects against diabetic nephropathy (Zhang, 2013) and gentamicin-induced acute kidney injury (Jafarey et al., 2014).
Conclusion: The present study measured the protective effects of CaD with specific reference to its impacts against oxidative stress (using levels of MDA as well as activities of CAT and GPx) after CCL4-induced damage in mice liver and kidneys. CaD treatment gave sufficient protection through serum and tissue biochemical and histopathological alterations. But, additional studies must be performed to improve understanding of the mechanisms and degree of this protective effect.