Investigation of protective efficiacy of artichoke (Cynara scolymus L.) leaf extracts against hepatotoxicity induced by cyclophosphamide in rats

As the liver is the detoxification center in metabolism, it is the organ most exposed to damage by toxic metabolites. In traditional medicine, the use of artichoke (Cynara scolymus L.) and leaves, which contain bioactive substances, to eliminate the negative effects of toxic metabolites of therapeutic drugs in the liver is quite common. In the light of this information, it was aimed to evaluate the protective efficacy of C. scolymus leaves against cyclophosphamide (CP)-induced acute hepatotoxicity in rats. The protective efficacy of extracts prepared against CP-induced hepatotoxicity in rats was determined using routine biochemical parameters (AST, ALT, ALP, total protein (TP), and total bilirubin (TB)), liver histopathology, oxidant-antioxidant levels (MDA, GSH, GPx, and SOD), and levels of cytokines (IL-1β, IL-10, and TNF-α). In addition, antioxidant activities of the three extracts were measured by various in vitro experiments, including total phenolic content, DPPH radical scavenging activities, superoxide radical scavenging activities and metal binding activities. To determine the phenolic contents of the extracts, Liquid Chromatography - Quadrupole Time of Flight Mass Spectrometry (LC-QTOF-MS) method was utilized. The findings of the LC-QTOF-MS analysis revealed that the EtOAc extract had higher concentrations of luteolin-7-O-glycoside, apigenin 7-glycoside, apigenin, oxooctadecatrienoic acid, hydroxy octadecatrienoic acid, and hydroxy octadecadienoic acid compounds compared to the MeOH extract. On the other hand, only the EtOAc extract had higher concentrations of apigenin-7-O-rutinoic acid compounds. In the in vitro antioxidant activity assays, the total phenolic content of the MeOH, EtOAc, and n-hexane extracts were 5,735 mg, 0.917mg, and 0.167 mg gallic acid (GAE)/g extract, respectively. The MeOH extract showed the highest DPPH radical scavenging activity (87.73%), the EtOAc extract showed the highest superoxide radical scavenging activity (49.02%), and the n-hexane extract showed the highest metal binding activity (289.32 μM Fe). In the in vivo experiments of the study, it was determined that the administration of CP increased the levels of plasma transaminases, T. protein, MDA, TNF-α and IL-1β, and decreased GSH, GPx, SOD and IL-10. While AST, ALT and ALP levels were statistically decreased in all extract groups compared to the CP group, T. protein level decreased only in the EtOAc group. Changes in T. bilirubin levels were found to be insignificant in all experimental groups compared to the control. In the study, plasma and liver tissue MDA, TNF-α and IL-1β levels decreased in MeOH group compared to CP group, while GSH (except liver tissue), GPx, SOD and IL-10 levels increased statistically. In the EtOAc group, only liver tissue MDA levels were low and plasma GSH levels were high, and all cytokine levels were found to be insignificant. At the same time, all oxidant-antioxidant parameters and cytokine levels were found to be insignificant in the n-hexane group. Based on the histopathological results of the study, sinusoidal dilatation in the liver tissue, hyperemia in the vena centralis, vacuolar degeneration and abnormal changes in Kupferr cell activation were determined in the CP group, whereas in the EtOAc group, on the contrary, these abnormal changes in the liver tissue decreased significantly and tissue healing was achieved. While this improvement was seen in the form of hyperemia in the vena centralis and a decrease in vacuolar degeneration in the MeOH group, it was determined that tissue healing was very limited in the n-hexane group. The MeOH extract with high levels of phenolic substances has been found to be more effective against acute hepatotoxicity, increased inflammation, and oxidative stress caused by CP. In addition, the EtOAc extract, which contains a wider variety of phenolic substances, has been found to be more effective in tissue healing. On the other hand, n-hexane extract was found to be the most ineffective extract compared to other extracts in terms of antioxidants, cytokines and histopathological examinations. In conclusion, the present findings showed that especially MeOH extract of artichoke leaf offered curative effects against CP-induced hepatotoxicity damage in rats due to its antioxidant and anti-inflammatory properties.