Comparison of the effects of thymoquinone and silymarin on the brain of rats having ischemia-reperfusion in the lower extremities.

Aim: We aimed to show whether ischemia reperfusion (I/R) injury causes damage on brain or not, and whether thymoquinone and silymarin, as antioxidant and anti-inflammatory herbs, have beneficial effects on this damage or not.
Methods: Forty Wistar albino rats were carried out and were randomized to 4 groups with equal numbers (n=10): sham group, implemented of only anesthesia; control group, implemented of anesthesia and I/R injury; silymarin group, implemented of anesthesia and I/R injury and treated with a dose of 200 milligram/kg silymarin ip and thymoquinone group, implemented of anesthesia and I/R injury and treated with a dose of 20 mg/kg thymoquinone. Serum lipid hydroperoxide (LOOH) and total free sulfhydryl (Sh) levels were determined. Light microscopy was used to evaluate histological changes in brain tissue.
Results: Serum LOOH levels (0.21 ± 0.04 for control group, 0.29 ± 0.01 for sham group, 0.23 ± 0.09 for silymarin group, 0.29 ± 0.09 for thymoquinone group) were significantly higher and Sh levels (10.74 ± 1.71 for control group, 6.82 ± 0.24 for sham group, 9.12 ± 1.04 for silymarin group, 8.41 ± 1.12 for thymoquinone group) were significantly lower in control, silymarin and thymoquinone groups compared to control group (p<0.05 for all). According to the histopathologic damage score assessment, it was seen that the damage decreased significantly in the silymarin and the thymoquinone groups.
Conclusion: We showed that tissue damage also occurs in brain following the ischemia reperfusion. It was shown that thymoquinone and silymarin is quite effective in preventing this damage.
Key Words: Brain, Hydroperoxide levels, Ischemia reperfusion injury, Sulfhydryl levels, Silymarin, Thymoquinone.