Hepatic ischemia reperfusion injury remains a significant problem for hepatic surgical procedures and also remains a limitation of liver transplantation. It is important to reduce ischemia reperfusion injury. Oxygen free radicals, produced on reperfusion, play a critical role in the injury caused by ischemia-reperfusion. Reactive oxygen radicals lead to an inflammatory response and tissue damage by activating various mediators. It can also directly damage cellular components. Various agents, such as antioxidants and antiinflammatories, have been investigated to reduce the injury. However, there is no study demonstrating the effects of Nigella sativa on liver tissue against ischemia reperfusion injury.
A research article to be published on September 7, 2008 in the World Journal of Gastroenterology addresses this question. The research team led by Assistant Prof Yildiz and his colleagues in Harran University Medical School (Sanli Urfa/ Turkey) investigated whether Nigella sativa, which have been described to have various therapeutic effects, such as antioxidant, anti-inflammatory, anticancer, antihistaminic, antibacterial effects, protects the liver against the hepatic ischemia reperfusion injury.
In this experimental study rats underwent hepatic ischemia for 45 min followed by 60 min period of reperfusion. Rats were intraperitoneally infused with only 0.9% saline solution in the control group. Rats in the treatment group received NS (0.2 mL/kg) intraperitoneally, before ischemia and before reperfusion. Blood samples and liver tissues were harvested from the rats, and then the rats were sacrificed. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) levels were determined. Total antioxidant capacity (TAC), catalase (CAT), total oxidative status (TOS), oxidative stress index (OSI) and myeloperoxidase (MPO) in hepatic tissue were measured. Also, liver tissue histopathology was evaluated by light microscope.
The levels of liver enzymes in the treatment group were significantly lower than those in the control group (P < 0.01). TAC in liver tissue was significantly higher in the treatment group than in the control group (P < 0.05 and P < 0.05, respectively). TOS, OSI and MPO in hepatic tissue were significantly lower in the group 3 than the group 2 (P < 0.05 for all). Histological tissue damage was milder in the Nigella sativa treatment group than that in the control group. These results suggest that NS treatment protects the rat liver against to hepatic ischemia-reperfusion injury.
Nigella sativa has no side effects. Therefore, it may become a treatment choice in conditions which hepatic ischemia reperfusion is expected. However, further studies are required to establish its feasibility in clinical conditions.
In the present study, the authors investigated the effects of Nigella sativa, an annual flowering plant, on hepatic ischemia-reperfusion injury. The late effects of Nigella sativa should be evaluated and survival experiments would be helpful.