Inhibition by folic acid of tumor necrosis factor alpha and apoptosis following normothermic ischemia-reperfusion

Folate is necessary for the production and maintenance of new cells and important during periods of rapid cell division and growth. Tumor necrosis factor-alpha (TNF-alpha) is known as a stimulant of apoptotic cell death. The present study was aimed to evaluate the efficacy of folic acid (CAS 59-30-3) in prevention of apoptosis by inhibiting TNF-alpha action in ischemia-reperfusion (I/R) induced liver injury. Eighteen Wistar rats were subjected to I h of hepatic ischemia followed by 3 h reperfusion and were divided into sham-operated control Group (I) (n = 6), ischemia and reperfusion group administered 0.9% saline (5 ml/kg, p.o.) for 7 days (II) (n = 6), folic acid treated group (I mg/kg body weight/treated daily by oral route for 7 days before induced ischemia-reperfusion maneuver) (III) (n = 6). Hepatic damage in rats was assessed in terms of serum alanine transaminases and aspartate transaminases. TNF-alpha concentration was measured in serum by enzyme linked immuno assay. Necrosis and apoptosis were measured by flow cytometry and fluorescence microscopy. Apoptotic marker Bcl-2 gene expression was measured by reverse transcriptase polymerase chain reaction (RTPCR) and Western Blot Analysis. Pathological changes were measured by transmission electron microscopy (TEM). Serum alanine transaminase (ALT), aspartate transaminase (AST) and TNF-alpha concentration increased significantly (p < 0.05) in rats with I/R induced injury as compared to sham operated control rats. Pretreatment with folic acid effectively counteracted the alternation in hepatic enzymes. TEM, expression of Bcl-2 protein and flow cytometry studies confirmed the restoration of cellular normalcy and accredits the cytoprotective role of folic acid against I/R induced hepatic injury. The present study demonstrated that elevated TNF-alpha activity directly related to apoptosis and folic acid inhibits apoptosis by inhibiting the action of TNF-alpha.