Hepatoprotective Effects of Garcina kola (Bitter kola) against Paracetamol- Induced Oxidative Damage and Glycogen Degranulation in Hepatocytes of Adult Male Wistar Rats

Introduction: The liver is an organ with a particular function of synthesizing and storing glycogen from glucose and other sources. Paracetamol has a compound called acetaminophen that produces a toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI), which is capable inducing series of reactions that induces hepatotoxicity in the hepatocytes leading to an increased plasma liver enzyme level, distortion of the hepatic plates, oxidative stress in the liver and loss of glycogen deposition.

Aims: This study was carried out to determine the ability of Garcinia kola to exhibit glycogen deposition and granulation in the presence of liver injury using paracetamol.

Methods: The antioxidant and hepatoprotective activity of Garcinia kola were also analyzed using Glucose -6- phosphate dehydrogenase (G6PDH) and Aspartate Transaminase (AST) enzyme markers. The histoarchitectural changes of Glycogen granulation within the hepatocytes in various treatment groups was accessed using Periodic Acid Schiff’s Staining Protocol. Experimental animals were grouped into five groups: Group A is normal (control) rats; Group B is a hepatotoxic rat model derived by giving 200 mg/kg b.w. of paracetamol (PCM) for the last three days of experiment; Groups C, D and E were, respectively, pre-treated with 10 g, 20 g and 30 g/kg b.w. of Garcinia kola for 21 days before paracetamol was administered via gastric intubation for three days (200 mg/kg b.w. using olive oil as carrier).

Results: The results revealed that Garcinia kola pretreated rats induced a significant decrease at p<0.05 in serum level of liver marker enzyme aspartate transaminase, (AST) and as compared to the increase serum level in hepatotoxic model (B). There was also a significant increase in activity of glucose-6-phosphate dehydrogenase (G6PDH) in the hepatocytes of those pretreated with Garcinia kola (C, D and E) as compared to hepatotoxic model (B); Garcinia kola pretreated groups (C, D and E) has an increased glycogen granulation as compared to the degranulation in hepatotoxic group.

Conclusion: These results show evidence pointing to the glycogen depositing potentials, hepatoprotective and antioxidative activity of Garcinia kola.