POSSIBLE PROTECTIVE EFFECT OF ALPHA LIPOIC ACID AGAINST RICIN INDUCED HEPATOTOXICITY IN ADULT MALE ALBINO RATS

Introduction: Ricin is one of the most potent and deadly plant toxins known. It induces oxidative stress and was exploited as a poison for bioterrorism due to its characters. Developing an effective antidote for ricin toxicity becomes a reliable way against its potential biothreat. Alpha lipoic acid (ALA) being an ideal antioxidant, was chosen as protection against ricin toxicity. Aim of the work: The current study was carried out to confirm the hepatotoxic effect of ricin using the electron microscope (EM) and to assess the potential protective effect of ALA against ricin hepatotoxicity and lethality. Material and methods: The current study was conducted on 60 adult male albino rats. Rats were divided into four groups. The first group (10 rats) was used as control group. Group II (10 rats) was injected with ALA (100mg/kg intraperitoneal). Group III (20 rats) was injected once with ricin (25ug/kg subcutaneous). Group IV was injected with ALA (100 mg/kg) 15 minute prior to and immediately after ricin injection. Survival time was recorded and liver samples were taken for examination under EM. Results: Injection of ALA together with ricin significantly prolonged the survival time of the rats in group IV more than those in group III. Electron microscopic examination of liver specimens obtained from group III revealed hepatocytes with either euchromatic nuclei, shrunken hyperchromatic nuclei or nuclei with marginated chromatin. Hugely dilated degranulated rough endoplasmic reticulum (RER), many lipid droplets and electron dense mitochondria were detected. Treatment of animals with ALA resulted in less ultra structure damage. The hepatocytes showed either euchromatic nuclei or nuclei with marginated chromatin. Their cytoplasm exhibited slightly dilated RER, electron dense mitochondria and some vacuoles. Conclusion: It was concluded that ricin is a hepatotoxic substance causing ultra structure damage. Furthermore, ALA proved to be beneficial in prolonging the survival time and decreasing the toxic effect of ricin on the liver. Recommendations: Further studies are recommended to detect the underlying mechanism of ricin hepatotoxicity and to find more protective substances against ricin toxicity