Pathological changes induced by the venom of Echis ocellatus in experimentally envenomed Swiss-Albino mice

Abstract

Introduction: Echis ocellatus (Family Viperidae) is the most medically important snake in Nigeria, accounting for over 60% of snake envenomation in the country. However, in spite of its significance, the snake has been under reported. The paucity of information on the pathologic effects of the snake species in animals necessitates this study to unravel the gross pathological changes, histological and haematological alterations associated with its envenoming. Methods: A total of 10 Swiss-albino mice of average weight 30 g were divided into two groups of five mice each. Group A were experimentally envenomed at 2.7 mg/kg (LD50) using crude venom extract of the snake, while group B mice were administered normal saline (placebo) intraperitoneally. The mice were observed for clinical signs of envenomation and thereafter sacrificed to collect blood, followed by post-mortem examination. Results: Stretching, shivering, restlessness and dry gangrene were the clinical signs observed in the envenomed mice, while generalised congestion of the entire internal organs, haemorrhages and unclotted blood within both abdominal and thoracic cavities were seen grossly. Congested liver with focal areas of necrotised hepatocytes, mononuclear cellular infiltrations, splenic megakaryocytes, necrosis of myocardium and renal epithelium were the histological findings recorded. Haematological examination revealed; marked anaemia and significantly (p < 0.05) higher total plasma protein in the envenomed group. Significance: The present study documents experimental envenoming by E. ocellatus in Albino mice. Findings may be beneficial in diagnosis and designing of effective therapy. Further research into the bioactivity of the snake venom is recommended.