Chemical and Quantitive Study of Hepatotoxins from Fresh Water Cyanobacteria on Vertebrate Animals

Abstract

Toxicity of the freeze-dried micro-aquatic planktonic cyanobacterium Oscillatoria agardhii, dominating and isolated from Makkah –KSA was studied. Microcystins were detected from freeze-dried cells using high pressure liquid chromatography HPLC. The histopathological examination of mice liver injected on week basis with diluted 1/5 of the lethal dose, (105 mg/ Kg body weight), of toxin extract revealed sever changes in liver histology and displayed apparent signs of degenerative hepatic structure. Cytoplasmic vacuolation and parenchyma exhibit hepatocytes degeneration. Hepatic vasculature and biliary system were blocked and severely damaged. The effect of the extract on blood contents and liver function of white mice was investigated. Mice were divided into three groups and injected intraperitoneally (i.p) with weekly reciprocal doses of toxin extract as 21, 42 and 63 mg/ mice, respectively, for seven weeks. Mice injected with 63 mg were the mostly affected and showed signs of acute cellular and physiological damage involving oligocythemia, leucoytosis, marked increase in serum urea, cholesterol, triglycerides, creatinine, Aspartate Aminotransferase (AST), alanine aminotransferase (ALT), hematocrit (HCT) and mean cell hemoglobin concentration (MCHC), while blood platelets showed abnormal increase which suggest an inhibitory action on haemopiesis. In addition, the abnormal pathophysiology observed here reflects the sever toxic effect from the crude extract of O. agardhii on both liver and kidney.

Key words: Cyanobacterium, Blood, Histopathology, Mice

Abbreviation: AST, Aminotransferase; ALT, alanine aminotransferase; HCT, hematocrit; MCHC, mean cell hemoglobin concentration; HPLC, high pressure liquid chromatography; i.p, intraperitoneally; FS, field stimulation; SPE, solid phase extraction; IST, international sorbent technology; RBC¢s, red blood cell; HB, hemoglobin; WBC¢s, white blood cell count