Abstract:
The potential toxic effect of Microcystis aeruginosa through oral
contamination is becoming important. The present study was carried out to
find the possible hepatotoxic effects of toxic M. aeruginosa (PCC 7820) on
male Wistar rats as animal model. Hepatotoxicity assessment 1vas done by
estimation of serum hepatic enzyme levels of r-Glutamyl transferase (GGT).
Alkaline phosphatase (ALP). Alanine aminotransferase (ALT/GPT), Aspartate
aminotransferese (GOT/AST). Rat treated with non toxic (CYA -/3) and
toxic non homogenized M. aeruginosa (PCC 7820) were normal in appearance
where as rats receiving homogenized toxic M aeruginosa (PCC 7820) were
lethargic and gained less weight which indicates a possible toxic effect on
the test animals. The absolute and relative (% body weight) mean weight of
liver and kidneys ofthe homogenous toxic M aeruginosa (PCC 7820) treated
animal lj'ere lower than those who received non homogenized toxic M
aeruginosa (PCC 7820) and the difference is statistically significant
(p<0. 00J). Liver sections of rats receiving fresh toxic M aeruginosa and the
homogenized toxic M aeruginosa did not show lymphatic infiltration or signs
of necrosis. Rats treated 'with homogenized M aeruginosa showed lowering
of absolute liver weight compared to the fresh M aeruginosa treated rats.
Statisticcally significant (p<0.005) increase levels of serum y-Glutamyl
transferase (GGT) was detected in rats 14 days after oral administration
with homogenized toxic M aeruginosa (PCC 7820). There was no significant
differentfound in serum Alanine aminotransferase (ALT/GPT) concentration
between treated and control groups. The results indicate that prolonged oral
administration of homogenized M. aeruginosa lead to functional
hepatotoxicity in male Wister rats without evident histopathological liver
necrosis.
