Abstract

Doxycycline (DOX) is one of widely used antibiotics for treatment of different diseases
in human and animals. This study aimed to evaluate the toxic effects of DOX on different
organs in rats. The experiment was carried out on forty albino rats, they were randomly
divided into four equal groups (10/each): Group 1 served as control group, Group 2 received
doxycycline hyclate 5 mg/Kg Bwt, Group 3 received doxycycline hyclate 25 mg/Kg Bwt and
Group 4 received doxycycline hyclate 50 mg/Kg Bwt. DOX was given intragastrically twice
daily (12 hours interval) for 4 weeks. The results revealed a significant increase in serum
level of liver enzymes (aspartate aminotransferase (AST), alanine aminotransferase (ALT),
alkaline phosphatase (ALP) and gamma-glutamyltransferase (GGT)), increased serum total
protein, albumin and globulins, elevated serum levels of urea and creatinine, in addition to
an increase in cardiac toxicity indicators (lactate dehydrogenase (LDH), and creatine kinase
(CK)-MB enzymes and troponin-I). Also, there were significant increase in levels of
malondialdehyde (MDA) and significant depletion of reduced glutathione (GSH) content
besides various histopathological alterations in liver, kidneys and heart of DOX treated
groups.

Key words: Key Words: Doxycycline, Toxicity, Oxidative stress, Histopathology