Effects of enrofloxacin and ciprofloxacin hydrochloride on canine and equine chondrocytes in culture.

The research explored the toxic effects of two drugs, enrofloxacin and ciprofloxacin hydrochloride, on cartilage cells of dogs and horses. The study indicated that these drugs cause morphological changes and decreased ability of cartilage cells to adhere to substrates.

Methods and procedures

• The study involved cartilage cells (chondrocytes) derived from dogs aged between 4 and 6 months and horses aged between 2 and 4 years.
• The cells were cultured with four different concentrations of each drug, as well as in culture medium devoid of Magnesium (Mg2+).
• A live/dead test was implemented to study the cytotoxic effects of both drugs.
• Alterations in cell morphology were observed via electron microscopy.
• An attachment assay was performed to evaluate the ability of chondrocytes to stick to collagen type II coated-chamber slides in the presence of ciprofloxacin hydrochloride and under Mg2+-free conditions.

Results and findings

• Findings revealed that cartilage cells exposed to these drugs or grown in Mg2+-free medium showed a decrease in their adhesion abilities.
• Various changes including in the form and structure of the cellular skeleton made up of actin and vimentin proteins were observed to occur in a concentration-dependent manner under both treatment conditions.
• These effects were not specific to a particular species as similar changes were observed in both dogs and horses.
• On the first day of culturing, adhesion of cartilage cells to collagen type II was reduced to 70% in the ciprofloxacin hydrochloride treatment group and 45% in the Mg2+-free treatment group.
• On the fifth day of culture, the adhesion of the cartilage cells reduced further to 45% in the ciprofloxacin hydrochloride treatment group and 40% in the Mg2+-free treatment group.

Conclusion and implications

• The observed toxic effects of the two drugs on the chondrocytes were ascribed to irregular integrin signalling and the subsequent cellular changes. Integrins are receptors that mediate the attachment between a cell and the tissues surrounding it.
• This suggests that exposure to these drugs has significant potential to induce morphological changes in articular cartilage in living animals.
• This research increases our understanding of how these drugs might affect cartilage health, providing useful insights for their use in veterinary practices.