Evaluation of Ovalbumin-Induced Asthma Protocols in Wistar Rats: A Comparative Study of Systemic Haematological, Oxidative, and Inflammatory Biomarkers

Abstract

Background: Ovalbumin (OVA)-induced asthma models are widely employed in experimental research; however, the extent to which different sensitisation and challenge protocols influence systemic biomarkers remains unclear. This study investigated the effects of varying OVA induction methods on haematological indices, oxidative stress markers, and inflammatory cytokines in Wistar rats.

Methods: This study involved 42 female Wistar rats weighing 140-180g, which were acclimatized for one week. They were divided into 6 different groups of 7 rats. During the experimental process, all groups (2-6) were sensitized with 1 mg OVA and 20 mg AlOH dissolved in 0.9% saline on days 1, 7, and 14, and then challenged with 1% OVA biweekly for 28 days. Group 1 control; group 2 sensitized on day 1 and 7, group 3 sensitized on day 1, 7, and 14; group 4 sensitized on day 1 and challenged; group 5 sensitized on day 1 and 7 and challenged; group 6 sensitized on day 1, 7, and 14 and challenged.  All animals were euthanized at the end of 28 days. Haematological parameters (white blood cell count, leukocyte differentials, platelet indices), oxidative stress markers (malondialdehyde [MDA], catalase, superoxide dismutase [SOD], glutathione peroxidase [GPx], total protein), and cytokines (IL-10, NF-κB, TNF-α) were quantified and compared with control animals.

Results: No statistically significant differences (p > 0.05) were observed in haematological parameters, SOD, GPx, total protein, IL-10, NF-κB, or TNF-α across groups (challenged and sensitized) compared to controls. However, rats sensitised on day 1 and challenged showed a significant increase in serum MDA and catalase activity (p < 0.05), indicating mild oxidative stress.

Conclusion: Different OVA sensitisation and challenge methods did not significantly alter systemic haematological or cytokine profiles in Wistar rats, although oxidative stress was evident under specific conditions. These findings suggest that commonly used OVA protocols may be insufficient to induce systemic features of asthma, and oxidative stress markers such as MDA and catalase may provide more sensitive indicators of early systemic alterations. Future studies should employ chronic exposure models and broader biomarker panels to enhance translational relevance.