ANTIALLERGIC EFFECT OF AQUEOUS EXTRACT OF VERNONIA AMGYDALINA IN OVALBUMIN-INDUCED ALLERGIC RHINITIS WISTAR RATS

Abstract

Allergic rhinitis is a chronic IgE-mediated inflammatory condition of the nasal mucosa that significantly affects quality of life worldwide. This study evaluated the antiallergic effect of aqueous leaf extract of Vernonia amygdalina on serum immunoglobulin E (IgE) levels in ovalbumin-induced allergic rhinitis Wistar rats. Twenty-five adult Wistar rats were randomly assigned into five groups: normal control, positive control (loratadine-treated), and three extract-treated groups receiving 200, 400, and 600 mg/kg body weight of V. amygdalina extract. Allergic rhinitis was induced using intraperitoneal sensitization with ovalbumin and aluminum hydroxide followed by intranasal ovalbumin challenge. Serum IgE levels were quantified using enzyme-linked immunosorbent assay (ELISA), and data were analyzed using one-way ANOVA with Tukey’s post-hoc test. The results showed a significant increase in serum IgE levels in ovalbumin-sensitized rats compared with the normal control group (p < 0.05). Treatment with aqueous V. amygdalina extract at 200 mg/kg resulted in a further significant elevation of IgE levels, while higher doses (400 mg/kg and 600 mg/kg) produced slight reductions that were not statistically significant when compared with control groups. In contrast, the loratadine-treated group demonstrated IgE levels comparable to the normal control. In conclusion, aqueous leaf extract of Vernonia amygdalina did not exhibit significant antiallergic activity in terms of serum IgE suppression in ovalbumin-induced allergic rhinitis Wistar rats under the conditions of this study. The extract may exert immunostimulatory rather than antiallergic effects.