Evaluation of serum and tissue biochemical assays of Rattus norvegicus after sub-acute oral administration of ethyl acetate sub-fraction of Spilanthes filicaulis

Abstract Background Plants medicinal potential is well established, yet unregulated use can lead to health risks without proper toxicological assessments. This study aimed to evaluate the sub-acute toxicity of the ethyl acetate sub-fraction of Spilanthes filicaulis (ESSF) in Rattus norvegicus . Methods Seventy-two male Wistar rats (148 ± 8.0 g) were randomly divided into groups. Group I (control) received 0.5 ml of distilled water, and Groups II–VI were administered ESSF orally at 62.5, 125, 250, 500, and 750 mg/kg body weight, respectively. Serum along with tissue (liver, kidney, and brain) biochemical assays were analysed after 14 and 28 days. Results The results showed no significant differences ( p > 0.05) in total protein, albumin, serum electrolytes, creatinine, urea, or total and conjugated bilirubin between treatment and control groups. However, minor elevations were noted in some biomarkers at specific doses after 14 and 28 days of treatment, though these remained within normal physiological ranges. A significant increase in serum glutamate dehydrogenase (GDH) was observed after 14 days in treated groups compared to controls ( p < 0.05), but this were normalised by day 28, suggesting a reversible effect. Alkaline phosphatase (ALP), GDH, and creatinine kinase (CK) activities in tissues showed no significant differences between treated and control groups after 28 days of treatment, indicating no long-term tissue damage. Conclusions These findings suggest that sub-acute oral administration of ESSF does not induce significant biochemical abnormalities. This implies that ESSF is relatively safe at the tested doses and supports its potential for therapeutic development. However, further long-term studies are necessary to establish its safety profile fully.