Unveiling the Safety Margin: Acute Toxicity Assessment and LD₅₀ Determination of Senna occidentalis Extract in Wistar Rats

Abstract

Background: Senna occidentalis is used as a medicinal plant in several parts of Africa, Asia, and the Americas. Its seeds, leaves, roots, and stems have been used as laxatives, analgesics, diuretics, antibiotics, antidiabetic, hepatoprotective, antihyperlipidaemic, antioxidant, and antianaemic agents, and in the treatment of malaria, influenza, and liver and urinary tract infections. Aim: This study assessed the acute oral toxicity and median lethal dose (LD₅₀) of ethanolic leaf, stem, and root extracts of S. occidentalis in female Wistar rats. Materials and Methods: Twelve nulliparous, non-pregnant female Wistar rats aged 8–12 weeks were randomly assigned to four groups (n = 3 per group). Group 1 (control) received distilled water, whereas Groups 2, 3, and 4 received 2,000 mg/kg of S. occidentalis leaf, stem, and root extracts, respectively, by oral administration. The rats were observed for signs of toxicity, general behaviour, and mortality for 14 days. At the end of the experiment, the rats were euthanised, and the liver, kidneys, and heart were harvested for examination. Results: S. occidentalis produced no signs of toxicity or mortality during the study period; however, the leaf and stem extracts significantly (p < 0.05) reduced body weight. None of the extracts significantly affected the weights of the liver, kidneys, or heart. Phytochemical screening revealed alkaloids, cardiac glycosides, phenols, tannins, flavonoids, and saponins in all extracts. Steroids and terpenoids were detected in the root and stem extracts, anthraquinones and glycosides in the root extract, and polyphenols in the stem extract. The LD₅₀ values of the S. occidentalis leaf, stem, and root extracts were greater than 2,000 mg/kg. Conclusion: A single oral dose of 2,000 mg/kg of S. occidentalis leaf, stem, and root extracts caused no mortality or visible acute toxicity and did not significantly alter liver, kidney, or heart weights in female Wistar rats. Nevertheless, further biochemical, haematological, neurobehavioural, gross pathological, and histological assessments are required.