Safety Evaluation of Sub-acute and Acute Oral Treatment with Aqueous Extract and Methanol Fraction of Aloe barbadensis (Aloe vera) Leaves in Wistar Rats

Ethnobotanicals continue to gain global relevance due to their therapeutic potential and their role as precursors in pharmaceutical development. Aloe barbadensis is one of the most common traditional herbs in Nigeria, particularly for its purported antimalarial properties. The increasing use of traditional remedies in malaria-endemic regions like Nigeria makes it imperative to conduct regular safety assessments of medicinal plants. This study investigates the safety of A. barbadensis by assessing its acute and subacute toxicity. The plant was collected from Oke-Aluko farm in Ilorin, Nigeria, and authenticated by a botanical expert. Both aqueous extract and a methanol fraction of A. barbadensis leaves were prepared for the study. Wistar rats were administered single oral doses of 2000, 5000, and 6000 mg/kg, followed by a 14-day observation period to assess acute toxicity and potential delayed effects. For the subacute toxicity testing, daily doses of 250, 500, and 750 mg/kg were administered over 28 days. The liver functions (AST, ALT, ALP, GGT), kidney functions (urea, creatinine, sodium, potassium), haematological parameters, and histological analyses of the organs were evaluated. Results showed no significant adverse effects on biochemical or haematological parameters (p > 0.05) at all doses in both study phases. However, continuous treatment with the methanol fraction at 750 mg/kg led to histopathological changes in the liver and kidney after 28 days, indicating potential organ toxicity at higher doses. This study advocates for the extract dose regulation and future long-term chronic toxicity studies on the plant.