Toxicological evaluation of the leaves of Guiera senegalensis (J.F. Gme), Cassia occidentalis (Linn), and Ziziphus mauritiana (Lam)

Abstract Background There is a renewed global interest in plant-based medicine in the last few decades as a result of affordability and efficacy of the form of medicine. However, the safety of many medicinal plants and plant preparations has not been determined. To this end, this study determined the safety of the methanol extracts of the leaves of Guiera senegalensis, Cassia occidentalis, and Ziziphus mauritiana, which are plants commonly used in plant medicine in Africa. Results Phytochemistry of the plants’ extracts showed alkaloids were the most abundant phytochemical in the extracts, followed by tannins, saponins, flavonoids, and glycosides, respectively. All the rats behaved normally at doses up to 2000 mg kg−1, while at 3000 mg kg−1, rats in C. occidentalis group developed breathing problems. At 5000 mg kg−1, C. occidentalis group showed convulsion, whereas Z. mauritiana and G. senegalensis rats displayed temporary weakness. After 60-day dosing, significant differences (p < 0.05) were observed in the liver enzymes (ALP, AST, ALT, TP, and ALB) of most of the test rats compared with the control. Kidney function test showed the Na+, K+, Cl−, urea, and creatinine of the test rats were reduced compared with the control, but only significant (p < 0.05) in a few of the parameters. Fatty metamorphosis, lymphocytic infiltration, and karyorrhexis were observed in the liver tissues of the treated rats, but not in the control. Conclusion These results show the plants are nontoxic at moderate doses, but could be injurious at high doses or if taken repeatedly for an extended period.