Evaluation of Sub-acute and Sub Chronic Toxicity Profile of the Aqueous Leaf Crude Extract of Melanthera Scandens (Schumach & Thonn) in Wistar Rats

Aims: Although Melanthera scandens is a plant widely used in traditional medicine for the management of seizures, stomach ulcers and sores, dysmenorrhea, diabetes and malaria, there was scanty information about its safety. There was, therefore, a need to evaluate the sub-acute and subchronic toxicity studies of this plant which would reflect on its safety.

Methodology: This was an experimental laboratory study. The research was conducted at Kampala International University-Western Campus at the Pharmacology laboratory from February to June 2017. The sub-acute toxicity was evaluated after administering daily oral doses of M. scandens crude extract (250, 500 and 1000 mg/kg) for 28 days and 90 days for subchronic study, after which the effect on haematological, biochemical and histopathological parameters were assessed in male and female Wistar rats (five of each sex).

Results: Sub-acute toxicity results revealed that there was a significant decrease in the AST between the male Wistar rats that received 250 mg/kg (P= .005) and those that received 500 mg/kg (P= .05) as compared with the control group. Subchronic studies showed a significant increase in ALP (P= .05) at 1000 mg/kg compared with 500 mg/kg. Terminal necropsy did not reveal any treatment-related histopathological findings. There were also no toxicologically significant treatment-related effects on haematological parameters. The sub-acute toxicity results suggest that doses of 250mg/kg and 500mg/kg are safe and could be hepatoprotective due to reduced levels of AST and ALP, while the subchronic toxicity study results suggest that doses greater than 1000 mg/kg could be toxic to the plasma membrane, liver cells or endoplasmic reticulum due to increased ALP levels at this dose.

Conclusion: The M. scandens crude extract did not cause significant toxicity on haematological and histopathological indices, after sub-acute and subchronic administration in Wistar rats.