Toxicity Assessment of Vachellia karro (Hayne) Banfi and Galasso Pods using Brine Shrimp Assay

Background and Objective: Vachellia karroo is widely used in folk medicine in the Eastern Cape Province South Africa, however, the pods are usually discarded as waste. This study evaluated the toxicity of acetone, hexane, aqueous and methanol extracts of Vachellia karroo pods using brine shrimp model. Materials and Methods: Different concentrations (0.0625-1 mg/mL) of the extracts were used to incubate the cysts and nauplii of brine shrimp (Artemia salina) to evaluate their effects on the hatching of the cyst and mortality of the nauplii respectively. The percentage of hatched cysts and Lethal Concentration (LC₅₀) needed to kill 50% of the nauplii were recorded. Results: Successful hatching of the cysts was in order: Aqueous extract> methanol extract> hexane extract> acetone extract. The hatching of nauplii was in a concentration dependent fashion, with hatching success decreasing with increase in concentration of extracts. Conclusion: Lethality of extracts determined based on Meyers’ index of toxicity, revealed that acetone and hexane extracts of V. karroo were moderately toxic.