Preliminary Phytochemical Screening and Toxic Effect of Melanthera scandens Leaf Extracts Using Brine Shrimp (Artemia salina) Test

Aim: The aim of the study was to evaluate the toxicity of the crude extracts of Melanthera scandens leaves extracts using Brine Shrimp (Artemia salina) test in order to substantiate the ethnopharmacological uses of this plant in the treatment of different illnesses.

Methodology: Extractions of the dried powdered leaves of Melanthera scandens by maceration was carried out using ethanol and distilled water. All the extracts were subjected to preliminary phytochemical screening using standard methods while the toxicity of the extracts was evaluated using Brine Shrimp lethality assay. The percentage lethality (mortality) of the brine shrimp were evaluated in six different concentrations; 1000, 500, 250, 125, 62.5 and 31.25 µg/ml and the lethal concentration LC50 for 50% mortality of brine shrimp after 24 h of exposure to the extracts was determined.

Results: The preliminary phytochemical analysis showed the presence of saponins and cardiac glycosides in both extracts. However, tannins and flavonoids were present in the aqueous extracts while phlobatanins and terpenes/steroids were detected in the ethanol extract. The Brine Shrimp lethality assay revealed that ethanol and aqueous extracts were effective against brine shrimp nauplii with LC50 of 173.78 µg/ml and 331.13 µg/ml respectively. It was also observed that maximum mortalities took place at a concentration of 1000 μg/ml whereas least mortalities were at 31.25 μg/ml concentration.

Conclusion: Results of the phytochemical screening indicated that bioactive phytoconstituents were present in this plant and that the ethanol extract showed better toxicity against brine shrimp with LC50 value 173.78 µg/ml when compared to aqueous extract with LC50 value of 331.13 µg/ml. As a result of this, ethanol extract may be considered significantly active and have the potential for further investigation.