Cytotoxic, phytotoxic and insecticidal assessment of the crude extract and fractions of leaves of Conyza sumatrensis (Retz.) E. Walker Asteraceae.

Résumé

This work focused on investigating the cytotoxic, phytotoxic and as well as the insecticidal activities of the extract and fractions of Conyza sumatrensis. The solvent-solvent partitioning of the extract obtained by cold maceration gave two fractions (aqueous and dichoromethane fractions) which were screened phytochemically along with the extract. The cytotoxic potential was evaluated using brine shrimp (10-1000 ìg/mL) and tadpole mortality assays (20-400 ìg/mL), while the phytotoxicity was done using Lemna minor frond (10-1000 ìg/mL) and Sorghum bicolor radicle (1-30 mg/mL) inhibition assays as well as insect contact assay for insecticidal activity. While the DCM-fraction recorded 100 % mortalities on brine shrimp and tadpoles at the maximum concentrations (1000 and 400 ìg/mL) it also recorded higher insecticidal activity of 80.62 % on Rhyzopertha dominica. However, the aqueous fraction was observed to give a higher phytotoxic activity as it gave complete inhibition at 20 and 30 mg/mL as well as 100 and 1000 ìg/mL against the radicle of Sorghum bicolor and fronds of Lemna minor respectively. The DCM and aqueous fractions of the plant have expressed higher cytotoxic, phytotoxic and insecticidal activities over the crude extract, which is an indication of potent cytotoxic, phytotoxic and insecticidal compounds which require further investigation.