Preliminary Oncopharmacological Evaluation of Praxelis clematidea (Griseb): Growth Inhibition, Cytotoxicity, and Antioxidant Activities

Background and Objective: Praxelis clematidea (Griseb), an Asteraceae species often classified as an invasive weed, has recently gained research attention for its pharmacological potential. However, its oncopharmacological properties remain unexplored. This study aimed to evaluate the growth inhibitory, cytotoxic, and antioxidant activities of P. clematidea extracts and fractions to provide preliminary insights into its possible anticancer potential. Materials and Methods: Crude extract of P. clematidea was obtained using Soxhlet extraction (yield: 12.7%) and partitioned into chloroform (26%) and aqueous (61.6%) fractions. Growth inhibition was assessed on Sorghum bicolor radicles over 96 hrs, cytotoxicity on Raniceps ranninus tadpoles for 24 hrs, and antioxidant activity using the ABTS radical scavenging assay. Results were statistically analyzed, and dose response relationships were evaluated. Results: Radicle growth inhibition was both dose- and time-dependent, with nearly complete suppression at 30 mg/mL after 96 hrs. Radicle lengths were significantly reduced: Crude (0.2±0.0 cm), aqueous (0.767±0.067 cm), and chloroform (0.167±0.067 cm) compared with the control (10.667±0.318 cm). Cytotoxicity increased with concentration, with the crude and chloroform fractions causing 100% mortality at 20 mg/mL within three and 2 hrs, respectively, while the aqueous fraction showed only 13.33% mortality after 24 hrs. Antioxidant activity was strongest in the crude extract (82.52% inhibition; EC₅₀ = 150.04 μg/mL) and chloroform fraction (78.8%; EC₅₀ = 207.7 μg/mL), but weak in the aqueous fraction (11.48%; EC₅₀ = 2000 μg/mL). Conclusion: The findings suggest that P. clematidea contains moderately non-polar bioactive compounds responsible for its inhibitory, cytotoxic, and antioxidant effects. These preliminary results indicate promising oncopharmacological potential, supporting further isolation, structural characterization, and mechanistic studies of its active constituents.