HPLC-UV-ESI-TOF-MS Characterization of Bioactive Secondary Metabolites from Chromolaena odorata Extracts and Their Cytotoxicity, Cercaricidal, Antioxidant and Anti-inflammatory Activities In Vitro

Introduction: Schistosomiasis, a parasitic disease transmitted through freshwater snails, affects over 251.4 million people globally, with sub-Saharan Africa accounting for 95% of the disease burden. Despite the widespread use of praziquantel for mass drug administration, eradication remains elusive. Plants of the Asteraceae family have shown promising activity against helminths, including Schistosoma mansoni. This underscores the importance of further investigating this family's biological potential.

Methods: This study evaluates the phytochemical composition and characterizes the bioactive secondary metabolites, including antioxidant, anti-inflammatory, and cercaricidal properties, as well as the biosafety of the methanolic and hexane extracts of Chromolaena odorata.

Results: Preliminary phytochemical screening of Chromolaena odorata extracts identified secondary metabolites such as tannins, flavonoids, and saponins in the methanolic extract, and steroids and alkaloids in the hexane extract. LC-MS and HPLC-UV-ESI-TOF-MS analyses of the methanolic extract confirmed the presence of polyphenols (flavonoids) and aromatic dicarboxylic acid compounds. Antioxidant analysis revealed a strong free-radical scavenging potential in C. odorata crude extracts. Methanolic and hexane extracts of Chromolaena odorata demonstrated potent cercaricidal activity against Schistosoma mansoni cercariae, with LC₅₀ values as low as 0.2012 and 0.2410 µg/ml, respectively. The anti-inflammatory effects were assessed by inhibiting heat-induced albumin denaturation; plant extracts inhibited denaturation, particularly the methanolic extract, which showed 73.56% inhibition at the highest concentration tested. Cytotoxicity assays on LLC-MK2 cells showed low toxicity.

Conclusion: These findings suggest that crude extracts of Chromolaena odorata possess significant antischistosomal (cercaricidal), antioxidant, and anti-inflammatory properties, supporting their potential integration into primary healthcare strategies for schistosomiasis control.