Quantitative analyses of polyphenol extracts from inflorescences of Musa x paradisiaca against free-living stages of Haemonchus contortus

Extracts from Musa x paradisiaca inflorescences were chemically characterized and tested in vitro on ruminant parasite egg hatch (EHT) and larval migration (LMT) tests. The aqueous (EHW-I) and hydroalcoholic (EOH-I) extracts of the plant were analyzed by using colorimetric assays, high-performance liquid chromatography (HPLC), and electrospray tandem mass spectrometry (ESI-MS/MS). EHW-I and EOH-I had similar phenolic contents. However, EOH-I had a higher flavonoid content than EHW-I. Both extracts presented low contents of condensed tannins. HPLC analysis showed that EHW-I contained phenolic acids (chlorogenic acid ˃ coumaric acid > ferulic acid), other than rutin (glycosylated flavonoid). EOH-I contained rutin as the predominant compound. EHW-I and EOH-I showed an inhibitory effect on EHT, reaching almost 100% at a concentration of 1000 µg/mL. The inhibitory concentration of 50% (IC50) of egg hatching was 62.58 and 137.79 µg/mL of EHW-I and EOH-I, respectively. Based on the quantification data of phenolic and flavonoid compounds in the extracts, chlorogenic acid and rutin were selected for the EHT. Chlorogenic acid presented high activity, with an IC50 of 17.55 µg/mL. Rutin, however, did not affect egg hatching under the conditions tested. It can be inferred that chlorogenic acid may be a candidate with ovicidal activity. EHW-I and EOH-I did not affect the migration of third-stage nematode larvae, which may be related to the low tannin content. The inflorescences of Musa x paradisiaca can be further explored to develop a plant-derived anthelmintic product for ruminants and other animals.