In vitro ovicidal and larvicidal activities of some saponins and flavonoids against parasitic nematodes of goats

This study assessed the anthelmintic activity of plant-derived compounds against gastrointestinal nematodes of goats using the egg hatch and larval motility assays. The compounds tested were saponins (digitonin and aescin) and their respective sapogenins (aglycones), hecogenin acetate and flavonoids (catechin, hesperidin, isocordoin and a mixture of isocordoin and cordoin). Additionally, cytotoxicity of active substances was analysed on Vero cell through 3-4,5-dimethylthiazol-2-yl,2,5diphenyltetrazolium bromide (MTT) and propidium iodide (PI) tests. Significant reduction on the egg hatching (P < 0.05) was seen only in the treatments with aescin (99%/EC50 = 0.67 mg mL−1) and digitonin (45%). The compounds that reduced the larval motility (P < 0.05) were digitonin (EC50 = 0.03 mg mL−1 and EC90 = 0.49 mg mL−1) and the hecogenin acetate (75%). The other sapogenins showed low anthelmintic activity. All the flavonoids showed low ovicidal (4–12%) and larvicidal (10–19%) effects. The aescin and digitonin showed low toxicity in PI test (viable cells >90%). Nevertheless, higher cytotoxicity was observed in the MTT assay, with IC50 of 0.20 mg mL−1 (aescin) and 0.0074 mg mL−1 (digitonin). Aescin and digitonin have a pronounced in vitro anthelmintic effect and the glycone portion of these saponins plays an important role in this activity.

(3β,5α,25R)-12-(Hydroxyimino)spirostan-3-yl acetate

The title steroid, C29H45NO5, obtained by condensation of hecogenin acetate [systematic name: (3β,5α,25R)-12-oxospirostan-3-yl acetate] with NH2OH, has the oxime group substituting the C-12 site on theCring of the steroid nucleus. The introduction of this functional group allows the formation of chain motifs, using the oxime OH group as a donor and the O atom of theEring as an acceptor. TheC(8) chains formed by this intermolecular hydrogen bond are oriented parallel to the short cell axisa. The structural features of this compound are very close to those of C29H43NO5, the derivative with a C14=C15 double bond in theDring, which crystallizes in the same space group and with similar unit-cell parameters.