Asparagus horridus spirostanol saponins and their antischistosomal and antinociceptive potential: evidence from in vivo and in silico research

Two novel spirostane saponins, Asparanin (A), (25 R)-6α-[(β-D-glucopyranosyl)oxy]-5α-23α-hydroxy-spirostane-3β-yl-β-D-galactopyranoside and Asparanin (B), (25 R)-6α-[(β-D-galactopyranosyl) oxy]-27-hydroxy-5α-spirostane-3β-yl-β-D-galactopyranoside, besides three compounds: (25 R)-6α-[(β-D-glucopyranosyl)oxy]-5α-spirostane-3β-yl-β-D-galactopyranoside (3), (25 R)-5α-spirostane-3β-yl O-β-D-glucopyranosyl-(1→2)-O-β-D-glucopyranoside (4), and apigenin 8-C-glucoside (Vitexin) (5) were found in Asparagus horridus. N-butanol extract and its steroidal saponins (1-4) were tested for their antischistosomal and antinociceptive activities. The antischistosomal activity of the steroidal saponins 1 and 3 reported here is significant. Compound 3 at 100 mg/kg decreased the total number of Schistosoma mansoni worms by 20.41% and the total number of coupled worms by 4.40%. A molecular docking study showed that compound 3 interacts with key residues in the active site of the Thioredoxin glutathione reductase enzyme from S. mansoni, yielding a high-energy score of −10.42 Kcal/mol. Antinociceptive activity was determined using the acetic acid-induced writhing, the hot plate, and tail immersion tests. Compounds 2-4 showed significant antinociceptive activity, with compound 2 exhibiting the highest analgesic activity, followed by compound 3, and then compound 4.