Phytochemical profiling and anthelmintic potential of extracts of selected tropical plants on parasites of fishes in Epe Lagoon

This research aims to study the anthelmintic properties of selected five (5) tropical plant extracts, ascertained margin of fish host safety in reference with praziquantel, a commonly used chemo-therapeutics. Qualitative and quantitative analysis of Alligator pepper seeds (Aframomum melegueta), Moringa leaves (Moringa oleifera), Neem leaves (Azadirachta indica), Ginger bulbs (Zingiber officinale) and Garlic (Allium sativum) and their potencies in reference to praziquantel against Clarias gariepinus and different classes of helminth parasites were investigated. The results obtained show that the 70% ethanol extract had 80 to 100% presence of the phytochemical content, compared with the 100% aqueous and 100% ethanol extracts with 50 to 80% and 50 to 90%, respectively. Among the five tropical plants, the richest in saponin and flavonoids are alligator pepper and neem with alkaloids, tannin, flavonoid and saponin in ratios 1:1:3:9 and 1:1:4:3 respectively. While, moringa, garlic and ginger are rich in alkaloids with alkaloids, tannin, flavonoid and saponin in ratios, 8:1:10:1, 6:2:1:4 and 6:3:2:1, respectively. Aframomum melegueta and praziquantel showed above 70% potency (at 96 h LC₅) against all the classes of parasites; Wenyonia spp (cestode), Procamallanus spp (nematode), Tenuisentis spp (acanthocephalan), and Electrotaenia sp (cestode) as compared to the other plant extracts that showed above 70% potency (at 96 h LC₅) only against Electrotaenia spp. Sub-lethal Concentrations (96 h LC₅) of praziquantel and Aframomum melegueta on the juvenile fish host (12.36 mg/l and 9.9 mg/l respectively) were found to be 90.9% and 93.5% effective against adult Electrotaenia spp after 8 to 10 min of exposure. These concentrations were 78 to 85.7% and 89.7 to 88.4%, respectively, effective against the other classes of parasites after 18 to 25 min and 15 to 21 min of exposure. These concentrations were tested on the post juvenile of the fish to determine behavioral changes; there were no significant behavioral responses after 24 h of exposure. The effective concentrations indicate the widest margin of safety for the fish host.