Effect of polyphenols extracted from Punica granatum and Acacia saligna plants on glutathione S-transferase of the cattle tick Rhipicephalus ( Boophilus ) annulatus (Acari: Ixodidae)

The objective of this study was to evaluate the effects ofPunica granatum red peel andAcacia saligna leaf extracts onRhipicephalus(Boophilus) annulatus GST activity in order to reduce the resistance of cattle to acaricide. The results showed thatP. granatum ethanol extract (70%) contained the highest total phenol content (350  ± 1.2 μM GAE g−1), the highest condensed tannin content (270  ± 1.3 μM CE g−1) and the highest hydrolysable tannin content (70  ± 5.0 μM TAE g−1). Adult immersion test with a dosage of 100  mg ml−1 ofA. saligna ethanol extracts had a significant mortality of 50% and 75% after 24  h and 96 h, respectively (p <  0.01). A simple and reproducible procedure was established to purify the wholeR. annulatus GST (wRaGST) while a full-length cDNA of GST was cloned from a cDNA library of the local Egyptian cattle tickR. (B.) annulatus (rRaGST). Aqueous extracts ofP. granatum inhibited both wRaGST and rRaGST with values of IC50 = 0.114 and 0.07 µg ml−1, respectively, compared toA. saligna extracts (IC50 values  = 2.08 and 1.35 µg ml, respectively). These inhibitory effects were attributed to the presence of a high tannin concentration (≥ 80%). HPLC analysis indicated the presence of gallic acid and catechin in both extracts, in addition to the rutin, which was only observed inA. saligna extracts. The addition of a tannin inhibitor, polyethylene glycol, suggested the existence of other phenolic compounds in ...
Source: Journal of Parasitic Diseases - Category: Parasitology Source Type: research