In Vitro Anthelmintic Activity of Sea Buckthorn (Hippophae rhamnoides) Berry Juice against Gastrointestinal Nematodes of Small Ruminants

Abstract

Gastrointestinal nematodes are one of the major threats in small ruminant breeding. Their control is difficult due to the development of anthelmintic resistance, and the search for new molecules endowed with anthelmintic activity (AH) is considered a priority. In this context, we evaluated the in vitro AH activity of two commercial sea buckthorn (Hippophae rhamnoides) berry juices, namely SBT and SBF. The in vitro evaluation was based on the egg-hatch test and larval exsheathment assay at different concentrations. Data were statistically analysed, and the EC₅₀ was calculated. Chemical analyses were performed to evaluate the total polyphenol content of the juices and chemical profile of the most represented compounds. The role of the polyphenolic fraction in the anthelmintic activity of the juices was also assessed. At the highest concentrations, the activity of SBT was high in both tests and comparable to that observed in the thiabendazole-treated positive controls, while SBF showed a lower efficacy. Glycosylated isorhamnetin and quercetin were the most represented polyphenolic compounds in both juices. In conclusion, both H. rhamnoides berry juices tested in this study showed interesting anthelmintic properties in vitro.

Keywords: Hippophae rhamnoides; anthelmintic activity; gastrointestinal nematodes; isorhamnetin; polyphenolic compounds; quercetin; sheep.

Figure 1

Structure of compounds gallocatechin 1, epicatechin 2, rutin 3, isorhamnetin-3-O-glucoside 4, myricetin 5, quercetin 6, isorhamnetin 7, and kaempferol 8.

Figure 2

HPLC chromatogram of sea buckthorn juice from Tuscany (a) and from Friuli-Venezia Giulia (b) at 360 nm. Peak 1 had a mass spectrum with a base peak of 787.2327 m/z and a secondary peak of 463.1246 m/z. Peak 2 had a mass spectrum with a single peak of 625.1782 m/z. Peak 3 had a mass spectrum with a base peak of 303.0511 m/z and a secondary peak of 465.1051 m/z. Peak 4 had a mass spectrum with a base peak of 625.1776 m/z and two secondary peaks of 479.1198 m/z and 317.0654 m/z. Peak 5 had a mass spectrum with a base peak of 317.0646 m/z and two secondary peaks of 479.1191 (M + H) and 501.1024 (M + Na).

Figure 3

Structure of compounds isorhamnetin-3-O-sophoroside-7-rha 9, isorhamnetin-3-O-glu-7-rha 10, isorhamentin-3-O-rutinoside 11, isorhamentin-3-O-neohesperoside 12, quercetin-3-O-galactoside 13, and quercetin-3-O-glucoside 14.

Figure 4

Concentration–response curves of GIN egg-hatch inhibition percentages caused by the sea buckthorn juices from Tuscany, Italy (SBT) and Friuli-Venezia Giulia, Italy (SBF).

Figure 5

Concentration–response curves of the GIN larval-exsheathment inhibition caused by the sea buckthorn juice from Tuscany, Italy (SBT), and Friuli-Venezia Giulia, Italy (SBF). PBS: phosphate-buffered saline.

Figure 6

Graphical representation of the larval-exsheathment inhibition percentages caused after 0, 20, 40 and 60 min by the two sea buckthorn berry juices examined in this study (SBT and SBF) at a concentration of 1200 µg/mL, and with and without the addition of polyvinylpolypyrrolidone (PVPP). (a) Sea buckthorn from Tuscany, Italy (SBT); (b) sea buckthorn from Friuli-Venezia Giulia, Italy (SBF).