In vitro nematocidal activity of commercial fatty acids and β-sitosterol against Haemonchus contortus

Abstract

Haemonchus contortus is a haematophagous gastrointestinal nematode (GIN) that causes severe anaemia and even death in small ruminants, negatively impacting the economic viability of farms. Traditionally, this parasite has been controlled with chemical compounds; however, inadequate use of these types of products has favoured the emergence of anthelmintic resistance. Therefore, it is necessary to search for alternatives for GIN control. Previous studies have reported the anthelmintic activity of edible mushroom extracts against H. contortus. A recent study reported that a fraction constituted of different fatty acids and β-sitosterol isolated from the basidiomata of the edible mushroom Pleurotus djamor ECS-123 has ovicidal and larvicidal activity against H. contortus. Thus, this study aimed to assess the anthelmintic activity of the pure molecules: pentadecanoic acid, palmitic acid, β-sitosterol, stearic acid and linoleic acid. For this purpose, an egg-hatching inhibition test was carried out in which the compounds were evaluated individually and in combination at a final concentration of 20 mg mL−1. Furthermore, larval mortality was assessed using a combination of the five commercial compounds previously mentioned at different concentrations (1.25–20 mg mL−1). Palmitic acid and stearic acid, in some combinations, inhibited H. contortus egg hatching by 100%. On the other hand, in the larval mortality test, the combination of the five compounds showed dose-dependent behaviour, and 100% mortality was obtained 24 h post-incubation. Pure molecules and their combinations have anthelmintic-like activity against the eggs and larvae of H. contortus.

Bio-Guided Fractionation and Molecular Networking Reveal Fatty Acids to Be Principal Anti-Parasitic Compounds in Nordic Seaweeds

“…The PUFA linoleic acid has shown nematocidal activity against the nematode Caenorhabditis elegans ( Stadler et al, 1994 ; Panda et al, 2020 ), but also against H. contortus in vitro with a EC 90 of 0.93 mg/ml ( Ayers et al, 2010 ). One study found a mix of fatty acids (unsaturated and saturated) at concentrations >5.8 mg/ml showed high mortality (>90%) of H. contortus L3 in vitro ( Pineda-Alegría et al, 2020 ). Our study showed a high mortality (>90%) at concentrations of only 0.25 mg/ml for all our isolated compounds against A. suum and >90% mortality for all dual combinations at 0.13 mg/ml except one ( 2 + 3 (EC 20 )).…”

The Possible Biotechnological Use of Edible Mushroom Bioproducts for Controlling Plant and Animal Parasitic Nematodes

“…However, the combination of the two compounds showed hatching inhibition of 70 to 100%. On the other hand, in the larval mortality test, the combination of the five compounds showed 100% mortality at 20 mg/mL at 24 h. Thus, the activity found with the combination of molecules present in the edible fungi suggests synergistic activity [37].…”

“…The search for the potential use of the nematocidal compounds from different EM species has included a small number of studies using free-living nematodes [ 19 – 25 ] and some studies exploring the activity against parasitic nematodes of plants [ 17 , 20 , 22 , 26 – 29 ] under in vitro conditions. More recently, different EM materials began to be screened for their nematocidal activity against larval stages of ruminant parasitic nematodes [ 8 , 30 – 37 ]. The present review confirmed that the number of scientific studies on the nematocidal activity of EM is still small.…”

Nematicidal activity of leaf extract of Moringa oleifera Lam. against Haemonchus contortus and Nacobbus aberrans

“…A positive control, a commercial anthelmintic (ivermectin) at 5 mg/mL, was also used. The plates were incubated at 28°C for 12 h for N. aberrans and 48 h for H. contortus (Pineda-Alegría et al, 2020). At the end of the confrontation time, ten aliquots of 10 μL were taken from each well and placed on a slide, which was observed under an optical microscope.…”