In vitro and in vivo characterization of p-amino-phenethyl-m-trifluoromethylphenyl piperazine (PAPP), a novel serotonergic agonist with anthelmintic activity against Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus colubriformis

Abstract Loline, an alkaloid produced by Epichloë endophytes in pastoral grass species, is considered non-toxic with suggested antimicrobial and anthelmintic properties. In vivo metabolism of loline suggests ability to reach the abomasum or intestine, and anthelmintic benefit is indicated in vitro when parasites are in either a developmental stage close to the gastric mucus layers or adult stage consuming blood. Therefore, the objective of this project was to investigate the validation of using a loline seed extract as a natural anthelmintic in parasitized lambs. Sixteen Coopworth lambs were individually penned, offered ad-libitum lucerne pellets and water and randomly assigned to 3 treatment groups; CON; no treatment, or treatment with a Festuca pratensis seed extract with (LOL) or without loline (NIL). Lambs were orally infected with 20,0000 L3 Haemonchus contortus on day 0, and 10,000 L3 Teladorsagia circumcincta, and Trichostrongylus colubriformis on day 14. Parasites then matured to determine lolines efficacy on blood feeding adult Haemonchus contortus and L4 mucosal browsers Teladorsagia circumcincta, and Trichostrongylus colubriformis. Loline was orally dosed at 52.5 mg/kg LW starting on day 13, and every other day until slaughter for worm enumeration on day 28. Feed intake and refusals were recorded daily, and fecal samples were taken prior to infection, on loline dose days and at slaughter. Worm and fecal egg counts were transformed to log10 and all data were analyzed in Genstat (18th edition). Significance was declared at P < 0.05. Worm burdens of T. circumcincta (P = 0.96), T. colubriformis (P = 0.43), and H. contortus (P = 0.15) were not different between treatments. No treatment difference (P = 0.39) was observed in fecal egg counts, weight gain (P = 0.51), or feed intake (P = 0.18). Average growth efficiency (kg LWG/ kg DM intake) was 0.18 in CON which was less (P = 0.01) than LOL (0.24) or NIL (0.23). In conclusion, limited evidence supported an in vivo anti-parasitic effect of loline.

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In vitro action of Mimosa caesalpinifolia ketone extract on Haemonchus contortus and Trichostrongylus colubriformis

Semina Ciências Agrárias ◽

10.5433/1679-0359.2017v38n4p1963 ◽

2017 ◽

Vol 38 (4) ◽

pp. 1963 ◽

Cited By ~ 1

Author(s):

Danilo Rodrigues Barros Brito ◽

Livio Martins Costa Júnior ◽

João Luis Garcia ◽

Suzana Gomes Lopes ◽

Giselle Cutrim de Oliveira Santos ◽

...

Keyword(s):

Phenolic Compounds ◽

Haemonchus Contortus ◽

Anthelmintic Activity ◽

In Vivo Studies ◽

In Vitro Assays ◽

Trichostrongylus Colubriformis ◽

Lower Efficiency ◽

Egg Hatchability

This study aimed to evaluate the in vitro anthelmintic activity of Mimosa caesalpinifolia (sabiá) ketone extract, which is rich in condensed tannins (CT), on Haemonchus contortus and Trichostrongylus colubriformis. The leaves and stems of M. caesalpinifolia were collected, dried in the shade, and ground to a dry powder from which ketone extracts were obtained for in vitro assays. The extracts were diluted in 5% acetone and PBS to concentrations in the range 0.25-2.80 mg mL-¹ and the inhibition of egg hatchability was assayed. Feces collected from goats naturally infected with H. contortus (55%) and T. colubriformis (45%) were macerated and the helminth eggs were collected to conduct in vitro egg hatchability tests. Nematode larvae collected from the feces were used for a larval exsheathment inhibition assay of M. caesalpinifolia leaf and M. caesalpinifolia leaf and stem ketone extracts at concentrations of 0.6 and 1.2 mg mL-¹; three replicates were performed for each concentration. PBS was used as a negative control. Polyvinylpolypyrrolidone (PVPP) was added to the extracts to assess the effect of phenolic compounds on anthelmintic activity. An inhibitory effect of 80.7% and 82.3% was observed on hatchability after treatment with 1.0 and 2.0 mg mL-¹ M. caesalpinifolia leaf ketone extract, respectively. An inhibition rate lower than 75% was observed for 1.0 mg mL-¹ M. caesalpinifolia leaf and stem ketone extract. The M. caesalpinifolia leaf ketone extract larval exsheathment assay resulted in inhibition of 97.3% and 99.8% at concentrations of 0.6 and 1.2 mg mL-¹, respectively. For the leaf and stem ketone extract, the larval exsheathment inhibition was 94.3% at 1.2 mg mL-¹. The leaf and leaf and stem extracts showed no inhibitory effects on larval exsheathment after the addition of PVPP. These results showed that cuticular loss was related to the action of the phenolic compounds in the M. caesalpinifolia extracts. M. caesalpinifolia leaf ketone extract inhibited egg hatchability, but the leaf and stem extract showed lower efficiency, which indicated a greater abundance of active compounds in the leaves. The M. caesalpinifolia ketone extracts were effective in the inhibition of larval exsheathment at the highest concentration tested. Based on these results, in vivo studies should be performed to demonstrate the anthelmintic activity of this plant in goats.

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