Use of tanninipherous plants extracts to inhibit hatchability of eggs of Haemonchus contortus in vitro test

A sustainable alternative to combat the gastrointestinal nematodes in sheep are tanninipherous plants, because of the use of anthelmintics on the market is exacerbated, nematodes developed resistance. The aim of this work was to evaluate the tanninipherous plants extracts on eggs hatch assay (EHA) of Haemonchus contortus. The work was conducted at the Institute of Animal Science (IZ/APTA/SAA) Nova Odessa/São Paulo/Brazil. The leaves of the following Fabaceae Mimosa caesalpineafolia, Arachis pintoi cv. amarillo, Gliricidia sepium, Neonotonia wightii cv. cianova and Stizolobium aterrium were collected at agrostological field of the IZ/APTA/SAA, dried at 35 ° C and ground. Their actives ingredients were extracted with a solution of acetone:water (70:30), followed by dichloromethane and freeze-dried. The values of total tannins (TT) and condensed tannins (CT) were calculated by methodology of Makkar et al. [1]. The values found for TT and CT are shown in Table 1. The lyophilized extract was soluble in water at concentrations ranging from 50 mg/mL to 0.012 mg/mL to perform EHA. Data were analyzed by SAS/Probit to determine Lethal Concentration 50 (LC50) with independent variables (dose) transformed by natural logarithms (log-dose). The lowest LC50 was found for M. caesalpineafolia of 0.53 mg/mL, followed by A. pintoi (4.9 mg/mL), G. sepium (32.9 mg/mL), N. wightii cv.cianova (42.8 mg/mL) and S. aterrium, concentration was not able to inhibit eggs to hacth. Among the plants evaluated the M. caesalpineafolia proved to be the most effective in inhibiting the hatchability of the eggs of H. contortus also its correlation with tannins.

Tab. 1: Values found for TT and CT.

Plants	M. caesalpineafolia	S. aterrium	A. pintoi	G. sepium	N. wightii (cianova)
TT*	108.70	39.78	32.84	17.71	11.19
CT**	100.85	48.95	59.47	2.01	0.30
TT: Total Tannins; CT: Condensed Tannins, *expressed values: g of tannic acid/kg DM, **expressed values: g of leucocyanidin/kg DM

Acknowledgements: FAPESP (2012/18379 – 3) and CNPq (476880/2012 – 2)

Keywords: Extracts, Leguminosae, nematodes, sheep, tannins

References:

[1] Makkar, H.P.S.; Blummel M.; Borowy, N.K.; Becker, K. Gravimetric determination of tannins and their correlation with chemical and protein precipitation methods. Journal of the Science of Food and Agriculture. v.61, p. 161 – 165. 1993.