INTRODUCTION
The production of small ruminants in most semi-arid areas of Mexico is mainly due to the poor sanitary situation of the animals and the parasitism due to the gastro-intestinal strongyles having an important role in the health of the sheep (1). Oesophagostomum columbianum Curtice, 1890, caused different damages to the small ruminants (2,3). They have been the most important nematodes in the sheep in the region of Huichapan, Mexico (4,5).
The anthelmintic effect of some plant products has been published in different countries (6,7,8). The tropical plant Bromelia pinguin has been used as an anthelminth and it has been successful on Haemonchus contortus in Cuba (9).
The objective of the present work was to know the anthelmintic effect of the fruits and the extract of the plant Bromelia pinguin on Oesophagostomum columbianum in sheep.
MATERIALS AND METHODS
Materials
The fruits of the plant were collected and the pulp was separated from the peel. The pulp has been used naturally as an aqueous extract. The fruit extract has been obtained according to the methodology described by Marrero et al. (9).
Parasitological and monitoring methods
Sheep were experimentally infected with 500 infective larvae of O. columbianum.
Up to 40 days, the animals were followed by a quantitative coproscopy. The number of eggs per gram of faeces (EPG) was determined, and in this way homogeneous pilot batches were constituted.
After the treatment, the quantitative coproscopy was carried out at 24 and 48 h. All along of the research, the animals were fed artificial grazings and received a food suplement.
EPG were quantified according to the of McMaster egg counting technique with a solution of Na Cl (density 1.2) to determine the effect of the treatments. At the 25th day after treatment, two sheep of every group were slaughtered to observe the presence of the parasites.
Experimental device and treatments
The research was performed in the farm of the Universidad Nacional Autónoma, Xochimilco, in Mexico City, using 50 Creole sheep of 6 months of age belonging to the region Huichapan, all of them parasitized by O. columbianum.
Five groups of ten sheep each were conformed, managing the treatments in the different groups:
The untreated control group (Group 1)
The control group treated with ivermectin (Ivomec, MSD ND) at a dose of 0.2 mg/kg (Group 2)
The group treated with B. pinguin extract at a dose of 500 mg per animal (Group 3)
The group treated with B. pinguin fruits at a dose of 10 fruits per animal (Group 4)
The group treated with B. pinguin fruits at a dose of 15 fruits per animal (Group 5)
Analysis and calculation of the reduction percentage of EPG
The results were analyzed according to the method described by Ruiz-Ruiz et al. (10) which allowed determining the reduction of EPG using the following formulae:
N
-averages of EPG to the nc day before the treatment.
n
-averages of EPG to the ncday after the treatment.
Variance analyses were used to compare EPG averages.
The results are shown in the Table 1. The elimination of the helminth eggs in the control group was constant all along the research. Ivermectin showed efficacy against O. columbianum at 100% from 48 h. A strong efficiency (100%) with B. pinguin extract and fruits was also observed 48 h post treatment. The results of the share 5, dealt with 15 fruits of the plant, were at the height of the forecasting. At this dose, a strong efficiency (90.4 p 100) was observed on the 25th day. EPG reduction varied in each treated group, from 48 h after the administration of the plant products.
Table 1.
Average reduction of Oesophagostomum columbianum eggs (% EPG) before and after the treatments with Bromelia pinguin fruits and extract / Reducción de la media de huevecillos de Oesophagostomun columbianum (% hpg) antes y después de los tratamientos con las frutas y el extracto de Bromelia pinguin.
Group1 and Group 2: Control group
*Groups treated with B. pinguin
No helminths were observed in sheep of Group 2. Groups 3, 4 and 5 only showed some adults (3 to 5) of the studied group, compared to the control group. The number O. columbianum adults observed in the control group ranged from 20 to 27.
The development of egg excretion in the days following the treatment and the results obtained among the slaughtered animals, where the elimination of a big part of the O. columbianum population was evident, indicated a good anthelmintic efficacy of B. pinguin products. Marrero et al (9) also found that treatments with plant products affected the excretion of H. contortus eggs and had an anthelmintic effect, even in adults.
According to Ruiz-Ruiz et al. (10), B. pinguin is a natural source of bioactive compounds with proven antibacterial action against Echerichia. coli and Staphylococcus aureus that could be related to the presence of enzymes, protease inhibitors, and peptides.
The anthelmintic activity of B. pinguin could be explained by the presence of pinguinin, a proteolytic enzyme with antiparasitic activity according to Montes et al. (11). The mechanisms of action of this enzyme could be explained by its intervention in the inhibition of some metabolism phases, ATP production which causes the death of adult helminths, or by the intervention of the enzyme in the synthesis of proteins in the process of egg formation that helps to reduce EPG.
According to Nfi et al. (12), the antiparasitic inefficiency of some plant products in ruminants could be explained by the constant ingestion of infectious larvae found in the grass that maintains a level of parasite inside the host. In the case of O. columbianum, there is another important element regarding the strongyle having a biologic cycle with an internal larval phase in the intestinal mucous membrane, which can enter in hypobiostation to persist for a long time under these conditions, without being affected by the antiparasitic product. Under this condition, the parasite continues the elimination of eggs. These biological characteristics hinder the success of chemical and herbal medicine.
In this study it is evident that B. pinguin could be used in the treatment of O. Columbianum at the dose of 15 fruits per animal, hense it is necessary to continue the study of the purification of the plant extract and its evaluation as antihelminth.