In vivo anthelmintic activity of Phytolacca icosandra against Haemonchus contortus in goats.

The in vivo anthelmintic (AH) activity of the ethanolic extract from leaves of Phytolacca icosandra was evaluated in goats artificially infected with Haemonchus contortus. Parasite naïve goats were artificially infected with 3000 H. contortus infective larvae per animal. Once the infection was patent (day 28 post-infection) all the animals were sampled to determine the faecal egg counts (FEC) for five consecutive days. Two groups of animals were formed balanced for their FEC and body-weight (BW) (n=6/group): the non-treated control group and the treated group in which goats were individually administered with the ethanolic extract of P. icosandra. The extract was administered orally using gelatin capsules (250 mg/kg BW) which were dosed on two consecutive days using a pill-dispenser. Faecal samples were collected from each animal from the day of dosage (Day 0) on a daily basis to determine the number of eggs per gram of feces (EPG) for 15 days post-treatment (PT). The FEC of the two groups were compared using the repeated measures analyses of variance using the log transformed data Ln (FEC+1). The presence of saponins, coumarins, flavonoids, steroids and terpenoids were detected by standard methodologies in the extract. The P. icosandra ethanolic extract was further analyzed by gas chromatography (GC) coupled to a mass spectrometry (GC-MS). A significant reduction in FEC was observed in the treated group compared to the control from day 7 until day 15 PT (P<0.05). The highest percentage reduction (72%) was found on day 11 PT. No adverse reactions were observed in all treated animals for the entire trial. The GC-MS analysis of the organic extracts revealed the presence of three fatty acids as compounds with highest abundance. The three compounds that were identified by their mass fragmentation patterns were: 2-Pentadecanone, 6, 10, 14-trimethyl (RT 10.3 min), Pentadecanoic acid, 14-methyl-, methyl ester (RT 10.8 min) and Hexadecanoic acid, ethyl ester (RT 11.2 min). It is concluded that the P. icosandra ethanolic extract obtained from leaves showed in vivo anthelmintic activity against H. contortus when administered orally to goats at a dose of 250 mg/kg BW on two consecutive days. The dose used did not cause any negative effects on the health of goats.