Anthelmintic effect of <i>Portulaca oleracea</i> Linne (Portulacacea) against gastrointestinal parasite <i>Haemonchus contortus</i> Rudolphi and toxicity screenings

Abstract

Background: The resistance of gastrointestinal worms to synthetic anthelmintics (Levamisole) leads us to highlight the Cameroonian pharmacopoeia. The main objective of the present work is to look for an alternative treatment for haemonchosis, based on active secondary metabolites, from Portulaca oleracea, with less or no side effects and accessible to all.
Methods: The Haemonchus contortus cycle test was performed at varying concentrations. Levamisole and PBS were the positive and negative controls respectively. Phytochemical screening was performed by standard staining and precipitation methods. Acute and sub-acute toxicity tests of Portulaca oleracea EA were performed according to OECD 425 and 407 respectively.
Results: EM at 48 h of incubation inhibited eggs with an LC₅₀ of 3.44. There was more larvicidal effect of ME with an LC₅₀ value of 3.54 at 48 h incubation. At 24 h of incubation at the final concentration of 1000 μg/mL the anthelmintic effect of EA, ME and levamisole were noted with LC₅₀ values of 0.057, 0.096, and 0.069 respectively. Phytochemical screening revealed the presence of some secondary metabolites in EA and ME of Portulaca oleracea. The result of the assays shows that ME is richer in total polyphenol (50.884 mg EAG/g DM) and flavonoids (5.688 mg RE/g DM) compared to EA which has (12.998 mg EAG/g DM) and (1.847 mg EC/g DM) respectively. However, there are more tannins in EA (5.688 mg RE/g DM) compared to ME (1.847 mg EC/g DM). The acute and subacute toxicity test showed no toxicity in mice and rats respectively.
Conclusion: In view of the above, Portulaca oleracea possesses anthelmintic effects on the parasite Haemonchus contortus and is not toxic at the experimental therapeutic dose, which may open a way for the searching of a new anthelmintic drug.