Spigelia anthelmia Linn is used as a herb and is a common annual weed of cultivation in open re-growths, on unused land in towns as well as on road sides. The plant can grow to approximately 30 cm in height. The aim of this study was to screen extracts of Spigelia anthelmia for their anthelmintic activity against an experimental Nippostrongylus braziliensis infection in rats. Acute oral toxicity occurred at a dose of 1,140 mg/kg, while anthelmintic trials against Nippostrongylus braziliensis in rats using the aqueous fraction showed a progressive decrease in worm count with increasing dose (10, 13, 16, 20 and 25 mg per kg body weight) (p < 0.05). At 25 mg per kg body weight, the worm count was significantly lower than that at 10 mg per kg body weight (p < 0.05).
Animals ; Anthelmintics/*pharmacology/toxicity ; Drug Evaluation, Preclinical ; Lethal Dose 50 ; Loganiaceae/*chemistry ; Medicine, African Traditional ; Nigeria ; Nippostrongylus/*growth&development ; Phytotherapy/*methods ; Plant Extracts/*pharmacology/toxicity ; Rats ; Rats, Wistar ; Strongylida Infections/*drug therapy/parasitology

OBJECTIVETo evaluate the ovicidal and larvicidal activities of aqueous and ethanolic extracts of leaves of Dichrocephala integrifolia (D. integrifolia) against the eggs (fresh and embryonnated), the first and second larval stages of Heligmosomoides bakeri. In order to verify if this medicinal plant possesses active compounds capable of inhibiting the embryonation and hatching of eggs or to induce the mortality of larvae (L1 and L2).

METHODSdried extracts were diluted in distilled FIV water to obtain five different concentrations: 625, 1,250, 2,500, 3,750 and 5,000 µg/mL. Fresh eggs obtained from artificially infected mice feces were exposed to these different concentrations for 48 h. Time of contact for embryonated eggs was 6 h while L1 and L2 larvae were exposed for 24 h. Distilled water (placebo) and 1.5% DMSO were used as negative controls.

RESULTSDistilled water, and 1.5% DMSO had no effect on embryonation, hatching and larval survival. Aqueous extracts of D. integrifolia showed a weak activity against all stages of the parasite at all concentrations tested. On the contrary, the ethanolic extract of D. integrifolia inhibited the embryonation of 87.5% of fresh eggs, the hatching of 81.1% of embryonated eggs and induced the mortality of 98.1% and 98% of L1 and L2 larvae respectively at 5,000 µg/mL.

CONCLUSIONSThe results of the present study indicate that the ethanolic extracts of D. integrifolia contained compounds with ovicidal and larvicidal properties. In spite of these results, in vivo tests, studies on toxicity and mechanism of action of active compounds are also needed to validate the utilisation of this medicinal plant by population of Dschang-Cameroon to treat gastro-intestinal parasites.

Animals ; Antinematodal Agents ; pharmacology ; therapeutic use ; Asteraceae ; chemistry ; Dose-Response Relationship, Drug ; Heligmosomatoidea ; drug effects ; growth & development ; Larva ; drug effects ; Mice ; parasitology ; Ovum ; drug effects ; Plant Extracts ; pharmacology ; therapeutic use ; Plant Leaves ; chemistry ; Rodent Diseases ; drug therapy ; Strongylida Infections ; drug therapy ; veterinary