Evaluation of anthelmintic activity of selected medicinal plants currently used in ayurveda

Abstract

Single-ingredient plant decoctions, prepared usmg twenty six plants belonging to nineteen Families were selected for this study. These plants are traditionaly used in Ayurveda and Sri Lankan traditional medicine as anthelmintics. The plant preparations were evaluated for anthelmintic activity using infective larvae of Toxocara canis and Haemonchus contortus, as models in in vitro studies and Toxocara canis in in vivo mouse model. Clinical studies to evaluate effects of Leucas zeylanica and Pavetta indica on Enterobius vermicularis infections were also carried out.

In vitro studies included larval migration inhibition assay (LMI) and evaluation of the effect on viability of T canis and H contortus larval forms in the presence of twenty five plant decoctions. Decoctions of twenty plants revealed promising results in the range of 80 - 100% inhibition on heamonchus infective larvae. Decoctions of twelve plants revealed high effectiveness in the range 80-100% with Toxocara canis infective larvae. Furthermore, eight plant decoctions namely, Cassia alata, Cassia occidentalis, Cassia tora, Embelia ribes, Erythroxylum moonii, Justicia adhathoa, Sesbania grandiflora and Vernonia cinera were effective in LMI of both species.

In the in vitro viability studies, several plant decoctions were highly effective in both larval types. All migrated larvae of T canis and H contorsus were dead in decoctions of M oleifera and E. moonii. All migrated H contorsus larvae were dead in decoctions of R. sativus, A. indica and L. zeylanica. All migrated larvae of T canis were dead in decoctions of P. obtusa, S. grandiflora and J. adhathoda.

In vivo studies on migratory larave in mouse model was performed to evaluate Ghanasara preparations with Erythroxylum moonii and Scoparia dulcis to effect on migratory larave of T canies. In this study, Ghanasara of E. moonii was highly effective in inhibition of Toxocara larval migration in the visceral pathway of mouse. It was able to reduce the migration of larvae in most of the organs examined such as heart, spleen, kidney brain and with total clearance in lungs and intestines within a period of seven days of treatment with E. moonii. S. dulcis preparations also demonstrated moderate activity in inhibiting migrating larvae.

Clinical studies were performed using decoctions of Pavetta indica and Leucas zeylanica on adult/children and adults respectively. Results were evaluated based on clinical symptom and feacl examination for worm eggs.

Group (adult) treated with L. zeylanica, reported total absence of nocturnal anal itching, over 80% complete or partial reduction of abdominal pain, loss of appetite, bad breath and eructation and ova were absent in stools after treatment. During the last two days of treatment, abdominal burning sensation was reported by 12% of patients.

Groups (children and adults) treated with decoction of P. indica showed more than 75% reduction of symptoms such as nocturnal anal itching, impaired appetite, abdominal pain, eructation, diarrhoea and also ova were absent in stools after treatment. It is concluded that in treatment of E. vermicularis infections, the decoction of L. zeylanica is highly effective in adults whereas P. indica is highly effective both in children and adults.