Anti-Schistosomal Properties of the Wormseed Plant, ChenopodiumAmbrosoides (Family: Chenopodiacea)

Abstract

Plants may contain ingredients that have anti-parasitic activity against parasites of medical significance. Chenopodium ambrosoides (Wormseed) a wide spread herb in the Family Chenopodiacea was investigated for anti-schistosomal activity against the human trematode parasite, Schistosoma mansoni. The plant is well known for its vermifuge and anti-helminthetic properties. The root, stem, leaves and fruit of the plant were obtained and then the dried powder was extracted sequentially using n-hexane, dichloromethane, methanol and distilled water as solvents. After drying, the texture of the extracts ranged from semi-solid to solid. The texture of the extracts was probably due to the solvent used and the contents of part of the plant extracted. Mice were infected with S. mansoni and treated with extracts at week 4 postinfection. They were perfused at week 6 to recover worms. Gross pathology and histopathology were recorded. Aqueous (leaf) had 46%worms reduction, methanol (fruit) had 23% worms reduction and Praziquantel had 34% worms reduction.Aqueous (leaf) and methanol (fruit) extracts were significantly similar to Praziquantel (p > 0.05) and significantly different from infected controls (p < 0.05).This showed that aqueous (leaf) and methanol (fruit) extracts were efficacious against S. mansoni in terms of worms reduction. Other extracts wormsrecovery were similar to infected controls, hence they were not protective. Aqueous (leaf) and methanol (fruit) had similar gross pathology to Praziquantel while all the other extracts had similar gross pathology to infected controls. This means that aqueous (leaf) and methanol (fruit) extracts reduced gross pathology as a protective measure to S. mansoni while other extracts did not protect against S. mansoni infection. Both aqueous (leaf) and methanol (fruit) had mean glanuloma sizes significantly similar to Praziquantel (p > 0.05) meaning that they were able to protect by reducing granuloma sizes. The two extracts aqueous (leaf) and methanol (fruit) found to be efficacious were used in in vitro test against S. mansoniworms (5 males and 5 females).Aqueous (leaf) extract killed all worms at concentration of 0.05 mg/ml and in 5th min. Its killing was dependent on ionizing effect of water. Methanol (fruit) extract killed all worms at concentration of 0.3 mg/ml in 15th min. The killing was dependent on concentration of the extract. The mortality effect aqueous (leaf) and methanol extracts were statistically similar to Praziquantel (p > 0.05). Schistosome antigens (SWAP and SSP) IgG responsesof serum obtained from mice infected with S. mansoni and treated withaqueous (leaf) extract, methanol extract, Praziquantel and infected controls were assayed using ELISA. The aqueous (leaf) extract, methanol (fruit) extractand the Praziquantel had similar IgG responses to infected controls (p> 0.05) inspite of the fact that the first 3 had lowerworms recovery than infected controls. This shows that they were killing worms directly and also via the immune response. This characteristic has been reported for Praziquantel. Aqueous (leaf) extract was better than methanol (fruit) extract. Isolation of crude extracts was carried out using Thin Layer Chromatography (TLC). Results of finger profiles mobile of C. ambrosoides extracts showed aqueous (leaf) extract had more Rf spots than methanol (fruit) extract but they were significantly similar (p > 0.05) suggesting that both aqueous (leaf) and methanol (fruit) extracts had similarcompounds possessing anti- schistosomal activity.The results of this study suggest that Chenopodium ambrosoides aqueous (leaf) and methanol (fruit)extracts have remarkable anti-schistosomal properties which are similar to Praziquantel.Both aqueous (leaf) and methanol (fruit) extracts should be investigated to determine their toxicity and their active ingredients characterised. They should also be tested against other parasites as a source of anti-parasitic compounds for novel drug development.