Ruta graveolens L. toxicity in Vampirolepis nana infected mice

Abstract

Objective: To determine possible toxic effects of Ruta graveolens hydroalcoholic extract in gastrointestinal parasitic infection.

Materials and methods: A total of 100 g plant leaves and seeds were powdered and extracted with 1500 mL alcohol/water and administered by gavage to Swiss albino mice infected with Vampirolepis nana. Anti-parasitic evaluation and toxicity assays were carried out in six groups of ten animals each. Treatments were scheduled with both the leaves and the seeds' extracts at doses of 2.5, 5, and 10 mg per gram body weight. Toxicity was comparatively analyzed to a vehicle control group (n = 10) and to a Praziquantel(®) treated. On the fifth day, all the individuals were killed by euthanasia and parasite scores were correlated, giving rise to a relative percentage of elimination to each treatment. Toxicity was achieved by hematology and by clinical chemistry determinations.

Results: The use of the R. graveolens hydroalcoholic extract to treat V. nana infected mice resulted in a mild-to-moderate hepatoxicity associated to a poor anti-parasitic effect. The major proglottids elimination (E%) was achieved at the lowest crude extract concentration with a mild anti-parasitic efficacy from the highest dose; that did not cause a significant elimination of parasites. A decrease of circulating polymorphonuclear-neutrophils associated with a normochromic-normocytic anemia was detected as the extract dose was augmented. The blood aspartate-aminotransferase and alanine-aminotransferase tended be slightly augmented with 100 mg R. graveolens extract.

Conclusion: R. graveolens is an unsafe natural anti-parasitic medicine as its active constituents may be poorly extracted by the popular crude herb infusion. Although it presented a mild anti-parasitic effect in mice, symptoms of natural-products-induced-liver-disease confirmed that its self-medication should be avoided.

Keywords: Anthelmintic activity; Ruta graveolens; Vampirolepis nana; natural-products-induced-liver-disease.

Figure 1

Anthelmintic activity in Swiss albino mice treated with different concentrations of R. graveolens leaves (L) and seeds (S) extract in comparison to Praziquantel^® (PZ) and to Vehicle (V) treatments. Values are expressed as mean ± SD of proglottides eliminated in the different groups of animals treated with 2.5, 5 and 10mg.g-1 (1.1, 2.2 and 4.3mg/cm2). n=10. The symbols * and ** indicate significant values at P<0.05 and P<0.01, respectively.

Figure 2

Non linear dose-response curves for the anthelmintic activity indicating the hormetic tendency of R. graveolens leaves (A) and seeds (B) hydro alcoholic extract given per oz at different concentrations to Swiss albino mice weighting 20g and having a mean corporal mass of 46cm2 (n=10). Values are expressed as mean ± SD of cumulative counts of proglottides eliminated after four consecutive days of experiment. P<0.1.