Background & aim: Toxoplasmosis is one of the common parasitic diseases of humans and animals that is caused by a protozoan Toxoplasma gondii. Henna plant (Lowsonia inermis) is effective against a wide range of diseases. Since pyrimethamine and sulfadiazine medications are first-line drugs for treatment of toxoplasmosis, they have adverse effects. On the other hand, there has been a particular booming despite the increasing resistance of parasites to chemical drugs, traditional treatments and the use of medicinal plants. The aim of this study was to study the effect(s) of henna hydroalcoholic extract on Toxoplasma gondii parasite in in-vitro and in-vivo environments.

Methods: The present experimental study was conducted on 35 mice. A sample of Henna leaves was prepared and extracted using 80% ethanol. The direct effect of henna hydroalcoholic extract at concentrations of 2, 4, 8, 16, 32, 64, 128, 256 and 512 μg / ml on Toxoplasma tachycardia was investigated by flow cytometry. In order to evaluate the anti-toxoplasmic effect of henna extract on in vivo, 4 groups of 5 mice were infected with Toxoplasma tachyzoites of 16, 32, 64, and 128 mg / kg Hana hydroalcoholic extracts concentrations as gavage. A group of 5 mice were infected with tachyzoite of Toxoplasma which received sulfadiazine as a positive control group and a group of 5 mice were infected with tachyzoite of Toxoplasma without a prescriptive drug as a negative control. Finally a group of 5 mice were considered for measuring toxicity of henna extract. The collected data were analyzed using one-way ANOVA and Kaplan-Meier tests.

Results: Flow cytometric results indicated that IC50 of henna on Toxoplasma tachyzoites was 100 μg /ml. The results of the anti-Toxoplasma effect of henna extract on intact media indicated that no significant difference were appreciated between different concentrations and survival rate in rats (p = 0.85) among the test groups treated with different concentrations of the extract in compared with positive and negative control.

Conclusion: The results of this study indicated that the effect of henna hydroalcoholic extract on in-vivo settings was not significant, although it was effective in in-vitro environment. The unsuccessfulness of the extract in in-vivo conditions may have been due to inadequate absorption of the drug in the gastrointestinal tract, problems during gavage, the metabolism of the drug and rapid clearance of the drug.