Tabriz University of Medical Sciences Medical Journal of Tabriz University of Medical Sciences 2783-2031 39 6 2018 02 05 The therapautic effect of Marrubium vulgare, Salvia officinalis and lippia citriodora in killing of toxoplasma gondii tachyzoite and evaluation by MTT assay 44 50 EN Ehsan Shariat Bahadory Abdolhosein Dalimi Asl Seyedeh Somayyeh Mosavipoor Ali Dalir Ghaffari Somayyeh Namroodi Sekhavat Ghaffari Novin Journal Article 2017 12 09 Background: Toxoplasma gondii is intracellular parasites that cause many symptoms such as encephalitis and congenital disorders. Marrubium vulgare, Salvia officinalis and lippia citriodora are herbal drugs that used to kill this organism. Our objective were to evaluate the therapeutic effect of Marrubium vulgare, Salvia officinalis and lippia citriodora in killing of toxoplasma gondii tachyzoite and evaluation by MTT assay Methods: In this survey we used Marrubium vulgare, Salvia officinalis and lippia citriodora suspension plus RPMI medium containing peritoneal tachyzoite after incubation at 37 C0. The measurement done by MTT assay and statistial assesment done by spss19 software. Our investigation based on two mediam (invitro and invivo) to approve our results. Results: In RPMI medium the killing with three herbal drugs were seen and the decrease of Absorbance were seen by MTT assay. The means of OD were 0.05 to 0.16 in presence of herbal drugs but the means of OD were 0.9 to 2.3 in absence of herbal drugs. Conclusion: Marrubium vulgare, Salvia officinalis and lippia citriodora are herbal drugs that are very useful to kill toxoplasma tachyzoite in invitro condition.