Effect of aqueous extract of the plant Mentha longifola in viability of Leishmania donovani in vivo

This study included the using aqueous extract of plant Mentha longifola with the concentration (25 , 50 , 75 ) mg /ml to study its effect on the vitality of the parasite Leishmania donovani in vivo in male laboratory mice Mus musculus . The animals were divided into three groups injected with Leishmania donovani and the next day treated with aqueous extract of the plant M. longifola ,the first group treated with plant extract and concentration 25 mg /ml , second group treated with plant extract and concentration 50 mg /ml and the third group treated with plant extract and concentration 75 mg /ml . In addition to the positive control group which injected with parasite and untreated with plant extract and negative control group which non-injected with parasite and untreated with plant extract . After 60 day of infection with the parasite and treated with plant extract were dissected animals and taking the weights of each the animal s body , liver and spleen to a statement rates of infection in the organs. The current study showed that groups of animals which infected with parasite and treated with plant extract showed a significant decrease (p 0.01) in the weights of the liver , length of spleen , ratio of spleen enlarged , number of parasites in spleen and delayed hypersensitivity compared with positive control group ,and this a decrease was increases with the concentration of the plant extract used where it was noted that the group treated by concentration 75mg/ml of the plant extract does not differ significantly from the negative control group .