Mortality Effects of Lepidium latifolium Alcoholic Extract Against Pediculus humanus

Background and Objective:
Pediculus humanus capitis is a public health problem that is seen in many countries. The treatment of this ectoparasite is based on synthetic chemical insecticides that most which are harmful and toxic to human health. So, finding them safer and more effective alternatives is needed urgently. In the present study, the pediculicidal activity of methanolic extract of L. latifolium was evaluated for head lice treatment.

Methods: The leaves of the plant L. latifolium were isolated and dried under shade. The alcoholic extract was prepared and  concentrations of 0.12, 0.25, 0.50 and 0.75 mL/cm2 from herbal extract were examined under a World Health Organization (WHO)  bioassay protocol. After the collection of head lice, in vitro tests were started within 30 min.

Results: The lice mortalities were evaluated after 5, 15, 30, 45 and 60 min of exposure. After 30 min of exposure to 0.75 mL/cm2 concentration, all lice were dead. Permethrin 1% and the solvent that has been used for extraction were used as the positive and negative control, respectively.

Conclusion: Head lice must be controlled as a serious disease at an early stage. The present study showed that Lepidium latifolium can well kill the parasite. Our data suggested that this herbal extract formulation of a native plant in Iran is suitable to be used as pediculicides.