Evaluation of Morphine with Imiquimod as Opioid Growth Factor Receptor or Nalmefene as Opioid Blocking Drug on Leishmaniasis Caused by Leishmania major in Vitro

In this research, the effect of morphine on promastigotes and amastigotes of Leishmania major has been investigated in the presence of nalmefene as a blocking opioid drug and imiquimod as an opioid growth factor receptor.

This study was conducted at Tarbiat Modares University, Tehran, Iran in 2015-2018. Morphine with different concentration (0.1, 1, 10 and 100 1µg/ml) alone and with imiquimod (0.01, 0.1 and 1µg/ml) and nalmefene (0.1, 1 and 10 µg/ml) on promastigotes and amastigotes in macrophages and also the percentage of infected macrophages was investigated. For evaluation of the apoptosis, we used flow cytometry method. The effect of imiquimod and nalmefene on glucantime and amphotericin B as current drugs for treatment of leishmaniasis was evaluated too.

The effect of morphine on promastigotes and amastigotes has a reverse relationship with its concentration. The results of flow cytometry for drug-treated promastigotes revealed that apoptosis and necrosis did not increase markedly relative to the control group. A combination of morphine and imiquimod in concentrations of 0.05, 5 and 5 µg/ml had a pronounced effect on reduction and prevention of macrophage infection with amastigotes. Morphine at a concentration of 0.1 µg/ml plays the role of adjunctive treatment. In amastigote assay we found the better results in group that get glucantime 25 µg/ml+ imiquimod 0.5 µg/ml.

This effect is strengthened with imiquimod and weakened with nalmefene. Using high dose morphine and nalmefene had reverse effects. They suppress immune system and had no controlling effect in macrophages amastigote infection and reduction of promastigotes.