Antileishmanial, Immune Modulation and Apoptosis Induction by <i>Astragalus ecbatanus</i> Extract Against <i>Leishmania tropica</i>

Abstract

Background: Due to the unique properties of Astragalus in treating diseases and strengthening the immune system, this study aimed to investigate, for the first time, the immune modulation and apoptosis induction by Astragalus ecbatanus extract against Leishmania tropica. Methods: The study assessed the in vitro efficacy of the Astragalus ecbatanus extract against both the promastigote and amastigote stages of L. tropica (MHOM/AF/88/KK27). Additionally, the effects of the extract on inducing nitric oxide (NO) release and its cytotoxicity on human macrophage cells were determined by calculating the 50% cytotoxic concentrations (CC50). The study also evaluated the Caspase-3-like activity in extract-treated parasites and conducted quantitative real-time PCR to assess the expression of genes associated with T lymphocytes. Results: Our study demonstrated that the A. ecbatanus extract significantly (P < 0.001) decreased the viability of both L. tropica promastigote and amastigote forms compared to the negative control. Moreover, the extract exhibited a high selectivity index (> 10), indicating its strong specificity towards intracellular parasites while showing low cytotoxicity to host cells. Conclusions: The results demonstrated the significant impact of A. ecbatanus ethyl acetate extract on inhibiting and eradicating Leishmania parasites in laboratory settings. While some cellular mechanisms of action were identified, such as immune modulation and apoptosis induction against Leishmania parasites, further investigation is essential to elucidate the specific mechanisms of action and assess the efficacy in animal and human populations.