Antiparasitic potential of Indian honey bee glue against strains of Leishmania donovani sensitive and resistant to synthetic antileishmanial.

Honey bee glue (HBG) or propolis is produced by honey bees and used as cementing material for sealing within the hive which is considered as a waste by the beekeepers. Due to its umpteen biological properties, it is having the potential for drug development against infectious diseases. The management of leishmaniasis relied wholly on injectable chemotherapeutic agents with a lengthy regimen and no vaccine is available. Moreover, the growing drug resistance alarming the entire community about the upcoming menace. Hence, it is of utmost importance to discover and explore new compounds against Leishmania infection, which are effective, safe, and cheaper. The present study was aimed to evaluate the efficacy of Indian honey bee glue (HBG), a natural, resinous by-product of the apiculture industry against the promastigote and amastigote forms of the sensitive and resistant strains of Leishmania donovani. HBG was characterized through GC-MS screening and phytochemical (qualitative and quantitative) analysis was done. In vitro (anti-promastigote) and ex vivo (anti-amastigote) activities against sensitive and resistant strains of L. donovani were assessed. Cytotoxicity, ROS (reactive oxygen species) generation, cell membrane integrity, and cell cycle analysis were evaluated. Chemical characterization by GC-MS revealed the presence of different biologically active components in honey bee glue (HBG). Our results showed the activity of HBG with an IC₅₀ of 27.95 ± 1.53 μg/mL and 29.43 ± 1.54 μg/mL against the sensitive and resistant L. donovani promastigotes respectively. An IC₅₀ of 20.93 ± 1.35 μg/mL and 20.22 ± 1.53 μg/mL was observed against the sensitive and resistant amastigotes of L. donovani. Moreover, the cytotoxicity test against the human cell line showed a CC₅₀ value of 811.30 ± 73.44 μg/mL. In addition to this, it enhanced the ROS production and oxidative stress exhibited by the altered levels of lipid peroxidation, superoxide radicals, lipid bodies, and cell membrane integrity within the parasitic cells and mediated their killing by arresting the DNA in the sub-G0/G1 phase of the cell cycle. The antiparasitic action together with GC-MS data revealed the importance of this by-product from the apiary industry. Therefore, HBG can be a good option to develop a new drug molecule against the deadly infection of Leishmania eventually. [ABSTRACT FROM AUTHOR]