Abstract:
This study was aimed to investigate the anti-leishmanial effects of bee products (honey and propolis) by using the causative agent of cutaneous leishmaniasis Leishmania tropica promastigotes, in in vitro culture. In vitro anti-leishmanial efficacy of honey (pine, flower and chestnut) and propolis used in the study were evaluated using the microdilution method. Honey, which is a bee product, was dissolved with RPMI medium containing fetal calf serum (FCS) and diluted in the same medium, and serial dilutions were prepared in concentrations between 62.5-1000 mg/ml. Propolis, on the other hand, was dissolved with ethyl alcohol and only 2.5 μl was used from all these concentrations since the alcohol content was more than 50% in these concentrations prepared and we thought that this rate would negatively effect the parasite development. Then, RPMI containing FCS was diluted in the medium and serial dilutions were prepared at concentrations between 50-800 μg/ml. To the dilutions prepared, the promastigot suspension was added so that their final concentrations in the wells were 1 x 106 promastigot/ml and then the medium was incubated for 24 and 48 hours in 26°C. After the incubation, promastigotes were determined microscopically for morphology, mobility and live parasite density, and cell viability was determined by MTS method and 50% inhibitor concentrations (IC50) were compared with control groups. Anti-leishmanial activity of propolis (50, 100, 200, 400 and 800 μg/ml) and honey (62.5, 125, 250, 500 and 1000 mg/ml) on promastigotes was evaluated in vitro. In microscopic examinations, pine honey showed anti-leishmanial activity starting from 62.5 mg/ml, flower honey 250 mg/ml, and chestnut honey 125 mg/ml, and pine honey was more effective on promastigotes (p< 0.05), and propolis was effective from 100 μg/ml concentration. It has been determined that very low concentrations of propolis caused changes in the morphological structure of the parasites and were more effective than the other bee products. The prevention of cell proliferation and decreasing of the IC50 values according with the time of pine honey (IC50= 109.28 mg/ml), flower honey (IC50= 248.07 mg/ml), chestnut honey (IC50= 147.65 mg/ml) and propolis (IC50= 82.98 μg/ml) applied on L.tropica promastigot cell culture was determined by MTS method. In this study, it was found that various concentrations of pine, flower, chestnut honey and propolis showed anti-leishmanial activity on L. tropica promastigotes. It has been observed that pine honey is more effective on promastigotes after 48 hours of incubation period, and propolis is more effective in both morphology and cell inhibition of the parasites even at very low concentrations. It is believed that these data can be used as an alternative treatment method against cutaneous leishmaniasis infections and further studies are required. © 2020 Ankara Microbiology Society. All rights reserved.