Expression analysis of DHFR and PTR1 genes in Leishmania major expose to olive leaf extract

Among neglected tropical diseases (NTD) following malaria, leishmaniosis has claimed the largest mortality rate (Georgiadou, Makaritsis, and Dalekos 2015). None of the current anti-leishmanial drugs can be consid-ered ideal (Minodier and Parola 2007; Mohapatra 2014). The dihydrofolate reductase-thymidylate synthase (DHFR-TS) leads to DNA synthesis in the parasite and its inhibition causes the death of the parasite. Mean-while, pteridine reductase1 (PTR1) enzyme, because of having a similar role to DHFR in the parasite, causes by-pass of DHFR enzyme inhibition thereby resulting an incidence of drug resistance in the parasite (Nare et al. 1997b). Considering the current problems regarding leishmaniosis treatment, developing new drugs with less toxicity and greater efficacy plus lower costs has changed into a necessity. The present study examined the effect of olive leaf extract (OLE) at concentrations 6.25, 12.5, 25, 50, and 100 mu g/ml on the expression of DHFR and PTR1 genes in Leishmania major parasite. The parasite samples were incubated in RPMI1640 culture medium in the presence of five mentioned concentrations of OLE. A quantitative real-time PCR technique was used to analyze the DHFR and PTR1 gene expressions. The results revealed that the expression of DHFR gene at 6.25 mu g/ml extract increased significantly (p<0.05), while it diminished significantly at 25 mu g/ml. At other studied concentrations, DHFR gene showed underexpression compared to the control group, which was not statistically significant (p>0.05). The expression of PTR1 gene at concentrations 6.25, 50, and 100 mu g/ml of the olive leaf extract increased significantly (p<0.05). The expression of PTR1 gene at 12.5 mu g/ ml concentration decreased compared to the control group, while it increased at 25 mu g/ml, though the changes in the gene expression at these two concentrations were not statistically significant (p>0.05). The findings of the present study suggest that OLE can reduce DHFR expression, but its effect of reducing PTR1 expression was not very notable, with its influence being greater on DHFR underexpression rather than PTR1.(c) 2023 SAAB. Published by Elsevier B.V. All rights reserved.

Automated summary

Olive leaf extract (OLE) can significantly reduce the expression of DHFR gene and have a slight effect on the expression of PTR1 gene in Leishmania major parasite.