A pro-apoptotic effect of Landrace of Piper betle- Bangla Mahoma on Leishmania donovani may be due to high content of eugenol

Abstract

In the absence of effective and safe treatment of Kala-azar (VL) - a most devastating parasitic disease caused by Leishmania donovani a need for the search of antileishmanial from natural resources, in common use, is imperative. Recently, a comparative in vitro antileishmanial activity of methanolic extract of two landraces of Piper betle- Bangla Mahoba (PB-BMM) and Kapoori Vellaikodi (PB-KVM) has been reported. Herein, the putative pathway responsible for death induced by the effective extract of PB-BMM in promastigotes as well as intracellular amastigotes form of L. donovani was assessed using various biochemical approaches. It was observed that PB-BM is capable of selectively inhibiting both the stages of Leishmania parasites by accelerating apoptotic events by generation of ROS targeting mitochondrion without any cytotoxicity to macrophages. Study was extended to reason out the presence/absence of activity in PB-BMM and PB-KVM on the basis of differences in essential oil composition present in methanolic extract assessed by gas chromatography and mass spectra. The essential oil from PB-BM was found to be rich in eugenol as compared to PB-KV. The antileishmanial efficacy of PB-BMM mediated through apoptosis is probably due to the higher content of eugenol in active landrace. This observation emphasizes the need of extending the studies related to traditional medicines from bioactive plants below species to gender/landrace level for better efficacy and reproducibility.