Antileishmanial activity of essential oil from a high-altitude herb, Heracleum pinnatum: an in vitro and in silico analysis

Abstract

Heracleum pinnatum, an aromatic herb, is used as a traditional medicine in the Amchi system of Trans-Himalayan Ladakh (India). The study evaluates the leishmanicidal and cytotoxic potentials of H. pinnatum essential oil (HPEO). HPEO was found to be non-toxic against RAW 264.7 cell lines (CC₅₀ = ∼56.42 μg mL⁻¹) with a selectivity index (SI) of >28.2. It restricted the proliferation of promastigotes of Leishmania donovani (IC₅₀ < 2 μg mL⁻¹). GC-MS coupled with GC-FID revealed 26 components (98.05% of EO), with bornyl acetate (42.45%), γ-terpinene (14.05%), p-cymene (10.94%), and limonene (9.06%) being the major components. In silico docking revealed that the major components also bonded efficiently with the metabolic enzymes of L. donovani, disrupting and inhibiting the pathways and affecting the survival of the parasite. The research demonstrates that HPEO exhibits potent antileishmanial properties, potentially attributed to its inhibition of specific metabolic pathways utilised by the parasite.

Keywords:

• Antileishmanial activity
• Cytotoxicity
• Essential oil
• In silico
• Leishmania donovani
• Leishmaniasis