Chemical Constituents and Cytotoxicity of Euphorbia vajravelui

Abstract

Euphorbia species are important in traditional medicines as well as in horticulture. Though 82 Euphorbia species are reported from India, most of the species are yet to be explored for the phytochemicals or bioactivities. The present study reports the phytochemical and cytotoxicity studies of the Western Ghats endemic plant Euphorbia vajravelui. Compounds were isolated from the extracts of E. vajravelui using column chromatography and were characterized through various spectroscopic techniques. The structures were further confirmed through single crystal XRD. The major pentacyclic triterpene 3β-friedelinol was estimated using a validated HPTLC method. Cytotoxicity of the extracts was tested against human cervical cancer cell line HeLa and normal cardiac myoblasts cell line H9C2 using MTT assay. The pentacyclic triterpenoids taraxeryl acetate, epi-friedelinyl acetate, 3β-friedelinol, taraxerol, 3α-friedelinol and friedelane-2β,3α-diyl diacetate and the phenolic compound 3,4,3'-tri-Omethyl ellagic acid 4'-rutinoside were isolated and characterized from E. vajravelui. Single crystal XRD data of epi-friedelinyl acetate, taraxerol and 3α-friedelinol were also reported. The major compound 3β-friedelinol was found to contain 0.33 ± 0.03%, estimated through a validated HPTLC method. The extracts were non-toxic towards normal cell line H9C2 (cardiac myoblasts) and showed negligible cytotoxic effects towards cervical cancer cell line HeLa upto100 µg/mL concentration. The major compounds isolated from E. vajravelui were triterpenoids and single crystal XRD data unambiguously confirmed the structures. The latex extract was non toxic towards normal cell line H9C2 and cancer cell line HeLa and the result was relevant especially in the context of the eco-toxicological concerns around Euphorbia species. This is the first report of the phytochemical and cytotoxicity studies of the Western Ghats endemic species E. vajravelui.