Chemical profile and antiproliferative activity of essential oil of Centella asiatica from Mebo, Pasighat in Arunachal Pradesh, India

Abstract Centella asiatica (CA) is a perennial herb with critical uses in traditional medicines. This study reports the chemical composition of the essential oil of C. asiatica (CAEO) collected from Mebo, a high altitude location in Arunachal Pradesh in India, and its antiproliferative activity. Hydrodistillation yielded pale yellow coloured essential oil (0.2 mL, 0.14% v/w). Twenty-five compounds were identified in CAEO by gas chromatographic analysis of which sesquiterpene hydrocarbons constituted 87.82%, followed by oxygenated sesquiterpenes (2.57%), monoterpene hydrocarbons (1.38%) and other miscellaneous compounds (2.28%). Sesquiterpenes, α-humulene (41.31% ± 0.03), E-caryophyllene (19.72% ± 0.01), α-copaene (7.98% ± 0.00), β-elemene (5.56% ± 0.08) and γ-muurolene (5.18% ± 0.01), were the major constituents in CAEO. In MTT assay CAEO displayed significant cytotoxicity against SKBr3 and DLA cells with CD50 values of 4.7 µg/mL and 9.2 µg/mL, respectively. The major components of CAEO, α-humulene and (E)-caryophyllene, displayed cytotoxicity on SKBr3 and DLA cells, whereas (E)-caryophyllene demonstrated higher toxicity than α-humulene. CD50 values of (E)-caryophyllene on SKBr3 and DLA cells were 51.6 and 47.2 µg/mL, respectively. The antiproliferative activity of CAEO is due to the synergistic effects of its terpenoid constituents, and it supports the nutritional and medicinal uses of CA. GRAPHICAL ABSTRACT