Chemical composition, antioxidant, antimicrobial and antiproliferative activities of the leaf essential oil of Roxburgh's Cherry (Eugenia roxburghii), an underutilized species

Eugenia roxburghii (Myrtaceae), known as Roxburgh's Cherry, is a wild edible fruit-producing plant having multiple use in traditional and folk medicines in India and Sri Lanka. In spite of its nutritional and medicinal importance, there is no report on the chemical composition and bioactivities of the essential oil (EO) of this species. In this article, the chemical composition of the leaf EO of E. roxburghii has been reported for the first time along with its antioxidant, antimicrobial and antiproliferative activities. GC-MS analysis of EO led to the identification of 41 compounds with beta-caryophyllene (22.32%) as the major constituent. The EO exhibited strong antioxidant capacity in DPPH and ABTS assays with IC50 values of 15.12 +/- 0.23 mu g/mL and 7.32 +/- 0.05 mu g/mL, respectively. It also exhibited strong reducing power ability (EC50 = 1.47 +/- 0.06 mu g/mL). The EO showed highest sensitivity against enteric pathogenic bacteria, Shigella flexneri (ZOI = 24 +/- 0.4 mm, MIC = 31.25 mu g/mL) validating its ethnomedicinal claim against dysentery. Further, E. roxburghii EO showed significant antiproliferative activity against human colon (HCT-116, IC50 = 64.84 mu g/mL) and prostatic adenocarcinoma (PC-3, IC50=70.11 mu g/mL) cell lines. The present study suggests that EO can be used as an antiproliferative agent and for the treatment of enteric diseases.