Composition, antioxidant capacity and cytotoxic activity of Eugenia uniflora L. chemotype-oils from the Amazon

• Published in: Journal of ethnopharmacology Vol. 232; pp. 30 - 38
• Main Authors: Figueiredo, Pablo Luis B., Pinto, Laine C., da Costa, Jamile S., da Silva, Alberto Ray C., Mourão, Rosa Helena V., Montenegro, Raquel C., da Silva, Joyce Kelly R., Maia, José Guilherme S.
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 25-03-2019
• Subjects: Curzerene; Cyclic sesquiterpenes; Essential oils; Multivariate analysis; Myrtaceae; Myrtaceae; Curzerene; Multivariate analysis; Cyclic sesquiterpenes; Essential oils; essential oils; cyclic sesquiterpenes; multivariate analysis; curzerene
• ISSN: 0378-8741; 1872-7573
• DOI: 10.1016/j.jep.2018.12.011

Oils and extracts of Eugenia uniflora have been reported as antimicrobial, antifungal, antinociceptive, antiprotozoal, antioxidant and cytotoxic.
The oils of five specimens (E1 to E5) that occur in the Brazilian Amazon were extracted, analyzed for their chemical composition, and submitted to antioxidant and cytotoxic assays.
Oils were hydrodistilled, analyzed by GC and GC-MS, and submitted to PCA and HCA analyses. The antioxidant activity of the oils was evaluated by the DPPH radical scavenging and the β-carotene/linoleic acid assays. Antiproliferative effects of the oils and curzerene were tested against colon (HCT-116), gastric (AGP-01), and melanoma (SKMEL-19) human cancer cell lines and a normal human fibroblast cell line (MRC-5), using MTT assay.
Oxygenated sesquiterpenes and sesquiterpene hydrocarbons such as curzerene, selina-1,3,7(11)-trien-2-one, selina-1,3,7(11)-trien-2-one epoxide, germacrene B, caryophyllene oxide, and (E)-caryophyllene were predominant in the oils. PCA and HCA analyses classified the oils samples into four chemotypes. TEAC values of chemotype II (E3 oil, 228.3 ± 19.2 mg TE/mL) and chemotype III (E4 oil, 217.0 ± 23.3 mg TE/mL) displayed significant antioxidant activities. The oils E2 and E4 showed cytotoxic activity against all cell lines tested HCT-116 (IC50 E2:16.26 μg/mL; IC50 E4:9.28 μg/mL), AGP-01, (IC50 E2:12.60 μg/mL; IC50 E4:8.73 μg/mL), SKMEL-19 (IC50 E2:12.20 μg/mL; IC50 E4:15.42 μg/mL), and MRC-5 (IC50 E2:10.27 μg/mL; IC50 E4:14.95 μg/mL). Curzerene showed the more significant activity against melanoma cells (SKMEL-19, IC50:5.17 μM), induced apoptosis at 5.0 μM and 10.0 μM compared to DMSO, exhibiting a decrease in the cell migration at 5.0 μM and 10.0 μM, after 30 h of treatment.
The curzerene chemotype oil and E. uniflora oils can be indicated as drug candidates for anticancer activity of the lung, colon, stomach, and melanoma, with a real prospect to their subsequent phytotherapeutic development.
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