Chemical Composition and In Vitro and In Silico Biological Activities of Myrciaria tenella (DC.) O.Berg (Myrtaceae) Essential Oil from Brazil

Myrciariatenella O.Berg, a native plant species of Brazil, exhibits pharmacological applications, including antitumor activity. In this study, we isolated the essential oil (EO) of M. tenella and identified its phytochemical profile. In addition, we determined the in vitro and in silico cytotoxic activities of EO in nontumor and tumor cell lines (gingival fibroblasts and oral squamous cell carcinoma, respectively) and its free radical scavenging activity (i.e., antioxidant activity) using ABTS and DPPH assays. The EO of M. tenella primarily constitutes hydrocarbons and oxygenated sesquiterpenes, with (E)-caryophyllene (33.95%), δ-cadinene (7.4%), caryophyllene oxide (4.74%), and viridiflorene (4.49%) as its four major components. EO effectively suppressed the cell viability of CAL-27 tumor cells to below 70% at concentrations of 125 and 250 μg/mL and exhibited a free radical inhibition potential of 75.63 ± 0.41% and 28.46 ± 0.36%, respectively, in the DPPH and ABTS assays. This chemical and biological potential may be attributed to the major compounds present in EO, as well as the molecular coupling simulations conducted, which revealed the anticancer mechanism of EO in the sesquiterpenes (E)-caryophyllene, δ-cadinene, caryophyllene oxide, and viridiflorene.