The Anticancer, Antioxidant and Antimicrobial Properties of the Sesquiterpene ß-Caryophyllene from the Essential Oil of Aquilaria crassna.

ABSTRACT

The present study reports a bioassay-guided isolation of ß-caryophyllene from the essential oil of Aquilaria crassna. The structure of ß-caryophyllene was confirmed using FT-IR, NMR and MS. The antimicrobial effect of ß-caryophyllene was examined using human pathogenic bacterial and fungal strains. Its anti-oxidant properties were evaluated by DPPH and FRAP scavenging assays. The cytotoxicity of ß-caryophyllene was tested against seven human cancer cell lines. The corresponding selectivity index was determined by testing its cytotoxicity on normal cells. The effects of ß-caryophyllene were studied on a series of in vitro antitumor-promoting assays using colon cancer cells. Results showed that ß-caryophyllene demonstrated selective antibacterial activity against S. aureus (MIC 3 ± 1.0 µM) and more pronounced anti-fungal activity than kanamycin. ß-Caryophyllene also displayed strong antioxidant effects. Additionally, ß-caryophyllene exhibited selective anti-proliferative effects against colorectal cancer cells (IC50 19 µM). The results also showed that ß-caryophyllene induces apoptosis via nuclear condensation and fragmentation pathways including disruption of mitochondrial membrane potential. Further, ß-caryophyllene demonstrated potent inhibition against clonogenicity, migration, invasion and spheroid formation in colon cancer cells. These results prompt us to state that ß-caryophyllene is the active principle responsible for the selective anticancer and antimicrobial activities of A. crassnia. ß-Caryophyllene has great potential to be further developed as a promising chemotherapeutic agent against colorectal malignancies.