Nitric oxide inhibitory and cytotoxic activities of spice essential oils

Abstract

This study aims to investigate the effects of anise oil, lemongrass oil and cassia oil on nitric oxide production from nitric oxide donor and stimulated macrophage cells. Furthermore, this study also evaluates the cytotoxic effect of essential oils on cell viability of macrophage and human colorectal cancer cells. The results showed that anise oil and lemongrass oil presented higher nitric oxide scavenging capacity by reduction of nitrite formation from NO donor with IC50 of 406.90 and 413.50 μg/ml. In vitro study, cassia oil presented lower NO scavenging capacity. For cellular study, lemongrass oil and cassia oil at concentration of 6.25-25 μg/ml and all concentration of anise oil (6.25-100 μg/ml) presented NO inhibitory activity with no cytotoxic effect of the macrophages. For the cancer cell study, lemongrass oil and cassia oil reduced cell viability of human colorectal cancer cells after 48 h of treatment with IC50 of 77.91 and 32.72 μg/ml, and IC50 was better in 72 h of treatment with 67.96 and 21.94 μg/ml. Nevertheless, anise oil displayed insignificant effect on HT-29 cell viability. Anethole, citral and cinnamaldehyde were identified as main composition of anise oil, lemongrass oil and cassia oil using gas chromatography-mass spectrometry (GC-MS). The results from this study suggested the different effects of essential oils on nitric oxide inhibition of in vitro and cellular study as well as the cytotoxic effect to macrophage and colorectal cancer cell. These results are beneficial for further study of anise oil, cassia oil and lemongrass oil in pharmaceuticals and natural therapies.