Abstract
The use of Eurycoma longifolia Jack (EL) in combination with honey is widely recognized in conventional medicine because of its aphrodisiac and pyretic properties. However, the effects of honey, a natural deep eutectic solvent (NADES), on the phytochemical stability and anti-inflammatory activity of EL remain unknown. This study aimed to investigate the effect of honey on phytochemical and anti-inflammatory effects of EL. The stabilities of bioactive compounds, including eurycomanone (EU), 9-hydroxycanthine-6-one (9HCO), and 9-methoxycanthine-6-one (9MCO), were evaluated after treating EL with honey. The anti-inflammatory activity was assessed by measuring the inhibition of NO production in lipopolysaccharide-induced RAW264.7 macrophages. The EL formulations treated with honey exhibited significantly higher yields of EU and 9HCO; however, a decrease in 9MCO was observed. After a 90 day infusion, the anti-inflammatory activities of honey-treated EL (9.19-68.73% NO inhibition) and simulated honey-NADES-treated EL (5.37-66.68% NO inhibition) were slightly lower than that of the non-treated EL extract (10.34-77.93% NO inhibition). Nonsugar honey constituents also exhibited anti-inflammatory effects. The combination of EL extract and honey resulted in a slightly lower anti-inflammatory activity (11.66-68.55% NO inhibition) compared with the EL extract. Honey and NADES enhanced the extraction and stabilization of bioactive compounds from EL. The anti-inflammatory properties of EL were preserved after honey treatment, indicating that honey-treated EL is a potential natural treatment for inflammatory conditions.