Abstract

Green grass jelly (Cyclea barbata Miers.) is a plant from Indonesia that is believed to have anti-inflammatory activity. This study aims to find the optimum condition in grass jelly extraction using the ionic liquid-microwave assisted extraction (IL-MAE) and to find its lipoxygenase inhibitory activity. Some parameters variable of the IL-MAE method were designed to obtain the optimum condition, including extraction time, liquid-solid ratio, and ionic liquids concentration. The optimization analysis used response surface methodology with Box-Behnken design (17 trials) to obtain predictive model and total flavonoid content (TFC) as a response surface value. Whereas, lipoxygenase inhibitory activity (LIA) was used lipoxygenase enzyme and baicalein as a positive control. In the present study, the optimum condition was suggested by RSM analysis with parameter variables, including extraction time of 18 minutes, 1-butyl-3-methylimidazolium bromide ([BMIM]Br) concentration of 2.24 mol/L, and the liquid-solid ratio of 42 mL/g. The equation of regression quadratic model was obtained to predict the TFC as follows TFC=2.42A+2.43B+1.42C+0.33AB–3.21AC–0.46BC–5.49A2–3.70B2–1.57C2+28.32 with R2 = 0.8416. According to the lipoxygenase inhibitory activity assay of each extract, the highest of activity was found at 12th trials with 69.29% and has a significant correlation with TFC based on analysis of Shapiro-Wilk normality and Pearson correlation test. This study was an early stage to develop the extraction method to obtain the target compound from the plant in an efficient, rapid, and environmentally friendly.

Key words: Cyclea barbata Miers., ionic liquid-microwave assisted extraction, lipoxygenase activity inhibition, total flavonoid content