Optimization of microwave-assisted extraction to obtain a polyphenol-rich crude extract from duku (Lansium domesticum Corr.) leaf and the correlation with antioxidant and cytotoxic activities

The present study employed microwave-assisted extraction (MAE) as a method to extract a crude extract high in polyphenols from the leaves of duku (Lansium domesticum Corr.), a medicinal plant indigenous to Indonesia. The study acquired data on the impact of various extraction parameters, such as ethanol concentration (X₁), microwave power (X₂), and extraction time (X₃), on the levels of total phenolics content (TPC), total flavonoids content (TFC), and antioxidant activity using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. The extraction process was optimized using a Box-Behnken design (BBD) and response surface methodology (RSM). The optimal conditions were achieved with an X₁ of 75%, an X₂ of 315 W, and an X₃ of 8.5 min. The aforementioned experimental settings yielded results of 86.176 mg GAE/g, 31.585 mg QE/g, and 75.850% for the TPC, TFC, and antioxidant activity, respectively. The extract included several significant active chemicals, including octadecanoic acid, undecane, 2-methyl-, 9-octadecenoic acid (Z)-hexyl ester, pentadecanoic acid, 9-hexadecanoic acid, phenolic and flavonoid compounds. The cytotoxic activity against MCF-7, T47D, and 4T1 cell lines was found to be slowed when exposed to crude extract doses ranging from 7.81 to 500.00 μg/mL. The present study's results suggest that MAE is a viable technique for extracting a polyphenol-rich crude extract from duku leaf. This extract shows promise as a natural antioxidant and has potential as an anti-breast cancer agent.