Enzymolysis-microwave assisted hydrodistillation for extraction of volatile oil from Atractylodes chinensis and its hypoglycemic activity in vitro.

Background Atractylodes chinensis (family Asteraceae) is a perennial herb with many pharmacological effects. Objective Extraction of volatile oil from Atractylodes chinensis was optimized and its hypoglycemic activities were studied. Methods Enzymolysis-microwave assisted hydrodistillation (EMAHD) was adopted to extract the volatile oil, and the technology was optimized using a single-factor experiment that incorporated response surface methodology (RSM). The extraction rates of volatile oil by EMAHD, microwave assisted hydrodistillation (MAHD), and hydrodistillation (HD) methods were compared at different times. The ingredients of Atractylodes chinensis volatile oil were analyzed by gas chromatography-mass spectrometry (GC-MS). Scanning electron microscopy (SEM) were used to analyze the microstructural changes in Atractylodes chinensis residue before and after extraction. The inhibition of α-amylase activity was determined. Results The obtained optimal extraction conditions for EMAHD were as follows: enzyme concentration 1.6%, pH 7, enzymolysis time 20 min, enzymolysis temperature 50 °C, liquid-solid ratio 30:1, microwave power 455W and microwave time 40 min. The levels of the main ingredients and the in vitro inhibition of α-amylase activities were higher for Atractylodes chinensis volatile oil extracted by EMAHD than by HD or MAHD. The powder residue of Atractylodes chinensis remaining after EMAHD showed a ruptured and collapsed cell structure, indicating accelerated dissolution of the volatile oil. Conclusions and highlights EMAHD is deemed a method with many advantages for extraction of volatile oil from Atractylodes chinensis. The volatile oil of Atractylodes chinensis is a promising component for treating hyperglycemia.