Continuous hydrodistillation-ultrasonication flow batch-mode operation system to enhance essential oil extraction from Satureja khuzistanica and evaluation of in vitro anti-inflammatory activity

Satureja khuzistanica Jamzad (SKJ) is a well-known Persian herbal medicine having valuable biological properties. In this work, a continuous flow batch-mode operation system equipped with a Clevenger apparatus coupled with an ultrasound chamber for intensifying the extraction of essential oil (EO) from dried aerial parts of SKJ has been developed. Response surface methodology (RSM) was then employed to optimize the extraction conditions by considering the interaction of the feed-to-solvent, temperature and sonication time parameters. Gas chromatography (GC) and GC/mass spectrometry (MS) analysis were used to characterize the extracted EO components. The optimal operating conditions for the above parameters was attained at 14.66 g L-1, 30.86 degrees C and 39.78 min, consequently. The yield of EO extraction using ultrasound-assisted extraction (UAE) (9.89 mg g(-1) of plant) was approximately 25 % higher than that of the conventional method (7.87 mg g(-1) of plant). Scanning electron microscopy (SEM) established the effective rifts in the plant cell structures using ultrasound wave irradiation for EO extraction. Moreover, the EO's anti-inflammatory properties were investigated by inhibition of the albumin denaturation analyses. The SKJ's EO extracted under optimal conditions revealed a significant anti-inflammatory effect with 89 % inhibition of the albumin denaturation at concentration of 900 mu g mL(-1).