Anti-inflammatory activity of zingiber montanum (j. konig) link ex dietr. Extracts prepared by deep frying in coconut oil

Abstract

© 2020 Faculty of Pharmacy. The Zingiber montanum (J. Konig) Link ex Dietr. (Phlai) rhizome has been used for the treatment of muscular and joint pain. An essential oil from this has been developed into various dosage forms, but there are no studies on the traditional Phlai hot oil extract, which is widely used among Thai traditional practitioners. Commonly a high temperature has been suggested for extraction but some traditional doctors claimed the efficacy of the low temperature extract (LTE, 70-90°C). The objectives of this study were to determine the effect of temperature on the anti-inflammatory activity and investigate the minimum concentration of the most potent extract. The anti-inflammatory activity was determined using the ear-edema model. Phlai oil extracts were prepared traditionally by deep frying the sliced rhizome in hot vegetable oil using three different temperatures. The density and viscosity of all the extracts were recorded. The extract using a high temperature (HTE, 240-260°C) showed the significantly highest anti-inflammation activity (P < 0.05). The minimum concentration that presented a reduction in ear edema was 25% of HTE in coconut oil (P < 0.05). A thin layer chromatogram of the extracts demonstrated that some compounds in the volatile oil remained in the extracts that were exposed to a low temperature, but those were not found in the medium temperature extract (MTE, 170-190°C) and HTE. All extracts contained (E)-4-(3',4'-dimethoxyphenyl)but-3-en-2-ol (compound-D). Other phenylbutanoids and cassumunoids in the HTE may be responsible for anti-inflammation and should be revealed, while quality control should be studied further.