New value-adding opportunities for natural therapeutic products in the Australian Ginger Industry
Ginger (Zingiber officinale) is one of the best-known and most important spices with a long history of the use of the ginger rhizome in Chinese and Ayurvedic medicine. It is an ingredient in more than half of all traditional Chinese medicines, and it has a wide range of pharmacological effects. In western alternative medicine, ginger is used to prevent nausea and motion sickness and to treat inflammatory (rheumatic) conditions. In this study, ginger oil produced by supercritical fluid extraction with pressurised CO2 was further fractionated using preparative HPLC. The resultant fractions were assessed for their anti-inflammatory activity using cell culture and animal model systems. The results showed that the whole ginger oil and some of the isolated fractions were able to reduce the inflammatory reactions in the model systems used. This information gives support to the use of ginger and its extracts for the treatment of medical conditions such as arthritis and rheumatism. Further work in the area should involve a more thorough fractionation and characterisation of the major (and minor) components of the ginger oil. While this study has identified groups of compounds with (and without) bioactivity, the isolation, characterisation and assessment of individual components may provide a greater understanding of the mode of action of this widely used traditional medicine.