Cytotoxicity-reducing and anti-inflammatory effects of a natural herb mixture extract

Background: Natural herb mixture extracts have been used in traditional medicine in many countries for several years and are currently widely used as alternative medicines, even in Western countries. These extracts have long been shown to be effective in alleviating and treating various diseases owing to the various components of herbal medicines. However, it is difficult to verify the efficacy of natural herb mixture extracts in clinical trials, which limits the development of new drugs. Objective: This study was aimed at investigating the efficacy and safety of a natural herb mixture aqueous extract comprising Polyporus umbellatus (PUAE), Polygala tenuifolia (PTAE), and Epimedium koreanum (EKAE). Each of the herbs in this natural herb mixture extract is known to be cytotoxic and have mild anti-inflammatory activity when used singly. We compared the cytotoxicity of single of PUAE, PTAE and EKAE, and their mixture in RAW264.7 cells and then evaluated their possible anti-inflammatory effects. Results: The single extracts decreased the viability of RAW264.7 cells, whereas their mixture did not affect the viability even at the highest concentration (100 ug/mL). In addition, all the tested extracts inhibited NO production and the expression of the inflammation-related proteins (iNOS and COX-2) increased by LPS stimulation. However, the effect was remarkable in cells treated with the mixture compared with cells treated with the single extracts. Conclusion: The natural herb mixture extract comprising PUAE, PTAE and EKAE was confirmed to have a cytotoxicity-reducing effect and a synergistic anti-inflammatory effect compared with that of the individual herbal medicines that made up the natural herb mixture extract.