The effect of ultrasonication on the immunomodulatory activity of low‐quality ginseng

This study investigated the effects of ultrasonication extraction (UE) on the immunomodulatory activity of low‐quality ginseng. The results indicate that the optimal conditions for extracting low‐quality ginseng are ultrasonication at 60 kHz and 85°C for 60 min. The extraction yield from the UE was 20% higher than that of the water extraction (WE) at 100°C. The low quality ginseng obtained from the UE exhibited relatively low cytotoxicity toward normal human cells, with an observed toxicity of 15–18% at a concentration of 1.0 mg/mL. The ginseng product obtained following UE induced human B and T cells growth and resulted in concentrations of up to 9.33 × 10⁴ cells/mL and 15.33 × 10⁴ cells/mL, respectively. The ginseng extract also increased the secretion of interleukin‐6 and tumor necrosis factor‐α from these cells by up to 35%, and natural killer/ cell growth was also improved by up to 30%. The UE effectively released 2‐ to 3‐fold higher levels of ginsenosides than the WE. Specifically, the obtained levels of Rb₁, Re, and Rg₁, which are likely immunomodulatory factors, were approximately three times higher after ultrasonication than after WE. These results were further supported by the finding that UE product‐treated macrophages produced higher levels of nitric oxide (21 μM) than macrophages treated with the WE product or with standard ginsenosides. These results demonstrate that this optimized ultrasonication process effectively destroyed the more rigid cell walls of low‐quality ginseng and released high levels of ginsenosides. This work is the first to correlate extraction parameters with both extraction yields and biological activity. The use of low‐quality ginseng can thus be expanded by utilizing a low‐temperature ultrasonic extraction process. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2013