Background: Cylindrocarpon destructans (Zins) Scholten is an important pathogenic fungus that causes ginseng root rot in many ginseng growing areas in China. Although C. destructans have been studied worldwide, research on its chemotaxis towards ginseng (Panax ginseng C. A. Meyer) root exudates in the rhizosphere remains limited.Methods and Results: In this study, we collected ginseng root exudates with three different polarities from three-year-old ginseng roots, and performed chemotaxis and spore germination assays to investigate the ability of these exudates to induce the response in C. destructans. The results showed that, compared with other conditions, when C. destructans cultivated at 20°C and a pH of 6 exhibited a strong positive chemotactic response toward 2 ㎎/ℓ aqueous phase, 20 ㎎/ℓ butanol phase, and 0.2 ㎎/ℓ petroleum ether from ginseng root exudates, the chemotactic moving indexes were 0.1581, 0.1638 and 0.1441, respectively. In addition, the spore germination rate with optimal chemotactic parameters were 48%, 53%, and 41% in the aqueous phase, butanol phase and petroleum ether groups, respectiviely, which were significantly higher than that in the control group (23%) (p < 0.05). The mycelial growth rate with optimal chemotactic parameters increased with culture time, and the maximum growth rates in the aqueous phase, butanol phase and petroleum ether groups were 0.425, 0.406 and 0.364 respectively, on the 4th day. The optimal chemotactic parameters were 39.73 ㎎/50 ㎎/ℓ , 48.93 ㎎/50 ㎎/ℓ , and 31.43 ㎎/50 ㎎/ℓ , in aqueous phase, butanol phase and petroleum ether respectively, from ginseng root exudates, compared with 5.5 ㎎/50 ㎎/ℓ , in the control group.Conclusions: The present study revealed that certain ginseng root exudates containing chemical attractants act as nutritional sources or signals for C. destructans and support its colonization of ginseng roots.

In this study, the clinical safety and toxicology of oral ingestion of supplement capsules containing ginsengradix was investigated in healthy young volunteers. This study was a pilot randomized, double blinded, placebo controlledtrial. The healthy volunteers were divided into 6 groups of 20 each (10males and 10 females). They took the ginseng powderfor 35 days (3g/day) for safety evaluation. There were measured general healthy levels such as hematological, biochemical andelectrocardiographic parameters. After the first week, besides Korean white ginseng the other treatments led to an significantincrease of white blood cells. Korean red ginseng increased UREA (blood urea nitrogen) in healthy volunteers, but it didn’texceed the range of normal values, and in the subsequent process of treatment there is no effect of elevating UREA. After thethree weeks, Korean white ginseng showed relatively low the content of blood glucose and low-density lipoprotein cholesterol.After the five weeks, compared with the other treatments, Korean red ginseng increased white blood cells, platelet distributionwidth and average volume of platelet. Korean white ginseng decreased low-density lipoprotein cholesterol. American ginsengdecreased blood creatinine in healthy volunteers. In conclusion, through test the blood routine, urine routine, liver function,renal function, blood glucose, blood lipid and electrocardiogram, the healthy volunteers continuous taking ginsengfor 35 days (3g/day) is safe and reliable, and have no obvious adverse reactions and side effects.