Latent Pathogenic Fungi in the Medicinal Plant Houttuynia cordata Thunb. Are Modulated by Secondary Metabolites and Colonizing Microbiota Originating from Soil.

Latent pathogenic fungi (LPFs) affect plant growth, but some of them may stably colonize plants. LPFs were isolated from healthy Houttuynia cordata rhizomes to reveal this mechanism and identified as Ilyonectria liriodendri, an unidentified fungal sp., and Penicillium citrinum. Sterile H. cordata seedlings were cultivated in sterile or non-sterile soils and inoculated with the LPFs, followed by the plants' analysis. The in vitro antifungal activity of H. cordata rhizome crude extracts on LPF were determined. The effect of inoculation of sterile seedlings by LPFs on the concentrations of rhizome phenolics was evaluated. The rates of in vitro growth inhibition amongst LPFs were determined. The LPFs had a strong negative effect on H. cordata in sterile soil; microbiota in non-sterile soil eliminated such influence. There was an interactive inhibition among LPFs; the secondary metabolites also regulated their colonization in H. cordata rhizomes. LPFs changed the accumulation of phenolics in H. cordata. The results provide that colonization of LPFs in rhizomes was regulated by the colonizing microbiota of H. cordata, the secondary metabolites in the H. cordata rhizomes, and the mutual inhibition and competition between the different latent pathogens.

Endophytic fungi stimulate the concentration of medicinal secondary metabolites in houttuynia cordata thunb.

Endophytic fungi usually establish a symbiotic relationship with the host plant and affect its growth. In order to evaluate the impact of endophytic fungi on the Chinese herbal medicinal plant Houttuynia cordata Thunb., three endophytes isolated from the rhizomes of H. cordata, namely Ilyonectria liriodendra (IL), unidentified fungal sp. (UF), and Penicillium citrinum (PC), were co-cultured individually with H. cordata in sterile soil for 60 days. Analysis of the results showed that the endophytes stimulated the host plant in different ways: IL increased the growth of rhizomes and the accumulation of most of the phenolics and volatiles, UF promoted the accumulation of the medicinal compounds afzelin, decanal, 2-undecanone, and borneol without influencing host plant growth, and PC increased the fresh weight, total leaf area and height of the plants, as well as the growth of the rhizomes, but had only a small effect on the concentration of major secondary metabolites. Our results proved that the endophytic fungi had potential practical value in terms of the production of Chinese herbal medicines, having the ability to improve the yield and accumulation of medicinal metabolites.

CD8+T cells in peripheral blood of patients with acute antituberculosis drug-induced liver injury on the expression and significance of CD28 / 上海预防医学

Objective ] To detect the percentage of CD8+CD2-8、CD8+CD2+8 cells in patients with antituberculosis drug-induced liver injury and investigate their expression on acute liver injury by antituberculosis drugs and clinical significance. [ Methods] The flow cytometry was used to detect the percentages of CD8+CD2-8 and CD8+CD2+8 in peripheral blood of 42 patients with antituberculosis drug-induced acute liver injury, and 232 normal liver function patients with antituberculosis treatment.The mean amount of T cells between the two groups were compared by t-test and when P <0 .05 the difference found in comparison was thought to be statistically significant. [ Results] The percentage of CD8+CD2-8 cells of antituberculosis drug-induced acute injury group was lower than that of antituberculosis with normal liver function group (12.2 ±7.7%and 23.6 ±10.4%) , and the difference was of statistical significance ( t=4.782,P<0.01).And the amount of CD8+CD2+8 cells in antituberculosis drug-induced acute injury group was higher than that in antituberculosis with normal liver function group ( 23.5 ±9.1% and 10.2 ± 6.7%), the difference being statistically significant (t=5.356,P<0.01) too. [Conclusion] The amount of CD8+CD2-8 cells is reduced in peripheral blood of patients with antituberculosis drug-induced acute injury, while the amount of CD8+CD2+8 cells is increased.It is held that CD28 expression on CD8+T cells can be used as a marker of immunological detection in antituberculosis drug-induced acute liver injury.