Potential interactive effects between invasive Lumbricus terrestris earthworms and the invasive plant Alliaria petiolata on a native plant Podophyllum peltatum in northeastern Ohio, USA

We test whether the invasive earthworm Lumbricus terrestris and leaf litter of the invasive herbaceous plant Alliaria petiolata interact to influence the native plant, Podophyllum peltatum using both observational field data and a multi-year experiment. We hypothesized invader interactive effects on the native plant might result from either changes in allelochemical distribution in the soil or nutrient availability mediated by the invasive earthworm pulling leaf litter down into the soil. Within the field data we found that Alliaria petiolata presence and higher soil nitrogen correlated with reduced Podophyllum peltatum cover, and no evidence for an invader-invader interaction. Within the factorial experiment, we found a super-additive effect of the two invaders on plant biomass only when activated carbon was present. In the absence of activated carbon, there were no differences in Podophyllum peltatum biomass across treatments. In the presence of activated carbon, Podophyllum peltatum biomass was significantly reduced by the presence of both Lumbricus terrestris and Alliaria petiolata leaf litter. The absence of an effect of Alliaria petiolata leaves without activated carbon, combined with a failure to detect arbuscular mycorrhizal colonization, suggests that indirect effects of allelochemicals on arbuscular mycorrhizal fungi were not the primary driver of treatment responses. Rather direct nutrient availability might influence a potential interaction between these invaders. Leaf nitrogen content was higher and leaf CO2 concentration was lower in the presence of Lumbricus terrestris, but treatment did not influence maximum photosynthetic rate. While the field data do not suggest a negative interaction between these invaders, the experiment suggests that such an interaction is possible with greater environmental stress, such as increasing nitrogen deposition. Further, even plants with rapid physiological responses to increased nitrogen availability may have other physiological limits on growth that prevent them from compensating from the harm caused by multiple invaders.

Podophyllotoxin Isolated from Podophyllum peltatum Induces G2/M Phase Arrest and Mitochondrial-Mediated Apoptosis in Esophageal Squamous Cell Carcinoma Cells

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers in East Asia and is the seventh leading cause of cancer deaths. Podophyllotoxin (PT), a cyclolignan isolated from podophyllum peltatum, exhibits anti-cancer effects at the cellular level. This study investigated the underlying mechanism of anti-cancer effects induced by PT in ESCC cells. Exposure to increasing concentrations of PT led to a significant decrease in the growth and anchorage-independent colony numbers of ESCC cells. PT showed high anticancer efficacy against a panel of four types of ESCC cells, including KYSE 30, KYSE 70, KYSE 410, KYSE 450, and KYSE 510 by IC50 at values ranges from 0.17 to 0.3 μM. We also found that PT treatment induced G2/M phase arrest in the cell cycle and accumulation of the sub-G1 population, as well as apoptosis. Exposure to PT triggered a significant synthesis of reactive oxygen species (ROS), a loss of mitochondrial membrane potential (MMP), and activation of various caspases. Furthermore, PT increased the levels of phosphorylated c-Jun N-terminal kinase (JNK), p38, and the expression of Endoplasmic reticulum (ER) stress marker proteins via ROS generation. An increase in the level of pro-apoptotic proteins and a reduction in the anti-apoptotic protein level induced ESCC cell death via the loss of MMP. Additionally, the release of cytochrome c into the cytosol with Apaf-1 induced the activation of multi-caspases. In conclusion, our results revealed that PT resulted in apoptosis of ESCC cells by modulating ROS-mediated mitochondrial and ER stress-dependent mechanisms. Therefore, PT is a promising therapeutic candidate as an anti-cancer drug against ESCC for clinical use.

Campylobacter-Enteritis

ZusammenfassungRetrospektiv wurden 6 Fälle von Campylobacter-Enteritis auf eine effektive homöopathische Therapie untersucht. Schnelle Besserung trat unter Arsenicum album, Bryonia alba aut dioica, Cuprum arsenicosum und Guajacum officinale ein. Podophyllum peltatum war weniger effektiv.