Pyrazine, 2-ethylpyridine, and 3-ethylpyridine are cigarette smoke components that alter the growth of normal and malignant human lung cells, and play a role in multidrug resistance development.

Lung cancer is one of the few human diseases for which the primary etiological agent, cigarette smoke (CS), has been described; however, the precise role of individual cigarette smoke toxicant in tumor development and progression remains to be elusive. The purpose of this study was to assess in vitro the effects of previously identified cigarette smoke components, pyrazine, 2-ethylpyridine, and 3-ethylpyridine, on non-tumorigenic (MRC5) and adenocarcinomic (A549) human lung cell lines. Our data showed that the administration of three cigarette smoke components in combination perturbed the proliferation of both normal and adenocarcinomic cells. Study of malignant cells revealed that CS components were cytotoxic at high concentration (10(-6) M) and stimulatory in a dose-dependent manner at lower concentrations (10(-8) M to 10(-10) M). This adverse effect was enhanced when adenocarcinomic cells were maintained in hypoxia resembling intratumoral environment. Furthermore, exposure to pyrazine, 2-ethylpyridine, and 3-ethylpyridine induced oxidative stress in both normal and malignant cells. Finally, assessment of P-gp activity revealed that multidrug resistance was induced in CS component exposed adenocarcinomic lung cells and the induction was augmented in hypoxia. Taken together, pyrazine, 2-ethylpyridine, and 3-ethylpyridine adversely altered both normal and diseased lung cells in vitro and data collected from this study may help lung cancer patients to understand the importance of quitting smoking during lung cancer treatment.

Experimental evaluation of the sustainability of dwarf bamboo (Pseudosasa usawai) sprout-harvesting practices in Yangminshan National Park, Taiwan.

Sustainable harvest of natural products that meets the needs of local people has been viewed by many as an important means for sustaining conservation projects. Although plants often respond to tissue damage through compensatory growth, it may not secure long-term sustainability of the populations because many plants enhance individual well-being at the expense of propagation. Sustainability may further be threatened by infrequent, large-scale events, especially ill-documented ones. We studied the impacts of sprout harvesting on sprout growth in a dwarf bamboo (Pseudosasa usawai) population that has seemingly recovered from an infrequent, large-scale masting event. Experimental results suggest that although a single sprout harvest did not significantly alter the subsequent abundance and structure of sprouts, culm damage that accompanied sprout harvesting resulted in shorter, thinner, and fewer sprouts. Weaker recovery was found in windward, continually harvested, and more severely damaged sites. These findings suggest that sprout growth of damaged dwarf bamboos is likely non-compensatory, but is instead supported through physiological integration whose strength is determined by the well-being of the supplying ramets. Healthy culms closer to the damage also provided more resources than those farther away. Sustainable harvesting of sprouts could benefit from organized community efforts to limit the magnitude of culm damage, provide adequate spacing between harvested sites, and ensure sufficient time interval between harvests. Vegetation boundaries relatively resilient to infrequent, large-scale events are likely maintained by climatic factors and may be sensitive to climate change. Continual monitoring is, therefore, integral to the sustainability of harvesting projects.

In vitro assessment of Macleaya cordata crude extract bioactivity and anticancer properties in normal and cancerous human lung cells.

The purpose of this study is to assess the bioactivity and anticancer properties of Macleaya cordata crude extract in vitro using normal fetal lung fibroblast MRC5 and adenocarcinomic epithelial cell A549 as model systems,. Treatment of extract induced cell detachment, rounding, and irregularity in shape, in both normal and adenocarcinomic human lung cells, in accompanied of significant reduction in cell proliferation. The data indicated that necrosis appeared to be involved in compromising cell growth in both types of lung cells since membrane permeability and cell granularity were elevated. Although apoptosis was evident, the responses were differential in normal and diseased lung cells. Viability of treated MRC5 cells was reduced in a dose-dependent manner, demonstrating that the normal lung cells are sensitive to the extract. Surprisingly, A549 viability was slightly elevated in response to extract exposure at low concentration, implying that cells survived were metabolically active; the viability was reduced accordingly to treatment at higher concentrations. The present findings demonstrate that the crude extract of M. cordata contains agents affecting the functioning of normal and diseased lung cells in vitro. The observed cytotoxic effects against adenocarcinomic lung cells validate the potential of using M. cordata as herbal intervention in combined with conventional chemotherapy for lung cancer treatment.