Comparison of reactive oxygen scavenging systems between a cetacean (DKN1) and a porcine renal epithelial cell line (LLC-PK1)

Protective effect of Peucedanum praeruptorum Dunn extract on oxidative damage of LLC‑PK1 cells induced by H2O2

Peucedanum praeruptorum Dunn extract (PPDE) is a well-known treatment used in traditional Chinese medicines, where it is most commonly used to treat coughs and symptoms such as headaches and fever. In the present study, the antioxidant capacity of PPDE in vitro was determined by scavenging experiments using DPPH, ABTS+·, ·OH, and ·O2-. The cell survival rate was determined by MTT assay. The MDA, SOD, CAT, GSH, and GSH-Px content were determined by colorimetry assays. The expression levels of antioxidant genes SOD, CAT, GSH, and GSH-Px were assessed by reverse transcription-quantitative PCR. HPLC was used to identify the PPDE components. The results suggested that PPDE had scavenging effects on DPPH, ABTS, hydroxyl, and superoxide anion radicals in a concentration-dependent manner; H2O2 treatment resulted in oxidative stress in LLC-PK1 cells, and the degree of injury of LLC-PK1 cells following PPDE treatment was improved, which was positively correlated with its concentration. Peucedanum praeruptorum Dunn extract treatment reduced the content of MDA and increased the content of CAT, SOD1, GSH, and GSH-Px. The mRNA expression levels of antioxidant genes detected by quantitative PCR were consistent with changes in CAT, SOD, GSS, and GSH-Px. Additionally, the trend in CAT, SOD1, GSH, and GSS protein expression levels was also consistent at the mRNA level. PPDE was found to consist of isochlorogenic acid C, myricetin, baicalin, luteolin, and kaempferol. Therefore, PPDE, which was formed of products derived from natural substances, functioned in the inhibition of oxidative damage. The present study aimed to obtain a better understanding of the traditional Chinese medicine Peucedanum praeruptorum Dunn and preliminarily elucidate its antioxidant mechanism at the cellular level. Further animal or human experiments are required to verify the antioxidant effects of PPDE for further development and utilization.

Selenium protein identification and profiling by mass spectrometry: A tool to assess progression of cardiomyopathy in a whale model

Non-ischemic cardiomyopathy is a leading cause of congestive heart failure and sudden cardiac death in humans and in some cases the etiology of cardiomyopathy can include the downstream effects of an essential element deficiency. Of all mammal species, pygmy sperm whales (Kogia breviceps) present the greatest known prevalence of cardiomyopathy with more than half of examined individuals indicating the presence of cardiomyopathy from gross and histo-pathology. Several factors such as genetics, infectious agents, contaminants, biotoxins, and inappropriate dietary intake (vitamins, selenium, mercury, and pro-oxidants), may contribute to the development of idiopathic cardiomyopathy in K. breviceps. Due to the important role Se can play in antioxidant biochemistry and protein formation, Se protein presence and relative abundance were explored in cardiomyopathy related cases. Selenium proteins were separated and detected by multi-dimension liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS), Se protein identification was performed by liquid chromatography electrospray tandem mass spectrometry (LC-ESI-MS/MS), and Se protein profiles were examined in liver (n=30) and heart tissue (n=5) by SEC/UV/ICP-MS detection. Data collected on selenium proteins was evaluated in the context of individual animal trace element concentration, life history, and histological information. Selenium containing protein peak profiles varied in presence and intensity between animals with no pathological findings of cardiomyopathy and animals exhibiting evidence of cardiomyopathy. In particular, one class of proteins, metallothioneins, was found to be associated with Se and was in greater abundance in animals with cardiomyopathy than those with no pathological findings. Profiling Se species with SEC/ICP-MS proved to be a useful tool to identify Se protein pattern differences between heart disease stages in K. breviceps and an approach similar to this may be applied to other species to study Se protein associations with cardiomyopathy.

Establishment of the first humpback whale fibroblast cell lines and their application in chemical risk assessment

This paper reports the first successful derivation and characterization of humpback whale fibroblast cell lines. Primary fibroblasts were isolated from the dermal connective tissue of skin biopsies, cultured at 37 °C and 5% CO2 in the standard mammalian medium DMEM/F12 supplemented with 10% fetal bovine serum (FBS). Of nine initial biopsies, two cell lines were established from two different animals and designated HuWa1 and HuWa2. The cells have a stable karyotype with 2n=44, which has commonly been observed in other baleen whale species. Cells were verified as being fibroblasts based on their spindle-shaped morphology, adherence to plastic and positive immunoreaction to vimentin. Population doubling time was determined to be ∼41 h and cells were successfully cryopreserved and thawed. To date, HuWa1 cells have been propagated 30 times. Cells proliferate at the tested temperatures, 30, 33.5 and 37 °C, but show the highest rate of proliferation at 37 °C. Short-term exposure to para,para'-dichlorodiphenyldichloroethylene (p,p'-DDE), a priority compound accumulating in southern hemisphere humpback whales, resulted in a concentration-dependent loss of cell viability. The effective concentration which caused a 50% reduction in HuWa1 cell viability (EC50 value) was approximately six times greater than the EC50 value for the same chemical measured with human dermal fibroblasts. HuWa1 exposed to a natural, p,p'-DDE-containing, chemical mixture extracted from whale blubber showed distinctively higher sensitivity than to p,p'-DDE alone. Thus, we provide the first cytotoxicological data for humpback whales and with establishment of the HuWa cell lines, a unique in vitro model for the study of the whales' sensitivity and cellular response to chemicals and other environmental stressors.